Optical imaging device

Abstract

The present invention provides an optical imaging device. The optical imaging device includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, a sixth lens with an optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power. The spacer element group includes a fourth spacer element, a fifth spacer element, a sixth spacer element, and a seventh spacer element; it satisfies: 1.4 < f8 / f < 2.9; it satisfies: -4.2 < d7m / (R15 + R16) < -2.2. The present invention solves the problem that in the prior art, an optical imaging device with eight lenses having a strong bending force of the eighth lens has serious stray light at the tail end due to meeting the imaging effect.

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 field of modern optical imaging technology, with the continuous improvement of the requirements for imaging quality, the design and manufacture of optical imaging devices face many challenges. Especially in optical imaging devices with eight lenses, in order to achieve higher imaging effects, the number of lenses is increased to modify aberration and dispersion problems, and the last lens, that is, the eighth lens, needs to have a strong refractive power. However, this design often leads to a serious problem of stray light at the end, thus affecting the imaging quality.

[0003] That is to say, the optical imaging device with eight lenses in the prior art, in which the eighth lens has a strong refractive power, has a problem of not satisfying the imaging effect, resulting in serious stray light at the tail end. Summary of the invention

[0004] The main purpose of the present invention is to provide an optical imaging device to solve the problem in the prior art that the optical imaging device with eight lenses having an eighth lens with a strong refractive power cannot meet the imaging effect but leads to serious stray light at the tail end.

[0005] To achieve the above object, according to one aspect of the present invention, there is provided an optical imaging device, including a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, a sixth lens with an optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between each adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f8 of the eighth lens and the effective focal length f of the optical imaging device satisfy: 1.4 < f8 / f < 2.9; the inner diameter d7m of the image side surface of the seventh spacer element, the curvature radius R15 of the object side surface of the eighth lens, and the curvature radius R16 of the image side surface of the eighth lens satisfy: -4.2 < d7m / (R15 + R16) < -2.2.

[0006] According to another aspect of the present invention, an optical imaging device is provided, including a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative focal power, a second lens with a negative focal power, a third lens with a positive focal power, a fourth lens with a negative focal power, a fifth lens with a positive focal power, a sixth lens with a focal power, a seventh lens with a positive focal power, and an eighth lens with a positive focal power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f8 of the eighth lens and the effective focal length f of the optical imaging device satisfy: 1.4 < f8 / f < 2.9; the inner diameter d7m of the image side surface of the seventh spacer element, the outer diameter D7m of the image side surface of the seventh spacer element, and the object side effective diameter DT81 of the light transmitting portion of the eighth lens satisfy: 0.35 < (D7m - d7m) / DT81 < 0.7.

[0007] According to another aspect of the present invention, there is provided an optical imaging device, including a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, a sixth lens with an optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f7 of the seventh lens and the inner diameter d7s of the object side surface of the seventh spacer element satisfy: 0.40 < f7 / d7s < 4.30; the effective focal length f7 of the seventh lens, the inner diameter d7m of the image side surface of the seventh spacer element and the inner diameter d6s of the object side surface of the sixth spacer element satisfy: 3.05 < f7 / (d7m - d6s) < 36.10.

[0008] Further, the inner diameter d0m of the image side end face of the lens barrel, the inner diameter d7m of the image side surface of the seventh spacer element and the effective focal length f8 of the eighth lens satisfy: 0.4 < (d0m - d7m) / f8 < 1.1.

[0009] Further, the inner diameter d0s of the object side end face of the lens barrel and the inner diameter d0m of the image side end face of the lens barrel satisfy: 1.6 ≤ d0m / d0s < 5.

[0010] Further, the entrance pupil diameter EPD of the optical imaging device and the inner diameter d0m of the image side end face of the lens barrel satisfy: 5.8 < d0m / EPD < 7.6.

[0011] Further, the inner diameter d7m of the image side surface of the seventh spacer element, the outer diameter D7m of the image side surface of the seventh spacer element and the effective diameter DT81 of the object side of the light transmitting part of the eighth lens satisfy: 0.35 < (D7m - d7m) / DT81 < 0.7.

[0012] Further, the inner diameter d6s of the object side surface of the sixth spacer element and the effective focal length f7 of the seventh lens satisfy: 0.2 < d6s / f7 < 2.1; the inner diameter d7s of the object side surface of the seventh spacer element and the effective focal length f8 of the eighth lens satisfy: 0.55 < d7s / f8 ≤ 1.50.

[0013] Further, the inner diameter d4m of the image side surface of the fourth spacer element, the outer diameter D4m of the image side surface of the fourth spacer element and the curvature radius R9 of the object side surface of the fifth lens satisfy: 0.7 < (D4m - d4m) / R9 < 1.7.

[0014] Further, the effective diameter DT51 of the object side of the light-transmitting portion of the fifth lens and the inner diameter d4m of the image side surface of the fourth spacer element satisfy: 1.0 < DT51 / d4m < 1.55; the effective diameter DT42 of the image side of the light-transmitting portion of the fourth lens and the inner diameter d4s of the object side surface of the fourth spacer element satisfy: 0.70 ≤ DT42 / d4s < 1.0.

[0015] Further, the inner diameter d5s of the object side surface of the fifth spacer element and the inner diameter d4s of the object side surface of the fourth spacer element satisfy: 1.25 < d5s / d4s < 1.75; the inner diameter d6s of the object side surface of the sixth spacer element and the inner diameter d5s of the object side surface of the fifth spacer element satisfy: 1.2 < d6s / d5s < 1.4. Further, the inner diameter d5s of the object side surface of the fifth spacer element, the inner diameter d4m of the image side surface of the fourth spacer element and the effective focal length f5 of the fifth lens satisfy: 6.85 < f5 / (d5s - d4m) < 16.7.

[0016] Further, the difference in the center thickness between any two adjacent lenses among the fourth lens to the eighth lens is less than 0.1 mm, and the air gap between any two adjacent lenses among the fourth lens to the eighth lens is less than 0.4 mm.

[0017] Further, the on-axis distance EP56 from the image side surface of the fifth spacer element to the object side surface of the sixth spacer element and the center thickness CT6 of the sixth lens satisfy: 1.0 < EP56 / CT6 ≤ 1.45; the on-axis distance EP67 from the image side surface of the sixth spacer element to the object side surface of the seventh spacer element and the center thickness CT7 of the seventh lens satisfy: 0.8 < EP67 / CT7 < 1.05.

[0018] Further, the on-axis distance Tr7r16 from the object side surface of the fourth lens to the image side surface of the eighth lens and the maximum axial height L from the object side end face of the lens barrel to the image side end face of the lens barrel satisfy: 0.35 < Tr7r16 / L ≤ 0.4.

[0019] Applying the technical solution of the present invention, the optical imaging device of the present application is composed of a lens barrel and eight lenses and multiple spacer elements arranged in the lens barrel. By reasonably arranging the positive and negative optical powers and surface types of the eight lenses, and the positions of the fourth to seventh spacer elements, and setting the optical imaging device to satisfy 1.4 < f8 / f < 2.9, while satisfying the imaging effect, the eighth lens has a strong bending force, which easily generates a certain amount of stray light at the end of the optical imaging device, affecting the imaging quality. Therefore, in the present application, by restricting -4.2 < d7m / (R15 + R16) < -2.2, by controlling the ratio of the inner diameter of the image side of the seventh spacer element to the sum of the curvature radius of the object side of the eighth lens and the curvature radius of the image side of the eighth lens, the convergence of light is completed, and the trend of light at the end of the optical imaging device is controlled. When the light between the seventh lens and the eighth lens is almost parallel light, the reverse of the curvatures of the two is ensured as much as possible, avoiding the situation of large stray light caused by excessive change in light refraction, and improving the stray light at the end. Moreover, when the value of d7m / (R15 + R16) is less than the lower limit value of the present application, d7m will be too large, resulting in insufficient light blocking of marginal rays and increased stray light; when the value of d7m / (R15 + R16) is greater than the upper limit of the present application, it means that R16 is too large, destroying the almost parallel light transmission of light and causing new stray light. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 to the present invention. In the drawings:

[0021] Figure 1 The dimension marking diagram of the optical imaging device of an optional embodiment of the present invention is shown;

[0022] Figure 2 The structural schematic diagram of the optical imaging device of Embodiment 1-1 of the present invention is shown;

[0023] Figure 3 The structural schematic diagram of the optical imaging device of Embodiment 1-2 of the present invention is shown;

[0024] Figure 4 The structural schematic diagram of the optical imaging device of Embodiment 1-3 of the present invention is shown;

[0025] Figures 5 to 7 The axial chromatic aberration curve, astigmatism curve and distortion curve of the optical imaging device of Embodiment 1 of the present invention are respectively shown;

[0026] Figure 8 The structural schematic diagram of the optical imaging device of Embodiment 2-1 of the present invention is shown;

[0027] Fig. 9 A schematic structural diagram of an optical imaging device according to Embodiment 2-2 of the present invention is shown;

[0028] Fig.10 A schematic structural diagram of an optical imaging device according to Embodiment 2-3 of the present invention is shown;

[0029] Figures 11 to 13 The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical imaging device of the second embodiment of the present invention are respectively shown;

[0030] Fig.14 A schematic structural diagram of an optical imaging device according to Embodiment 3-1 of the present invention is shown;

[0031] Fig.15 A schematic structural diagram of an optical imaging device according to Embodiment 3-2 of the present invention is shown;

[0032] Fig.16 A schematic structural diagram of an optical imaging device according to Embodiment 3-3 of the present invention is shown;

[0033] Figures 17 to 19 The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the optical imaging device of the third embodiment of the present invention are respectively shown;

[0034] Fig. 20 A schematic diagram of stray light when an optical imaging device according to an optional embodiment of the present invention satisfies f8 / f=1.67 and d7m / (R15+R16)=-3.79 is shown;

[0035] Fig.21 A schematic diagram of stray light when an optical imaging device according to an optional embodiment of the present invention satisfies f8 / f=1.67 and d7m / (R15+R16)=-4.33 is shown;

[0036] Fig. 22 A schematic diagram of stray light when an optical imaging device according to an optional embodiment of the present invention satisfies f8 / f=1.67 and d7m / (R15+R16)=-1.57 is shown.

[0037] The above drawings include the following reference numerals:

[0038] P0, lens barrel; E1, first lens; S1, object side surface of first lens; S2, image side surface of first lens; E2, second lens; S3, object side surface of second lens; S4, image side surface of second lens; E3, third lens; S5, object side surface of third lens; S6, image side surface of third lens; E4, fourth lens; S7, object side surface of fourth lens; S8, image side surface of fourth lens; E5, fifth lens; S9, object side surface of fifth lens; S10, image side surface of fifth lens; E6 , the sixth lens; S11, the object-side surface of the sixth lens; S12, the image-side surface of the sixth lens; E7, the seventh lens; S13, the object-side surface of the seventh lens; S14, the image-side surface of the seventh lens; E8, the eighth lens; S15, the object-side surface of the eighth lens; S16, the image-side surface of the eighth lens; P1, the first spacing element; P2, the second spacing element; P3, the third spacing element; P4, the fourth spacing element; P5, the fifth spacing element; P6, the sixth spacing element; P7, the seventh spacing element. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 the field, and the positive or negative of the R value (R refers to the radius of curvature in the paraxial region, usually the R value on the lens database (lens data) in optical software) is used to judge the convexity and concavity. Taking the object side surface as an example, when the R value is positive, it is judged to be convex, and when the R value is negative, it is judged to be concave; taking the image side surface as an example, when the R value is positive, it is judged to be concave, and when the R value is negative, it is judged to be convex. In this application, the left side is the object side and the right side is the image side.

[0045] In order to solve the problem that the optical imaging device of an eight-lens system with a relatively strong bending force of the eighth lens in the prior art has serious stray light at the tail end due to meeting the imaging effect, the present invention provides an optical imaging device.

[0046] As Figures 1 to 22 shown, in an optional embodiment of the present application, the optical imaging device includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative focal power, a second lens with a negative focal power, a third lens with a positive focal power, a fourth lens with a negative focal power, a fifth lens with a positive focal power, a sixth lens with a focal power, a seventh lens with a positive focal power, and an eighth lens with a positive focal power. The object side surface of the first lens is concave and the image side surface is convex; the object side surface of the second lens is convex and the image side surface is concave; the object side surface of the third lens is convex and the image side surface is convex; the object side surface of the fifth lens is convex and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave and the image side surface is convex; there is an air gap between each adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f8 of the eighth lens and the effective focal length f of the optical imaging device satisfy: 1.4 < f8 / f < 2.9; the inner diameter d7m of the image side surface of the seventh spacer element, the radius of curvature R15 of the object side surface of the eighth lens, and the radius of curvature R16 of the image side surface of the eighth lens satisfy: -4.2 < d7m / (R15 + R16) < -2.2.

[0047] The optical imaging device of the present application is composed of a lens barrel and eight lenses and multiple spacer elements arranged in the lens barrel. By reasonably arranging the positive and negative optical powers and surface shapes of the eight lenses, and the positions of the fourth to seventh spacer elements, and setting the optical imaging device to satisfy 1.4 < f8 / f < 2.9, while satisfying the imaging effect, the eighth lens has a strong bending force, which easily generates a certain amount of stray light at the end of the optical imaging device, affecting the imaging quality. Therefore, in the present application, by restricting -4.2 < d7m / (R15 + R16) < -2.2, by controlling the ratio of the inner diameter of the image side of the seventh spacer element to the sum of the curvature radius of the object side of the eighth lens and the curvature radius of the image side of the eighth lens, the convergence of light is completed, and the trend of light at the end of the optical imaging device is controlled. When the light between the seventh lens and the eighth lens is nearly parallel light, the reverse curvature of the two is尽可能保证 as much as possible to avoid the situation of large stray light caused by too large a change in light refraction, and the stray light at the end is improved. Moreover, when the value of d7m / (R15 + R16) is less than the lower limit value of the present application, d7m will be too large, resulting in insufficient light blocking of marginal light and increased stray light; when the value of d7m / (R15 + R16) is greater than the upper limit of the present application, it means that R16 is too large, destroying the nearly parallel light transmission of light and resulting in new stray light.

[0048] In addition, referring to Table 1 below, Figure 20 to Figure 22 as shown, on the premise that the optical imaging device satisfies f8 / f = 1.67, Fig. 20 a schematic diagram of stray light when d7m / (R15 + R16) = -3.79 is shown, Fig.21 a schematic diagram of stray light when d7m / (R15 + R16) = -4.33 is shown, Fig. 22 a schematic diagram of stray light when d7m / (R15 + R16) = -1.57 is shown.

[0049] From Figure 20 to Figure 22It can be seen that when d7m / (R15 + R16) = -3.79 is satisfied, the stray light energy is the lowest and the performance is better. When d7m / (R15 + R16) = -4.33 is satisfied, it will cause d7m to be too large, resulting in insufficient light blocking at the edge of the light, leading to an increase in stray light and poor performance. When d7m / (R15 + R16) = -1.57 is satisfied, it will cause R16 to be too large,破坏了光线的近平行光传输,导致杂光新增,表现较差。由此可见,当d7m / (R15 + R16)处于-4.2到-2.2的范围内时,光学成像装置的杂光改善效果最佳。因此,本申请通过约束-4.2 < d7m / (R15 + R16) < -2.2,来完成光线的汇聚,控制光线在光学成像装置的尾端的走势,在第七透镜和第八透镜之间的光线为近平行光的情况下,尽可能保证两者曲率的反向,避免光线折射变化过大导致的杂散光较大的情况,改善了尾端杂散光,提升了成像品质。

[0050] Table 1

[0051]

[0052] In this embodiment, the spacer element group further includes a first spacer element disposed between the first lens and the second lens and in contact with a part of the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in contact with a part of the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in contact with a part of the image side surface of the third lens.

[0053] It should be noted that any one of the first lens to the eighth lens is composed of a light-transmitting part and an edge structure part. The edge structure part is located on the outer peripheral side of the light-transmitting part and is arranged around the circumference of the light-transmitting part. The light-transmitting part is used for the passage of imaging light, while the edge structure part is not used for the passage of imaging light and is used to abut against the lens barrel or an adjacent lens or an adjacent spacer element.

[0054] In this embodiment, the inner diameter d0m of the image side end face of the lens barrel, the inner diameter d7m of the image side surface of the seventh spacer element, and the effective focal length f8 of the eighth lens satisfy: 0.4 < (d0m - d7m) / f8 < 1.1. By reasonably designing the change of the inner diameter of the lens barrel, ensuring an appropriate ratio with the focal length of the eighth lens, the scattering and loss of light inside the optical imaging device are reduced, thereby improving the clarity and contrast of the imaging.

[0055] It should be noted that the part "破坏了光线的近平行光传输,导致杂光新增,表现较差。由此可见,当d7m / (R15 + R16)处于-4.2到-2.2的范围内时,光学成像装置的杂光改善效果最佳。因此,本申请通过约束-4.2 < d7m / (R15 + R16) < -2.2,来完成光线的汇聚,控制光线在光学成像装置的尾端的走势,在第七透镜和第八透镜之间的光线为近平行光的情况下,尽可能保证两者曲率的反向,避免光线折射变化过大导致的杂散光较大的情况,改善了尾端杂散光,提升了成像品质。" in the original text seems to have some incorrect or incomplete expressions. I translated it as best as possible based on the context, but it may need further clarification or correction in the actual content.In this embodiment, the following relationship is satisfied between the inner diameter d0s of the object-side end face of the lens barrel and the inner diameter d0m of the image-side end face of the lens barrel: 1.6 ≤ d0m / d0s < 5. By controlling a certain growth ratio of the inner diameter of the image-side end face of the lens barrel relative to the inner diameter of the object-side end face, it helps to reduce the scattering and loss of light inside the lens barrel; at the same time, the larger inner diameter on the image side can provide stronger support force, which helps to prevent the optical imaging device from deforming or being damaged when subjected to external forces.

[0056] In this embodiment, the following relationship is satisfied between the entrance pupil diameter EPD of the optical imaging device and the inner diameter d0m of the image-side end face of the lens barrel: 5.8 < d0m / EPD < 7.6. By adjusting the ratio of d0m / EPD, the depth of field performance of the optical imaging device can be controlled to a certain extent. At the same time, an appropriate ratio also helps to reduce the scattering and diffraction of light inside the optical imaging device, further improving the imaging quality.

[0057] In this embodiment, the following relationship is satisfied between the inner diameter d7m of the image-side surface of the seventh spacer element, the outer diameter D7m of the image-side surface of the seventh spacer element, and the effective object-side diameter DT81 of the light-transmitting portion of the eighth lens: 0.35 < (D7m - d7m) / DT81 < 0.7. By restricting this conditional expression, it helps to optimize the path of light passing through the seventh spacer element and entering the eighth lens, reduce the scattering and diffraction of light at the edge of the seventh spacer element, thereby improving the clarity and contrast of the image and reducing stray light; at the same time, it also helps to improve the convenience of assembly and debugging of the optical imaging device.

[0058] In this embodiment, the following relationship is satisfied between the inner diameter d6s of the object-side surface of the sixth spacer element and the effective focal length f7 of the seventh lens: 0.2 < d6s / f7 < 2.1; the following relationship is satisfied between the inner diameter d7s of the object-side surface of the seventh spacer element and the effective focal length f8 of the eighth lens: 0.55 < d7s / f8 ≤ 1.50. Restricting these two conditional expressions helps to optimize the path of light passing through the spacer element and the lens, reduce light loss and scattering, and reduce aberrations such as spherical aberration, chromatic aberration, and coma, thereby improving the overall imaging quality of the optical imaging device; at the same time, by reasonably designing the inner diameter ratio, the material consumption and processing difficulty can be reduced while maintaining performance, thus balancing the manufacturing cost.

[0059] In this embodiment, the following relationship is satisfied among the inner diameter d4m of the image side surface of the fourth spacer element, the outer diameter D4m of the image side surface of the fourth spacer element, and the radius of curvature R9 of the object side surface of the fifth lens: 0.7 < (D4m - d4m) / R9 < 1.7. By controlling the ratio of the difference between the outer diameter and the inner diameter of the image side surface of the fourth spacer element to the radius of curvature of the object side surface of the fifth lens, it helps to optimize the path of light entering the fifth lens through the fourth spacer element, reduce the scattering and diffraction of light at the edge of the fourth spacer element, thereby reducing aberrations such as spherical aberration and coma, and thus improving the imaging quality of the optical imaging device to ensure clear and sharp images. At the same time, an appropriate wall thickness ratio also helps to improve the assembly and debugging convenience of the optical imaging device.

[0060] In this embodiment, the following relationship is satisfied between the effective object-side diameter DT51 of the light-transmitting portion of the fifth lens and the inner diameter d4m of the image side surface of the fourth spacer element: 1.0 < DT51 / d4m < 1.55; the following relationship is satisfied between the effective image-side diameter DT42 of the light-transmitting portion of the fourth lens and the inner diameter d4s of the object side surface of the fourth spacer element: 0.70 ≤ DT42 / d4s < 1.0. By constraining these two conditional expressions, it is possible to optimize the path of light entering the fourth lens and the fifth lens through the fourth spacer element, ensure that the light can be transmitted uniformly and efficiently, thereby reducing light loss and scattering. At the same time, it can ensure that the optical imaging device is more compact and coordinated in appearance, which is beneficial to improving the user's visual experience.

[0061] In this embodiment, the following relationship is satisfied between the inner diameter d5s of the object side surface of the fifth spacer element and the inner diameter d4s of the object side surface of the fourth spacer element: 1.25 < d5s / d4s < 1.75; the following relationship is satisfied between the inner diameter d6s of the object side surface of the sixth spacer element and the inner diameter d5s of the object side surface of the fifth spacer element: 1.2 < d6s / d5s < 1.4. By constraining these two conditional expressions, it is beneficial to control the inner diameters of the fourth spacer element, the fifth spacer element, and the sixth spacer element within a reasonable range. On the one hand, it ensures that the normal imaging light can pass through without being affected. On the other hand, it can appropriately intercept the stray light at the end, improve the stray light, and enhance the imaging quality.

[0062] In this embodiment, the following relationship is satisfied among the inner diameter d5s of the object side surface of the fifth spacer element, the inner diameter d4m of the image side surface of the fourth spacer element, and the effective focal length f5 of the fifth lens: 6.85 < f5 / (d5s - d4m) < 16.7. By constraining this conditional expression, it helps to maintain the dimensional coordination between the spacer elements, ensure the compactness and stability of the optical imaging device, can ensure the precise alignment and assembly accuracy between the spacer elements, reduce the errors and debugging time during the assembly process, and at the same time help to intercept the stray light.

[0063] In this embodiment, the difference in the central thickness between any two adjacent lenses among the fourth lens to the eighth lens is greater than 0 mm and less than 0.1 mm, and the air gap between any two adjacent lenses among the fourth lens to the eighth lens is greater than 0 mm and less than 0.4 mm. This air gap is the on-axis air gap. Such a setting can ensure that the optical imaging device maintains a compact structure in the optical axis direction. The smaller lens thickness and air gap can reduce the scattering and loss of light during transmission.

[0064] In this embodiment, the on-axis distance EP56 from the image side surface of the fifth spacer element to the object side surface of the sixth spacer element and the central thickness CT6 of the sixth lens satisfy: 1.0 < EP56 / CT6 ≤ 1.45; the on-axis distance EP67 from the image side surface of the sixth spacer element to the object side surface of the seventh spacer element and the central thickness CT7 of the seventh lens satisfy: 0.8 < EP67 / CT7 < 1.05. By constraining these two conditional expressions, it helps to enhance the overall stability of the optical imaging device. This helps to reduce the deformation and displacement of the optical imaging device when subjected to external forces, thereby maintaining the stability of its optical performance; at the same time, it optimizes the light transmission path inside the optical imaging device. This helps to reduce the scattering and loss of light during transmission and improve the light transmission performance and imaging quality of the optical imaging device.

[0065] In this embodiment, the on-axis distance Tr7r16 from the object side surface of the fourth lens to the image side surface of the eighth lens and the maximum axial height L from the object side end face of the lens barrel to the image side end face of the lens barrel satisfy: 0.35 < Tr7r16 / L ≤ 0.4. Constraining this conditional expression can ensure that the optical imaging device has a more compact structure while maintaining high performance, which helps to reduce the overall size and weight; at the same time, the reasonable ratio of the on-axis distance to the axial height of the lens barrel helps to simplify the assembly and debugging process of the optical imaging device, reduce the errors and debugging time during the assembly process, and improve the production efficiency and quality of the optical imaging device.

[0066] 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. During the simulation using software and / or tools such as the above, the surface profiles of the respective lenses can be appropriately adjusted according to the surface profiles自带 by the software and / or the tools used.

[0067] In addition, in another alternative embodiment of the present application, an optical imaging device is further provided, which includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, a sixth lens with an optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f8 of the eighth lens and the effective focal length f of the optical imaging device satisfy: 1.4 < f8 / f < 2.9; the inner diameter d7m of the image side surface of the seventh spacer element, the outer diameter D7m of the image side surface of the seventh spacer element, and the object side effective diameter DT81 of the light-transmitting portion of the eighth lens satisfy: 0.35 < (D7m - d7m) / DT81 < 0.7.

[0068] The optical imaging device of the present application is composed of a lens barrel, eight lenses and multiple spacer elements disposed in the lens barrel. By reasonably arranging the positive and negative optical powers and surface types of the eight lenses, the positions of the fourth spacer element to the seventh spacer element, and setting the optical imaging device to satisfy 1.4 < f8 / f < 2.9, while satisfying the imaging effect, the eighth lens has a strong bending force, which easily generates certain stray light at the end of the optical imaging device and affects the imaging quality. Therefore, by restricting 0.35 < (D7m - d7m) / DT81 < 0.7, it helps to optimize the path of light entering the eighth lens through the seventh spacer element, reduce the scattering and diffraction of light at the edge of the seventh spacer element, thereby improving the clarity and contrast of imaging and reducing stray light; at the same time, it also helps to improve the convenience of assembly and debugging of the optical imaging device.

[0069] Of course, other parametric forms in the above embodiments may also be included in this embodiment, which will not be elaborated here one by one.

[0070] In addition, in another alternative embodiment of the present application, an optical imaging device is further provided, which includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group consists of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, a sixth lens with an optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between adjacent two of the first lens to the eighth lens; the spacer element group includes a fourth spacer element disposed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element disposed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element disposed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element disposed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens; the effective focal length f7 of the seventh lens and the inner diameter d7s of the object side surface of the seventh spacer element satisfy: 0.40 < f7 / d7s < 4.30; the effective focal length f7 of the seventh lens, the inner diameter d7m of the image side surface of the seventh spacer element and the inner diameter d6s of the object side surface of the sixth spacer element satisfy: 3.05 < f7 / (d7m - d6s) < 36.10.

[0071] The optical imaging device of the present application consists of a lens barrel, eight lenses and a plurality of spacer elements disposed in the lens barrel. By reasonably arranging the positive and negative optical powers and surface types of the eight lenses, the positions of the fourth spacer element to the seventh spacer element, and setting the optical imaging device to satisfy 0.40 < f7 / d7s < 4.30 and 3.05 < f7 / (d7m - d6s) < 36.10, it is beneficial for the sixth spacer element and the seventh spacer element to intercept the stray light generated at the edge positions of the sixth lens and the seventh lens, achieving the purpose of improving the stray light and being beneficial to improving the imaging quality.

[0072] Of course, other parametric forms in the above embodiments may also be included in this embodiment, which will not be elaborated here one by one.

[0073] Optionally, the above optical imaging device may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0074] 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.

[0075] 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.

[0076] Figure 1 A schematic diagram of dimension marking of an optical imaging device of the present application is shown. Figure 1 Parameters such as d0s, d5s, D4m, d4m, d4s, d6s, d7s, d7m, D7m, d0m, EP56, EP67, and L are indicated 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 the specific embodiments are described later.

[0077] 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.

[0078] It should be noted that in the following embodiment 1, there are three examples of embodiment 1-1, embodiment 1-2, and embodiment 1-3; in embodiment 2, there are three examples of embodiment 2-1, embodiment 2-2, and embodiment 2-3; and in embodiment 3, there are three examples of embodiment 3-1, embodiment 3-2, and embodiment 3-3. In the three examples of the same embodiment, the parameters such as the radius of curvature, center thickness, and spacing distance between lenses of the optical imaging device are the same, but the parameters such as the thickness, inner diameter, and outer diameter of the lens barrel and the fourth to seventh spacing elements are different. In other words, the main structure for imaging is the same, but the auxiliary structure for imaging is different.

[0079] It should be noted that any one of the following examples 1 to 3 is applicable to all implementation methods of the present application.

[0080] Embodiment 1

[0081] like Figures 2 to 7 As shown, the optical imaging device of embodiment 1 is described. Figure 2 shows a schematic structural diagram of the optical imaging device of Example 1-1, Figure 3 A schematic diagram of the structure of the optical imaging device of Embodiment 1-2 is shown, Figure 4 A schematic structural diagram of the optical imaging device of Examples 1-3 is shown.

[0082] like Figures 2 to 4 As shown, the optical imaging device includes a lens barrel P0 and 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, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0083] like Figure 2 , which is a schematic diagram of the structure of the optical imaging device of Example 1-1. In this example, the object side surface and image side surface of the first spacer element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and image side surface of the second spacer element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface S5 of the third lens. The object side surface and image side surface of the third spacer element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and image side surface of the fourth spacer element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and image side surface of the fifth spacer element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens. The object side surface and image side surface of the sixth spacer element P6 are respectively in contact with the image side surface S12 of the sixth lens and the object side surface S13 of the seventh lens. The object-side surface and the image-side surface of the seventh spacer element P7 are in partial contact with the image-side surface S14 of the seventh lens and the object-side surface S15 of the eighth lens, respectively.

[0084] like Figure 3 FIG. 1 is a schematic diagram of the structure of the optical imaging device of Example 1-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 1-1, and the relevant description in Example 1-1 may be referred to, and will not be repeated here.

[0085] like Figure 4 , which is a schematic diagram of the structure of the optical imaging device of Example 1-3. In this example, the abutting manner of each spacing element is the same as that of Example 1-1, and the relevant description in Example 1-1 may be referred to, and will not be repeated here.

[0086] In summary, the structural parameters of the optical imaging device of Example 1 under Example 1-1, Example 1-2, and Example 1-3 are shown in Table 2. (Unit: mm)

[0087] Table 2

[0088]

[0089] In Embodiment 1, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a convex surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a concave surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a concave surface, and the image side surface S8 of the fourth lens is a convex surface. The object side surface S9 of the fifth lens is a convex surface, and the image side surface S10 of the fifth lens is a concave surface. The object side surface S11 of the sixth lens is a convex surface, and the image side surface S12 of the sixth lens is a convex surface. The object side surface S13 of the seventh lens is a convex surface, and the image side surface S14 of the seventh lens is a concave surface. The object side surface S15 of the eighth lens is a concave surface, and the image side surface S16 of the eighth lens is a convex surface.

[0090] In Example 1, the effective focal length f1 of the first lens is -129.725 mm, the effective focal length f2 of the second lens is -6.857 mm, the effective focal length f3 of the third lens is 2.931 mm, the effective focal length f4 of the fourth lens is -237.742 mm, the effective focal length f5 of the fifth lens is 7.452 mm, the effective focal length f6 of the sixth lens is 4.919 mm, the effective focal length f7 of the seventh lens is 15.473 mm, and the effective focal length f8 of the eighth lens is 6.320 mm.

[0091] Table 3 shows the basic structural parameters of the optical imaging device of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0092] Table 3

[0093]

[0094] In the first embodiment, the object-side surface and the image-side surface of the first lens E1 to the eighth lens E8 are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0095] Formula (1)

[0096] Wherein, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 4 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, and A22 that can be used for each aspherical mirror surface S1-S16 in Example 1.

[0097] Table 4

[0098]

[0099] 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 imaging lens. 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.

[0100] 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.

[0101] Embodiment 2

[0102] like Figures 8 to 13 As shown, the optical imaging device of the second embodiment is described. Figure 8 A schematic structural diagram of the optical imaging device of Example 2-1 is shown, Fig. 9 A schematic structural diagram of an optical imaging device of Example 2-2 is shown, Fig.10 A schematic structural diagram of the optical imaging device of Example 2-3 is shown.

[0103] like Figures 8 to 10 As shown, the optical imaging device includes a lens barrel P0 and 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, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0104] like Figure 8As shown, it is a structural schematic diagram of the optical imaging device of Example 2-1. In this example, the object side surface and image side surface of the first spacer element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and image side surface of the second spacer element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface S5 of the third lens. The object side surface and image side surface of the third spacer element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and image side surface of the fourth spacer element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and image side surface of the fifth spacer element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens. The object side surface and image side surface of the sixth spacer element P6 are respectively in contact with the image side surface S12 of the sixth lens and the object side surface S13 of the seventh lens. The object-side surface and the image-side surface of the seventh spacer element P7 are in partial contact with the image-side surface S14 of the seventh lens and the object-side surface S15 of the eighth lens, respectively.

[0105] like Fig. 9 , which is a schematic diagram of the structure of the optical imaging device of Example 2-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 2-1, and the relevant description in Example 2-1 may be referred to, and will not be repeated here.

[0106] like Fig.10 , which is a schematic diagram of the structure of the optical imaging device of Example 2-3. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 2-1, and the relevant description in Example 2-1 may be referred to, and will not be repeated here.

[0107] In summary, the structural parameters of the optical imaging device of the second embodiment in the embodiments 2-1, 2-2 and 2-3 are shown in Table 5. (Unit: mm)

[0108] Table 5

[0109]

[0110] In the second embodiment, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a convex surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a concave surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a concave surface. The object side surface S9 of the fifth lens is a convex surface, and the image side surface S10 of the fifth lens is a concave surface. The object side surface S11 of the sixth lens is a convex surface, and the image side surface S12 of the sixth lens is a concave surface. The object side surface S13 of the seventh lens is a convex surface, and the image side surface S14 of the seventh lens is a concave surface. The object side surface S15 of the eighth lens is a concave surface, and the image side surface S16 of the eighth lens is a convex surface.

[0111] In Example 2, the effective focal length f1 of the first lens is -8.521 mm, the effective focal length f2 of the second lens is -21.740 mm, the effective focal length f3 of the third lens is 2.666 mm, the effective focal length f4 of the fourth lens is -9.027 mm, the effective focal length f5 of the fifth lens is 8.554 mm, the effective focal length f6 of the sixth lens is -67.439 mm, the effective focal length f7 of the seventh lens is 1.631 mm, and the effective focal length f8 of the eighth lens is 2.830 mm.

[0112] Table 6 shows the basic structural parameters of the optical imaging device of Example 2, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0113] Table 6

[0114]

[0115] Table 7 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, and A24 that can be used for the aspheric mirror surfaces S1-S16 in Example 2.

[0116] Table 7

[0117]

[0118] Fig.11 The axial chromatic aberration curve of the optical imaging device of the second embodiment is shown, which indicates the deviation of the focusing point of light of different wavelengths after passing through the imaging lens. Fig.12 The astigmatism curve of the optical imaging device of the second embodiment 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 second embodiment is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles.

[0119] according to Figures 11 to 13 It can be seen that the optical imaging device provided in the second embodiment can achieve good imaging quality.

[0120] Embodiment 3

[0121] like Figures 14 to 19 As shown, the optical imaging device of embodiment three is described. Fig.14 A schematic diagram of the structure of the optical imaging device of Example 3-1 is shown, Fig.15 A schematic structural diagram of the optical imaging device of Example 3-2 is shown, Fig.16 A schematic structural diagram of the optical imaging device of Example 3-3 is shown.

[0122] like Figures 14 to 16As shown, the optical imaging device includes a lens barrel P0 and 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, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0123] like Fig.14 , which is a schematic diagram of the structure of the optical imaging device of Example 3-1. In this example, the object side surface and image side surface of the first spacer element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and image side surface of the second spacer element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface S5 of the third lens. The object side surface and image side surface of the third spacer element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and image side surface of the fourth spacer element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and image side surface of the fifth spacer element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens. The object side surface and image side surface of the sixth spacer element P6 are respectively in contact with the image side surface S12 of the sixth lens and the object side surface S13 of the seventh lens. The object-side surface and the image-side surface of the seventh spacer element P7 are in partial contact with the image-side surface S14 of the seventh lens and the object-side surface S15 of the eighth lens, respectively.

[0124] like Fig.15 , which is a schematic diagram of the structure of the optical imaging device of Example 3-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

[0125] like Fig.16 , which is a schematic diagram of the structure of the optical imaging device of Example 3-3. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

[0126] In summary, the structural parameters of the optical imaging device of the third embodiment in the embodiments 3-1, 3-2 and 3-3 are shown in Table 8. (Unit: mm)

[0127] Table 8

[0128]

[0129] In Embodiment 3, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a convex surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a concave surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a concave surface. The object side surface S9 of the fifth lens is a convex surface, and the image side surface S10 of the fifth lens is a concave surface. The object side surface S11 of the sixth lens is a convex surface, and the image side surface S12 of the sixth lens is a concave surface. The object side surface S13 of the seventh lens is a convex surface, and the image side surface S14 of the seventh lens is a convex surface. The object side surface S15 of the eighth lens is a concave surface, and the image side surface S16 of the eighth lens is a convex surface.

[0130] In Example 3, the effective focal length f1 of the first lens is -9.771 mm, the effective focal length f2 of the second lens is -21.955 mm, the effective focal length f3 of the third lens is 2.626 mm, the effective focal length f4 of the fourth lens is -10.889 mm, the effective focal length f5 of the fifth lens is 11.580 mm, the effective focal length f6 of the sixth lens is -17.958 mm, the effective focal length f7 of the seventh lens is 1.523 mm, and the effective focal length f8 of the eighth lens is 2.362 mm.

[0131] Table 9 shows the basic structural parameter table of the optical imaging device of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0132] Table 9

[0133]

[0134] Table 10 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, and A24 that can be used for the aspheric mirror surfaces S1-S16 in Example 3.

[0135] Table 10

[0136]

[0137] Fig.17 The axial chromatic aberration curve of the optical imaging device of the third embodiment is shown, which indicates the deviation of the focusing point of light of different wavelengths after passing through the imaging lens. Fig.18 The astigmatism curve of the optical imaging device of the third embodiment 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 the third embodiment is shown, which represents the distortion magnitude values ​​corresponding to different field of view angles.

[0138] according to Figures 17 to 19It can be seen that the optical imaging device provided in the third embodiment can achieve good imaging quality.

[0139] In summary, Embodiment 1 to Embodiment 3 respectively satisfy the relationship shown in Table 11.

[0140] Table 11

[0141]

[0142] Table 12 shows the effective focal lengths of the lenses of the optical imaging devices of Examples 1 to 3.

[0143] Table 12

[0144]

[0145] The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging device described above.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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: It includes a lens barrel, a lens group and a spacer element group arranged in the lens barrel. The lens group is composed of eight lenses. The eight lenses are, in order from the object side to the image side, a first lens with negative optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with optical power, a seventh lens with positive optical power, and an eighth lens with positive optical power. The object side surface of the first lens is concave, and the image side surface is convex; the object side surface of the second lens is convex, and the image side surface is concave; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is concave; the object side surface of the sixth lens is convex; the object side surface of the seventh lens is convex; the object side surface of the eighth lens is concave, and the image side surface is convex; there is an air gap between adjacent two of the first lens to the eighth lens. The spacer element group includes a fourth spacer element placed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, a fifth spacer element placed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens, a sixth spacer element placed between the sixth lens and the seventh lens and in partial contact with the image side surface of the sixth lens, and a seventh spacer element placed between the seventh lens and the eighth lens and in partial contact with the image side surface of the seventh lens. The effective focal length f8 of the eighth lens and the effective focal length f of the optical imaging device satisfy: 1.4 < f8 / f < 2.9; the inner diameter d7m of the image side surface of the seventh spacer element, the curvature radius R15 of the object side surface of the eighth lens, and the curvature radius R16 of the image side surface of the eighth lens satisfy: -4.2 < d7m / (R15 + R16) < -2.

2.

2. The optical imaging device according to claim 1, characterized in that: The inner diameter d0m of the image side end face of the lens barrel, the inner diameter d7m of the image side surface of the seventh spacer element, and the effective focal length f8 of the eighth lens satisfy: 0.4 < (d0m - d7m) / f8 < 1.

1.

3. The optical imaging device according to claim 1, characterized in that: The inner diameter d0s of the object side end face of the lens barrel and the inner diameter d0m of the image side end face of the lens barrel satisfy: 1.6 ≤ d0m / d0s < 5.

4. The optical imaging device according to claim 1, characterized in that: The entrance pupil diameter EPD of the optical imaging device and the inner diameter d0m of the image side end face of the lens barrel satisfy: 5.8 < d0m / EPD < 7.

6.

5. The optical imaging device according to claim 1, characterized in that: The inner diameter d7m of the image side surface of the seventh spacer element, the outer diameter D7m of the image side surface of the seventh spacer element, and the effective object side diameter DT81 of the light transmitting part of the eighth lens satisfy: 0.35 < (D7m - d7m) / DT81 < 0.

7.

6. The optical imaging device according to claim 1, wherein the inner diameter d6s of the object side surface of the sixth spacer element and the effective focal length f7 of the seventh lens satisfy: 0.2 < d6s / f7 < 2.1; The inner diameter d7s of the object side of the seventh spacing element and the effective focal length f8 of the eighth lens satisfy the following relationship: 0.55 <d7s / f8≤1.50。 7. The optical imaging device according to claim 1, characterized in that: An inner diameter d4m of the image side surface of the fourth spacer element, an outer diameter D4m of the image side surface of the fourth spacer element, and a curvature radius R9 of the object side surface of the fifth lens satisfy the following relationship: 0.7<(D4m-d4m) / R9<1.

7.

8. The optical imaging device according to claim 1, characterized in that: The effective diameter DT51 of the light-transmitting portion of the fifth lens on the object side and the inner diameter d4m of the image-side surface of the fourth spacer element satisfy: 1.0 <DT51 / d4m<1.55; The image-side effective diameter DT42 of the light-transmitting portion of the fourth lens element and the inner diameter d4s of the object-side surface of the fourth spacer element satisfy the following: 0.70≤DT42 / d4s<1.

0.

9. The optical imaging device according to claim 1, characterized in that: The inner diameter d5s of the object side surface of the fifth spacing element and the inner diameter d4s of the object side surface of the fourth spacing element satisfy: 1.25 <d5s / d4s<1.75; The inner diameter d6s of the object side surface of the sixth spacing element and the inner diameter d5s of the object side surface of the fifth spacing element satisfy: 1.2 <d6s / d5s<1.4。 10. The optical imaging device according to claim 1, characterized in that: The inner diameter d5s of the object side surface of the fifth spacing element, the inner diameter d4m of the image side surface of the fourth spacing element and the effective focal length f5 of the fifth lens satisfy the following relationship: 6.85 <f5 / (d5s-d4m)<16.7。 11. The optical imaging device according to claim 1, characterized in that: The difference in center thickness between two adjacent lenses among the fourth lens to the eighth lens is less than 0.1 mm, and the air space between two adjacent lenses among the fourth lens to the eighth lens is less than 0.4 mm.

12. The optical imaging device according to claim 11, characterized in that: The axial distance EP56 from the image side surface of the fifth spacer element to the object side surface of the sixth spacer element and the center thickness CT6 of the sixth lens satisfy: 1.0 <EP56 / CT6≤1.45; The axial distance EP67 from the image side surface of the sixth spacer element to the object side surface of the seventh spacer element and the center thickness CT7 of the seventh lens satisfy: 0.8 <EP67 / CT7<1.05。 13. The optical imaging device according to claim 11, characterized in that: The axial distance Tr7r16 from the object side surface of the fourth lens to the image side surface of the eighth lens and the maximum axial height L from the object side end surface of the lens barrel to the image side end surface of the lens barrel satisfy: 0.35 <Tr7r16 / L≤0.4。

Images