Optical imaging device

Abstract

The utility model discloses an optical imaging device. The optical imaging device comprises a lens cone, an eight-piece lens group and a spacer group, wherein the eight-piece lens group and the spacer group are arranged in the lens cone; the eight-piece lens group comprises a first lens with positive focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with focal power, a fifth lens with focal power and a sixth lens with positive focal power which are sequentially arranged from the object side to the image side along the optical axis; the seventh lens has positive focal power; the eighth lens has negative focal power; the spacer group comprises a fifth spacer which is arranged on the image side surface of the fifth lens and is in contact with the image side surface of the fifth lens, and a sixth spacer which is arranged on the image side surface of the sixth lens and is in contact with the image side surface of the sixth lens; the maximum length L of the lens barrel in the direction of the optical axis and the total effective focal length f of the optical imaging device meet the following conditions: 1.40 lt; l / flt; 1.80, 1.80; an interval EP56 between the fifth spacer and the sixth spacer along the optical axis and an air interval T56 between the fifth lens and the sixth lens on the optical axis satisfy: 3.00 lt; eP 56 / T56lt; 28.00, 28.00, 28.00.

Description

Technical Field

[0001] The present application relates to the field of optical devices, and particularly to an optical imaging device including eight lenses. Background Art

[0002] In recent years, with the continuous development of science and technology, users have higher and higher requirements for portable electronic devices such as smart phones, especially in terms of the performance of imaging lenses. For example, when the optical main parameters of the imaging lens meet the design requirements, higher requirements are put forward for the assembly stability of the imaging lens.

[0003] At present, the eight-piece optical imaging device has become the mainstream. There is a large step difference between the fifth lens and the sixth lens in this optical imaging device, which will cause the fifth lens to be more sensitive, and the fifth lens is prone to deformation problems during the assembly process, thus affecting the assembly stability of the optical imaging device. Summary of the Utility Model

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

[0005] One aspect of the present application provides such an optical imaging device, which includes a lens barrel, an eight-piece lens group and a spacer group disposed in the lens barrel; the eight-piece lens group includes a first lens with a positive focal power, a second lens with a positive focal power, a third lens with a negative focal power, a fourth lens with a focal power, a fifth lens with a focal power, a sixth lens with a positive focal power, a seventh lens with a positive focal power, and an eighth lens with a negative focal power arranged in sequence from the object side to the image side along the optical axis; the spacer group includes a fifth spacer disposed on the image side surface of the fifth lens and in contact with the image side surface of the fifth lens, and a sixth spacer disposed on the image side surface of the sixth lens and in contact with the image side surface of the sixth lens; the maximum length L of the lens barrel in the direction of the optical axis and the total effective focal length f of the optical imaging device satisfy: 1.40 < L / f < 1.80; the interval EP56 of the fifth spacer and the sixth spacer along the optical axis and the air interval T56 of the fifth lens and the sixth lens on the optical axis satisfy: 3.00 < EP56 / T56 < 28.00.

[0006] According to an exemplary embodiment of the present application, the effective focal length f7 of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.10 < |R14 / f7| ≤ 0.25; the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R16 of the image side surface of the eighth lens, the inner diameter d0s of the object side end surface of the lens barrel and the inner diameter d0m of the image side end surface of the lens barrel satisfy: 0.40 < d0m / R16 - d0s / R1 < 5.10.

[0007] According to an exemplary embodiment of the present application, the curvature radius R9 of the object side surface of the fifth lens, the refractive index N5 of the fifth lens, and the inner diameter d5s of the object side surface of the fifth spacer satisfy: 0.70 <R9 / (d5s×N5)<3.50。

[0008] According to an exemplary embodiment of the present application, the curvature radius R10 of the image side surface of the fifth lens and the outer diameter D5m of the image side surface of the fifth spacer satisfy: 0.60 <D5m / R10<1.40。

[0009] According to an exemplary embodiment of the present application, the combined focal length f23 of the second lens and the third lens and the maximum length L of the lens barrel along the optical axis satisfy: 1.80 <f23 / L<9.00。

[0010] According to an exemplary embodiment of the present application, the outer diameter D5s of the object side surface of the fifth spacer and the interval EP56 between the fifth spacer and the sixth spacer along the optical axis satisfy: 6.50 <D5s / EP56<19.50。

[0011] According to an exemplary embodiment of the present application, the combined focal length f56 of the fifth lens and the sixth lens and the inner diameter d5s of the object side surface of the fifth spacer satisfy: 1.10 <d5s / f56<1.50。

[0012] According to an exemplary embodiment of the present application, the spacer group further includes a first spacer disposed on the image side of the first lens and in contact with the image side of the first lens, wherein the center thickness CT1 of the first lens on the optical axis and the interval EP01 between the object side end surface of the lens barrel and the first spacer along the optical axis satisfy: 2.10 <EP01 / CT1<3.50。

[0013] According to an exemplary embodiment of the present application, the spacer group further includes a first spacer disposed on the image side surface of the first lens and in contact with the image side surface of the first lens, wherein the maximum effective semi-aperture DT11 of the object side surface of the first lens and the outer diameter D1s of the object side surface of the first spacer satisfy: 1.20 <D1s / (2×DT11)<1.60。

[0014] According to an exemplary embodiment of the present application, the spacer group also includes a first spacer placed on the image side surface of the first lens and in contact with the image side surface of the first lens, a second spacer placed on the image side surface of the second lens and in contact with the image side surface of the second lens, and a third spacer placed on the image side surface of the third lens and in contact with the image side surface of the third lens, wherein the interval EP12 between the first spacer and the second spacer along the optical axis, the interval EP23 between the second spacer and the third spacer along the optical axis, the center thickness CT1 of the first lens on the optical axis and the center thickness CT2 of the second lens on the optical axis satisfy: 1.00≤(EP12+EP23) / (CT1+CT2)<1.50.

[0015] According to an exemplary embodiment of the present application, the spacer group also includes a third spacer disposed on the image side surface of the third lens and in contact with the image side surface of the third lens, and a fourth spacer disposed on the image side surface of the fourth lens and in contact with the image side surface of the fourth lens, wherein the center thickness CT4 of the fourth lens on the optical axis, the inner diameter d3s of the object side surface of the third spacer, and the inner diameter d4s of the object side surface of the fourth spacer satisfy: 1.80<(d4s-d3s) / CT4<2.50.

[0016] According to an exemplary embodiment of the present application, the spacer group also includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens, wherein an air gap T78 between the seventh lens and the eighth lens on the optical axis, an inner diameter d7m of the image side surface of the seventh spacer, and an inner diameter d0m of the image side end surface of the lens barrel satisfy: 0.10<(d0m-d7m) / T78<36.

[0017] According to an exemplary embodiment of the present application, the spacer group also includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens, wherein a curvature radius R13 of the object side surface of the seventh lens, a curvature radius R14 of the image side surface of the seventh lens, an inner diameter d7s of the object side surface of the seventh spacer, and an inner diameter d7m of the image side surface of the seventh spacer satisfy: 0.60<|R13 / d7s|+|R14 / d7m|<1.10.

[0018] According to an exemplary embodiment of the present application, the spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens, wherein an axial distance SAG81 from an intersection of an outer diameter D7m of the image side surface of the seventh spacer and the object side surface of the eighth lens and the optical axis to a maximum effective half-aperture vertex of the object side surface of the eighth lens satisfies: 3.00 <D7m / SAG81<10.00。

[0019] According to an exemplary embodiment of the present application, the spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens, wherein an inner diameter d7m of the image side surface of the seventh spacer and a maximum effective semi-aperture DT81 of the object side surface of the eighth lens satisfy: 0.90 <d7m / (2×DT81)<1.10。

[0020] The optical imaging device provided in the present application adopts eight lenses. By controlling the ratio of the maximum length of the lens barrel along the optical axis to the total effective focal length of the optical imaging device, the total optical length of the optical imaging device can be constrained within a reasonable range. However, in this case, there is a large step difference between the fifth lens and the sixth lens, and the spacing between the fifth spacer and the sixth spacer along the optical axis is greater than the air spacing between the fifth lens and the sixth lens on the optical axis. If EP56 / T56 is too large, it will affect the overall length and cause uneven force distribution on the entire lens barrel, which will cause the fifth lens to be easily deformed under pressure during the assembly process. If EP56 / T56 is too small, the sixth lens will be more deformed and subjected to greater stress, which will make it more likely to have eccentricity problems and affect light convergence. It can be seen that EP56 / T56 that is too large or too small will deteriorate the assembly stability. Therefore, by constraining the ratio of the spacing between the fifth spacer and the sixth spacer along the optical axis to the air spacing between the fifth lens and the sixth lens on the optical axis within a certain range, it helps to improve the assembly stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings, in which:

[0022] Figure 1 A parameter annotation diagram of an optical imaging device according to the present application is shown;

[0023] Figure 2A A schematic diagram showing stress distribution of each lens when the optical imaging device according to the present application satisfies EP56 / T56=27.9 is shown;

[0024] Figure 2B A schematic diagram showing stress distribution of each lens when the optical imaging device according to the present application satisfies EP56 / T56=31.8 is shown;

[0025] Figure 2C A schematic diagram showing stress distribution of each lens when the optical imaging device according to the present application satisfies EP56 / T56=2.6 is shown;

[0026] Figure 3 A schematic structural diagram of an optical imaging device according to Embodiment 1 of the present application is shown;

[0027] Figure 4A schematic structural diagram of an optical imaging device according to Embodiment 2 of the present application is shown;

[0028] Figure 5 A schematic structural diagram of an optical imaging device according to Embodiment 3 of the present application is shown;

[0029] FIG. 6A to FIG. 6D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the optical imaging device according to Embodiment 1, 2 or 3 of the present application are respectively shown;

[0030] Figure 7 A schematic structural diagram of an optical imaging device according to Embodiment 4 of the present application is shown;

[0031] Figure 8 A schematic structural diagram of an optical imaging device according to Embodiment 5 of the present application is shown;

[0032] Fig. 9 A schematic structural diagram of an optical imaging device according to Embodiment 6 of the present application is shown;

[0033] FIG. 10A to FIG. 10D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the optical imaging device according to Embodiment 4, 5 or 6 of the present application are respectively shown;

[0034] Fig.11 A schematic structural diagram of an optical imaging device according to Embodiment 7 of the present application is shown;

[0035] Fig.12 A schematic structural diagram of an optical imaging device according to Embodiment 8 of the present application is shown;

[0036] Fig.13 A schematic structural diagram of an optical imaging device according to Embodiment 9 of the present application is shown; and

[0037] FIG. 14A to FIG. 14D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging device according to Embodiment 7, 8 or 9 of the present application are respectively shown. DETAILED DESCRIPTION

[0038] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numerals refer to the same elements.

[0039] 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.

[0040] 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.

[0041] In this article, 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 surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0042] It should also be understood that the terms "including" and / or "having", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when describing the embodiments of the present application, the term "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0043] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0044] 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 application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] Figure 1 Schematic diagram of the structural arrangement and some parameters of the optical imaging device according to an exemplary embodiment of the present application. Figure 1, D1s represents the outer diameter of the object side surface of the first spacer, d3s represents the inner diameter of the object side surface of the third spacer, d4s represents the inner diameter of the object side surface of the fourth spacer, d5s represents the inner diameter of the object side surface of the fifth spacer, D5s represents the outer diameter of the object side surface of the fifth spacer, D5m represents the outer diameter of the image side surface of the fifth spacer, d7s represents the inner diameter of the object side surface of the seventh spacer, d7m represents the inner diameter of the image side surface of the seventh spacer, D7m represents the outer diameter of the image side surface of the seventh spacer, d0s represents the inner diameter of the object side end surface of the lens barrel, d0m represents the inner diameter of the image side end surface of the lens barrel, EP01 represents the interval between the object side end surface of the lens barrel and the first spacer along the optical axis, EP12 represents the interval between the first spacer and the second spacer along the optical axis, EP23 represents the interval between the second spacer and the third spacer along the optical axis, EP56 represents the interval between the fifth spacer and the sixth spacer along the optical axis, and L represents the maximum length of the lens barrel along the direction of the optical axis.

[0046] refer to Figures 3 to 5 , Figures 7 to 9 as well as Figures 11 to 13 In a first aspect of the present application, an optical imaging device is provided, which may include an eight-piece lens group, which may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side to the image side along the optical axis. Among the first lens to the eighth lens, any two adjacent lenses may have an air gap between them.

[0047] In an exemplary embodiment, the first lens may have positive power. The second lens may have positive power. The third lens may have negative power. The fourth lens may have positive power or negative power. The fifth lens may have positive power or negative power. The sixth lens may have positive power. The seventh lens may have positive power. The eighth lens may have negative power.

[0048] In example embodiments, the object-side surface of the first lens may be a convex surface, and the image-side surface may be a concave surface.

[0049] In example embodiments, the object-side surface of the second lens may be a convex surface, and the image-side surface may be a convex surface or a concave surface.

[0050] In example embodiments, the object-side surface of the third lens may be a convex surface or a concave surface, and the image-side surface may be a concave surface.

[0051] In example embodiments, the object-side surface of the fourth lens may be a convex surface, and the image-side surface may be a concave surface.

[0052] In example embodiments, the object-side surface of the fifth lens may be a convex surface, and the image-side surface may be a concave surface.

[0053] In example embodiments, the object-side surface of the sixth lens may be a convex surface, and the image-side surface may be a convex surface.

[0054] In example embodiments, the object-side surface of the seventh lens may be a concave surface, and the image-side surface may be a convex surface.

[0055] In example embodiments, the object-side surface of the eighth lens may be a convex surface or a concave surface, and the image-side surface may be a concave surface.

[0056] In an exemplary embodiment, the image side surface of the seventh lens has no inflection point, and the point on the image side surface of the seventh lens having the smallest axial distance from the image side end surface of the barrel is the intersection of the image side surface of the seventh lens and the optical axis.

[0057] In an exemplary embodiment, the optical imaging device may further include a stop disposed between the object side and the first lens.

[0058] In an exemplary embodiment, the optical imaging device may further include a spacer group, and the spacer group may include one or more of a first spacer, a second spacer, a third spacer, a fourth spacer, a fifth spacer, a sixth spacer, and a seventh spacer. The first spacer may be placed on the image side of the first lens and at least partially contact the image side of the first lens. The second spacer may be placed on the image side of the second lens and at least partially contact the image side of the second lens. The third spacer may be placed on the image side of the third lens and at least partially contact the image side of the third lens. The fourth spacer may be placed on the image side of the fourth lens and at least partially contact the image side of the fourth lens. The fifth spacer may be placed on the image side of the fifth lens and at least partially contact the image side of the fifth lens. The sixth spacer may be placed on the image side of the sixth lens and at least partially contact the image side of the sixth lens. The seventh spacer may be placed on the image side of the seventh lens and at least partially contact the image side of the seventh lens. The reasonable use of spacers can effectively avoid the risk of stray light, reduce interference with image quality, and thereby improve the imaging quality of the optical imaging device; at the same time, it can also improve the bearing stability of the lens.

[0059] In an exemplary embodiment, the optical imaging device may further include a lens barrel, and the eight-piece lens group and the spacer group are placed in the lens barrel. The lens barrel may include an object side end face, an image side end face, an outer annular surface, and an inner annular surface, wherein the end face of the lens barrel closest to the object side is the object side end face of the lens barrel, and the end face of the lens barrel closest to the image side is the image side end face of the lens barrel; in the direction perpendicular to the optical axis, the surface of the lens barrel farthest from the optical axis is the outer annular surface, and the surface of the lens barrel closest to the optical axis is the inner annular surface. The inner annular surface of the lens barrel is stepped, and the inner diameter of the inner annular surface increases from the object side end face to the image side end face.

[0060] In an exemplary embodiment, the maximum length L of the lens barrel in the direction of the optical axis and the total effective focal length f of the optical imaging device may satisfy: 1.40 < L / f < 1.80. By controlling the ratio of the maximum length of the lens barrel in the direction of the optical axis to the total effective focal length of the optical imaging device, the overall optical length of the optical imaging device can be constrained within a reasonable range, preventing problems such as film abrasion in the optical imaging device under external conditions such as high temperature, high humidity, and dropping.

[0061] In an exemplary embodiment, the interval EP56 between the fifth spacer and the sixth spacer along the optical axis and the air interval T56 between the fifth lens and the sixth lens on the optical axis may satisfy: 3.00 < EP56 / T56 < 28.00. When the optical imaging device satisfies "1.40 < L / f < 1.80", there is a large step difference between the fifth lens and the sixth lens, and the interval between the fifth spacer and the sixth spacer along the optical axis is greater than the air interval between the fifth lens and the sixth lens on the optical axis. If EP56 / T56 is too large, it will affect the overall length and cause uneven force distribution on the entire lens barrel, which will cause the edge of the fifth lens to be easily deformed under pressure during assembly. If EP56 / T56 is too small, the sixth lens will have greater deformation and be subjected to greater stress, making it easier to generate an eccentricity problem, affecting the light convergence. It can be seen that either too large or too small EP56 / T56 will make the assembly stability worse. Therefore, by constraining the ratio of the interval between the fifth spacer and the sixth spacer along the optical axis to the air interval between the fifth lens and the sixth lens on the optical axis within a certain range, it helps to improve the assembly stability.

[0062] Figure 2A FIG. is a schematic diagram of the stress distribution of each lens when the optical imaging device has EP56 / T56 = 27.9, that is, the optical imaging device satisfies 3.00 < EP56 / T56 < 28.00. When the optical imaging device does not satisfy 3.00 < EP56 / T56 < 28.00, for example Figure 2B FIG. is a schematic diagram of the stress distribution of each lens under the condition that the optical imaging device has EP56 / T56 = 31.8; and for example Figure 2C FIG. is a schematic diagram of the stress distribution of each lens under the condition that the optical imaging device has EP56 / T56 = 2.6.

[0063] In FIG. 2A to FIG. 2C the darker the color, the greater the stress existing in the lens. From Figure 2B and Figure 2C it can be seen that when EP56 / T56 = 31.8 or EP56 / T56 = 2.6, the assembly bearing surface of the fifth lens and the center of the fifth lens are not in the same plane, which will cause obvious stress concentration at the assembly bearing position of the fifth lens. The fifth lens is prone to abnormal problems such as tilting and deformation during assembly, resulting in poor assembly stability of the optical imaging device. From Figure 2A Looking at it, when EP56 / T56 = 27.9, the assembly supporting surface of the fifth lens and the center of the fifth lens are approximately on the same plane, which is beneficial to reducing the stress concentration phenomenon at the assembly supporting position of the fifth lens and improving the assembly stability of the optical imaging device. It can be seen that when the optical imaging device satisfies "3.00 < EP56 / T56 < 28.00", the risk of deformation of the fifth lens during assembly can be reduced, and the assembly stability of the optical imaging device can be improved.

[0064] In an exemplary embodiment, the effective focal length f7 of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens can satisfy: 0.10 < |R14 / f7| ≤ 0.25. By reasonably configuring the ratio of the radius of curvature of the image side surface of the seventh lens to the effective focal length of the seventh lens, the field of view angle range of the optical imaging device can meet the requirements, thereby ensuring that the optical imaging device can capture scenes with a large field of view.

[0065] In an exemplary embodiment, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R16 of the image side surface of the eighth lens, 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: 0.40 < d0m / R16 - d0s / R1 < 5.10. When the optical imaging device satisfies "0.10 < |R14 / f7| ≤ 0.25", the optical imaging device has a relatively large field of view angle. However, the larger the field of view angle of the optical imaging device, the larger the outer diameter of the first lens will be, and it is easy to have a deviation between the central axis of the first lens and the central axes of other lenses during assembly, thus affecting the imaging quality of the optical imaging device. Therefore, by controlling the mutual relationship between the radius of curvature of the object side surface of the first lens, the radius of curvature of the image side surface of the eighth lens, the inner diameter of the object side end face of the lens barrel, and the inner diameter of the image side end face of the lens barrel, the outer diameters of the first lens and the eighth lens can be restricted within a reasonable range, avoiding the phenomenon of excessive deviation of the central axes of each lens, reducing the sensitivity of the first lens and the eighth lens, and improving the MTF yield of the optical imaging device.

[0066] Next, in combination with Table a, Table b, and Table c, the relationship between the eccentricity value of the lens and the sensitivity is further described. In Tables a to c, the symbols "+" and "-" of +1μm and -1μm represent the direction of the field curvature movement of the MTF curve, and "F" in "0.1F", "0.2F", "0.3F", "0.4F", "0.5F", "0.6F", "0.7F", "0.8F", "0.9F", and "1.0F" represents the field of view.

[0067] Table a shows the sensitivities of the decentration values of the first lens and the eighth lens to the field curvature in the T direction when the optical imaging device satisfies d0m / R16 - d0s / R1 = 0.508. For example, at a 1.0 field of view, when the decentration value of the first lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 0μm; when the decentration value of the first lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is 0.10μm. When the decentration value of the eighth lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 0μm; when the decentration value of the eighth lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is 0.1μm.

[0068] Table b shows the sensitivities of the decentration values of the first lens and the eighth lens to the field curvature in the T direction when the optical imaging device satisfies d0m / R16 - d0s / R1 = 0.281. For example, at a 1.0 field of view, when the decentration value of the first lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 0.06μm; when the decentration value of the first lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is -0.36μm. When the decentration value of the eighth lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 1.18μm; when the decentration value of the eighth lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is -0.74μm.

[0069] Table c shows the sensitivities of the decentration values of the first lens and the eighth lens to the field curvature in the T direction when the optical imaging device satisfies d0m / R16 - d0s / R1 = 6.692. For example, at a 1.0 field of view, when the decentration value of the first lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 0.18μm; when the decentration value of the first lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is -0.55μm. When the decentration value of the eighth lens deviates by +1μm from the designed value, the offset of the field curvature in the T direction is 2.10μm; when the decentration value of the eighth lens deviates by -1μm from the designed value, the offset of the field curvature in the T direction is -1.85μm.

[0070] Judging from the data provided in Table a, Table b, and Table c, compared with d0m / R16 - d0s / R1 = 0.281 and d0m / R16 - d0s / R1 = 6.692, when the optical imaging device satisfies d0m / R16 - d0s / R1 = 0.508, the sensitivities of the decentration values of the first lens and the eighth lens to the field curvature in the T direction are significantly reduced. It can be seen that when the optical imaging device satisfies "0.40 < d0m / R16 - d0s / R1 < 5.10", the sensitivities of the decentration values of the first lens and the eighth lens to the field curvature in the T direction can be reduced, and the MTF yield of the optical imaging device can be improved.

[0071]

[0072] Table a

[0073]

[0074] Table b

[0075]

[0076] Table c

[0077] In an exemplary embodiment, the radius of curvature R9 of the object side surface of the fifth lens, the refractive index N5 of the fifth lens, and the inner diameter d5s of the object side surface of the fifth spacer may satisfy: 0.70 < R9 / (d5s×N5) < 3.50. By controlling the above conditional expression, the radius of curvature and the refractive index of the object side surface of the fifth lens can be constrained within a reasonable range, ensuring that the light rays in the marginal field of view have an appropriate field angle. At the same time, by cooperating with restricting the inner diameter of the object side surface of the fifth spacer, the off-axis aberration of the optical imaging device can be corrected, and the imaging quality of the optical imaging device can be improved.

[0078] In an exemplary embodiment, the radius of curvature R10 of the image side surface of the fifth lens and the outer diameter D5m of the image side surface of the fifth spacer may satisfy: 0.60 < D5m / R10 < 1.40. Reasonably configuring the ratio of the outer diameter of the image side surface of the fifth spacer to the radius of curvature of the image side surface of the fifth lens can ensure the structural uniformity of the fifth lens, which is beneficial to the processing and forming of the fifth lens; at the same time, it can also restrict the outer diameter of the image side surface of the fifth spacer, so that the fifth spacer can block the stray light generated at the edge of the fifth lens, improving the imaging picture quality of the optical imaging device.

[0079] In an exemplary embodiment, the combined focal length f23 of the second lens and the third lens and the maximum length L of the lens barrel along the optical axis direction may satisfy: 1.80 < f23 / L < 9.00. Reasonably configuring the ratio of the combined focal length of the second lens and the third lens to the maximum length of the lens barrel along the optical axis direction is beneficial to balancing the aberration caused by the too large field angle of the optical imaging device while shortening the overall optical length of the optical imaging device.

[0080] In an exemplary embodiment, the outer diameter D5s of the object side surface of the fifth spacer and the interval EP56 between the fifth spacer and the sixth spacer along the optical axis may satisfy: 6.50 < D5s / EP56 < 19.50. Reasonably configuring the ratio of the outer diameter of the object side surface of the fifth spacer to the interval between the fifth spacer and the sixth spacer along the optical axis can respectively constrain the edge thickness of the sixth lens and the outer diameter of the object side surface of the fifth spacer within a certain range. While ensuring the formability of the sixth lens, it is beneficial to improve the assembly stability between the sixth lens and the fifth spacer and reduce the sensitivity of the optical imaging device.

[0081] In an exemplary embodiment, the combined focal length f56 of the fifth lens and the sixth lens and the inner diameter d5s of the object side surface of the fifth spacer may satisfy: 1.10 < d5s / f56 < 1.50. By reasonably configuring the ratio of the inner diameter of the object side surface of the fifth spacer to the combined focal length of the fifth lens and the sixth lens, the difference in the outer diameter dimensions between the fifth lens and the sixth lens can be constrained within a certain range, avoiding a large assembly step difference between the fifth lens and the sixth lens caused by an excessive difference in the outer diameter dimensions of the fifth lens and the sixth lens, improving the assembly stability of the optical imaging device, and further reducing the sensitivity of the optical imaging device.

[0082] In an exemplary embodiment, the central thickness CT1 of the first lens on the optical axis and the interval EP01 between the object side end surface of the lens barrel and the first spacer along the optical axis may satisfy: 2.10 < EP01 / CT1 < 3.50. By reasonably configuring the ratio of the interval between the object side end surface of the lens barrel and the first spacer along the optical axis to the central thickness of the first lens on the optical axis, the thickness ratio of the first lens can be constrained within a certain range, ensuring the stability of the central thickness and the edge thickness of the first lens under external conditions such as high temperature, high humidity, and dropping, so that the imaging effect of the optical imaging device is less affected by external conditions.

[0083] In an exemplary embodiment, the maximum effective semi-aperture DT11 of the object side surface of the first lens and the outer diameter D1s of the object side surface of the first spacer may satisfy: 1.20 < D1s / (2×DT11) < 1.60. By reasonably configuring the ratio of the outer diameter of the object side surface of the first spacer to the maximum effective semi-aperture of the object side surface of the first lens, the radial step difference between the first lens and the first spacer can be constrained within a certain range, preventing the problem of poor assembly stability caused by an excessive radial step difference between the first lens and the first spacer during the assembly process.

[0084] In an exemplary embodiment, the interval EP12 between the first spacer and the second spacer along the optical axis, the interval EP23 between the second spacer and the third spacer along the optical axis, the central thickness CT1 of the first lens on the optical axis, and the central thickness CT2 of the second lens on the optical axis may satisfy: 1.00 ≤ (EP12 + EP23) / (CT1 + CT2) < 1.50. By controlling the above conditional expression, the thickness ratio of the central thickness of the first lens and the second lens to the edge thickness region of the mechanism part can be constrained within a reasonable range, which is beneficial to ensuring the shape rationality of the first lens and the second lens, and thus ensuring that the molding of the first lens and the second lens does not exceed the processing limit.

[0085] In an exemplary embodiment, the central thickness CT4 of the fourth lens on the optical axis, the inner diameter d3s of the object side surface of the third spacer, and the inner diameter d4s of the object side surface of the fourth spacer may satisfy: 1.80 < (d4s - d3s) / CT4 < 2.50. By controlling the above conditional expression, the optical power of the fourth lens can be constrained, the sensitivity of the fourth lens can be reduced, and at the same time, by restricting the inner diameter of the object side surface of the third spacer and the inner diameter of the object side surface of the fourth spacer, an appropriate field of view angle of the optical imaging device can be ensured, thereby ensuring that the optical imaging device can capture scenes in a large field of view range.

[0086] In an exemplary embodiment, the air gap T78 between the seventh lens and the eighth lens on the optical axis, the inner diameter d7m of the image side surface of the seventh spacer, and the inner diameter d0m of the image side end surface of the lens barrel may satisfy: 0.10 < (d0m - d7m) / T78 < 36. By controlling the above conditional expression, the wall thickness uniformity of the object side end and the image side end of the lens barrel can be effectively controlled, so that the lens barrel has sufficient stiffness and strength, ensuring the formability of the lens barrel and the stability during the assembly process. At the same time, by restricting the air gap between the seventh lens and the eighth lens on the optical axis, the air gap and the edge air gap between the seventh lens and the eighth lens can be limited within a reasonable range, improving the stability of the air gap between the seventh lens and the eighth lens under external conditions such as high temperature, high humidity, and dropping.

[0087] In an exemplary embodiment, the curvature radius R13 of the object side surface of the seventh lens, the curvature radius R14 of the image side surface of the seventh lens, the inner diameter d7s of the object side surface of the seventh spacer, and the inner diameter d7m of the image side surface of the seventh spacer may satisfy: 0.60 < |R13 / d7s| + |R14 / d7m| < 1.10. By controlling the above conditional expression, the shape of the seventh lens can be constrained, which is beneficial to the processing of the seventh lens and ensuring the stability of the forming process of the seventh lens; at the same time, the inner diameters of the object side surface and the image side surface of the seventh spacer can also be restricted, so that the seventh spacer can effectively intercept non-imaging light rays and improve the imaging quality of the optical imaging device.

[0088] In an exemplary embodiment, the outer diameter D7m of the image side surface of the seventh spacer and the axial distance SAG81 from the intersection of the object side surface of the eighth lens and the optical axis to the vertex of the maximum effective semi-aperture of the object side surface of the eighth lens may satisfy: 3.00 < D7m / SAG81 < 10.00. By controlling the above conditional expression, the thickness uniformity of the edge part (non-effective diameter part) of the eighth lens can be controlled, improving the forming stability of the eighth lens; at the same time, the outer diameter of the image side surface of the seventh spacer can also be constrained within a reasonable range, ensuring that the eighth lens is uniformly stressed during the process of bearing against the seventh spacer and preventing problems such as deformation of the eighth lens due to uneven stress during the assembly process.

[0089] In an exemplary embodiment, the inner diameter d7m of the image side surface of the seventh spacer and the maximum effective semi-aperture DT81 of the object side surface of the eighth lens may satisfy: 0.90 < d7m / (2×DT81) < 1.10. By reasonably configuring the ratio of the inner diameter of the image side surface of the seventh spacer to the maximum effective semi-aperture of the object side surface of the eighth lens, the radial step difference between the eighth lens and the seventh spacer can be constrained within a certain range, preventing the problem of poor assembly stability caused by an excessive radial step difference between the eighth lens and the seventh spacer during the assembly process.

[0090] The optical imaging device according to the above embodiment of the present application may employ eight lenses and at least one spacer. By reasonably allocating the parameters of each lens, each spacer, and the lens barrel, a large field of view angle of the optical imaging device can be achieved, the risk of stray light of the optical imaging device can be reduced, and the processability, molding stability, assembly stability, and imaging quality of the optical imaging device can be improved.

[0091] In an embodiment of the present application, at least one of the surfaces of each of the first lens to the eighth lens is an aspherical surface. The characteristic of an aspherical lens is that the curvature continuously changes from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, the aberration that appears during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, both the object side surface and the image side surface of each of the first lens to the eighth lens are aspherical surfaces.

[0092] The second aspect of the present application provides an optical imaging device, which includes a lens barrel and an eight-piece lens group disposed within the lens barrel. The eight-piece lens group includes a first lens with a positive focal power, a second lens with a positive focal power, a third lens with a negative focal power, a fourth lens with a focal power, a fifth lens with a focal power, a sixth lens with a positive focal power, a seventh lens with a positive focal power, and an eighth lens with a negative focal power, which are arranged in sequence from the object side to the image side along the optical axis. The object side surface of the first lens may be convex, and the image side surface may be concave. The object side surface of the second lens may be convex. The image side surface of the third lens may be concave. The object side surface of the fourth lens may be convex, and the image side surface may be concave. The object side surface of the fifth lens may be convex, and the image side surface may be concave. The object side surface of the sixth lens may be convex, and the image side surface may be convex. The object side surface of the seventh lens may be concave, and the image side surface may be convex. The image side surface of the eighth lens may be concave. The image side surface of the seventh lens does not have an inflection point, and the point on the image side surface of the seventh lens with the minimum axial distance from the image side end surface of the lens barrel is the intersection of the image side surface of the seventh lens and the optical axis.

[0093] Among them, the effective focal length f7 of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens can satisfy: 0.10 < |R14 / f7| ≤ 0.25; the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R16 of the image side surface of the eighth lens, the inner diameter d0s of the object side end surface of the lens barrel, and the inner diameter d0m of the image side end surface of the lens barrel can satisfy: 0.40 < d0m / R16 - d0s / R1 < 5.10. Reasonably configuring the ratio of the radius of curvature of the image side surface of the seventh lens to the effective focal length of the seventh lens can enable the field of view angle range of the optical imaging device to meet the requirements, thereby ensuring that the optical imaging device can capture scenes in a large field of view range. However, the larger the field of view angle of the optical imaging device, the larger the outer diameter of the first lens will be, and it is easy to have a deviation between the central axis of the first lens and the central axes of other lenses during assembly, thereby affecting the imaging quality of the optical imaging device. Therefore, by controlling the mutual relationship between the radius of curvature of the object side surface of the first lens, the radius of curvature of the image side surface of the eighth lens, the inner diameter of the object side end surface of the lens barrel, and the inner diameter of the image side end surface of the lens barrel, the outer diameters of the first lens and the eighth lens can be constrained within a reasonable range, avoiding the phenomenon of excessive deviation of the central axes of each lens, reducing the sensitivity of the first lens and the eighth lens, and improving the MTF yield of the optical imaging device.

[0094] Those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses and spacers constituting the optical imaging device can be changed to obtain the various results and advantages described in this specification.

[0095] The following further describes specific embodiments of the optical imaging device applicable to the above embodiments with reference to the accompanying drawings.

[0096] Example 1

[0097] The following refers to Figure 3 Describe the optical imaging device according to Embodiment 1 of the present application.

[0098] As Figure 3 shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group disposed in the lens barrel. The eight-piece lens group sequentially includes, from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8. The aperture stop STO can be disposed between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6, and a seventh spacer P7. The spacer can block the excess light during the imaging process from entering the next lens, and at the same time enables the lens to better bear against the lens barrel, enhancing the structural stability of the optical imaging device.

[0099] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has positive focal power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative focal power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has positive focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has positive focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has positive focal power, and its object side surface S13 is concave, and its image side surface S14 is convex. The eighth lens E8 has negative focal power, and its object side surface S15 is concave, and its image side surface S16 is concave. The filter has an object side surface S17 (not shown) and an image side surface S18 (not shown). Light from the object passes through the surfaces S1 to S18 in sequence and is finally imaged on an imaging surface S19 (not shown).

[0100] Table 1 shows the basic parameter table of the optical imaging device of Example 1, wherein the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0101]

[0102]

[0103] Table 1

[0104] In this embodiment, the total effective focal length f of the optical imaging device is 5.50 mm, and the aperture number Fno of the optical imaging device is 1.59.

[0105] In this embodiment, the object side surface and the image side surface of any lens among the first lens E1 to the eighth lens E8 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0106]

[0107] 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 optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., 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 aspheric surface. Table 2 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A 10 , A 12 , A 14 , A 16 , A 18 , A 20 , A22 , A 24 , A 26 and A 28 .

[0108]

[0109]

[0110] Table 2

[0111] Example 2

[0112] The following reference Figure 4 Describe the optical imaging device according to Example 2 of the present application.

[0113] like Figure 4 As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0114] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 1, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 1, and the aspheric coefficient table is the same as Table 2. The difference between this embodiment and Embodiment 1 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0115] Example 3

[0116] The following reference Figure 5 Describe the optical imaging device according to Example 3 of the present application.

[0117] like Figure 5As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0118] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 1, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 1, and the aspheric coefficient table is the same as Table 2. The difference between this embodiment and Embodiment 1 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0119] Fig. 6A The axial chromatic aberration curves of the optical imaging devices of Examples 1, 2, and 3 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Figure 6B The astigmatism curves of the optical imaging devices of Examples 1, 2, and 3 are shown, which represent the meridional image curvature and sagittal image curvature corresponding to different image heights. Figure 6C The distortion curves of the optical imaging devices of Examples 1, 2, and 3 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.6D The magnification chromatic aberration curves of the optical imaging devices of Examples 1, 2, and 3 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the optical imaging device. FIG. 6A to FIG. 6D It can be seen that the optical imaging devices provided in Examples 1, 2, and 3 can achieve good imaging quality.

[0120] Example 4

[0121] The following reference Figure 7 Describe the optical imaging device according to Example 4 of the present application.

[0122] like Figure 7As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 in order from the object side to the image side along the optical axis. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7. The spacer can block excess light in the imaging process from entering the next lens, and at the same time make the lens and the lens barrel better supported, thereby enhancing the structural stability of the optical imaging device.

[0123] The first lens E1 has positive focal power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has positive focal power, and its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has negative focal power, and its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens E4 has negative focal power, and its object side surface S7 is convex, and its image side surface S8 is concave. The fifth lens E5 has negative focal power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive focal power, and its object side surface S11 is convex, and its image side surface S12 is convex. The seventh lens E7 has positive focal power, and its object side surface S13 is concave, and its image side surface S14 is convex. The eighth lens E8 has negative focal power, and its object side surface S15 is convex, and its image side surface S16 is concave. The filter has an object side surface S17 (not shown) and an image side surface S18 (not shown). Light from the object passes through the surfaces S1 to S18 in sequence and is finally imaged on an imaging surface S19 (not shown).

[0124] Table 3 shows the basic parameter table of the optical imaging device of Example 4, wherein the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0125]

[0126] Table 3

[0127] In this embodiment, the total effective focal length f of the optical imaging device is 5.30 mm, and the aperture number Fno of the optical imaging device is 1.71.

[0128] In this embodiment, 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. Table 4 lists the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A2 10 , A 12 , A 14 , A 16 , A18 , A 20 , A 22 , A 24 , A 26 and A 28 .

[0129]

[0130]

[0131] Table 4

[0132] Example 5

[0133] The following reference Figure 8 Describe the optical imaging device according to Example 5 of the present application.

[0134] like Figure 8 As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0135] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 4, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 3, and the aspheric coefficient table is the same as Table 4. The difference between this embodiment and Embodiment 4 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0136] Example 6

[0137] The following reference Fig. 9 Describe the optical imaging device according to Example 6 of the present application.

[0138] like Fig. 9As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0139] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 4, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 3, and the aspheric coefficient table is the same as Table 4. The difference between this embodiment and Embodiment 4 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0140] Fig. 10A The axial chromatic aberration curves of the optical imaging devices of Examples 4, 5, and 6 are shown, which represent the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Fig. 10B The astigmatism curves of the optical imaging devices of Examples 4, 5, and 6 are shown, which represent the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 10C The distortion curves of the optical imaging devices of Examples 4, 5 and 6 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Fig. 10D The magnification chromatic aberration curves of the optical imaging devices of Examples 4, 5, and 6 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the optical imaging device. FIG. 10A to FIG. 10D It can be seen that the optical imaging devices provided in Examples 4, 5 and 6 can achieve good imaging quality.

[0141] Example 7

[0142] The following reference Fig.11 Describe the optical imaging device according to Example 7 of the present application.

[0143] like Fig.11As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 in order from the object side to the image side along the optical axis. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7. The spacer can block excess light in the imaging process from entering the next lens, and at the same time make the lens and the lens barrel better supported, thereby enhancing the structural stability of the optical imaging device.

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

[0145] Table 5 shows the basic parameter table of the optical imaging device of Example 7, wherein the units of the radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0146]

[0147]

[0148] Table 5

[0149] In this embodiment, the total effective focal length f of the optical imaging device is 5.30 mm, and the aperture number Fno of the optical imaging device is 1.59.

[0150] In this embodiment, 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. Table 6 lists the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A62, A71, A72, A73, A74, A75 10 , A 12, A 14 , A 16 , A 18 , A 20 , A 22 , A 24 , A 26 and A 28 .

[0151]

[0152]

[0153] Table 6

[0154] Example 8

[0155] The following reference Fig.12 Describe the optical imaging device according to Example 8 of the present application.

[0156] like Fig.12 As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0157] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 7, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 5, and the aspheric coefficient table is the same as Table 6. The difference between this embodiment and Embodiment 7 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0158] Example 9

[0159] The following reference Fig.13 Describe the optical imaging device according to Example 9 of the present application.

[0160] like Fig.13As shown, the optical imaging device includes a lens barrel and an eight-piece lens group and a spacer group placed in the lens barrel. The eight-piece lens group includes, in order from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8. The aperture STO can be arranged between the object side and the first lens E1. The spacer group includes a first spacer P1, a second spacer P2, a third spacer P3, a fourth spacer P4, a fifth spacer P5, a sixth spacer P6 and a seventh spacer P7.

[0161] The structure of the lens of this embodiment is the same as that of the lens of Embodiment 7, that is, the basic parameter table of the optical imaging device of this embodiment is the same as Table 5, and the aspheric coefficient table is the same as Table 6. The difference between this embodiment and Embodiment 7 is that the structural dimensions of at least some of the elements in the lens barrel, the first spacer P1, the second spacer P2, the third spacer P3, the fourth spacer P4, the fifth spacer P5, the sixth spacer P6, and the seventh spacer P7 are different.

[0162] Fig.14A The axial chromatic aberration curves of the optical imaging devices of Examples 7, 8, and 9 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the optical imaging device. Fig. 14B The astigmatism curves of the optical imaging devices of Examples 7, 8, and 9 are shown, which represent the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 14C The distortion curves of the optical imaging devices of Examples 7, 8 and 9 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.14D The magnification chromatic aberration curves of the optical imaging devices of Examples 7, 8, and 9 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the optical imaging device. FIG. 14A to FIG. 14D It can be seen that the optical imaging devices provided in Examples 7, 8 and 9 can achieve good imaging quality.

[0163] Table 7 shows the values ​​of parameters such as D1s, d3s, d4s, d5s, D5s, D5m, d7s, d7m, D7m, d0s, d0m, EP01, EP12, EP23, EP56, L, DT11, DT81 and SAG81 of each embodiment in embodiments 1-9. The above parameters can be calculated according to Figure 1 The units of the parameters listed in Table 7 are all mm.

[0164]

[0165]

[0166] Table 7

[0167] Table 8 shows the values ​​of the conditional expressions of each of Examples 1 to 9.

[0168] Conditional / Example 1 2 3 4 5 6 7 8 9 L / f 1.51 1.51 1.51 1.48 1.50 1.49 1.69 1.79 1.74 EP56 / T56 3.33 3.33 3.33 12.57 12.57 15.78 27.88 27.88 12.71 (d4s-d3s) / CT4 2.09 2.09 2.02 1.90 1.90 1.99 2.31 2.27 2.16 (d0m-d7m) / T78 4.48 4.48 5.36 4.56 0.18 4.89 25.99 25.76 35.38 EP01 / CT1 2.37 2.16 2.37 2.21 2.60 2.42 2.25 3.34 3.34 R9 / (d5s×N5) 0.76 0.76 0.76 2.19 2.19 2.19 3.32 3.32 3.23 |R13 / d7s|+|R14 / d7m| 1.04 1.04 1.04 0.69 0.72 0.70 0.67 0.67 0.67 D5m / R10 0.68 0.68 0.81 1.39 1.39 1.22 1.15 1.08 1.08 d0m / R16-d0s / R1 0.51 0.50 0.59 3.79 1.41 3.95 4.60 4.38 5.03 (EP12+EP23) / (CT1+CT2) 1.00 1.14 1.00 1.27 1.40 1.31 1.20 1.33 1.33 f23 / L 8.69 8.69 8.69 1.92 1.89 1.90 5.43 5.13 5.27 D5s / EP56 16.33 16.33 19.27 18.85 18.85 13.10 7.14 6.69 14.68 d5s / f56 1.45 1.45 1.45 1.18 1.18 1.18 1.12 1.12 1.15 D1s / (2×DT11) 1.41 1.24 1.41 1.55 1.34 1.33 1.51 1.47 1.47 D7m / SAG81 3.88 4.65 4.65 4.74 3.42 4.74 9.67 9.53 9.53 d7m / (2×DT81) 1.03 1.03 1.03 0.98 0.95 0.98 1.01 1.01 1.01 |R14 / f7| 0.25 0.25 0.25 0.17 0.17 0.17 0.21 0.21 0.21

[0169] Table 8

[0170] 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 device (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.

[0171] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other.

Claims

1. An optical imaging device, characterized in that: include: An eight-piece lens group, comprising a first lens with positive power, a second lens with positive power, a third lens with negative power, a fourth lens with power, a fifth lens with power, a sixth lens with positive power, a seventh lens with positive power, and an eighth lens with negative power, which are arranged in order from the object side to the image side along the optical axis; a spacer group, comprising a fifth spacer disposed on the image side surface of the fifth lens and in contact with the image side surface of the fifth lens, and a sixth spacer disposed on the image side surface of the sixth lens and in contact with the image side surface of the sixth lens; and A lens barrel, wherein the eight-piece lens group and the spacer group are placed in the lens barrel; The maximum length L of the lens barrel along the direction of the optical axis and the total effective focal length f of the optical imaging device satisfy the following conditions: 1.40 <L / f<1.80; The interval EP56 between the fifth spacer and the sixth spacer along the optical axis and the air interval T56 between the fifth lens and the sixth lens on the optical axis satisfy: 3.00 <EP56 / T56<28.00。 2. The optical imaging device according to claim 1, characterized in that: The effective focal length f7 of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.10<|R14 / f7|≤0.25; the curvature radius R1 of the object side surface of the first lens, the curvature radius R16 of the image side surface of the eighth lens, the inner diameter d0s of the object side end surface of the lens barrel and the inner diameter d0m of the image side end surface of the lens barrel satisfy: 0.40 <d0m / R16-d0s / R1<5.10。 3. The optical imaging device according to claim 1, characterized in that: The curvature radius R9 of the object side surface of the fifth lens, the refractive index N5 of the fifth lens and the inner diameter d5s of the object side surface of the fifth spacer satisfy: 0.70 <R9 / (d5s×N5)<3.50。 4. The optical imaging device according to claim 1, characterized in that: The curvature radius R10 of the image side surface of the fifth lens and the outer diameter D5m of the image side surface of the fifth spacer satisfy: 0.60 <D5m / R10<1.40。 5. The optical imaging device according to claim 1, characterized in that: The combined focal length f23 of the second lens and the third lens and the maximum length L of the lens barrel along the direction of the optical axis satisfy: 1.80 <f23 / L<9.00。 6. The optical imaging device according to claim 1, characterized in that: The outer diameter D5s of the object side surface of the fifth spacer and the interval EP56 between the fifth spacer and the sixth spacer along the optical axis satisfy: 6.50 <D5s / EP56<19.50。 7. The optical imaging device according to claim 1, characterized in that: The combined focal length f56 of the fifth lens and the sixth lens and the inner diameter d5s of the object side surface of the fifth spacer satisfy: 1.10 <d5s / f56<1.50。 8. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer set further includes a first spacer disposed on the image side surface of the first lens and in contact with the image side surface of the first lens. The central thickness CT1 of the first lens on the optical axis and the interval EP01 between the object side end surface of the lens barrel and the first spacer along the optical axis satisfy: 2.10 <EP01 / CT1<3.50。 9. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer set further includes a first spacer disposed on the image side surface of the first lens and in contact with the image side surface of the first lens. The maximum effective semi-aperture DT11 of the object side surface of the first lens and the outer diameter D1s of the object side surface of the first spacer satisfy: 1.20 <D1s / (2×DT11)<1.60。 10. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a first spacer disposed on the image side surface of the first lens and in contact with the image side surface of the first lens, a second spacer disposed on the image side surface of the second lens and in contact with the image side surface of the second lens, and a third spacer disposed on the image side surface of the third lens and in contact with the image side surface of the third lens. Among them, the interval EP12 between the first spacer and the second spacer along the optical axis, the interval EP23 between the second spacer and the third spacer along the optical axis, the center thickness CT1 of the first lens on the optical axis and the center thickness CT2 of the second lens on the optical axis satisfy: 1.00≤(EP12+EP23) / (CT1+CT2)<1.

50.

11. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a third spacer disposed on the image side surface of the third lens and in contact with the image side surface of the third lens, and a fourth spacer disposed on the image side surface of the fourth lens and in contact with the image side surface of the fourth lens. The center thickness CT4 of the fourth lens on the optical axis, the inner diameter d3s of the object side surface of the third spacer, and the inner diameter d4s of the object side surface of the fourth spacer satisfy: 1.80<(d4s-d3s) / CT4<2.

50.

12. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens. The air gap T78 between the seventh lens and the eighth lens on the optical axis, the inner diameter d7m of the image side surface of the seventh spacer and the inner diameter d0m of the image side end surface of the lens barrel satisfy: 0.10<(d0m-d7m) / T78<36.

13. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens. Among them, a curvature radius R13 of the object side surface of the seventh lens, a curvature radius R14 of the image side surface of the seventh lens, an inner diameter d7s of the object side surface of the seventh spacer, and an inner diameter d7m of the image side surface of the seventh spacer satisfy: 0.60<|R13 / d7s|+|R14 / d7m|<1.

10.

14. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens. The axial distance SAG81 from the intersection of the outer diameter D7m of the image side surface of the seventh spacer and the object side surface of the eighth lens and the optical axis to the maximum effective half-aperture vertex of the object side surface of the eighth lens satisfies: 3.00 <D7m / SAG81<10.00。 15. The optical imaging device according to any one of claims 1 to 7, characterized in that: The spacer group further includes a seventh spacer disposed on the image side surface of the seventh lens and in contact with the image side surface of the seventh lens. The inner diameter d7m of the image side surface of the seventh spacer and the maximum effective half-aperture DT81 of the object side surface of the eighth lens satisfy: 0.90 <d7m / (2×DT81)<1.10。

Images