Optical image capturing system

Abstract

The invention provides an optical imaging system. The optical imaging system comprises a lens cone, a lens group and a spacing element group, and the lens group is composed of six lenses. The six lenses are sequentially a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power, a fourth lens with positive focal power, a fifth lens with negative focal power and a sixth lens with positive focal power; the following conditions are met: 116.00 degree lt; a FOVlt; 146.30 DEG C, 146.30 DEG C; the following conditions are satisfied: 31.10 lt; d4m / (T45 + CP4) lt; 47.15, 47.15; the following conditions are satisfied: 4.00 lt; eP 45 / CT 5lt; 5.78). According to the invention, the problem that a six-piece optical imaging system in the prior art is large in control field angle and small in tail end lens thickness, so that the surface type change of the tail end lens in the reliability verification process is large, and the variation of the MTF peak value and the field curvature of the tail end lens is large is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging devices, and in particular, to an optical imaging system. Background Art

[0002] With the continuous development of technology, optical imaging systems have been widely used in many fields, such as smartphones, vehicle-mounted cameras, security monitoring, etc. Among them, six-piece optical imaging systems have gradually become a mainstream optical imaging system because they can better balance the factors of imaging quality and cost.

[0003] In practical applications, in order to meet the requirements of different scenarios, optical imaging systems usually constrain the field of view angle FOV to be relatively large, as well as the optical power and thickness of the lenses, especially by controlling the thickness of the end lens to be relatively small to match the application requirements. However, in this case, during the reliability verification process of the optical imaging system, the surface shape of the end lens changes greatly, which in turn leads to large changes in the main evaluation indexes such as the MTF peak value and field curvature of the end lens, affecting the stability of the overall performance.

[0004] That is to say, the six-piece optical imaging system in the prior art has the problems that the field of view angle is controlled to be relatively large and the thickness of the end lens is relatively small, resulting in a large change in the surface shape of the end lens during the reliability verification process, and in turn leading to large changes in the MTF peak value and field curvature of the end lens. Summary of the Invention

[0005] The main object of the present invention is to provide an optical imaging system to solve the problems that the six-piece optical imaging system in the prior art has a relatively large controlled field of view angle and a relatively small thickness of the end lens, resulting in a large change in the surface shape of the end lens during the reliability verification process, and in turn leading to large changes in the MTF peak value and field curvature of the end lens.

[0006] In order to achieve the above object, according to one aspect of the present invention, an optical imaging system is 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 six lenses. The six 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 positive optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power; among them, among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system; 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, and 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; the maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°; the inner diameter d4m of the image side surface of the fourth spacer element, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the maximum axial thickness CP4 of the fourth spacer element satisfy: 31.10 < d4m / (T45 + CP4) < 47.15; the central thickness CT5 of the fifth lens on the optical axis and the spacer distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: 4.00 < EP45 / CT5 < 5.78.

[0007] According to another aspect of the present invention, an optical imaging system is 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 six lenses. The six lenses are, in order from the object side to the image side, a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with positive optical power. The object side surface of the first lens is convex, and the image side surface is concave. The object side surface of the second lens is convex. The object side surface of the third lens is concave, and the image side surface is convex. The object side surface of the fourth lens is convex, and the image side surface is convex. The object side surface of the fifth lens is concave. The object side surface of the sixth lens is convex, and the image side surface is concave. Among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system. 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, and 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. The maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°. The inner diameter d4m of the image side surface of the fourth spacer element, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the maximum axial thickness CP4 of the fourth spacer element satisfy: 31.10 < d4m / (T45 + CP4) < 47.15. The effective focal length f5 of the fifth lens and the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: -2.77 < f5 / EP45 < -1.36.

[0008] According to another aspect of the present invention, there is provided an optical imaging system, including a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six 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 positive optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power; the object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is convex; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is concave; the object side surface of the sixth lens is convex, and the image side surface is concave; wherein, among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system; 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, and 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; the maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°; the effective focal length f5 of the fifth lens and the maximum axial thickness CP5 of the fifth spacer element satisfy: -110.30 < f5 / CP5 < -74.00; the inner diameter d4m of the image side surface of the fourth spacer element and the maximum axial thickness CP4 of the fourth spacer element satisfy: 39.25 < d4m / T45 < 68.80.

[0009] Further, the inner diameter d0m of the image side end surface of the lens barrel and the entrance pupil diameter EPD of the optical imaging system satisfy: 4.39 < d0m / EPD < 7.38.

[0010] Further, the effective focal length f5 of the fifth lens and the spacing distance EP45 on the optical axis between the fourth spacer element and the fifth spacer element satisfy: -2.77 < f5 / EP45 < -1.36.

[0011] Further, the inner diameter d5m of the image side surface of the fifth spacer element, the outer diameter D5m of the image side surface of the fifth spacer element, and the central thickness CT6 of the sixth lens on the optical axis satisfy: 3.14 < (D5m - d5m) / CT6 < 4.95.

[0012] Further, the outer diameter D5m of the image side surface of the fifth spacer element and the effective focal length f6 of the sixth lens satisfy: 2.09 < D5m / f6 < 3.68; the inner diameter d5m of the image side surface of the fifth spacer element and the curvature radius R11 of the object side surface of the sixth lens satisfy: 1.69 < d5m / R11 < 2.35.

[0013] Further, the air gap T56 between the fifth lens and the sixth lens on the optical axis and the maximum axial thickness CP5 of the fifth spacer element satisfy: 10.50 < T56 / CP5 < 17.09.

[0014] Further, the spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The central thickness CT4 of the fourth lens on the optical axis and the spacer distance EP34 from the third spacer element to the fourth spacer element on the optical axis satisfy: 1.45 < CT4 / EP34 < 3.25.

[0015] Further, the spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The maximum axial thickness CP3 of the third spacer element and the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis and the effective radius vertex of the object-side surface of the first lens satisfy: 1.50 < CP3 / SAG41 < 2.60.

[0016] Further, the spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The central thickness CT3 of the third lens on the optical axis, the effective focal length f3 of the third lens, and the maximum axial thickness CP3 of the third spacer element satisfy: 2.30 < f3 / (CT3 + CP3) < 6.15.

[0017] Further, the spacer element group further includes a second spacer element disposed between the second lens and the third lens and in contact with the image-side portion of the second lens. The inner diameter d2m of the image-side surface of the second spacer element and the central thickness CT3 of the third lens on the optical axis satisfy: 2.02 < d2m / CT3 < 2.83.

[0018] Further, the spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The curvature radius R5 of the object-side surface of the third lens and the curvature radius R6 of the image-side surface of the third lens satisfy: 1.01 < R5 / R6 < 2.23; the inner diameter d3s of the object-side surface of the third spacer element and the curvature radius R6 of the image-side surface of the third lens satisfy: -2.75 < d3s / R6 < -1.26.

[0019] Further, the spacer element group further includes a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface portion of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface portion of the third lens. The following conditions are satisfied between the inner diameter d3s of the object-side surface of the third spacer element and the inner diameter d2s of the object-side surface of the second spacer element: 1.21 < d3s / d2s < 2.30; and the following conditions are satisfied between the inner diameter d2s of the object-side surface of the second spacer element and the air gap T23 between the second lens and the third lens on the optical axis: 6.92 < d2s / T23 < 9.93.

[0020] Further, the spacer element group further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface portion of the first lens, and a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface portion of the second lens. The following conditions are satisfied between the air gap T12 between the first lens and the second lens on the optical axis and the spacer distance EP12 between the first spacer element and the second spacer element on the optical axis: 1.29 < T12 / EP12 < 2.22.

[0021] Further, the spacer element group further includes a third spacer element and a third auxiliary spacer element disposed between the third lens and the fourth lens. The third spacer element is in contact with the image-side surface portion of the third lens, and the third auxiliary spacer element is in contact with the image-side surface portion of the third spacer element. The following conditions are satisfied between the combined focal length f34 of the third lens and the fourth lens, the maximum axial thickness CP3 of the third spacer element, and the maximum axial thickness CP3b of the third auxiliary spacer element: 1.50 < f34 / (CP3 + CP3b) < 2.50.

[0022] Further, the spacer element group further includes a first spacer element disposed between the first lens and the second lens and in contact with the image-side surface portion of the first lens, a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface portion of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface portion of the third lens. Among the first spacer element, the second spacer element, the third spacer element, the fourth spacer element, and the fifth spacer element, the third spacer element has the largest maximum axial thickness on the optical axis.

[0023] Applying the technical solution of the present invention, the optical imaging system of the present application consists of a lens barrel and six lenses and multiple spacer elements arranged in the lens barrel. By setting that the first lens has a negative focal power, the second lens has a positive focal power, the third lens has a positive focal power, the fourth lens has a positive focal power, the fifth lens has a negative focal power, and the sixth lens has a positive focal power, by reasonably restricting the positive and negative of the focal power of each lens, and at the same time setting the center thickness of the fifth lens to be the smallest, and restricting 116.00° < FOV < 146.30°, however, when the FOV is relatively large and the thickness design of the fifth lens is relatively thin, it is easy to cause a large change in the surface shape of the fifth lens during the reliability verification, and further cause a large change in the MTF peak value and the field curvature of the fifth lens, affecting the stability of the overall performance. Therefore, the present application can ensure the overall structural reliability of the fifth lens by restricting 31.10 < d4m / (T45 + CP4) < 47.15 and 4.00 < EP45 / CT5 < 5.78, ensure that when dealing with the reliability test, the internal stress level distribution of the optical imaging system is more uniform, the deformation amount of the fifth lens is smaller, so as to ensure that the change amounts of the main evaluation indexes such as the MTF peak value and the field curvature are smaller, and ensure the performance stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The specification drawings forming a part of the present application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It shows the dimension marking diagram of the optical imaging system of an optional embodiment of the present invention;

[0026] Figure 2 It shows the structural schematic diagram of the optical imaging system of Embodiment 1-1 of the present invention;

[0027] Figure 3 It shows the structural schematic diagram of the optical imaging system of Embodiment 1-2 of the present invention;

[0028] Figure 4 It shows the structural schematic diagram of the optical imaging system of Embodiment 1-3 of the present invention;

[0029] Figure 5 It shows the astigmatism curve of the optical imaging system of Embodiment 1 of the present invention;

[0030] Figure 6 It shows the longitudinal chromatic aberration curve of the optical imaging system of Embodiment 1 of the present invention;

[0031] Figure 7 It shows the structural schematic diagram of the optical imaging system of Embodiment 2-1 of the present invention;

[0032] Figure 8 Shows a schematic structural diagram of the optical imaging system of Embodiment 2-2 of the present invention;

[0033] Figure 9 Shows a schematic structural diagram of the optical imaging system of Embodiment 2-3 of the present invention;

[0034] Figure 10 Shows the astigmatism curve of the optical imaging system of Embodiment 2 of the present invention;

[0035] Figure 11 Shows the longitudinal chromatic aberration curve of the optical imaging system of Embodiment 2 of the present invention;

[0036] Figure 12 Shows a schematic structural diagram of the optical imaging system of Embodiment 3-1 of the present invention;

[0037] Figure 13 Shows a schematic structural diagram of the optical imaging system of Embodiment 3-2 of the present invention;

[0038] Figure 14 Shows a schematic structural diagram of the optical imaging system of Embodiment 3-3 of the present invention;

[0039] Figure 15 Shows the astigmatism curve of the optical imaging system of Embodiment 3 of the present invention;

[0040] Figure 16 Shows the longitudinal chromatic aberration curve of the optical imaging system of Embodiment 3 of the present invention;

[0041] Figure 17 Shows the field curvature change curve of the fifth lens when the optical imaging system of an alternative embodiment of the present application satisfies that the central thickness of the fifth lens is minimized, FOV = 116.06°, d4m / (T45 + CP4) = 45.55, and EP45 / CT5 = 5.07;

[0042] Figure 18 Shows the MTF peak change curve of the fifth lens when the optical imaging system of an alternative embodiment of the present application satisfies that the central thickness of the fifth lens is minimized, FOV = 116.06°, d4m / (T45 + CP4) = 45.55, and EP45 / CT5 = 5.07;

[0043] Figure 19 Shows the field curvature change curve of the fifth lens when the optical imaging system of Comparative Example 1 satisfies that the central thickness of the fifth lens is minimized, FOV = 116.06°, d4m / (T45 + CP4) = 45.55, and EP45 / CT5 = 1.00;

[0044] Figure 20Shows the MTF peak change curve of the fifth lens when the optical imaging system of Comparative Example 1 satisfies that the central thickness of the fifth lens is the smallest, FOV = 116.06°, d4m / (T45+CP4) = 45.55, and EP45 / CT5 = 1.00;

[0045] Figure 21 Shows the field curvature change curve of the fifth lens when the optical imaging system of Comparative Example 2 satisfies that the central thickness of the fifth lens is the smallest, FOV = 116.06°, d4m / (T45+CP4) = 45.55, and EP45 / CT5 = 9.00;

[0046] Figure 22 Shows the MTF peak change curve of the fifth lens when the optical imaging system of Comparative Example 2 satisfies that the central thickness of the fifth lens is the smallest, FOV = 116.06°, d4m / (T45+CP4) = 45.55, and EP45 / CT5 = 9.00.

[0047] Among them, the above-mentioned drawings include the following reference numerals:

[0048] P0, lens barrel; E1, first lens; S1, object side of the first lens; S2, image side of the first lens; E2, second lens; S3, object side of the second lens; S4, image side of the second lens; E3, third lens; S5, object side of the third lens; S6, image side of the third lens; E4, fourth lens; S7, object side of the fourth lens; S8, image side of the fourth lens; E5, fifth lens; S9, object side of the fifth lens; S10, image side of the fifth lens; E6, sixth lens; S11, object side of the sixth lens; S12, image side of the sixth lens; P1, first spacer element; P2, second spacer element; P3, third spacer element; P3b, third auxiliary spacer element; P4, fourth spacer element; P5, fifth spacer element. Detailed implementation manners

[0049] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0050] It should be pointed out that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0051] In the present invention, unless otherwise specified, the orientation terms such as "upper, lower, top, bottom" generally refer to the directions shown in the drawings or the vertical, perpendicular or gravitational directions of the components themselves; similarly, for the convenience of understanding and description, "inner, outer" refer to the inner and outer of the contours of the components themselves, but the above orientation terms are not used to limit the present invention.

[0052] It should be noted that in this specification, the expressions such as 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 teachings of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0053] In the drawings, for the convenience of illustration, the thickness, size and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0054] 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 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 and negative of the R value (R refers to the radius of curvature of 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 as an example, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; taking the image side as an example, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface.

[0055] In the present application, the object side refers to the side of the optical imaging system facing the object to be photographed (not shown in the figure), and the image side refers to the side of the optical imaging system facing the imaging surface (not shown in the figure). Hereinafter, the object side surface of the lens refers to the surface on the side of the lens facing the object to be photographed (not shown in the figure), and the image side surface of the lens refers to the surface on the side of the lens facing the imaging surface (not shown in the figure). In the structural schematic diagram shown in the present application, the left side is the object side and the right side is the image side.

[0056] In order to solve the problems in the prior art that the six-piece optical imaging system has a relatively large controlled field of view and a relatively small thickness of the end lens, resulting in a relatively large change in the surface shape of the end lens during the reliability verification process, and further resulting in a relatively large change in the MTF peak value and field curvature of the end lens, the present invention provides an optical imaging.

[0057] Such as Figures 1 to 18As shown, in an alternative embodiment of the present application, the optical imaging system includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group consists of six lenses. The six 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 positive optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power. Among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system. 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, and 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. The maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°. The inner diameter d4m of the image side surface of the fourth spacer element, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the maximum axial thickness CP4 of the fourth spacer element satisfy: 31.10 < d4m / (T45 + CP4) < 47.15. The central thickness CT5 of the fifth lens on the optical axis and the spacer distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: 4.00 < EP45 / CT5 < 5.78.

[0058] The optical imaging system of the present application is composed of a lens barrel and six lenses and multiple spacer elements disposed in the lens barrel. By setting the first lens to have a negative optical power, the second lens to have a positive optical power, the third lens to have a positive optical power, the fourth lens to have a positive optical power, the fifth lens to have a negative optical power, and the sixth lens to have a positive optical power, by reasonably constraining the positive and negative of the optical powers of each lens, and at the same time setting the central thickness of the fifth lens to be the smallest, and constraining 116.00° < FOV < 146.30°, however, when the FOV is relatively large and the thickness design of the fifth lens is relatively thin, it is easy to cause a large change in the surface shape of the fifth lens during the reliability verification, and further cause a large change in the MTF peak value and the field curvature of the fifth lens, affecting the stability of the overall performance. Therefore, by constraining 31.10 < d4m / (T45 + CP4) < 47.15 and 4.00 < EP45 / CT5 < 5.78, the overall structural reliability of the fifth lens can be guaranteed, ensuring that during the reliability test, the internal stress level distribution of the optical imaging system is more uniform, the deformation amount of the fifth lens is smaller, so as to ensure that the change amounts of the main evaluation indexes such as the MTF peak value and the field curvature are smaller, and the performance stability is guaranteed.

[0059] 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 the image-side surface portion of the first lens, a second spacer element disposed between the second lens and the third lens and in contact with the image-side surface portion of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side surface portion of the third lens. Among the first spacer element, the second spacer element, the third spacer element, the fourth spacer element, and the fifth spacer element, the third spacer element has the largest maximum axial thickness on the optical axis. The distance between the effective diameter edge positions of the third lens and the fourth lens on the optical axis is relatively large. By increasing the maximum axial thickness of the third spacer element, the thickness of the edge mechanism flange surface between the second lens and the third lens can be thinned, so that the two lenses before and after the third spacer element have a thickness ratio more favorable for processing and forming.

[0060] In addition, referring to Table 1 below and Figures 17 to 22 as shown, on the premise that the optical imaging system satisfies 116.00° < FOV < 146.30° and the central thickness of the fifth lens is the smallest, for example: FOV = 116.06°. Figure 17 and Figure 18 respectively show the field curvature change curve and the MTF peak change curve of the fifth lens when the optical imaging system of an alternative embodiment of the present application satisfies d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 5.07. Figure 19 and Figure 20 respectively show the field curvature change curve and the MTF peak change curve of the fifth lens when the optical imaging system of Comparative Example 1 satisfies d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 1.00. Figure 21 and Figure 22 respectively show the field curvature change curve and the MTF peak change curve of the fifth lens when the optical imaging system of Comparative Example 2 satisfies d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 9.00. Among them, the horizontal axis of the field curvature change curve represents the image height, and the vertical axis represents the change amount. The two curves are the field curvature change curves in the S direction and the M direction respectively; the horizontal axis of the MTF peak change curve represents the image height, and the vertical axis represents the change amount. The two curves are the MTF peak change curves in the S direction and the M direction respectively.

[0061] By Figures 17 to 22It can be known that when d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 5.07 are satisfied, the field curvature variation and MTF peak variation of the fifth lens at different image heights are both small, showing better performance. When d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 1.00 are satisfied, the MTF peak variation of the fifth lens at different image heights is large. When d4m / (T45 + CP4) = 45.55 and EP45 / CT5 = 9.00 are satisfied, both the field curvature variation and MTF peak variation of the fifth lens at different image heights are large. Thus, it can be seen that when 116.00° < FOV < 146.30° and the central thickness of the fifth lens is the smallest, and d4m / (T45 + CP4) is controlled within the range of 31.10 to 47.15, and EP45 / CT5 is controlled within the range of 4.00 to 5.78, the field curvature variation and MTF peak variation of the fifth lens are both the smallest, showing better performance. Therefore, in this application, by restricting 31.10 < d4m / (T45 + CP4) < 47.15 and 4.00 < EP45 / CT5 < 5.78, the overall structural reliability of the fifth lens is ensured. When dealing with the reliability test, the deformation of the fifth lens is smaller, so that the variation of the main evaluation indexes such as MTF peak and field curvature is smaller, the failure risk is lower, and the performance stability is ensured.

[0062] Table 1

[0063] This application Comparative Example 1 Comparative Example 2 Conditional formula EP45 / CT5 = 5.07 EP45 / CT5 = 1.00 EP45 / CT5 = 9.00

[0064] In this embodiment, the inner diameter d0m of the image-side end face of the lens barrel and the entrance pupil diameter EPD of the optical imaging system satisfy: 4.39 < d0m / EPD < 7.38. By controlling the inner diameter of the image-side end face of the lens barrel and the entrance pupil diameter of the optical imaging system, it can be ensured that the imaging light is not blocked by the lens barrel when exiting, and all the light is incident on the imaging surface, avoiding light loss, which is beneficial to controlling parameters such as the optical main value RI CRA and FOV without being affected, and ensuring the optical performance.

[0065] In this embodiment, the effective focal length f5 of the fifth lens and the axial distance EP45 between the fourth spacer element and the fifth spacer element satisfy: -2.77 < f5 / EP45 < -1.36. Through this condition, the effective focal length of the fifth lens can be controlled, the overall surface shape and structural uniformity of the fifth lens can be effectively controlled, the trend of the effective light can be controlled, which is beneficial to the stability of the system main value parameters; at the same time, by controlling the axial distance between the fourth spacer element and the fifth spacer element, that is, the edge thickness of the fifth lens, the sagittal height value of the fifth lens can be controlled, which is beneficial to the overall processing feasibility of the fifth lens.

[0066] In this embodiment, the following conditions are satisfied among the inner diameter d5m of the image side surface of the fifth spacer element, the outer diameter D5m of the image side surface of the fifth spacer element, and the central thickness CT6 of the sixth lens on the optical axis: 3.14 < (D5m - d5m) / CT6 < 4.95. By controlling the outer diameter and inner diameter of the image side surface of the fifth spacer element, it is beneficial for the fifth spacer element to block the stray light rays reflected inside the structure of the fifth lens and the stray light rays at the edge of the fifth lens, preventing the stray light rays from entering the sixth lens, which is beneficial for improving the stray light; by controlling the central thickness of the sixth lens, the overall wall thickness uniformity of the sixth lens can be effectively controlled, which is beneficial for the mold processing and injection molding of the sixth lens.

[0067] In this embodiment, the following conditions are satisfied among the outer diameter D5m of the image side surface of the fifth spacer element and the effective focal length f6 of the sixth lens: 2.09 < D5m / f6 < 3.68; the following conditions are satisfied among the inner diameter d5m of the image side surface of the fifth spacer element and the curvature radius R11 of the object side surface of the sixth lens: 1.69 < d5m / R11 < 2.35. By controlling the effective focal length of the sixth lens and the curvature radius of the object side surface, the overall shape of the sixth lens can be controlled, which is beneficial for the feasibility of the processing and molding of the sixth lens; by controlling the outer diameter and inner diameter of the image side surface of the fifth spacer element, it is ensured that the fifth spacer element can block the stray light transmitted through the edge of the sixth lens, which is beneficial for improving the picture quality. At the same time, the control of the ratio of the outer diameter to the inner diameter can limit the outer diameter sizes of the fifth lens and the sixth lens, reduce the misalignment amount, and is beneficial for improving the assembly stability.

[0068] In this embodiment, the following conditions are satisfied among the air gap T56 between the fifth lens and the sixth lens on the optical axis and the maximum axial thickness CP5 of the fifth spacer element: 10.50 < T56 / CP5 < 17.09. By controlling the axial thickness of the fifth spacer element and the air gap between the fifth lens and the sixth lens on the optical axis, the curvature size of the object side surface of the fifth lens can be controlled, which is beneficial for the transmission and refraction of light rays.

[0069] In this embodiment, the following conditions are satisfied among the central thickness CT4 of the fourth lens on the optical axis and the spacing distance EP34 between the third spacer element and the fourth spacer element on the optical axis: 1.45 < CT4 / EP34 < 3.25. Through this conditional expression, the spacing distance between the third spacer element and the fourth spacer element on the optical axis can be controlled, the edge thickness of the fourth lens can be controlled, which is beneficial for the processing and molding of the fourth lens; by controlling the central thickness of the fourth lens, the ratio of the thickness to the thinness of the fourth lens can be controlled within a suitable range, reducing the risk of the formed appearance joint line and stray light, which is beneficial for improving the appearance and imaging quality.

[0070] In this embodiment, the following condition is satisfied between the maximum axial thickness CP3 of the third spacer element and the axial distance SAG41 between the intersection of the object side surface of the fourth lens and the optical axis and the effective radius vertex of the object side surface of the first lens: 1.50 < CP3 / SAG41 < 2.60. By constraining this relationship, the on-axis height of the first several lenses can be controlled, and further the optical total length of the entire optical imaging system can be controlled, which is conducive to controlling the axial height of the optical imaging system within a suitable range. In addition, controlling the thickness of the third spacer element can adjust the thickness of the edge flanges of other lenses, which is beneficial to the overall assembly stability of the optical imaging system.

[0071] In this embodiment, the following condition is satisfied between the central thickness CT3 of the third lens on the optical axis, the effective focal length f3 of the third lens, and the maximum axial thickness CP3 of the third spacer element: 2.30 < f3 / (CT3 + CP3) < 6.15. Through this condition, it is beneficial to control the effective focal length, central thickness of the third lens, and the thickness of the third spacer element within a reasonable range, and the overall surface shape and structural dimensions of the third lens can be controlled, which is conducive to the molding filling of the third lens and ensures that the PV value and AS value are within a small range.

[0072] In this embodiment, the following condition is satisfied between the inner diameter d2m of the image side surface of the second spacer element and the central thickness CT3 of the third lens on the optical axis: 2.02 < d2m / CT3 < 2.83. By constraining this conditional formula, the inner diameter of the image side surface of the second spacer element is controlled to ensure that the second spacer element can block the stray light reflected by the second lens, and at the same time prevent other light rays from entering the third lens to generate new stray light; controlling the central thickness of the third lens helps to ensure the thickness uniformity of the third lens and control the third lens within a reasonable thickness ratio range.

[0073] In this embodiment, the following conditions are satisfied between the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens: 1.01 < R5 / R6 < 2.23; the following condition is satisfied between the inner diameter d3s of the object side surface of the third spacer element and the curvature radius R6 of the image side surface of the third lens: -2.75 < d3s / R6 < -1.26. By controlling this conditional formula, the curvature radius and ratio of the third lens are controlled, which can improve the imaging defect problem caused by spherical aberration. At the same time, by controlling the inner diameter of the object side surface of the third spacer element, it is ensured that the third spacer element can block the stray light reflected by the edge mechanism position of the third lens and the ineffective light rays at the effective diameter edge, reducing the stray light risk.

[0074] In this embodiment, the following conditions are satisfied between the inner diameter d3s of the object side surface of the third spacer element and the inner diameter d2s of the object side surface of the second spacer element: 1.21 < d3s / d2s < 2.30; the following condition is satisfied between the inner diameter d2s of the object side surface of the second spacer element and the air gap T23 between the second lens and the third lens on the optical axis: 6.92 < d2s / T23 < 9.93. By controlling the inner diameters of the object side surfaces of the second spacer element and the third spacer element, the marginal rays of the optical imaging system can be constrained to ensure the main values of the optical RI and fno. In addition, the front-end stray light can be blocked. At the same time, by controlling the air gap between the second lens and the third lens on the optical axis, the transmission stability of the central rays between the second lens and the third lens can be ensured, which is beneficial to ensuring the stability of the optical main values.

[0075] In this embodiment, the following condition is satisfied between the air gap T12 between the first lens and the second lens on the optical axis and the interval distance EP12 between the first spacer element and the second spacer element on the optical axis: 1.29 < T12 / EP12 < 2.22. By controlling this condition and the axial distance between the first spacer element and the second spacer element, the symmetry of the overall structure of the second lens can be controlled, and the risk of molding AS can be reduced. At the same time, by controlling the air gap between the first lens and the second lens on the optical axis, the distribution symmetry of the light rays can be adjusted, which is beneficial to improving the MTF peak value.

[0076] In this embodiment, the spacer element group further includes a third auxiliary spacer element disposed between the third lens and the fourth lens. The third auxiliary spacer element is in partial contact with the image side surface of the third spacer element. The following condition is satisfied between the combined focal length f34 of the third lens and the fourth lens, the maximum axial thickness CP3 of the third spacer element, and the maximum axial thickness CP3b of the third auxiliary spacer element: 1.50 < f34 / (CP3 + CP3b) < 2.50. By controlling the combined focal length of the third lens and the fourth lens, the trend and direction of the light rays between the second lens and the third lens can be controlled, and the sensitivity of the third lens and the fourth lens can be reduced. At the same time, the lens positions and surface shapes before and after the third lens and the fourth lens can be controlled and adjusted, which is beneficial to the symmetry of the overall structure of the optical imaging system. By controlling the thicknesses of the third spacer element and the third auxiliary spacer element, it is beneficial to configure the distance and size between the third lens and the fourth lens, and is conducive to further miniaturizing the axial thickness and volume of the optical imaging system.

[0077] In this embodiment, the object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is convex; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is concave; the object side surface of the sixth lens is convex, and the image side surface is concave. By reasonably restricting the surface types of the lenses, it is beneficial to the matching of the surface type and the optical power, further ensuring the requirements of the surface type matching the large field of view angle. At the same time, the light path can be planned to ensure a smooth transition of light, which is beneficial to balancing the front and rear aberrations, improving distortion, and ensuring the imaging quality.

[0078] Optionally, the optical imaging system 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 types of the lenses can be appropriately adjusted according to the built-in surface types of the software and / or tools used.

[0079] In addition, in another optional embodiment of the present application, an optical imaging system 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 six lenses. The six lenses are, in order from the object side to the image side, a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with positive optical power; the object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is convex; the object side surface of the third lens is concave, and the image side surface is convex; the object side surface of the fourth lens is convex, and the image side surface is convex; the object side surface of the fifth lens is concave; the object side surface of the sixth lens is convex, and the image side surface is concave; among them, among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system; 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, and 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; the maximum field of view angle FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°; the inner diameter d4m of the image side surface of the fourth spacer element, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the maximum axial thickness CP4 of the fourth spacer element satisfy: 31.10 < d4m / (T45 + CP4) < 47.15; the effective focal length f5 of the fifth lens and the interval distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: -2.77 < f5 / EP45 < -1.36.

[0080] The optical imaging system of the present application consists of a lens barrel, six lenses and multiple spacer elements arranged in the lens barrel. By setting the first lens to have a negative focal power, the second lens to have a positive focal power, the third lens to have a positive focal power, the fourth lens to have a positive focal power, the fifth lens to have a negative focal power, and the sixth lens to have a positive focal power, and by reasonably constraining the positive and negative of the focal powers and the surface shapes of each lens, while setting the central thickness of the fifth lens to be the smallest, and constraining 116.00° < FOV < 146.30°, however, when the FOV is relatively large and the thickness design of the fifth lens is relatively thin, it is easy to cause a relatively large change in the surface shape of the fifth lens during the reliability verification, and further lead to relatively large changes in the MTF peak value and the field curvature of the fifth lens, affecting the stability of the overall performance. Therefore, in the present application, by constraining 31.10 < d4m / (T45 + CP4) < 47.15 and -2.77 < f5 / EP45 < -1.36, the overall structural reliability of the fifth lens can be ensured, the effective focal length of the fifth lens can be controlled, the overall surface shape and the uniformity of the structure of the fifth lens can be effectively controlled, the trend of the effective light rays can be controlled, which is beneficial to the stability of the main value parameters of the system; at the same time, by controlling the distance between the fourth spacer element and the fifth spacer element on the optical axis, that is, the edge thickness of the fifth lens, the sag value of the fifth lens can be controlled, which is beneficial to the overall processing feasibility of the fifth lens.

[0081] Certainly, other parametric formulas in the above embodiments may also be included in this embodiment, which will not be elaborated one by one here.

[0082] In addition, in another alternative embodiment of the present application, the optical imaging system includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six 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 positive optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power. The object side surface of the first lens is convex, and the image side surface is concave. The object side surface of the second lens is convex. The object side surface of the third lens is concave, and the image side surface is convex. The object side surface of the fourth lens is convex, and the image side surface is convex. The object side surface of the fifth lens is concave. The object side surface of the sixth lens is convex, and the image side surface is concave. Among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system. 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, and 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. The maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°. The effective focal length f5 of the fifth lens and the maximum axial thickness CP5 of the fifth spacer element satisfy: -110.30 < f5 / CP5 < -74.00. The inner diameter d4m of the image side surface of the fourth spacer element and the maximum axial thickness CP4 of the fourth spacer element satisfy: 39.25 < d4m / T45 < 68.80.

[0083] The optical imaging system of the present application is composed of a lens barrel and six lenses and multiple spacer elements disposed in the lens barrel. By setting the first lens to have a negative optical power, the second lens to have a positive optical power, the third lens to have a positive optical power, the fourth lens to have a positive optical power, the fifth lens to have a negative optical power, and the sixth lens to have a positive optical power, by reasonably restricting the positive and negative of the optical power and the surface type of each lens, and at the same time setting the central thickness of the fifth lens to be the smallest, and restricting 116.00° < FOV < 146.30°, but when the FOV is relatively large and the thickness design of the fifth lens is relatively thin, it is easy to cause a large change in the surface type of the fifth lens during reliability verification, and then cause a large change in the MTF peak value and the field curvature of the fifth lens, affecting the stability of the overall performance. Therefore, in the present application, by restricting -110.30 < f5 / CP5 < -74.00 and 39.25 < d4m / T45 < 68.80, the effective focal length of the fifth lens is controlled, which can effectively control the overall surface type and the uniformity of the structure of the fifth lens, and is beneficial to the stability of the main evaluation indexes such as the MTF peak value and the field curvature. At the same time, controlling CP5, d4m, and T45 is beneficial to the overall processing feasibility of the fifth lens and is beneficial to the forming of the fifth lens.

[0084] 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.

[0085] Optionally, the above optical imaging system may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0086] The optical imaging system in the present application may employ multiple lenses, such as the six lenses described above. In the present application, at least one of the lens surfaces of each lens is an aspherical surface. The characteristics of an aspherical lens are 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, it is possible to eliminate as much as possible the aberration that appears during imaging, thereby improving the imaging quality.

[0087] However, those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification. For example, although six lenses are described as an example in the embodiments, the optical imaging system is not limited to including six lenses. If necessary, the optical imaging system may also include other numbers of lenses.

[0088] Figure 1 A schematic diagram of the dimension marking of an optical imaging system of the present application is shown. Figure 1 Parameters such as d3s, d2s, d2m, d4m, d5m, D5m, d0m, CP3b, CP3, CP4, CP5, EP12, EP34, EP45 are marked in it to clearly and intuitively understand the meaning of the parameters. For the convenience of describing the optical imaging system and the surface type of specific lenses, these parameters will no longer be shown in the drawings when specific embodiments are described later.

[0089] The following further describes, with reference to the drawings, examples of the specific surface type and parameters of the optical imaging system applicable to the above embodiments.

[0090] It should be noted that in the following Example 1, there are three examples of Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3. In Example 2, there are three examples of Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3. In Example 3, there are three examples of Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3. And under the three examples in the same embodiment, the curvature radius, center thickness and other parameters of the first lens to the sixth lens of the optical imaging system, as well as the spacing distance and higher-order term coefficients between the lenses are the same, but the parameters such as the lens barrel, the thickness, inner diameter and outer diameter of the first spacer element to the fifth spacer element are different.

[0091] It should be noted that any one of the following Examples 1 to 3 is applicable to all embodiments of this application.

[0092] Example 1

[0093] As Figures 2 to 6 shown, an optical imaging system of Example 1 is described. Figure 2 FIG. shows a schematic structural diagram of the optical imaging system of Example 1-1. Figure 3 FIG. shows a schematic structural diagram of the optical imaging system of Example 1-2. Figure 4 FIG. shows a schematic structural diagram of the optical imaging system of Example 1-3.

[0094] As Figures 2 to 4 shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a third auxiliary spacer element P3b, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, and a sixth lens E6 that are sequentially arranged in the lens barrel P0 from the object side to the image side along the optical axis.

[0095] As Figure 2 shown, it is a schematic structural diagram of the optical imaging system of Example 1-1. In this example, the object side surface and the image side surface of the first spacer element P1 are respectively in partial 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 the image side surface of the second spacer element P2 are respectively in partial 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 the image side surface of the third spacer element P3 are respectively in partial contact with the image side surface S6 of the third lens and the object side surface of the third auxiliary spacer element P3b, and the image side surface of the third auxiliary spacer element P3b is in partial contact with the object side surface S7 of the fourth lens. The object side surface and the image side surface of the fourth spacer element P4 are respectively in partial 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 the image side surface of the fifth spacer element P5 are respectively in partial contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens.

[0096] As Figure 3 shown, it is a schematic structural diagram of the optical imaging system of Example 1-2. In this example, the abutting and contacting manner of each spacer element is the same as that of Example 1-1, and reference can be made to the relevant description in Example 1-1, which will not be elaborated here.

[0097] As Figure 4 shown, it is a schematic structural diagram of the optical imaging system of Example 1-3. In this example, the abutting and contacting manner of each spacer element is the same as that of Example 1-1, and reference can be made to the relevant description in Example 1-1, which will not be elaborated here.

[0098] In summary, the structural parameters of the optical imaging system in the first embodiment under Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3 are shown in Table 2 (unit: mm).

[0099] Table 2

[0100] Parameter / Example 1-1 1-2 1-3 d2s 2.544 2.516 2.562 d2m 2.544 2.516 2.562 d3s 4.665 4.725 4.752 d4m 2.841 2.828 2.828 d5m 2.980 3.042 3.073 D5m 7.026 7.068 7.216 d0m 7.224 7.320 7.420 EP12 0.669 0.665 0.675 CP3 0.813 0.883 1.013 EP34 0.483 0.411 0.361 CP4 0.016 0.017 0.018 EP45 1.002 1.073 1.122 CP5 0.020 0.021 0.022 CP3b 0.022 0.022 0.022

[0101] In the first embodiment, the object side S1 of the first lens is convex, and the image side S2 of the first lens is concave. The object side S3 of the second lens is convex, and the image side S4 of the second lens is concave. The object side S5 of the third lens is concave, and the image side S6 of the third lens is convex. The object side S7 of the fourth lens is convex, and the image side S8 of the fourth lens is convex. The object side S9 of the fifth lens is concave, and the image side S10 of the fifth lens is concave. The object side S11 of the sixth lens is convex, and the image side S12 of the sixth lens is concave.

[0102] In the first embodiment, the maximum field of view angle FOV of the optical imaging system is 138.114°, the entrance pupil diameter EPD of the optical imaging system is 1.170 mm, the effective focal length f of the optical imaging system is 1.400 mm, the effective focal length f1 of the first lens is -2.526 mm, the effective focal length f2 of the second lens is 9.756 mm, the effective focal length f3 of the third lens is 6.983 mm, the effective focal length f4 of the fourth lens is 2.290 mm, the effective focal length f5 of the fifth lens is -1.638 mm, the effective focal length f6 of the sixth lens is 2.160 mm, and the combined focal length f34 of the third lens and the fourth lens is 1.601 mm.

[0103] Table 3 shows the basic structural parameter table of the optical imaging system in the first embodiment, where the unit of the radius of curvature and the thickness / distance is mm. In the following table, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, and the aperture stop is located between the third lens E3 and the fourth lens E4. S13 and S14 (not shown in the figure) can be the object side and the image side of the filter or the object side and the image side of the protective glass.

[0104] Table 3

[0105]

[0106]

[0107] In the first embodiment, the object side and the image side of the first lens E1 to the sixth lens E6 are both aspherical surfaces, and the surface profiles of the aspherical lenses can be defined by, but not limited to, the following aspherical formula:

[0108]

[0109] Wherein, x is the sagitta, which is the distance from the vertex of the aspheric surface to the position along the optical axis at a height of h; c is the paraxial curvature of the aspheric surface, and c = 1 / R, that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 3 above; k is the conic constant; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 4 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 for each of the aspheric mirrors S1 - S12 in Example 1.

[0110] Table 4

[0111] Plane number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 1.1075E-02 -3.2349E-03 1.9236E-03 -8.7350E-04 2.1760E-04 -2.4486E-05 -5.0697E-07 3.7523E-07 -2.4454E-08 S2 5.3716E-02 -1.9092E-01 8.8590E-01 -2.0442E+00 2.7440E+00 -2.2073E+00 1.0494E+00 -2.7112E-01 2.9235E-02 S3 2.0718E-02 -1.3331E-01 1.5171E-01 -1.3861E-01 7.3642E-02 2.4676E-03 -2.5633E-02 1.2255E-02 -1.8859E-03 S4 -4.0748E-02 1.8710E-02 -2.0968E-01 5.0360E-01 -6.7235E-01 5.6029E-01 -2.8315E-01 7.8703E-02 -9.1874E-03 S5 2.1157E-02 -5.4230E-02 9.6798E-02 -3.4441E-01 7.2832E-01 -8.6586E-01 5.9326E-01 -2.1981E-01 3.4064E-02 S6 -6.1821E-02 2.2209E-01 -5.1719E-01 8.6800E-01 -9.8777E-01 7.4117E-01 -3.5032E-01 9.4351E-02 -1.1023E-02 S7 -9.5612E-02 1.3165E-01 -2.3968E-01 3.0704E-01 -2.5452E-01 1.3370E-01 -4.2945E-02 7.6675E-03 -5.8068E-04 S8 1.2849E-01 -6.3295E-01 1.1409E+00 -1.0349E+00 4.3279E-01 1.1414E-02 -8.7505E-02 3.2752E-02 -4.0426E-03 S9 4.4470E-01 -8.4725E-01 1.4634E+00 -1.6277E+00 1.1175E+00 -4.5370E-01 9.7503E-02 -7.2887E-03 -3.9184E-04 S10 -1.3334E-01 4.9260E-01 -7.8136E-01 7.2817E-01 -4.3056E-01 1.6056E-01 -3.4244E-02 3.0748E-03 3.1038E-05 S11 -3.2449E-01 5.4621E-01 -7.1914E-01 6.9740E-01 -4.7673E-01 2.2072E-01 -6.5507E-02 1.1224E-02 -8.4459E-04 S12 5.5562E-02 -4.6339E-02 1.0974E-01 -1.3605E-01 1.0285E-01 -4.9959E-02 1.4931E-02 -2.4482E-03 1.6250E-04

[0112] Figure 5 Shows the astigmatism curve of the optical imaging system of Example 1, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 6 Shows the longitudinal chromatic aberration curve of the optical imaging system of Example 1, which represents the deviation of different image heights on the imaging plane after light passes through the optical imaging system.

[0113] According to Figure 5 and Figure 6 it can be seen that the optical imaging system given in Example 1 can achieve good imaging quality.

[0114] Example 2

[0115] As Figures 7 to 11 shown, the optical imaging system of Example 2 is described. Figure 7 Shows the structural schematic diagram of the optical imaging system of Example 2 - 1, Figure 8 Shows the structural schematic diagram of the optical imaging system of Example 2 - 2, Figure 9 Shows the structural schematic diagram of the optical imaging system of Example 2 - 3.

[0116] As Figures 7 to 9 shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a third auxiliary spacer P3b, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, and a sixth lens E6 that are sequentially arranged in the lens barrel P0 from the object side to the image side along the optical axis.

[0117] As Figure 7As shown, it is a schematic structural diagram of the optical imaging system of Embodiment 2-1. In this example, the object side and the image side of the first spacer element P1 are in partial contact with the image side S2 of the first lens and the object side S3 of the second lens, respectively. The object side and the image side of the second spacer element P2 are in partial contact with the image side S4 of the second lens and the object side S5 of the third lens, respectively. The object side and the image side of the third spacer element P3 are in partial contact with the image side S6 of the third lens and the object side of the third auxiliary spacer element P3b, respectively, and the image side of the third auxiliary spacer element P3b is in partial contact with the object side S7 of the fourth lens. The object side and the image side of the fourth spacer element P4 are in partial contact with the image side S8 of the fourth lens and the object side S9 of the fifth lens, respectively. The object side and the image side of the fifth spacer element P5 are in partial contact with the image side S10 of the fifth lens and the object side S11 of the sixth lens, respectively.

[0118] As Figure 8 shown, it is a schematic structural diagram of the optical imaging system of Embodiment 2-2. In this example, the abutting and contacting manners of each spacer element are the same as those in Embodiment 2-1. For relevant descriptions, reference can be made to Embodiment 2-1, and details will not be elaborated here.

[0119] As Figure 9 shown, it is a schematic structural diagram of the optical imaging system of Embodiment 2-3. In this example, the abutting and contacting manners of each spacer element are the same as those in Embodiment 2-1. For relevant descriptions, reference can be made to Embodiment 2-1, and details will not be elaborated here.

[0120] In summary, the structural parameters of the optical imaging system in Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are as shown in Table 5 (unit: mm).

[0121] Table 5

[0122]

[0123]

[0124] In Embodiment 2, the object side S1 of the first lens is convex, and the image side S2 of the first lens is concave. The object side S3 of the second lens is convex, and the image side S4 of the second lens is concave. The object side S5 of the third lens is concave, and the image side S6 of the third lens is convex. The object side S7 of the fourth lens is convex, and the image side S8 of the fourth lens is convex. The object side S9 of the fifth lens is concave, and the image side S10 of the fifth lens is concave. The object side S11 of the sixth lens is convex, and the image side S12 of the sixth lens is concave.

[0125] In Embodiment 2, the maximum field of view angle FOV of the optical imaging system is 146.286°, the entrance pupil diameter EPD of the optical imaging system is 1.128 mm, the effective focal length f of the optical imaging system is 1.350 mm, the effective focal length f1 of the first lens is -2.522 mm, the effective focal length f2 of the second lens is 33.399 mm, the effective focal length f3 of the third lens is 4.811 mm, the effective focal length f4 of the fourth lens is 2.359 mm, the effective focal length f5 of the fifth lens is -1.691 mm, the effective focal length f6 of the sixth lens is 2.220 mm, and the combined focal length f34 of the third lens and the fourth lens is 1.531 mm.

[0126] Table 6 shows the basic structural parameter table of the optical imaging system in Embodiment 2. Among them, the units of the radius of curvature and the thickness / distance are both millimeters (mm). In the following table, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, and the aperture stop is located between the third lens E3 and the fourth lens E4. S13 and S14 (not shown in the figure) can be the object side of the filter and the image side of the filter or the object side of the protective glass and the image side of the protective glass.

[0127] Table 6

[0128]

[0129] The following Table 7 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 of the aspherical mirror surfaces S1 - S12 that can be used in Embodiment 2.

[0130] Table 7

[0131] Plane number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 1.0174E-02 7.3660E-04 -2.4657E-03 1.5090E-03 -5.3840E-04 1.1924E-04 -1.6152E-05 1.2267E-06 -3.9961E-08 S2 4.0341E-02 -3.9362E-02 2.6714E-01 -6.5359E-01 9.0237E-01 -7.3282E-01 3.4829E-01 -8.9146E-02 9.4075E-03 S3 1.1817E-01 -4.3386E-01 7.8600E-01 -1.0403E+00 9.3222E-01 -5.3193E-01 1.8222E-01 -3.3718E-02 2.5540E-03 S4 -5.0016E-02 2.8634E-02 -2.8382E-01 7.5550E-01 -1.1129E+00 1.0074E+00 -5.4501E-01 1.6057E-01 -1.9740E-02 S5 1.3984E-02 -3.5832E-02 1.9915E-02 -1.5094E-01 4.3861E-01 -6.0794E-01 4.6178E-01 -1.8459E-01 3.0201E-02 S6 -7.0063E-03 2.4025E-02 -5.6474E-03 -8.8513E-03 7.8463E-03 4.1583E-03 -8.8346E-03 4.5404E-03 -8.0181E-04 S7 -3.6860E-02 -4.1510E-02 1.3527E-01 -2.2700E-01 2.3888E-01 -1.5719E-01 6.2460E-02 -1.3701E-02 1.2742E-03 S8 1.7383E-01 -6.6342E-01 9.2272E-01 -4.2094E-01 -3.3084E-01 5.5035E-01 -3.1112E-01 8.3824E-02 -9.0144E-03 S9 4.4070E-01 -8.4630E-01 1.3721E+00 -1.4160E+00 9.0149E-01 -3.4177E-01 6.9139E-02 -4.8285E-03 -2.8665E-04 S10 -1.4808E-01 5.1677E-01 -7.9714E-01 7.3833E-01 -4.4392E-01 1.7066E-01 -3.7589E-02 3.4354E-03 4.6224E-05 S11 -3.0673E-01 5.0766E-01 -6.5290E-01 6.0977E-01 -3.9628E-01 1.7237E-01 -4.7618E-02 7.5623E-03 -5.2942E-04 S12 5.0531E-02 -4.5307E-02 1.2824E-01 -1.8479E-01 1.6665E-01 -9.7303E-02 3.5153E-02 -7.0690E-03 5.9768E-04

[0132] Figure 10 Shows the astigmatism curve of the optical imaging system in Embodiment 2, which represents the curvature of the meridional image plane and the curvature of the sagittal image plane. Figure 11 Shows the longitudinal chromatic aberration curve of the optical imaging system in Embodiment 2, which represents the deviation of different image heights of the light rays on the imaging plane after passing through the optical imaging system.

[0133] According to Figure 10 and Figure 11 it can be known that the optical imaging system given in Embodiment 2 can achieve good imaging quality.

[0134] Embodiment 3

[0135] As Figures 12 to 16 shown, the optical imaging system in Embodiment 3 is described. Figure 12 Shows the structural schematic diagram of the optical imaging system in Embodiment 3-1. Figure 13The schematic structural diagram of the optical imaging system of Embodiment 3-2 is shown. Figure 14 The schematic structural diagram of the optical imaging system of Embodiment 3-3 is shown.

[0136] As Figures 12 to 14 shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacer element P1, a second lens E2, a second spacer element P2, a third lens E3, a third spacer element P3, a third auxiliary spacer element P3b, a fourth lens E4, a fourth spacer element P4, a fifth lens E5, a fifth spacer element P5, and a sixth lens E6 that are sequentially arranged in the lens barrel P0 from the object side to the image side along the optical axis.

[0137] As Figure 12 shown, the schematic structural diagram of the optical imaging system of Embodiment 3-1 is shown. In this example, the object side surface and the image side surface of the first spacer element P1 are respectively in partial 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 the image side surface of the second spacer element P2 are respectively in partial 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 the image side surface of the third spacer element P3 are respectively in partial contact with the image side surface S6 of the third lens and the object side surface of the third auxiliary spacer element P3b, and the image side surface of the third auxiliary spacer element P3b is in partial contact with the object side surface S7 of the fourth lens. The object side surface and the image side surface of the fourth spacer element P4 are respectively in partial 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 the image side surface of the fifth spacer element P5 are respectively in partial contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens.

[0138] As Figure 13 shown, the schematic structural diagram of the optical imaging system of Embodiment 3-2 is shown. In this example, the abutting and contacting manner of each spacer element is the same as that in Embodiment 3-1, and reference can be made to the relevant description in Embodiment 3-1, which will not be elaborated here.

[0139] As Figure 14 shown, the schematic structural diagram of the optical imaging system of Embodiment 3-3 is shown. In this example, the abutting and contacting manner of each spacer element is the same as that in Embodiment 3-1, and reference can be made to the relevant description in Embodiment 3-1, which will not be elaborated here.

[0140] In summary, the structural parameters of the optical imaging system in Embodiment 3 under Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3 are as shown in Table 8 (unit: mm).

[0141] Table 8

[0142] Parameter / Example 3-1 3-2 3-3 d2s 2.670 2.678 2.685 d2m 2.670 2.678 2.685 d3s 3.352 3.403 3.742 d4m 3.063 3.093 3.052 d5m 2.893 2.901 2.906 D5m 6.054 6.444 7.085 d0m 6.671 6.986 7.628 EP12 0.685 0.684 0.683 CP3 1.050 1.031 0.748 EP34 0.450 0.305 0.549 CP4 0.020 0.021 0.022 EP45 0.812 1.024 1.014 CP5 0.020 0.021 0.022 CP3b 0.022 0.022 0.022

[0143] In Embodiment 3, the object side S1 of the first lens is convex, and the image side S2 of the first lens is concave. The object side S3 of the second lens is convex, and the image side S4 of the second lens is convex. The object side S5 of the third lens is concave, and the image side S6 of the third lens is convex. The object side S7 of the fourth lens is convex, and the image side S8 of the fourth lens is convex. The object side S9 of the fifth lens is concave, and the image side S10 of the fifth lens is convex. The object side S11 of the sixth lens is convex, and the image side S12 of the sixth lens is concave.

[0144] In Embodiment 3, the maximum field of view angle FOV of the optical imaging system is 116.062°, the entrance pupil diameter EPD of the optical imaging system is 1.506 mm, the effective focal length f of the optical imaging system is 1.800 mm, the effective focal length f1 of the first lens is -3.260 mm, the effective focal length f2 of the second lens is 7.240 mm, the effective focal length f3 of the third lens is 10.445 mm, the effective focal length f4 of the fourth lens is 2.445 mm, the effective focal length f5 of the fifth lens is -2.205 mm, the effective focal length f6 of the sixth lens is 2.824 mm, and the combined focal length f34 of the third lens and the fourth lens is 1.807 mm.

[0145] Table 9 shows the basic structural parameter table of the optical imaging system in Embodiment 3. Among them, the unit of the radius of curvature and the thickness / distance is millimeter (mm). In the following table, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, and the aperture stop is located between the third lens E3 and the fourth lens E4. S13 and S14 (not shown in the figure) can be the object side of the filter and the image side of the filter or the object side of the protective glass and the image side of the protective glass.

[0146] Table 9

[0147]

[0148]

[0149] The following Table 10 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20 for each aspherical mirror surface S1 - S12 in Embodiment 3.

[0150] Table 10

[0151] Plane number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -7.9081E-02 2.3288E-02 -4.5015E-03 6.7853E-04 -9.1198E-05 8.9040E-06 -3.5618E-07 -4.7366E-09 0.0000E+00 S2 -7.5054E-02 4.5072E-02 -3.1871E-02 3.7049E-02 -3.5684E-02 2.5061E-02 -1.1235E-02 2.9174E-03 -3.5194E-04 S3 -1.2030E-02 -7.6059E-03 -1.6520E-02 1.7981E-02 -1.2571E-02 4.5277E-03 -5.2923E-04 -6.4713E-06 0.0000E+00 S4 -1.2670E-03 -1.3405E-02 -2.5283E-03 -1.0102E-03 3.2016E-03 -1.2244E-03 2.7077E-04 4.7083E-06 0.0000E+00 S5 -3.4169E-03 1.5755E-03 -1.8658E-02 1.9673E-02 -1.4085E-02 6.7098E-03 -1.3943E-03 0.0000E+00 0.0000E+00 S6 -8.3335E-03 9.9377E-03 -5.1819E-03 -7.2531E-05 1.3677E-03 -5.9031E-04 7.6339E-05 0.0000E+00 0.0000E+00 S7 -2.2444E-02 1.2699E-02 -4.8194E-04 -4.3205E-03 2.9391E-03 -7.7928E-04 3.7261E-05 3.3480E-06 0.0000E+00 S8 -1.4628E-02 -2.2729E-02 4.5028E-02 -3.4461E-02 1.4718E-02 -3.2271E-03 2.1300E-04 1.4217E-05 0.0000E+00 S9 1.9072E-01 -1.6350E-01 1.2199E-01 -6.3688E-02 2.1753E-02 -3.9677E-03 2.6630E-04 0.0000E+00 0.0000E+00 S10 4.6446E-02 5.9018E-03 -5.7464E-02 6.5525E-02 -3.8181E-02 1.1969E-02 -1.5591E-03 -4.7073E-06 0.0000E+00 S11 -1.0467E-01 7.6706E-02 -6.6961E-02 4.0746E-02 -1.7409E-02 4.3646E-03 -4.9510E-04 0.0000E+00 0.0000E+00 S12 3.5438E-02 -1.0707E-02 1.9127E-02 -1.5002E-02 5.6435E-03 -7.0011E-04 -2.2299E-05 -6.2512E-06 0.0000E+00

[0152] Figure 15 Shows the astigmatism curve of the optical imaging system in Embodiment 3, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 16The magnification chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of different image heights on the imaging surface after light passes through the optical imaging system.

[0153] According to Figure 15 and Figure 16 it can be known that the optical imaging system given in Embodiment 3 can achieve good imaging quality.

[0154] In summary, Embodiments 1 to 3 respectively satisfy the relationships shown in Table 11.

[0155] Table 11

[0156] Conditional formula / Example 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 EP45 / CT5 4.89 5.23 5.47 4.14 5.06 5.73 4.06 5.12 5.07 d4m / (T45 + CP4) 32.28 31.78 31.42 31.80 31.57 31.22 47.12 46.86 45.55 d0m / EPD 6.17 6.26 6.34 6.55 6.95 7.33 4.43 4.64 5.07 f5 / EP45 -1.63 -1.53 -1.46 -1.94 -1.59 -1.41 -2.72 -2.15 -2.17 (D5m - d5m) / CT6 4.01 3.99 4.11 4.18 4.54 4.90 3.19 3.57 4.21 D5m / f6 3.25 3.27 3.34 3.24 3.44 3.63 2.14 2.28 2.51 d5m / R11 2.23 2.27 2.30 2.08 2.14 2.19 1.64 1.65 1.65 T56 / CP5 11.60 11.05 10.55 12.25 11.67 11.14 17.05 16.24 15.50 CT4 / EP34 1.94 2.28 2.60 1.49 2.99 2.22 2.16 3.20 1.77 CP3 / SAG41 2.05 2.22 2.55 1.55 2.29 1.89 2.42 2.38 1.73 f3 / (CT3 + CP3) 3.51 3.39 3.19 2.73 2.35 2.54 5.18 5.23 6.09 R5 / R6 1.47 1.47 1.47 2.18 2.18 2.18 1.06 1.06 1.06 d3s / R6 -2.23 -2.26 -2.27 -2.33 -2.60 -2.71 -1.31 -1.33 -1.46 d2m / CT3 2.17 2.14 2.18 2.13 2.11 2.07 2.76 2.77 2.78 d3s / d2s 1.83 1.88 1.85 1.89 2.12 2.25 1.26 1.27 1.39 d2s / T23 7.88 7.79 7.93 7.18 7.12 6.97 9.82 9.85 9.88 T12 / EP12 1.93 1.95 1.92 2.17 1.92 1.77 1.34 1.34 1.34 f34 / (CP3 + CP3b) 1.92 1.77 1.55 2.45 1.68 2.03 1.69 1.72 2.35 f5 / CP5 -81.90 -78.00 -74.45 -84.55 -80.52 -76.86 -110.25 -105.00 -100.23 d4m / T45 39.46 39.28 39.28 41.01 41.17 41.17 68.07 68.73 67.82

[0157] Table 12 shows data such as the effective focal lengths of the lenses of the optical imaging systems of Embodiments 1 to 3.

[0158] Table 12

[0159] Basic data / Example One Two Three FOV (°) 138.11 146.29 116.06 EPD (mm) 1.170 1.128 1.506 f (mm) 1.400 1.350 1.800 f1 (mm) -2.526 -2.522 -3.260 f2 (mm) 9.756 33.399 7.240 f3 (mm) 6.983 4.811 10.445 f4 (mm) 2.290 2.359 2.445 f5 (mm) -1.638 -1.691 -2.205 f6 (mm) 2.160 2.220 2.824 f34 (mm) 1.601 1.531 1.807 SAG41 (mm) 0.397 0.389 0.433

[0160] This application also provides an imaging device, and its electronic photosensitive element can be a charge-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 on a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0161] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0162] 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 this 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 "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0163] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application described herein can be implemented in an order other than those illustrated or described herein.

[0164] The above are only the preferred embodiments of the present invention and are 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 within the protection scope of the present invention.

Claims

1. An optical imaging system, 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 six lenses. The six 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 positive optical power, a third lens with a positive optical power, a fourth lens with a positive optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power; among them, among the first lens to the sixth lens, the fifth lens has the smallest central thickness on the optical axis of the optical imaging system. 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, and 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. The maximum field of view FOV of the optical imaging system satisfies: 116.00° < FOV < 146.30°. The inner diameter d4m of the image side surface of the fourth spacer element, the air gap T45 between the fourth lens and the fifth lens on the optical axis, and the maximum axial thickness CP4 of the fourth spacer element satisfy: 31.10 < d4m / (T45 + CP4) < 47.

15. The central thickness CT5 of the fifth lens on the optical axis and the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: 4.00 < EP45 / CT5 < 5.

78.

2. The optical imaging system according to claim 1, wherein The inner diameter d0m of the image side end face of the lens barrel and the entrance pupil diameter EPD of the optical imaging system satisfy: 4.39 < d0m / EPD < 7.

38.

3. The optical imaging system according to claim 1, wherein The effective focal length f5 of the fifth lens and the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis satisfy: -2.77 < f5 / EP45 < -1.

36.

4. The optical imaging system according to claim 1, characterized in that, The inner diameter d5m of the image side surface of the fifth spacer element, the outer diameter D5m of the image side surface of the fifth spacer element, and the central thickness CT6 of the sixth lens on the optical axis satisfy: 3.14 < (D5m - d5m) / CT6 < 4.

95.

5. The optical imaging system according to claim 1, wherein The outer diameter D5m of the image side surface of the fifth spacer element and the effective focal length f6 of the sixth lens satisfy: 2.09 < D5m / f6 < 3.68; the inner diameter d5m of the image side surface of the fifth spacer element and the curvature radius R11 of the object side surface of the sixth lens satisfy: 1.69 < d5m / R11 < 2.

35.

6. The optical imaging system according to claim 1, characterized in that, The air gap T56 between the fifth lens and the sixth lens on the optical axis and the maximum axial thickness CP5 of the fifth spacer element satisfy: 10.50 < T56 / CP5 < 17.

09.

7. The optical imaging system according to claim 1, wherein The spacer element group further includes a third spacer element placed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens. The central thickness CT4 of the fourth lens on the optical axis and the distance EP34 between the third spacer element and the fourth spacer element on the optical axis satisfy: 1.45 < CT4 / EP34 < 3.

25.

8. The optical imaging system according to claim 1, wherein The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The maximum axial thickness CP3 of the third spacer element and the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis and the vertex of the effective radius of the object-side surface of the first lens satisfy: 1.50 < CP3 / SAG41 < 2.

60.

9. The optical imaging system according to claim 1, characterized in that, The spacer element group further includes a third spacer element disposed between the third lens and the fourth lens and in contact with the image-side portion of the third lens. The center thickness CT3 of the third lens on the optical axis, the effective focal length f3 of the third lens, and the maximum axial thickness CP3 of the third spacer element satisfy: 2.30 < f3 / (CT3 + CP3) < 6.

15.

10. The optical imaging system according to claim 1, wherein The spacer element group further includes a second spacer element disposed between the second lens and the third lens and in contact with the image-side portion of the second lens. The inner diameter d2m of the image-side surface of the second spacer element and the center thickness CT3 of the third lens on the optical axis satisfy: 2.02 < d2m / CT3 < 2.83.

Images