Optical image capturing system

Abstract

The utility model discloses an optical imaging system, which comprises a lens barrel, a lens group and a spacing element group, and is characterized in that the lens group comprises a first lens, a second lens, a third lens, a fourth lens and a sixth lens which are sequentially arranged from an object side to an image side along an optical axis, the effective focal lengths of the first lens, the second lens and the fifth lens are negative, and the effective focal lengths of the third lens, the fourth lens and the sixth lens are positive; the spacer element group includes a fourth spacer element located on the image side of the fourth lens and abutting against the image side surface portion of the fourth lens, and a fifth spacer element located on the image side of the fifth lens and abutting against the image side surface portion of the fifth lens. The distance EP45 between the fourth and fifth spacing elements on the optical axis, the air interval T56 between the fifth and sixth lenses on the optical axis, the outer diameter D4m of the image side surface of the fourth spacing element, the inner diameter d5s of the object side surface of the fifth spacing element and the effective focal length f5 of the fifth lens meet the following conditions: 2.5 lt; eP 45 / T56lt; 5.5, and-2lt; (D4m-d5s) / f5lt; and-0.5.

Description

Technical Field

[0001] This application relates to the field of optical elements, and more specifically, to an optical imaging system. Background Art

[0002] The wide-angle lens has the characteristics of a larger and wider field of view angle than ordinary lenses. With the development of technology, the application scenarios of wide-angle lenses have gradually expanded, and they are not only applied to mobile phone cameras but also used in vehicle-mounted lenses and UAV obstacle avoidance lenses to help vehicles and UAVs better perceive the surrounding environment. On the premise of ensuring lens performance and manufacturability, the miniaturization of a single lens is beneficial for better layout and weight reduction in the whole machine, so it has gradually become the common goal pursued by lens manufacturers. Based on this direction, those skilled in the art expect to design a more compact six-piece optical system, which can ensure good optical performance and manufacturability while having the characteristics of miniaturization. Summary of the Utility Model

[0003] This application provides an optical imaging system, which may include a lens barrel and a lens group and a spacer element group accommodated in the lens barrel. Among them, the lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the optical axis; among them, the effective focal length values of the first lens, the second lens, and the fifth lens are less than zero; the effective focal length values of the third lens, the fourth lens, and the sixth lens are greater than zero; the spacer element group includes: a fourth spacer element, located on the image side of the fourth lens and partially abutting against the image side surface of the fourth lens; a fifth spacer element, located on the image side of the fifth lens and partially abutting against the image side surface of the fifth lens; and the optical imaging system satisfies: 2.5 < EP45 / T56 < 5.5 and -2 < (D4m - d5s) / f5 < -0.5, where EP45 is the distance between the fourth spacer element and the fifth spacer element on the optical axis, T56 is the air gap between the fifth lens and the sixth lens on the optical axis, D4m is the outer diameter of the image side surface of the fourth spacer element, d5s is the inner diameter of the object side surface of the fifth spacer element, and f5 is the effective focal length of the fifth lens.

[0004] In one embodiment, the combined focal length f56 of the fifth lens and the sixth lens, the maximum thickness CP5 of the fifth spacer element, and the central thickness CT6 of the sixth lens on the optical axis satisfy: -24 < f56 / T56 < -20 and 0 < CP5 / CT6 < 0.9.

[0005] In one embodiment, the outer diameter D5m of the image side surface of the fifth spacer element, the radius of curvature R11 of the object side surface of the sixth lens, the outer diameter D5s of the object side surface of the fifth spacer element, and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 1.8 < D5m / R11 < 3.3 and 0.5 < D5s / R10 < 1.8.

[0006] In one embodiment, the spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; the air gap T34 between the third lens and the fourth lens on the optical axis, the maximum thickness CP3 of the third spacer element, and the maximum thickness CP4 of the fourth spacer element satisfy: 3.3 < T34 / (CP3 + CP4) < 7.

[0007] In one embodiment, the radius of curvature R8 of the image side surface of the fourth lens, the radius of curvature R7 of the object side surface of the fourth lens, the inner diameter d4s of the object side surface of the fourth spacer element, the outer diameter D4m of the image side surface of the fourth spacer element, and the effective focal length f4 of the fourth lens satisfy: -1.5 < R8 / R7 < -1 and 4 < (d4s + D4m) / f4 < 5.2.

[0008] In one embodiment, the spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; the Abbe number V4 of the fourth lens, the Abbe number V3 of the third lens, the combined focal length f34 of the third lens and the fourth lens, and the distance EP34 between the third spacer element and the fourth spacer element on the optical axis satisfy: -24 < (V4 - V3) / f34 × EP34 < -20.5.

[0009] In one embodiment, the spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; the outer diameter D3m of the image side surface of the third spacer element, the inner diameter d3m of the image side surface of the third spacer element, the outer diameter D4s of the object side surface of the fourth spacer element, and the inner diameter d4s of the object side surface of the fourth spacer element satisfy: 1 < (D3m - d3m) / (D4s - d4s) < 1.5.

[0010] In one embodiment, the spacer element group further includes: a second spacer element, which is located on the image side of the second lens and partially bears against the image side surface of the second lens; a third spacer element, which is located on the image side of the third lens and partially bears against the image side surface of the third lens; the center thickness CT3 of the third lens on the optical axis, the center thickness CTn of any lens from the first lens to the sixth lens on the optical axis, and the distance EP23 between the second spacer element and the third spacer element on the optical axis satisfy: 1≤CT3 / CTn<6 and 1 <EP23 / CT3<1.5。

[0011] In one embodiment, the spacer element group further includes: a second spacer element, located on the image side of the second lens and partially supported by the image side surface of the second lens; a third spacer element, located on the image side of the third lens and partially supported by the image side surface of the third lens; the effective focal length f3 of the third lens, the outer diameter D2m of the image side surface of the second spacer element, and the outer diameter D3s of the object side surface of the third spacer element satisfy: 1 <f3 / (D2m+D3s)<1.8。

[0012] In one embodiment, the spacer element group further includes: a first spacer element, which is located on the image side of the first lens and partially bears against the image side surface of the first lens; the distance EP01 between the object side end surface of the lens barrel and the object side surface of the first spacer element on the optical axis, and the axial distance SAG12 from the intersection of the image side surface of the first lens and the optical axis to the vertex of the effective radius of the image side surface of the first lens satisfy: 1.5 <EP01 / SAG12<3.5。

[0013] In one embodiment, the spacer element group also includes: a second spacer element, located on the image side of the second lens and partially supported by the image side surface of the second lens; a third spacer element, located on the image side of the third lens and partially supported by the image side surface of the third lens; the distance between the second spacer element and the third spacer element on the optical axis is greater than the distance between any adjacent spacer elements on the optical axis.

[0014] In one embodiment, the spacer element group further includes: a second spacer element, which is located on the image side of the second lens and partially bears against the image side surface of the second lens; a third spacer element, which is located on the image side of the third lens and partially bears against the image side surface of the third lens; the combined focal length f23 of the second lens and the third lens and the distance EP23 between the second spacer element and the third spacer element on the optical axis satisfy: -4 <f23 / EP23<-2。

[0015] In one embodiment, the inner diameter d0s of the object-side end face of the lens barrel and the inner diameter d0m of the image-side end face of the lens barrel satisfy: 1.5 < d0s / d0m < 3.

[0016] In one embodiment, the first lens is made of glass, and both its object side and image side are spherical surfaces; the spacer element group further includes: a first spacer element located on the image side of the first lens and partially abutting against the image side of the first lens; the effective focal length f1 of the first lens, the refractive index N1 of the first lens, and the outer diameter D1s of the object side of the first spacer element satisfy: -1.4 < f1×N1 / D1s < -0.5.

[0017] In one embodiment, the spacer element group further includes: a second spacer element located on the image side of the second lens and partially abutting against the image side of the second lens; the radius of curvature R3 of the object side of the second lens, the radius of curvature R4 of the image side of the second lens, the effective focal length f2 of the second lens, the outer diameter D2m of the image side of the second spacer element, and the inner diameter d2s of the object side of the second spacer element satisfy: 1.5 < R3 / R4 < 2.2 and -1.6 < f2 / (D2m - d2s) < -0.7.

[0018] The optical imaging system according to an embodiment of the present application includes a lens barrel and a six-piece lens group and a spacer element group accommodated in the lens barrel. The first lens to the sixth lens are arranged in sequence from the object side to the image side along the optical axis. Among them, the effective focal length values of the first lens, the second lens, and the fifth lens are negative; the effective focal length values of the third lens, the fourth lens, and the sixth lens are positive; a fourth spacer element that partially abuts against the image side of the fourth lens is provided on the image side of the fourth lens, and a fifth spacer element that partially abuts against the image side of the fifth lens is provided on the image side of the fifth lens; and, on the premise that the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis and the air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy the conditional formula 2.5 < EP45 / T56 < 5.5, controlling the outer diameter D4m of the image side of the fourth spacer element, the inner diameter d5s of the object side of the fifth spacer element, and the effective focal length f5 of the fifth lens to satisfy the conditional formula -2 < (D4m - d5s) / f5 < -0.5, controlling the effective focal length of the fifth lens is beneficial to restricting the light path in the fifth lens and reducing the sensitivity of the fifth lens; at the same time, by controlling the outer diameter of the image side of the fourth spacer element, the supporting effect on the fourth lens is satisfied; and by controlling the inner diameter of the object side of the fifth spacer element, the outermost effective light can closely adhere to the inner diameter of the spacer element, avoiding stray light caused by too large or too small inner diameter or affecting the optical main value. Description of the Drawings

[0019] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0020] Figure 1 A schematic diagram showing the structure and related parameters of an optical imaging system according to an exemplary embodiment of the present application is shown;

[0021] Figure 2 A schematic structural diagram of an optical imaging system according to Embodiment 1 of the present application is shown;

[0022] Figure 3 A schematic structural diagram of an optical imaging system according to Embodiment 2 of the present application is shown;

[0023] Figure 4 A schematic structural diagram of an optical imaging system according to Embodiment 3 of the present application is shown;

[0024] Figures 5 to 8 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging system according to Embodiment 1, Embodiment 2 and Embodiment 3 of the present application are shown;

[0025] Fig. 9 A schematic structural diagram of an optical imaging system according to Embodiment 4 of the present application is shown;

[0026] Fig.10 A schematic structural diagram of an optical imaging system according to Embodiment 5 of the present application is shown;

[0027] Fig.11 A schematic structural diagram of an optical imaging system according to Embodiment 6 of the present application is shown;

[0028] Figures 12 to 15 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging system according to Embodiment 4, Embodiment 5 and Embodiment 6 of the present application are shown;

[0029] Fig.16 A schematic structural diagram of an optical imaging system according to Embodiment 7 of the present application is shown;

[0030] Fig.17 A schematic structural diagram of an optical imaging system according to Embodiment 8 of the present application is shown;

[0031] Fig.18 A schematic diagram of the structure of an optical imaging system according to Embodiment 9 of the present application is shown; and

[0032] Figures 19 to 22 The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the optical imaging system according to Embodiment 7, Embodiment 8 and Embodiment 9 of the present application are shown;

[0033] Fig.23 The stray light diagram of the optical imaging system is shown when the conditional formula EP45 / T56=-10 and (D4m-d5s) / f5=-15 is satisfied;

[0034] Fig.24 The stray light diagram of the optical imaging system is shown when the conditional formula EP45 / T56=3.66 and (D4m-d5s) / f5=-1.2 is satisfied;

[0035] Fig.25 shows a stray light diagram of the optical imaging system when the conditional formula EP45 / T56=15 and (D4m-d5s) / f5=8 is satisfied; and

[0036] Fig.26 The stray light diagram of the optical imaging system is shown when the conditions EP45 / T56=3.8 and (D4m-d5s) / f5=-1.6 are satisfied. DETAILED DESCRIPTION

[0037] 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 are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0038] 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.

[0039] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. 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 only examples and are not drawn strictly to scale.

[0040] In this article, the paraxial area refers to the area 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 area; 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 area. The judgment of the surface type in the paraxial area can be judged according to the general method in this field, for example, the positive and negative R value (R refers to the radius of curvature of the paraxial area) is used to judge the concave and convex. In this article, the surface of each lens closest to the subject is called the object side of the lens, and the surface of each lens closest to the imaging surface is called the image side of the lens. For the object side, 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; for the image side, 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.

[0041] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", 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 expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "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.

[0042] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as 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.

[0043] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0044] The features, principles and other aspects of the present application are described in detail below.

[0045] An optical imaging system according to an exemplary embodiment of the present application may include a lens barrel and a lens group and a spacer element group accommodated in the lens barrel. The lens group may be a six-piece lens group, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the optical axis.

[0046] In an exemplary embodiment, the effective focal length values of the first lens, the second lens, and the fifth lens may be less than zero. The effective focal length values of the third lens, the fourth lens, and the sixth lens may be greater than zero.

[0047] In an exemplary embodiment, the spacer element group in the optical imaging system may include: a fourth spacer element located on the image side of the fourth lens and partially abutting against the image side surface of the fourth lens; and a fifth spacer element located on the image side of the fifth lens and partially abutting against the image side surface of the fifth lens.

[0048] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 2.5 < EP45 / T56 < 5.5, where EP45 is the distance between the fourth spacer element and the fifth spacer element on the optical axis, that is, the distance on the optical axis from the image side surface of the fourth spacer element to the object side surface of the fifth spacer element; T56 is the air gap between the fifth lens and the sixth lens on the optical axis, that is, the distance on the optical axis from the image side surface of the fifth lens to the object side surface of the sixth lens.

[0049] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula -2 < (D4m - d5s) / f5 < -0.5, where D4m is the outer diameter of the image side surface of the fourth spacer element, d5s is the inner diameter of the object side surface of the fifth spacer element, and f5 is the effective focal length of the fifth lens.

[0050] The optical imaging system according to an embodiment of the present application includes a lens barrel, a six-piece lens group and a spacer element group accommodated in the lens barrel. The first lens to the sixth lens are arranged in sequence from the object side to the image side along the optical axis. Among them, the effective focal length values of the first lens, the second lens and the fifth lens are negative; the effective focal length values of the third lens, the fourth lens and the sixth lens are positive; a fourth spacer element that abuts against a part of the image side surface of the fourth lens is provided on the image side of the fourth lens, and a fifth spacer element that abuts against a part of the image side surface of the fifth lens is provided on the image side of the fifth lens; and, on the premise that the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis and the air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy the conditional expression 2.5 < EP45 / T56 < 5.5, control the outer diameter D4m of the image side surface of the fourth spacer element, the inner diameter d5s of the object side surface of the fifth spacer element and the effective focal length f5 of the fifth lens to satisfy the conditional expression -2 < (D4m - d5s) / f5 < -0.5. Controlling the effective focal length of the fifth lens is beneficial to restricting the light path in the fifth lens and reducing the sensitivity of the fifth lens; at the same time, by controlling the outer diameter of the image side surface of the fourth spacer element, the supporting effect on the fourth lens is satisfied; and by controlling the inner diameter of the object side surface of the fifth spacer element, the outermost effective light can closely adhere to the inner diameter of the spacer element, avoiding stray light or affecting the optical main value due to too large or too small inner diameter.

[0051] See the appendix Figure 23 to Figure 26 , among which, Fig.23 shows a schematic diagram of the stray light situation of the optical imaging system when the conditional expressions EP45 / T56 = -10 and (D4m - d5s) / f5 = -15 are satisfied; Fig.24 shows a schematic diagram of the stray light situation of the optical imaging system when the conditional expressions EP45 / T56 = 3.66 and (D4m - d5s) / f5 = -1.2 are satisfied;

[0052] Fig.25 shows a schematic diagram of the stray light situation of the optical imaging system when the conditional expressions EP45 / T56 = 15 and (D4m - d5s) / f5 = 8 are satisfied; Fig.26 shows a schematic diagram of the stray light situation of the optical imaging system when the conditional expressions EP45 / T56 = 3.8 and (D4m - d5s) / f5 = -1.6 are satisfied. Comparing Figure 23-26 the several situations shown, it can be seen that when the value of the conditional expression EP45 / T56 of the optical imaging system is in the range greater than 2.5 and less than 5.5, and the value of the conditional expression (D4m - d5s) / f5 is in the range greater than -2 and less than -0.5, as Fig.24 and Fig.26As shown, the stray light performance of the optical imaging system is relatively better, and the stray light of the system is significantly reduced; when the value of EP45 / T56 is in the range less than or equal to 2.5 or greater than or equal to 5.5, and the value of (D4m - d5s) / f5 is in the range less than or equal to -2 or greater than or equal to -0.5, the stray light situation of the optical imaging system is relatively poor at this time, as Fig.23 and Fig.25 shown, the stray light of the system cannot be effectively controlled. Therefore, based on the optical imaging system according to the embodiments of the present application, on the premise that the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis and the air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy the conditional formula 2.5 < EP45 / T56 < 5.5, by controlling the outer diameter D4m of the image side surface of the fourth spacer element, the inner diameter d5s of the object side surface of the fifth spacer element and the effective focal length f5 of the fifth lens to satisfy the conditional formula -2 < (D4m - d5s) / f5 < -0.5, the path of the light rays in the fifth lens can be effectively restricted, the sensitivity of the fifth lens can be reduced; and while satisfying the support effect on the fourth lens, the generation of stray light can be effectively reduced, ensuring the optical principal value.

[0053] In an exemplary embodiment, the first lens may have a negative optical power, its object side surface may be convex, and its image side surface may be concave. The second lens may have a negative optical power, its object side surface may be convex, and its image side surface may be concave. The third lens may have a positive optical power, its object side surface may be convex, and its image side surface may be convex. The fourth lens may have a positive optical power, its object side surface may be convex, and its image side surface may be convex. The fifth lens may have a negative optical power, its object side surface may be concave, and its image side surface may be concave. The sixth lens may have a positive optical power, its object side surface may be convex, and its image side surface may be concave.

[0054] In an exemplary embodiment, the spacer element group in the optical imaging system may further include: a first spacer element located on the image side of the first lens and partially abutting against the image side surface of the first lens.

[0055] In an exemplary embodiment, the spacer element group in the optical imaging system may further include: a second spacer element located on the image side of the second lens and partially abutting against the image side surface of the second lens.

[0056] In an exemplary embodiment, the spacer element group in the optical imaging system may further include: a third spacer element located on the image side of the third lens and partially abutting against the image side surface of the third lens.

[0057] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula -24 < f56 / T56 < -20. On this premise, the conditional formula 0 < CP5 / CT6 < 0.9 can be satisfied at the same time, where f56 is the combined focal length of the fifth lens and the sixth lens, T56 is the air gap between the fifth lens and the sixth lens on the optical axis, CP5 is the maximum thickness of the fifth spacer element in the direction along or parallel to the optical axis, and CT6 is the central thickness of the sixth lens on the optical axis. By controlling the ratios of the combined focal length of the fifth lens and the sixth lens to the air gap between the fifth lens and the sixth lens on the optical axis, and the ratio of the maximum thickness of the fifth spacer element to the central thickness of the sixth lens on the optical axis to satisfy the above conditions respectively, the maximum thickness of the fifth spacer element and the edge thickness of the sixth lens can be reasonably distributed, ensuring that the fifth spacer element has a certain thickness and the sixth lens has a reasonable thickness ratio, which is helpful for the forming and processing of the fifth spacer element and the sixth lens.

[0058] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula 1.8 < D5m / R11 < 3.3. On this premise, the conditional formula 0.5 < D5s / R10 < 1.8 can be satisfied at the same time, where D5m is the outer diameter of the image side of the fifth spacer element, R11 is the curvature radius of the object side of the sixth lens, D5s is the outer diameter of the object side of the fifth spacer element, and R10 is the curvature radius of the image side of the fifth lens. By controlling the ratios of the outer diameter of the image side of the fifth spacer element to the curvature radius of the object side of the sixth lens and the outer diameter of the object side of the fifth spacer element to the curvature radius of the image side of the fifth lens to satisfy the above conditions respectively, on the one hand, the overall shape of the fifth lens can be ensured, which is beneficial to the processing of the lens; on the other hand, by controlling the outer diameters of the object side and the image side of the fifth spacer element, it can be ensured that the step difference between the two side bearing surfaces is not large. On the premise of stable assembly, the processability of the fifth spacer element is satisfied.

[0059] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional expression 3.3 < T34 / (CP3 + CP4) < 7, where T34 is the air gap between the third lens and the fourth lens on the optical axis, that is, the distance on the optical axis from the image side of the third lens to the object side of the fourth lens; CP3 is the maximum thickness of the third spacer element, that is, the maximum thickness of the third spacer element in the direction along or parallel to the optical axis; CP4 is the maximum thickness of the fourth spacer element, that is, the maximum thickness of the fourth spacer element in the direction along or parallel to the optical axis. By controlling that the air gap between the third lens and the fourth lens on the optical axis, the maximum thickness of the third spacer element, and the maximum thickness of the fourth spacer element satisfy the conditional expression 3.3 < T34 / (CP3 + CP4) < 7, reasonably controlling the air gap between the third lens and the fourth lens on the optical axis can constrain the surface shapes of the image side of the third lens and the object side of the fourth lens, and reduce the sensitivity of the third and fourth lenses; reasonably controlling the maximum thicknesses of the third and fourth spacer elements can, on the one hand, ensure the processability of the third and fourth spacer elements, and on the other hand, indirectly constrain the edge thickness of the fourth lens, so that it has a thickness ratio conducive to forming.

[0060] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional expressions -1.5 < R8 / R7 < -1 and 4 < (d4s + D4m) / f4 < 5.2, where R8 is the radius of curvature of the image side of the fourth lens, R7 is the radius of curvature of the object side of the fourth lens, d4s is the inner diameter of the object side of the fourth spacer element, D4m is the outer diameter of the image side of the fourth spacer element, and f4 is the effective focal length of the fourth lens. By controlling that the ratio of the radius of curvature of the image side of the fourth lens to the radius of curvature of the object side of the fourth lens, and the ratio of the sum of the inner diameter of the object side of the fourth spacer element and the outer diameter of the image side of the fourth spacer element to the effective focal length of the fourth lens respectively satisfy the above conditions, reasonably controlling the effective focal length of the fourth lens and the radii of curvature of the object side and the image side of the fourth lens helps to constrain the overall structure of the fourth lens. By controlling the outer diameter of the image side of the fourth spacer element and the inner diameter of the object side of the fourth spacer element, on the premise of satisfying the support of the spacer element for the lens, it is possible to avoid the inner diameter of the spacer element being too small to block the effective light and affect the optical main value, and it is also possible to avoid the inner diameter being too large so that the light passes through the lens mechanism part and generates stray light, affecting the imaging.

[0061] In an exemplary embodiment, the optical imaging system of the present application may satisfy the condition -24<(V4-V3) / f34×EP34<-20.5, wherein V4 is the Abbe number of the fourth lens, V3 is the Abbe number of the third lens, f34 is the combined focal length of the third lens and the fourth lens, and EP34 is the distance between the third spacer element and the fourth spacer element on the optical axis, that is, the distance from the image side surface of the third spacer element to the object side surface of the fourth spacer element on the optical axis. By controlling the Abbe number of the fourth lens, the Abbe number of the third lens, the combined focal length of the third lens and the fourth lens, and the distance between the third spacing element and the fourth spacing element on the optical axis to satisfy the conditional formula -24<(V4-V3) / f34×EP34<-20.5, the Abbe numbers and combined focal lengths of the third and fourth lenses can be reasonably controlled, which is beneficial to controlling the refractive index of the third and fourth lenses and the direction of light in the third and fourth lenses, thereby improving the imaging quality; by controlling the distance from the third spacing element to the fourth spacing element on the optical axis, the edge thickness of the fourth lens can be controlled, the overall thickness ratio can be constrained, and the fourth lens has good processability.

[0062] In an exemplary embodiment, the optical imaging system of the present application may satisfy the conditional formula 1<(D3m-d3m) / (D4s-d4s)<1.5, wherein D3m is the outer diameter of the image side surface of the third spacer element, d3m is the inner diameter of the image side surface of the third spacer element, D4s is the outer diameter of the object side surface of the fourth spacer element, and d4s is the inner diameter of the object side surface of the fourth spacer element. By controlling the ratio of the difference between the outer diameter of the image side surface of the third spacer element and the inner diameter of the image side surface of the third spacer element to the difference between the outer diameter of the object side surface of the fourth spacer element and the inner diameter of the object side surface of the fourth spacer element within this range, it is possible to ensure that the light is emitted along the edge of the spacer element by constraining the inner diameters of the image side surface of the third spacer element and the object side surface of the fourth spacer element, while satisfying the support of the third and fourth spacer elements for the lens, thereby avoiding stray light caused by an excessively large inner diameter and affecting the optical principal value due to an excessively small inner diameter.

[0063] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional expressions 1 ≤ CT3 / CTn < 6 and 1 < EP23 / CT3 < 1.5, where CT3 is the central thickness of the third lens on the optical axis; CTn is the central thickness of any one of the first lens to the sixth lens on the optical axis, and n can be equal to 1, 2, 3, 4, 5, or 6; EP23 is the distance between the second spacer and the third spacer on the optical axis, that is, the distance on the optical axis from the image side surface of the second spacer to the object side surface of the third spacer. By controlling the ratio of the central thickness of the third lens on the optical axis to the central thickness of any one of the first lens to the sixth lens on the optical axis, and the ratio of the distance between the second spacer and the third spacer on the optical axis to the central thickness of the third lens on the optical axis to satisfy the above conditions respectively, the central thickness of the third lens is controlled to be the largest in the optical system, and at the same time, the ratio of the distance between the second spacer and the third spacer on the optical axis to the central thickness of the third lens is controlled to constrain the thickness-to-thinness ratio of the third lens, which is beneficial to the processing and forming of the third lens.

[0064] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional expression 1 < f3 / (D2m + D3s) < 1.8, where f3 is the effective focal length of the third lens, D2m is the outer diameter of the image side surface of the second spacer, and D3s is the outer diameter of the object side surface of the third spacer. By controlling the effective focal length of the third lens, the outer diameter of the image side surface of the second spacer, and the outer diameter of the object side surface of the third spacer to satisfy the conditional expression 1 < f3 / (D2m + D3s) < 1.8, the effective focal length of the third lens is reasonably controlled, which can constrain the overall shape of the third lens and is beneficial to controlling the light path in the third lens; since the light path is relatively steep between the first, second, and third lenses, by controlling the outer diameters of the image side surface of the second spacer and the object side surface of the third spacer, it is equivalent to constraining the outer diameters of the second and third lenses, ensuring that the abutment misalignment between the second lens and the third lens is not large, which is beneficial to improving the assembly stability.

[0065] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional expression 1.5 < EP01 / SAG12 < 3.5, where EP01 is the distance between the object side end surface of the lens barrel and the object side surface of the first spacer on the optical axis, and SAG12 is the axial distance from the intersection of the image side surface of the first lens and the optical axis to the vertex of the effective radius of the image side surface of the first lens. By controlling the ratio of the distance between the object side end surface of the lens barrel and the object side surface of the first spacer on the optical axis to the axial distance from the intersection of the image side surface of the first lens and the optical axis to the vertex of the effective radius of the image side surface of the first lens within this range, on the one hand, it can ensure that the effective light can enter the optical system completely for imaging, and on the other hand, it can control the shape of the first lens, which is beneficial to the processing of the first lens.

[0066] In an exemplary embodiment, the distance between the second spacer element and the third spacer element on the optical axis is greater than the distance between any other adjacent spacer elements on the optical axis. The third lens is the middle lens during assembly, and at the same time, the third lens has the thickest central thickness among all the lenses. The distance between the second spacer assembly and the third spacer assembly on the optical axis can thus constrain the edge thickness of the third lens. Therefore, by controlling the above conditions, the thickness ratio of the third lens can be ensured, which is beneficial to the shaping of the third lens.

[0067] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula -4 < f23 / EP23 < -2, where f23 is the combined focal length of the second lens and the third lens, and EP23 is the distance between the second spacer element and the third spacer element on the optical axis. By controlling the ratio of the combined focal length of the second lens and the third lens to the distance between the second spacer element and the third spacer element on the optical axis within this range, the combined focal length of the second and third lenses can be reasonably controlled, which is beneficial to controlling the light path in the second and third lenses and reducing the sensitivity of the lenses; by reasonably controlling the distance between the second spacer element and the third spacer element on the optical axis, the edge thickness of the third lens can be constrained, ensuring an appropriate thickness ratio and meeting the processing requirements of the third lens.

[0068] In an exemplary embodiment, the optical imaging system of the present application can satisfy the conditional formula 1.5 < d0s / d0m < 3, where d0s is the inner diameter of the object-side end face of the lens barrel (i.e., the end face or surface of the lens barrel closest to the object side), and d0m is the inner diameter of the image-side end face of the lens barrel (i.e., the end face or surface of the lens barrel closest to the image side). By controlling the ratio of the inner diameter of the object-side end face of the lens barrel to the inner diameter of the image-side end face of the lens barrel within this range, the uniformity of the lens barrel wall thickness can be maintained, meeting the processing and shaping requirements of the lens barrel. More specifically, d0s and d0m can satisfy: 1.8 < d0s / d0m < 2.6.

[0069] In an exemplary embodiment, the first lens can be made of glass material, and both the object side surface and the image side surface of the first lens can be spherical surfaces; and the optical imaging system of the present application can satisfy the conditional formula -1.4 < f1×N1 / D1s < -0.5, where f1 is the effective focal length of the first lens, N1 is the refractive index of the first lens, and D1s is the outer diameter of the object side surface of the first spacer element. Selecting the first lens made of glass material enables it to have a certain anti-scratch ability after being coated with an AF film (waterproof film). By reasonably controlling the effective focal length and refractive index of the first lens, the optical power of the first lens is ensured; by reasonably controlling the outer diameter of the object side surface of the first spacer element, the outer diameter of the first lens is also constrained. Since the first lens is the lens with the largest size in the lens, it also constrains the outer shape size of the lens barrel. On the premise of ensuring processability, the size can be minimized as much as possible.

[0070] In an exemplary embodiment, the optical imaging system of the present application can satisfy the condition 1.5 < R3 / R4 < 2.2. On this premise, the condition -1.6 < f2 / (D2m - d2s) < -0.7 can be satisfied at the same time, where R3 is the curvature radius of the object side surface of the second lens, R4 is the curvature radius of the image side surface of the second lens, f2 is the effective focal length of the second lens, D2m is the outer diameter of the image side surface of the second spacer element, and d2s is the inner diameter of the object side surface of the second spacer element. By controlling the ratio of the curvature radius of the object side surface of the second lens to the curvature radius of the image side surface of the second lens, and the ratio of the effective focal length of the second lens to the difference between the outer diameter of the image side surface of the second spacer element and the inner diameter of the object side surface of the second spacer element to satisfy the above conditions respectively, the trend of light rays in the second lens can be effectively controlled, the sensitivity of the lens can be reduced, and at the same time, by controlling the outer diameter of the image side surface and the inner diameter of the object side surface of the second spacer element, it is possible to block the stray light generated by the excess light entering the mechanism part of the rear lens while ensuring the optical main value, which helps to improve the imaging quality of the lens.

[0071] In an exemplary embodiment, the optical imaging system of the present application may include at least one aperture stop. The aperture stop can constrain the optical path and control the light intensity. The aperture stop can be set at an appropriate position in the optical imaging system. For example, the aperture stop can be set between the third lens and the fourth lens.

[0072] In an exemplary embodiment, optionally, the above optical imaging system may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0073] In an exemplary embodiment, one or more aspherical surfaces may be provided on the mirror surfaces of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens. The aspherical surface has better curvature radius characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. By using the aspherical surface, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0074] The optical imaging system according to an embodiment of the present application includes a lens barrel, a six-piece lens group and a spacer element group accommodated in the lens barrel. The first lens to the sixth lens are arranged in sequence from the object side to the image side along the optical axis. Among them, the effective focal length values of the first lens, the second lens and the fifth lens are negative; the effective focal length values of the third lens, the fourth lens and the sixth lens are positive; a fourth spacer element that abuts against a part of the image side surface of the fourth lens is provided on the image side of the fourth lens, and a fifth spacer element that abuts against a part of the image side surface of the fifth lens is provided on the image side of the fifth lens; and, on the premise that the distance EP45 between the fourth spacer element and the fifth spacer element on the optical axis and the air gap T56 between the fifth lens and the sixth lens on the optical axis satisfy the conditional formula 2.5 < EP45 / T56 < 5.5, control the outer diameter D4m of the image side surface of the fourth spacer element, the inner diameter d5s of the object side surface of the fifth spacer element and the effective focal length f5 of the fifth lens to satisfy the conditional formula -2 < (D4m - d5s) / f5 < -0.5. Controlling the effective focal length of the fifth lens is beneficial to restricting the traveling direction of light rays in the fifth lens and reducing the sensitivity of the fifth lens; at the same time, by controlling the outer diameter of the image side surface of the fourth spacer element, the supporting effect on the fourth lens is satisfied; and by controlling the inner diameter of the object side surface of the fifth spacer element, the outermost effective light rays can closely adhere to the inner diameter of the spacer element, avoiding stray light generated due to too large or too small inner diameter or affecting the optical main value.

[0075] On the other hand, the optical imaging system according to an embodiment of the present application includes a lens barrel, a six-piece lens group and a spacer element group accommodated in the lens barrel. The first lens to the sixth lens are arranged in sequence from the object side to the image side along the optical axis. Among them, the effective focal length values of the first lens, the second lens and the fifth lens are negative; the effective focal length values of the third lens, the fourth lens and the sixth lens are positive; a fourth spacer element that abuts against a part of the image side surface of the fourth lens is provided on the image side of the fourth lens, and a fifth spacer element that abuts against a part of the image side surface of the fifth lens is provided on the image side of the fifth lens; and, control the radius of curvature R8 of the image side surface of the fourth lens and the radius of curvature R7 of the object side surface of the fourth lens to satisfy the conditional formula -1.5 < R8 / R7 < -1. At the same time, control the inner diameter d4s of the object side surface of the fourth spacer element, the outer diameter D4m of the image side surface of the fourth spacer element and the effective focal length f4 of the fourth lens to satisfy the conditional formula 4 < (d4s + D4m) / f4 < 5.2. Reasonably controlling the effective focal length of the fourth lens and the radii of curvature of the object side surface and the image side surface of the fourth lens helps to restrict the overall structure of the fourth lens. By controlling the outer diameter of the image side surface of the fourth spacer element and the inner diameter of the object side surface of the fourth spacer element, on the premise of satisfying the support of the spacer element for the lens, it is possible to avoid the inner diameter of the spacer element being too small to block the effective light rays and affect the optical main value, and it is also possible to avoid the inner diameter being too large to cause stray light when the light rays pass through the lens mechanism part and affect the imaging.

[0076] In another aspect, an optical imaging system according to an embodiment of the present application includes a lens barrel, a six-piece lens group, and a spacer element group accommodated in the lens barrel. The first lens to the sixth lens are arranged in order from the object side to the image side along the optical axis. Among them, the effective focal length values of the first lens, the second lens, and the fifth lens are negative; the effective focal length values of the third lens, the fourth lens, and the sixth lens are positive; a fourth spacer element that abuts against a part of the image side surface of the fourth lens is provided on the image side of the fourth lens, and a fifth spacer element that abuts against a part of the image side surface of the fifth lens is provided on the image side of the fifth lens; and, the first lens is made of glass, and both the object side surface and the image side surface of the first lens are spherical surfaces; at the same time, the effective focal length f1 of the first lens, the refractive index N1 of the first lens, and the outer diameter D1s of the object side surface of the first spacer element are controlled to satisfy the conditional formula -1.4 < f1 × N1 / D1s < -0.5. Selecting glass material for the first lens enables it to have a certain anti-scratch ability after being coated with an AF film (waterproof film). By reasonably controlling the effective focal length and refractive index of the first lens, the optical power of the first lens is ensured; by reasonably controlling the outer diameter of the object side surface of the first spacer element, the outer diameter of the first lens is also restricted. Since the first lens is the lens with the largest size in the lens, it also restricts the outer shape size of the lens barrel. On the premise of ensuring processability, the size can be made as small as possible.

[0077] 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, and the number of spacer elements can also be changed to obtain the various results and advantages described in this specification. The present application does not make specific limitations in this regard. For example, although six lenses are described as an example in the embodiment, the optical imaging system is not limited to including six lenses. If necessary, the optical imaging system may further include other numbers of lenses. Again, for example, according to needs, the optical imaging system may also include other numbers of spacer elements different from those described in the above embodiment.

[0078] The following further describes specific embodiments of the optical imaging system applicable to the above embodiment with reference to the drawings.

[0079] Example 1

[0080] The following refers to Figure 2 Describe the optical imaging system according to Embodiment 1 of the present application.

[0081] As Figure 2 shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 that are accommodated in the lens barrel and arranged in order from the object side to the image side along the optical axis.

[0082] In this embodiment, the optical imaging system further comprises a plurality of spacer elements: a first spacer element P1, located on the image side of the first lens E1 and partially bearing against the image side surface of the first lens E1; a second spacer element P2, located on the image side of the second lens E2 and partially bearing against the image side surface of the second lens E2; a third spacer element P3, located on the image side of the third lens E3 and partially bearing against the image side surface of the third lens E3; a fourth spacer element P4, located on the image side of the fourth lens E4 and partially bearing against the image side surface of the fourth lens E4; and a fifth spacer element P5, located on the image side of the fifth lens E5 and partially bearing against the image side surface of the fifth lens E5.

[0083] In this embodiment, the first lens E1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative power, its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive power, its object side surface S5 is convex, and its image side surface S6 is convex. The fourth lens E4 has positive power, its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has negative power, its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive power, its object side surface S11 is convex, and its image side surface S12 is concave.

[0084] Table 1 shows the basic parameters of the optical imaging system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0085]

[0086] Table 1

[0087] In Example 1, the object side surface and the image side surface of any lens from the second lens E2 to the sixth lens E6 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:

[0088]

[0089] 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 below gives 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, 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0090]

[0091]

[0092] Table 2

[0093] Example 2

[0094] The following reference Figure 3 Describe the optical imaging system according to Example 2 of the present application.

[0095] like Figure 3 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0096] The structure of the optical imaging system of this embodiment is the same as that of the optical imaging system of Embodiment 1, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 1, and the high-order coefficient table of the aspheric mirror surface is the same as Table 2.

[0097] The difference between this embodiment and embodiment 1 lies in the different parameters such as the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 1 are shown in Table 7 below, and the multiple parameters specifically include:

[0098] The outer diameter D1s of the object side surface of the first spacing element P1, the inner diameter d2s of the object side surface of the second spacing element P2, the outer diameter D2m of the image side surface of the second spacing element P2, the inner diameter d3m of the image side surface of the third spacing element P3, the outer diameter D3s of the object side surface of the third spacing element P3, the outer diameter D3m of the image side surface of the third spacing element P3, the inner diameter d4s of the object side surface of the fourth spacing element P4, the outer diameter D4s of the object side surface of the fourth spacing element P4, the outer diameter D4m of the image side surface of the fourth spacing element P4, the inner diameter d5s of the object side surface of the fifth spacing element P5, the outer diameter D5s of the object side surface of the fifth spacing element P5, the outer diameter D5m of the image side surface of the fifth spacing element P5 m, the inner diameter d0s of the object side end face of the lens barrel, the inner diameter d0m of the image side end face of the lens barrel, the distance EP01 from the object side end face of the lens barrel to the object side face of the first spacer element P1 on the optical axis, the distance EP23 from the image side face of the second spacer element P2 to the object side face of the third spacer element P3 on the optical axis, the maximum thickness CP3 of the third spacer element P3, the distance EP34 from the image side face of the third spacer element P3 to the object side face of the fourth spacer element P4 on the optical axis, the maximum thickness CP4 of the fourth spacer element P4, the distance EP45 from the image side face of the fourth spacer element P4 to the object side face of the fifth spacer element P5 on the optical axis, and the maximum thickness CP5 of the fifth spacer element P5. The units of the numerical values ​​of the parameters shown in Table 7 are all millimeters (mm), and the schematic diagram of the parameters in the structural diagram of the optical imaging system is as follows: Figure 1 shown.

[0099] Example 3

[0100] The following reference Figure 4 Describe the optical lens according to Example 3 of the present application.

[0101] like Figure 4 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0102] The structure of the optical imaging system of this embodiment is also the same as that of the optical imaging system of Embodiment 1, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 1, and the high-order coefficient table of the aspheric mirror surface is the same as Table 2.

[0103] The difference between this embodiment and embodiment 1 lies in the difference in parameters such as the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 1 are also shown in Table 7 below, and the specific description of the multiple parameters is the same as the relevant description in the above embodiment 2, which will not be repeated here.

[0104] Figure 5 The axial chromatic aberration curves of the optical imaging systems of Embodiment 1, Embodiment 2 and Embodiment 3 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Figure 6 Astigmatism curves of the optical imaging systems of Example 1, Example 2 and Example 3 are shown, which represent meridional image curvature and sagittal image curvature. Figure 7 Distortion curves of the optical imaging systems of Embodiment 1, Embodiment 2 and Embodiment 3 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 8 The magnification chromatic aberration curves of the optical imaging systems of Example 1, Example 2 and Example 3 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the lens. Figures 5 to 8 It can be seen that the optical imaging systems provided in Embodiment 1, Embodiment 2 and Embodiment 3 can achieve good imaging quality.

[0105] Example 4

[0106] The following reference Fig. 9 Describe the optical imaging system according to Example 4 of the present application.

[0107] like Fig. 9 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis.

[0108] In this embodiment, the optical imaging system further comprises a plurality of spacer elements: a first spacer element P1, located on the image side of the first lens E1 and partially bearing against the image side surface of the first lens E1; a second spacer element P2, located on the image side of the second lens E2 and partially bearing against the image side surface of the second lens E2; a third spacer element P3, located on the image side of the third lens E3 and partially bearing against the image side surface of the third lens E3; a fourth spacer element P4, located on the image side of the fourth lens E4 and partially bearing against the image side surface of the fourth lens E4; and a fifth spacer element P5, located on the image side of the fifth lens E5 and partially bearing against the image side surface of the fifth lens E5.

[0109] In this embodiment, the first lens E1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative power, its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive power, its object side surface S5 is convex, and its image side surface S6 is convex. The fourth lens E4 has positive power, its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has negative power, its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive power, its object side surface S11 is convex, and its image side surface S12 is concave.

[0110] Table 3 shows the basic parameters of the optical imaging system of Example 4, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0111]

[0112]

[0113] Table 3

[0114] In this embodiment, the object side surface and the image side surface of any lens of the second lens E2 to the sixth lens E6 are both aspherical surfaces, and the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. Table 4 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, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0115] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S3 -4.2075E-01 -5.8313E-01 -6.8635E-02 -5.6270E-03 -7.5493E-03 -1.7359E-03 -1.2662E-03 -4.8670E-04 -2.1828E-04 S4 -9.7964E-01 -9.2334E-02 -3.9246E-02 -4.1970E-03 -4.0683E-03 -4.6725E-04 1.3684E-05 2.9214E-04 1.7141E-04 S5 5.4323E-03 -9.7031E-02 -5.4979E-03 -8.4007E-04 -4.6740E-05 3.9725E-05 1.2024E-04 2.9776E-05 2.2509E-05 S6 -2.3746E+00 -4.0602E-02 4.4424E-03 -4.0317E-04 7.3150E-05 -1.6645E-05 -1.3235E-06 4.0956E-06 -2.9288E-06 S7 -3.4044E-01 -6.4593E-02 5.1401E-03 -4.0256E-04 1.9867E-04 -1.7791E-06 -7.0648E-06 -2.4042E-06 4.3951E-06 S8 -9.7937E-01 -3.0078E-03 8.3844E-04 2.4568E-03 -9.1366E-04 4.1766E-04 -1.1204E-04 7.8862E-05 -9.8108E-06 S9 2.9172E+00 -6.2529E-03 6.4812E-03 3.7180E-03 -6.8965E-04 9.1480E-04 -2.4123E-05 1.1270E-04 -4.8666E-05 S10 -3.3460E-01 -5.6686E-02 1.0293E-02 -9.2716E-04 1.0163E-04 3.4758E-04 1.7694E-05 7.2295E-05 3.8444E-06 S11 4.4381E-01 -3.4209E-01 -1.1291E-02 -8.9133E-03 -1.2993E-03 -6.0847E-04 -2.8536E-04 -1.1106E-04 -6.7470E-05 S12 4.2676E+00 -2.0530E-01 -1.7900E-02 2.3320E-04 -7.0887E-04 1.9295E-04 -1.0837E-04 -1.4117E-05 -3.8056E-05

[0116] Table 4

[0117] Example 5

[0118] The following reference Fig.10Describe the optical imaging system according to Example 5 of the present application.

[0119] like Fig.10 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0120] The structure of the optical imaging system of this embodiment is the same as that of the optical imaging system of Embodiment 4, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 3, and the high-order coefficient table of the aspheric mirror is the same as Table 4.

[0121] The difference between this embodiment and embodiment 4 is that the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis are different. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 4 are shown in Table 7 below, and the specific description of the multiple parameters is the same as the relevant description in the above embodiment 2, which will not be repeated here.

[0122] Example 6

[0123] The following reference Fig.11 Describe the optical lens according to Example 6 of the present application.

[0124] like Fig.11As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0125] The structure of the optical imaging system of this embodiment is also the same as that of the optical imaging system of Embodiment 4, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 3, and the high-order coefficient table of the aspheric mirror surface is the same as Table 4.

[0126] The difference between this embodiment and embodiment 4 is that the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis are different. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 4 are also shown in Table 7 below, and the specific description of the multiple parameters is also the same as the relevant description in the above embodiment 2, which will not be repeated here.

[0127] Fig.12 The axial chromatic aberration curves of the optical imaging systems of Examples 4, 5 and 6 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Fig.13 Astigmatism curves of the optical imaging systems of Example 4, Example 5 and Example 6 are shown, which represent meridional image plane curvature and sagittal image plane curvature. Fig.14 The distortion curves of the optical imaging systems of Embodiment 4, Embodiment 5 and Embodiment 6 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.15 The magnification chromatic aberration curves of the optical imaging systems of Example 4, Example 5 and Example 6 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the lens. Figures 12 to 15 It can be seen that the optical imaging systems provided in Embodiment 4, Embodiment 5 and Embodiment 6 can achieve good imaging quality.

[0128] Example 7

[0129] The following reference Fig.16 Describe the optical imaging system according to Example 7 of the present application.

[0130] like Fig.16 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis.

[0131] In this embodiment, the optical imaging system further comprises a plurality of spacer elements: a first spacer element P1, located on the image side of the first lens E1 and partially bearing against the image side surface of the first lens E1; a second spacer element P2, located on the image side of the second lens E2 and partially bearing against the image side surface of the second lens E2; a third spacer element P3, located on the image side of the third lens E3 and partially bearing against the image side surface of the third lens E3; a fourth spacer element P4, located on the image side of the fourth lens E4 and partially bearing against the image side surface of the fourth lens E4; and a fifth spacer element P5, located on the image side of the fifth lens E5 and partially bearing against the image side surface of the fifth lens E5.

[0132] In this embodiment, the first lens E1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has negative power, its object side surface S3 is convex, and its image side surface S4 is concave. The third lens E3 has positive power, its object side surface S5 is convex, and its image side surface S6 is convex. The fourth lens E4 has positive power, its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has negative power, its object side surface S9 is concave, and its image side surface S10 is concave. The sixth lens E6 has positive power, its object side surface S11 is convex, and its image side surface S12 is concave.

[0133] Table 5 shows the basic parameters of the optical imaging system of Example 7, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0134]

[0135]

[0136] Table 5

[0137] In this embodiment, the object side surface and the image side surface of any lens of the second lens E2 to the sixth lens E6 are both aspherical surfaces, and the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. Table 6 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, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0138] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S3 -5.6814E-01 -6.7702E-02 -1.2734E-02 -9.3356E-03 -1.1179E-03 -1.1929E-03 -1.0824E-03 -5.9110E-04 -1.3464E-04 S4 -9.5373E-02 -4.1747E-02 -5.7300E-03 -2.7329E-03 1.1385E-03 6.2076E-04 -1.6492E-04 -3.7836E-04 -1.4981E-04 S5 -1.0482E-01 -4.6224E-03 -7.2630E-05 1.3217E-04 8.0014E-05 -2.6173E-05 -3.3049E-06 2.6136E-05 8.8348E-06 S6 -4.0728E-02 5.0753E-03 -4.2864E-04 -5.6062E-06 -1.2351E-04 -7.6761E-05 -4.1173E-05 -2.0285E-05 -2.2489E-06 S7 -6.2294E-02 6.0211E-03 -4.7144E-04 2.0371E-04 -2.9296E-05 2.6143E-05 2.0274E-05 1.7563E-05 3.0986E-06 S8 -2.3010E-03 1.1262E-04 2.8780E-03 -8.4495E-04 6.0618E-04 -2.1021E-04 8.0668E-05 -2.6874E-05 9.7552E-06 S9 -7.2931E-03 4.9263E-03 3.5652E-03 -4.3352E-04 7.8170E-04 -3.7852E-04 4.1232E-05 -6.1439E-05 1.6265E-05 S10 -5.4140E-02 1.2234E-02 -2.5275E-03 8.4741E-05 3.3538E-04 -2.3333E-05 8.3092E-05 9.3134E-06 1.4586E-05 S11 -3.7475E-01 -4.6379E-03 -9.3600E-03 -1.6354E-03 -3.1205E-04 -2.3573E-04 -1.0665E-04 -6.2374E-05 -2.6924E-05 S12 -1.9544E-01 -1.2050E-02 7.7722E-04 -1.6564E-03 1.9155E-04 -5.2965E-05 -2.8949E-05 1.4547E-05 -7.3979E-06

[0139] Table 6

[0140] Example 8

[0141] The following reference Fig.17 Describe the optical imaging system according to Example 8 of the present application.

[0142] like Fig.17 As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0143] The structure of the optical imaging system of this embodiment is the same as that of the optical imaging system of Example 7, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 5, and the high-order coefficient table of the aspheric mirror is the same as Table 6.

[0144] The difference between this embodiment and embodiment 7 is that the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis are different. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 7 are shown in Table 7 below. The specific description of the multiple parameters is the same as the relevant description in the above embodiment 2, and will not be repeated here.

[0145] Example 9

[0146] The following reference Fig.18 Describe the optical lens according to Example 9 of the present application.

[0147] like Fig.18As shown, in this embodiment, the optical imaging system includes a lens barrel and a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 which are accommodated in the lens barrel and arranged in sequence from the object side to the image side along the optical axis. The optical imaging system also includes a plurality of spacing elements: a first spacing element P1, which is located on the image side of the first lens E1 and partially bears against the image side surface of the first lens E1; a second spacing element P2, which is located on the image side of the second lens E2 and partially bears against the image side surface of the second lens E2; a third spacing element P3, which is located on the image side of the third lens E3 and partially bears against the image side surface of the third lens E3; a fourth spacing element P4, which is located on the image side of the fourth lens E4 and partially bears against the image side surface of the fourth lens E4; and a fifth spacing element P5, which is located on the image side of the fifth lens E5 and partially bears against the image side surface of the fifth lens E5.

[0148] The structure of the optical imaging system of this embodiment is also the same as the structure of the optical imaging system of Example 7, that is, the basic parameter table of the optical imaging system of this embodiment is the same as Table 5, and the high-order coefficient table of the aspheric mirror surface is the same as Table 6.

[0149] The difference between this embodiment and embodiment 7 is that the structural dimensions of the lens barrel and some of the spacing elements and the spacing of some of the spacing elements along the optical axis are different. The values ​​of multiple parameters of the lens barrel and the spacing elements included in the optical imaging system of this embodiment and embodiment 7 are also shown in Table 7 below, and the specific description of the multiple parameters is also the same as the relevant description in the above embodiment 2, which will not be repeated here.

[0150] Fig.19 The axial chromatic aberration curves of the optical imaging systems of Example 7, Example 8 and Example 9 are shown, which indicate the deviation of the convergent focus of light rays of different wavelengths after passing through the lens. Fig. 20 Astigmatism curves of the optical imaging systems of Example 7, Example 8 and Example 9 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Fig.21 Distortion curves of the optical imaging systems of Embodiment 7, Embodiment 8 and Embodiment 9 are shown, which represent the distortion magnitude values ​​corresponding to different image heights. Fig. 22 The magnification chromatic aberration curves of the optical imaging systems of Example 7, Example 8 and Example 9 are shown, which represent the deviations of different image heights on the imaging surface after the light passes through the lens. Figures 19 to 22 It can be seen that the optical imaging systems provided in Examples 7, 8 and 9 can achieve good imaging quality.

[0151]

[0152]

[0153] Table 7

[0154] In addition, in Examples 1 to 9, the effective focal length values ​​f1 to f6 of the first lens to the sixth lens, the combined focal length f23 of the second lens and the third lens, the combined focal length f34 of the third lens and the fourth lens, and the on-axis distance SAG12 from the intersection of the image side surface of the first lens and the optical axis to the vertex of the effective radius of the image side surface of the first lens are respectively as shown in Table 8 below.

[0155] Parameters / Examples 1 2 3 4 5 6 7 8 9 f1(mm) -3.5827 -3.5827 -3.5827 -3.2344 -3.2344 -3.2344 -3.7342 -3.7342 -3.7342 f2(mm) -3.6253 -3.6253 -3.6253 -3.4425 -3.4425 -3.4425 -3.4758 -3.4758 -3.4758 f3(mm) 12.9589 12.9589 12.9589 13.0553 13.0553 13.0553 13.4592 13.4592 13.4592 f4(mm) 1.1476 1.1476 1.1476 1.1719 1.1719 1.1719 1.1402 1.1402 1.1402 f5(mm) -1.5928 -1.5928 -1.5928 -1.5424 -1.5424 -1.5424 -1.6379 -1.6379 -1.6379 f6(mm) 3.8088 3.8088 3.8088 3.4787 3.4787 3.4787 3.9092 3.9092 3.9092 f23(mm) -5.3824 -5.3824 -5.3824 -4.9984 -4.9984 -4.9984 -5.0839 -5.0839 -5.0839 f34(mm) 1.1455 1.1455 1.1455 1.1930 1.1930 1.1930 1.1289 1.1289 1.1289 SAG12(mm) 0.6669 0.6669 0.6669 0.8251 0.8251 0.8251 0.8881 0.8881 0.8881

[0156] Table 8 Examples 1 to 9 respectively satisfy the conditions shown in Table 9 below.

[0157] Conditional / Example 1 2 3 4 5 6 7 8 9 EP45 / T56 3.5308 4.3209 4.3456 3.5988 3.6572 3.7332 3.8063 3.8063 3.7861 (D4m-d5s) / f5 -1.0874 -1.2933 -1.3875 -1.2020 -1.2669 -1.2338 -1.4891 -1.5569 -1.5660 f56 / T56 -20.6442 -20.6442 -20.6442 -23.4853 -23.4853 -23.4853 -21.3436 -21.3436 -21.3436 CP5 / CT6 0.4812 0.0436 0.0238 0.4070 0.3950 0.3842 0.0274 0.0373 0.0523 D5m / R11 2.1310 2.5557 2.6309 2.6982 2.7775 2.7918 2.8647 2.9382 2.9676 D5s / R10 1.1037 1.2572 1.2941 1.4514 1.4991 1.4991 1.3769 1.4122 1.4263 T34 / (CP3+CP4) 6.0910 5.4819 3.9868 6.4504 4.5532 6.8299 5.6963 3.7285 3.8692 R8 / R7 -1.2210 -1.2210 -1.2210 -1.2132 -1.2132 -1.2132 -1.2321 -1.2321 -1.2321 (d4s+D4m) / f4 4.3613 4.4746 4.5181 4.8613 4.9296 4.9151 4.6939 4.7904 4.8290 (V4-V3) / f34×EP34 -21.7675 -21.7053 -21.3944 -23.3505 -23.2012 -23.4401 -21.6461 -21.3621 -21.2990 (D3m-d3m) / (D4s-d4s) 1.2347 1.2280 1.2149 1.2919 1.2795 1.2613 1.1928 1.1869 1.1846 EP23 / CT3 1.3008 1.2867 1.2792 1.1859 1.1797 1.1785 1.2729 1.2617 1.2537 CT3 / CT1 1.0000 1.0000 1.0000 2.0018 2.0018 2.0018 1.1118 1.1118 1.1118 CT3 / CT2 3.9947 3.9947 3.9947 5.0469 5.0469 5.0469 4.4124 4.4124 4.4124 CT3 / CT4 1.4275 1.4275 1.4275 1.6475 1.6475 1.6475 1.5564 1.5564 1.5564 CT3 / CT5 2.6202 2.6202 2.6202 5.5611 5.5611 5.5611 3.0608 3.0608 3.0608 CT3 / CT6 1.5865 1.5865 1.5865 1.9295 1.9295 1.9295 1.5567 1.5567 1.5567 f3 / (D2m+D3s) 1.4561 1.4241 1.3934 1.3187 1.2926 1.2926 1.3875 1.3595 1.3486 EP01 / SAG12 2.9315 2.9585 2.9285 2.0906 2.1439 2.1148 2.3757 2.4084 2.4366 f23 / EP23 -3.4480 -3.4860 -3.5064 -2.6225 -2.6363 -2.6391 -3.1934 -3.2217 -3.2423 d0s / d0m 2.0872 2.1216 2.1131 2.4609 2.4415 2.3760 2.1927 2.1866 2.1739 f1×N1 / D1s -1.0972 -1.0786 -1.0606 -0.9119 -0.8977 -0.8977 -1.0698 -1.0528 -1.0462 f2 / (D2m-d2s) -1.2024 -1.1751 -1.1206 -1.0295 -0.9938 -0.9978 -1.0400 -1.0128 -1.0022 R3 / R4 1.7273 1.7273 1.7273 1.7695 1.7695 1.7695 1.7433 1.7433 1.7433

[0158] Table 9

[0159] The present application also provides an imaging device, which is provided with an electronic photosensitive element for imaging, and the electronic photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (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 system described above.

[0160] 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 protection 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 concept of the present application. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) to form a technical solution.

Claims

1. An optical imaging system, characterized in that, it includes a lens barrel and a lens group and a spacer element group accommodated in the lens barrel, wherein, the lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side along the optical axis; wherein, the effective focal length values of the first lens, the second lens and the fifth lens are less than zero; the effective focal length values of the third lens, the fourth lens and the sixth lens are greater than zero; the spacer element group includes: a fourth spacer element, located on the image side of the fourth lens and partially abutted against the image side surface of the fourth lens; a fifth spacer element, located on the image side of the fifth lens and partially abutted against the image side surface of the fifth lens; and the optical imaging system satisfies: 2.5 < EP45 / T56 < 5.5 and -2 < (D4m - d5s) / f5 < -0.5, wherein, EP45 is the distance between the fourth spacer element and the fifth spacer element on the optical axis, T56 is the air gap between the fifth lens and the sixth lens on the optical axis, D4m is the outer diameter of the image side surface of the fourth spacer element, d5s is the inner diameter of the object side surface of the fifth spacer element, and f5 is the effective focal length of the fifth lens.

2. The optical imaging system according to claim 1, characterized in that, the combined focal length f56 of the fifth lens and the sixth lens, the maximum thickness CP5 of the fifth spacer element, and the central thickness CT6 of the sixth lens on the optical axis satisfy: -24 < f56 / T56 < -20 and 0 < CP5 / CT6 < 0.

9.

3. The optical imaging system according to claim 1, characterized in that, the outer diameter D5m of the image side surface of the fifth spacer element, the curvature radius R11 of the object side surface of the sixth lens, the outer diameter D5s of the object side surface of the fifth spacer element, and the curvature radius R10 of the image side surface of the fifth lens satisfy: 1.8 < D5m / R11 < 3.3 and 0.5 < D5s / R10 < 1.

8.

4. The optical imaging system according to claim 1, characterized in that, the spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutted against the image side surface of the third lens; the air gap T34 between the third lens and the fourth lens on the optical axis, the maximum thickness CP3 of the third spacer element, and the maximum thickness CP4 of the fourth spacer element satisfy: 3.3 < T34 / (CP3 + CP4) < 7.

5. The optical imaging system according to claim 1, characterized in that, the curvature radius R8 of the image side surface of the fourth lens, the curvature radius R7 of the object side surface of the fourth lens, the inner diameter d4s of the object side surface of the fourth spacer element, the outer diameter D4m of the image side surface of the fourth spacer element and the effective focal length f4 of the fourth lens satisfy: -1.5 < R8 / R7 < -1 and 4 < (d4s + D4m) / f4 < 5.

2.

6. The optical imaging system according to claim 1, characterized in that, The spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; The Abbe number V4 of the fourth lens, the Abbe number V3 of the third lens, the combined focal length f34 of the third lens and the fourth lens, and the distance EP34 between the third spacing element and the fourth spacing element on the optical axis satisfy: -24<(V4-V3) / f34×EP34<-20.

5.

7. The optical imaging system according to claim 1, It is characterized in that The spacer element group further includes: a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; The outer diameter D3m of the image-side surface of the third spacing element, the inner diameter d3m of the image-side surface of the third spacing element, the outer diameter D4s of the object-side surface of the fourth spacing element, and the inner diameter d4s of the object-side surface of the fourth spacing element satisfy: 1<(D3m-d3m) / (D4s-d4s)<1.

5.

8. The optical imaging system according to any one of claims 1 to 7, It is characterized in that The spacer element group further includes: a second spacer element, located on the image side of the second lens and partially abutting against the image side surface of the second lens; a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; The center thickness CT3 of the third lens on the optical axis, the center thickness CTn of any lens from the first lens to the sixth lens on the optical axis, and the distance EP23 between the second spacer element and the third spacer element on the optical axis satisfy: 1≤CT3 / CTn<6 and 1 <EP23 / CT3<1.5。 9. The optical imaging system according to any one of claims 1 to 7, It is characterized in that The spacer element group further includes: a second spacer element, located on the image side of the second lens and partially abutting against the image side surface of the second lens; a third spacer element, located on the image side of the third lens and partially abutting against the image side surface of the third lens; The effective focal length f3 of the third lens, the outer diameter D2m of the image side surface of the second spacing element, and the outer diameter D3s of the object side surface of the third spacing element satisfy: 1 <f3 / (D2m+D3s)<1.8。 10. The optical imaging system according to any one of claims 1 to 7, It is characterized in that The spacer element group further includes: a first spacer element, located on the image side of the first lens and partially abutting against the image side surface of the first lens; The distance EP01 between the object side end surface of the lens barrel and the object side surface of the first spacer element on the optical axis, and the on-axis distance SAG12 from the intersection of the image side surface of the first lens and the optical axis to the vertex of the effective radius of the image side surface of the first lens satisfy: 1.5 <EP01 / SAG12<3.5。 11. The optical imaging system according to any one of claims 1 to 7, It is characterized in that The spacer element group further includes: a second spacer element, located on the image side of the second lens and abutting against a part of the image side surface of the second lens; a third spacer element, located on the image side of the third lens and abutting against a part of the image side surface of the third lens. The distance between the second spacer element and the third spacer element on the optical axis is greater than the distance between any adjacent spacer elements on the optical axis.

12. The optical imaging system according to any one of claims 1 to 7, wherein, The spacer element group further includes: a second spacer element, located on the image side of the second lens and abutting against a part of the image side surface of the second lens; a third spacer element, located on the image side of the third lens and abutting against a part of the image side surface of the third lens. The combined focal length f23 of the second lens and the third lens and the distance EP23 between the second spacer element and the third spacer element on the optical axis satisfy: -4 < f23 / EP23 < -2.

13. The optical imaging system according to any one of claims 1 to 7, wherein, The inner diameter d0s of the object-side end face of the lens barrel and the inner diameter d0m of the image-side end face of the lens barrel satisfy: 1.5 < d0s / d0m < 3.

14. The optical imaging system according to any one of claims 1 to 7, wherein, The first lens is made of glass, and both its object side surface and image side surface are spherical surfaces; the spacer element group further includes: a first spacer element, located on the image side of the first lens and abutting against a part of the image side surface of the first lens. The effective focal length f1 of the first lens, the refractive index N1 of the first lens, and the outer diameter D1s of the object side surface of the first spacer element satisfy: -1.4 < f1×N1 / D1s < -0.

5.

15. The optical imaging system according to any one of claims 1 to 7, wherein, The spacer element group further includes: a second spacer element, located on the image side of the second lens and abutting against a part of the image side surface of the second lens. The radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens, the effective focal length f2 of the second lens, the outer diameter D2m of the image side surface of the second spacer element, and the inner diameter d2s of the object side surface of the second spacer element satisfy: 1.5 < R3 / R4 < 2.2 and -1.6 < f2 / (D2m - d2s) < -0.7.

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