Optical image capturing system

Abstract

The invention provides an optical imaging system. The optical imaging system comprises a lens barrel, a lens group and a spacing element group, and the lens group and the spacing element group are arranged in the lens barrel. The six lenses are sequentially a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power, a fourth lens with focal power, a fifth lens with focal power and a sixth lens with focal power from the object side to the image side; the spacing element group comprises a first spacing element, a second spacing element and a third spacing element; the following conditions are satisfied: 1lt; tr1r4 / Tr5r12lt, Tr1r4 / 1.2; the formula is as follows:-1.25 < = d2s / f12lt; and-0.5. According to the invention, the problem of discretization caused by increasing the thickness of the front-end lens in a six-piece optical imaging system in the prior art to satisfy a large field of view is solved.

Description

Technical Field

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

[0002] In the field of modern optical imaging technology, with the continuous improvement of the requirements for imaging quality, the design and manufacture of optical imaging systems face many challenges, especially for six-piece optical imaging systems. However, in order to meet the requirements of a large field of view and a large shooting range, the existing six-piece optical imaging systems often achieve this by increasing the thickness of the front lens. However, this design often leads to a more sensitive surface shape of the front lens and a thicker edge thickness, which easily causes the occurrence of discrete problems.

[0003] That is to say, the existing six-piece optical imaging systems have the problem of increasing the thickness of the front lens to meet the large field of view, resulting in discrete problems. Summary of the Invention

[0004] The main object of the present invention is to provide an optical imaging system to solve the problem that the existing six-piece optical imaging system increases the thickness of the front lens to meet the large field of view, resulting in discrete problems.

[0005] To achieve the above object, according to one aspect of the present invention, there is provided an optical imaging system, including a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with an optical power, and a sixth lens with an optical power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between two adjacent lenses among the first lens to the sixth lens; the spacer element group includes a first spacer element disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the axial distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens and the axial distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens satisfy: 1 < Tr1r4 / Tr5r12 < 1.2; the object side inner diameter d2s of the second spacer element and the combined focal length f12 of the first lens and the second lens satisfy: -1.25 ≤ d2s / f12 < -0.5.

[0006] According to another aspect of the present invention, an optical imaging system is provided, which includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with an optical power, and a sixth lens with an optical power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between two adjacent lenses among the first lens to the sixth lens; the spacer element group includes a first spacer element disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the on-axis distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens and the on-axis distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens satisfy: 1 < Tr1r4 / Tr5r12 < 1.2; the inner diameter d0s of the object side end face of the lens barrel, the inner diameter d1s of the object side of the first spacer element, and the effective focal length f1 of the first lens satisfy: -2.8 < (d0s - d1s) / f1 < -1.8.

[0007] According to another aspect of the present invention, an optical imaging system is provided, which includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with an optical power, and a sixth lens with an optical power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between adjacent two of the first lens to the sixth lens; the spacer element group includes a first spacer element disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element, and the center thickness CP2 of the second spacer element, the center thickness CP2b of the second auxiliary spacer element, and the sum ∑AT of the air gaps on the optical axis between adjacent two of the first lens to the sixth lens satisfy: 0.3 < (CP2 + CP2b) / ∑AT < 0.6; the outer diameter D1m on the image side of the first spacer element, the inner diameter d1m on the image side of the first spacer element, and the curvature radius R3 of the object side surface of the second lens satisfy: -3.7 < R3 / (D1m - d1m) < 16.4.

[0008] Further, the spacer element group further includes a second auxiliary spacer element disposed between the second spacer element and the third lens. The object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element, and the center thickness CP2 of the second spacer element, the center thickness CP2b of the second auxiliary spacer element, and the axial distance T23 from the image side surface of the second lens to the object side surface of the third lens satisfy: 0.95 ≤ (CP2 + CP2b) / T23 ≤ 1.40.

[0009] Further, the inner diameter d1s on the object side of the first spacer element, the outer diameter D1s on the object side of the first spacer element, and the effective radius DT12 of the image side surface of the first lens satisfy: 3.2 < (D1s - d1s) / DT12 < 4.1.

[0010] Further, the inner diameter d1m on the image side of the first spacer element and the curvature radius R3 of the object side surface of the second lens satisfy: -0.15 < d1m / R3 < 0.15; the inner diameter d2s on the object side of the second spacer element and the curvature radius R4 of the image side surface of the second lens satisfy: -0.7 < d2s / R4 < -0.2.

[0011] Further, the following condition is satisfied between the image-side inner diameter d1m of the first spacer element and the object-side inner diameter d2s of the second spacer element: 0.6 < d1m / d2s < 1.

[0012] Further, the spacer element group further includes a second auxiliary spacer element disposed between the second spacer element and the third lens. The object-side surface of the second auxiliary spacer element is in partial contact with the image-side surface of the second spacer element. The following conditions are satisfied between the object-side inner diameter d2s of the second spacer element and the effective focal length f2 of the second lens: 0 < d2s / f2 < 0.55; and between the image-side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens: 0.35 ≤ d2bm / f3 < 1.5.

[0013] Further, the following condition is satisfied between the inner diameter d0s of the object-side end face of the lens barrel, the object-side inner diameter d1s of the first spacer element, and the effective focal length f1 of the first lens: -2.8 < (d0s - d1s) / f1 < -1.8.

[0014] Further, the following condition is satisfied between the outer diameter D0s of the object-side end face of the lens barrel, the object-side outer diameter D1s of the first spacer element, the image-side outer diameter D1m of the first spacer element, and the object-side outer diameter D2s of the second spacer element: 0.25 < (D0s - D1s) / (D1m - D2s) ≤ 1.35.

[0015] Further, the spacer element group further includes a second auxiliary spacer element disposed between the second spacer element and the third lens. The object-side surface of the second auxiliary spacer element is in partial contact with the image-side surface of the second spacer element. The following conditions are satisfied between the image-side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens: 0.35 ≤ d2bm / f3 < 1.5; and between the object-side inner diameter d3s of the third spacer element and the effective focal length f3 of the third lens: 0.45 ≤ d3s / f3 < 0.9.

[0016] Further, the following condition is satisfied between the effective focal length f4 of the fourth lens and the image-side inner diameter d3m of the third spacer element: -0.6 < d3m / f4 < 1.1.

[0017] Further, the following condition is satisfied between the central thickness CT2 of the second lens and the central thickness CT3 of the third lens: 1.3 < CT2 / CT3 < 2.8.

[0018] Further, the following condition is satisfied between the on-axis distance T12 from the image-side surface of the first lens to the object-side surface of the second lens, the on-axis distance T23 from the image-side surface of the second lens to the object-side surface of the third lens, and the sum ∑AT of the air spaces on the optical axis between adjacent two of the first lens to the sixth lens: 0.8 < (T12 + T23) / ∑AT ≤ 0.9.

[0019] Applying the technical solution of the present invention, the optical imaging system of the present application consists of a lens barrel and six lenses and multiple spacer elements arranged in the lens barrel. By reasonably arranging the optical powers and surface shapes of the six lenses, the first lens with negative optical power and the second lens with positive optical power ensure that the absolute values of the optical powers of the front-end lenses are close, which can play a complementary role and is beneficial to achieving a large field of view. When the positions of the first spacer element to the third spacer element are set and the optical imaging system satisfies 1 < Tr1r4 / Tr5r12 < 1.2, this limitation makes the sum of the thicknesses of the first lens and the second lens equivalent to the sum of the thicknesses of the third lens to the sixth lens, resulting in relatively thick thicknesses of the first lens and the second lens at the front end. This will cause the surface shapes of the two lenses to be relatively sensitive and will greatly affect the steepness of the light rays. The steeper the light rays, the worse the field curvature, and discrete problems are likely to occur. Therefore, the present application controls d2s within a reasonable range by restricting -1.25 ≤ d2s / f12 < -0.5, making the edges of the front two lenses as gentle as possible, which is beneficial to improving the forming stability, reducing the surface shape sensitivity, and thus solving the discrete problem of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specification drawings forming a part of the present application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 Shows the dimension marking diagram of the optical imaging system of an optional embodiment of the present invention;

[0022] Figure 2 Shows the structural schematic diagram of the optical imaging system of Embodiment 1-1 of the present invention;

[0023] Figure 3 Shows the structural schematic diagram of the optical imaging system of Embodiment 1-2 of the present invention;

[0024] Figure 4 Shows the structural schematic diagram of the optical imaging system of Embodiment 1-3 of the present invention;

[0025] Figures 5 to 7 Respectively show the axial chromatic aberration curve, astigmatism curve and distortion curve of the optical imaging system of Embodiment 1 of the present invention;

[0026] Figure 8 Shows the structural schematic diagram of the optical imaging system of Embodiment 2-1 of the present invention;

[0027] Fig. 9 Shows the structural schematic diagram of the optical imaging system of Embodiment 2-2 of the present invention;

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

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

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

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

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

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

[0034] Fig. 20 An MTF defocus curve diagram of an optical imaging system according to an optional embodiment of the present invention is shown when Tr1r4 / Tr5r12=1.03 and d2s / f12=-0.72;

[0035] Fig.21 An MTF defocus curve diagram is shown when an optical imaging system of an optional embodiment of the present invention satisfies Tr1r4 / Tr5r12=1.03 and d2s / f12=-1.32;

[0036] Fig. 22 The MTF defocus curve diagram of the optical imaging system of an optional embodiment of the present invention is shown when Tr1r4 / Tr5r12=1.03 and d2s / f12=-0.2.

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

[0038] P0, lens barrel; E1, first lens; S1, object-side surface of the first lens; S2, image-side surface of the first lens; E2, second lens; S3, object-side surface of the second lens; S4, image-side surface of the second lens; E3, third lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; E4, fourth lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; E5, fifth lens; S9, object-side surface of the fifth lens; S10, image-side surface of the fifth lens; E6, sixth lens; S11, object-side surface of the sixth lens; S12, image-side surface of the sixth lens; P1, first spacer; P2, second spacer; P2b, second auxiliary spacer; P3, third spacer; P4, fourth spacer; P5, fifth spacer. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0041] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0042] 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 shape in the paraxial area can be based on the judgment method of the general knowledge in this field, and the positive and negative R value (R refers to the radius of curvature of the paraxial area, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the concave and convex. 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. In this application, the left side is the object side and the right side is the image side.

[0043] To solve the problem that the six-piece optical imaging system in the prior art has an increased thickness of the front lens to meet a large field of view, resulting in aberration, the present invention provides an optical imaging system. It should be explained here that aberration, that is, optical distortion, refers to the difference in imaging quality between the edge and the center during the imaging process due to the physical characteristics and design limitations of the lens. This difference is particularly obvious in an optical imaging system with a large field of view because the marginal rays need to pass through a thicker lens, thus increasing the degree of light scattering and refraction, resulting in inconsistent imaging quality.

[0044] As Figures 1 to 22 shown, in an alternative embodiment of the present application, the optical imaging system includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with a negative focal power, a second lens with a positive focal power, a third lens with a positive focal power, a fourth lens with a focal power, a fifth lens with a focal power, and a sixth lens with a focal power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between any two adjacent lenses among the first lens to the sixth lens; the spacer element group includes a first spacer element disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the axial distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens and the axial distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens satisfy: 1 < Tr1r4 / Tr5r12 < 1.2; the object side inner diameter d2s of the second spacer element and the combined focal length f12 of the first lens and the second lens satisfy: -1.25 ≤ d2s / f12 < -0.5.

[0045] The optical imaging system of the present application consists of a lens barrel and six lenses and multiple spacer elements arranged in the lens barrel. By reasonably arranging the optical power and surface shape of the six lenses, the first lens with negative optical power, and the second lens with positive optical power, the absolute value of the optical power of the front-end lenses is ensured to be close, which can play a complementary role and is beneficial to achieving a large field of view. When the positions of the first spacer element to the third spacer element are set and the optical imaging system satisfies 1 < Tr1r4 / Tr5r12 < 1.2, this limitation makes the sum of the thicknesses of the first lens and the second lens equivalent to the sum of the thicknesses of the third lens to the sixth lens, resulting in relatively thick thicknesses for the first lens and the second lens at the front end. This will cause the surface shapes of the two lenses to be more sensitive and will significantly affect the steepness of the light rays. The steeper the light rays, the worse the field curvature, and discrete problems are likely to occur. Therefore, in the present application, by constraining -1.25 ≤ d2s / f12 < -0.5 and controlling d2s within a reasonable range, the edges of the first two lenses are made as gentle as possible, which is beneficial to improving the forming stability, reducing the surface shape sensitivity, and thus solving the discrete problem of the system.

[0046] It should be noted that the on-axis distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens is equal to the sum of the central thickness of the first lens, the on-axis spacing distance between the first lens and the second lens, and the central thickness of the second lens. The on-axis distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens is equal to the sum of the central thickness of the third lens, the on-axis spacing distance between the third lens and the fourth lens, the central thickness of the fourth lens, the on-axis spacing distance between the fourth lens and the fifth lens, the central thickness of the fifth lens, the on-axis spacing distance between the fifth lens and the sixth lens, and the central thickness of the sixth lens.

[0047] In addition, referring to Table 1 below and Figure 20 to Figure 22 as shown, on the premise that the optical imaging system satisfies Tr1r4 / Tr5r12 = 1.03, Fig. 20 shows the MTF defocus curve graph when the optical imaging system satisfies d2s / f12 = -0.72, Fig.21 shows the MTF defocus curve graph when the optical imaging system satisfies d2s / f12 = -1.32, Fig. 22 shows the MTF defocus curve graph when the optical imaging system satisfies d2s / f12 = -0.2.

[0048] From Figure 20 to Figure 22It can be seen that when d2s / f12=-0.72 is satisfied, the defocus curve is more concentrated and the performance is better. When d2s / f12=-1.32 is satisfied, the discrete value is large, the peak drop is large, and the performance is poor. When d2s / f12=-0.2 is satisfied, the discrete value is large, the field curvature is negative, and the performance is poor. It can be seen that when d2s / f12 is in the range of -1.25 to -0.5, the MTF defocus curve of the optical imaging system performs best. Therefore, the present application can make the front-end lens as flat as possible by constraining -1.25≤d2s / f12<-0.5, which is beneficial to improving molding stability and reducing surface sensitivity. At the same time, it can ensure that the second spacing element has a reasonable coordination with the optical focal length of the front and rear lenses, which can effectively play a complementary role, which is beneficial to solving the discrete problem and ensuring the imaging quality of the optical imaging system.

[0049] Table 1

[0050]

[0051] In this embodiment, the spacer element group further includes a second auxiliary spacer element placed between the second spacer element and the third lens, and the object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element. In addition, the spacer element group further includes a fourth spacer element placed between the fourth lens and the fifth lens and in partial contact with the image side surface of the fourth lens, and a fifth spacer element placed between the fifth lens and the sixth lens and in partial contact with the image side surface of the fifth lens.

[0052] It should be noted that the optical imaging system of the present application is a flip-chip structure, that is, each lens and each spacer element is sequentially installed in the lens barrel from the object side end of the lens barrel, and the first lens to the sixth lens and the first spacer element and the fifth spacer element are sequentially installed in the lens barrel from right to left.

[0053] In this embodiment, the center thickness CP2 of the second spacer element, the center thickness CP2b of the second auxiliary spacer element, and the on-axis distance T23 from the image side surface of the second lens to the object side surface of the third lens satisfy the following: 0.95≤(CP2+CP2b) / T23≤1.40. By controlling the second spacer element and the second auxiliary spacer element, the total on-axis height of the optical imaging system can be effectively reduced, which helps to improve the assembly stability; at the same time, the edge thickness of the first lens and the second lens can be controlled to reduce the internal reflection of light and improve the imaging quality.

[0054] In this embodiment, the following relationship is satisfied among the object-side inner diameter d1s of the first spacer element, the object-side outer diameter D1s of the first spacer element, and the effective radius DT12 of the image side surface of the first lens: 3.2 < (D1s - d1s) / DT12 < 4.1. By controlling the relationship between the inner and outer diameters of the first spacer element and the effective radius of the image side surface of the first lens within a reasonable range, the assembly stability of the optical imaging system can be improved; at the same time, the head volume of the optical imaging system can be effectively controlled, which is beneficial to expanding the application range.

[0055] In this embodiment, the following relationship is satisfied between the image-side inner diameter d1m of the first spacer element and the curvature radius R3 of the object side surface of the second lens: -0.15 < d1m / R3 < 0.15; the following relationship is satisfied between the object-side inner diameter d2s of the second spacer element and the curvature radius R4 of the image side surface of the second lens: -0.7 < d2s / R4 < -0.2. By controlling these two conditional expressions, stray light can be effectively intercepted and the imaging quality can be improved; at the same time, controlling the size of the first spacer element can reduce the cost of the optical imaging system.

[0056] In this embodiment, the following relationship is satisfied between the image-side inner diameter d1m of the first spacer element and the object-side inner diameter d2s of the second spacer element: 0.6 < d1m / d2s < 1. By reasonably controlling the ratio of the image-side inner diameter of the first spacer element to the object-side inner diameter of the second spacer element within a reasonable range, the incident light can be in a divergent state from the first lens to the second lens, which can ensure the light passing amount and the imaging quality; and the first spacer element and the second spacer element are attached to the edge of the chief ray, and stray light can be intercepted as much as possible without affecting the chief ray.

[0057] In this embodiment, the object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element. The following relationship is satisfied between the object-side inner diameter d2s of the second spacer element and the effective focal length f2 of the second lens: 0 < d2s / f2 < 0.55; the following relationship is satisfied between the image-side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens: 0.35 ≤ d2bm / f3 < 1.5. By controlling these two conditional expressions, it is beneficial to control the surface type rationality of the second lens and the third lens, thereby improving the processing difficulty of the second lens and the third lens and ensuring the processing manufacturability.

[0058] In this embodiment, the following relationship is satisfied among the inner diameter d0s of the object side end surface of the lens barrel, the object-side inner diameter d1s of the first spacer element, and the effective focal length f1 of the first lens: -2.8 < (d0s - d1s) / f1 < -1.8. By controlling this conditional expression, it is beneficial to increase the field of view angle, increase the light passing amount as much as possible, and improve the imaging quality; at the same time, the head size of the optical imaging system can be controlled within a reasonable range, reducing the risk of dispersion, ensuring the imaging quality, and meeting more usage scenarios.

[0059] In this embodiment, the following relationship is satisfied among the outer diameter D0s of the object-side end face of the lens barrel, the object-side outer diameter D1s of the first spacer element, the image-side outer diameter D1m of the first spacer element, and the object-side outer diameter D2s of the second spacer element: 0.25 < (D0s - D1s) / (D1m - D2s) ≤ 1.35. By controlling this relationship, the incident light can be made to diverge from the first lens to the second lens. At the same time, the first spacer element and the second spacer element can intercept stray light as much as possible, improving the imaging quality while ensuring a large field of view.

[0060] In this embodiment, the object-side surface of the second auxiliary spacer element is in partial contact with the image-side surface of the second spacer element. The following relationship is satisfied between the image-side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens: 0.35 ≤ d2bm / f3 < 1.5; the following relationship is satisfied between the object-side inner diameter d3s of the third spacer element and the effective focal length f3 of the third lens: 0.45 ≤ d3s / f3 < 0.9. Through these two conditional expressions, the spacer elements can be made to closely adhere to the effective light rays for imaging, intercepting more stray light without affecting the passage of the effective light rays, and improving the imaging quality.

[0061] In this embodiment, the following relationship is satisfied between the effective focal length f4 of the fourth lens and the image-side inner diameter d3m of the third spacer element: -0.6 < d3m / f4 < 1.1. Through this relationship, the sizes of the third spacer element and the fourth lens can be effectively controlled, which is beneficial to reducing the size of the optical imaging system, expanding the application scenarios; at the same time, it can also reduce the cost of the optical imaging system.

[0062] In this embodiment, the following relationship is satisfied between the central thickness CT2 of the second lens and the central thickness CT3 of the third lens: 1.3 < CT2 / CT3 < 2.8. By controlling the central thicknesses of the second lens and the third lens, the total axial length of the optical imaging system can be reduced, meeting the design requirements, which is beneficial to reducing costs; at the same time, better assembly stability can be achieved.

[0063] In this embodiment, the following relationship is satisfied among the on-axis distance T12 from the image-side surface of the first lens to the object-side surface of the second lens, the on-axis distance T23 from the image-side surface of the second lens to the object-side surface of the third lens, and the sum ∑AT of the air gaps on the optical axis between any two adjacent lenses among the first lens to the sixth lens: 0.8 < (T12 + T23) / ∑AT ≤ 0.9. It should be noted that ∑AT is the sum of the air gaps on the optical axis between any two adjacent lenses among the first lens to the sixth lens. Such a setting can minimize the total axial length of the optical imaging system and reduce the overall size to meet more usage scenarios.

[0064] Optionally, the optical imaging system in the embodiments of the present application can be simulated by software and / or tools such as ZEMAX, CODEV, etc. During the simulation using the software and / or tools as described above, the surface profiles of the respective lenses can be appropriately adjusted according to the surface profiles自带 by the software and / or tools used.

[0065] In addition, in another optional embodiment of the present application, an optical imaging system is further provided, which includes a lens barrel and a lens group and a spacer element group disposed in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with optical power, a fifth lens with optical power, and a sixth lens with optical power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between any two adjacent lenses among the first lens to the sixth lens; the spacer element group includes a first spacer element disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the on-axis distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens and the on-axis distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens satisfy: 1 < Tr1r4 / Tr5r12 < 1.2; the inner diameter d0s of the object side end face of the lens barrel, the inner diameter d1s of the object side of the first spacer element, and the effective focal length f1 of the first lens satisfy: -2.8 < (d0s - d1s) / f1 < -1.8.

[0066] The optical imaging system of the present application is composed of a lens barrel, six lenses, and multiple spacer elements disposed in the lens barrel. By reasonably arranging the optical powers and surface profiles of the six lenses, the positions of the first spacer element to the third spacer element, and setting the optical imaging system to satisfy 1 < Tr1r4 / Tr5r12 < 1.2, it is beneficial to achieve a large field of view. However, this limitation makes the sum of the thicknesses of the first lens and the second lens equivalent to the sum of the thicknesses of the third lens to the sixth lens, resulting in relatively thick thicknesses of the front-end first lens and the second lens. This will cause the surface profiles of the two lenses to be more sensitive, and the edge thicknesses are relatively thick, easily resulting in a discrete problem. Therefore, by restricting -2.8 < (d0s - d1s) / f1 < -1.8, it is beneficial to increase the field of view angle, increase the light passing amount as much as possible, and improve the imaging quality; at the same time, the head size of the optical imaging system can be controlled within a reasonable range, reducing the discrete risk, ensuring the imaging quality, and meeting more usage scenarios.

[0067] Of course, other parametric expressions in the above embodiments may also be included in this embodiment, which will not be elaborated one by one here.

[0068] In addition, in another alternative embodiment of the present application, an optical imaging system is further provided, which includes a lens barrel and a lens group and a spacer element group arranged in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with an optical power, and a sixth lens with an optical power; wherein, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between two adjacent lenses among the first lens to the sixth lens; the spacer element group includes a first spacer element placed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element placed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element placed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens; the object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element. The center thickness CP2 of the second spacer element, the center thickness CP2b of the second auxiliary spacer element, and the sum ∑AT of the air gaps on the optical axis between two adjacent lenses among the first lens to the sixth lens satisfy: 0.3 < (CP2 + CP2b) / ∑AT < 0.6; the outer diameter D1m on the image side of the first spacer element, the inner diameter d1m on the image side of the first spacer element, and the curvature radius R3 of the object side surface of the second lens: -3.7 < R3 / (D1m - d1m) < 16.4.

[0069] The optical imaging system of the present application is composed of a lens barrel and six lenses and multiple spacer elements arranged in the lens barrel. By reasonably arranging the optical powers and surface types of the six lenses, the positions of the first spacer element to the third spacer element, and setting the optical imaging system to satisfy 0.3 < (CP2 + CP2b) / ∑AT < 0.6 and -3.7 < R3 / (D1m - d1m) < 16.4, it is beneficial to restrict the ratio of the sum of the center thickness of the second spacer element and the center thickness of the second auxiliary spacer element to the total sum ∑AT of the air gaps, beneficial to controlling the air gaps and lens intervals to compress the overall size, and at the same time capable of ensuring the stable cooperation between the first spacer element and the second lens, thereby ensuring the assembly stability.

[0070] Of course, other parametric expressions in the above embodiments may also be included in this embodiment, which will not be elaborated one by one here.

[0071] Optionally, the optical imaging system may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0072] The optical imaging system in the present application may use multiple lenses, such as the six lenses mentioned above. In the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. The characteristics of an aspherical lens are: the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, the aberration that occurs during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0073] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging system can be changed to obtain the various results and advantages described in this specification. For example, although six lenses are described as an example in the embodiment, the optical imaging system is not limited to including six lenses. If necessary, the optical imaging system may also include other numbers of lenses.

[0074] Figure 1 A dimension-marked schematic diagram of an optical imaging system of the present application is shown. Figure 1 Parameters such as D0s, d0s, d2m, d2s, D1m, D1s, d1m, d1s, d2bm, d3s, d3m, CP2, CP2b, and D2s are indicated in the figure to clearly and intuitively understand the meaning of the parameters. In order to facilitate the description of the optical imaging system and the surface shape of the specific lens, these parameters will no longer be reflected in the drawings when the specific embodiments are described later.

[0075] The following further describes examples of specific surface shapes and parameters of the optical imaging system applicable to the above-mentioned embodiments with reference to the accompanying drawings.

[0076] It should be noted that in the following embodiment 1, there are three examples of embodiment 1-1, embodiment 1-2, and embodiment 1-3; in embodiment 2, there are three examples of embodiment 2-1, embodiment 2-2, and embodiment 2-3; and in embodiment 3, there are three examples of embodiment 3-1, embodiment 3-2, and embodiment 3-3. In the three examples of the same embodiment, the parameters such as the radius of curvature, center thickness, and spacing distance between lenses of the optical imaging system from the first lens to the sixth lens, and the coefficients of high-order terms are the same, but the parameters such as the thickness, inner diameter, and outer diameter of the lens barrel, the first spacing element to the third spacing element, or the first spacing element to the fifth spacing element are different. In other words, the main structure for imaging is the same, but the auxiliary structure for imaging is different.

[0077] It should be noted that any one of the following examples 1 to 3 is applicable to all implementation methods of the present application.

[0078] Embodiment 1

[0079] like Figures 2 to 7 As shown, the optical imaging system of embodiment 1 is described. Figure 2 shows a schematic structural diagram of the optical imaging system of Example 1-1, Figure 3 shows a schematic structural diagram of the optical imaging system of Embodiment 1-2, Figure 4 A schematic structural diagram of the optical imaging system of Embodiments 1-3 is shown.

[0080] like Figures 2 to 4 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacing element P1, a second lens E2, a second spacing element P2, a second auxiliary spacing element P2b, a third lens E3, a third spacing element P3, a fourth lens E4, a fourth spacing element P4, a fifth lens E5, a fifth spacing element P5 and a sixth lens E6, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0081] like Figure 2 , which is a schematic diagram of the structure of the optical imaging system of Example 1-1. In this example, the object side surface and the image side surface of the first spacing element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and the image side surface of the second spacing element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface of the second auxiliary spacing element P2b, and the image side surface of the second auxiliary spacing element P2b is respectively in contact with the object side surface S5 of the third lens. The object side surface and the image side surface of the third spacing element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and the image side surface of the fourth spacing element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and the image side surface of the fifth spacing element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens.

[0082] like Figure 3 FIG. 1 is a schematic diagram of the structure of the optical imaging system of Example 1-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 1-1, and the relevant description in Example 1-1 may be referred to, and will not be repeated here.

[0083] like Figure 4 FIG. 1 is a schematic diagram of the structure of the optical imaging system of Example 1-3. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 1-1, and the relevant description in Example 1-1 may be referred to, and will not be repeated here.

[0084] In summary, the structural parameters of the optical imaging system of the first embodiment in Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3 are shown in Table 2. (Unit: mm)

[0085] Table 2

[0086]

[0087] In Embodiment 1, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a concave surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a convex surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a convex surface. The object side surface S9 of the fifth lens is a concave surface, and the image side surface S10 of the fifth lens is a convex surface. The object side surface S11 of the sixth lens is a concave surface, and the image side surface S12 of the sixth lens is a concave surface.

[0088] In Example 1, the effective focal length f1 of the first lens is -1.294 mm, the effective focal length f2 of the second lens is 4.131 mm, the effective focal length f3 of the third lens is 2.922 mm, the effective focal length f4 of the fourth lens is 1.297 mm, the effective focal length f5 of the fifth lens is -2.146 mm, and the effective focal length f6 of the sixth lens is -25.878 mm.

[0089] Table 3 shows a basic structural parameter table of the optical imaging system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0090] Table 3

[0091]

[0092] In the first embodiment, the object side surface and the image side surface of the first lens E1 to the sixth lens E6 are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0093] Formula (1)

[0094] Wherein, x is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R, that is, the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above; k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 4 below gives the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, and A26 that can be used for each aspherical mirror surface S1-S12 in Example 1.

[0095] Table 4

[0096]

[0097] Figure 5 The axial chromatic aberration curve of the optical imaging system of the first embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths after passing through the imaging lens. Figure 6 The astigmatism curve of the optical imaging system of the first embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The distortion curve of the optical imaging system of the first embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles.

[0098] according to Figures 5 to 7 It can be seen that the optical imaging system provided in the first embodiment can achieve good imaging quality.

[0099] Embodiment 2

[0100] like Figures 8 to 13 As shown, the optical imaging system of the second embodiment is described. Figure 8 shows a schematic structural diagram of the optical imaging system of Example 2-1, Fig. 9 shows a schematic structural diagram of the optical imaging system of Example 2-2, Fig.10 A schematic structural diagram of the optical imaging system of Example 2-3 is shown.

[0101] like Figures 8 to 10 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacing element P1, a second lens E2, a second spacing element P2, a second auxiliary spacing element P2b, a third lens E3, a third spacing element P3, a fourth lens E4, a fourth spacing element P4, a fifth lens E5, a fifth spacing element P5 and a sixth lens E6, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0102] like Figure 8 As shown, it is a structural schematic diagram of the optical imaging system of Example 2-1. In this example, the object side surface and image side surface of the first spacing element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and image side surface of the second spacing element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface of the second auxiliary spacing element P2b, and the image side surface of the second auxiliary spacing element P2b is respectively in contact with the object side surface S5 of the third lens. The object side surface and image side surface of the third spacing element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and image side surface of the fourth spacing element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and image side surface of the fifth spacing element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens.

[0103] like Fig. 9 FIG. 2 is a schematic diagram of the structure of the optical imaging system of Example 2-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 2-1, and the relevant description in Example 2-1 may be referred to, and will not be repeated here.

[0104] like Fig.10 , which is a schematic diagram of the structure of the optical imaging system of Example 2-3. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 2-1, and the relevant description in Example 2-1 may be referred to, and will not be repeated here.

[0105] In summary, the structural parameters of the optical imaging system of the second embodiment in Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3 are shown in Table 5. (Unit: mm)

[0106] Table 5

[0107]

[0108] In the second embodiment, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a concave surface. The object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a convex surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a convex surface. The object side surface S9 of the fifth lens is a concave surface, and the image side surface S10 of the fifth lens is a convex surface. The object side surface S11 of the sixth lens is a concave surface, and the image side surface S12 of the sixth lens is a convex surface.

[0109] In Example 2, the effective focal length f1 of the first lens is -1.290 mm, the effective focal length f2 of the second lens is 4.301 mm, the effective focal length f3 of the third lens is 2.986 mm, the effective focal length f4 of the fourth lens is 1.286 mm, the effective focal length f5 of the fifth lens is -1.685 mm, and the effective focal length f6 of the sixth lens is 8.022 mm.

[0110] Table 6 shows a basic structural parameter table of the optical imaging system of Example 2, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0111] Table 6

[0112]

[0113] Table 7 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, and A26 that can be used for the aspherical mirror surfaces S1-S12 in Example 2.

[0114] Table 7

[0115]

[0116] Fig.11 The axial chromatic aberration curve of the optical imaging system of the second embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the imaging lens. Fig.12 The astigmatism curve of the optical imaging system of the second embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.13 The distortion curve of the optical imaging system of the second embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles.

[0117] according to Figures 11 to 13 It can be seen that the optical imaging system provided in the second embodiment can achieve good imaging quality.

[0118] Embodiment 3

[0119] like Figures 14 to 19 As shown, the optical imaging system of embodiment 3 is described. Fig.14 A schematic diagram of the structure of the optical imaging system of Example 3-1 is shown, Fig.15 A schematic diagram of the structure of the optical imaging system of Example 3-2 is shown, Fig.16 A schematic structural diagram of the optical imaging system of Example 3-3 is shown.

[0120] like Figures 14 to 16 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first spacing element P1, a second lens E2, a second spacing element P2, a second auxiliary spacing element P2b, a third lens E3, a third spacing element P3, a fourth lens E4, a fourth spacing element P4, a fifth lens E5, a fifth spacing element P5 and a sixth lens E6, which are arranged in sequence in the lens barrel P0 from the object side to the image side along the optical axis.

[0121] like Fig.14 As shown, it is a structural schematic diagram of the optical imaging system of Example 3-1. In this example, the object side surface and image side surface of the first spacing element P1 are respectively in contact with the image side surface S2 of the first lens and the object side surface S3 of the second lens. The object side surface and image side surface of the second spacing element P2 are respectively in contact with the image side surface S4 of the second lens and the object side surface of the second auxiliary spacing element P2b, and the image side surface of the second auxiliary spacing element P2b is respectively in contact with the object side surface S5 of the third lens. The object side surface and image side surface of the third spacing element P3 are respectively in contact with the image side surface S6 of the third lens and the object side surface S7 of the fourth lens. The object side surface and image side surface of the fourth spacing element P4 are respectively in contact with the image side surface S8 of the fourth lens and the object side surface S9 of the fifth lens. The object side surface and image side surface of the fifth spacing element P5 are respectively in contact with the image side surface S10 of the fifth lens and the object side surface S11 of the sixth lens.

[0122] like Fig.15 FIG. 3 is a schematic diagram of the structure of the optical imaging system of Example 3-2. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

[0123] like Fig.16 FIG. 3 is a schematic diagram of the structure of the optical imaging system of Example 3-3. In this example, the supporting and abutting manner of each spacing element is the same as that of Example 3-1, and the relevant description in Example 3-1 may be referred to, and will not be repeated here.

[0124] In summary, the structural parameters of the optical imaging system of the third embodiment in the embodiments 3-1, 3-2 and 3-3 are shown in Table 8. (Unit: mm)

[0125] Table 8

[0126]

[0127] In the third embodiment, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a concave surface. The object side surface S3 of the second lens is a concave surface, and the image side surface S4 of the second lens is a convex surface. The object side surface S5 of the third lens is a convex surface, and the image side surface S6 of the third lens is a convex surface. The object side surface S7 of the fourth lens is a convex surface, and the image side surface S8 of the fourth lens is a concave surface. The object side surface S9 of the fifth lens is a convex surface, and the image side surface S10 of the fifth lens is a convex surface. The object side surface S11 of the sixth lens is a convex surface, and the image side surface S12 of the sixth lens is a concave surface.

[0128] In Example 3, the effective focal length f1 of the first lens is -1.801 mm, the effective focal length f2 of the second lens is 35.548 mm, the effective focal length f3 of the third lens is 1.889 mm, the effective focal length f4 of the fourth lens is -2.995 mm, the effective focal length f5 of the fifth lens is 1.562 mm, and the effective focal length f6 of the sixth lens is -3.726 mm.

[0129] Table 9 shows a basic structural parameter table of the optical imaging system of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters.

[0130] Table 9

[0131]

[0132] Table 10 below lists the high-order coefficients A4, A6, A8, A10, A12, A14, and A16 that can be used for the aspheric mirror surfaces S1-S12 in Example 3.

[0133] Table 10

[0134]

[0135] Fig.17 The axial chromatic aberration curve of the optical imaging system of the third embodiment is shown, which indicates the deviation of the focusing point of light of different wavelengths after passing through the imaging lens. Fig.18 The astigmatism curve of the optical imaging system of the third embodiment is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Fig.19 The distortion curve of the optical imaging system of the third embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles.

[0136] according to Figures 17 to 19 It can be seen that the optical imaging system provided in the third embodiment can achieve good imaging quality.

[0137] In summary, Embodiments 1 to 3 respectively satisfy the relationship shown in Table 11.

[0138] Table 11

[0139]

[0140] Table 12 shows parameters such as the effective focal length of each lens of the optical imaging system of Examples 1 to 3, and the total effective focal length f of the optical imaging system.

[0141] Table 12

[0142]

[0143] The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical imaging system described above.

[0144] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0145] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0146] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optical imaging system, characterized in that: It includes a lens barrel, a lens group and a spacer element group arranged in the lens barrel. The lens group is composed of six lenses. The six lenses are, in order from the object side to the image side, a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, a fourth lens with optical power, a fifth lens with optical power, and a sixth lens with optical power. Among them, the object side surface of the first lens is concave, and the image side surface is concave; the image side surface of the second lens is convex; the object side surface of the third lens is convex, and the image side surface is convex; the object side surface of the fourth lens is convex; the image side surface of the fifth lens is convex; there is an air gap between two adjacent lenses among the first lens to the sixth lens. The spacer element group includes a first spacer element placed between the first lens and the second lens and in partial contact with the image side surface of the first lens, a second spacer element placed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer element placed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens. The on-axis distance Tr1r4 from the object side surface of the first lens to the image side surface of the second lens and the on-axis distance Tr5r12 from the object side surface of the third lens to the image side surface of the sixth lens satisfy: 1 < Tr1r4 / Tr5r12 < 1.2; the object side inner diameter d2s of the second spacer element and the combined focal length f12 of the first lens and the second lens satisfy: -1.25 ≤ d2s / f12 < -0.

5.

2. The optical imaging system according to claim 1, characterized in that: The spacer element group further includes a second auxiliary spacer element placed between the second spacer element and the third lens, and the object side surface of the second auxiliary spacer element is in partial contact with the image side surface of the second spacer element. The central thickness CP2 of the second spacer element, the central thickness CP2b of the second auxiliary spacer element and the on-axis distance T23 from the image side surface of the second lens to the object side surface of the third lens satisfy: 0.95 ≤ (CP2 + CP2b) / T23 ≤ 1.

40.

3. The optical imaging system according to claim 1, characterized in that: The object side inner diameter d1s, the object side outer diameter D1s of the first spacer element and the effective radius DT12 of the image side surface of the first lens satisfy: 3.2 < (D1s - d1s) / DT12 < 4.

1.

4. The optical imaging system according to claim 1, wherein The image side inner diameter d1m of the first spacer element and the curvature radius R3 of the object side surface of the second lens satisfy: -0.15 < d1m / R3 < 0.

15. The object side inner diameter d2s of the second spacer element and the curvature radius R4 of the image side surface of the second lens satisfy: -0.7 < d2s / R4 < -0.

2.

5. The optical imaging system according to claim 1, characterized in that: The image side inner diameter d1m of the first spacer element and the object side inner diameter d2s of the second spacer element satisfy: 0.6 < d1m / d2s < 1.

6. The optical imaging system according to claim 1, characterized in that: The spacer element group further includes a second auxiliary spacer element disposed between the second spacer element and the third lens, wherein the object side surface of the second auxiliary spacer element is in contact with the image side surface of the second spacer element. The object side inner diameter d2s of the second spacer element and the effective focal length f2 of the second lens satisfy: <d2s / f2<0.55; The image-side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens satisfy the following: 0.35≤d2bm / f3<1.

5.

7. The optical imaging system according to claim 1, characterized in that: The inner diameter d0s of the object-side end surface of the lens barrel, the object-side inner diameter d1s of the first spacer element, and the effective focal length f1 of the first lens satisfy the following: -2.8<(d0s-d1s) / f1<-1.

8.

8. The optical imaging system according to claim 1, characterized in that: The outer diameter D0s of the object side end surface of the lens barrel, the object side outer diameter D1s of the first spacer element, the image side outer diameter D1m of the first spacer element and the object side outer diameter D2s of the second spacer element satisfy: 0.25<(D0s-D1s) / (D1m-D2s)≤1.

35.

9. The optical imaging system according to claim 1, characterized in that: The spacer element group further includes a second auxiliary spacer element disposed between the second spacer element and the third lens, wherein the object side surface of the second auxiliary spacer element is in contact with the image side surface of the second spacer element. The image side inner diameter d2bm of the second auxiliary spacer element and the effective focal length f3 of the third lens satisfy the following relationship: 0.35≤d2bm / f3<1.5; The object-side inner diameter d3s of the third spacing element and the effective focal length f3 of the third lens satisfy the following relationship: 0.45≤d3s / f3<0.

9.

10. The optical imaging system according to claim 1, characterized in that: The effective focal length f4 of the fourth lens and the image side inner diameter d3m of the third spacing element satisfy: -0.6 <d3m / f4<1.1。 11. The optical imaging system according to any one of claims 1 to 10, characterized in that: The center thickness CT2 of the second lens and the center thickness CT3 of the third lens satisfy: 1.3 <CT2 / CT3<2.8。 12. The optical imaging system according to any one of claims 1 to 10, characterized in that: An axial distance T12 from the image side surface of the first lens to the object side surface of the second lens, an axial distance T23 from the image side surface of the second lens to the object side surface of the third lens, and a sum ∑AT of air intervals on the optical axis between two adjacent lenses from the first lens to the sixth lens satisfy the following: 0.8<(T12+T23) / ∑AT≤0.9.

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