Optical system

Abstract

The application provides an optical system. The optical system comprises a lens barrel, a lens group and a spacer group arranged in the lens barrel, the lens group is composed of six lenses, and the lens group comprises, in sequence along the direction of the optical axis of the optical system from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -4.76<=R3 / R2<=-3.15; the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the optical axis and the maximum thickness CP2 of the second spacer in the direction of the optical axis satisfy: -11.73<=f2 / (CT2+CP2)<=-5.47. The application solves the problem of poor front end lens group stability caused by the reduction of the assembly segment difference of the front end lens in the prior art.

Description

Technical Field

[0001] This invention relates to the field of optical imaging equipment technology, and more specifically, to an optical system. Background Technology

[0002] With the development of mobile devices, optical systems are widely used in security monitoring, automotive driver assistance systems, drone photography, and various consumer electronics devices. As technology advances rapidly, manufacturers are increasingly demanding higher assembly stability from optical systems. To meet these stability requirements, the design of optical systems faces numerous challenges.

[0003] In some optical systems, the assembly step difference between adjacent lenses is reduced by controlling the radius of curvature of the adjacent lenses at the front end. This results in a significant difference in the radius of curvature between adjacent sides, leading to a large difference in the degree of light refraction when passing through adjacent sides of the lenses. Therefore, even minor deformations of the front lens during assembly can alter the light propagation path between adjacent sides, affecting optical performance. In other words, the front lens suffers from high sensitivity and poor stability.

[0004] In other words, existing optical systems suffer from poor front-end lens assembly stability due to efforts to reduce assembly stage differences. Summary of the Invention

[0005] The main objective of this invention is to provide an optical system that solves the problem of poor assembly stability of the front lens in existing optical systems, which is caused by the need to reduce the assembly stage difference of the front lens.

[0006] To achieve the above objectives, according to one aspect of the present invention, an optical system is provided, comprising a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer located between the second and third lenses and in contact with the image side surface of the second lens. The radius of curvature R3 of the object side surface of the second lens and the radius of curvature R2 of the image side surface of the first lens satisfy the following: -4.76 ≤ R3 / R2 ≤ -3.15. The effective focal length f2 of the second lens, the center thickness CT2 of the second lens along the optical axis of the optical system, and the maximum thickness CP2 of the second spacer along the optical axis satisfy the following: -11.73 ≤ f2 / (CT2+CP2) ≤ -5.47.

[0007] According to another aspect of the present invention, an optical system is provided, including a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer located between the second lens and the third lens and in contact with the image side surface of the second lens. The radius of curvature R3 of the object side surface of the second lens and the radius of curvature R2 of the image side surface of the first lens satisfy the following: -4.76≤R3 / R2≤-3.15. The radius of curvature R1 of the object side surface of the first lens, the outer diameter D0s of the object side end face of the lens barrel, and the inner diameter d0s of the object side end face of the lens barrel satisfy the following: 10.12≤R1 / (D0s-d0s)≤14.10.

[0008] According to another aspect of the present invention, an optical system is provided, comprising a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer and a third spacer. The second spacer is located between the second and third lenses and contacts the image-side surface of the second lens. The third spacer is located between the third and fourth lenses and contacts the image-side surface of the third lens. The inner diameter d2m of the image-side surface of the second spacer and the radius of curvature R6 of the image-side surface of the third lens satisfy the following: -0.89≤d2m / R6≤-0.11. The spacing distance EP23 between the image-side surface of the second spacer and the object-side surface of the third spacer in the optical axis direction and the center thickness CT3 of the third lens on the optical axis of the optical system satisfy the following: 0.76≤EP23 / CT3≤1.22.

[0009] Furthermore, the radius of curvature R1 of the object side surface of the first lens, the outer diameter D0s of the object side end face of the lens barrel, and the inner diameter d0s of the object side end face of the lens barrel satisfy the following condition: 10.12≤R1 / (D0s-d0s)≤14.10.

[0010] Furthermore, the radius of curvature R4 of the image side of the second lens, the outer diameter D2s of the object side of the second spacer, and the inner diameter d2s of the object side of the second spacer satisfy the following condition: 0.26≤R4 / (D2s-d2s)≤1.91.

[0011] Furthermore, the following conditions must be met between the distance EP02 between the object-side end face of the lens barrel and the object-side side face of the second spacer in the optical axis direction, the air gap T12 between the first lens and the second lens in the optical axis, and the combined focal length f12 of the first lens and the second lens: -3.18≤(EP02+T12) / f12≤-1.58.

[0012] Furthermore, the third lens has positive optical power, and the effective focal length f3 of the third lens, the air gap T23 between the second and third lenses on the optical axis, and the maximum thickness CP2 of the second spacer in the optical axis direction satisfy the following: 2.40≤f3 / (T23+CP2)≤10.54.

[0013] Furthermore, the object-side surface of the third lens is convex, the image-side surface of the third lens is convex, and the spacer assembly also includes a third spacer. The third spacer is located between the third lens and the fourth lens and partially contacts the image-side surface of the third lens. The radius of curvature R5 of the object-side surface of the third lens, the inner diameter d2m of the image-side surface of the second spacer, the radius of curvature R6 of the image-side surface of the third lens, and the inner diameter d3s of the object-side surface of the third spacer satisfy the following: -3.43≤(R5×d2m) / (R6×d3s)≤-0.26.

[0014] Furthermore, the third lens has positive optical power, and the spacer group also includes a third spacer. The third spacer is located between the third lens and the fourth lens and contacts the image side of the third lens. The effective focal length f3 of the third lens, the spacing distance EP23 between the image side of the second spacer and the object side of the third spacer in the optical axis direction, and the center thickness CT3 of the third lens in the optical axis satisfy the following: 0.91≤f3 / (EP23+CT3)≤1.55.

[0015] Furthermore, the object-side surface of the fourth lens is convex, and the spacer assembly also includes a third spacer. The third spacer is located between the third lens and the fourth lens and is in contact with the image-side surface of the third lens. The radius of curvature R7 of the object-side surface of the fourth lens, the outer diameter D3m of the image-side surface of the third spacer, and the inner diameter d3m of the image-side surface of the third spacer satisfy the following: 0.75≤R7 / (D3m-d3m)≤3.59.

[0016] Furthermore, the fourth lens has positive optical power, and the spacer group also includes a third spacer and a fourth spacer. The third spacer is located between the third lens and the fourth lens and contacts the image-side surface of the third lens. The fourth spacer is located between the fourth lens and the fifth lens. The effective focal length f4 of the fourth lens, the maximum thickness CP3 of the third spacer in the optical axis direction, and the distance EP34 between the image-side surface of the third spacer and the object-side surface of the fourth spacer in the optical axis direction satisfy the following: 1.37≤f4 / (CP3+EP34)≤4.53.

[0017] Furthermore, the image-side surface of the fourth lens is convex, and the spacer group also includes a fourth spacer, which is located between the fourth lens and the fifth lens. The radius of curvature R8 of the image-side surface of the fourth lens, the outer diameter D4s of the object-side surface of the fourth spacer, and the inner diameter d4s of the object-side surface of the fourth spacer satisfy the following: -2.03≤R8 / (D4s-d4s)≤-0.60.

[0018] Furthermore, the spacer assembly also includes a fourth spacer, which is located between the fourth lens and the fifth lens. The radius of curvature R9 of the object side of the fifth lens and the inner diameter d4m of the image side of the fourth spacer satisfy the following condition: 4.56≤R9 / d4m≤8.01.

[0019] Furthermore, the spacer assembly also includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth lens and the fifth lens, and the fifth spacer is located between the fifth lens and the sixth lens and is in contact with the image-side surface of the fifth lens. The air gap T45 between the fourth and fifth lenses on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, and the distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy the following: 0.59≤(T45+CT5) / EP45≤0.77.

[0020] Furthermore, the spacer group also includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth lens and the fifth lens, and the fifth spacer is located between the fifth lens and the sixth lens and is in contact with the image-side surface of the fifth lens. The effective focal length f5 of the fifth lens and the spacing distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy: -3.45≤f5 / EP45≤-2.21.

[0021] Furthermore, the spacer assembly also includes a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The inner diameter d5s of the object-side surface of the fifth spacer and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.41≤d5s / R10≤2.29.

[0022] Furthermore, the spacer assembly also includes a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The outer diameter D5m of the image-side surface of the fifth spacer and the radius of curvature R11 of the object-side surface of the sixth lens satisfy the following condition: 1.78≤D5m / R11≤2.96.

[0023] Furthermore, the spacer group includes at least a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The maximum thickness CP5 of the fifth spacer in the optical axis direction, the center thickness CT6 of the sixth lens in the optical axis, and the air gap T56 between the fifth lens and the sixth lens in the optical axis satisfy the following: 9.44≤CT6 / (T56+CP5)≤11.23.

[0024] Furthermore, the optical system satisfies at least one of the following: the first lens has negative optical power, the object-side surface of the first lens is convex, and the image-side surface of the first lens is concave; the second lens has negative optical power, the object-side surface of the second lens is concave, and the image-side surface of the second lens is concave; the fifth lens has negative optical power, the object-side surface of the fifth lens is convex, and the image-side surface of the fifth lens is concave; the sixth lens has positive optical power, the object-side surface of the sixth lens is convex, and the image-side surface of the sixth lens is convex.

[0025] According to the technical solution of this invention, the optical system includes a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer, which is located between the second lens and the third lens and contacts the image side of the second lens. The radius of curvature R3 of the object side of the second lens and the radius of curvature R2 of the image side of the first lens satisfy the following: -4.76≤R3 / R2≤-3.15. The effective focal length f2 of the second lens, the center thickness CT2 of the second lens on the optical axis of the optical system, and the maximum thickness CP2 of the second spacer on the optical axis satisfy the following: -11.73≤f2 / (CT2+CP2)≤-5.47.

[0026] The optical system of this application consists of a lens barrel, six lenses, and at least one spacer, satisfying -4.76 ≤ R3 / R2 ≤ -3.15. This indicates that the radius of curvature of the object-side surface of the second lens is larger than that of the image-side surface of the first lens, resulting in a significant difference in the light-reflecting capabilities between the two surfaces. Consequently, the first and second lenses are more sensitive to assembly misalignment, affecting the assembly stability of the optical system. Therefore, this application constrains the effective focal length f2 of the second lens, the center thickness CT2 of the second lens along the optical axis, and the maximum thickness CP2 of the second spacer along the optical axis. This ensures the refractive capability of the second lens while improving the structural strength of both the second lens and the spacer, thereby enhancing the assembly stability of the second lens, reducing deformation of the second lens, and consequently reducing changes in the air gap between the first and second lenses due to deformation. This reduces the sensitivity of the second lens and thus minimizes the impact of the front lens on the MTF peak value, ensuring the assembly stability of the optical system. In other words, the optical system of this application effectively improves the assembly stability of the optical system and reduces the sensitivity of the optical system by constraining the effective focal length of the lens, the center thickness of the lens, and the thickness of the spacer. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 A dimensioned diagram of an optical system according to an alternative embodiment of the present invention is shown;

[0029] Figure 2 A partial structural schematic diagram of the optical system of Embodiment 1-1 of the present invention is shown;

[0030] Figure 3 A partial structural schematic diagram of the optical system of Embodiments 1-2 of the present invention is shown;

[0031] Figure 4 A partial structural schematic diagram of the optical system of Embodiments 1-3 of the present invention is shown;

[0032] Figures 5 to 7 The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical system of Embodiment 1 of the present invention are shown respectively.

[0033] Figure 8 A partial structural schematic diagram of the optical system of Embodiment 2-1 of the present invention is shown;

[0034] Figure 9A partial structural schematic diagram of the optical system of Embodiment 2-2 of the present invention is shown;

[0035] Figure 10 A partial structural schematic diagram of the optical system of Embodiments 2-3 of the present invention is shown;

[0036] Figures 11 to 13 The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical system of Embodiment 2 of the present invention are shown respectively.

[0037] Figure 14 A partial structural schematic diagram of the optical system of Embodiment 3-1 of the present invention is shown;

[0038] Figure 15 A partial structural schematic diagram of the optical system of Embodiment 3-2 of the present invention is shown;

[0039] Figure 16 A partial structural schematic diagram of the optical system of Embodiment 3-3 of the present invention is shown;

[0040] Figures 17 to 19 The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical system of Embodiment 3 of the present invention are shown respectively.

[0041] Figure 20 A diagram showing the center and edge positions of the first and second lenses of an optical system according to an alternative embodiment of the present invention is provided.

[0042] The above figures include the following reference numerals:

[0043] P0, Lens tube; E1, First lens; E2, Second lens; P2, Second spacer; E3, Third lens; P3, Third spacer; E4, Fourth lens; P4, Fourth spacer; E5, Fifth lens; P5, Fifth spacer; E6, Sixth lens; S1, Object-side surface of the first lens; S2, Image-side surface of the first lens; S3, Object-side surface of the second lens; S4, Image-side surface of the second lens; S5, Object-side surface of the third lens; S6, Image-side surface of the third lens; S7, Object-side surface of the fourth lens; S8, Image-side surface of the fourth lens; S9, Object-side surface of the fifth lens; S10, Image-side surface of the fifth lens; S11, Object-side surface of the sixth lens; S12, Image-side surface of the sixth lens. Detailed Implementation

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0046] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0047] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0048] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn strictly to scale.

[0049] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface shape in the paraxial region can be determined according to the judgment method commonly known in the art, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine concavity or convexity. For the object side, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the image side, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex. In this application, the left side is the object side, and the right side is the image side.

[0050] To address the problem of poor front-end lens assembly stability caused by the effort to reduce assembly stage differences in existing optical systems, this invention provides an optical system.

[0051] like Figures 1 to 20As shown, the optical system includes a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer, which is located between the second and third lenses and contacts the image side of the second lens. The radius of curvature R3 of the object side of the second lens and the radius of curvature R2 of the image side of the first lens satisfy the following condition: -4.76≤R3 / R2≤-3.15. The effective focal length f2 of the second lens, the center thickness CT2 of the second lens on the optical axis of the optical system, and the maximum thickness CP2 of the second spacer on the optical axis satisfy the following condition: -11.73≤f2 / (CT2+CP2)≤-5.47.

[0052] The optical system of this application consists of a lens barrel, six lenses, and at least one spacer, satisfying -4.76 ≤ R3 / R2 ≤ -3.15. This indicates that the radius of curvature of the object-side surface of the second lens is larger than that of the image-side surface of the first lens, resulting in a significant difference in the light-reflecting capabilities between the two surfaces. Consequently, the first and second lenses are more sensitive to assembly misalignment. Therefore, this application constrains the effective focal length f2 of the second lens, the center thickness CT2 of the second lens along the optical axis, and the maximum thickness CP2 of the second spacer along the optical axis. This ensures the refractive capability of the second lens while improving the structural strength of both the second lens and the spacer. This improves the assembly stability of the second lens, reduces deformation of the second lens, and consequently reduces changes in the air gap between the first and second lenses due to deformation. This reduces the sensitivity of the second lens and thus the influence of the front lens on the MTF peak value, ensuring the assembly stability of the optical system. In other words, the optical system of this application effectively improves the assembly stability of the optical system and reduces the sensitivity of the optical system by constraining the effective focal length of the lens, the center thickness of the lens, and the thickness of the spacer.

[0053] Table 1 below shows the structural sensitivity simulation analysis table of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention; Table 2 shows the optical sensitivity simulation analysis table of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention; and Table 3 shows the comprehensive sensitivity simulation analysis table of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention. Specifically, the optical system of Scheme 1 of the present invention satisfies R3 / R2 = -4.12 and f2 / (CT2+CP2) = -6.25; the optical system of Example 1 satisfies R3 / R2 = -6.00 and f2 / (CT2+CP2) = -13.00; and the optical system of Example 2 satisfies R3 / R2 = -2.00 and f2 / (CT2+CP2) = -4.00.

[0054] From Table 1 and Figure 20 It is understood that when the optical systems of Scheme 1, Example 1, and Example 2 of the present invention are subjected to the same load, the simulated changes in the center and edge positions of the first and second lenses relative to the design values ​​are calculated. Specifically, the center displacement is the offset of the center position, where the center position is the intersection of the lens and the optical axis. For example, the center position of the object-side surface of the first lens is the intersection of the object-side surface of the first lens and the optical axis, and the center position of the image-side surface of the first lens is the intersection of the image-side surface of the first lens and the optical axis. The edge displacement is the offset of the edge position, where the edge position is the position of the boundary between the effective optical diameter region and the ineffective optical diameter region of the lens. For example, the edge position of the object-side surface of the first lens is the position of the boundary between the effective optical diameter region and the ineffective optical diameter region of the object-side surface of the first lens, and the edge position of the image-side surface of the first lens is the position of the boundary between the effective optical diameter region and the ineffective optical diameter region of the image-side surface of the first lens. The structural sensitivity ΔSP1 is simulated based on the change in the air gap between the first and second lenses on the optical axis. More specifically, ΔSP1 represents the structural sensitivity of the air gap between the first and second lenses on the optical axis when a certain load is applied to the optical system. When the same load is applied to the ineffective diameter region of an optical system, the force transmitted from the edge to the center of the ineffective diameter region will produce a deformation. For example, in the optical systems of Scheme 1, Example 1, and Example 2 of the present invention, the ineffective diameter region of the image-side surface of the second lens is subjected to the same external force. Under the influence of stress, deformation occurs at both the edge and center positions of the first and second lenses, which in turn causes a change in the air gap between the first and second lenses. For example, referring to Table 1, through simulation, the structural sensitivity ΔSP1 of Scheme 1, Example 1, and Example 2 of the present invention are 0.1770 μm, 1.5280 μm, and 2.3342 μm, respectively. It can be seen that the structural sensitivity ΔSP1 of the optical system of Scheme 1 of the present invention is smaller, that is, the displacement is smaller, and the structural sensitivity of the optical system of Scheme 1 of the present invention is superior.

[0055] In Table 1, the units for center displacement, edge displacement, and ΔSP1 are all micrometers (μm).

[0056]

[0057] Table 1

[0058] As shown in Table 1, the optical system of Scheme 1 of the present invention satisfies the conditions -4.76≤R3 / R2≤-3.15 and -11.73≤f2 / (CT2+CP2)≤-5.47. The optical systems of Examples 1 and 2 do not satisfy these conditions. The center displacement, edge displacement, and ΔSP1 of the optical system of Scheme 1 of the present invention are significantly smaller than those of the optical systems of Examples 1 and 2. Therefore, the assembly stability of the first and second lenses in Scheme 1 of the present invention is superior. In other words, when the values ​​of R3 / R2 and f2 / (CT2+CP2) are both within the above ranges, the change in air gap between the first and second lenses after assembly is small; conversely, when the values ​​of R3 / R2 and f2 / (CT2+CP2) are not within the above ranges, the change in air gap between the first and second lenses after assembly is large.

[0059] Table 2 shows the MTF peak drop in the simulated edge field of view (1.0F) of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention when the air gap between the first and second lenses on the optical axis changes by +1μm and -1μm, respectively. In other words, Table 2 is a simulation analysis table of the edge field of view optical sensitivity of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention with respect to the air gap between the first and second lenses on the optical axis. That is, optical sensitivity represents the MTF peak drop in the edge field of view of the optical system when the lens displacement is constant.

[0060] MTF peak value refers to the maximum value of MTF in the MTF curve. There is a theoretical MTF peak value in each field of view, while MTF peak value drop refers to the change in the MTF peak value in the MTF curve relative to the theoretical MTF peak value in that field of view.

[0061] In Table 2, the symbols “+” and “-” in +1μm and -1μm indicate the direction of fluctuation of the air gap between two adjacent lenses relative to the design value. The MTF peak value is expressed as a percentage (%) and has no unit.

[0062] Referring to Table 2, through simulation, when the air gap between the first and second lenses on the optical axis changes by +1 μm, the MTF peak drop in the edge field of view of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention is -0.3%, -0.9%, and -1.1%, respectively; when the air gap between the first and second lenses on the optical axis changes by -1 μm, the MTF peak drop in the edge field of view of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention is 0.1%, 0.5%, and -0.1%, respectively. It can be seen that the optical system of Scheme 1 of the present invention has the smallest change in the edge field of view peak drop, and the MTF peak is less affected by deformation. The optical sensitivity of the optical system of Scheme 1 of the present invention is better, and the assembly stability is better.

[0063]

[0064] Table 2

[0065] As shown in Table 1 above, the simulated structural sensitivity ΔSP1 of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention are 0.1770 μm, 1.5280 μm, and 2.3342 μm, respectively. By substituting the simulated ΔSP1 of each scheme into the optical system of their respective schemes, the change in field curvature is simulated to obtain the comprehensive sensitivity value. As shown in Table 3, through simulation, the comprehensive sensitivity of the optical systems of Scheme 1, Example 1, and Example 2 of the present invention are -0.065 μm, -0.785 μm, and -1.953 μm, respectively. It can be seen that the comprehensive sensitivity of the optical system of Scheme 1 of the present invention is the smallest, which further illustrates that the assembly stability of the optical system of Scheme 1 of the present invention is the best.

[0066]

[0067] Table 3

[0068] In summary, the optical system of Scheme 1 of the present invention exhibits less deformation under stress, and the deformation has a weaker impact on the peak MTF of the edge field of view, resulting in minimal overall sensitivity and good assembly stability.

[0069] It should be noted that this application constrains R3 / R2 and f2 / (CT2+CP2) within a reasonable range, constraining the relationship between the first lens, the second lens, and the second spacer. This ensures the stability of the first and second lens assembly, without relying on the optical power and surface shape of other lenses, which are further optimizations of the optical system based on this constraint. The other lenses can be positive or negative according to the actual design requirements of the optical system, and their surface shapes can also be convex or concave. When the optical system satisfies -4.76≤R3 / R2≤-3.15 and -11.73≤f2 / (CT2+CP2)≤-5.47, the optical system can maintain assembly stability while ensuring a reasonable step difference between the first and second lenses.

[0070] For example, in some optional embodiments, the first lens has a negative optical power, which allows more light to enter the optical system, ensuring a high light intake. In other optional embodiments, the second lens has a negative optical power, which can further diffuse the light from the first lens. In other optional embodiments, the third lens has a positive optical power, which can moderately converge the light and balance the aberrations introduced by the first and second lenses, improving the imaging quality of the optical system. In other optional embodiments, the fourth lens has a positive optical power, continuously converging the light while balancing the aberrations introduced by the previous lens group, optimizing the imaging quality. In other optional embodiments, the fifth lens has a negative optical power, reasonably diverging the light and maintaining a stable light path. In other optional embodiments, the sixth lens has a positive optical power, moderately converging the light to the imaging surface, ensuring imaging quality. In other optional embodiments, the object-side surface of the first lens is convex, and the image-side surface is concave. The object-side surface of the second lens is concave, and the image-side surface of the third lens is convex. The fourth lens has a convex object-side surface and a convex image-side surface. The fifth lens has a convex object-side surface and a concave image-side surface. The sixth lens has a convex object-side surface and a convex image-side surface. By reasonably constraining the surface shapes of each lens, it is beneficial to reasonably constrain the light path, ensure a smooth light transition, and facilitate the correction of aberrations.

[0071] In some optional embodiments, the radius of curvature R1 of the object-side surface of the first lens, the outer diameter D0s of the object-side end face of the lens barrel, and the inner diameter d0s of the object-side end face of the lens barrel satisfy the following: 10.12 ≤ R1 / (D0s-d0s) ≤ 14.10. By constraining the ratio of the radius of curvature of the object-side surface of the first lens to the difference between the outer and inner diameters of the object-side end face of the lens barrel, the wall thickness of the object-side end of the lens barrel can be controlled within a reasonable range. This ensures the structural strength of the lens barrel while maintaining a small head, thereby guaranteeing the stability of the front lens assembly within the lens barrel. With R1 / (D0s-d0s) within the above range, it avoids excessive wall thickness at the object-side end of the lens barrel, which could lead to a decrease in roundness after the inner diameter of the lens barrel shrinks during molding. This ensures a tight fit between the lens barrel and the first lens, thereby improving the assembly strength of the object-side end of the lens barrel. On the other hand, it can also avoid the structural strength of the lens barrel being reduced due to the excessive thickness of the object side end of the lens barrel, effectively reducing the deformation of the lens barrel that may occur during the assembly of the first lens, thereby preventing the first lens from being skewed during assembly, and thus significantly enhancing the stability and consistency of the optical system during the assembly process.

[0072] In some optional embodiments, the radius of curvature R4 of the image-side surface of the second lens, the outer diameter D2s of the object-side surface of the second spacer, and the inner diameter d2s of the object-side surface of the second spacer satisfy the following: 0.26 ≤ R4 / (D2s-d2s) ≤ 1.91. By constraining the ratio of the radius of curvature of the image-side surface of the second lens to the difference between the outer and inner diameters of the object-side surface of the second spacer, the range of light rays emitted from the image-side surface of the second lens can be controlled. This ensures that the path of the edge light rays emitted from the second lens is reasonable so that they can pass smoothly through the second spacer, avoiding divergence of light rays at the edge of the effective diameter of the image-side surface of the second lens. This helps reduce the risk of light leakage from the second lens, thereby significantly reducing the risk of stray light transmitted due to edge light leakage, and achieving the goal of optimizing the imaging quality of the optical system.

[0073] In some optional embodiments, the distance EP02 between the object-side end face of the lens barrel and the object-side side face of the second spacer in the optical axis direction, the air gap T12 between the first lens and the second lens in the optical axis, and the combined focal length f12 of the first lens and the second lens satisfy the following: -3.18 ≤ (EP02 + T12) / f12 ≤ -1.58. By controlling the relationship between EP02, T12, and f12, the assembly bearing difference between the first lens and the second lens can be controlled within a reasonable range, avoiding deformation of the first lens caused by excessive assembly bearing difference during assembly, effectively reducing the risk of assembly deformation of the first lens, and thus improving the assembly stability of the first lens.

[0074] In some optional embodiments, the third lens has positive optical power, and the effective focal length f3 of the third lens, the air gap T23 between the second and third lenses on the optical axis, and the maximum thickness CP2 of the second spacer in the optical axis direction satisfy the following relationship: 2.40 ≤ f3 / (T23+CP2) ≤ 10.54. By controlling the relationship between f3, T23, and CP2, the surface curvature angle of the image side of the second lens can be controlled within a reasonable range, avoiding the risk of deformation of the second lens during demolding due to excessive surface curvature angle. This effectively prevents the occurrence of excessive surface profile deviation of the image side of the second lens, thereby reducing the performance peak degradation of the optical system caused by excessive surface curvature angle, and ensuring the high performance and stability of the optical system.

[0075] In some optional embodiments, the object-side surface of the third lens is convex, the image-side surface of the third lens is convex, and the spacer assembly further includes a third spacer located between the third lens and the fourth lens and in partial contact with the image-side surface of the third lens. The radius of curvature R5 of the object-side surface of the third lens, the inner diameter d2m of the image-side surface of the second spacer, the radius of curvature R6 of the image-side surface of the third lens, and the inner diameter d3s of the object-side surface of the third spacer satisfy the following: -3.43≤(R5×d2m) / (R6×d3s)≤-0.26. By controlling (R5×d2m) / (R6×d3s) ​​within a reasonable range, the wall thickness at the junction of the effective diameter and the ineffective diameter of the third lens can be controlled, making the overall wall thickness distribution of the third lens more uniform. This avoids the problem of uneven forming shrinkage of the third lens due to the relatively thin wall thickness at the junction of the effective diameter and the ineffective diameter, significantly reducing the difficulty of surface shape adjustment of the third lens, thereby ensuring the stability of the peak performance of the optical system.

[0076] In some optional embodiments, the third lens has positive optical power, and the spacer assembly further includes a third spacer located between the third lens and the fourth lens and in contact with the image-side surface of the third lens. The effective focal length f3 of the third lens, the distance EP23 between the image-side surface of the second spacer and the object-side surface of the third spacer in the optical axis direction, and the center thickness CT3 of the third lens in the optical axis satisfy the following: 0.91≤f3 / (EP23+CT3)≤1.55. By controlling the relationship between f3, EP23, and CT3, the sag dimension of the third lens can be controlled within a reasonable range, avoiding difficulties in mold forming and demolding of the third lens due to excessively large sag dimension, reducing the difficulty of mold forming and demolding of the third lens, ensuring that the third lens can maintain a high-precision surface shape during the forming process, and significantly reducing the complexity of surface shape adjustment of the third lens.

[0077] It should be noted that the sagitta of the third lens includes the sagitta of the image-side surface of the third lens and the sagitta of the object-side surface of the third lens. The sagitta of the image-side surface of the third lens is the distance along the optical axis from the intersection of the image-side surface of the third lens and the optical axis, and the distance along the optical axis from the effective vertex of the image-side surface of the third lens.

[0078] In some optional embodiments, the object-side surface of the fourth lens is convex, and the spacer assembly further includes a third spacer located between the third and fourth lenses and in contact with the image-side surface of the third lens. The radius of curvature R7 of the object-side surface of the fourth lens, the outer diameter D3m of the image-side surface of the third spacer, and the inner diameter d3m of the image-side surface of the third spacer satisfy the following: 0.75≤R7 / (D3m-d3m)≤3.59. By controlling the ratio of the radius of curvature of the object-side surface of the fourth lens to the difference between the outer and inner diameters of the image-side surface of the third spacer, the length range of the cantilever beam of the third spacer can be controlled, avoiding the situation where the cantilever beam of the third spacer is too long, causing deformation of the third spacer during baking. This helps to ensure the stability of the relative position between the third and fourth lenses, effectively reducing the risk of aperture position shift in the optical system and maintaining the performance stability of the optical system before and after baking.

[0079] It should be noted that the spacer includes at least a first portion that contacts the adjacent optical element and a second portion that is spaced apart from the adjacent optical element. The second portion is closer to the optical axis than the first portion, and the second portion is a cantilever beam of the spacer. The length of the cantilever beam is the radial distance of the second portion. The length of the cantilever beam has a significant impact on the spacing stability of the adjacent optical elements and the reliability of the entire optical system. The optical elements include the spacer and lenses.

[0080] In some optional embodiments, the fourth lens has positive optical power. The spacer assembly further includes a third spacer and a fourth spacer. The third spacer is located between the third and fourth lenses and contacts the image-side surface of the third lens. The fourth spacer is located between the fourth and fifth lenses. The effective focal length f4 of the fourth lens, the maximum thickness CP3 of the third spacer in the optical axis direction, and the distance EP34 between the image-side surface of the third spacer and the object-side surface of the fourth spacer in the optical axis direction satisfy the following condition: 1.37 ≤ f4 / (CP3+EP34) ≤ 4.53. By constraining the relationship between f4, CP3, and EP34, the wall thickness of the spacer between the third and fifth lenses can be controlled within a reasonable range. This avoids the spacer being too thin, which would prevent it from meeting the molding and debugging requirements. It also avoids assembly deformation of the spacer between the third and fifth lenses, ensuring the stability of the assembly of the third, fourth, and fifth lenses, thereby improving the assembly stability of the optical system.

[0081] It should be noted that the fourth lens and the lens barrel are arranged radially at intervals, and a limiting spacer is provided between the outer annular surface of the fourth lens and the inner annular surface of the lens barrel. The limiting spacer is used to fix the relative position of the lens barrel and the fourth lens. The image-side surface of the limiting spacer contacts the object-side surface of the fourth spacer, and the inner annular surface of the limiting spacer contacts both the outer annular surface and the image-side surface of the fourth lens. The spacer between the third lens and the fifth lens includes at least the third spacer, the fourth spacer, and the limiting spacer.

[0082] In some optional embodiments, the image-side surface of the fourth lens is convex, and the spacer assembly further includes a fourth spacer located between the fourth and fifth lenses. The radius of curvature R8 of the image-side surface of the fourth lens, the outer diameter D4s of the object-side surface of the fourth spacer, and the inner diameter d4s of the object-side surface of the fourth spacer satisfy the following: -2.03 ≤ R8 / (D4s-d4s) ≤ -0.60. By constraining the ratio of the radius of curvature of the image-side surface of the fourth lens to the difference between the outer and inner diameters of the object-side surface of the fourth spacer, the bearing width of the fourth spacer can be controlled within a reasonable range, which is beneficial to the stable bearing between the fourth spacer and its object-side and image-side optical elements. At the same time, it can constrain the bearing width of the spacer between the third and fifth lenses and the fourth spacer, avoiding instability in the assembly of the fourth and fifth lenses indirectly caused by deformation of the fourth spacer during assembly. In addition, within a reasonable range, the constraint formula can also control the degree of deflection of light rays on the image side of the fourth lens, so as to ensure that the imaging light rays pass smoothly through the limiting spacer and the fourth spacer, and can also effectively block stray light and improve the imaging quality of the optical system.

[0083] In some optional embodiments, the spacer assembly further includes a fourth spacer located between the fourth and fifth lenses. The radius of curvature R9 of the object-side surface of the fifth lens and the inner diameter d4m of the image-side surface of the fourth spacer satisfy the following ratio: 4.56 ≤ R9 / d4m ≤ 8.01. By controlling the ratio of R9 to d4m, the influence of light reflected from the color filter of the optical system on the internal interference of the optical system can be effectively reduced, especially the light reflected from the object-side surface of the color filter that strikes the edge of the image-side surface of the fourth lens and eventually enters the fifth lens, effectively reducing the risk of stray light and maintaining the imaging quality of the optical system.

[0084] In some optional embodiments, the spacer group further includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth and fifth lenses, and the fifth spacer is located between the fifth and sixth lenses and contacts the image-side surface of the fifth lens. The air gap T45 between the fourth and fifth lenses on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, and the distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy the following: 0.59 ≤ (T45 + CT5) / EP45 ≤ 0.77. By controlling T45, CT5, and EP45, the relative uniformity of the edge thickness and center thickness of the fifth lens can be controlled, avoiding weld lines caused by poor relative uniformity of the fifth lens, thereby reducing the risk of stray light caused by weld lines of the fifth lens.

[0085] In some optional embodiments, the spacer group further includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth and fifth lenses, and the fifth spacer is located between the fifth and sixth lenses and contacts the image-side surface of the fifth lens. The effective focal length f5 of the fifth lens and the distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy the following: -3.45 ≤ f5 / EP45 ≤ -2.21. By controlling the ratio of f5 to EP45, the sag dimension of the fifth lens and the curvature angle range of the effective diameter of the fifth lens can be controlled, ensuring smooth demolding of the fifth lens during the molding process. This not only reduces the complexity and failure rate of the mold molding process but also significantly improves the molding stability of the fifth lens, ensuring the surface accuracy of the fifth lens and thus maintaining the optical performance of the optical system.

[0086] In some optional embodiments, the spacer assembly further includes a fifth spacer located between the fifth and sixth lenses and in contact with the image-side surface of the fifth lens. The inner diameter d5s of the object-side surface of the fifth spacer and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following ratio: 1.41 ≤ d5s / R10 ≤ 2.29. By controlling the ratio of d5s to R10, the edge rays of the image-side surface of the fifth lens can be controlled within a reasonable range. The fifth spacer can effectively block the internal reflected stray light from the image-side surface of the fifth lens, reducing the risk of stray light passing through the edge portion of the effective diameter of the image-side surface of the fifth lens and ensuring the imaging quality of the optical system.

[0087] In some optional embodiments, the spacer assembly further includes a fifth spacer located between the fifth and sixth lenses and in contact with the image-side surface of the fifth lens. The outer diameter D5m of the image-side surface of the fifth spacer and the radius of curvature R11 of the object-side surface of the sixth lens satisfy the following ratio: 1.78 ≤ D5m / R11 ≤ 2.96. When the image-side surface of the fifth lens and the object-side surface of the sixth lens form a snap-fit ​​structure, by controlling the ratio of D5m to R11, the fifth spacer can effectively block non-imaging light rays between the fifth and sixth lenses, preventing internal reflection stray light from the fifth lens from entering the sixth lens through the snap-fit ​​structure. This reduces the risk of stray light from the sixth lens caused by internal reflection stray light from the fifth lens, ensuring the imaging quality of the optical system.

[0088] In some optional embodiments, the spacer group includes at least a fifth spacer located between the fifth and sixth lenses and in contact with the image-side surface of the fifth lens. The maximum thickness CP5 of the fifth spacer along the optical axis, the center thickness CT6 of the sixth lens along the optical axis, and the air gap T56 between the fifth and sixth lenses along the optical axis satisfy the following: 9.44 ≤ CT6 / (T56 + CP5) ≤ 11.23. By controlling the relationship between CT6, T56, and CP5, the overall gap space between the effective diameter of the image-side surface of the fifth lens and the effective diameter of the object-side surface of the sixth lens is kept sufficient, effectively avoiding the situation where the gap between the fifth and sixth lenses is too small at any position. Even under extreme conditions of physical impact, a safe distance can be maintained between the fifth and sixth lenses, avoiding unnecessary direct contact and thus protecting the optical performance of the edge field of view of the optical system. Especially during the reliability mechanical impact test, ensuring the relative positional relationship between the fifth and sixth lenses avoids interference between them, thereby avoiding the problem of unqualified reliability verification results and effectively ensuring the reliability of the optical system.

[0089] In another alternative embodiment, an optical system is provided, including a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer located between the second and third lenses and in contact with the image side surface of the second lens. The radius of curvature R3 of the object side surface of the second lens and the radius of curvature R2 of the image side surface of the first lens satisfy the following: -4.76≤R3 / R2≤-3.15. The radius of curvature R1 of the object side surface of the first lens, the outer diameter D0s of the object side end face of the lens barrel, and the inner diameter d0s of the object side end face of the lens barrel satisfy the following: 10.12≤R1 / (D0s-d0s)≤14.10.

[0090] The optical system of this application consists of a lens barrel, six lenses, and at least one spacer, and satisfies -4.76 ≤ R3 / R2 ≤ -3.15. This indicates a significant difference in curvature between the image-side surface of the first lens and the object-side surface of the second lens, which can easily lead to step differences between the front-end lenses and affect the stability of the front-end lens assembly, especially when the lens barrel strength is poor, thus reducing the assembly stability of the front-end lenses. Therefore, this application controls the relationship between the radius of curvature R1 of the object-side surface of the first lens and the outer diameter D0s and inner diameter d0s of the object-side end face of the lens barrel. This allows control of the thickness of the object-side end of the lens barrel within a reasonable range, ensuring the structural strength of the lens barrel while maintaining a small head, thereby guaranteeing the stability of the front-end lenses assembled within the lens barrel. Within the range of R1 / (D0s-d0s), on the one hand, excessive thickness at the object-side end of the lens barrel can prevent shrinkage of the inner diameter of the lens barrel due to reduced roundness, ensuring a tight fit between the lens barrel and the first lens, thereby improving the structural strength of the object-side end of the lens barrel and ensuring the stability of the front lens support, thus improving the stability of the front lens assembly. On the other hand, it can also prevent insufficient thickness at the object-side end of the lens barrel, which would lead to a decrease in the structural strength of the lens barrel, effectively reducing the deformation that may occur during the assembly of the first lens, thereby preventing the first lens from becoming skewed during assembly, and significantly enhancing the stability and consistency of the optical system during the assembly process.

[0091] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0092] In another alternative embodiment, an optical system is provided, including a lens barrel and a lens group and a spacer group disposed within the lens barrel. The lens group consists of six lenses, including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The spacer group includes at least a second spacer and a third spacer. The second spacer is located between the second and third lenses and contacts the image-side surface of the second lens. The third spacer is located between the third and fourth lenses and contacts the image-side surface of the third lens. The inner diameter d2m of the image-side surface of the second spacer and the radius of curvature R6 of the image-side surface of the third lens satisfy the following: -0.89≤d2m / R6≤-0.11. The spacing distance EP23 between the image-side surface of the second spacer and the object-side surface of the third spacer in the optical axis direction and the center thickness CT3 of the third lens on the optical axis of the optical system satisfy the following: 0.76≤EP23 / CT3≤1.22.

[0093] The optical system of this application consists of a lens barrel, six lenses, and at least two spacers, satisfying -0.89≤d²m / R₆≤-0.11. This indicates that the inner diameter of the image-side surface of the second spacer is quite close to the radius of curvature of the image-side surface of the third lens. This necessitates a small assembly error during assembly to ensure imaging quality, especially ensuring their coaxiality. Consequently, the third lens and the second spacer are more sensitive to assembly offsets, affecting the assembly stability of the optical system. Therefore, this application, by constraining EP23 / CT3 within a reasonable range, effectively controls the difference between the center and edge thickness of the third lens. This facilitates the processing and demolding of the third lens, effectively ensuring its uniformity and structural strength, guaranteeing the bearing stability between the third lens and the second spacer, effectively reducing the risk of tilting or misalignment of the third lens after assembly, and effectively improving the assembly stability of the optical system.

[0094] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0095] Optionally, the optical system described above may also include a filter located on the object side of the imaging plane.

[0096] Optionally, the optical system may also include protective glass for protecting the photosensitive element located on the imaging surface.

[0097] It should be noted that each lens consists of an effective optical diameter region at the center and an optical structure region at the edge. The optical structure region is located on the outer periphery of the effective optical diameter region and is arranged circumferentially around it. The effective optical diameter region is used for the passage of imaging light rays, while the optical structure region is not used for the passage of imaging light rays. The optical structure region is used to contact the lens barrel, adjacent lenses, or adjacent spacers. The optical structure region is also called the non-effective optical diameter region.

[0098] The optical system in this application may employ multiple lenses, such as the six lenses described above. In this application, at least one of the mirror surfaces of each lens is an aspherical mirror surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using aspherical lenses, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality.

[0099] However, those skilled in the art will understand that the number of lenses constituting the optical system can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although six lenses have been described as an example in the embodiments, the optical system is not limited to including six lenses. If necessary, the optical system may also include other numbers of lenses.

[0100] Figure 1 A schematic diagram showing the dimensions of an optical system according to this application is provided. Figure 1 The parameters d0s, D0s, d2s, d2m, D2s, d3s, d3m, D3m, d4s, d4m, D4s, d5s, D5m, EP02, CP2, EP23, CP3, EP34, EP45, and CP5 are clearly and intuitively illustrated to provide a clear understanding of their meaning. To facilitate the description of the optical system and the specific lens profiles, these parameters will not be shown in the accompanying drawings when describing specific embodiments.

[0101] It should be noted that the object-side end face of the lens tube refers to the surface of the lens tube closest to the object side and perpendicular to the optical axis, the image-side end face of the lens tube refers to the surface of the lens tube closest to the image side and perpendicular to the optical axis, the object-side end face of the spacer refers to the surface of the spacer closest to the object side and perpendicular to the optical axis, and the image-side end face of the spacer refers to the surface of the spacer closest to the image side and perpendicular to the optical axis.

[0102] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters of the optical system applicable to the above embodiments.

[0103] It should be noted that in the following Embodiment 1, there are Embodiments 1-1, 1-2, and 1-3; in Embodiment 2, there are Embodiments 2-1, 2-2, and 2-3; and in Embodiment 3, there are Embodiments 3-1, 3-2, and 3-3. Within the same embodiment, the first to sixth lenses of the optical system have the same radius of curvature, center thickness, and other parameters, as well as the inter-lens spacing and higher-order coefficients. However, the thickness, inner diameter, and outer diameter of the lens barrel, the second to fifth spacers, and the shape of some lenses are different. In other words, the main structure used for imaging is the same, but the auxiliary structures used for imaging are different.

[0104] It should be noted that any of the embodiments described in Examples 1 to 3 below are applicable to all implementation methods of this application.

[0105] Example 1

[0106] like Figures 2 to 7 As shown, the optical system of Embodiment 1 is described. Figure 2A schematic diagram of the optical system of Embodiment 1-1 is shown. Figure 3 A schematic diagram of the optical system of Embodiments 1-2 is shown. Figure 4 A schematic diagram of the optical system of Examples 1-3 is shown.

[0107] like Figures 2 to 4 As shown, the optical system includes a lens barrel P0, six lenses and multiple spacers. The lens barrel P0 includes a first lens E1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a limiting spacer, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, and a sixth lens E6, arranged sequentially from the object side to the image side.

[0108] In this embodiment, the object side of the optical system further includes a locking cover, which has an inner ring surface and an outer ring surface. The inner ring surface of the locking cover sequentially contacts the object side surface S1 of the first lens, the object side end surface of the lens barrel P0, and the outer ring surface of the lens barrel P0 from the object side to the image side. The inner ring surface of the locking cover is serrated and engages with the outer ring surface of the lens barrel P0.

[0109] like Figure 2 The diagram shown is a schematic representation of the optical system in Embodiment 1-1. In this embodiment, the object-side and image-side of the second spacer P2 are in partial contact with the image-side S4 of the second lens and the object-side S5 of the third lens, respectively; the object-side and image-side of the third spacer P3 are in partial contact with the image-side S6 of the third lens and the object-side of the limiting spacer, respectively; the image-side of the limiting spacer is in partial contact with the object-side of the fourth spacer P4; the image-side of the fourth spacer P4 is in partial contact with the object-side S9 of the fifth lens; the object-side and image-side of the fifth spacer P5 are in partial contact with the image-side S10 of the fifth lens and the object-side S11 of the sixth lens, respectively; and the image-side S12 of the sixth lens is in partial contact with the lens barrel P0.

[0110] like Figure 3 The diagram shown is a structural schematic of the optical system of Embodiment 1-2. The bearing and contact methods of each spacer are the same as in Embodiment 1-1, and can be referred to the relevant description in Embodiment 1-1, which will not be repeated here.

[0111] like Figure 4 The diagram shown is a structural schematic of the optical system of Embodiments 1-3. The bearing and contact methods of each spacer are the same as in Embodiment 1-1, and can be referred to the relevant description in Embodiment 1-1, which will not be repeated here.

[0112] In summary, the structural parameters of the optical system of Embodiment 1 under Embodiments 1-1, 1-2, and 1-3 are shown in Table 11.

[0113] In Embodiment 1, the first lens E1 has negative optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has negative optical power, its object-side surface S3 is concave, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. In Table 4, OBJ (not shown in the figure) is the object plane of the optical system, S13 and S14 (not shown in the figure) can be the object-side and image-side surfaces of the filter or protective glass, S15 (not shown in the figure) is the imaging plane of the optical system, and STO (not shown in the figure) is the aperture stop, which is located between the third lens E3 and the fourth lens E4. That is to say, light rays from the object plane pass through S1 to S14 to reach the imaging plane S15 (not shown in the figure).

[0114] Table 4 shows the basic structural parameters of the optical system in Embodiment 1, where the units for radius of curvature and thickness are millimeters (mm).

[0115]

[0116]

[0117] Table 4

[0118] In Embodiment 1, the object-side and image-side surfaces of the first lens E1 to the third lens E3, the fifth lens E5, and the sixth lens E6 are all aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0119]

[0120] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R, i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 4 above; k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 5 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 that can be used for the aspherical mirrors S1-S6, S9-S12 in Example 1.

[0121] S1 -8.8624E-02 -6.3236E-03 1.1253E-02 -9.6124E-04 1.6603E-03 1.1855E-03 -2.4558E-04 S2 5.7801E-01 1.0707E-02 -1.4169E-02 -5.9769E-03 -1.6422E-03 -1.6680E-03 1.0192E-03 S3 5.3934E-01 -1.7354E-01 4.8346E-02 -9.9299E-03 1.8544E-03 5.8757E-05 -4.6013E-04 S4 1.5766E-01 -3.4972E-02 -2.1283E-03 3.8392E-03 -1.9829E-03 1.2128E-03 -7.1775E-04 S5 1.7285E-02 1.7734E-03 -2.2072E-04 9.1419E-05 -1.1257E-04 -1.2167E-05 -3.8534E-05 S6 3.8346E-02 2.8288E-03 2.4999E-04 6.8450E-05 -8.5601E-06 1.0691E-05 -2.4272E-05 S9 -3.5934E-01 3.6632E-02 -7.5022E-03 1.6602E-03 -5.0009E-04 9.5769E-05 -7.5857E-06 S10 -7.1069E-01 9.9821E-02 -2.5357E-02 6.2900E-03 -2.0085E-03 5.5554E-04 -1.3352E-04 S11 -4.8549E-01 3.9912E-02 -1.1354E-02 2.0288E-03 -7.2593E-04 6.5193E-05 -2.6613E-06 S12 1.1877E-01 2.8056E-02 6.6780E-03 1.3716E-04 2.0889E-04 -3.2542E-04 4.0723E-05 Face number A18 A20 A22 A24 A26 A28 A30 S1 -6.1358E-04 3.8302E-04 -7.0075E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2 4.2451E-04 3.5214E-04 -1.1232E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S3 2.2060E-04 -5.1208E-05 1.3817E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 3.2399E-04 -3.0011E-04 2.0686E-04 -1.3166E-04 1.1766E-04 -6.2517E-05 5.0871E-05 S5 -5.9410E-06 -1.1522E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 -2.3435E-05 -2.3329E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 2.2151E-05 -5.9899E-08 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 7.1321E-05 -3.0849E-05 1.1224E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 2.7356E-05 -4.5287E-06 4.6197E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S12 -8.7607E-05 5.6063E-05 -2.4697E-05 2.0559E-05 0.0000E+00 0.0000E+00 0.0000E+00

[0122] Table 5

[0123] Figure 5 The on-axis chromatic aberration curve of the optical system of Embodiment 1 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the optical system. Figure 6 The astigmatism curves of the optical system of Embodiment 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The magnification chromatic aberration curve of the optical system of Embodiment 1 is shown, which represents the deviation of light at different image heights on the imaging plane after passing through the optical system.

[0124] according to Figures 5 to 7 As can be seen, the optical system given in Example 1 can achieve good imaging quality.

[0125] Example 2

[0126] like Figures 8 to 13 As shown, the optical system of Embodiment 2 is described. Figure 8 A schematic diagram of the optical system of Embodiment 2-1 is shown. Figure 9 A schematic diagram of the optical system of Embodiment 2-2 is shown. Figure 10 A schematic diagram of the optical system of Embodiments 2-3 is shown.

[0127] like Figures 8 to 10 As shown, the optical system includes a lens barrel P0, six lenses and multiple spacers. The lens barrel P0 includes a first lens E1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a limiting spacer, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, and a sixth lens E6, arranged sequentially from the object side to the image side.

[0128] In this embodiment, the object side of the optical system further includes a locking cover, which has an inner ring surface and an outer ring surface. The inner ring surface of the locking cover sequentially contacts the object side surface S1 of the first lens, the object side end surface of the lens barrel P0, and the outer ring surface of the lens barrel P0 from the object side to the image side. The inner ring surface of the locking cover is serrated and engages with the outer ring surface of the lens barrel P0.

[0129] like Figure 8The diagram shows a schematic of the optical system in Embodiment 2-1. In this embodiment, the object-side and image-side of the second spacer P2 are in partial contact with the image-side S4 of the second lens and the object-side S5 of the third lens, respectively; the object-side and image-side of the third spacer P3 are in partial contact with the image-side S6 of the third lens and the object-side of the limiting spacer, respectively; the image-side of the limiting spacer is in partial contact with the object-side of the fourth spacer P4; the image-side of the fourth spacer P4 is in partial contact with the object-side S9 of the fifth lens; the object-side and image-side of the fifth spacer P5 are in partial contact with the image-side S10 of the fifth lens and the object-side S11 of the sixth lens, respectively; and the image-side S12 of the sixth lens is in partial contact with the lens barrel P0.

[0130] like Figure 9 The diagram shown is a structural schematic of the optical system in Embodiment 2-2. The bearing and contact methods of each spacer are the same as in Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here.

[0131] like Figure 10 The diagram shown is a structural schematic of the optical system of Embodiment 2-3. The bearing and contact methods of each spacer are the same as in Embodiment 2-1, and can be referred to the relevant description in Embodiment 2-1, which will not be repeated here.

[0132] In summary, the structural parameters of the optical system of Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 11.

[0133] In Embodiment 2, the first lens E1 has negative optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has negative optical power, its object-side surface S3 is concave, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. In Table 6, OBJ (not shown in the figure) is the object plane of the optical system, S13 and S14 (not shown in the figure) can be the object-side and image-side surfaces of the filter or protective glass, S15 (not shown in the figure) is the imaging plane of the optical system, and STO (not shown in the figure) is the aperture stop, which is located between the third lens E3 and the fourth lens E4. That is to say, light rays from the object plane pass through S1 to S14 to reach the imaging plane S15 (not shown in the figure).

[0134] Table 6 shows the basic structural parameters of the optical system in Embodiment 2, where the units for radius of curvature and thickness are millimeters (mm).

[0135] OBJ spherical endless endless S1 aspherical 11.5999 0.6000 1.55 56.0 0.0000 S2 aspherical 2.1376 3.6402 -0.9821 S3 aspherical -9.3301 0.6034 1.55 56.0 0.0000 S4 aspherical 7.1826 0.8881 0.0000 S5 aspherical 7.4047 4.0000 1.67 20.4 0.0000 S6 aspherical -36.9941 0.6377 0.0000 STO spherical endless 0.0900 S7 spherical 5.8652 1.2500 1.62 63.5 S8 spherical -7.3664 0.0900 S9 aspherical 19.0679 0.7092 1.67 20.4 0.0000 S10 aspherical 2.4925 0.1385 -0.7959 S11 aspherical 3.4915 1.5148 1.55 56.0 0.0000 S12 aspherical -3.6284 3.8266 0.0000 S13 spherical endless 0.2100 1.52 64.3 S14 spherical endless 0.5783 S15 spherical endless

[0136] Table 6

[0137] Table 7 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for the aspherical mirrors S1-S6 and S9-S12 in Example 2. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1 above.

[0138]

[0139]

[0140] Table 7

[0141] Figure 11 The on-axis chromatic aberration curve of the optical system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical system. Figure 12 The astigmatism curves of the optical system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 13 The magnification chromatic aberration curve of the optical system of Embodiment 2 is shown, which represents the deviation of light at different image heights on the imaging plane after passing through the optical system.

[0142] according to Figures 11 to 13 It can be seen that the optical system given in Example 2 can achieve good imaging quality.

[0143] Example 3

[0144] like Figures 14 to 19 As shown, the optical system of Embodiment 3 is described. Figure 14 A schematic diagram of the optical system of Embodiment 3-1 is shown. Figure 15 A schematic diagram of the optical system of Embodiment 3-2 is shown. Figure 16 A schematic diagram of the optical system of Embodiment 3-3 is shown.

[0145] like Figures 14 to 16 As shown, the optical system includes a lens barrel P0, six lenses, and multiple spacers. The lens barrel P0 includes a first lens E1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a third auxiliary spacer, a limiting spacer, a fourth lens E4, a fourth spacer P4, a fifth lens E5, a fifth spacer P5, and a sixth lens E6, arranged sequentially from the object side to the image side.

[0146] In this embodiment, the object side of the optical system further includes a locking cover, which has an inner ring surface and an outer ring surface. The inner ring surface of the locking cover sequentially contacts the object side surface S1 of the first lens, the object side end surface of the lens barrel P0, and the outer ring surface of the lens barrel P0 from the object side to the image side. The inner ring surface of the locking cover is serrated and engages with the outer ring surface of the lens barrel P0.

[0147] like Figure 14 The diagram shown is a schematic representation of the optical system in Embodiment 3-1. In this embodiment, the object-side and image-side of the second spacer P2 are in partial contact with the image-side S4 of the second lens and the object-side S5 of the third lens, respectively; the object-side and image-side of the third spacer P3 are in partial contact with the image-side S6 of the third lens and the object-side of the third auxiliary spacer, respectively; the image-side of the third auxiliary spacer is in partial contact with the object-side of the limiting spacer; the image-side of the limiting spacer is in partial contact with the object-side of the fourth spacer P4; the image-side of the fourth spacer P4 is in partial contact with the object-side S9 of the fifth lens; the object-side and image-side of the fifth spacer P5 are in partial contact with the image-side S10 of the fifth lens and the object-side S11 of the sixth lens, respectively; and the image-side S12 of the sixth lens is in partial contact with the lens barrel P0.

[0148] like Figure 15 The diagram shown is a structural schematic of the optical system in Embodiment 3-2. The bearing and contact methods of each spacer are the same as in Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here.

[0149] like Figure 16 The diagram shown is a structural schematic of the optical system in Embodiment 3-3. The bearing and contact methods of each spacer are the same as in Embodiment 3-1, and can be referred to the relevant description in Embodiment 3-1, which will not be repeated here.

[0150] In summary, the structural parameters of the optical system of Embodiment 3 under Embodiments 3-1, 3-2, and 3-3 are shown in Table 11.

[0151] In Embodiment 3, the first lens E1 has negative optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has negative optical power, its object-side surface S3 is concave, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is convex. The fourth lens E4 has positive optical power, its object-side surface S7 is convex, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The sixth lens E6 has positive optical power, its object-side surface S11 is convex, and its image-side surface S12 is convex. In Table 8, OBJ (not shown in the figure) is the object plane of the optical system, S13 and S14 (not shown in the figure) can be the object-side and image-side surfaces of the filter or protective glass, S15 (not shown in the figure) is the imaging plane of the optical system, and STO (not shown in the figure) is the aperture stop, which is located between the third lens E3 and the fourth lens E4. That is to say, light rays from the object plane pass through S1 to S14 to reach the imaging plane S15 (not shown in the figure).

[0152] Table 8 shows the basic structural parameters of the optical system in Embodiment 3, where the units for radius of curvature and thickness are millimeters (mm).

[0153] OBJ spherical endless endless S1 aspherical 16.1620 2.1425 1.55 56.0 -98.9449 S2 aspherical 3.9156 1.1874 0.1164 S3 aspherical -18.6446 0.6000 1.54 55.7 -98.8866 S4 aspherical 3.4309 2.7180 -0.6136 S5 aspherical 6.3843 3.9988 1.55 56.0 -3.5114 S6 aspherical -6.4649 1.8780 -1.5561 STO spherical endless 0.0906 S7 spherical 7.7448 1.3903 1.62 63.5 S8 spherical -5.8414 0.5563 S9 aspherical 26.6024 0.6000 1.67 20.4 79.9831 S10 aspherical 2.5512 0.1011 -0.9805 S11 aspherical 3.1442 1.1922 1.55 56.0 -0.7606 S12 aspherical -26.3611 1.7104 -99.0000 S13 spherical endless 0.2100 1.52 64.3 S14 spherical endless 1.5302 S15 spherical endless

[0154] Table 8

[0155] Table 9 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 that can be used for the aspherical mirrors S1-S6 and S9-S12 in Example 3. The surface shape of each aspherical surface can be defined by formula (1) given in Example 1 above.

[0156] S1 -2.4127E-01 -1.8254E-02 1.8560E-02 -2.8806E-03 -4.1377E-03 1.7772E-03 1.8673E-03 S2 -1.2273E-01 6.7126E-02 -3.3287E-02 1.8327E-02 -2.7469E-04 -5.1971E-03 -8.5621E-03 S3 1.7138E+00 -2.8703E-01 1.2206E-01 -2.1017E-02 1.5002E-02 -1.1500E-02 1.1564E-03 S4 8.9862E-01 -1.7259E-01 6.8540E-02 -2.4210E-03 5.8299E-03 -3.7984E-04 -8.5449E-04 S5 2.8508E-02 2.8193E-02 1.0819E-02 1.5495E-03 -2.8199E-04 -1.2907E-04 -8.2473E-05 S6 2.0398E-02 4.7250E-03 1.4927E-03 2.7326E-04 9.0502E-05 3.2526E-05 1.2953E-05 S9 -1.3184E-01 1.2909E-02 -2.6310E-03 4.2921E-04 7.3522E-05 -7.4264E-05 8.5892E-05 S10 -2.7221E-01 3.7345E-02 -6.6056E-03 4.8691E-04 5.8503E-04 -4.6410E-04 3.0703E-04 S11 -1.7543E-01 2.6136E-02 -2.7903E-03 -1.6187E-03 1.0638E-03 -9.2123E-04 3.9193E-04 S12 2.0813E-01 -7.8098E-03 4.5863E-03 -2.7165E-03 -3.2119E-04 -1.9716E-04 -1.6418E-04 Face number A18 A20 A22 A24 A26 A28 A30 S1 -1.9191E-03 7.5883E-04 -9.3644E-05 -7.6616E-05 3.6799E-05 0.0000E+00 0.0000E+00 S2 -4.4693E-04 -1.3797E-03 4.3699E-04 -1.9890E-05 5.0985E-04 0.0000E+00 0.0000E+00 S3 1.2787E-04 -5.4304E-04 7.9584E-04 -3.7436E-04 1.2466E-04 0.0000E+00 0.0000E+00 S4 1.0778E-03 -9.3256E-04 6.1142E-04 -3.5400E-04 0.0000E+00 0.0000E+00 0.0000E+00 S5 8.6756E-05 -3.3818E-05 2.6200E-05 -2.3619E-05 4.2124E-06 0.0000E+00 0.0000E+00 S6 1.5403E-06 -3.1803E-06 1.2020E-06 -5.9549E-08 -8.7185E-08 0.0000E+00 0.0000E+00 S9 -4.6993E-05 1.9187E-05 1.1431E-06 2.0754E-06 -1.6038E-06 0.0000E+00 0.0000E+00 S10 -1.4894E-04 6.6971E-05 -1.9807E-05 1.2013E-05 -4.3440E-06 0.0000E+00 0.0000E+00 S11 -2.7340E-04 1.0779E-04 -6.2825E-05 1.4217E-05 -1.8629E-05 0.0000E+00 0.0000E+00 S12 -6.5694E-05 -4.9651E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0157] Table 9

[0158] Figure 17 The on-axis chromatic aberration curve of the optical system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical system. Figure 18 The astigmatism curves of the optical system of Embodiment 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 19 The magnification chromatic aberration curve of the optical system of Embodiment 3 is shown, which represents the deviation of light at different image heights on the imaging plane after passing through the optical system.

[0159] according to Figures 17 to 19As can be seen, the optical system given in Example 3 can achieve good imaging quality.

[0160] In summary, the optical systems of Examples 1 to 3 respectively satisfy the relationships shown in Table 10.

[0161]

[0162]

[0163] Table 10

[0164] Table 11 shows some parameters (unit: mm) of the optical systems of Embodiments 1 to 3. In Table 11 below, f is the effective focal length of the optical system, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, f4 is the effective focal length of the fourth lens, f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f12 is the combined focal length of the first and second lenses.

[0165] d0s 15.000 15.000 15.000 15.600 15.600 15.600 15.922 15.922 15.922 D0s 16.088 16.088 16.088 16.746 16.746 16.746 17.068 17.068 17.068 d2s 4.324 4.904 4.233 4.354 4.254 4.157 5.577 5.777 5.377 d2m 4.324 4.904 4.233 4.354 4.254 4.157 5.577 5.777 5.377 D2s 13.800 13.600 14.000 8.122 13.600 12.600 11.800 11.400 10.800 d3s 3.484 3.484 3.484 3.191 3.191 3.191 6.361 6.456 6.645 d3m 3.484 3.484 3.484 3.191 3.191 3.191 5.866 5.866 5.866 D3m 7.158 11.200 11.400 6.865 11.007 10.600 8.056 8.434 9.056 d4s 4.056 4.344 3.836 3.166 3.053 3.123 3.506 3.466 3.322 d4m 4.056 4.344 3.836 3.166 3.053 3.123 3.506 3.466 3.322 D4s 7.000 10.400 10.600 6.803 10.000 10.377 6.800 9.000 9.800 d5s 4.822 5.040 4.673 3.692 3.834 3.520 4.360 4.194 4.250 D5m 6.740 9.200 10.200 6.203 9.000 6.805 6.600 8.800 6.400 EP02 2.963 3.158 2.918 3.517 3.417 3.488 6.062 6.162 5.796 CP2 0.022 0.022 0.022 0.022 0.022 0.022 0.030 0.030 0.030 EP23 4.251 4.056 4.296 4.376 4.476 4.405 3.250 3.050 3.216 CP3 0.030 0.030 0.030 0.030 0.030 0.030 2.250 2.350 2.550 EP34 1.718 1.646 1.546 1.317 1.244 1.177 1.836 1.738 1.381 EP45 1.560 1.699 1.691 1.266 1.356 1.363 1.497 1.520 1.901 CP5 0.022 0.022 0.022 0.022 0.022 0.022 0.022 0.022 0.022 f1 -25.32 -25.32 -25.32 -4.91 -4.91 -4.91 -10.08 -10.08 -10.08 f2 -4.11 -4.11 -4.11 -7.33 -7.33 -7.33 -5.35 -5.35 -5.35 f3 11.76 11.76 11.76 9.59 9.59 9.59 6.61 6.61 6.61 f4 5.19 5.19 5.19 5.47 5.47 5.47 5.59 5.59 5.59 f5 -3.76 -3.76 -3.76 -4.37 -4.37 -4.37 -4.27 -4.27 -4.27 f6 3.93 3.93 3.93 3.52 3.52 3.52 5.22 5.22 5.22 f12 -3.28 -3.28 -3.28 -2.25 -2.25 -2.25 -3.27 -3.27 -3.27

[0166] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical system described above.

[0167] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0168] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0169] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0170] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optical system, characterized in that, Includes a lens barrel and a lens assembly and spacer assembly disposed within the lens barrel. The lens group consists of six lenses with optical power. The lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side along the optical axis of the optical system. The first lens has negative optical power, and its object side is convex and its image side is concave. The second lens has negative optical power, and its object side is concave and its image side is concave. The third lens has positive optical power, and its object side is convex and its image side is convex. The fourth lens has positive optical power, and its object side is convex and its image side is convex. The fifth lens has negative optical power, and its object side is convex and its image side is concave. The sixth lens has positive optical power, and its object side is convex and its image side is convex. The spacer assembly includes at least a second spacer, which is located between the second lens and the third lens and contacts the image-side surface of the second lens; The radius of curvature R3 of the object side of the second lens and the radius of curvature R2 of the image side of the first lens satisfy the following condition: -4.76 ≤ R3 / R2 ≤ -3.15; The effective focal length f2 of the second lens, the center thickness CT2 of the second lens on the optical axis of the optical system, and the maximum thickness CP2 of the second spacer in the direction of the optical axis satisfy the following: -11.73≤f2 / (CT2+CP2)≤-5.

47.

2. The optical system according to claim 1, characterized in that, The radius of curvature R1 of the object side surface of the first lens, the outer diameter D0s of the object side end face of the lens barrel, and the inner diameter d0s of the object side end face of the lens barrel satisfy the following condition: 10.12≤R1 / (D0s-d0s)≤14.

10.

3. The optical system according to claim 1, characterized in that, The radius of curvature R4 of the image side of the second lens, the outer diameter D2s of the object side of the second spacer, and the inner diameter d2s of the object side of the second spacer satisfy the following condition: 0.26≤R4 / (D2s-d2s)≤1.

91.

4. The optical system according to claim 1, characterized in that, The following conditions must be met between the object-side end face of the lens barrel and the object-side side face of the second spacer in the optical axis direction, the air gap T12 between the first lens and the second lens in the optical axis, and the combined focal length f12 of the first lens and the second lens: -3.18≤(EP02+T12) / f12≤-1.

58.

5. The optical system according to claim 1, characterized in that, The effective focal length f3 of the third lens, the air gap T23 between the second lens and the third lens on the optical axis, and the maximum thickness CP2 of the second spacer in the optical axis direction satisfy the following condition: 2.40≤f3 / (T23+CP2)≤10.

54.

6. The optical system according to claim 1, characterized in that, The spacer assembly further includes a third spacer, which is located between the third lens and the fourth lens and contacts the image-side surface of the third lens. The radius of curvature R5 of the object-side surface of the third lens, the inner diameter d2m of the image-side surface of the second spacer, the radius of curvature R6 of the image-side surface of the third lens, and the inner diameter d3s of the object-side surface of the third spacer satisfy the following: -3.43≤(R5×d2m) / (R6×d3s)≤-0.

26.

7. The optical system according to claim 1, characterized in that, The spacer group further includes a third spacer, which is located between the third lens and the fourth lens and contacts the image-side surface of the third lens. The effective focal length f3 of the third lens, the spacing distance EP23 between the image-side surface of the second spacer and the object-side surface of the third spacer in the optical axis direction, and the center thickness CT3 of the third lens in the optical axis satisfy the following: 0.91≤f3 / (EP23+CT3)≤1.

55.

8. The optical system according to claim 1, characterized in that, The spacer assembly further includes a third spacer, which is located between the third lens and the fourth lens and contacts the image-side surface of the third lens. The radius of curvature R7 of the object-side surface of the fourth lens, the outer diameter D3m of the image-side surface of the third spacer, and the inner diameter d3m of the image-side surface of the third spacer satisfy the following: 0.75≤R7 / (D3m-d3m)≤3.

59.

9. The optical system according to claim 1, characterized in that, The spacer group further includes a third spacer and a fourth spacer. The third spacer is located between the third lens and the fourth lens and contacts the image-side surface of the third lens. The fourth spacer is located between the fourth lens and the fifth lens. The effective focal length f4 of the fourth lens, the maximum thickness CP3 of the third spacer in the optical axis direction, and the spacing distance EP34 between the image-side surface of the third spacer and the object-side surface of the fourth spacer in the optical axis direction satisfy the following: 1.37≤f4 / (CP3+EP34)≤4.

53.

10. The optical system according to claim 1, characterized in that, The spacer group further includes a fourth spacer located between the fourth lens and the fifth lens. The radius of curvature R8 of the image side of the fourth lens, the outer diameter D4s of the object side of the fourth spacer, and the inner diameter d4s of the object side of the fourth spacer satisfy the following: -2.03≤R8 / (D4s-d4s)≤-0.

60.

11. The optical system according to claim 1, characterized in that, The spacer group further includes a fourth spacer, which is located between the fourth lens and the fifth lens. The radius of curvature R9 of the object side of the fifth lens and the inner diameter d4m of the image side of the fourth spacer satisfy the following condition: 4.56≤R9 / d4m≤8.

01.

12. The optical system according to any one of claims 1 to 11, characterized in that, The spacer group further includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth lens and the fifth lens, and the fifth spacer is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The air gap T45 between the fourth lens and the fifth lens on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, and the distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy the following: 0.59≤(T45+CT5) / EP45≤0.

77.

13. The optical system according to any one of claims 1 to 11, characterized in that, The spacer group further includes a fourth spacer and a fifth spacer. The fourth spacer is located between the fourth lens and the fifth lens, and the fifth spacer is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The effective focal length f5 of the fifth lens and the spacing distance EP45 between the image-side surface of the fourth spacer and the object-side surface of the fifth spacer in the optical axis direction satisfy the following: -3.45≤f5 / EP45≤-2.

21.

14. The optical system according to any one of claims 1 to 11, characterized in that, The spacer group further includes a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The inner diameter d5s of the object-side surface of the fifth spacer and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.41≤d5s / R10≤2.

29.

15. The optical system according to any one of claims 1 to 11, characterized in that, The spacer assembly further includes a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The outer diameter D5m of the image-side surface of the fifth spacer and the radius of curvature R11 of the object-side surface of the sixth lens satisfy the following condition: 1.78≤D5m / R11≤2.

96.

16. The optical system according to any one of claims 1 to 11, characterized in that, The spacer group includes at least a fifth spacer, which is located between the fifth lens and the sixth lens and contacts the image-side surface of the fifth lens. The maximum thickness CP5 of the fifth spacer in the optical axis direction, the center thickness CT6 of the sixth lens in the optical axis, and the air gap T56 between the fifth lens and the sixth lens in the optical axis satisfy the following: 9.44≤CT6 / (T56+CP5)≤11.23.

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