Optical system

Abstract

Provided is an optical system including: a lens group including, in order from an object side of the optical system to an image side of the optical system, first to fifth lenses; in the plurality of spacers, the spacers located between the third lens and the fourth lens and at least partially in contact with the image side surface of the third lens are third spacers, and the spacers located between the fourth lens and the fifth lens and at least partially in contact with the image side surface of the fourth lens are fourth spacers; a lens barrel having an accommodation space in which the lens group and the plurality of spacers are accommodated; an air interval T34 between the third lens and the fourth lens on the optical axis and an air interval T45 between the fourth lens and the fifth lens on the optical axis meet the condition that T45 / T34 is greater than or equal to 4.9 and less than or equal to 6.99; the center thickness CT4 of the fourth lens on the optical axis and the spacing distance EP34 between the third spacer and the fourth spacer in the direction of the optical axis meet the condition that CT4 / EP34 is larger than or equal to 1.47 and smaller than or equal to 2.03. According to the invention, the problem of divergence of an out-of-focus curve of an optical system in the prior art is solved.

Description

Technical Field

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

[0002] Driven by technology, optical technology is becoming increasingly integrated into everyday life. Optical systems responsible for capturing images are crucial in fields such as security, automotive, drones, and consumer electronics. To correct for off-axis aberrations, the shape and arrangement of the rear-end lenses in traditional five-element optical systems are limited. However, this results in excessive light deflection at the edges of the rear end, affecting the smoothness and focus curve, which in turn compromises the imaging performance of the optical system. Furthermore, the processability of these lenses under these extreme designs is poor, hindering the widespread adoption of five-element optical systems. Therefore, adjusting the shape and position of the rear-end lenses and spacers to improve the performance of the focus curve is a pressing issue. Summary of the Invention

[0003] The main purpose of the present invention is to provide an optical system to solve the problem of divergence of the defocus curve of the optical system in the prior art.

[0004] To achieve the above-mentioned object, according to one aspect of the present invention, there is provided an optical system, comprising: a lens group, the lens group comprising five lenses having optical power, the lens group comprising, in order from the object side to the image side of the optical system, a first lens to a fifth lens; a plurality of spacers, wherein the third spacer is located between the third lens and the fourth lens and at least partially contacts the image side surface of the third lens, and the fourth spacer is located between the fourth lens and the fifth lens and at least partially contacts the image side surface of the fourth lens; and a lens barrel having a receiving space, the lens group and the plurality of spacers being accommodated in the receiving space; wherein an air spacing T34 on the optical axis of the optical system between the third lens and the fourth lens and an air spacing T45 on the optical axis between the fourth lens and the fifth lens satisfy the following conditions: 4.9≤T45 / T34≤6.99; and a center thickness CT4 of the fourth lens on the optical axis and an interval EP34 between the third and fourth spacers along the optical axis satisfy the following conditions: 1.47≤CT4 / EP34≤2.03.

[0005] According to another aspect of the present invention, an optical system is provided, comprising: a lens group, the lens group comprising five lenses having optical power, the lens group comprising, in order from the object side to the image side of the optical system, a first lens to a fifth lens; a plurality of spacers, wherein the third spacer is located between the third lens and the fourth lens and is in at least partial contact with the image side surface of the third lens, and the fourth spacer is located between the fourth lens and the fifth lens and is in at least partial contact with the image side surface of the fourth lens; a lens barrel, the lens barrel having a receiving space, the lens group and the plurality of spacers being accommodated in the receiving space; wherein an air gap T34 between the third lens and the fourth lens on the optical axis of the optical system and an air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy the following: 4.9≤T45 / T34≤6.99; and an outer diameter D4s of the object side surface of the fourth spacer and a curvature radius R8 of the image side surface of the fourth lens satisfy the following: -2.83≤D4s / R8≤-2.39.

[0006] Furthermore, among the multiple spacers, the first spacer is located between the first lens and the second lens and is in at least partial contact with the image side surface of the first lens, and the curvature radius R1 of the object side surface of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the inner diameter d1s of the object side surface of the first spacer satisfy the following: 2.83≤R1 / (d0s-d1s)≤3.78.

[0007] Furthermore, among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens. The effective focal length f1 of the first lens, the spacing distance EP01 from the object side end surface of the lens barrel to the object side surface of the first spacer along the optical axis, and the center thickness CT1 of the first lens on the optical axis satisfy the following: -4.87≤f1 / (EP01+CT1)≤-2.93.

[0008] Furthermore, among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens, and the curvature radius R2 of the image side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer, and the inner diameter d1s of the object side surface of the first spacer satisfy the following: 0.67≤R2 / (D1s-d1s)≤1.39.

[0009] Furthermore, among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens, and the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens. The effective focal length f2 of the second lens, the air gap T12 between the first lens and the second lens on the optical axis, and the spacing distance EP12 between the first spacer and the second spacer along the optical axis satisfy the following: 1.29≤f2 / (T12+EP12)≤2.83.

[0010] Furthermore, among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens, and the curvature radius R3 of the object side surface of the second lens, the center thickness CT2 of the second lens on the optical axis, and the inner diameter d2s of the object side surface of the second spacer satisfy the following: 0.99 mm ≤ R3 × CT2 / d2s ≤ 1.72 mm.

[0011] Furthermore, among the multiple spacers, the second spacer is located between the second lens and the third lens and at least partially in contact with the image side surface of the second lens, and the curvature radius R4 of the image side surface of the second lens and the outer diameter D2s of the object side surface of the second spacer satisfy the following relationship: -2.07≤R4 / D2s≤-0.37.

[0012] Furthermore, among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens, and the center thickness CT2 of the second lens on the optical axis, 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 satisfy the following: 6.01≤CT2 / (T23+CP2)≤6.29.

[0013] Furthermore, among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens, and the curvature radius R5 of the object side surface of the third lens and the outer diameter D2m of the image side surface of the second spacer and the inner diameter d2m of the image side surface of the second spacer satisfy the following relationship: 0.77≤R5 / (D2m-d2m)≤3.48.

[0014] Furthermore, among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens. The spacing distance EP23 between the second spacer and the third spacer along the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 1.72≤EP23 / CT3≤2.06.

[0015] Furthermore, an outer diameter D3s of the object-side surface of the third spacer, an inner diameter d3s of the object-side surface of the third spacer, and a curvature radius R6 of the image-side surface of the third lens satisfy the following relationship: 1.09≤(D3s-d3s) / R6≤1.50.

[0016] Furthermore, an outer diameter D3m of the image-side surface of the third spacer and a curvature radius R7 of the object-side surface of the fourth lens satisfy the following relationship: 0.95≤D3m / R7≤2.69.

[0017] Furthermore, an outer diameter D4s of the object-side surface of the fourth spacer and a curvature radius R8 of the image-side surface of the fourth lens satisfy the following relationship: -2.83≤D4s / R8≤-2.39.

[0018] Furthermore, an outer diameter D4m of the image-side surface of the fourth spacer, an inner diameter d4m of the image-side surface of the fourth spacer, and a curvature radius R9 of the object-side surface of the fifth lens satisfy: -1.83≤(D4m-d4m) / R9≤-1.41.

[0019] Furthermore, 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 positive optical power, the object side surface of the second lens is convex, and the image side surface of the second lens is convex; the third lens has negative optical power, the object side surface of the third lens is convex, and the image side surface of the third lens is concave; the fourth lens has positive optical power, the object side surface of the fourth lens is convex, and the image side surface of the fourth lens is convex; the fifth lens has negative optical power, the object side surface of the fifth lens is concave, and the image side surface of the fifth lens is concave.

[0020] According to the technical solution of the present invention, an optical system includes a lens group, a plurality of spacers, and a lens barrel. The lens group includes five lenses with optical power, and the lens group includes, in order from the object side to the image side of the optical system, a first lens to a fifth lens. Among the plurality of spacers, a third spacer is located between the third lens and the fourth lens and is in at least partial contact with the image side surface of the third lens, and a fourth spacer is located between the fourth lens and the fifth lens and is in at least partial contact with the image side surface of the fourth lens. The lens barrel has a receiving space, and the lens group and the plurality of spacers are accommodated in the receiving space. The air spacing T34 between the third lens and the fourth lens on the optical axis of the optical system and the air spacing T45 between the fourth lens and the fifth lens on the optical axis satisfy the following conditions: 4.9≤T45 / T34≤6.99. The center thickness CT4 of the fourth lens on the optical axis and the spacing distance EP34 between the third spacer and the fourth spacer along the optical axis satisfy the following conditions: 1.47≤CT4 / EP34≤2.03.

[0021] To balance the Petzval field curvature of the optical system, the surface curvature of the fourth and fifth lenses of the five-element optical system of this application is relatively large. This results in the air spacing between the fourth and fifth lenses on the optical axis being larger than the air spacing between the fourth and third lenses on the optical axis, and satisfies the condition 4.9≤T45 / T34≤6.99, making the fourth lens more sensitive during assembly. By controlling the ratio of the center thickness of the fourth lens on the optical axis to the spacing distance between the third and fourth spacers, this application indirectly controls the shape and thickness of the effective diameter and mechanical parts of the fourth lens, thereby limiting the refraction angle of light when passing through the third and fourth lenses, improving the concentration of the optical system's defocus curve, and simultaneously avoiding the shape of the fourth lens being at an extreme design limit, improving the processability of the fourth lens, reducing assembly sensitivity, and achieving a better defocus transfer function performance for the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 A schematic diagram showing some parameters of an optical system according to any optional embodiment of the present invention;

[0024] Figure 2 FIG2 shows a schematic structural diagram of an optical system according to a first embodiment of the present invention;

[0025] Figure 3 shows an axial chromatic aberration curve of the optical system of Example 1 of the present invention;

[0026] Figure 4 shows an astigmatism curve of the optical system according to the first embodiment of the present invention;

[0027] Figure 5 shows a magnification chromatic aberration curve of the optical system of Example 1 of the present invention;

[0028] Figure 6 FIG2 shows a schematic structural diagram of an optical system according to a second embodiment of the present invention;

[0029] Figure 7 FIG2 shows a schematic structural diagram of an optical system according to a third embodiment of the present invention;

[0030] Figure 8 FIG2 shows a schematic structural diagram of an optical system according to a fourth embodiment of the present invention;

[0031] Figure 9 shows an axial chromatic aberration curve of the optical system of the fourth embodiment of the present invention;

[0032] Figure 10shows an astigmatism curve of the optical system of the fourth embodiment of the present invention;

[0033] Figure 11 shows a magnification chromatic aberration curve of the optical system of Example 4 of the present invention;

[0034] Figure 12 FIG2 shows a schematic structural diagram of an optical system according to a fifth embodiment of the present invention;

[0035] Figure 13 FIG2 shows a schematic structural diagram of an optical system according to a sixth embodiment of the present invention;

[0036] Figure 14 FIG2 shows a schematic structural diagram of an optical system according to a seventh embodiment of the present invention;

[0037] Figure 15 shows an axial chromatic aberration curve of the optical system of Example 7 of the present invention;

[0038] Figure 16 FIG4 shows an astigmatism curve of the optical system of the seventh embodiment of the present invention;

[0039] Figure 17 shows a magnification chromatic aberration curve of the optical system of Example 7 of the present invention;

[0040] Figure 18 FIG2 shows a schematic structural diagram of an optical system according to an eighth embodiment of the present invention;

[0041] Figure 19 FIG2 shows a schematic structural diagram of an optical system according to a ninth embodiment of the present invention;

[0042] Figure 20 The figure shows a defocus transfer function curve of an optical system of an optional solution 1 of the present invention under the conditions of T45 / T34=5.4 and CT4 / EP34=1.85;

[0043] Figure 21 The defocus transfer function curve of the optical system of Comparative Example 1 under the conditions of T45 / T34=5.4 and CT4 / EP34=1.22 is shown;

[0044] Figure 22 The defocus transfer function curve of the optical system of Comparative Example 2 under the conditions of T45 / T34=5.4 and CT4 / EP34=2.41 is shown.

[0045] The above drawings include the following reference numerals:

[0046] P0, lens barrel; E1, first lens; S1, object-side surface of first lens; S2, image-side surface of first lens; P1, first spacer; E2, second lens; S3, object-side surface of second lens; S4, image-side surface of second lens; P2, second spacer;

[0047] E3, third lens; S5, object-side surface of the third lens; S6, image-side surface of the third lens; P3, third spacer; E4, fourth lens; S7, object-side surface of the fourth lens; S8, image-side surface of the fourth lens; P4, fourth spacer; E5, fifth lens; S9, object-side surface of the fifth lens; S10, image-side surface of the fifth lens; P5, fifth spacer. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] 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 ordinary technicians in the technical field to which this application belongs.

[0050] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0051] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of this application.

[0052] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0053] In this article, the paraxial area refers to the area near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial area; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial area. The judgment of the surface shape in the paraxial area can be based on the judgment method of ordinary knowledge in this field, and the positive and negative R value (R refers to the curvature radius of the paraxial area, usually refers to the R value on the lens database (lens data) in the optical software) is used to judge the convexity and concavity. For the object side surface, when the R value is positive, it is judged as a convex surface, and when the R value is negative, it is judged as a concave surface; for the image side surface, when the R value is positive, it is judged as a concave surface, and when the R value is negative, it is judged as a convex surface.

[0054] In this article, effective light refers to light that can be accurately focused on the imaging surface directly or after being refracted within the optical system. These light rays follow the laws of optics, such as refraction and reflection, when passing through the optical system, ultimately forming a clear image on the imaging surface.

[0055] In this article, invalid light refers to light that does not participate in the imaging process. This includes light that enters the optical system but does not focus on the imaging surface, or light that is scattered, reflected, or absorbed within the optical system. Invalid light can be caused by physical limitations of the optical system design (such as asymmetric or imperfect lens shapes), or by factors such as uneven surfaces, dust, scratches, or uneven coatings on optical components. Invalid light not only fails to improve image quality, but may also cause image blur, reduce contrast, or produce undesirable effects such as light spots and glare.

[0056] In this article, each lens is composed of an integrally formed effective diameter portion and a mechanical portion. The mechanical portion is annular and connected to the outer peripheral side of the effective diameter portion. The effective diameter portion is used for light to pass through and participate in imaging; while the mechanical portion is not used for light to pass through and does not participate in imaging, but is used to contact adjacent spacers, adjacent lenses or lens barrels.

[0057] In order to solve the problem of divergence of the defocus curve of the optical system in the prior art, the present invention provides an optical system.

[0058] First embodiment

[0059] like Figures 1 to 20As shown, the optical system includes a lens group, a plurality of spacers and a lens barrel, the lens group includes five lenses with optical power, and the lens group includes a first lens to a fifth lens in sequence from the object side to the image side of the optical system; among the plurality of spacers, the third spacer is located between the third lens and the fourth lens and is in at least partial contact with the image side surface of the third lens, and the fourth spacer is located between the fourth lens and the fifth lens and is in at least partial contact with the image side surface of the fourth lens; the lens barrel has a receiving space, and the lens group and the plurality of spacers are accommodated in the receiving space; wherein, the air gap T34 between the third lens and the fourth lens on the optical axis of the optical system and the air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy the following: 4.9≤T45 / T34≤6.99; the center thickness CT4 of the fourth lens on the optical axis and the spacing distance EP34 between the third spacer and the fourth spacer along the optical axis satisfy the following: 1.47≤CT4 / EP34≤2.03.

[0060] To balance the Petzval field curvature of the optical system, the surface curvature of the fourth and fifth lenses of the five-element optical system of this application is relatively large. This results in the air spacing between the fourth and fifth lenses on the optical axis being larger than the air spacing between the fourth and third lenses on the optical axis, and satisfies the condition 4.9≤T45 / T34≤6.99, making the fourth lens more sensitive during assembly. By controlling the ratio of the center thickness of the fourth lens on the optical axis to the spacing distance between the third and fourth spacers, this application indirectly controls the shape and thickness of the effective diameter and mechanical parts of the fourth lens, thereby limiting the refraction angle of light when passing through the third and fourth lenses, improving the concentration of the optical system's defocus curve, and simultaneously avoiding the shape of the fourth lens being at an extreme design limit, improving the processability of the fourth lens, reducing assembly sensitivity, and achieving a better defocus transfer function performance for the optical system.

[0061] Table 1 below and Figures 20 to 22 Defocus modulation transfer function curves of the optical systems of Comparative Example 1, Comparative Example 2 and an optional solution 1 of the present application are given when T45 / T34=5.4 and CT4 / EP34 take different values, describing the image transmission capability of the optical system at different spatial frequencies. The X-axis is the defocus position (unit: mm), indicating the position where the imaging deviates from the optimal focus (X=0 mm), and the Y-axis represents the defocus modulation transfer function value, thereby intuitively comparing the changes in the imaging quality of the optical system.

[0062] Table 1

[0063] Comparative Example 1 This application plan 1 Comparative Example 2 T45 / T34 5.4 5.4 5.4 CT4 / EP34 1.22 1.85 2.41 Optical system judgment Unqualified qualified Unqualified

[0064] From Table 1 and Figure 21It can be seen that under the condition of CT4 / EP34=1.22, the optical system of Comparative Example 1 has a large chromatic aberration and a serious divergence of the defocus curve, and the optical system is judged to be unqualified. Figure 22 It can be seen that the optical system of Comparative Example 2 is more sensitive to image plane deviation under the condition of CT4 / EP34=2.41, the defocus curve drops rapidly, and the optical system is judged to be unqualified. Figure 20 As shown, under the condition of CT4 / EP34=1.85, that is, satisfying the condition of 1.47≤CT4 / EP34≤2.03, the defocus curves of each field of view are relatively concentrated, the imaging performance of the optical system is good, and it is judged to be qualified.

[0065] In this embodiment, among the multiple spacers, the first spacer is located between the first lens and the second lens and at least partially contacts the image-side surface of the first lens. The curvature radius R1 of the object-side surface of the first lens, the inner diameter d0s of the object-side end surface of the lens barrel, and the inner diameter d1s of the object-side surface of the first spacer satisfy the following relationship: 2.83≤R1 / (d0s-d1s)≤3.78. By limiting R1 / (d0s-d1s) within a reasonable range and controlling the ratio of the curvature radius of the object-side surface of the first objective lens to the difference between the inner diameter of the object-side end surface of the lens barrel and the inner diameter of the object-side surface of the first spacer, the shape of the inner diameter chamfer of the first spacer is controlled, thereby preventing stray light from being transmitted from the object-side surface of the first lens to the inner diameter surface of the first spacer, thereby improving the imaging quality of the optical system.

[0066] In this embodiment, among the multiple spacers, the first spacer is located between the first lens and the second lens and at least partially contacts the image-side surface of the first lens. The effective focal length f1 of the first lens, the spacing distance EP01 from the object-side end face of the lens barrel to the object-side surface of the first spacer along the optical axis, and the center thickness CT1 of the first lens on the optical axis satisfy the following conditions: -4.87 ≤ f1 / (EP01 + CT1) ≤ -2.93. By limiting f1 / (EP01 + CT1) within a reasonable range and controlling the ratio of the effective focal length of the first lens to the sum of the spacing distance from the object-side end face of the lens barrel to the first spacer and the center thickness of the first lens, the focal length and shape of the first lens at the front end of the optical system are controlled, thereby achieving a smooth transition of light rays reaching the second lens, reducing the angle of incidence of light rays on subsequent elements, and improving MTF (Modulation Transfer Function) performance.

[0067] In this embodiment, among the multiple spacers, the first spacer is located between the first lens and the second lens and is in at least partial contact with the image side surface of the first lens. The curvature radius R2 of the image side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer, and the inner diameter d1s of the object side surface of the first spacer satisfy the following relationship: 0.67≤R2 / (D1s-d1s)≤1.39. By limiting R2 / (D1s-d1s) within a reasonable range and controlling the ratio of the curvature radius of the image side surface of the first lens to the difference between the outer diameter and the inner diameter of the object side surface of the first spacer, the purpose of controlling the thickness of the supporting members of the front and rear lenses supported by the first spacer is achieved, thereby preventing the supporting members of the lenses from being too thin, reducing the risk of unstable supporting member thickness caused by mold shrinkage of the first spacer, and also reducing the risk of unstable assembly of the second lens caused by deformation of the first spacer during assembly of the second lens.

[0068] In this embodiment, among the multiple spacers, the first spacer is located between the first and second lenses and at least partially in contact with the image-side surface of the first lens, and the second spacer is located between the second and third lenses and at least partially in contact with the image-side surface of the second lens. The effective focal length f2 of the second lens, the air spacing T12 between the first and second lenses on the optical axis, and the separation distance EP12 between the first and second spacers along the optical axis satisfy the following relationship: 1.29 ≤ f2 / (T12 + EP12) ≤ 2.83. By limiting f2 / (T12 + EP12) to a reasonable range and controlling the ratio of the effective focal length of the second lens to the sum of the air spacing T12 between the first and second lenses on the optical axis and the separation distances between the first and second spacers, the thickness of the structural components of the first and second lenses can be controlled. Because the image-side surface of the first lens and the object-side surface of the second lens are relatively close at the edge of the effective diameter, increasing the thickness of the structural components of the lens while ensuring uniform thickness of the individual components can prevent interference between the first and second lenses due to assembly deformation, thereby reducing the sensitivity of the optical system.

[0069] In this embodiment, the second spacer, located between the second and third lenses and at least partially in contact with the image-side surface of the second lens, satisfies the following conditions: the radius of curvature R3 of the object-side surface of the second lens, the center thickness CT2 of the second lens on the optical axis, and the inner diameter d2s of the object-side surface of the second spacer. By limiting R3 × CT2 / d2s to a reasonable range and controlling the ratio of the product of the radius of curvature of the object-side surface of the second lens and the center thickness CT2 of the second lens on the optical axis to the inner diameter of the object-side surface of the second spacer, the passage of ineffective light can be effectively blocked, while meeting design requirements and improving the RI at the edge of the field of view, thereby enhancing the overall imaging quality of the optical system.

[0070] In this embodiment, the second spacer, located between the second and third lenses and at least partially in contact with the image-side surface of the second lens, satisfies the following relationship: -2.07 ≤ R4 / D2s ≤ -0.37. By limiting R4 / D2s to a reasonable range and controlling the ratio of the outer diameter of the object-side surface of the second spacer to the radius of curvature of the image-side surface of the second lens, the marginal light pattern of the second lens and the shape of the second lens can be controlled. This, in turn, prevents stray light while maintaining optical parameters, thereby ensuring image quality.

[0071] In this embodiment, the second spacer, located between the second and third lenses and at least partially in contact with the image-side surface of the second lens, satisfies the following conditions: 6.01 ≤ CT2 / (T23 + CP2) ≤ 6.29. By limiting CT2 / (T23 + CP2) to a reasonable range and controlling the ratio of the second lens's center thickness on the optical axis to the sum of the air spacing between the second and third lenses and the maximum thickness of the second spacer, the sensitivity of the second and third lenses to assembly tilt is reduced, thereby improving the stability of the assembly performance of the second and third lenses.

[0072] In this embodiment, among the multiple spacers, the second spacer is located between the second lens and the third lens and at least partially contacts the image side surface of the second lens. The radius of curvature R5 of the object side surface of the third lens, the outer diameter D2m of the image side surface of the second spacer, and the inner diameter d2m of the image side surface of the second spacer satisfy the following relationship: 0.77≤R5 / (D2m-d2m)≤3.48. By limiting R5 / (D2m-d2m) to a reasonable range and controlling the ratio of the radius of curvature of the object side surface of the third lens to the difference between the outer diameter and the inner diameter of the image side surface of the second spacer, the cantilever length of the second spacer is controlled, thereby preventing the cantilever of the second spacer from being excessively long and causing deformation of the second spacer due to baking, thereby reducing the risk of aperture position offset in the optical system and ensuring the optical path.

[0073] In this embodiment, the second spacer, located between the second and third lenses and at least partially in contact with the image-side surface of the second lens, satisfies the following relationship: 1.72 ≤ EP23 / CT3 ≤ 2.06. By limiting EP23 / CT3 to a reasonable range and controlling the ratio of the spacing between the second and third lenses and the center thickness of the third lens on the optical axis, the divergence angle of light rays from the front lens assembly is controlled. This also ensures a smooth transition in the overall shape of the second lens, avoiding excessive fluctuations in the thickness ratio and enhancing the molding stability of the second lens.

[0074] In this embodiment, the outer diameter D3s of the object-side surface of the third spacer, the inner diameter d3s of the object-side surface of the third spacer, and the radius of curvature R6 of the image-side surface of the third lens satisfy the following relationship: 1.09 ≤ (D3s - d3s) / R6 ≤ 1.50. By limiting (D3s - d3s) / R6 to a reasonable range and controlling the ratio of the difference between the outer and inner diameters of the object-side surface of the third spacer and the radius of curvature of the image-side surface of the third lens, the range of marginal rays on the image side of the third lens can be controlled, thereby preventing the risk of excessive divergence of marginal rays on the image side of the third lens, resulting in a high risk of light leakage, and thus reducing the risk of stray light passing through the image side of the third lens.

[0075] In this embodiment, the outer diameter D3m of the image-side surface of the third spacer and the radius of curvature R7 of the object-side surface of the fourth lens satisfy the following relationship: 0.95 ≤ D3m / R7 ≤ 2.69. By limiting D3m / R7 to a reasonable range and controlling the ratio of the outer diameter of the image-side surface of the third spacer to the radius of curvature of the object-side surface of the fourth lens, the risk of internal stray light from the third lens entering the fourth lens through the engagement position, when the third and fourth lenses are partially engaged, can be reduced, thereby ensuring image cleanliness.

[0076] In this embodiment, the outer diameter D4s of the object-side surface of the fourth spacer and the radius of curvature R8 of the image-side surface of the fourth lens satisfy the following relationship: -2.83 ≤ D4s / R8 ≤ -2.39. By limiting D4s / R8 to a reasonable range and controlling the ratio of the outer diameter of the object-side surface of the fourth spacer to the radius of curvature of the image-side surface of the fourth lens, the range of marginal light on the image side of the fourth lens can be controlled. Simultaneously, the fourth spacer can block internally reflected stray light from the fourth lens, reducing stray light energy on the imaging surface.

[0077] In this embodiment, the outer diameter D4m of the image-side surface of the fourth spacer, the inner diameter d4m of the image-side surface of the fourth spacer, and the radius of curvature R9 of the object-side surface of the fifth lens satisfy the following relationship: -1.83 ≤ (D4m - d4m) / R9 ≤ -1.41. By limiting (D4m - d4m) / R9 to a reasonable range and controlling the ratio of the difference between the outer and inner diameters of the image-side surface of the fourth spacer to the radius of curvature of the object-side surface of the fifth lens, the cantilever length of the fourth spacer can be controlled, preventing the cantilever from being too long and causing deformation of the fourth spacer during baking, thereby reducing the risk of aperture position shift in the optical system.

[0078] Second embodiment

[0079] like Figures 1 to 20 As shown, the optical system includes a lens group, a plurality of spacers and a lens barrel, the lens group includes five lenses with optical power, and the lens group includes a first lens to a fifth lens in sequence from the object side to the image side of the optical system; among the plurality of spacers, the third spacer is located between the third lens and the fourth lens and is in at least partial contact with the image side surface of the third lens, and the fourth spacer is located between the fourth lens and the fifth lens and is in at least partial contact with the image side surface of the fourth lens; the lens barrel has a receiving space, and the lens group and the plurality of spacers are accommodated in the receiving space; wherein, the air gap T34 between the third lens and the fourth lens on the optical axis of the optical system and the air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy the following: 4.9≤T45 / T34≤6.99; the outer diameter D4s of the object side surface of the fourth spacer and the curvature radius R8 of the image side surface of the fourth lens satisfy the following: -2.83≤D4s / R8≤-2.39.

[0080] To balance the Petzval field curvature of the optical system, the five-element optical system of this application features a significant curvature of the fifth lens surface. This results in a large edge-to-thickness ratio, satisfying the requirement of 4.9≤T45 / T34≤6.99. This increases the risk of marginal light rays entering the structural components of the fifth lens, generating significant internal reflection stray light and affecting image cleanliness. By controlling the ratio of the outer diameter of the object-side surface of the fourth spacer to the radius of curvature of the image-side surface of the fourth lens, this application can control the range of marginal light rays on the image side of the fourth lens, preventing them from entering the structural components of the fifth lens and generating stray light. This also enables the fourth spacer to block internal reflection stray light from the fourth lens, reducing the amount of stray light on the imaging surface.

[0081] It should be noted that, in this embodiment, other conditional expressions in the above embodiment may also be included, which will not be described one by one here.

[0082] Optionally, the optical system may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0083] The optical system in the present application may utilize multiple lenses, such as the seven lenses described above. In the present application, at least one of the lens surfaces is an aspheric surface. Aspheric lenses are characterized by a continuously varying curvature from the center of the lens to the periphery. Unlike spherical lenses, which have a constant curvature from the center to the periphery, aspheric lenses have a better curvature radius characteristic, with the advantages of improved distortion aberration and improved astigmatism. By utilizing aspheric lenses, aberrations that occur during imaging can be eliminated as much as possible, thereby improving imaging quality.

[0084] However, those skilled in the art will appreciate that the number of lenses comprising the optical system can be varied to achieve the various results and advantages described herein without departing from the claimed technical solutions. For example, while the embodiments describe an optical system using seven lenses as an example, the optical system is not limited to including seven lenses. If desired, the optical system may also include other numbers of lenses.

[0085] Figure 1 A schematic diagram of the dimensions of an optical system of the present application is shown. Figure 1 Parameters such as D1s, d4m, and EP23 are marked in the figure to provide a clear and intuitive understanding of their significance. To facilitate the description of the optical system and the specific lens surface, these parameters will not be reflected in the accompanying drawings when describing specific embodiments.

[0086] It should be noted that in an optical system, the surface of the object-side end of the lens barrel closest to the object side is the object-side end face of the lens barrel, and the surface of the image-side end of the lens barrel closest to the image side is the image-side end face of the lens barrel.

[0087] Optionally, the optical system in the embodiments of the present application can be simulated using software and / or tools such as ZEMAX and CODEV. Optionally, the optical system can be simulated using CODEV software. During the simulation using the above-mentioned software and / or tools, the surface shape of each lens can be appropriately adjusted based on the surface shape of the software and / or tool used.

[0088] In this embodiment, each lens can be configured as a trimmed lens. The outer diameter surface of the trimmed lens has a trimmed structure and a non-trimmed structure, and the outer diameter of the trimmed structure is smaller than the outer diameter of the non-trimmed structure. The outer diameter of the trimmed lens generally refers to the outer diameter of the non-trimmed structure.

[0089] In this embodiment, each spacer can be configured as a trimming spacer. The outer annular surface of the trimming spacer has a trimming portion and a non-trimming portion, and the outer diameter of the trimming portion is smaller than the outer diameter of the non-trimming portion. The outer diameter of the trimming spacer generally refers to the maximum outer diameter of the non-trimming portion.

[0090] The following further describes examples of specific surface shapes and parameters of the optical system applicable to the above-mentioned embodiment with reference to the accompanying drawings.

[0091] It should be noted that any one of the following embodiments 1 to 9 is applicable to all implementation methods of the present application.

[0092] Example 1

[0093] like Figure 2 As shown, the optical system of embodiment 1 of the present application is described. Figure 2 A schematic structural diagram of the optical system of embodiment 1 is shown.

[0094] like Figure 2 As shown, the optical system includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, and a fifth spacer P5.

[0095] In this embodiment, the first lens E1 has negative focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The second lens E2 has positive focal power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The third lens E3 has negative focal power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative focal power, the object-side surface S9 of the fifth lens is concave, and the image-side surface S10 of the fifth lens is concave. The optical system also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). Light from the object surface passes through S1 to S14 to reach the imaging surface S15 (not shown in the figure).

[0096] Table 2 shows the basic structural parameters of the optical system of Example 1, where the units of curvature radius, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) is the object plane, and the aperture is located between the first lens and the second lens.

[0097] Table 2

[0098]

[0099]

[0100] In the first embodiment, each lens is an aspheric lens, and the aspheric surface shape can be defined by, but not limited to, the following aspheric surface formula:

[0101]

[0102] Where x is the distance vector from the vertex of the aspheric surface at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c = 1 / R, i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 2 above; k is the conic coefficient; and Ai is the correction coefficient for the i-th order of the aspheric surface. Table 3 below lists the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A24, A26, A28, and A30 that can be used for each aspheric mirror surface S1-S10 in Example 1.

[0103] Table 3

[0104]

[0105]

[0106] Figure 3 The axial chromatic aberration curve of the optical system of the first embodiment is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical system. Figure 4 The astigmatism curve of the optical system of Example 1 is shown, which represents the meridional field curvature and the sagittal field curvature. Figure 5 The chromatic aberration of magnification curve of the optical system of Example 1 is shown, which indicates the degree to which the focusing points of light rays of different wavelengths do not completely overlap.

[0107] according to Figures 3 to 5 It can be seen that the optical system provided in the first embodiment can achieve good imaging quality.

[0108] Example 2

[0109] like Figure 6 , which describes the optical system of Example 2 of the present application. The optical system of this embodiment has the same optical parameters as Example 1, the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description in Example 1 and will not repeat them here.

[0110] Example 3

[0111] like Figure 7 , which describes the optical system of Example 3 of the present application. The optical system of this embodiment has the same optical parameters as that of Example 1, and the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description in Example 1 and will not repeat them here.

[0112] Example 4

[0113] like Figure 8 As shown, the optical system of embodiment 4 of the present application is described. Figure 8A schematic structural diagram of an optical system of embodiment 4 is shown.

[0114] like Figure 8 As shown, the optical system includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, and a fifth spacer P5.

[0115] In this embodiment, the first lens E1 has negative focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The second lens E2 has positive focal power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The third lens E3 has negative focal power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative focal power, the object-side surface S9 of the fifth lens is concave, and the image-side surface S10 of the fifth lens is concave. The optical system also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). Light from the object surface passes through S1 to S14 to reach the imaging surface S15 (not shown in the figure).

[0116] Table 4 shows the basic structural parameters of the optical system of Example 4, where the units of curvature radius, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) is the object plane, and the aperture is located between the first lens and the second lens.

[0117] Table 4

[0118] Face number Surface type Radius of curvature Thickness / distance Refractive index Abbe number Cone coefficient OBJ spherical surface endless endless S1 Aspheric 10.0000 0.3800 1.63 23.3 0.0000 S2 Aspheric 2.7505 0.4747 0.0000 STO spherical surface endless 0.0800 S3 Aspheric 4.4652 0.7119 1.54 55.9 0.0000 S4 Aspheric -2.6501 0.0950 0.0000 S5 Aspheric 1.9732 0.3300 1.67 19.2 0.0000 S6 Aspheric 1.7930 0.0800 0.0000 S7 Aspheric 1.8464 1.0000 1.54 55.9 0.0000 S8 Aspheric -1.9444 0.4374 0.0000 S9 Aspheric -1.3990 0.4500 1.67 19.2 -8.4711 S10 Aspheric 3.1419 0.0910 -2.5487 S13 spherical surface endless 0.1700 1.52 64.2 S14 spherical surface endless 0.4000 S15 spherical surface endless

[0119] In Example 4, each lens is an aspheric lens, and the aspheric surface shape can be defined using, but not limited to, formula (1) in Example 1. Table 5 below lists the high-order coefficients of each aspheric lens surface S1-S10 that can be used in Example 4.

[0120] Table 5

[0121] Face number A4 A6 A8 A10 A12 A14 A16 S1 1.8074E-01 -1.0485E-02 -9.5390E-04 -8.8409E-04 -4.2990E-05 -7.5915E-05 -7.8788E-05 S2 1.7108E-01 2.5358E-02 9.6828E-03 2.5016E-03 9.8938E-04 8.7591E-05 7.5104E-05 S3 3.5883E-03 -2.5394E-04 1.3301E-04 4.7864E-05 -2.7442E-05 -4.3655E-06 -1.0749E-05 S4 -1.5532E-01 1.4340E-02 -2.3398E-03 1.4162E-03 -1.3397E-04 2.0154E-04 8.2260E-05 S5 -1.5636E-01 1.0387E-02 -5.0106E-03 1.3210E-03 -4.4042E-04 1.0903E-04 -4.5759E-05 S6 -3.3842E-01 1.4014E-02 -1.5612E-02 1.2223E-03 -2.8600E-03 1.2588E-04 -7.1003E-05 S7 -2.9136E-01 3.0879E-02 -4.4997E-03 3.7685E-03 -1.2494E-03 -1.5704E-04 -1.3763E-04 S8 -1.2990E-01 7.2416E-03 1.5770E-02 4.2618E-03 3.1975E-03 1.0148E-03 5.3038E-04 S9 -7.4183E-01 1.8137E-01 -8.8529E-03 2.4921E-03 3.0597E-03 2.0829E-03 -9.3528E-04 S10 -9.5009E-01 2.4797E-01 -5.5276E-02 -1.8614E-03 -5.9185E-03 4.5753E-04 -3.5729E-03 Face number A18 A20 A22 A24 A26 A28 A30 S1 -5.9255E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S2 -3.8988E-05 7.8693E-05 3.0023E-05 4.9690E-05 0.0000E+00 0.0000E+00 0.0000E+00 S3 2.0372E-05 1.4696E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 2.7228E-05 2.9123E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 1.8610E-05 -3.3552E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 4.5051E-05 -5.8242E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 6.6509E-05 -1.0361E-05 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 1.3212E-05 6.0759E-06 -9.0658E-05 -2.2979E-05 -5.2100E-05 -2.2831E-06 0.0000E+00 S9 -5.7234E-05 -2.2079E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 -7.2561E-04 -6.9187E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0122] Figure 9 The axial chromatic aberration curve of the optical system of Example 4 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical system. Figure 10 The astigmatism curve of the optical system of Example 4 is shown, which represents the meridional field curvature and the sagittal field curvature. Figure 11The chromatic aberration of magnification curve of the optical system of Example 4 is shown, which indicates the degree to which the focusing points of light rays of different wavelengths do not completely overlap.

[0123] according to Figures 9 to 11 It can be seen that the optical system provided in the fourth embodiment can achieve good imaging quality.

[0124] Example 5

[0125] like Figure 12 , which describes the optical system of Example 5 of the present application. The optical system of this embodiment has the same optical parameters as Example 4, the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description of Example 4 and will not be repeated here.

[0126] Example 6

[0127] like Figure 13 , which describes the optical system of Example 6 of the present application. The optical system of this embodiment has the same optical parameters as that of Example 4, and the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description in Example 4, and will not be repeated here.

[0128] Example 7

[0129] like Figure 14 As shown, the optical system of embodiment 7 of the present application is described. Figure 14 A schematic structural diagram of the optical system of Example 7 is shown.

[0130] like Figure 14 As shown, the optical system includes, from the object side to the image side, the following housed in the lens barrel P0: a first lens E1, a first spacer P1, a second lens E2, a second spacer P2, a third lens E3, a third spacer P3, a fourth lens E4, a fourth spacer P4, a fifth lens E5, and a fifth spacer P5.

[0131] In this embodiment, the first lens E1 has negative focal power, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The second lens E2 has positive focal power, the object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is convex. The third lens E3 has negative focal power, the object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is concave. The fourth lens E4 has positive focal power, the object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The fifth lens E5 has negative focal power, the object-side surface S9 of the fifth lens is concave, and the image-side surface S10 of the fifth lens is concave. The optical system also includes a filter or protective glass (not shown in the figure), which has an object-side surface S13 (not shown in the figure) and an image-side surface S14 (not shown in the figure). Light from the object surface passes through S1 to S14 to reach the imaging surface S15 (not shown in the figure).

[0132] Table 6 shows the basic structural parameters of the optical system of Example 7, where the units of curvature radius, thickness / distance, effective radius, and focal length are all in millimeters (mm). OBJ (not shown) is the object plane, and the aperture is located between the first lens and the second lens.

[0133] Table 6

[0134]

[0135]

[0136] In Example 7, each lens is an aspheric lens, and the aspheric surface shape can be defined using, but not limited to, formula (1) in Example 1. Table 7 below lists the high-order coefficients of each aspheric lens surface S1-S10 that can be used in Example 7.

[0137] Table 7

[0138]

[0139] Figure 15 The axial chromatic aberration curve of the optical system of Example 7 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical system. Figure 16 The astigmatism curve of the optical system of Example 7 is shown, which represents the meridional field curvature and the sagittal field curvature. Figure 17 The chromatic aberration of magnification curve of the optical system of Example 7 is shown, which indicates the degree to which the focusing points of light rays of different wavelengths do not completely overlap.

[0140] according to Figures 15 to 17 It can be seen that the optical system provided in Example 7 can achieve good imaging quality.

[0141] Example 8

[0142] like Figure 18 , which describes the optical system of Example 8 of the present application. The optical system of this embodiment has the same optical parameters as that of Example 7, and the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description of Example 7, and will not be repeated here.

[0143] Example 9

[0144] like Figure 19 , which describes the optical system of Example 9 of the present application. The optical system of this embodiment has the same optical parameters as Example 7, and the same arrangement of lenses and spacers, but different structural parameters. Please refer to the relevant description in Example 7, and will not be repeated here.

[0145] In summary, the first to ninth embodiments of the optical system respectively satisfy the relationships shown in Table 8.

[0146] Table 8

[0147] Conditional formula / Example one two three Four five six seven eight Nine R1 / (d0s-d1s) 2.87 2.83 2.87 3.78 3.60 3.64 3.45 3.30 3.42 f1 / (EP01+CT1) -4.83 -4.87 -4.79 -4.25 -4.31 -4.45 -2.93 -2.97 -3.06 R2 / (D1s-d1s) 0.86 0.86 1.27 1.02 0.98 1.39 0.70 0.67 1.15 f2 / (T12+EP12) 2.79 2.81 2.83 2.75 2.73 2.75 1.29 1.29 1.29 R3×CT2 / d2s 0.99 1.00 1.00 1.69 1.69 1.72 1.15 1.16 1.16 R4 / D2s -1.66 -1.68 -2.07 -0.61 -0.60 -0.78 -0.38 -0.37 -0.51 CT2 / (T23+CP2) 6.29 6.29 6.29 6.08 6.08 6.08 6.01 6.01 6.01 R5 / (D2m-d2m) 0.77 0.78 1.17 0.80 0.77 1.26 1.92 1.84 3.48 EP23 / CT3 2.02 1.99 2.06 1.82 1.82 1.95 1.72 1.72 1.87 (D3s-d3s) / R6 1.47 1.50 1.47 1.31 1.37 1.34 1.09 1.13 1.09 CT4 / EP34 1.83 1.67 1.79 2.03 1.95 1.92 1.60 1.47 1.53 T45 / T34 6.99 6.99 6.99 5.47 5.47 5.47 4.90 4.90 4.90 D3m / R7 2.67 2.69 2.68 2.49 2.55 2.51 0.95 0.97 0.95 D4s / R8 -2.81 -2.83 -2.82 -2.53 -2.59 -2.56 -2.39 -2.44 -2.39 (D4m-d4m) / R9 -1.70 -1.74 -1.71 -1.77 -1.83 -1.80 -1.41 -1.46 -1.41

[0148] Table 9 lists the optical parameters of the optical systems of Examples 1 to 9. Wherein, TTL is the total length of the optical system, specifically the distance from the object-side surface of the first lens to the imaging plane of the optical system on the optical axis; ImgH is the image height of the optical system, specifically half the diagonal length of the effective pixel area on the imaging plane of the optical system, 2.24 mm ≤ ImgH ≤ 2.30 mm; Semi-FOV is half the maximum field of view of the optical system, 63.00° ≤ Semi-FOV ≤ 65.00°; Fno is the F-number of the optical system; and f is the focal length of the entire optical system.

[0149] Table 9

[0150]

[0151]

[0152] Table 10 lists the parameters of the spacers of the optical systems of Examples 1 to 9, in units of mm.

[0153] Table 10

[0154] Parameters / Example one two three Four five six seven eight Nine d1s 1.534 1.494 1.550 1.423 1.389 1.303 1.399 1.365 1.368 D1s 4.420 4.380 3.513 4.110 4.210 3.284 4.240 4.340 3.087 d2s 1.914 1.908 1.908 1.882 1.885 1.852 1.895 1.889 1.884 d2m 1.914 1.908 1.908 1.882 1.885 1.852 1.895 1.889 1.884 D2s 4.620 4.580 3.703 4.344 4.444 3.414 4.460 4.560 3.297 D2m 4.620 4.580 3.703 4.344 4.444 3.414 4.460 4.560 3.297 d3s 2.100 2.086 2.106 2.248 2.246 2.244 2.114 2.103 2.114 D3s 4.750 4.790 4.770 4.600 4.700 4.640 4.680 4.780 4.680 D3m 4.750 4.790 4.770 4.600 4.700 4.640 4.680 4.780 4.680 d4m 2.550 2.540 2.554 2.447 2.463 2.449 2.202 2.212 2.202 D4s 4.920 4.960 4.940 4.928 5.028 4.968 4.860 4.960 4.860 D4m 4.920 4.960 4.940 4.928 5.028 4.968 4.860 4.960 4.860 d0s 4.322 4.322 4.342 4.069 4.169 4.050 4.294 4.394 4.294 EP01 1.052 1.042 1.062 1.065 1.045 0.999 1.228 1.208 1.165 EP12 0.596 0.586 0.576 0.596 0.606 0.597 0.734 0.734 0.733 EP23 0.566 0.556 0.576 0.599 0.599 0.643 0.638 0.638 0.692 EP34 0.508 0.558 0.518 0.492 0.512 0.522 0.456 0.496 0.476 CP2 0.022 0.022 0.022 0.022 0.022 0.022 0.022 0.022 0.022

[0155] The present application also provides an imaging device, wherein the electronic photosensitive element thereof may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device may be a standalone 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.

[0156] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0157] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0158] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0159] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An optical system, characterized in that: include: a lens group, wherein the number of lenses having optical power in the lens group is five, and the lens group includes, from the object side to the image side of the optical system, a first lens to a fifth lens; a plurality of spacers, wherein a third spacer is located between the third lens and the fourth lens and at least partially contacts the image-side surface of the third lens, and a fourth spacer is located between the fourth lens and the fifth lens and at least partially contacts the image-side surface of the fourth lens; a lens barrel having a receiving space, wherein the lens group and the plurality of spacers are accommodated in the receiving space; The air interval T34 between the third lens and the fourth lens on the optical axis of the optical system and the air interval T45 between the fourth lens and the fifth lens on the optical axis satisfy the following: 4.9≤T45 / T34≤6.99; A center thickness CT4 of the fourth lens on the optical axis and a spacing distance EP34 between the third spacer and the fourth spacer along the optical axis satisfy the following: 1.47≤CT4 / EP34≤2.

03.

2. The optical system according to claim 1, wherein: Among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens. The curvature radius R1 of the object side surface of the first lens, the inner diameter d0s of the object side end surface of the lens barrel, and the inner diameter d1s of the object side surface of the first spacer satisfy the following: 2.83≤R1 / (d0s-d1s)≤3.

78.

3. The optical system according to claim 1, wherein: Among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens. The curvature radius R2 of the image side surface of the first lens, the outer diameter D1s of the object side surface of the first spacer, and the inner diameter d1s of the object side surface of the first spacer satisfy the following: 0.67≤R2 / (D1s-d1s)≤1.

39.

4. The optical system according to claim 1, wherein: Among the multiple spacers, the first spacer is located between the first lens and the second lens and is at least partially in contact with the image side surface of the first lens. The effective focal length f1 of the first lens, the spacing distance EP01 from the object side end surface of the lens barrel to the object side surface of the first spacer along the direction of the optical axis, and the center thickness CT1 of the first lens on the optical axis satisfy the following: -4.87≤f1 / (EP01+CT1)≤-2.

93.

5. The optical system according to claim 1, wherein: Among the multiple spacers, the first spacer is located between the first lens and the second lens and is in at least partial contact with the image side surface of the first lens, and the second spacer is located between the second lens and the third lens and is in at least partial contact with the image side surface of the second lens. The effective focal length f2 of the second lens, the air gap T12 between the first lens and the second lens on the optical axis, and the spacing distance EP12 between the first spacer and the second spacer along the direction of the optical axis satisfy the following: 1.29≤f2 / (T12+EP12)≤2.

83.

6. The optical system according to claim 1, wherein: Among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens. The curvature radius R3 of the object side surface of the second lens, the center thickness CT2 of the second lens on the optical axis, and the inner diameter d2s of the object side surface of the second spacer satisfy the following: 0.99mm≤R3×CT2 / d2s≤1.72mm.

7. The optical system according to claim 1, wherein: Among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens, and the curvature radius R4 of the image side surface of the second lens and the outer diameter D2s of the object side surface of the second spacer satisfy the following: -2.07≤R4 / D2s≤-0.

37.

8. The optical system according to claim 1, wherein: Among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens, and the center thickness CT2 of the second lens on the optical axis, 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 satisfy the following: 6.01≤CT2 / (T23+CP2)≤6.

29.

9. The optical system according to claim 1, wherein: Among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens. The curvature radius R5 of the object side surface of the third lens and the outer diameter D2m of the image side surface of the second spacer and the inner diameter d2m of the image side surface of the second spacer satisfy the following relationship: 0.77≤R5 / (D2m-d2m)≤3.

48.

10. The optical system according to claim 1, wherein: Among the multiple spacers, the second spacer is located between the second lens and the third lens and is at least partially in contact with the image side surface of the second lens. The spacing distance EP23 between the second spacer and the third spacer along the direction of the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy the following: 1.72≤EP23 / CT3≤2.06.

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