Optical imaging system

Abstract

The application provides an optical imaging system. The optical imaging system comprises a lens barrel, a lens set arranged in the lens barrel and a plurality of isolation pieces, the lens set is composed of five lenses, the five lenses are sequentially a first lens, a second lens, a third lens, a fourth lens and a fifth lens from an object side to an image side; 154.46°<=FOV<=180.03° is met; and 12.80<=d4s / T45<=18.56 is met. The application solves the problem that the five-piece optical imaging system in the prior art has a relatively large control field angle, which leads to an increase in the angle of rear-end light, and further causes an increase in stray light.

Description

Technical Field

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

[0002] In modern optical imaging systems, especially in mobile phone cameras, surveillance cameras, and other portable imaging devices, low-cost five-element optical imaging systems are widely favored by major manufacturers. However, with the increasing market demand for ultra-wide-angle imaging systems, the design of five-element optical imaging systems faces even greater challenges.

[0003] Currently, in five-element optical imaging systems, when the field of view is kept within a large range, the angle of light entering the system at a large angle and exiting from the image side increases, leading to more stray light at the edge of the rear lens. This results in excessive ineffective light paths due to stray light reflection, which reduces the final imaging quality of the optical imaging system.

[0004] In other words, the existing five-element optical imaging system has the problem of a large field of view, which leads to an increase in the angle of the back-end light rays and thus an increase in stray light. Summary of the Invention

[0005] The main objective of this invention is to provide an optical imaging system that solves the problem in existing five-element optical imaging systems where a large field of view leads to an increased angle of light at the back end, which in turn causes an increase in stray light.

[0006] To achieve the above objectives, according to one aspect of the present invention, an optical imaging system is provided, comprising a lens barrel and a lens group and a plurality of spacers disposed within the lens barrel. The lens group consists of five lenses, which are sequentially arranged from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, adjacent lenses have an air gap on the optical axis of the optical imaging system. The plurality of spacers includes a first spacer positioned on the image side of the first lens and in contact with its image-side surface, a second spacer positioned on the image side of the second lens and in contact with its image-side surface, a third spacer positioned on the image side of the third lens and in contact with its image-side surface, and a fourth spacer positioned on the image side of the fourth lens and in contact with its image-side surface. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46° ≤ FOV ≤ 180.03°. The inner diameter d4s of the object side surface of the fourth spacer and the air gap T45 between the fourth and fifth lenses on the optical axis satisfy: 12.80 ≤ d4s / T45 ≤ 18.56.

[0007] According to another aspect of the present invention, an optical imaging system is provided, comprising a lens barrel and a lens group and a plurality of spacers disposed within the lens barrel. The lens group consists of five lenses, which are sequentially arranged from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, adjacent lenses have an air gap on the optical axis of the optical imaging system. The plurality of spacers includes a first spacer disposed on the image side of the first lens and in contact with the image side surface of the first lens, a second spacer disposed on the image side of the second lens and in contact with the image side surface of the second lens, a third spacer disposed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacer disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46° ≤ FOV ≤ 180.03°. The inner diameter d3s of the object side surface of the third spacer and the center thickness CT3 of the third lens on the optical axis satisfy: 2.51 ≤ d3s / CT3 ≤ 4.09.

[0008] According to another aspect of the present invention, an optical imaging system is provided, comprising a lens barrel and a lens group and a plurality of spacers disposed within the lens barrel. The lens group consists of five lenses, which are sequentially arranged from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, adjacent lenses have an air gap on the optical axis of the optical imaging system. The plurality of spacers includes a first spacer disposed on the image side of the first lens and in contact with the image side surface of the first lens, a second spacer disposed on the image side of the second lens and in contact with the image side surface of the second lens, a third spacer disposed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth spacer disposed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46° ≤ FOV ≤ 180.03°. The inner 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: -0.59 ≤ d4s × 10 / R8 < 0.10.

[0009] Furthermore, the air gap T12 between the first lens and the second lens on the optical axis satisfies the following condition with respect to the maximum axial thickness CP1 of the first isolator: 28.12≤T12 / CP1≤70.31.

[0010] Furthermore, the inner diameter d0s of the object-side end face of the lens tube satisfies the following relationship with the entrance pupil diameter EPD of the optical imaging system: 4.74≤d0s / EPD≤5.72.

[0011] Furthermore, the effective focal length f1 of the first lens, the center thickness CT1 of the first lens on the optical axis, and the maximum axial thickness CP1 of the first isolator satisfy the following condition: -5.42≤f1 / (CT1+CP1)≤-4.30.

[0012] Furthermore, the air gap T12 between the first lens and the second lens on the optical axis and the distance EP12 between the image side of the first isolator and the object side of the second isolator on the optical axis satisfy the following condition: 1.76≤T12 / EP12≤2.38.

[0013] Furthermore, the outer diameter D1s of the object side of the first isolator, the inner diameter d1s of the object side of the first isolator, and the air gap T12 between the first lens and the second lens on the optical axis satisfy the following: 3.50≤(D1s-d1s) / T12≤4.81.

[0014] Furthermore, the effective focal length f4 of the fourth lens and the distance EP34 between the image side of the third isolator and the object side of the fourth isolator on the optical axis satisfy the following condition: 2.80≤f4 / EP34≤5.52.

[0015] Furthermore, the effective focal length f5 of the fifth lens, the outer diameter D4m of the image-side surface of the fourth isolator, and the inner diameter d4m of the image-side surface of the fourth isolator satisfy the following condition: 1.79≤f5 / (D4m-d4m)≤7.17.

[0016] Furthermore, the inner diameter d3m of the image side of the third isolator and the radius of curvature R7 of the object side of the fourth lens satisfy the following condition: 1.34≤d3m / R7≤2.05.

[0017] Furthermore, the distance between the image side of the first isolator and the object side of the second isolator on the optical axis is less than the distance between the image side of the second isolator and the object side of the third isolator on the optical axis. The combined focal length f12 of the first lens and the second lens satisfies the following relationship with the distance EP12 between the image side of the first isolator and the object side of the second isolator on the optical axis: -6.64≤f12 / EP12≤-3.49.

[0018] Furthermore, the displacement SAG12 of the intersection of the image side of the first lens on the optical axis to the effective half-aperture vertex of the image side of the first lens on the optical axis, the center thickness CT1 of the first lens on the optical axis, and the maximum axial thickness CP1 of the first isolator satisfy the following: 1.57≤SAG12 / (CT1+CP1)≤2.42.

[0019] Furthermore, the multiple isolation elements also include a fourth auxiliary isolation element placed on the image side of the fourth isolation element and in contact with the image side of the fourth isolation element. The maximum axial thickness CP4 of the fourth isolation element, the maximum axial thickness CP4b of the fourth auxiliary isolation element, and the air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy the following: 3.45≤(CP4+CP4b) / T45≤5.79.

[0020] Furthermore, the inner diameter d3s of the object side of the third isolator and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 2.51≤d3s / CT3≤4.09.

[0021] Furthermore, the inner diameter of the object side of the third isolator is greater than the inner diameter of the object side of the second isolator. The maximum axial thickness CP2 of the second isolator, the center thickness CT3 of the third lens on the optical axis, the maximum axial thickness CP3 of the third isolator, and the distance EP23 between the image side of the second isolator and the object side of the third isolator on the optical axis satisfy the following: 1.22≤(CP2+CT3+CP3) / EP23≤2.29.

[0022] Furthermore, the radius of curvature R4 of the image side of the second lens and the radius of curvature R3 of the object side of the second lens satisfy the following condition: 0.94≤R4 / R3≤2.51; the radius of curvature R4 of the image side of the second lens and the inner diameter d2s of the object side of the second isolator satisfy the following condition: 2.10≤R4 / d2s≤5.11.

[0023] Furthermore, the inner diameter of the object-side end face of the lens tube is larger than the inner diameter of the image-side end face of the lens tube, and the outer diameter of the image-side side of the first isolator, the second isolator, the third isolator, and the fourth isolator gradually decreases.

[0024] Furthermore, the air gap T12 between the first and second lenses on the optical axis, the maximum axial thickness CP2 of the second isolator, and the air gap T23 between the second and third lenses on the optical axis satisfy the following condition: 2.72≤T12 / (CP2+T23)≤3.48.

[0025] Applying the technical solution of this invention, the optical imaging system of this application consists of a lens barrel, five lenses disposed within the lens barrel, and multiple isolators. By rationally arranging the positions of the five lenses and the first to fourth isolators, and setting 154.46°≤FOV≤180.03°, it can be seen that the optical imaging system of this application is an ultra-wide-angle optical imaging system. In this case, when large-angle light enters the optical imaging system and exits from the image side, the light angle will increase, resulting in more stray light at the edge of the rear lens. This leads to excessive ineffective light paths generated by stray light reflection, reducing the final imaging quality of the optical imaging system. Therefore, by constraining 12.80≤d4s / T45≤18.56, this application can control the ratio of the inner diameter of the object side of the fourth isolator to the air gap between the fourth and fifth lenses on the optical axis. This allows the fourth isolator to effectively intercept and absorb stray light, reducing the reflection of stray light inside the optical imaging system, avoiding the risk of excessive ineffective light paths affecting imaging quality, and thus ensuring the imaging quality of the optical imaging system. Attached Figure Description

[0026] 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: Figure 1 A dimensioned diagram of an optical imaging system according to an alternative embodiment of the present invention is shown; Figure 2 A schematic diagram of the optical imaging system of Embodiment 1-1 of the present invention is shown; Figure 3 The diagram shows a schematic representation of the optical imaging system according to embodiments 1-2 of the present invention. Figure 4 Schematic diagrams of the optical imaging systems of embodiments 1-3 of the present invention are shown; Figure 5 and Figure 6 The astigmatism curve and magnification chromatic aberration curve of the optical imaging system of Embodiment 1 of the present invention are shown respectively; Figure 7 A schematic diagram of the optical imaging system of Embodiment 2-1 of the present invention is shown; Figure 8 A schematic diagram of the optical imaging system of Embodiment 2-2 of the present invention is shown; Figure 9 Schematic diagrams of the optical imaging systems of embodiments 2-3 of the present invention are shown; Figure 10 and Figure 11 The astigmatism curve and magnification chromatic aberration curve of the optical imaging system of Embodiment 2 of the present invention are shown respectively; Figure 12 A schematic diagram of the optical imaging system of Embodiment 3-1 of the present invention is shown; Figure 13 A schematic diagram of the optical imaging system of Embodiment 3-2 of the present invention is shown; Figure 14 A schematic diagram of the optical imaging system of Embodiment 3-3 of the present invention is shown; Figure 15 and Figure 16 The astigmatism curve and magnification chromatic aberration curve of the optical imaging system of Embodiment 3 of the present invention are shown respectively; Figure 17 The stray light energy diagram of the optical imaging system of Scheme 1 of the present invention is shown when FOV=160.59° and d4s / T45=14.57 is satisfied; Figure 18 The stray light energy diagram of the optical imaging system of Comparative Example 1 is shown when FOV=160.59° and d4s / T45=7.50. Figure 19 The stray light energy diagram of the optical imaging system of Comparative Example 2 is shown when FOV=160.59° and d4s / T45=25.40 are satisfied.

[0027] The above figures include the following reference numerals: P0, Lens tube; E1, First lens; S1, Object-side surface of the first lens; S2, Image-side surface of the first lens; E2, Second lens; S3, Object-side surface of the second lens; S4, Image-side surface of the second lens; E3, Third lens; S5, Object-side surface of the third lens; S6, Image-side surface of the third lens; E4, Fourth lens; S7, Object-side surface of the fourth lens; S8, Image-side surface of the fourth lens; E5, Fifth lens; S9, Object-side surface of the fifth lens; S10, Image-side surface of the fifth lens; P1, First isolator; P2, Second isolator; P3, Third isolator; P3b, Third auxiliary isolator; P4, Fourth isolator; P4b, Fourth auxiliary isolator. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] In this paper, the paraxial region refers to the area near the optical axis. If the lens surface is convex and its location is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and its location 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 based on the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens data in optical software). For the object side, a positive R value indicates a convex surface, and a negative R value indicates a concave surface; for the image side, a positive R value indicates a concave surface, and a negative R value indicates a convex surface.

[0034] In this application, the object side refers to the side of the optical imaging system facing the object being photographed (not shown in the figure), and the image side refers to the side of the optical imaging system facing the imaging plane (not shown in the figure). In the following text, the object side of a lens refers to the surface of the lens facing the object being photographed (not shown in the figure), and the image side of a lens refers to the surface of the lens facing the imaging plane (not shown in the figure). In the structural schematic diagram shown in this application, the left side is the object side, and the right side is the image side.

[0035] To address the problem that existing five-element optical imaging systems have a large control field of view, which leads to an increase in the angle of the back-end light rays and consequently an increase in stray light, this invention provides an optical imaging system.

[0036] like Figures 1 to 17 As shown, in an optional embodiment of this application, an optical imaging system is provided, including a lens barrel and a lens group and multiple isolators disposed in the lens barrel. The lens group consists of five lenses, which are sequentially arranged from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, adjacent lenses have an air gap on the optical axis of the optical imaging system. The multiple isolators include a first isolator placed on the image side of the first lens and in contact with the image side surface of the first lens, and an isolator placed on the second lens... The optical imaging system comprises a second isolator on the image side and in contact with the image side of the second lens, a third isolator on the image side of the third lens and in contact with the image side of the third lens, and a fourth isolator on the image side of the fourth lens and in contact with the image side of the fourth lens; wherein the maximum field of view (FOV) of the optical imaging system satisfies: 154.46°≤FOV≤180.03°; and the inner diameter d4s of the object side of the fourth isolator and the air gap T45 between the fourth and fifth lenses on the optical axis satisfy: 12.80≤d4s / T45≤18.56.

[0037] The optical imaging system of this application consists of a lens barrel, five lenses disposed within the lens barrel, and multiple isolators. By rationally arranging the positions of the five lenses and the first to fourth isolators, and setting 154.46°≤FOV≤180.03°, it can be seen that the optical imaging system of this application is an ultra-wide-angle optical imaging system. In this case, when large-angle light enters the optical imaging system and exits from the image side, the angle of the light increases, resulting in more stray light at the edge of the rear lens. This leads to excessive ineffective light paths due to stray light reflection, reducing the final imaging quality of the optical imaging system. Therefore, by constraining 12.80≤d4s / T45≤18.56, this application can control the ratio of the inner diameter of the object side of the fourth isolator to the air gap between the fourth and fifth lenses on the optical axis. This allows the fourth isolator to effectively intercept and absorb stray light, reducing the reflection of stray light inside the optical imaging system, avoiding the risk of excessive ineffective light paths affecting imaging quality, and thus ensuring the imaging quality of the optical imaging system.

[0038] In addition, please refer to Table 1 below. Figures 17 to 19 As shown, under the premise that the optical imaging system satisfies 154.46°≤FOV≤180.03°, for example, FOV=160.59°, Figure 17 The stray light energy diagram of the optical imaging system of Scheme 1 of the present invention is shown when d4s / T45=14.57 is satisfied; Figure 18 The stray light energy diagram of the optical imaging system of Comparative Example 1 is shown when d4s / T45=7.50 is satisfied; Figure 19 The stray light energy diagram of the optical imaging system of Comparative Example 2 is shown when d4s / T45=25.40 is satisfied.

[0039] Depend on Figures 17 to 19 As shown, when the optical imaging system satisfies d4s / T45=14.57, stray light is less and has lower energy, with a stray light energy of 7.6E-6, resulting in good overall performance. When the optical imaging system satisfies d4s / T45=7.50, stray light is more and has higher energy, with a stray light energy of 5.2E-4, resulting in poor overall performance. When the optical imaging system satisfies d4s / T45=25.40, stray light is more and has higher energy, with a stray light energy of 1.6E-3, resulting in poor overall performance. Therefore, it can be seen that when 154.46°≤FOV≤180.03° and d4s / T45 is in the range of 12.80 to 18.56, stray light is less and has lower energy, resulting in the best overall performance. Therefore, by constraining 154.46°≤FOV≤180.03° and 12.80≤d4s / T45≤18.56, this application enables the fourth isolator to effectively intercept and absorb stray light, reduce the reflection of stray light inside the optical imaging system, avoid the risk of too many invalid optical paths affecting the imaging quality, and thus ensure the imaging quality of the optical imaging system.

[0040] Table 1

[0041] It's important to note that ineffective light rays refer to those rays that do not participate in the imaging process. This includes light rays that enter the optical imaging system but are not focused on the imaging surface, or light rays that are scattered, reflected, or absorbed within the optical imaging system. Ineffective light rays can be caused by physical limitations in the design, or by factors such as unevenness, dust, scratches, or uneven coating on the lens surface. Ineffective light rays not only fail to improve image quality but may also lead to undesirable effects such as image blurring, reduced contrast, or the production of light spots and glare.

[0042] In this embodiment, the plurality of isolation members also includes a fourth auxiliary isolation member that is placed on the image side of the fourth isolation member and in contact with the image side surface of the fourth isolation member.

[0043] In this embodiment, the air gap T12 between the first lens and the second lens on the optical axis satisfies the following condition with respect to the maximum axial thickness CP1 of the first isolator: 28.12 ≤ T12 / CP1 ≤ 70.31. By controlling this condition, the air gap between the first lens and the second lens on the optical axis can be controlled, thereby appropriately adjusting the maximum axial thickness of the first isolator to ensure the assembly strength of the front-end structure and improve its assembly stability. At the same time, constraining and controlling the maximum axial thickness of the first isolator can effectively correct field curvature and reduce the risk of stray light, which is beneficial to ensuring the imaging quality of the optical imaging system.

[0044] In this embodiment, the inner diameter d0s of the object-side end face of the lens barrel and the entrance pupil diameter EPD of the optical imaging system satisfy the following ratio: 4.74 ≤ d0s / EPD ≤ 5.72. The ratio of the inner diameter of the object-side end face of the lens barrel to the entrance pupil diameter of the optical imaging system affects the illuminance of the imaging surface. Under the same object-side illumination conditions, a larger ratio results in more uniform illuminance on the imaging surface. By controlling this condition within this range, a larger inner diameter of the object-side end face of the lens barrel can be ensured, which is beneficial for collecting more light into the optical imaging system. Simultaneously, a reasonable entrance pupil diameter ensures a more uniform distribution of light on the imaging surface. Furthermore, constraining this ratio helps the optical imaging system maintain a large field of view while reducing edge aberrations, thus balancing field size and image quality.

[0045] In this embodiment, the effective focal length f1 of the first lens, the center thickness CT1 of the first lens on the optical axis, and the maximum axial thickness CP1 of the first isolator satisfy the condition: -5.42 ≤ f1 / (CT1+CP1) ≤ -4.30. By controlling this condition, the effective focal length of the first lens can be controlled, thereby effectively controlling the shape of the first lens and constraining the field of view of the optical imaging system, thus matching the ultra-wide-angle requirements of the optical imaging system. At the same time, it also limits the center thickness of the first lens on the optical axis and the maximum axial thickness of the first isolator, which helps to ensure the assembly stability of the first and second lenses, reduces the risk of deformation of the first lens, second lens, and first isolator after assembly, and thus improves the assembly stability of the optical imaging system.

[0046] In this embodiment, the air gap T12 between the first and second lenses on the optical axis and the distance EP12 between the image side of the first isolator and the object side of the second isolator on the optical axis satisfy the condition: 1.76 ≤ T12 / EP12 ≤ 2.38. By controlling this condition, the relationship between the air gap between the first and second lenses on the optical axis and the distance between the image side of the first isolator and the object side of the second isolator on the optical axis can be controlled within a reasonable range. This effectively controls the edge thickness of the second lens and the air gap between the first and second lenses on the optical axis, thereby improving the limiting process during the production of the second lens. At the same time, it also ensures the radial bearing width of the structure between the second and third lenses.

[0047] In this embodiment, the outer diameter D1s of the object-side surface of the first isolator, the inner diameter d1s of the object-side surface of the first isolator, and the air gap T12 between the first lens and the second lens on the optical axis satisfy the following condition: 3.50 ≤ (D1s - d1s) / T12 ≤ 4.81. The difference between the outer diameter and the inner diameter of the object-side surface of the first isolator determines the radial contact width between the first isolator and the image-side surface of the first lens, and thus determines the contact area. By controlling this difference within a reasonable range, it is beneficial to avoid D1s - d1s being too large, resulting in an excessively large radial width of the first isolator, which would make the first isolator prone to deformation under high temperature and high humidity conditions, thereby generating the risk of stray light. At the same time, it can also avoid D1s - d1s being too small, resulting in an excessively small radial width of the first isolator, which would affect its stable contact with the first lens and the risk of affecting the assembly stability. Therefore, controlling the relationship between the difference between the outer and inner diameters of the object side of the first isolator and the air gap between the first and second lenses on the optical axis effectively ensures the rationality of the size of the first isolator, thereby ensuring a large contact area between it and the first lens, ensuring the assembly stability of the optical imaging system. At the same time, reasonably constraining the air gap between the first and second lenses on the optical axis can also adjust the field curvature, thereby improving the performance and yield of the optical imaging system.

[0048] In this embodiment, the effective focal length f4 of the fourth lens and the distance EP34 between the image-side surface of the third isolator and the object-side surface of the fourth isolator on the optical axis satisfy the condition: 2.80 ≤ f4 / EP34 ≤ 5.52. By controlling this condition, the distance between the image-side surface of the third isolator and the object-side surface of the fourth isolator on the optical axis can be constrained. This facilitates reasonable control of the edge thickness of the fourth lens, strengthens the bearing capacity of the edge structure of the fourth lens, reduces the assembly difficulty and risk of the fourth lens, and also allows adjustment of the effective focal length of the fourth lens. This helps to improve the ability of the fourth lens to receive light in the optical imaging system, reduces the risk of imaging distortion, and results in higher imaging quality of the optical imaging system.

[0049] In this embodiment, the effective focal length f5 of the fifth lens and the outer diameter D4m and inner diameter d4m of the image-side surface of the fourth isolator satisfy the following condition: 1.79 ≤ f5 / (D4m-d4m) ≤ 7.17. The effective focal length of the fifth lens determines its shape, and the difference between the outer diameter and inner diameter of the image-side surface of the fourth isolator determines the contact area between the fourth isolator and the object-side surface of the fifth lens. By controlling this condition, reasonably controlling this ratio helps ensure the feasibility of processing the fifth lens and also ensures the stability of the fourth lens, fourth isolator, and fifth lens during assembly.

[0050] In this embodiment, the inner diameter d3m of the image-side surface of the third isolator and the radius of curvature R7 of the object-side surface of the fourth lens satisfy the following ratio: 1.34 ≤ d3m / R7 ≤ 2.05. By controlling the ratio of the inner diameter of the image-side surface of the third isolator to the radius of curvature of the object-side surface of the fourth lens, it is helpful to reduce the surface shape sensitivity of the fourth lens and appropriately increase the contact area between the fourth lens and the third isolator. This not only enhances the assembly stability of the fourth lens and the third isolator but also helps the third isolator to intercept stray light, thereby reducing stray light in the optical imaging system.

[0051] In this embodiment, the distance between the image-side surface of the first isolator and the object-side surface of the second isolator on the optical axis is less than the distance between the image-side surface of the second isolator and the object-side surface of the third isolator on the optical axis. The combined focal length f12 of the first lens and the second lens satisfies the condition -6.64 ≤ f12 / EP12 ≤ -3.49 between the distance between the image-side surface of the first isolator and the object-side surface of the second isolator on the optical axis. By controlling this condition and the spacing distance of the front isolators, it is beneficial to ensure the structural strength of the edge portion of the second lens, ensure the stable support of the second lens in the lens barrel, reduce the assembly difficulty and assembly risk of the second lens, and at the same time constrain the combined focal length of the first lens and the second lens, which helps to improve the stability of the light reception of the front first and second lenses and the rear lens, thereby improving the imaging quality and reducing imaging distortion.

[0052] In this embodiment, the displacement SAG12 of the effective half-aperture vertex of the image-side surface of the first lens on the optical axis, the center thickness CT1 of the first lens on the optical axis, and the maximum axial thickness CP1 of the first spacer satisfy the following condition: 1.57≤SAG12 / (CT1+CP1)≤2.42. By controlling this conditional expression, it is beneficial to reasonably set the parameters in the conditional expression, which is beneficial to the processing and forming of the first lens and the first spacer, and thus helps to ensure the smooth surface shape of the image-side surface of the first lens.

[0053] In this embodiment, the maximum axial thickness CP4 of the fourth isolator, the maximum axial thickness CP4b of the fourth auxiliary isolator, and the air gap T45 between the fourth and fifth lenses on the optical axis satisfy the following condition: 3.45 ≤ (CP4 + CP4b) / T45 ≤ 5.79. By controlling this condition, the relationship between the sum of the maximum axial thicknesses of the fourth isolator and the fourth auxiliary isolator, and the air gap between the fourth and fifth lenses on the optical axis is controlled. This helps to constrain the thickness of the fourth isolator and the fourth auxiliary isolator, ensuring the assembly strength of the fourth lens, the fifth lens, the fourth isolator, and the fourth auxiliary isolator, improving the assembly stability of the rear end of the optical imaging system. At the same time, the fourth isolator and the fourth auxiliary isolator can also effectively intercept stray light, thereby improving the imaging quality of the optical imaging system.

[0054] In this embodiment, the inner diameter d3s of the object-side surface of the third isolator and the center thickness CT3 of the third lens on the optical axis satisfy the condition: 2.51 ≤ d3s / CT3 ≤ 4.09. By controlling this condition, controlling the inner diameter of the object-side surface of the third isolator helps to intercept stray light from the front end, thereby improving the imaging quality of the optical imaging system. At the same time, it can also control the center thickness of the third lens on the optical axis, which is beneficial to the processing and shaping of the third lens, and can also ensure the stable support between the third lens and the third isolator, thereby ensuring the assembly stability of the optical imaging system.

[0055] In this embodiment, the inner diameter of the object-side surface of the third isolator is larger than that of the object-side surface of the second isolator. The maximum axial thickness CP2 of the second isolator, the center thickness CT3 of the third lens on the optical axis, the maximum axial thickness CP3 of the third isolator, and the distance EP23 between the image-side surface of the second isolator and the object-side surface of the third isolator on the optical axis satisfy the following condition: 1.22≤(CP2+CT3+CP3) / EP23≤2.29. By controlling this condition, the maximum axial thickness of the second isolator, the center thickness of the third lens on the optical axis, the maximum axial thickness of the third isolator, and the distance between the image-side surface of the second isolator and the object-side surface of the third isolator on the optical axis can be controlled. This facilitates the rational configuration of the distance between the second and third lenses and the size of the isolator between the second and third lenses, compressing the length of the optical imaging system in the optical axis direction, thereby achieving miniaturization of the optical imaging system. Furthermore, it also allows for the rational allocation of the maximum axial thickness of the third isolator and the center thickness of the third lens on the optical axis, thereby achieving optimal assembly process and improving the assembly stability of the optical imaging system.

[0056] In this embodiment, the radius of curvature R4 of the image-side surface of the second lens and the radius of curvature R3 of the object-side surface of the second lens satisfy the following condition: 0.94 ≤ R4 / R3 ≤ 2.51; the radius of curvature R4 of the image-side surface of the second lens and the inner diameter d2s of the object-side surface of the second isolator satisfy the following condition: 2.10 ≤ R4 / d2s ≤ 5.11. By controlling the above conditions, the ratio of the radii of curvature of the image-side surface to the object-side surface of the second lens is controlled, which is beneficial for controlling the shape of the second lens. At the same time, controlling the ratio of the radius of curvature of the image-side surface of the second lens to the inner diameter of the object-side surface of the second isolator is beneficial for improving the assembly stability of the second lens.

[0057] In this embodiment, the inner diameter of the object-side end face of the lens barrel is larger than the inner diameter of the image-side end face of the lens barrel. The outer diameters of the image-side surfaces of the first, second, third, and fourth isolators gradually decrease. By setting the inner diameter of the object-side end face of the lens barrel to be larger than the inner diameter of the image-side end face, more light can enter the optical imaging system, ensuring a sufficient field of view to meet the ultra-wide-angle requirements of the optical imaging system. At the same time, by setting the outer diameters of the image-side surfaces of the first to fourth isolators to gradually decrease, the miniaturization of the optical imaging system is achieved while ensuring the stable support of each lens and isolator in the optical imaging system.

[0058] In this embodiment, the air gap T12 between the first and second lenses on the optical axis, the maximum axial thickness CP2 of the second isolator, and the air gap T23 between the second and third lenses on the optical axis satisfy the following condition: 2.72 ≤ T12 / (CP2+T23) ≤ 3.48. By controlling this condition, the relationship between the air gap between the first and second lenses on the optical axis, the maximum axial thickness of the second isolator, and the air gap between the second and third lenses on the optical axis is kept within a reasonable range. This effectively controls the edge thickness, center thickness, and spacing distance between adjacent lenses of the first, second, and third lenses, improving the limiting process during lens production. Simultaneously, it ensures the bearing width between lenses, reduces cantilever length, and avoids stray light caused by deformation of long cantilever arms under high temperature and high humidity conditions.

[0059] In this embodiment, the first lens has negative optical power, its object-side surface is convex, and its image-side surface is concave; the second lens has optical power, its object-side surface is convex, and its image-side surface is concave; the third lens has optical power; the fourth lens has positive optical power, its object-side surface is convex; and the fifth lens has positive optical power, its object-side surface is convex, and its image-side surface is concave. By rationally planning the optical power and surface shape of each lens, it is beneficial to control the light path, eliminate aberrations, and ensure image quality.

[0060] In another optional embodiment of this application, an optical imaging system is provided, including a lens barrel and a lens group and multiple isolators disposed in the lens barrel. The lens group consists of five lenses, which are arranged sequentially from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, there is an air gap between adjacent lenses on the optical axis of the optical imaging system. The multiple isolators include a first isolator placed on the image side of the first lens and in contact with the image side surface of the first lens, a second isolator placed on the image side of the second lens and in contact with the image side surface of the second lens, a third isolator placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth isolator placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46°≤FOV≤180.03°. The inner diameter d3s of the object side surface of the third isolator and the center thickness CT3 of the third lens on the optical axis satisfy: 2.51≤d3s / CT3≤4.09.

[0061] The optical imaging system of this application consists of a lens barrel, five lenses disposed within the lens barrel, and multiple isolators. By rationally arranging the positions of the five lenses and the first to fourth isolators, and setting 154.46°≤FOV≤180.03°, it can be seen that the optical imaging system of this application is an ultra-wide-angle optical imaging system. In this case, when large-angle light enters the optical imaging system and exits from the image side, the angle of the light increases, resulting in more stray light at the edge of the rear lens. This leads to excessive ineffective light paths generated by stray light reflection, reducing the final imaging quality of the optical imaging system. Therefore, by constraining 2.51≤d3s / CT3≤4.09, this application controls the inner diameter of the object side of the third isolator, which helps to intercept stray light paths from the front end, thereby improving the imaging quality of the optical imaging system. At the same time, it can also control the center thickness of the third lens on the optical axis, which is beneficial to the processing and shaping of the third lens, and can also ensure the stable support between the third lens and the third isolator.

[0062] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0063] In another optional embodiment of this application, an optical imaging system is also provided, including a lens barrel and a lens group and multiple isolators disposed in the lens barrel. The lens group consists of five lenses, which are arranged sequentially from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. Among the first to fifth lenses, there is an air gap between adjacent lenses on the optical axis of the optical imaging system. The multiple isolators include a first isolator placed on the image side of the first lens and in contact with the image side surface of the first lens, a second isolator placed on the image side of the second lens and in contact with the image side surface of the second lens, a third isolator placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth isolator placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46°≤FOV≤180.03°. The inner diameter d4s of the object side surface of the fourth isolator and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.59≤d4s×10 / R8<0.10.

[0064] The optical imaging system of this application consists of a lens barrel, five lenses disposed within the lens barrel, and multiple isolators. By rationally arranging the positions of the five lenses and the first to fourth isolators, and setting 154.46°≤FOV≤180.03°, it is evident that the optical imaging system of this application is an ultra-wide-angle optical imaging system. In this case, when large-angle light enters the optical imaging system and exits from the image side, the light angle increases, leading to an increase in stray light at the edge of the rear lens. This, in turn, results in excessive ineffective light paths due to stray light reflection, reducing the final imaging quality of the optical imaging system. Therefore, this application constrains -0.59≤d4s×10 / R8<0.10, ensuring that the inner diameter of the object-side surface of the fourth isolator meets the requirements for intercepting front-end stray light. This helps improve stray light quality and thus ensures the imaging quality of the optical imaging system. Simultaneously, it also ensures the size of the radius of curvature of the image-side surface of the fourth lens, which helps ensure the rationality of the fourth lens's surface shape and the feasibility of its fabrication.

[0065] Of course, this embodiment may also include other parametric expressions as described in the above embodiments, which will not be elaborated here.

[0066] Optionally, the optical imaging system described above may also include protective glass for protecting the photosensitive element located on the imaging surface.

[0067] The optical imaging system in this application may employ multiple lenses, such as the five 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.

[0068] Figure 1 A schematic diagram showing the dimensions of an optical imaging system according to this application is provided. Figure 1 The figures clearly indicate parameters such as d2s, d3s, d3m, d4s, d4m, D4m, CP1, EP12, CP2, EP23, CP3, EP34, CP4, CP4b, d0s, D1s, d1s, and SAG12 to provide a clear and intuitive understanding of their meaning. To facilitate the description of the optical imaging system and the specific lens profiles, these parameters will not be shown in the accompanying figures when describing specific embodiments.

[0069] The following description, with reference to the accompanying drawings, further illustrates examples of specific surface shapes and parameters applicable to the optical imaging systems described above.

[0070] It should be noted that in the following Embodiment 1, there are three examples: Embodiment 1-1, Embodiment 1-2, and Embodiment 1-3; in Embodiment 2, there are three examples: Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3; and in Embodiment 3, there are three examples: Embodiment 3-1, Embodiment 3-2, and Embodiment 3-3. In the three examples within the same embodiment, the parameters such as the radius of curvature, center thickness, and spacing between lenses, as well as the higher-order coefficients, of the optical imaging system are the same. However, the parameters such as the thickness, inner diameter, and outer diameter of the lens barrel, the first spacer, and the fourth spacer are different.

[0071] It should be noted that any one of the examples in Embodiments 1 to 3 described below is applicable to all implementations of this application.

[0072] Example 1

[0073] like Figures 2 to 6 As shown, the optical imaging system of Embodiment 1 is described. Figure 2 A schematic diagram of the optical imaging system of Embodiment 1-1 is shown. Figure 3 A schematic diagram of the optical imaging system of Embodiments 1-2 is shown. Figure 4 A schematic diagram of the optical imaging system of Examples 1-3 is shown.

[0074] like Figures 2 to 4 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first isolator P1, a second lens E2, a second isolator P2, a third lens E3, a third isolator P3, a fourth lens E4, a fourth isolator P4, and a fifth lens E5 arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0075] like Figure 2 The diagram shows a schematic of the optical imaging system of Embodiment 1-1. In this example, a third auxiliary isolation member P3b is also provided on the image side of the third isolation member P3, and a fourth auxiliary isolation member P4b is also provided on the image side of the fourth isolation member P4. The object side and image side of the first isolation member P1 are in contact with the image side S2 of the first lens and the object side S3 of the second lens, respectively. The object side and image side of the second isolation member P2 are in 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 isolation member P3 are in contact with the image side S6 of the third lens and the object side of the third auxiliary isolation member P3b, respectively, and the image side of the third auxiliary isolation member P3b is in contact with the object side S7 of the fourth lens. The object side and image side of the fourth isolation member P4 are in contact with the image side S8 of the fourth lens and the object side of the fourth auxiliary isolation member P4b, respectively, and the image side of the fourth auxiliary isolation member P4b is in contact with the object side S9 of the fifth lens.

[0076] like Figure 3 The diagram shown is a structural schematic of the optical imaging system of Embodiment 1-2. The bearing and contact methods of each isolation component are the same as in Embodiment 1-1, and can be referred to the relevant descriptions in Embodiment 1-1, which will not be repeated here.

[0077] like Figure 4 The diagram shows the structural schematics of the optical imaging systems in Embodiments 1-3. Embodiments 1-3 differ from Embodiment 1-1 in that the third auxiliary isolator P3b and the fourth auxiliary isolator P4b are not provided. In this case, the object-side and image-side of the third isolator P3 contact the image-side S6 of the third lens and the object-side S7 of the fourth lens, respectively; the object-side and image-side of the fourth isolator P4 contact the image-side S8 of the fourth lens and the object-side S9 of the fifth lens, respectively. The contact methods of the remaining isolators are the same as in Embodiment 1-1, and can be referred to the relevant descriptions in Embodiment 1-1, which will not be repeated here.

[0078] In summary, the structural parameters of the optical imaging system of Embodiment 1 under Embodiments 1-1, 1-2, and 1-3 are shown in Table 2, with units in millimeters (mm).

[0079] Table 2

[0080] In Embodiment 1, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The object-side surface S5 of the third lens is convex, and the image-side surface S6 of the third lens is convex. The object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave.

[0081] In Embodiment 1, the effective focal length f of the optical imaging system is 1.21 mm, the effective focal length f1 of the first lens is -2.25 mm, the effective focal length f2 of the second lens is -175.94 mm, the effective focal length f3 of the third lens is 20.73 mm, the effective focal length f4 of the fourth lens is 2.98 mm, the effective focal length f5 of the fifth lens is 3.01 mm, the combined focal length f12 of the first and second lenses is -1.80 mm, the entrance pupil diameter EPD of the optical imaging system is 1.10 mm, the maximum field of view FOV of the optical imaging system is 180.03°, and the displacement SAG12 from the intersection of the image-side surface of the first lens on the optical axis to the effective half-aperture vertex of the image-side surface of the first lens on the optical axis is 1.02 mm.

[0082] Table 3 shows the basic structural parameters of the optical imaging system of Embodiment 1, where the units for radius of curvature and thickness / distance are millimeters (mm). In the table below, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, located between the third lens E3 and the fourth lens E4. S11 and S12 (not shown in the figure) can be the object-side and image-side of the filter or the object-side and image-side of the protective glass.

[0083] Table 3

[0084] In Embodiment 1, the object-side surface and image-side surface of the first lens E1 to the fifth lens E5 are both aspherical surfaces. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula: Formula (1).

[0085] 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 3 above; k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 4 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical mirror S1-S10 in Example 1.

[0086] Table 4

[0087] Figure 5 The astigmatism curves of the optical imaging system of Embodiment 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6 The magnification chromatic aberration curve of the optical imaging system of Embodiment 1 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0088] according to Figure 5 and Figure 6 As can be seen, the optical imaging system given in Example 1 can achieve good imaging quality.

[0089] Example 2

[0090] like Figures 7 to 11 As shown, the optical imaging system of Embodiment 2 is described. Figure 7 A schematic diagram of the optical imaging system of Embodiment 2-1 is shown. Figure 8 A schematic diagram of the optical imaging system of Embodiment 2-2 is shown. Figure 9 A schematic diagram of the optical imaging system of Embodiments 2-3 is shown.

[0091] like Figures 7 to 9 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first isolator P1, a second lens E2, a second isolator P2, a third lens E3, a third isolator P3, a fourth lens E4, a fourth isolator P4, a fourth auxiliary isolator P4b, and a fifth lens E5, which are arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0092] like Figure 7 The diagram shows a schematic of the optical imaging system of Embodiment 2-1. In this example, a third auxiliary isolation member P3b is also provided on the image side of the third isolation member P3. The object side and image side of the first isolation member P1 are in contact with the image side S2 of the first lens and the object side S3 of the second lens, respectively. The object side and image side of the second isolation member P2 are in 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 isolation member P3 are in contact with the image side S6 of the third lens and the object side of the third auxiliary isolation member P3b, respectively, and the image side of the third auxiliary isolation member P3b is in contact with the object side S7 of the fourth lens. The object side and image side of the fourth isolation member P4 are in contact with the image side S8 of the fourth lens and the object side of the fourth auxiliary isolation member P4b, respectively, and the image side of the fourth auxiliary isolation member P4b is in contact with the object side S9 of the fifth lens.

[0093] like Figure 8 The diagram shown is a schematic representation of the optical imaging system of Embodiment 2-2. The contact and abutment methods of each isolation component are the same as in Embodiment 2-1, and can be found in the relevant description in Embodiment 2-1, which will not be repeated here.

[0094] like Figure 9 The diagram shown is a schematic representation of the optical imaging system in Embodiment 2-3. Embodiment 2-3 differs from Embodiment 2-1 in that the third auxiliary isolator P3b is not provided. In this case, the object-side and image-side of the third isolator P3 contact the image-side S6 of the third lens and the object-side S7 of the fourth lens, respectively. The contact methods of the remaining isolators are the same as in Embodiment 2-1, and can be found in the relevant descriptions in Embodiment 2-1, which will not be repeated here.

[0095] In summary, the structural parameters of the optical imaging system of Embodiment 2 under Embodiments 2-1, 2-2, and 2-3 are shown in Table 5, with units of millimeters (mm).

[0096] Table 5

[0097] In Embodiment 2, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The object-side surface S5 of the third lens is concave, and the image-side surface S6 of the third lens is concave. The object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is concave. The object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave.

[0098] In Embodiment 2, the effective focal length f of the optical imaging system is 1.41 mm, the effective focal length f1 of the first lens is -2.41 mm, the effective focal length f2 of the second lens is 10.08 mm, the effective focal length f3 of the third lens is -42.17 mm, the effective focal length f4 of the fourth lens is 3.07 mm, the effective focal length f5 of the fifth lens is 3.12 mm, the combined focal length f12 of the first and second lenses is -2.83 mm, the entrance pupil diameter EPD of the optical imaging system is 1.28 mm, the maximum field of view FOV of the optical imaging system is 154.46°, and the displacement SAG12 from the intersection of the image-side surface of the first lens on the optical axis to the effective half-aperture vertex of the image-side surface of the first lens on the optical axis is 0.88 mm.

[0099] Table 6 shows the basic structural parameters of the optical imaging system of Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm). In the table below, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, located between the third lens E3 and the fourth lens E4. S11 and S12 (not shown in the figure) can be the object-side and image-side of the filter or the object-side and image-side of the protective glass.

[0100] Table 6

[0101] Table 7 below shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical lens S1-S10 in Example 2. The surface shape of each aspherical lens is defined according to formula (1) in Example 1.

[0102] Table 7

[0103] Figure 10 The astigmatism curves of the optical imaging system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 11 The magnification chromatic aberration curve of the optical imaging system of Embodiment 2 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0104] according to Figure 10and Figure 11 It can be seen that the optical imaging system given in Example 2 can achieve good imaging quality.

[0105] Example 3

[0106] like Figures 12 to 16 As shown, the optical imaging system of Embodiment 3 is described. Figure 12 A schematic diagram of the optical imaging system of Embodiment 3-1 is shown. Figure 13 A schematic diagram of the optical imaging system of Embodiment 3-2 is shown. Figure 14 A schematic diagram of the optical imaging system of Embodiment 3-3 is shown.

[0107] like Figures 12 to 14 As shown, the optical imaging system includes a lens barrel P0 and a first lens E1, a first isolator P1, a second lens E2, a second isolator P2, a third lens E3, a third isolator P3, a fourth lens E4, a fourth isolator P4, a fourth auxiliary isolator P4b, and a fifth lens E5, which are arranged sequentially along the optical axis from the object side to the image side in the lens barrel P0.

[0108] like Figure 12 The diagram shows a schematic of the optical imaging system of Embodiment 3-1. In this example, a third auxiliary isolation member P3b is also provided on the image side of the third isolation member P3. The object side and image side of the first isolation member P1 are in contact with the image side S2 of the first lens and the object side S3 of the second lens, respectively. The object side and image side of the second isolation member P2 are in 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 isolation member P3 are in contact with the image side S6 of the third lens and the object side of the third auxiliary isolation member P3b, respectively, and the image side of the third auxiliary isolation member P3b is in contact with the object side S7 of the fourth lens. The object side and image side of the fourth isolation member P4 are in contact with the image side S8 of the fourth lens and the object side of the fourth auxiliary isolation member P4b, respectively, and the image side of the fourth auxiliary isolation member P4b is in contact with the object side S9 of the fifth lens.

[0109] like Figure 13 The diagram shown is a structural schematic of the optical imaging system of Embodiment 3-2. The bearing and contact methods of each isolation component 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.

[0110] like Figure 14The diagram shown is a schematic representation of the optical imaging system in Embodiment 3-3. Embodiment 3-3 differs from Embodiment 3-1 in that the third auxiliary isolator P3b is not provided. In this case, the object-side and image-side of the third isolator P3 contact the image-side S6 of the third lens and the object-side S7 of the fourth lens, respectively. The contact methods of the remaining isolators are the same as in Embodiment 3-1, and can be found in the relevant descriptions in Embodiment 3-1, which will not be repeated here.

[0111] In summary, the structural parameters of the optical imaging system of Embodiment 3 under Embodiments 3-1, 3-2, and 3-3 are shown in Table 8, with units of millimeters (mm).

[0112] Table 8

[0113] In Embodiment 3, the object-side surface S1 of the first lens is convex, and the image-side surface S2 of the first lens is concave. The object-side surface S3 of the second lens is convex, and the image-side surface S4 of the second lens is concave. The object-side surface S5 of the third lens is concave, and the image-side surface S6 of the third lens is convex. The object-side surface S7 of the fourth lens is convex, and the image-side surface S8 of the fourth lens is convex. The object-side surface S9 of the fifth lens is convex, and the image-side surface S10 of the fifth lens is concave.

[0114] In Embodiment 3, the effective focal length f of the optical imaging system is 1.37 mm, the effective focal length f1 of the first lens is -2.23 mm, the effective focal length f2 of the second lens is 12.32 mm, the effective focal length f3 of the third lens is 225.02 mm, the effective focal length f4 of the fourth lens is 3.07 mm, the effective focal length f5 of the fifth lens is 3.21 mm, the combined focal length f12 of the first and second lenses is -2.35 mm, the entrance pupil diameter EPD of the optical imaging system is 1.25 mm, the maximum field of view FOV of the optical imaging system is 160.59°, and the displacement SAG12 from the intersection of the image-side surface of the first lens on the optical axis to the effective half-aperture vertex of the image-side surface of the first lens on the optical axis is 0.85 mm.

[0115] Table 9 shows the basic structural parameters of the optical imaging system of Embodiment 3, where the units for radius of curvature and thickness / distance are millimeters (mm). In the table below, OBJ (not shown in the figure) is the object distance. STO (not shown in the figure) is the aperture stop, located between the third lens E3 and the fourth lens E4. S11 and S12 (not shown in the figure) can be the object-side and image-side of the filter or the object-side and image-side of the protective glass.

[0116] Table 9

[0117] Table 10 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 that can be used for each aspherical lens S1-S10 in Example 3. The surface shape of each aspherical lens is defined according to formula (1) in Example 1.

[0118] Table 10

[0119] Figure 15 The astigmatism curves of the optical imaging system of Embodiment 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 16 The magnification chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0120] according to Figure 15 and Figure 16 As can be seen, the optical imaging system given in Example 3 can achieve good imaging quality.

[0121] In summary, Examples 1 to 3 satisfy the relationships shown in Table 11.

[0122] Table 11

[0123] Table 12 shows some parameters of the optical imaging systems of Embodiments 1 to 3. Wherein, f is the effective focal length of the optical imaging 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, f12 is the combined focal length of the first and second lenses, EPD is the entrance pupil diameter of the optical imaging system, FOV is the maximum field of view of the optical imaging system, and SAG12 is the displacement on the optical axis from the intersection of the image-side surface of the first lens on the optical axis to the effective half-aperture vertex of the image-side surface of the first lens.

[0124] Table 12

[0125] 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 imaging system described above.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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 imaging system, characterized in that, Includes a lens barrel and a lens assembly and multiple spacers disposed within the lens barrel. The lens group consists of five lenses with optical power, which are arranged in order from the object side to the image side as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; among the first to the fifth lenses, there is an air gap between adjacent lenses on the optical axis of the optical imaging system; The plurality of isolation members include a first isolation member placed on the image side of the first lens and in contact with the image side surface of the first lens, a second isolation member placed on the image side of the second lens and in contact with the image side surface of the second lens, a third isolation member placed on the image side of the third lens and in contact with the image side surface of the third lens, and a fourth isolation member placed on the image side of the fourth lens and in contact with the image side surface of the fourth lens. The first lens has negative optical power, the object side of the first lens is convex, and the image side of the first lens is concave. At least one of the second lens and the third 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 concave. The fourth lens has positive optical power, and the object side of the fourth lens is convex. The fifth lens has positive optical power, the object side of the fifth lens is convex, and the image side of the fifth lens is concave. The maximum field of view (FOV) of the optical imaging system satisfies: 154.46°≤FOV≤180.03°; the inner diameter d4s of the object side of the fourth isolator and the air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy: 12.80≤d4s / T45≤18.56; The radius of curvature R4 of the image side of the second lens and the radius of curvature R3 of the object side of the second lens satisfy the following condition: 0.94≤R4 / R3≤2.

51.

2. The optical imaging system according to claim 1, characterized in that, The air gap T12 between the first lens and the second lens on the optical axis satisfies the following condition with respect to the maximum axial thickness CP1 of the first isolator: 28.12≤T12 / CP1≤70.

31.

3. The optical imaging system according to claim 1, characterized in that, The inner diameter d0s of the object-side end face of the lens barrel and the entrance pupil diameter EPD of the optical imaging system satisfy the following condition: 4.74≤d0s / EPD≤5.

72.

4. The optical imaging system according to claim 1, characterized in that, The effective focal length f1 of the first lens, the center thickness CT1 of the first lens on the optical axis and the maximum axial thickness CP1 of the first isolator satisfy the following condition: -5.42≤f1 / (CT1+CP1)≤-4.

30.

5. The optical imaging system according to claim 1, characterized in that, The air gap T12 between the first lens and the second lens on the optical axis and the distance EP12 between the image side of the first isolator and the object side of the second isolator on the optical axis satisfy the following: 1.76≤T12 / EP12≤2.

38.

6. The optical imaging system according to claim 1, characterized in that, The outer diameter D1s of the object side of the first isolator, the inner diameter d1s of the object side of the first isolator, and the air gap T12 between the first lens and the second lens on the optical axis satisfy the following: 3.50≤(D1s-d1s) / T12≤4.

81.

7. The optical imaging system according to claim 1, characterized in that, The effective focal length f4 of the fourth lens and the distance EP34 between the image side of the third isolator and the object side of the fourth isolator on the optical axis satisfy the following condition: 2.80≤f4 / EP34≤5.

52.

8. The optical imaging system according to claim 1, characterized in that, The effective focal length f5 of the fifth lens, the outer diameter D4m of the image side of the fourth isolator, and the inner diameter d4m of the image side of the fourth isolator satisfy the following condition: 1.79≤f5 / (D4m-d4m)≤7.

17.

9. The optical imaging system according to claim 1, characterized in that, The inner diameter d3m of the image side of the third isolator and the radius of curvature R7 of the object side of the fourth lens satisfy the following condition: 1.34≤d3m / R7≤2.

05.

10. The optical imaging system according to claim 1, characterized in that, The distance between the image side of the first isolator and the object side of the second isolator on the optical axis is less than the distance between the image side of the second isolator and the object side of the third isolator on the optical axis. The combined focal length f12 of the first lens and the second lens satisfies the following relationship with the distance EP12 between the image side of the first isolator and the object side of the second isolator on the optical axis: -6.64≤f12 / EP12≤-3.

49.

11. The optical imaging system according to claim 1, characterized in that, The displacement SAG12 of the point where the image side of the first lens intersects the optical axis to the effective half-aperture vertex of the image side of the first lens on the optical axis, and the central thickness CT1 of the first lens on the optical axis and the maximum axial thickness CP1 of the first isolator satisfy the following: 1.57≤SAG12 / (CT1+CP1)≤2.

42.

12. The optical imaging system according to claim 1, characterized in that, The plurality of isolators also includes a fourth auxiliary isolator that is positioned on the image side of the fourth isolator and in contact with the image side surface of the fourth isolator. The maximum axial thickness CP4 of the fourth isolator, the maximum axial thickness CP4b of the fourth auxiliary isolator, and the air gap T45 between the fourth lens and the fifth lens on the optical axis satisfy the following condition: 3.45≤(CP4+CP4b) / T45≤5.

79.

13. The optical imaging system according to claim 1, characterized in that, The inner diameter d3s of the object side of the third isolator and the center thickness CT3 of the third lens on the optical axis satisfy the following condition: 2.51≤d3s / CT3≤4.

09.

14. The optical imaging system according to claim 1, characterized in that, The inner diameter of the object side surface of the third isolator is greater than the inner diameter of the object side surface of the second isolator. The maximum axial thickness CP2 of the second isolator, the center thickness CT3 of the third lens on the optical axis, the maximum axial thickness CP3 of the third isolator, and the distance EP23 between the image side surface of the second isolator and the object side surface of the third isolator on the optical axis satisfy the following: 1.22≤(CP2+CT3+CP3) / EP23≤2.

29.

15. The optical imaging system according to claim 1, characterized in that, The radius of curvature R4 of the image side of the second lens and the inner diameter d2s of the object side of the second isolator satisfy the following condition: 2.10≤R4 / d2s≤5.

11.

16. The optical imaging system according to any one of claims 1 to 15, characterized in that, The inner diameter of the object-side end face of the lens barrel is larger than the inner diameter of the image-side end face of the lens barrel, and the outer diameter of the image-side side of the first isolation member, the second isolation member, the third isolation member, and the fourth isolation member gradually decreases.

17. The optical imaging system according to any one of claims 1 to 15, characterized in that, The air gap T12 between the first lens and the second lens on the optical axis, the maximum axial thickness CP2 of the second isolator, and the air gap T23 between the second lens and the third lens on the optical axis satisfy the following: 2.72≤T12 / (CP2+T23)≤3.48.

Images