Optical imaging system

Abstract

The application provides an optical imaging system, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and satisfying the following conditions: 0.5 < f / EPD-TTL / ImgH < 1.5, wherein f is an effective focal length of the optical imaging system, EPD is an entrance pupil diameter of the optical imaging system, TTL is an on-axis distance from an object side of the first lens to an imaging surface of the optical imaging system, and ImgH is a half of a diagonal length of an effective pixel area on the imaging surface; 0.5 < CT1 / T12 < 5.0, wherein CT1 is a central thickness of the first lens on an optical axis, and T12 is a distance between the first lens and the second lens on the optical axis; and 1.0 < TTL / ImgH < 1.9, wherein TTL is the on-axis distance from the object side of the first lens to the imaging surface, and ImgH is the half of the diagonal length of the effective pixel area on the imaging surface. The application solves the problem of large volume of the optical imaging system in the prior art.

Description

[0001] This application is a divisional application of the invention patent filed on May 10, 2022, with application number 2022105322580 and invention title "Optical Imaging System". Technical Field

[0002] This invention relates to the field of optical imaging equipment technology, and more specifically, to an optical imaging system. Background Technology

[0003] With the rapid upgrading of smart electronic devices such as mobile phones, computers, and tablets, these products on the market are all developing towards full-screen and ultra-thin designs, and the function of front-facing cameras is indispensable. Currently, almost every laptop on the market has a front-facing camera installed. However, this once "essential" device is slowly being forgotten by laptop users. Unsatisfactory image quality and insufficient field of view are long-standing problems with laptop cameras. This invention proposes a small-head, wide-angle lens that, while ensuring excellent image quality, allows for a smaller and more aesthetically pleasing front end of the camera. It also facilitates obtaining a wider field of view of the subject during actual shooting, providing a better user experience. Furthermore, it is specifically designed for short-distance object distances, taking into account the laptop's usage environment.

[0004] In other words, existing optical imaging systems suffer from problems such as large size, inability to meet the market demand for narrow bezels, small field of view, inability to obtain a larger field of view of the subject, and poor image quality when the object distance is short. Summary of the Invention

[0005] The main objective of this invention is to provide an optical imaging system to solve the problem of large size in existing optical imaging systems.

[0006] To achieve the above objectives, according to one aspect of the present invention, an optical imaging system is provided, comprising: a first lens having positive optical power, wherein the object-side surface of the first lens is convex and the image-side surface of the first lens is concave; a second lens having optical power; a third lens having optical power, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave; a fourth lens having positive optical power, wherein the object-side surface of the fourth lens is concave and the image-side surface of the fourth lens is convex; and a fifth lens having negative optical power; wherein the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the axial distance TTL from the object-side surface of the first lens to the imaging surface of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following: 0.5 < f / EPD - TTL / ImgH < 1.5; and the center thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first lens and the second lens on the optical axis satisfy the following: 0.5 <CT1 / T12<5.0。

[0007] Furthermore, the maximum field of view (FOV) of the optical imaging system satisfies: FOV > 85°.

[0008] Furthermore, the edge thickness ET3 of the third lens, the edge thickness ET4 of the fourth lens, the center thickness CT3 of the third lens on the optical axis of the optical imaging system, and the center thickness CT4 of the fourth lens on the optical axis satisfy the following condition: 3.0 < ET3 / CT3 + CT4 / ET4 < 5.0.

[0009] Furthermore, the axial distance TTL from the object side of the first lens to the imaging surface of the optical imaging system, the effective focal length f of the optical imaging system, and half of the maximum field of view (Semi-FOV) of the optical imaging system satisfy the following: 0 < TTL / f - Tan(Semi-FOV) < 1.0.

[0010] Furthermore, the effective focal length f of the optical imaging system, the radius of curvature R9 of the object side of the fifth lens, and the radius of curvature R10 of the image side of the fifth lens satisfy the following relationship: 1.5 < f / R10 - f / R9 < 5.0.

[0011] Furthermore, the effective focal length f5 of the fifth lens, the radius of curvature R9 of the object side of the fifth lens, and the radius of curvature R10 of the image side of the fifth lens satisfy the following condition: 1.5 < |f5 / R9| + |f5 / R10| < 7.0.

[0012] Furthermore, the effective focal length f4 of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy the following condition: -3.0 < f4 / R8 < -1.5.

[0013] Furthermore, the curvature radius R5 of the object side of the third lens, the curvature radius R6 of the image side of the third lens, the curvature radius R1 of the object side of the first lens, and the curvature radius R2 of the image side of the first lens satisfy the following condition: 2.5≤R5 / R6+R2 / R1≤5.5.

[0014] Furthermore, the axial distance SAG41 between the intersection of the object side of the fourth lens and the optical axis of the optical imaging system to the vertex of the effective radius of the object side of the fourth lens, and the axial distance SAG42 between the intersection of the image side of the fourth lens and the optical axis to the vertex of the effective radius of the image side of the fourth lens, satisfy the following condition: 2.0 < SAG42 / SAG41 < 5.0.

[0015] Furthermore, the radius of curvature R9 of the object side of the fifth lens and the effective focal length f5 of the fifth lens satisfy the following condition: -1.5 < R9 / f5 < 2.0.

[0016] Furthermore, the effective focal length f2 of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy the following condition: -2.5 < f2 / R4 < 14.

[0017] Furthermore, the center thickness CT2 of the second lens and the distance T23 between the second and third lenses on the optical axis of the optical imaging system satisfy the following condition: 0.1 < T23 / CT2 < 1.7.

[0018] Furthermore, the effective focal length f4 of the fourth lens and the radius of curvature R6 of the image side surface of the third lens satisfy the following condition: 0.15 < f4 / R6 < 1.0.

[0019] Furthermore, the center thickness CT1 of the first lens and the center thickness CT4 of the fourth lens satisfy the following condition: 0.1 < CT1 / CT4 < 0.8.

[0020] According to another aspect of the present invention, an optical imaging system is provided, comprising: a first lens with a positive optical power, the object side of the first lens is convex, and the image side of the first lens is concave; a second lens with an optical power; a third lens with an optical power, the object side of the third lens is convex, and the image side of the third lens is concave; a fourth lens with a positive optical power, the object side of the fourth lens is concave, and the image side of the fourth lens is convex; a fifth lens with a negative optical power; wherein, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the on-axis distance TTL from the object side of the first lens to the imaging surface of the optical imaging system, and half of the diagonal length ImgH of the effective pixel region on the imaging surface satisfy: 0.5 < f / EPD - TTL / ImgH < 1.5; the central thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first lens and the second lens on the optical axis satisfy: 0.5 < CT1 / T12 < 5.0; the on-axis distance TTL from the object side of the first lens to the imaging surface of the optical imaging system and half of the diagonal length ImgH of the effective pixel region on the imaging surface satisfy: 1.0 < TTL / ImgH < 1.9.

[0021] Further, the maximum field of view FOV of the optical imaging system satisfies: FOV > 85°.

[0022] Further, the edge thickness ET3 of the third lens, the edge thickness ET4 of the fourth lens, the central thickness CT3 of the third lens on the optical axis of the optical imaging system and the central thickness CT4 of the fourth lens on the optical axis satisfy: 3.0 < ET3 / CT3 + CT4 / ET4 < 5.0.

[0023] Further, the on-axis distance TTL from the object side of the first lens to the imaging surface of the optical imaging system, the effective focal length f of the optical imaging system and half of the maximum field of view Semi-FOV of the optical imaging system satisfy: 0 < TTL / f - Tan(Semi-FOV) < 1.0.

[0024] Further, the effective focal length f of the optical imaging system, the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 1.5 < f / R10 - f / R9 < 5.0.

[0025] Further, the effective focal length f5 of the fifth lens, the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: 1.5 < |f5 / R9| + |f5 / R10| < 7.0.

[0026] Further, the effective focal length f4 of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: -3.0 < f4 / R8 < -1.5.

[0027] Furthermore, the curvature radius R5 of the object side of the third lens, the curvature radius R6 of the image side of the third lens, the curvature radius R1 of the object side of the first lens, and the curvature radius R2 of the image side of the first lens satisfy the following condition: 2.5≤R5 / R6+R2 / R1≤5.5.

[0028] Furthermore, the axial distance SAG41 between the intersection of the object side of the fourth lens and the optical axis of the optical imaging system to the vertex of the effective radius of the object side of the fourth lens, and the axial distance SAG42 between the intersection of the image side of the fourth lens and the optical axis to the vertex of the effective radius of the image side of the fourth lens, satisfy the following condition: 2.0 < SAG42 / SAG41 < 5.0.

[0029] Furthermore, the radius of curvature R9 of the object side of the fifth lens and the effective focal length f5 of the fifth lens satisfy the following condition: -1.5 < R9 / f5 < 2.0.

[0030] Furthermore, the effective focal length f2 of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy the following condition: -2.5 < f2 / R4 < 14.

[0031] Furthermore, the center thickness CT2 of the second lens and the distance T23 between the second and third lenses on the optical axis of the optical imaging system satisfy the following condition: 0.1 < T23 / CT2 < 1.7.

[0032] Furthermore, the effective focal length f4 of the fourth lens and the radius of curvature R6 of the image side surface of the third lens satisfy the following condition: 0.15 < f4 / R6 < 1.0.

[0033] Furthermore, the center thickness CT1 of the first lens and the center thickness CT4 of the fourth lens satisfy the following condition: 0.1 < CT1 / CT4 < 0.8.

[0034] Applying the technical solution of the present invention, the optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has a positive 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 an optical power; the third lens has an 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 a positive optical power, the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex; the fifth lens has a negative optical power; wherein, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system, and half of the diagonal length ImgH of the effective pixel region on the imaging surface satisfy: 0.5 < f / EPD - TTL / ImgH < 1.5; the central thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first lens and the second lens on the optical axis satisfy: 0.5 < CT1 / T12 < 5.0; the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system and half of the diagonal length ImgH of the effective pixel region on the imaging surface satisfy: 1.0 < TTL / ImgH < 1.9.

[0035] Based on a design premise of a 400mm object distance, the first lens is configured with positive optical power, a convex object-side surface, and a concave image-side surface. This design converges the light rays incident on the optical imaging system, allowing them to smoothly enter the rear, reducing the aperture and overall length of the system, thus facilitating miniaturization. The second lens is adapted to the first and second lenses to reduce light refraction and ensure a smooth light transition. The third lens, with its convex object-side surface, converges the light rays from the second lens before diverging them through its image-side surface, reducing aberrations and ensuring image quality. The fourth lens converges the light rays exiting the third lens, allowing them to smoothly and stably enter the fifth lens. This balances spherical and chromatic aberrations caused by the lenses, and the light rays, after diverging through the fifth lens, enter the image plane, ensuring image quality while also contributing to miniaturization and clear imaging even at short macro distances. By limiting f / EPD-TTL / ImgH to a reasonable range, constraining f / EPD, TTL, and ImgH together, the design of an optical imaging system needs to consider the relationship between these three factors. This ensures that the image height and total length of the optical imaging system are within a reasonable range while maintaining sufficient light transmission, avoiding problems such as insufficient light energy acquisition due to excessively small EPD, and low diffraction limit leading to poor image quality. Limiting CT1 / T12 to a reasonable range, and thus the distance between the first and second lenses, helps control the refraction angle of light between the first and second lenses, ensuring the image quality of the optical imaging system. Limiting TTL / ImgH to a reasonable range, while ensuring an appropriate image height, facilitates the miniaturization of the optical imaging lens. Attached Figure Description

[0036] 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:

[0037] Figure 1 A schematic diagram of the structure of an optical imaging system according to Example 1 of the present invention is shown;

[0038] Figures 2 to 5 It shows Figure 1 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system;

[0039] Figure 6 A schematic diagram of the optical imaging system of Example 2 of the present invention is shown;

[0040] Figures 7 to 10 It shows Figure 6 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system;

[0041] Figure 11 A schematic diagram of the optical imaging system of Example 3 of the present invention is shown;

[0042] Figures 12 to 15 It shows Figure 11 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system;

[0043] Figure 16 A schematic diagram of the optical imaging system of Example 4 of the present invention is shown;

[0044] Figures 17 to 20 It shows Figure 16 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system;

[0045] Figure 21 A schematic diagram of the optical imaging system of Example 5 of the present invention is shown;

[0046] Figures 22 to 25 It shows Figure 21 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system;

[0047] Figure 26 A schematic diagram of the optical imaging system of Example Six of the present invention is shown;

[0048] Figures 27 to 30 It shows Figure 26 On-axis chromatic aberration curves, astigmatism curves, distortion curves, and magnification chromatic aberration curves of a medium optical imaging system.

[0049] The above figures include the following reference numerals:

[0050] E1, First lens; S1, Object-side surface of the first lens; S2, Image-side surface of the first lens; STO, Aperture stop; E2, Second lens; S3, Object-side surface of the second lens; S4, Image-side surface of the second lens; E3, Third lens; S5, Object-side surface of the third lens; S6, Image-side surface of the third lens; E4, Fourth lens; S7, Object-side surface of the fourth lens; S8, Image-side surface of the fourth lens; E5, Fifth lens; S9, Object-side surface of the fifth lens; S10, Image-side surface of the fifth lens; E6, Filter; S11, Object-side surface of the filter; S12, Image-side surface of the filter; S13, Imaging plane. Detailed Implementation

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] In this paper, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of that convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of that concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The determination of the surface shape in the paraxial region can be based on the judgment method commonly used by those knowledgeable in the field, using the R value (R refers to the radius of curvature of the paraxial region, usually the R value in the lens database of optical software) to determine convexity or concavity. For the object side, when the R value is positive, it is determined to be convex, and when the R value is negative, it is determined to be concave; for the image side, when the R value is positive, it is determined to be concave, and when the R value is negative, it is determined to be convex.

[0057] To address the issue of large size in existing optical imaging systems, this invention provides an optical imaging system.

[0058] Example 1

[0059] like Figures 1 to 30As shown, the optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has positive optical power, its object-side surface is convex, and its image-side surface is concave. The second lens has optical power; the third lens has optical power, its object-side surface is convex, and its image-side surface is concave; the fourth lens has positive optical power, its object-side surface is concave, and its image-side surface is convex; the fifth lens has negative optical power. The effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the axial distance TTL from the object-side surface of the first lens to the imaging plane of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging plane satisfy the following condition: 0.5 < f / EPD - TTL / ImgH < 1.5. The center thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first and second lenses on the optical axis satisfy the following condition: 0.5 <CT1 / T12<5.0。

[0060] Based on a design premise of a 400mm object distance, the first lens is configured with positive optical power, a convex object-side surface, and a concave image-side surface. This design converges the light rays incident on the optical imaging system, allowing them to smoothly enter the rear, reducing the aperture and overall length of the system, thus facilitating miniaturization. The second lens is adapted to the first and second lenses to reduce light refraction and ensure a smooth light transition. The third lens, with its convex object-side surface, converges the light rays from the second lens before diverging them through its image-side surface, reducing aberrations and ensuring image quality. The fourth lens converges the light rays exiting the third lens, allowing them to smoothly and stably enter the fifth lens. This balances spherical and chromatic aberrations caused by the lenses, and the light rays, after diverging through the fifth lens, enter the image plane, ensuring image quality while also contributing to miniaturization and clear imaging even at short macro distances. By limiting f / EPD-TTL / ImgH to a reasonable range, and constraining f / EPD, TTL, and ImgH together, the design of an optical imaging system needs to consider the relationship between these three factors. This ensures that the image height and total length of the optical imaging system are within a reasonable range while maintaining sufficient light transmission, avoiding problems such as insufficient light energy acquisition due to an excessively small EPD, and a low diffraction limit leading to poor image quality. Similarly, limiting CT1 / T12 to a reasonable range, and thus the distance between the first and second lenses, facilitates control of the light refraction angle between the first and second lenses, ensuring the image quality of the optical imaging system.

[0061] Preferably, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the axial distance TTL from the object-side surface of the first lens to the imaging surface of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following: 0.75 < f / EPD - TTL / ImgH < 1.4. The center thickness CT1 of the first lens on the optical axis of the optical imaging system, and the distance T12 between the first and second lenses on the optical axis satisfy the following: 0.6 <CT1 / T12<4.8。

[0062] In this embodiment, the maximum field of view (FOV) of the optical imaging system satisfies: FOV > 85°. By limiting the maximum field of view of the optical imaging system to a range greater than 85°, the optical imaging system can provide a large field of view, which is beneficial for obtaining a larger field of view of the object being photographed during actual shooting. In other words, an optical imaging system with a large field of view can clearly capture a larger field of view. Preferably, 85° < FOV < 130°.

[0063] In this embodiment, the edge thickness ET3 of the third lens, the edge thickness ET4 of the fourth lens, the center thickness CT3 of the third lens on the optical axis of the optical imaging system, and the center thickness CT4 of the fourth lens on the optical axis satisfy the following condition: 3.0 < ET3 / CT3 + CT4 / ET4 < 5.0. By controlling ET3 / CT3 + CT4 / ET4 within a reasonable range, the refraction between the light rays at the third and fourth lenses can be reduced, better balancing the distortion and field curvature of the optical imaging system. Simultaneously, it ensures that the third and fourth lenses are not easily deformed during assembly, guaranteeing the stability of the field curvature. This setting also allows for greater flexibility in process adjustments, avoiding the risk of stray light due to appearance problems with these lenses, effectively ensuring the imaging quality of the optical imaging system. Preferably, 3.2 < ET3 / CT3 + CT4 / ET4 < 4.9.

[0064] In this embodiment, the axial distance TTL from the object side of the first lens to the imaging plane of the optical imaging system, the effective focal length f of the optical imaging system, and half of the maximum field of view (Semi-FOV) of the optical imaging system satisfy the following condition: 0 < TTL / f - Tan(Semi-FOV) < 1.0. By limiting TTL / f - Tan(Semi-FOV) within a reasonable range, TTL, f, and FOV are constrained together. This ensures that the optical imaging system has a sufficiently large focal length and an appropriate field of view while maintaining a small overall length, which is beneficial for miniaturization. Simultaneously, limiting the focal length and field of view within a reasonable range ensures the imaging effect of the optical imaging system on the scene. Preferably, 0.1 < TTL / f - Tan(Semi-FOV) < 0.77.

[0065] In this embodiment, the effective focal length f of the optical imaging system, the radius of curvature R9 of the object-side surface of the fifth lens, and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.5 < f / R10 - f / R9 < 5.0. By limiting f / R10 - f / R9 to a reasonable range, the sensitivity problem of the fifth lens caused by excessive focal length concentration can be effectively avoided. Simultaneously, controlling the radii of curvature of the object-side and image-side surfaces of the fifth lens within a reasonable range ensures that the tolerance requirements are more in line with current manufacturing capabilities. Combined with the fifth lens, this effectively balances spherical aberration, coma, and astigmatism in the optical imaging system, ensuring the imaging quality of the optical imaging system. Preferably, 1.6 < f / R10 - f / R9 < 4.8.

[0066] In this embodiment, the effective focal length f5 of the fifth lens, the radius of curvature R9 of the object-side surface of the fifth lens, and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.5 < |f5 / R9| + |f5 / R10| < 7.0. By controlling |f5 / R9| + |f5 / R10| within a reasonable range, the optical power of the fifth lens is limited to a reasonable range, avoiding excessive concentration of optical power on the fifth lens and avoiding the sensitivity problem of the fifth lens. At the same time, controlling the radius of curvature of the object-side and image-side surfaces of the fifth lens within a reasonable range ensures that the tolerance requirements are more in line with the current process capability level. Combined with the fifth lens, it effectively balances spherical aberration, coma, and astigmatism of the optical imaging system, ensuring the imaging quality of the optical imaging system. Preferably, 1.6 < |f5 / R9| + |f5 / R10| < 6.8.

[0067] In this embodiment, the effective focal length f4 of the fourth lens and the radius of curvature R8 of the image-side surface of the fourth lens satisfy the following condition: -3.0 < f4 / R8 < -1.5. By limiting f4 / R8 to a reasonable range, the radius of curvature of the image-side surface of the fourth lens is also limited to a reasonable range, reducing the refraction of light in the fourth lens and thus reducing its sensitivity. Furthermore, it effectively avoids a series of processing problems caused by poor manufacturability of the fourth lens. In addition, it also reduces spherical aberration generated by the fourth lens. Preferably, -2.9 < f4 / R8 < -1.7.

[0068] In this embodiment, the curvature radius R5 of the object-side surface of the third lens, the curvature radius R6 of the image-side surface of the third lens, the curvature radius R1 of the object-side surface of the first lens, and the curvature radius R2 of the image-side surface of the first lens satisfy the following condition: 2.5 ≤ R5 / R6 + R2 / R1 ≤ 5.5. By limiting R5 / R6 + R2 / R1 to a reasonable range, processing difficulties caused by excessive tilt angles are avoided. Simultaneously, constraining R1, R2, R5, and R6 within a reasonable range ensures that the dimensions of the first and third lenses are within a reasonable range, avoiding excessive size differences between them. This also reduces the sensitivity of the first three lenses, ensuring better convergence of external light and obtaining a larger aperture. Preferably, 2.5 ≤ R5 / R6 + R2 / R1 ≤ 5.3.

[0069] In this embodiment, the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis of the optical imaging system to the vertex of the effective radius of the object-side surface of the fourth lens, and the axial distance SAG42 between the intersection of the image-side surface of the fourth lens and the optical axis to the vertex of the effective radius of the image-side surface of the fourth lens, satisfy the following condition: 2.0 < SAG42 / SAG41 < 5.0. By limiting SAG42 / SAG41 to a reasonable range, the manufacturability of the fourth lens is ensured, the difficulty of the fourth lens manufacturing process is reduced, and the CRA can be better matched with the chip. Preferably, 2.2 < SAG42 / SAG41 < 5.0.

[0070] In this embodiment, the radius of curvature R9 of the object-side surface of the fifth lens and the effective focal length f5 of the fifth lens satisfy the condition: -1.5 < R9 / f5 < 2.0. By limiting R9 / f5 to a reasonable range, the shape and manufacturability of the fifth lens can be guaranteed. Simultaneously, limiting the focal length of the fifth lens to a reasonable range ensures the divergence of light rays, thereby ensuring that the optical imaging system obtains an appropriate image height and guarantees the imaging quality of the optical imaging system. Preferably, -1.4 < R9 / f5 < 1.5.

[0071] In this embodiment, the effective focal length f2 of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy the condition: -2.5 < f2 / R4 < 14. Limiting f2 / R4 within a reasonable range ensures the shape of the second lens and facilitates its fabrication. Simultaneously, limiting the focal length of the second lens within a reasonable range facilitates the rational allocation of optical power, ensuring the imaging quality of the optical imaging system. Preferably, -2.3 < f2 / R4 < 13.5.

[0072] In this embodiment, the central thickness CT2 of the second lens and the distance T23 between the second lens and the third lens on the optical axis of the optical imaging system satisfy: 0.1 < T23 / CT2 < 1.7. By restricting T23 / CT2 within a reasonable range and restricting the distance between the second lens and the third lens within a reasonable range, it is beneficial to control the deflection angle of light between the second lens and the third lens, ensuring the imaging quality of the optical imaging system and facilitating the miniaturization of the optical imaging system. Preferably, 0.12 < T23 / CT2 < 1.6.

[0073] In this embodiment, the effective focal length f4 of the fourth lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.15 < f4 / R6 < 1.0. By restricting f4 / R6 within a reasonable range, it is beneficial to control the deflection of light between the third lens and the fourth lens, facilitating the smooth transmission of light to ensure the imaging quality of the optical imaging system and facilitating the reasonable distribution of the optical power. Preferably, 0.18 < f4 / R6 < 0.9.

[0074] In this embodiment, the central thickness CT1 of the first lens and the central thickness CT4 of the fourth lens satisfy: 0.1 < CT1 / CT4 < 0.8. By restricting CT1 / CT4 within a reasonable range, it is beneficial to ensure the shapes of the first lens and the fourth lens and facilitate the processing of the first lens and the second lens. Preferably, 0.2 < CT1 / CT4 < 0.8.

[0075] Embodiment 2

[0076] As Figures 1 to 30 shown, the optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has a positive 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 an optical power; the third lens has an 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 a positive optical power, the object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex; the fifth lens has a negative optical power; wherein, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system, and half of the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: 0.5 < f / EPD - TTL / ImgH < 1.5; the central thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first lens and the second lens on the optical axis satisfy: 0.5 < CT1 / T12 < 5.0; the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the optical imaging system and half of the diagonal length ImgH of the effective pixel area on the imaging surface satisfy: 1.0 < TTL / ImgH < 1.9.

[0077] Based on a design premise of an object distance of 400mm, the first lens is configured with positive optical power, and its object-side surface is convex while its image-side surface is concave. This allows the light rays incident on the optical imaging system to converge smoothly, reducing the aperture and overall length of the system and facilitating miniaturization. The second lens is adapted to the first and second lenses to reduce the degree of light refraction and ensure a smooth light transition. The third lens, with its convex object-side surface, converges the light rays from the second lens before diverging them through its image-side surface, reducing aberrations and ensuring image quality. The fourth lens converges the light rays emitted from the third lens, allowing them to smoothly and stably enter the fifth lens. This balances spherical and chromatic aberrations caused by the lenses, and the light rays, after diverging through the fifth lens, enter the image plane, ensuring image quality while also contributing to the miniaturization of the optical imaging system. By limiting f / EPD-TTL / ImgH to a reasonable range, constraining f / EPD, TTL, and ImgH together, the design of an optical imaging system needs to consider the relationship between these three factors. This ensures that the image height and total length of the optical imaging system are within a reasonable range while maintaining sufficient light transmission, avoiding problems such as insufficient light energy acquisition due to excessively small EPD, and low diffraction limit leading to poor image quality. Limiting TTL / ImgH to a reasonable range, while ensuring an appropriate image height, facilitates the miniaturization of the optical imaging lens. Limiting CT1 / T12 to a reasonable range, and thus the distance between the first and second lenses, helps control the refraction angle of light between the first and second lenses, ensuring the image quality of the optical imaging system.

[0078] Preferably, the effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the axial distance TTL from the object-side surface of the first lens to the imaging surface of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following: 0.75 < f / EPD - TTL / ImgH < 1.4. The axial distance TTL from the object-side surface of the first lens to the imaging surface of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following: 1.1 < TTL / ImgH < 1.8. The center thickness CT1 of the first lens on the optical axis of the optical imaging system, and the distance T12 between the first and second lenses on the optical axis satisfy the following: 0.6. <CT1 / T12<4.8。

[0079] In this embodiment, the maximum field of view (FOV) of the optical imaging system satisfies: FOV > 85°. By limiting the maximum field of view of the optical imaging system to a range greater than 85°, the optical imaging system can provide a large field of view, which is beneficial for obtaining a larger field of view of the object being photographed during actual shooting. In other words, an optical imaging system with a large field of view can clearly capture a larger field of view. Preferably, 85° < FOV < 130°.

[0080] In this embodiment, the edge thickness ET3 of the third lens, the edge thickness ET4 of the fourth lens, the center thickness CT3 of the third lens on the optical axis of the optical imaging system, and the center thickness CT4 of the fourth lens on the optical axis satisfy the following condition: 3.0 < ET3 / CT3 + CT4 / ET4 < 5.0. By controlling ET3 / CT3 + CT4 / ET4 within a reasonable range, the refraction between the light rays at the third and fourth lenses can be reduced, better balancing the distortion and field curvature of the optical imaging system. Simultaneously, it ensures that the third and fourth lenses are not easily deformed during assembly, guaranteeing the stability of the field curvature. This setting also allows for greater flexibility in process adjustments, avoiding the risk of stray light due to appearance problems with these lenses, effectively ensuring the imaging quality of the optical imaging system. Preferably, 3.2 < ET3 / CT3 + CT4 / ET4 < 4.9.

[0081] In this embodiment, the axial distance TTL from the object side of the first lens to the imaging plane of the optical imaging system, the effective focal length f of the optical imaging system, and half of the maximum field of view (Semi-FOV) of the optical imaging system satisfy the following condition: 0 < TTL / f - Tan(Semi-FOV) < 1.0. By limiting TTL / f - Tan(Semi-FOV) within a reasonable range, TTL, f, and FOV are constrained together. This ensures that the optical imaging system has a sufficiently large focal length and an appropriate field of view while maintaining a small overall length, which is beneficial for miniaturization. Simultaneously, limiting the focal length and field of view within a reasonable range ensures the imaging effect of the optical imaging system on the scene. Preferably, 0.1 < TTL / f - Tan(Semi-FOV) < 0.77.

[0082] In this embodiment, the effective focal length f of the optical imaging system, the radius of curvature R9 of the object-side surface of the fifth lens, and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.5 < f / R10 - f / R9 < 5.0. By limiting f / R10 - f / R9 to a reasonable range, the sensitivity problem of the fifth lens caused by excessive focal length concentration can be effectively avoided. Simultaneously, controlling the radii of curvature of the object-side and image-side surfaces of the fifth lens within a reasonable range ensures that the tolerance requirements are more in line with current manufacturing capabilities. Combined with the fifth lens, this effectively balances spherical aberration, coma, and astigmatism in the optical imaging system, ensuring the imaging quality of the optical imaging system. Preferably, 1.6 < f / R10 - f / R9 < 4.8.

[0083] In this embodiment, the effective focal length f5 of the fifth lens, the radius of curvature R9 of the object-side surface of the fifth lens, and the radius of curvature R10 of the image-side surface of the fifth lens satisfy the following condition: 1.5 < |f5 / R9| + |f5 / R10| < 7.0. By controlling |f5 / R9| + |f5 / R10| within a reasonable range, the optical power of the fifth lens is limited to a reasonable range, avoiding excessive concentration of optical power on the fifth lens and avoiding the sensitivity problem of the fifth lens. At the same time, controlling the radius of curvature of the object-side and image-side surfaces of the fifth lens within a reasonable range ensures that the tolerance requirements are more in line with the current process capability level. Combined with the fifth lens, it effectively balances spherical aberration, coma, and astigmatism of the optical imaging system, ensuring the imaging quality of the optical imaging system. Preferably, 1.6 < |f5 / R9| + |f5 / R10| < 6.8.

[0084] In this embodiment, the effective focal length f4 of the fourth lens and the radius of curvature R8 of the image-side surface of the fourth lens satisfy the following condition: -3.0 < f4 / R8 < -1.5. By limiting f4 / R8 to a reasonable range, the radius of curvature of the image-side surface of the fourth lens is also limited to a reasonable range, reducing the refraction of light in the fourth lens and thus reducing its sensitivity. Furthermore, it effectively avoids a series of processing problems caused by poor manufacturability of the fourth lens. In addition, it also reduces spherical aberration generated by the fourth lens. Preferably, -2.9 < f4 / R8 < -1.7.

[0085] In this embodiment, the curvature radius R5 of the object-side surface of the third lens, the curvature radius R6 of the image-side surface of the third lens, the curvature radius R1 of the object-side surface of the first lens, and the curvature radius R2 of the image-side surface of the first lens satisfy the following condition: 2.5 ≤ R5 / R6 + R2 / R1 ≤ 5.5. By limiting R5 / R6 + R2 / R1 to a reasonable range, processing difficulties caused by excessive tilt angles are avoided. Simultaneously, constraining R1, R2, R5, and R6 within a reasonable range ensures that the dimensions of the first and third lenses are within a reasonable range, avoiding excessive size differences between them. This also reduces the sensitivity of the first three lenses, ensuring better convergence of external light and obtaining a larger aperture. Preferably, 2.5 ≤ R5 / R6 + R2 / R1 ≤ 5.3.

[0086] In this embodiment, the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis of the optical imaging system to the vertex of the effective radius of the object-side surface of the fourth lens, and the axial distance SAG42 between the intersection of the image-side surface of the fourth lens and the optical axis to the vertex of the effective radius of the image-side surface of the fourth lens, satisfy the following condition: 2.0 < SAG42 / SAG41 < 5.0. By limiting SAG42 / SAG41 to a reasonable range, the manufacturability of the fourth lens is ensured, difficulties in the manufacturing process of the fourth lens are avoided, and the CRA can be better matched with the chip. Preferably, 2.2 < SAG42 / SAG41 < 5.0.

[0087] In this embodiment, the radius of curvature R9 of the object-side surface of the fifth lens and the effective focal length f5 of the fifth lens satisfy the condition: -1.5 < R9 / f5 < 2.0. By limiting R9 / f5 to a reasonable range, the shape and manufacturability of the fifth lens can be guaranteed. Simultaneously, limiting the focal length of the fifth lens to a reasonable range ensures the divergence of light rays, thereby ensuring that the optical imaging system obtains an appropriate image height and guarantees the imaging quality of the optical imaging system. Preferably, -1.4 < R9 / f5 < 1.5.

[0088] In this embodiment, the effective focal length f2 of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy the condition: -2.5 < f2 / R4 < 14. Limiting f2 / R4 within a reasonable range ensures the shape of the second lens and facilitates its fabrication. Simultaneously, limiting the focal length of the second lens within a reasonable range facilitates the rational allocation of optical power, ensuring the imaging quality of the optical imaging system. Preferably, -2.3 < f2 / R4 < 13.5.

[0089] In this embodiment, the center thickness CT2 of the second lens and the distance T23 between the second and third lenses on the optical axis of the optical imaging system satisfy the following condition: 0.1 < T23 / CT2 < 1.7. By limiting T23 / CT2 within a reasonable range, the distance between the second and third lenses is also limited within a reasonable range, which helps to control the deflection angle of light between the second and third lenses, ensuring the imaging quality of the optical imaging system and also facilitating the miniaturization of the optical imaging system. Preferably, 0.12 < T23 / CT2 < 1.6.

[0090] In this embodiment, the effective focal length f4 of the fourth lens and the radius of curvature R6 of the image-side surface of the third lens satisfy the following condition: 0.15 < f4 / R6 < 1.0. Limiting f4 / R6 within a reasonable range helps control the refraction of light between the third and fourth lenses, promotes smooth light transmission, ensures the imaging quality of the optical imaging system, and facilitates a reasonable allocation of optical power. Preferably, 0.18 < f4 / R6 < 0.9.

[0091] In this embodiment, the center thickness CT1 of the first lens and the center thickness CT4 of the fourth lens satisfy the following condition: 0.1 < CT1 / CT4 < 0.8. Limiting CT1 / CT4 within a reasonable range helps to ensure the shape of the first and fourth lenses and facilitates the processing of the first and second lenses. Preferably, 0.2 < CT1 / CT4 < 0.8.

[0092] Optionally, the optical imaging system described above may also include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0093] The optical imaging system in this application can employ multiple lenses, such as the five lenses mentioned above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis distance between each lens, the imaging quality of the optical imaging system can be effectively increased, the sensitivity of the optical imaging system can be reduced, and the manufacturability of the optical imaging system can be improved, making the optical imaging system more conducive to production and processing and suitable for portable electronic devices such as smartphones.

[0094] 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 image formation can be eliminated as much as possible, thereby improving image quality.

[0095] However, those skilled in the art will understand that the number of lenses constituting the optical imaging system can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although five lenses have been described as an example in the embodiments, the optical imaging system is not limited to including five lenses. If necessary, the optical imaging system may also include other numbers of lenses.

[0096] 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.

[0097] It should be noted that any of the examples one through six below are applicable to all embodiments of this application.

[0098] Example 1

[0099] like Figures 1 to 5 As shown, an optical imaging system of Example 1 of this application is described. Figure 1 A schematic diagram of the optical imaging system in Example 1 is shown.

[0100] like Figure 1 As shown, the optical imaging system includes, in sequence from the object side to the image side, a first lens E1, an aperture stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0101] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive optical power, its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens E3 has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged onto the imaging surface S13.

[0102] In this example, the image height (ImgH) of the optical imaging system is 2.34 mm. The total length (TTL) of the optical imaging system is 3.52 mm.

[0103] Table 1 shows the basic structural parameters of the optical imaging system in Example 1, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0104]

[0105] Table 1

[0106] In Example 1, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the fifth lens E5, are aspherical. The surface shape of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0107]

[0108] 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 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 that can be used for the aspherical mirrors S1-S10 in Example 1.

[0109]

[0110]

[0111] Table 2

[0112] Figure 2 The on-axis chromatic aberration curve of the optical imaging system of Example 1 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 3 The astigmatism curves of the optical imaging system in Example 1 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 4 The distortion curves of the optical imaging system in Example 1 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 5 The magnification chromatic aberration curve of the optical imaging system in Example 1 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0113] according to Figures 2 to 5 As can be seen, the optical imaging system given in Example 1 can achieve good imaging quality.

[0114] Example 2

[0115] like Figures 6 to 10 As shown, an optical imaging system of Example 2 of this application is described. Figure 6 A schematic diagram of the optical imaging system in Example 2 is shown.

[0116] like Figure 6 As shown, the optical imaging system includes, in sequence from the object side to the image side, a first lens E1, an aperture stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0117] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is convex. The third lens E3 has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged onto the imaging surface S13.

[0118] In this example, the image height (ImgH) of the optical imaging system is 2.30 mm. The total length (TTL) of the optical imaging system is 3.42 mm.

[0119] Table 3 shows the basic structural parameters of the optical imaging system in Example 2, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0120]

[0121]

[0122] Table 3

[0123] Table 4 shows the higher-order coefficients that can be used for each aspherical mirror in Example 2, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0124]

[0125] Table 4

[0126] Figure 7 The on-axis chromatic aberration curve of the optical imaging system in Example 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the optical imaging system. Figure 8 The astigmatism curves of the optical imaging system in Example 2 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 9 The distortion curves of the optical imaging system in Example 2 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 10 The magnification chromatic aberration curve of the optical imaging system in Example 2 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0127] according to Figures 7 to 10As can be seen, the optical imaging system given in Example 2 can achieve good imaging quality.

[0128] Example 3

[0129] like Figures 11 to 15 As shown, an optical imaging system of Example 3 of this application is described. Figure 11 A schematic diagram of the optical imaging system in Example 3 is shown.

[0130] like Figure 11 As shown, the optical imaging system includes, in sequence from the object side to the image side, a first lens E1, an aperture stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0131] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is convex. The third lens E3 has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged onto the imaging surface S13.

[0132] In this example, the image height (ImgH) of the optical imaging system is 2.30 mm. The total length (TTL) of the optical imaging system is 3.41 mm.

[0133] Table 5 shows the basic structural parameters of the optical imaging system in Example 3, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0134]

[0135] Table 5

[0136] Table 6 shows the higher-order coefficients that can be used for each aspherical mirror in Example 3, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0137]

[0138] Table 6

[0139] Figure 12The on-axis chromatic aberration curve of the optical imaging system in Example 3 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 13 The astigmatism curves of the optical imaging system in Example 3 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 14 The distortion curves of the optical imaging system in Example 3 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 15 The magnification chromatic aberration curve of the optical imaging system in Example 3 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0140] according to Figures 12 to 15 As can be seen, the optical imaging system given in Example 3 can achieve good imaging quality.

[0141] Example 4

[0142] like Figures 16 to 20 As shown, an optical imaging system of Example 4 of this application is described. Figure 16 A schematic diagram of the optical imaging system in Example 4 is shown.

[0143] like Figure 16 As shown, the optical imaging system includes, in sequence from the object side to the image side, a first lens E1, an aperture stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0144] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has positive optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged on the imaging surface S13.

[0145] In this example, the image height (ImgH) of the optical imaging system is 2.88 mm. The total length (TTL) of the optical imaging system is 3.66 mm.

[0146] Table 7 shows the basic structural parameters of the optical imaging system in Example 4, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0147]

[0148] Table 7

[0149] Table 8 shows the higher-order coefficients that can be used for each aspherical mirror in Example 4, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0150]

[0151]

[0152] Table 8

[0153] Figure 17 The on-axis chromatic aberration curve of the optical imaging system in Example 4 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 18 The astigmatism curves of the optical imaging system in Example 4 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 19 The distortion curves of the optical imaging system in Example 4 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 20 The magnification chromatic aberration curve of the optical imaging system in Example 4 is shown, which represents the deviation of light at different image heights on the imaging surface after passing through the optical imaging system.

[0154] according to Figures 17 to 20 As can be seen, the optical imaging system given in Example 4 can achieve good imaging quality.

[0155] Example 5

[0156] like Figures 21 to 25 As shown, an optical imaging system of Example 5 of this application is described. Figure 21 A schematic diagram of the optical imaging system in Example 5 is shown.

[0157] like Figure 21 As shown, the optical imaging system includes, from the object side to the image side, an aperture stop STO, a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0158] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has negative optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is concave, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged onto the imaging surface S13.

[0159] In this example, the image height (ImgH) of the optical imaging system is 3.20 mm. The total length (TTL) of the optical imaging system is 3.69 mm.

[0160] Table 9 shows the basic structural parameters of the optical imaging system in Example 5, where the units for radius of curvature, thickness / distance, and focal length are millimeters (mm).

[0161]

[0162]

[0163] Table 9

[0164] Table 10 shows the higher-order coefficients that can be used for each aspherical mirror in Example 5, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0165]

[0166] Table 10

[0167] Figure 22 The on-axis chromatic aberration curve of the optical imaging system in Example 5 is shown, which represents the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 23 The astigmatism curves of the optical imaging system in Example 5 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 24 The distortion curves of the optical imaging system in Example 5 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 25 The magnification chromatic aberration curve of the optical imaging system in Example 5 is shown, which represents the deviation of light at different image heights on the imaging plane after passing through the optical imaging system.

[0168] according to Figures 22 to 25 As can be seen, the optical imaging system given in Example 5 can achieve good imaging quality.

[0169] Example 6

[0170] like Figures 26 to 30 As shown, an optical imaging system of Example Six of this application is described. Figure 26 A schematic diagram of the optical imaging system in Example 6 is shown.

[0171] like Figure 26 As shown, the optical imaging system includes, in sequence from the object side to the image side, a first lens E1, an aperture stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

[0172] The first lens E1 has positive optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens E2 has positive optical power, its object-side surface S3 is convex, and its image-side surface S4 is concave. The third lens E3 has negative optical power, its object-side surface S5 is convex, and its image-side surface S6 is concave. The fourth lens E4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens E5 has negative optical power, its object-side surface S9 is convex, and its image-side surface S10 is concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through surfaces S1 to S12 and is finally imaged on the imaging surface S13.

[0173] In this example, the image height (ImgH) of the optical imaging system is 2.05 mm. The total length (TTL) of the optical imaging system is 3.49 mm.

[0174] Table 11 shows the basic structural parameters of the optical imaging system of Example 6, where the units for radius of curvature, thickness / distance, and focal length are all millimeters (mm).

[0175]

[0176] Table 11

[0177] Table 12 shows the higher-order coefficients that can be used for each aspherical mirror in Example 6, wherein each aspherical surface type can be defined by formula (1) given in Example 1 above.

[0178]

[0179]

[0180] Table 12

[0181] Figure 27The on-axis chromatic aberration curve of the optical imaging system in Example Six is ​​shown, which represents the deflection of the focal point after light of different wavelengths passes through the optical imaging system. Figure 28 The astigmatism curves of the optical imaging system in Example Six are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 29 The distortion curves of the optical imaging system in Example 6 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 30 The magnification chromatic aberration curve of the optical imaging system in Example 6 is shown, which represents the deviation of light at different image heights on the imaging plane after passing through the optical imaging system.

[0182] according to Figures 27 to 30 As can be seen, the optical imaging system given in Example 6 can achieve good imaging quality.

[0183] In summary, Examples 1 through 6 satisfy the relationships shown in Table 13.

[0184]

[0185]

[0186] Table 13

[0187] Table 14 shows the effective focal lengths f1 to f5 of each lens in the optical imaging systems of Examples 1 to 6.

[0188] Example parameters 1 2 3 4 5 6 f(mm) 2.04 1.88 1.71 2.36 3.14 1.80 f1(mm) 8.82 34.63 88.25 5.03 2.91 9.03 f2 (mm) 3.98 2.52 2.33 124.13 -16.43 11.26 f3 (mm) -22.55 -11.36 -7.60 22.74 -30.73 -54.47 f4 (mm) 1.52 1.32 1.25 1.14 2.33 1.12 f5 (mm) -2.19 -1.95 -1.81 -1.19 -1.79 -1.59 TTL(mm) 3.52 3.42 3.41 3.66 3.69 3.49 ImgH(mm) 2.34 2.30 2.30 2.88 3.20 2.05 Semi-FOV (°) 49.9 54.8 61.7 50.9 44.1 50.2 SAG51 (mm) 2.04 1.88 1.71 2.36 3.14 1.80

[0189] Table 14

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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 by, include: A first lens with positive optical power, wherein the object side of the first lens is convex and the image side of the first lens is concave; A second lens with positive optical power; A third lens with negative optical power, wherein the object-side surface of the third lens is convex and the image-side surface of the third lens is concave; A fourth lens with positive optical power, wherein the object-side surface of the fourth lens is concave and the image-side surface of the fourth lens is convex; A fifth lens with negative optical power, wherein the object-side surface of the fifth lens is convex and the image-side surface of the fifth lens is concave; The effective focal length f of the optical imaging system, the entrance pupil diameter EPD of the optical imaging system, the axial distance TTL from the object side of the first lens to the imaging surface of the optical imaging system, and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following condition: 0.78≤f / EPD-TTL / ImgH≤1.

00. The center thickness CT1 of the first lens on the optical axis of the optical imaging system and the distance T12 between the first lens and the second lens on the optical axis satisfy the following: 1.93≤CT1 / T12≤3.14; The axial distance TTL from the object side of the first lens to the imaging surface of the optical imaging system and half the diagonal length ImgH of the effective pixel area on the imaging surface satisfy the following condition: 1.48≤TTL / ImgH≤1.70; The effective focal length f5 of the fifth lens, the radius of curvature R9 of the object side of the fifth lens, and the radius of curvature R10 of the image side of the fifth lens satisfy the following condition: 4.19≤|f5 / R9|+|f5 / R10|≤6.69; The center thickness CT1 of the first lens and the center thickness CT4 of the fourth lens satisfy the following condition: 0.34≤CT1 / CT4≤0.

47.

2. The optical imaging system of claim 1, wherein, The maximum field of view (FOV) of the optical imaging system satisfies: 99.90°≤FOV≤123.40°.

3. The optical imaging system of claim 1, wherein, The edge thickness ET3 of the third lens, the edge thickness ET4 of the fourth lens, the center thickness CT3 of the third lens on the optical axis of the optical imaging system, and the center thickness CT4 of the fourth lens on the optical axis satisfy the following condition: 3.49≤ET3 / CT3+CT4 / ET4≤4.

24.

4. The optical imaging system of claim 1, wherein, The on-axis distance TTL from the object side of the first lens to the imaging surface of the optical imaging system, the effective focal length f of the optical imaging system, and half of the maximum field of view (Semi-FOV) of the optical imaging system satisfy the following: 0.14≤TTL / f-Tan(Semi-FOV)≤0.

74.

5. The optical imaging system of claim 1, wherein, The effective focal length f of the optical imaging system, the radius of curvature R9 of the object side of the fifth lens, and the radius of curvature R10 of the image side of the fifth lens satisfy the following: 1.71 / 0.5997-1.71 / 1.5249≤f / R10-f / R9≤1.80 / 0.4402-1.80 / 0.9483.

6. The optical imaging system of claim 1, wherein, An on-axis distance SAG41 between an intersection of the object side surface of the fourth lens and an optical axis of the optical imaging system to an effective radius vertex of the object side surface of the fourth lens, and an on-axis distance SAG42 between an intersection of the image side surface of the fourth lens and the optical axis to an effective radius vertex of the image side surface of the fourth lens satisfy: 2.65≤SAG42 / SAG41≤4.

96.

7. The optical imaging system of claim 1, wherein, A curvature radius R9 of the object side surface of the fifth lens and an effective focal length f5 of the fifth lens satisfy: -0.84≤R9 / f5≤-0.

43.

8. The optical imaging system of claim 1, wherein, An effective focal length f2 of the second lens and a curvature radius R4 of the image side surface of the second lens satisfy: -1.98≤f2 / R4≤0.

41.

9. The optical imaging system of claim 1, wherein, A central thickness CT2 of the second lens and a distance T23 between the second lens and the third lens on the optical axis of the optical imaging system satisfy: 0.06 / 0.3598≤T23 / CT2≤0.06 / 0.3038.

10. The optical imaging system of claim 1, wherein, An effective focal length f4 of the fourth lens and a curvature radius R6 of the image side surface of the third lens satisfy: 1.25 / 3.4887≤f4 / R6≤1.52 / 1.

897.

11. The optical imaging system of claim 1, wherein, An effective focal length f4 of the fourth lens and a curvature radius R8 of an image side surface of the fourth lens satisfy: -2.77≤f4 / R8≤-2.

01.

12. The optical imaging system of claim 1, wherein, A curvature radius R5 of the object side surface of the third lens, a curvature radius R6 of the image side surface of the third lens, a curvature radius R1 of the object side surface of the first lens, and a curvature radius R2 of the image side surface of the first lens satisfy: 2.50≤R5 / R6+R2 / R1≤5.07.

Images