Optical imaging system

Abstract

This application discloses an optical imaging system, which includes, along the optical axis from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. The first lens has negative optical power; the second and third lenses have positive optical power; the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: R3 / R4>0; the radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: R5 / R6<0; the maximum semi-field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV>60.0°; and the effective focal length f of the optical imaging system and the entrance pupil diameter (EPD) of the optical imaging system satisfy: f / EPD<1.5.

Description

Technical Field

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

[0002] With the development of AR / VR gesture interaction, smartphones, smart wearable devices, drones, automobiles, and other fields, 3D depth sensing technology has gradually become a research hotspot in recent years. Among them, TOF (Time of Flight) technology, as one of the mainstream solutions, is widely used due to its advantages such as small measurement error and strong anti-interference ability.

[0003] Common TOF lenses still have some problems, such as a small field of view, low relative illumination, and large distortion. Therefore, designing an infrared TOF lens with wide-angle, low distortion, and high brightness is of great practical significance in order to meet market demands. Summary of the Invention

[0004] This application provides an optical imaging system comprising, along the optical axis from the object side to the image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; wherein the first lens has negative optical power; the second and third lenses have positive optical power; the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: R3 / R4>0; the radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: R5 / R6<0; the maximum semi-field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV>60.0°; and the effective focal length f of the optical imaging system and the entrance pupil diameter (EPD) of the optical imaging system satisfy: f / EPD<1.5.

[0005] In one embodiment, the effective focal length f of the optical imaging system and the effective focal length f1 of the first lens satisfy: f > 1.5 mm and -2.5 mm. <f1 / f<-1.5。

[0006] In one embodiment, the effective focal length f2 of the second lens, the radius of curvature R3 of the object-side surface of the second lens, and the radius of curvature R4 of the image-side surface of the second lens satisfy: -0.5 <f2 / (R3+R4)<-0.1。

[0007] In one embodiment, the central thickness CT3 of the third lens on the optical axis, the radius of curvature R5 of the object-side surface of the third lens, and the radius of curvature R6 of the image-side surface of the third lens satisfy: 0 <CT3 / (R5-R6)<0.5。

[0008] In one embodiment, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f of the optical imaging system satisfy: 1.5 < f2 / f < 2.5 and 1.5 < f3 / f < 2.5.

[0009] In one embodiment, the central thickness CT3 of the third lens on the optical axis and the central thickness CT4 of the fourth lens on the optical axis satisfy: CT3 > 1.0 mm > CT4.

[0010] In one embodiment, the central thickness CT2 of the second lens on the optical axis, the central thickness CT3 of the third lens on the optical axis, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy: 0.5 < CT2 / f2 + CT3 / f3 < 1.0.

[0011] In one embodiment, the entrance pupil diameter EPD of the optical imaging system, the maximum effective radius DT12 of the image side of the first lens, and the maximum effective radius DT21 of the object side of the second lens satisfy: 2.4 < EPD / DT12 + EPD / DT21 < 3.0.

[0012] In one embodiment, the maximum effective radius DT42 of the image side of the fourth lens, the maximum effective radius DT51 of the object side of the fifth lens, the radius of curvature R8 of the image side of the fourth lens, and the radius of curvature R9 of the object side of the fifth lens satisfy: DT51 / DT42 ≥ 1.0 and -2.6 < R8 / DT42 - R9 / DT51 < -1.6.

[0013] In one embodiment, the on-axis distance TOL from the object to the object side of the first lens satisfies: 0 mm < TOL < 500 mm.

[0014] In one embodiment, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the refractive index N2 of the second lens, the refractive index N3 of the third lens, and the combined focal length f23 of the second lens and the third lens satisfy: 6.1 < [f2 / (N2 - 1) + f3 / (N3 - 1)] / f23 < 6.6.

[0015] In one embodiment, the central thickness CT2 of the second lens on the optical axis, the central thickness CT3 of the third lens on the optical axis, the edge thickness ET2 of the second lens, the edge thickness ET3 of the third lens, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy: CT2 > ET2, CT3 > ET3, and 0.3 < (CT2 - ET2) / f2 + (CT3 - ET3) / f3 < 0.5.

[0016] In one embodiment, the air gap T45 between the fourth and fifth lenses on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0.3 < (T45 + CT5) / R9 < 0.6.

[0017] In one embodiment, the maximum effective radius DT11 of the object side of the first lens, the maximum effective radius DT52 of the image side of the fifth lens, and the effective focal length f of the optical imaging system satisfy: 0 < (DT11 - DT52) / f < 0.4.

[0018] In one embodiment, the axial distance SAG32 between the intersection of the image-side surface of the third lens and the optical axis and the vertex of the effective radius of the image-side surface of the third lens, the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis and the vertex of the effective radius of the object-side surface of the fourth lens, and the radius of curvature R6 of the image-side surface of the third lens and the radius of curvature R7 of the object-side surface of the fourth lens satisfy: 0.2 <SAG32 / R6+SAG41 / R7<1.0。

[0019] In one embodiment, the optical imaging system further includes an aperture stop disposed between the first lens and the second lens, wherein the axial distance SL from the aperture stop to the imaging plane of the optical imaging system and the axial distance SD from the aperture stop to the image-side surface of the fifth lens satisfy: 0.6 <SD / SL<1.1。

[0020] In one embodiment, any two adjacent lenses among the first to fifth lenses have an air gap on the optical axis, and the sum of the air gaps ∑AT satisfies the condition that the air gap T12 between the first and second lenses on the optical axis is 0.5. <T12 / ∑AT<1.0。

[0021] In one embodiment, the axial distance SAG12 between the intersection of the image-side surface of the first lens and the optical axis and the vertex of the effective radius of the image-side surface of the first lens, the axial distance SAG22 between the intersection of the image-side surface of the second lens and the optical axis and the vertex of the effective radius of the image-side surface of the second lens, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0.1 < (SAG12 + |SAG22|) / (CT1 + T12 + CT2) < 0.5.

[0022] In one implementation, the optical imaging system operates in the wavelength range of 800 nm to 1000 nm.

[0023] The optical imaging system of this application, through the appropriate combination of the number, shape, and power of lenses, can effectively reduce the total optical length of the optical imaging system while ensuring high imaging quality. The maximum semi-field of view (Semi-FOV) of the optical imaging system satisfies: Semi-FOV > 60.0°, which is beneficial for the lens to receive information over a larger field of view of the object, ensuring the system's large field of view characteristics; and the effective focal length f and entrance pupil diameter (EPD) of the optical imaging system satisfy: f / EPD < 1.5, which helps to improve the lens's ability to receive light source energy and increase image brightness. Attached Figure Description

[0024] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 A schematic diagram of the structure of an optical imaging system according to Embodiment 1 of this application is shown;

[0026] Figures 2A to 2C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 1 are shown respectively.

[0027] Figure 3 A schematic diagram of the structure of an optical imaging system according to Embodiment 2 of this application is shown;

[0028] Figures 4A to 4C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 2 are shown respectively.

[0029] Figure 5 A schematic diagram of the structure of an optical imaging system according to Embodiment 3 of this application is shown;

[0030] Figures 6A to 6C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 3 are shown respectively.

[0031] Figure 7 A schematic diagram of the structure of an optical imaging system according to Embodiment 4 of this application is shown;

[0032] Figures 8A to 8C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 4 are shown respectively.

[0033] Figure 9 A schematic diagram of the structure of an optical imaging system according to Embodiment 5 of this application is shown;

[0034] Figures 10A to 10C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 5 are shown respectively.

[0035] Figure 11 A schematic diagram of the structure of an optical imaging system according to Embodiment 6 of this application is shown;

[0036] Figures 12A to 12C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 6 are shown respectively.

[0037] Figure 13 A schematic diagram of the structure of an optical imaging system according to Embodiment 7 of this application is shown; and

[0038] Figures 14A to 14C The astigmatism curve, distortion curve, and relative illumination curve of the optical imaging system of Example 7 are shown respectively. Detailed Implementation

[0039] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] 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.

[0041] 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 strictly to scale.

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0043] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] The features, principles and other aspects of this application are described in detail below.

[0047] An optical imaging system according to an exemplary embodiment of this application may include five lenses with optical power, namely a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. These five lenses are arranged sequentially along the optical axis from the object side to the image side. Any two adjacent lenses among the first to fifth lenses may have a gap between them.

[0048] In an exemplary embodiment, the first lens may have a negative optical power; the second lens may have a positive optical power; the third lens may have a positive optical power; the fourth lens may have a positive or negative optical power; and the fifth lens may have a positive or negative optical power. By reasonably matching the number of lenses, surface shapes, and optical powers, the overall optical length of the optical imaging system can be effectively reduced, and a high imaging quality of the system can be ensured. Among them, the focal length value of the first lens is negative, mainly to collect light and ensure the wide-angle characteristic of the system; the focal length values of the second lens and the third lens are positive, mainly to correct various on-axis and off-axis aberrations of the system and improve imaging clarity. The curvature radius value of the object side surface of the second lens is less than zero, and the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: R3 / R4 > 0, which can effectively correct the spherical aberration and distortion of the system; the curvature radius value of the object side surface of the third lens is greater than zero, and the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: R5 / R6 < 0, which can effectively control the deflection of the system light and ensure the convergence of light on the image plane. The maximum semi-field angle Semi-FOV of the optical imaging system satisfies: Semi-FOV > 60.0°, which is beneficial for the lens to receive information within a larger field of view on the object side and ensure the large-field-angle characteristic of the system; and the effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: f / EPD < 1.5, which helps to improve the light energy reception ability of the lens and improve imaging brightness.

[0049] In an exemplary embodiment, the optical imaging system according to the exemplary embodiment of the present application further includes an aperture disposed between the first lens and the second lens.

[0050] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: f > 1.5 mm and -2.5 < f1 / f < -1. ., where f is the effective focal length of the optical imaging system and f1 is the effective focal length of the first lens. By controlling the effective focal length of the optical imaging system to be greater than 1.5, the field of view angle and imaging size of the system can be ensured; at the same time, satisfying -2.5 < f1 / f < -1.5 can effectively control the optical power borne by the first lens and reasonably distribute the deflection of light by each lens.

[0051] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: -0.5 < f2 / (R3 + R4) < -0.1, where f2 is the effective focal length of the second lens, R3 is the curvature radius of the object side surface of the second lens, and R4 is the curvature radius of the image side surface of the second lens. Satisfying -0.5 < f2 / (R3 + R4) < -0.1 is beneficial for ensuring the processing and shaping of the lens on the one hand and correcting the astigmatism of the system on the other hand.

[0052] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0 < CT3 / (R5 - R6) < 0.5, where CT3 is the central thickness of the third lens on the optical axis, R5 is the curvature radius of the object side surface of the third lens, and R6 is the curvature radius of the image side surface of the third lens. Satisfying 0 < CT3 / (R5 - R6) < 0.5 is beneficial to improving the processing and assembly yield of the third lens and correcting the distortion of the system.

[0053] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 1.5 < f2 / f < 2.5 and 1.5 < f3 / f < 2.5, where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f is the effective focal length of the optical imaging system. Satisfying 1.5 < f2 / f < 2.5 and 1.5 < f3 / f < 2.5 can reasonably distribute the optical power borne by the second lens and the third lens, and further correct the coma and field curvature of the system on the premise of ensuring smooth transition of light rays.

[0054] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: CT3 > 1.0 mm > CT4, where CT3 is the central thickness of the third lens on the optical axis, and CT4 is the central thickness of the fourth lens on the optical axis. Satisfying CT3 > 1.0 mm > CT4 can compress the optical size of the system as much as possible on the premise of ensuring the imaging quality of the system, and ensure the miniaturization characteristics of the system.

[0055] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.5 < CT2 / f2 + CT3 / f3 < 1.0, where CT2 is the central thickness of the second lens on the optical axis, CT3 is the central thickness of the third lens on the optical axis, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens. Satisfying 0.5 < CT2 / f2 + CT3 / f3 < 1.0 can, on the one hand, effectively control the thicknesses of the second lens and the third lens and ensure the assembly yield of the lens, and on the other hand, can effectively correct the field curvature and distortion of the system.

[0056] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 2.4 < EPD / DT12 + EPD / DT21 < 3.0, where EPD is the entrance pupil diameter of the optical imaging system, DT12 is the maximum effective radius of the image side surface of the first lens, and DT21 is the maximum effective radius of the object side surface of the second lens. Satisfying 2.4 < EPD / DT12 + EPD / DT21 < 3.0 can effectively control the apertures of the lenses before and after the aperture stop, reduce the step difference, and ensure the assembly feasibility of the lens.

[0057] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: DT51 / DT42 ≥ 1.0 and -2.6 < R8 / DT42 - R9 / DT51 < -1.6, where DT42 is the maximum effective radius of the image side of the fourth lens, DT51 is the maximum effective radius of the object side of the fifth lens, R8 is the radius of curvature of the image side of the fourth lens, and R9 is the radius of curvature of the object side of the fifth lens. Satisfying DT51 / DT42 ≥ 1.0 can effectively control the deflection of marginal rays and improve the marginal illuminance of the system; at the same time, satisfying -2.6 < R8 / DT42 - R9 / DT51 < -1.6 is beneficial to reducing the intensity of ghost images generated between the fourth lens and the fifth lens and improving the imaging quality.

[0058] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0 mm < TOL < 500 mm, where TOL is the on-axis distance from the object to be photographed to the object side of the first lens. Satisfying 0 mm < TOL < 500 mm is beneficial to ensuring the imaging quality of the system.

[0059] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 6.1 < [f2 / (N2 - 1) + f3 / (N3 - 1)] / f23 < 6.6, where f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, N2 is the refractive index of the second lens, N3 is the refractive index of the third lens, and f23 is the combined focal length of the second lens and the third lens. Satisfying 6.1 < [f2 / (N2 - 1) + f3 / (N3 - 1)] / f23 < 6.6 is beneficial to correcting the spherical aberration of the system and improving the processing yield of the second lens and the third lens.

[0060] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: CT2 > ET2, CT3 > ET3, and 0.3 < (CT2 - ET2) / f2 + (CT3 - ET3) / f3 < 0.5, where CT2 is the central thickness of the second lens on the optical axis, CT3 is the central thickness of the third lens on the optical axis, ET2 is the edge thickness of the second lens, ET3 is the edge thickness of the third lens, f2 is the effective focal length of the second lens, and f3 is the effective focal length of the third lens. By controlling CT2 > ET2 and CT3 > ET3, it can ensure that the lens has good processability; controlling 0.3 < (CT2 - ET2) / f2 + (CT3 - ET3) / f3 < 0.5 is beneficial to correcting the distortion of the system.

[0061] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.3 < (T45 + CT5) / R9 < 0.6, where T45 is the air gap between the fourth lens and the fifth lens on the optical axis, CT5 is the central thickness of the fifth lens on the optical axis, and R9 is the radius of curvature of the object side surface of the fifth lens. Satisfying 0.3 < (T45 + CT5) / R9 < 0.6 is beneficial to improving the assembly yield of the optical imaging system.

[0062] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0 < (DT11 - DT52) / f < 0.4, where DT11 is the maximum effective radius of the object side surface of the first lens, DT52 is the maximum effective radius of the image side surface of the fifth lens, and f is the effective focal length of the optical imaging system. Satisfying 0 < (DT11 - DT52) / f < 0.4 helps to reduce the volume of the optical imaging system.

[0063] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.2 < SAG32 / R6 + SAG41 / R7 < 1.0, where SAG32 is the axial distance between the intersection of the image side surface of the third lens and the optical axis and the vertex of the effective radius of the image side surface of the third lens, SAG41 is the axial distance between the intersection of the object side surface of the fourth lens and the optical axis and the vertex of the effective radius of the object side surface of the fourth lens, R6 is the radius of curvature of the image side surface of the third lens, and R7 is the radius of curvature of the object side surface of the fourth lens.Satisfying 0.2 < SAG32 / R6 + SAG41 / R7 < 1.0 is beneficial to reducing the ghost image generated between the third lens and the fourth lens.

[0064] In an exemplary embodiment, the optical imaging system further includes an aperture disposed between the first lens and the second lens. The optical imaging system according to the present application may satisfy: 0.6 < SD / SL < 1.1, where SL is the axial distance from the aperture to the imaging surface of the optical imaging system, and SD is the axial distance from the aperture to the image side surface of the fifth lens. More specifically, SD and SL further satisfy 0.6 < SD / SL < 0.85. Satisfying 0.6 < SD / SL < 1.1 can weaken the optical size of the optical imaging system as much as possible on the premise of ensuring the assembly feasibility of the optical imaging system.

[0065] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.5 < T12 / ∑AT < 1.0, where ∑AT is the sum of the air gaps between any two adjacent lenses from the first lens to the fifth lens on the optical axis, and T12 is the air gap between the first lens and the second lens on the optical axis. Satisfying 0.5 < T12 / ∑AT < 1.0 can ensure that the optical imaging system has the characteristic of a large field of view.

[0066] In an exemplary embodiment, the optical imaging system according to this application satisfies: 0.1 < (SAG12 + |SAG22|) / (CT1 + T12 + CT2) < 0.5, where SAG12 is the axial distance between the intersection of the image-side surface of the first lens and the optical axis and the vertex of the effective radius of the image-side surface of the first lens; SAG22 is the axial distance between the intersection of the image-side surface of the second lens and the optical axis and the vertex of the effective radius of the image-side surface of the second lens; CT1 is the center thickness of the first lens on the optical axis; CT2 is the center thickness of the second lens on the optical axis; and T12 is the air gap between the first lens and the second lens on the optical axis. Satisfying 0.1 < (SAG12 + |SAG22|) / (CT1 + T12 + CT2) < 0.5 is beneficial for improving the assembly yield of the optical imaging system and reducing its cost.

[0067] In an exemplary embodiment, the optical imaging system according to this application operates in the range of 800nm ​​to 1000nm.

[0068] In an exemplary embodiment, at least one of the mirror surfaces of each of the first to fifth lenses is an aspherical mirror surface. This application does not specifically limit the number of spherical and aspherical lenses; if image resolution is a primary concern, all lenses can be aspherical. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. A spherical lens, on the other hand, has a constant curvature from its center to its periphery. Aspherical lenses have better radius of curvature 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. Optionally, the object-side and image-side surfaces of each of the first to fifth lenses are aspherical mirror surfaces.

[0069] In an exemplary embodiment, the effective focal length f1 of the first lens can be, for example, in the range of -3.7 mm to -2.3 mm; the effective focal length f2 of the second lens can be, for example, in the range of 2.9 mm to 3.8 mm; the effective focal length f3 of the third lens can be, for example, in the range of 2.7 mm to 3.8 mm; the effective focal length f4 of the fourth lens can be, for example, in the range of -19.8 mm to 18.9 mm; and the effective focal length f5 of the fifth lens can be, for example, in the range of -10.7 mm to 57.3 mm. The effective focal length f of the optical imaging system can satisfy 1.5 mm ≤ f ≤ 1.6 mm. The distance TTL from the object side of the first lens to the imaging surface of the optical imaging system on the optical axis can satisfy 6.4 mm ≤ TTL < 8.0 mm. Half the diagonal length ImgH of the effective pixel area on the imaging surface of the optical imaging system can be, for example, in the range of 1.9 mm to 2.2 mm.

[0070] In an exemplary embodiment, the optical imaging system according to this application further includes a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0071] This application proposes an optical imaging lens with characteristics such as a large image area, high pixel count, miniaturization, and high image quality. The optical imaging lens according to the above embodiments of 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 spacing between lenses, incident light rays can be effectively converged, the overall optical length of the imaging lens can be reduced, and the manufacturability of the imaging lens can be improved, making the optical imaging lens more favorable for manufacturing. However, those skilled in the art should 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 are 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.

[0072] Specific embodiments of the optical imaging system applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0073] Example 1

[0074] The following is for reference Figures 1 to 2C An optical imaging system according to Embodiment 1 of this application is described. Figure 1 A schematic diagram of the structure of an optical imaging system according to Embodiment 1 of this application is shown.

[0075] 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.

[0076] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0077] In this example, the effective focal length f of the optical imaging system is 1.56 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 6.41 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 1.99 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.23, and the maximum semi-FOV of the optical imaging system is 76.7°.

[0078] Table 1 shows the basic parameters of the optical imaging system of Example 1, where the units for radius of curvature, thickness, and effective focal length are millimeters (mm).

[0079]

[0080]

[0081] Table 1

[0082] In Example 1, the object-side surface and image-side surface of any one of the first lens E1 to the fifth lens E5 are aspherical. The surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0083]

[0084] 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. Tables 2-1 and 2-2 below give the higher-order coefficients A4, A6, A8, A10 that can be used for each aspherical mirror S1-S10 in Example 1. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0085] Face number A4 A6 A8 A10 A12 A14 A16 S1 1.7084E-01 -9.2327E-02 8.0851E-03 8.6347E-02 -1.4345E-01 1.3418E-01 -8.4128E-02 S2 2.2937E-01 3.9723E-01 -2.6105E+00 -3.0783E+00 1.4597E+02 -1.0397E+03 4.1548E+03 S3 7.3168E-02 -1.6167E+00 1.6262E+01 -9.6457E+01 3.5109E+02 -7.9667E+02 1.1073E+03 S4 2.9631E-02 -5.5878E-02 -5.2278E-02 4.1345E-01 -8.8177E-01 1.0253E+00 -7.0956E-01 S5 4.4342E-02 -1.1462E-01 1.7594E-01 -1.9014E-01 1.4070E-01 -7.4026E-02 2.9166E-02 S6 -1.8995E-01 3.5713E-01 -3.7234E-01 1.1389E-01 3.0444E-01 -5.7372E-01 5.1930E-01 S7 1.5112E-01 1.5388E-01 -2.2783E-01 -1.5423E-01 8.5387E-01 -1.2818E+00 1.0926E+00 S8 2.7040E-01 -7.7732E-01 3.1296E+00 -9.0383E+00 1.8943E+01 -2.9440E+01 3.4245E+01 S9 6.6372E-02 -9.3465E-01 3.4841E+00 -9.7647E+00 2.1514E+01 -3.6578E+01 4.6728E+01 S10 1.1163E-01 -2.5587E-01 -2.4107E-01 2.6028E+00 -6.9347E+00 1.0598E+01 -1.0639E+01

[0086] Table 2-1

[0087]

[0088]

[0089] Table 2-2

[0090] Figure 2A 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 2B The distortion curves of the optical imaging system of Example 1 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 2C The relative illumination curves of the optical imaging system of Example 1 are shown, representing the relative illumination values ​​corresponding to different field of view angles. According to... Figures 2A to 2C It can be seen that the optical imaging system given in Example 1 can achieve good imaging quality.

[0091] Example 2

[0092] The following is for reference Figures 3 to 4C An optical imaging system according to Embodiment 2 of this application is described. In this embodiment and the following embodiments, for the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted. Figure 3 A schematic diagram of the structure of an optical imaging system according to Embodiment 2 of this application is shown.

[0093] like Figure 3 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.

[0094] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0095] In this example, the effective focal length f of the optical imaging system is 1.51 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 7.09 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.10 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.45, and the maximum semi-FOV of the optical imaging system is 63.2°.

[0096] Table 3 shows the basic parameters of the optical imaging system of Example 2, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 4-1 and 4-2 show 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.

[0097]

[0098]

[0099] Table 3

[0100] Face number A4 A6 A8 A10 A12 A14 A16 S1 1.6170E-01 -1.5844E-02 -1.4620E-01 2.6740E-01 -2.6910E-01 1.7891E-01 -8.2846E-02 S2 4.0957E-01 -5.6454E+00 1.0034E+02 -1.0293E+03 6.7984E+03 -3.0641E+04 9.7424E+04 S3 1.0798E-01 -2.0955E+00 2.0666E+01 -1.2078E+02 4.3666E+02 -9.8719E+02 1.3582E+03 S4 -1.4469E-02 4.4094E-01 -2.5182E+00 6.9127E+00 -1.1170E+01 1.1131E+01 -6.7254E+00 S5 5.1114E-02 -2.5317E-02 -1.1940E-01 -1.1342E+00 8.5115E+00 -2.6472E+01 4.9892E+01 S6 3.9893E-01 -8.3197E+00 5.4818E+01 -2.0909E+02 5.2284E+02 -9.0775E+02 1.1301E+03 S7 5.7577E-01 -7.4900E+00 5.4925E+01 -2.2949E+02 6.1868E+02 -1.1491E+03 1.5241E+03 S8 -1.7305E-01 2.9792E+00 -1.4530E+01 4.9407E+01 -1.2541E+02 2.3616E+02 -3.2657E+02 S9 -2.7235E-01 1.7850E+00 -7.6108E+00 2.0128E+01 -3.6151E+01 4.5848E+01 -4.1794E+01 S10 1.4187E-01 -9.7361E-01 4.1979E+00 -1.1195E+01 1.9309E+01 -2.2749E+01 1.8989E+01

[0101] Table 4-1

[0102] Face number A18 A20 A22 A24 A26 A28 A30 S1 2.7259E-02 -6.3896E-03 1.0536E-03 -1.1840E-04 8.5182E-06 -3.4561E-07 5.7395E-09 S2 -2.2240E+05 3.6632E+05 -4.3203E+05 3.5611E+05 -1.9502E+05 6.3807E+04 -9.4468E+03 S3 -1.0401E+03 3.4000E+02 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 2.2596E+00 -3.2374E-01 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 -6.3024E+01 5.5266E+01 -3.3813E+01 1.4174E+01 -3.8812E+00 6.2535E-01 -4.4952E-02 S6 -1.0256E+03 6.8073E+02 -3.2729E+02 1.1102E+02 -2.5197E+01 3.4335E+00 -2.1234E-01 S7 -1.4697E+03 1.0341E+03 -5.2566E+02 1.8797E+02 -4.4831E+01 6.3967E+00 -4.1265E-01 S8 3.2986E+02 -2.4191E+02 1.2712E+02 -4.6597E+01 1.1307E+01 -1.6318E+00 1.0601E-01 S9 2.7574E+01 -1.3138E+01 4.4630E+00 -1.0509E+00 1.6248E-01 -1.4784E-02 5.9726E-04 S10 -1.1452E+01 5.0152E+00 -1.5806E+00 3.4920E-01 -5.1291E-02 4.4936E-03 -1.7749E-04

[0103] Table 4-2

[0104] Figure 4A 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 4B The distortion curves of the optical imaging system of Example 2 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 4C The relative illumination curves of the optical imaging system of Example 2 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 4A to 4C It can be seen that the optical imaging system given in Example 2 can achieve good imaging quality.

[0105] Example 3

[0106] The following is for reference Figures 5 to 6C An optical imaging system according to Embodiment 3 of this application is described. Figure 5 A schematic diagram of the structure of an optical imaging system according to Embodiment 3 of this application is shown.

[0107] like Figure 5As 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.

[0108] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0109] In this example, the effective focal length f of the optical imaging system is 1.55 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 6.42 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.10 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.23, and the maximum semi-FOV of the optical imaging system is 81.5°.

[0110] Table 5 shows the basic parameters of the optical imaging system of Example 3, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 6-1 and 6-2 show 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.

[0111]

[0112] Table 5

[0113]

[0114]

[0115] Table 6-1

[0116] Face number A18 A20 A22 A24 A26 A28 A30 S1 -6.2592E-02 2.5055E-02 -7.1602E-03 1.4169E-03 -1.8408E-04 1.4105E-05 -4.8283E-07 S2 7.3493E+04 -1.3184E+05 1.6807E+05 -1.4866E+05 8.6715E+04 -2.9998E+04 4.6609E+03 S3 1.6935E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 -8.4957E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 -1.7286E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 -1.4499E-02 1.8366E-03 -1.0611E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 5.5714E-03 -4.5571E-04 -8.4322E-06 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 -1.5436E-01 3.0701E-02 -2.5846E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S9 -5.3011E-02 -6.2558E-03 5.1996E-03 -7.1159E-04 0.0000E+00 0.0000E+00 0.0000E+00 S10 4.5268E+00 -2.3275E+00 8.2617E-01 -1.9962E-01 3.1384E-02 -2.8964E-03 1.1910E-04

[0117] Table 6-2

[0118] Figure 6A The astigmatism curves of the optical imaging system of Example 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6B The distortion curves of the optical imaging system of Example 3 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 6C The relative illumination curves of the optical imaging system of Example 3 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 6A to 6C It can be seen that the optical imaging system given in Example 3 can achieve good imaging quality.

[0119] Example 4

[0120] The following is for reference Figures 7 to 8C An optical imaging system according to Embodiment 4 of this application is described. Figure 7 A schematic diagram of the structure of an optical imaging system according to Embodiment 4 of this application is shown.

[0121] like Figure 7 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.

[0122] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0123] In this example, the effective focal length f of the optical imaging system is 1.55 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 7.91 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.11 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.45, and the maximum semi-FOV of the optical imaging system is 64.5°.

[0124] Table 7 shows the basic parameters of the optical imaging system of Example 4, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 8-1 and 8-2 show 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.

[0125]

[0126] Table 7

[0127] Face number A4 A6 A8 A10 A12 A14 A16 S1 5.3323E-01 -1.6165E+00 3.5937E+00 -5.2853E+00 5.3295E+00 -3.8050E+00 1.9636E+00 S2 -2.4386E+00 9.1931E+01 -1.6003E+03 1.6865E+04 -1.1739E+05 5.6690E+05 -1.9542E+06 S3 -2.3467E-02 4.8472E-02 3.7710E+00 -4.7426E+01 2.6995E+02 -8.5459E+02 1.5488E+03 S4 -8.4007E-02 4.5696E-01 -1.3569E+00 2.5075E+00 -2.9879E+00 2.2988E+00 -1.1063E+00 S5 8.8641E-02 -1.5137E+00 1.0144E+01 -3.9024E+01 9.6898E+01 -1.6474E+02 1.9815E+02 S6 -1.3786E-01 8.9671E-01 -7.9404E+00 3.4481E+01 -8.8834E+01 1.5113E+02 -1.7855E+02 S7 4.5165E-01 -1.7653E+00 4.2261E+00 -2.4622E+00 -1.2778E+01 4.0751E+01 -6.2822E+01 S8 9.3982E-02 9.4196E-02 -1.2548E+00 5.2677E+00 -1.2000E+01 1.7227E+01 -1.6716E+01 S9 -1.7737E-01 1.8797E-01 -2.0475E-01 3.0155E-01 -5.0336E-01 6.3227E-01 -5.3936E-01 S10 -1.6134E-01 6.9902E-01 -1.9456E+00 3.4881E+00 -4.1964E+00 3.5099E+00 -2.0860E+00

[0128] Table 8-1

[0129]

[0130]

[0131] Table 8-2

[0132] Figure 8A The astigmatism curves of the optical imaging system of Example 4 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 8B The distortion curves of the optical imaging system of Example 4 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 8C The relative illumination curves of the optical imaging system of Example 4 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 8A to 8C It can be seen that the optical imaging system given in Example 4 can achieve good imaging quality.

[0133] Example 5

[0134] The following is for reference Figures 9 to 10C An optical imaging system according to Embodiment 5 of this application is described. Figure 9 A schematic diagram of the structure of an optical imaging system according to Embodiment 5 of this application is shown.

[0135] like Figure 9 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.

[0136] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0137] In this example, the effective focal length f of the optical imaging system is 1.51 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 6.43 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.10 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.45, and the maximum semi-FOV of the optical imaging system is 70.9°.

[0138] Table 9 shows the basic parameters of the optical imaging system of Example 5, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 10-1 and 10-2 show 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.

[0139]

[0140]

[0141] Table 9

[0142] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.4613E-01 -1.5687E-01 -2.7273E-02 3.8074E-01 -7.6905E-01 9.3184E-01 -7.6974E-01 S2 4.4348E-01 -3.4359E+00 6.7997E+01 -8.6691E+02 7.3787E+03 -4.3505E+04 1.8192E+05 S3 4.2799E-02 -9.3651E-01 1.4510E+01 -1.3582E+02 7.7272E+02 -2.6915E+03 5.6020E+03 S4 5.3255E-02 -1.9701E-01 4.0883E-01 -6.7979E-01 9.1807E-01 -9.1879E-01 6.0070E-01 S5 7.3701E-02 -3.0937E-01 8.6806E-01 -1.8386E+00 2.6865E+00 -2.3037E+00 3.0383E-01 S6 -9.7400E-02 -1.5438E+00 1.2373E+01 -4.9232E+01 1.2269E+02 -2.0691E+02 2.4647E+02 S7 2.4114E-01 -1.4918E+00 1.1640E+01 -4.8359E+01 1.2399E+02 -2.1315E+02 2.5749E+02 S8 2.1710E-01 -1.3383E+00 9.5216E+00 -3.8224E+01 9.8591E+01 -1.7552E+02 2.2372E+02 S9 -3.8684E-02 -8.0103E-01 5.0233E+00 -1.7408E+01 3.8588E+01 -5.8485E+01 6.2775E+01 S10 2.4546E-01 -1.0526E+00 3.3299E+00 -7.8096E+00 1.3094E+01 -1.5821E+01 1.3947E+01

[0143] Table 10-1

[0144] Face number A18 A20 A22 A24 A26 A28 A30 S1 4.5011E-01 -1.8833E-01 5.6049E-02 -1.1587E-02 1.5814E-03 -1.2812E-04 4.6656E-06 S2 -5.4635E+05 1.1812E+06 -1.8214E+06 1.9531E+06 -1.3833E+06 5.8159E+05 -1.0990E+05 S3 -6.3917E+03 3.0737E+03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 -2.2132E-01 3.4455E-02 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 1.9648E+00 -2.7799E+00 2.0372E+00 -9.2077E-01 2.5797E-01 -4.1228E-02 2.8800E-03 S6 -2.1224E+02 1.3316E+02 -6.0437E+01 1.9355E+01 -4.1512E+00 5.3518E-01 -3.1348E-02 S7 -2.2417E+02 1.4191E+02 -6.4932E+01 2.0966E+01 -4.5385E+00 5.9184E-01 -3.5176E-02 S8 -2.0759E+02 1.4059E+02 -6.8774E+01 2.3658E+01 -5.4276E+00 7.4533E-01 -4.6327E-02 S9 -4.8526E+01 2.7102E+01 -1.0829E+01 3.0153E+00 -5.5514E-01 6.0677E-02 -2.9785E-03 S10 -9.0274E+00 4.2799E+00 -1.4670E+00 3.5346E-01 -5.6727E-02 5.4403E-03 -2.3570E-04

[0145] Table 10-2

[0146] Figure 10A The astigmatism curves of the optical imaging system of Example 5 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 10B The distortion curves of the optical imaging system of Example 5 are shown, which represent the distortion magnitude values ​​corresponding to different field of view angles. Figure 10C The relative illumination curves of the optical imaging system of Example 5 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 10A to 10C It can be seen that the optical imaging system given in Example 5 can achieve good imaging quality.

[0147] Example 6

[0148] The following is for reference Figures 11 to 12C An optical imaging system according to Embodiment 6 of this application is described. Figure 11 A schematic diagram of the structure of an optical imaging system according to Embodiment 6 of this application is shown.

[0149] like Figure 11As 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.

[0150] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0151] In this example, the effective focal length f of the optical imaging system is 1.52 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 7.41 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.11 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.45, and the maximum semi-FOV of the optical imaging system is 63.0°.

[0152] Table 11 shows the basic parameters of the optical imaging system of Example 6, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 12-1 and 12-2 show the higher-order coefficients that can be used for each aspherical mirror in Example 6, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0153]

[0154] Table 11

[0155]

[0156]

[0157] Table 12-1

[0158] Face number A18 A20 A22 A24 A26 A28 A30 S1 -1.4114E-02 -1.7871E-04 9.4385E-04 -2.7294E-04 3.9870E-05 -3.0996E-06 1.0211E-07 S2 1.9336E+06 -3.2896E+06 3.9988E+06 -3.3811E+06 1.8853E+06 -6.2185E+05 9.1647E+04 S3 -1.2096E+02 3.6711E+01 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S4 2.4968E+00 -3.4821E-01 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S5 4.9455E+01 -3.0299E+01 1.3260E+01 -3.9923E+00 7.7356E-01 -8.4733E-02 3.8030E-03 S6 -3.1830E+02 2.1045E+02 -1.0143E+02 3.4667E+01 -7.9597E+00 1.1002E+00 -6.9108E-02 S7 -1.7964E+02 1.2266E+02 -6.1576E+01 2.2078E+01 -5.3433E+00 7.8038E-01 -5.1826E-02 S8 8.3224E+01 -4.9165E+01 2.1068E+01 -6.3680E+00 1.2868E+00 -1.5595E-01 8.5698E-03 S9 8.8104E+00 -3.7479E+00 1.1475E+00 -2.4637E-01 3.5202E-02 -3.0066E-03 1.1615E-04 S10 4.5632E+00 -2.0344E+00 6.4892E-01 -1.4435E-01 2.1260E-02 -1.8625E-03 7.3450E-05

[0159] Table 12-2

[0160] Figure 12A The astigmatism curves of the optical imaging system of Example 6 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 12B The distortion curves of the optical imaging system of Example 6 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 12C The relative illumination curves of the optical imaging system of Example 6 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 12A to 12C As can be seen, the optical imaging system given in Example 6 can achieve good imaging quality.

[0161] Example 7

[0162] The following is for reference Figures 13 to 14C An optical imaging system according to Embodiment 7 of this application is described. Figure 13 A schematic diagram of the structure of an optical imaging system according to Embodiment 7 of this application is shown.

[0163] like Figure 13 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.

[0164] The first lens E1 has negative optical power, with its object-side surface S1 being concave and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being concave and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The filter E6 has an object-side surface S11 and an image-side surface S12. Light from the object passes sequentially through each surface S1 to S12 and is finally imaged on the imaging surface S13.

[0165] In this example, the effective focal length f of the optical imaging system is 1.54 mm, the total length TTL of the optical imaging system (i.e., the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S13 of the optical imaging system) is 6.42 mm, half the diagonal length ImgH of the effective pixel area on the imaging surface S13 of the optical imaging system is 2.10 mm, the ratio f / EPD of the effective focal length f of the optical imaging system to the entrance pupil diameter EPD of the optical imaging system is 1.23, and the maximum semi-FOV of the optical imaging system is 81.7°.

[0166] Table 13 shows the basic parameters of the optical imaging system of Example 7, wherein the units of radius of curvature, thickness and effective focal length are millimeters (mm). Tables 14-1 and 14-2 show the higher-order coefficients that can be used for each aspherical mirror in Example 7, wherein each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0167]

[0168] Table 13

[0169] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.1197E-01 -1.8958E-01 2.5700E-01 -3.9552E-01 5.1640E-01 -5.0800E-01 3.6617E-01 S2 2.5160E-01 1.7368E+00 -4.0104E+01 4.8768E+02 -3.6861E+03 1.8607E+04 -6.5311E+04 S3 -9.8640E-03 -8.0189E-02 3.1171E-01 -7.4725E-01 1.1128E+00 -9.6810E-01 4.0686E-01 S4 4.8085E-02 -7.4548E-02 6.7247E-02 -3.0249E-02 1.3184E-03 3.9370E-03 -1.0184E-03 S5 4.0662E-02 -8.3908E-02 8.4792E-02 -5.3686E-02 2.0187E-02 -4.0302E-03 3.3112E-04 S6 -1.9651E-01 2.8733E-01 -2.3259E-01 1.1620E-01 -3.6500E-02 5.8416E-03 3.7205E-04 S7 1.9702E-01 8.3721E-02 -2.9305E-01 3.5679E-01 -2.6321E-01 1.2025E-01 -3.2759E-02 S8 9.6037E-02 2.2613E-01 -5.2432E-01 5.7825E-01 -3.6953E-01 1.3797E-01 -2.8534E-02 S9 -1.5803E-01 1.7941E-01 -2.0155E-01 -8.7464E-02 6.2645E-01 -9.5539E-01 8.0076E-01 S10 2.0087E-01 -9.1989E-01 2.6644E+00 -5.3248E+00 7.3694E+00 -7.2213E+00 5.1093E+00

[0170] Table 14-1

[0171]

[0172]

[0173] Table 14-2

[0174] Figure 14A The astigmatism curves of the optical imaging system of Embodiment 7 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 14B The distortion curves of the optical imaging system of Example 7 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. Figure 14C The relative illumination curves of the optical imaging system of Example 7 are shown, representing the relative illumination values ​​corresponding to different image heights. According to... Figures 14A to 14C As can be seen, the optical imaging system given in Example 7 can achieve good imaging quality.

[0175] In summary, Examples 1 to 7 satisfy the relationships shown in Table 15.

[0176]

[0177]

[0178] Table 15

[0179] 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.

[0180] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An optical imaging system, characterized in that, Along the optical axis from the object side to the image side, it includes, in sequence: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; wherein, The first lens has negative optical power, and its object side is concave, and its image side is concave; The second lens and the third lens have positive optical power; The object-side surface of the second lens is concave, and the image-side surface is convex. The object-side surface of the third lens is convex, and the image-side surface is also convex. The object-side surface of the fourth lens is concave, and the image-side surface is convex. The object-side surface of the fifth lens is convex. The fourth lens and the fifth lens have opposite positive and negative optical power properties; The radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: 3.69≤R3 / R4≤8.19; The radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: -2.00≤R5 / R6≤-0.80; The maximum semi-field-of-view (Semi-FOV) of the optical imaging system satisfies: 81.7° ≥ Semi-FOV > 60.0°; and The effective focal length f of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy the following condition: 1.23 ≤ f / EPD < 1.5; The effective focal length f2 of the second lens and the effective focal length f of the optical imaging system satisfy: 1.91≤f2 / f≤2.42; The optical imaging system has five lenses with optical power.

2. The optical imaging system according to claim 1, wherein, The effective focal length f of the optical imaging system and the effective focal length f1 of the first lens satisfy the following conditions: 1.5mm≤f≤1.6mm and -2.31≤f1 / f<-1.

5.

3. The optical imaging system according to claim 1, wherein, The effective focal length f2 of the second lens, the radius of curvature R3 of the object side of the second lens, and the radius of curvature R4 of the image side of the second lens satisfy: -0.41≤f2 / (R3+R4)≤-0.

19.

4. The optical imaging system according to claim 1, wherein, The central thickness CT3 of the third lens on the optical axis, the radius of curvature R5 of the object side of the third lens, and the radius of curvature R6 of the image side of the third lens satisfy: 0.16≤CT3 / (R5-R6)≤0.

23.

5. The optical imaging system according to claim 1, wherein, The effective focal length f3 of the third lens and the effective focal length f of the optical imaging system satisfy the following condition: 1.79≤f3 / f≤2.

42.

6. The optical imaging system according to claim 1, wherein, The center thickness CT3 of the third lens on the optical axis and the center thickness CT4 of the fourth lens on the optical axis satisfy the following condition: CT3 > 1.0 mm > CT4.

7. The optical imaging system according to claim 1, wherein, The center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: 0.76≤CT2 / f2+CT3 / f3≤0.

88.

8. The optical imaging system according to claim 1, wherein, The entrance pupil diameter EPD of the optical imaging system, the maximum effective radius DT12 of the image side of the first lens, and the maximum effective radius DT21 of the object side of the second lens satisfy the following condition: 2.45≤EPD / DT12+EPD / DT21≤2.

86.

9. The optical imaging system according to claim 1, wherein, The maximum effective radius DT42 of the image side of the fourth lens, the maximum effective radius DT51 of the object side of the fifth lens, the radius of curvature R8 of the image side of the fourth lens, and the radius of curvature R9 of the object side of the fifth lens satisfy: 1.19≥DT51 / DT42≥1.0 and -2.52≤R8 / DT42-R9 / DT51≤-1.

79.

10. The optical imaging system according to any one of claims 1 to 9, wherein, The axial distance TOL from the object to the object-side surface of the first lens satisfies: 0 mm <TOL<500mm。 11. The optical imaging system according to any one of claims 1 to 9, wherein, The effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the refractive index N2 of the second lens, the refractive index N3 of the third lens, and the combined focal length f23 of the second lens and the third lens satisfy: 6.30≤[f2 / (N2-1)+f3 / (N3-1)] / f23<6.

6.

12. The optical imaging system according to any one of claims 1 to 9, wherein, The center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, the edge thickness ET2 of the second lens, the edge thickness ET3 of the third lens, the effective focal length f2 of the second lens, and the effective focal length f3 of the third lens satisfy: CT2>ET2, CT3>ET3, and 0.39≤(CT2-ET2) / f2+(CT3-ET3) / f3<0.

5.

13. The optical imaging system according to any one of claims 1 to 9, wherein, The air gap T45 between the fourth lens and the fifth lens on the optical axis, the center thickness CT5 of the fifth lens on the optical axis, and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0.38≤(T45+CT5) / R9<0.

6.

14. The optical imaging system according to any one of claims 1 to 9, wherein, The maximum effective radius DT11 of the object side of the first lens, the maximum effective radius DT52 of the image side of the fifth lens, and the effective focal length f of the optical imaging system satisfy: 0.10≤(DT11-DT52) / f<0.

4.

15. The optical imaging system according to any one of claims 1 to 9, wherein, The axial distance SAG32 between the intersection of the image-side surface of the third lens and the optical axis to the vertex of the effective radius of the image-side surface of the third lens, the axial distance SAG41 between the intersection of the object-side surface of the fourth lens and the optical axis to the vertex of the effective radius of the object-side surface of the fourth lens, and the radius of curvature R6 of the image-side surface of the third lens and the radius of curvature R7 of the object-side surface of the fourth lens satisfy: 0.33≤SAG32 / R6+SAG41 / R7<1.

0.

16. The optical imaging system according to any one of claims 1 to 9, wherein, The optical imaging system further includes an aperture stop placed between the first lens and the second lens. The on-axis distance SL from the aperture stop to the imaging surface of the optical imaging system and the on-axis distance SD from the aperture stop to the image side surface of the fifth lens satisfy the following condition: 0.69≤SD / SL≤0.

80.

17. The optical imaging system according to any one of claims 1 to 9, wherein, Any two adjacent lenses from the first lens to the fifth lens have an air gap on the optical axis, and the sum of the air gaps ∑AT and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0.73≤T12 / ∑AT≤0.

82.

18. The optical imaging system according to any one of claims 1 to 9, wherein, The axial distance SAG12 between the intersection of the image-side surface of the first lens and the optical axis and the vertex of the effective radius of the image-side surface of the first lens, the axial distance SAG22 between the intersection of the image-side surface of the second lens and the optical axis and the vertex of the effective radius of the image-side surface of the second lens, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the air gap T12 between the first lens and the second lens on the optical axis satisfy: 0.22≤(SAG12+|SAG22|) / (CT1+T12+CT2)≤0.

35.

19. The optical imaging system according to any one of claims 1 to 9, wherein, The optical imaging system operates in the range of 800nm ​​to 1000nm.

Images