Optical imaging systems and electronic devices

Abstract

The present application discloses an optical imaging system and an electronic device. The optical imaging system includes a first element group and a second element group. It is characterized in that the first element group includes a first lens with a positive optical power and a reflecting element; the second element group includes a second lens with a positive optical power, a third lens with a negative optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, and a sixth lens with a positive optical power; wherein, the first element group is located on a first optical axis segment, and the second element group is located on a second optical axis segment; the reflecting element has an incident surface, a reflecting surface, and an exit surface, and the reflecting surface of the reflecting element is located at the connection of the first optical axis segment and the second optical axis segment; half of the maximum field angle of the optical imaging system, Semi-FOV, satisfies: 5° < Semi-FOV < 20°; the central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis satisfy: 1.2 < CT2 / CT1 < 2.5.

Description

Technical Field

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

[0002] In recent years, with the rapid development of smartphones, mobile phone photography has become increasingly important in people's communication, entertainment, and daily lives, making the camera capabilities of mobile phone lenses a focal point of attention. For high-end flagship models from various brands, large aperture and telephoto lenses have become standard features. A large aperture means more light intake, more vibrant images, and better low-light performance; a telephoto lens means the ability to capture distant objects. Furthermore, large aperture telephoto lenses used in the mid-range focal length offer shallow depth of field and vibrant images, effectively blurring the background when shooting portraits and landscape close-ups, highlighting the details and characteristics of the subject.

[0003] Periscope telephoto lenses can make full use of the vertical space of a mobile phone to obtain a very long focal length, and can still produce clear images of objects at a very far distance. However, the prism of a conventional periscope telephoto lens is usually located at the front of the optical system, only providing the function of turning the light path. The lens aperture is also limited by the space of the mobile phone. Therefore, conventional periscope telephoto lenses cannot obtain a large aperture.

[0004] Based on the current state of development of periscope telephoto lenses, in order to meet the application requirements of ultra-telephoto lenses in next-generation flagship mobile phones, designing and developing a periscope optical imaging lens with a large aperture and long focal length has become one of the technical problems that those skilled in the art are currently working to solve. Summary of the Invention

[0005] The present application provides an optical imaging system. The optical imaging system includes a first element group and a second element group arranged in sequence from the object side to the image side along the optical axis. The first element group includes a first lens with a positive optical power and a reflection element; the second element group includes a second lens with a positive optical power, a third lens with a negative optical power, a fourth lens with a negative optical power, a fifth lens with a positive optical power, and a sixth lens with a positive optical power; wherein, the optical axis includes a first optical axis segment and a second optical axis segment, and the first optical axis segment is perpendicular to the second optical axis segment. The first element group is located on the first optical axis segment, and the second element group is located on the second optical axis segment; the reflection element has an incident surface, a reflection surface, and an exit surface, and the reflection surface of the reflection element is located at the connection of the first optical axis segment and the second optical axis segment; the reflection element is configured such that the light emitted from the first lens enters the reflection element through the incident surface along the direction of the first optical axis segment, and after being reflected by the reflection surface, exits through the exit surface along the direction of the second optical axis segment and enters the second lens; half of the maximum field angle of the optical imaging system, Semi - FOV, satisfies: 5° < Semi - FOV < 20°; the central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis satisfy: 1.2 < CT2 / CT1 < 2.5.

[0006] In one embodiment, 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: -1.8 < R3 / R4 < -0.1.

[0007] In one embodiment, the effective focal length f4 of the fourth lens and the effective focal length f of the optical imaging system satisfy: -3.5 < f / f4 < -1.

[0008] In one embodiment, the axial spacing distance T12 between the image side surface of the first lens and the object side surface of the second lens on the optical axis and the sum ∑AT of the axial spacing distances between any two adjacent lenses among the first lens to the fifth lens satisfy: 0.65 < T12 / ∑AT < 1.

[0009] In one embodiment, the optical imaging system further includes an aperture stop, and the axial distance SL from the aperture stop to the imaging surface of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy: 1.9 < SL / EPD < 2.5.

[0010] In one embodiment, the effective focal length f4 of the fourth lens and the effective focal length f6 of the sixth lens satisfy: -1.8 < f4 / f6 < -0.1.

[0011] In one embodiment, the effective focal length f1 of the first lens and the effective focal length f of the optical imaging system satisfy: 3 < f1 / f < 4.

[0012] In one embodiment, the central thicknesses of at least two lenses among the first lens to the fifth lens on the optical axis are greater than 1 mm.

[0013] In one embodiment, the effective focal length f2 of the second lens and the combined focal length f34 of the third and fourth lenses satisfy: -2.5 <f2 / f34<-0.1。

[0014] In one embodiment, the radius of curvature R5 of the object-side surface of the third lens, the radius of curvature R6 of the image-side surface of the third lens, and the combined focal length f234 of the second, third, and fourth lenses satisfy: 1mm <R5×R6 / f234<7mm。

[0015] In one embodiment, the distance T34 between the third and fourth lenses on the optical axis and the distance T45 between the fourth and fifth lenses on the optical axis satisfy: 0.06 ≤ T45 / T34 < 1.3.

[0016] In one embodiment, the distance T23 between the second lens and the third lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, and the center thickness CT3 of the third lens on the optical axis satisfy: 5.16≤(CT2-CT3) / T23<8.8.

[0017] In one embodiment, the center thickness CT5 of the fifth lens on the optical axis and the spacing T45 between the fourth and fifth lenses on the optical axis satisfy: 0 <T45 / CT5<0.8。

[0018] In one embodiment, the axial distance SAG12 between the intersection of the image-side surface of the first lens and the first optical axis segment to the vertex of the effective radius of the image-side surface of the first lens, and the axial distance SAG22 between the intersection of the image-side surface of the second lens and the second optical axis segment to the vertex of the effective radius of the image-side surface of the second lens, satisfy: -2.8 <SAG12 / SAG22<-1.5。

[0019] In one embodiment, the axial distance SAG11 between the intersection of the object-side surface of the first lens and the first optical axis and the vertex of the effective radius of the object-side surface of the first lens, and the axial distance SAG21 between the intersection of the object-side surface of the second lens and the second optical axis and the vertex of the effective radius of the object-side surface of the second lens, satisfy: 1 <SAG11 / SAG21<1.8。

[0020] In one embodiment, the object-side surfaces of both the first lens and the fifth lens are convex, and the image-side surfaces are both concave.

[0021] In one embodiment, both the object-side and image-side surfaces of the second lens are convex.

[0022] In one embodiment, both the object-side and image-side surfaces of the third lens are concave.

[0023] In one embodiment, the image-side surface of the fourth lens is concave, and the object-side surface of the sixth lens is convex.

[0024] Another aspect of this application provides an electronic device that may include an optical imaging system according to the above embodiments and an imaging element for converting an optical image formed by the optical imaging system into an electrical signal.

[0025] The optical imaging system provided in this application employs a six-lens, one-reflective-element design for the refracting optical path. The reflective element is positioned in the center of the optical imaging system, serving a certain imaging function. Furthermore, the first lens is located at the very front of the optical system; therefore, the aperture of the first lens is not limited by the space constraints of the mobile phone, allowing the optical imaging system to have a larger aperture. By rationally allocating the optical power of each lens and reasonably constraining the field of view, the thickness of the first lens, and the second lens, this application can better achieve a long focal length design while ensuring sufficient space for the reflective element at the module end. Simultaneously, it enables the second lens to have greater deflection capability for edge rays, ensuring that the optical imaging system possesses the characteristics of a large aperture, long focal length, and high image quality. Attached Figure Description

[0026] 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:

[0027] Figure 1 A schematic diagram of the structure of an optical imaging system according to Embodiment 1 of this application is shown;

[0028] Figures 2A to 2D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical imaging system of Example 1 are shown respectively.

[0029] Figure 3 A schematic diagram of the structure of an optical imaging system according to Embodiment 2 of this application is shown;

[0030] Figures 4A to 4D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical imaging system of Example 2 are shown respectively.

[0031] Figure 5 A schematic diagram of the structure of an optical imaging system according to Embodiment 3 of this application is shown;

[0032] Figures 6A to 6D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical imaging system of Example 3 are shown respectively.

[0033] Figure 7 A schematic diagram of the structure of an optical imaging system according to Embodiment 4 of this application is shown;

[0034] Figures 8A to 8D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical imaging system of Example 4 are shown respectively.

[0035] Figure 9 A schematic diagram of the structure of an optical imaging system according to Embodiment 5 of this application is shown;

[0036] Figures 10A to 10D The on-axis chromatic aberration curve, astigmatism curve, distortion curve, and magnification chromatic aberration curve of the optical imaging system of Example 5 are shown respectively; and

[0037] Figure 11 A schematic diagram of the structure of an electronic device according to an exemplary embodiment of this application is shown. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The features, principles and other aspects of this application are described in detail below.

[0046] An optical imaging system according to an exemplary embodiment of this application may include a first element group and a second element group arranged sequentially along an optical axis from the object side to the image side. The optical axis may be a deflected optical axis, which may include a first optical axis segment and a second optical axis segment, and the first optical axis segment is perpendicular to the second optical axis segment. The first element group is located in the first optical axis segment, and the second element group is located in the second optical axis segment. The first element group may include a first lens with positive optical power and a reflecting element; the second element group may include a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power. The first lens and the reflecting element are arranged sequentially along the first optical axis segment from the object side to the image side, and the second, third, fourth, fifth, and sixth lenses are arranged sequentially along the second optical axis segment from the object side to the image side.

[0047] In an exemplary embodiment, the reflective element has an incident surface, a reflective surface, and an exit surface. The reflective surface of the reflective element is located at the connection of the first optical axis segment and the second optical axis segment. The reflective element is configured such that the light emitted from the first lens enters the reflective element through the incident surface along the direction of the first optical axis segment, is reflected by the reflective surface, and then exits through the exit surface along the direction of the second optical axis segment into the second lens. In this application, a reflective element is introduced between the lenses, achieving the effect of turning the optical path of the optical imaging system. Exemplarily, the reflective element is a prism.

[0048] In an exemplary embodiment, half of the maximum field angle of the optical imaging system, Semi - FOV, satisfies: 5° < Semi - FOV < 20°. The central thickness CT1 of the first lens on the optical axis and the central thickness CT2 of the second lens on the optical axis satisfy: 1.2 < CT2 / CT1 < 2.5. Reasonably constraining the field angle of the optical imaging system and the thicknesses of the first and second lenses can better achieve a long - focal - length design, while ensuring the space for placing the reflective element and enabling the second lens to have a greater deflection ability for marginal rays.

[0049] In an exemplary embodiment, half of the diagonal length of the effective pixel area on the imaging surface of the optical imaging system, ImgH, satisfies: ImgH > 4.0 mm. ImgH can be, for example, in the range of 4.10 mm to 4.35 mm.

[0050] In an exemplary embodiment, the optical imaging system according to this application can satisfy: f > 18 mm, where f is the effective focal length of the optical imaging system. f can be, for example, in the range of 18.50 mm to 20.10 mm. Satisfying f > 18 mm is beneficial for the optical imaging system to have a longer effective focal length and achieve a telephoto effect.

[0051] In an exemplary embodiment, the optical imaging system may further include an aperture for restricting the light beam to further improve the imaging quality of the optical imaging system. Exemplarily, the aperture can be disposed between the second lens and the reflective element. The aperture is beneficial for converging the light rays entering the optical imaging system, shortening the total length of the optical imaging system, reducing the maximum clear aperture of the optical imaging system, facilitating miniaturization, and reducing the assembly sensitivity of the system. However, it should be noted that the position of the aperture disclosed here is only an example and not a limitation; in alternative embodiments, the aperture can also be disposed at other positions according to actual needs.

[0052] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: -1.8 < R3 / R4 < -0.1, where R3 is the radius of curvature of the object side surface of the second lens, and R4 is the radius of curvature of the image side surface of the second lens. Satisfying -1.8 < R3 / R4 < -0.1 is beneficial to reasonably constrain the shape of the second lens, correct the off-axis chromatic aberration, ensure the lens processability, and satisfy the CRA matching of each field of view.

[0053] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: -3.5 < f / f4 < -1, where f4 is the effective focal length of the fourth lens, and f is the effective focal length of the optical imaging system. Satisfying -3.5 < f / f4 < -1 is beneficial to reasonably constrain the negative optical power of the fourth lens to correct the off-axis field curvature and astigmatism and improve the imaging quality.

[0054] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.65 < T12 / ∑AT < 1, where T12 is the axial distance from the image side surface of the first lens to the object side surface of the second lens, and ∑AT is the sum of the axial distances between any two adjacent lenses from the first lens to the fifth lens. More specifically, T12 is the sum of the distance from the center of the image side surface of the first lens to the center of the reflecting surface of the reflecting element on the first optical axis segment and the distance from the center of the reflecting surface of the reflecting element to the center of the object side surface of the second lens along the second optical axis segment. Satisfying 0.65 < T12 / ∑AT < 1 is beneficial to control the spacing between the lenses, constrain the total length of the optical imaging system, and ensure the assembly space required for module end alignment and centering.

[0055] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 1.9 < SL / EPD < 2.5, where SL is the axial distance from the aperture to the imaging surface of the optical imaging system, and EPD is the entrance pupil diameter of the optical imaging system. Satisfying 1.9 < SL / EPD < 2.5 is beneficial to reasonably control the position and size of the aperture stop, improve the off-axis aberration, increase the resolution, and obtain a larger aperture at the same time.

[0056] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: -1.8 < f4 / f6 < -0.1, where f4 is the effective focal length of the fourth lens, and f6 is the effective focal length of the sixth lens. Satisfying -1.8 < f4 / f6 < -0.1 is beneficial to adjust the optical powers of the fourth lens and the sixth lens, correct the field curvature, improve the CRA matching of off-axis rays, and improve the imaging quality of the lens in macro mode.

[0057] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 3 < f1 / f < 4, where f1 is the effective focal length of the first lens and f is the effective focal length of the optical imaging system. Satisfying 3 < f1 / f < 4 is beneficial to controlling the optical power of the first lens, increasing the light deflection, increasing the distance between the first lens and the reflection element, and reserving sufficient space for placing devices such as motors in the module and improving the ghost images and stray light of the reflection element.

[0058] In an exemplary embodiment, the central thickness on the optical axis of at least two of the first lens to the fifth lens of the optical imaging system according to the present application is greater than 1 mm. Since there is a certain risk of MTF reliability variation for high-refractive-index and negative-power lenses after lens edging, the thickness of high-refractive-index and negative-power lenses in the optical imaging system cannot be too large, and the thickness of the remaining lenses needs to be increased accordingly to compensate for part of the optical power. Therefore, the central thickness on the optical axis of at least two of the first lens to the fifth lens is greater than 1 mm.

[0059] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: -2.5 < f2 / f34 < -0.1, where f2 is the effective focal length of the second lens and f34 is the combined focal length of the third lens and the fourth lens. The second lens is a positive lens with a relatively large optical power, which will introduce较多 off-axis aberrations and chromatic aberrations. Satisfying -2.5 < f2 / f34 < -0.1 and reasonably controlling the focal lengths of the third lens and the fourth lens is beneficial to controlling the shapes of the third and fourth lenses to improve the imaging quality.

[0060] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 1 mm < R5×R6 / f234 < 7 mm, where R5 is the curvature radius of the object side surface of the third lens, R6 is the curvature radius of the image side surface of the third lens, and f234 is the combined focal length of the second lens, the third lens, and the fourth lens. Satisfying 1 mm < R5×R6 / f234 < 7 mm is beneficial to reasonably controlling the shapes and materials of the second, third, and fourth lenses, correcting system aberrations, improving system sensitivity, and reducing the edging ratio of the lenses.

[0061] In an exemplary embodiment, the optical imaging system according to the present application may satisfy: 0.06 ≤ T45 / T34 < 1.3, where T34 is the spacing distance on the optical axis between the third lens and the fourth lens, and T45 is the spacing distance on the optical axis between the fourth lens and the fifth lens. Satisfying 0.06 ≤ T45 / T34 < 1.3 is beneficial to ensuring a reasonable minimum distance between the lenses, reducing the difficulty of lens assembly, and improving the stability and mass production performance of lens assembly.

[0062] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: 5.16 ≤ (CT2 - CT3) / T23 < 8.8, where T23 is the distance between the second lens and the third lens on the optical axis, CT2 is the central thickness of the second lens on the optical axis, and CT3 is the central thickness of the third lens on the optical axis. The second lens is a positive lens and the third lens is a negative lens. Satisfying 5.16 ≤ (CT2 - CT3) / T23 < 8.8 is beneficial to reasonably constrain the shapes of the positive and negative lenses, making them close to being cemented, which is beneficial to correcting the axial chromatic aberration and secondary spectrum of the optical system.

[0063] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: 0 < T45 / CT5 < 0.8, where CT5 is the central thickness of the fifth lens on the optical axis, and T45 is the distance between the fourth lens and the fifth lens on the optical axis. Satisfying 0 < T45 / CT5 < 0.8 is beneficial to reasonably constrain the thickness and the distance between the fourth and fifth lenses, reducing the size of the lens group, avoiding excessive volume, while reducing the assembly difficulty of the lenses and achieving a high space utilization rate.

[0064] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: -2.8 < SAG12 / SAG22 < -1.5, where SAG12 is the axial distance between the intersection point of the image side of the first lens and the first optical axis segment and the vertex of the effective radius of the image side of the first lens, and SAG22 is the axial distance between the intersection point of the image side of the second lens and the second optical axis segment and the vertex of the effective radius of the image side of the second lens. Satisfying -2.8 < SAG12 / SAG22 < -1.5 is beneficial to reasonably control the sagittal heights of the first lens and the second lens, enabling them to have a strong light-gathering ability while ensuring processability, reducing the subsequent ray height, and being beneficial to reducing the trimming ratio of the subsequent group of lenses.

[0065] In an exemplary embodiment, the optical imaging system according to the present application can satisfy: 1 < SAG11 / SAG21 < 1.8, where SAG11 is the axial distance between the intersection point of the object side of the first lens and the first optical axis and the vertex of the effective radius of the object side of the first lens, and SAG21 is the axial distance between the intersection point of the object side of the second lens and the second optical axis and the vertex of the effective radius of the object side of the second lens. Satisfying 1 < SAG11 / SAG21 < 1.8, reasonably controlling the sagittal heights of the first lens and the second lens, is beneficial to reducing the trimming ratio, and is also beneficial to improving off-axis aberration, while ensuring the light transmission amount and relative illumination of the lens.

[0066] In an exemplary embodiment, the object-side surfaces of the first lens and the fifth lens are both convex, and the image-side surfaces of both lenses are concave. The object-side and image-side surfaces of the second lens are both convex. The object-side and image-side surfaces of the third lens are both concave. The image-side surface of the fourth lens is concave, and the object-side surface of the sixth lens is convex.

[0067] In an exemplary embodiment, the effective focal length f1 of the first lens of the optical imaging system can be, for example, in the range of 66.0 mm to 72.5 mm, the effective focal length f2 of the second lens can be, for example, in the range of 5.5 mm to 7.0 mm, the effective focal length f3 of the third lens can be, for example, in the range of -8.0 mm to -4.5 mm, the effective focal length f4 of the fourth lens can be, for example, in the range of -12.2 mm to -6.5 mm, the effective focal length f5 of the fifth lens can be, for example, in the range of 41.0 mm to 182.0 mm, and the effective focal length f6 of the sixth lens can be, for example, in the range of 8.0 mm to 11.0 mm.

[0068] 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.

[0069] This application proposes an optical imaging system with a folding optical path design. The optical imaging system according to the above embodiments of this application can employ multiple lenses, such as the six lenses mentioned above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis spacing between lenses, the low-order aberrations of the optical imaging system can be effectively balanced and controlled, while reducing its tolerance sensitivity and maintaining the miniaturization of the optical imaging system.

[0070] In embodiments of this application, at least one of the mirror surfaces of the first to sixth lenses 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 an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, both the object-side and image-side surfaces of each of the first to sixth lenses are aspherical mirror surfaces.

[0071] However, those skilled in the art will understand that the number of lenses constituting the optical imaging system can be varied to obtain the various results and advantages described herein without departing from the technical solutions claimed in this application. For example, although six lenses are described as an example in the embodiments, the optical imaging system is not limited to including six lenses. If desired, 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 2D 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, along the reversing optical axis from the object side to the image side, sequentially includes: a first lens E1, a reflecting element P1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a filter E7. The first lens E1 and the reflecting element P1 are located in the first optical axis segment of the reversing optical axis, while the second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7 are located in the second optical axis segment of the reversing optical axis. More specifically, the reflecting surface of the reflecting element P1 is located at the junction of the first and second optical axis segments of the reversing optical axis.

[0076] In this embodiment, the first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The reflecting element P1 has an incident surface, a reflecting surface, and an exit surface. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. 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 sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. The optical imaging system has an imaging surface S15. Light from the object passes sequentially along the first optical axis segment through the first lens E1 to the reflecting element P1, is reflected by the reflecting element P1 to the second optical axis segment, and then passes sequentially along the second optical axis segment through the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the filter E7, and is finally imaged on the imaging surface S15.

[0077] Table 1 shows the basic parameters of the optical imaging system of Example 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0078]

[0079]

[0080] Table 1

[0081] In Embodiment 1, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0082]

[0083] Where x is the distance vector from the vertex of the aspherical surface at a height of 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, A1, A2, A3, A4, A5, A6, A8, A1 ... 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0084] Face number A4 A6 A8 A10 A12 A14 A16 S1 4.8918E-01 -1.2999E-02 3.2875E-03 -3.8567E-04 5.8342E-05 -1.2741E-05 5.0328E-06 S2 -1.3282E-01 -1.9779E-02 -3.5554E-03 -9.5046E-04 -1.4892E-04 -5.8801E-05 2.9313E-06 S3 -2.6460E-01 -6.0087E-02 -1.6007E-02 -4.9817E-03 -1.6066E-03 -5.7508E-04 -2.1202E-04 S4 6.0511E-02 -1.4001E-02 2.5192E-03 -1.4832E-03 7.4962E-04 -3.1489E-04 2.0711E-04 S5 3.0698E-02 2.3354E-03 2.3926E-03 -8.4990E-04 6.4328E-04 -2.6217E-04 2.0169E-04 S6 -2.9722E-02 3.6181E-03 -1.9747E-03 4.2113E-04 -2.8892E-05 1.5147E-05 7.3579E-05 S7 -1.9637E-01 2.4830E-02 -8.1301E-03 1.9845E-03 -5.3067E-04 2.1132E-04 9.8772E-05 S8 -2.1764E-01 3.2297E-02 -7.0000E-03 1.8960E-03 -7.7453E-04 1.0756E-04 3.1272E-04 S9 1.1740E-01 -1.3184E-02 -3.1188E-04 -8.0121E-04 4.5144E-04 -5.2761E-04 3.2606E-04 S10 1.4087E-02 1.9398E-02 -4.3682E-03 2.4811E-04 1.7650E-03 -1.1039E-03 -7.9692E-06 S11 -9.7320E-02 2.6582E-02 -2.4450E-04 6.7185E-04 1.4736E-03 -7.1378E-04 -8.6304E-05 S12 -1.2509E-01 4.7015E-03 3.4614E-04 1.2564E-04 1.4360E-04 -4.2644E-05 5.3419E-07

[0085] Table 2-1

[0086]

[0087]

[0088] Table 2-2

[0089] Figure 2A The on-axis chromatic aberration curve of the optical imaging system of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 2B 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 2C 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 2D The magnification chromatic aberration curve of the optical imaging system of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 2A to 2D It can be seen that the optical imaging system given in Example 1 can achieve good imaging quality.

[0090] Example 2

[0091] The following is for reference Figures 3 to 4D 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.

[0092] like Figure 3 As shown, the optical imaging system, along the reversing optical axis from the object side to the image side, sequentially includes: a first lens E1, a reflecting element P1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a filter E7. The first lens E1 and the reflecting element P1 are located in the first optical axis segment of the reversing optical axis, while the second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7 are located in the second optical axis segment of the reversing optical axis. More specifically, the reflecting surface of the reflecting element P1 is located at the junction of the first and second optical axis segments of the reversing optical axis.

[0093] In this embodiment, the first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The reflecting element P1 has an incident surface, a reflecting surface, and an exit surface. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being concave. 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 sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. The optical imaging system has an imaging surface S15. Light from the object passes sequentially along the first optical axis segment through the first lens E1 to the reflecting element P1, is reflected by the reflecting element P1 to the second optical axis segment, and then passes sequentially along the second optical axis segment through the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the filter E7, and is finally imaged on the imaging surface S15.

[0094] Table 3 shows the basic parameters of the optical imaging system of Example 2, where the units for radius of curvature and thickness / distance 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, where each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0095]

[0096]

[0097] Table 3

[0098] Face number A4 A6 A8 A10 A12 A14 A16 S1 2.8914E-01 -1.2591E-02 1.8153E-03 -3.6747E-04 5.7727E-05 -1.7222E-05 7.3340E-06 S2 -9.8183E-02 -8.4506E-03 -4.4592E-04 -3.3358E-04 3.3053E-05 -1.9197E-05 8.9167E-06 S3 -2.4838E-01 -5.0498E-02 -1.1646E-02 -3.5565E-03 -1.0428E-03 -3.4935E-04 -1.1348E-04 S4 6.5734E-02 -1.8199E-02 3.2359E-03 -1.6051E-03 1.1117E-03 -4.8653E-04 2.4333E-04 S5 1.7773E-02 -3.0542E-03 3.4448E-04 -4.0488E-04 9.0520E-04 -4.6750E-04 2.3798E-04 S6 -6.2001E-02 2.4783E-03 -3.4924E-03 7.5281E-04 6.7227E-05 -7.2723E-05 3.6727E-05 S7 -1.9160E-01 2.7654E-02 -1.2955E-02 3.2046E-03 -5.9399E-04 7.6395E-05 2.1893E-05 S8 -2.9983E-01 5.4327E-02 -1.8350E-02 4.8350E-03 -1.3785E-03 -5.5949E-05 3.0882E-04 S9 1.6572E-01 -2.3044E-02 4.1443E-03 -1.0221E-03 -3.4214E-06 -2.9953E-04 3.3246E-04 S10 4.3628E-03 3.2964E-02 -8.5260E-03 4.6841E-03 -9.9073E-04 8.2907E-04 -2.2734E-04 S11 -6.9027E-02 -3.5364E-03 6.1825E-03 -1.2701E-04 1.9453E-03 -1.2954E-05 1.3243E-04 S12 -1.4509E-01 2.9545E-03 1.6544E-03 -2.4592E-05 5.9736E-04 -4.6681E-05 5.3492E-05

[0099] Table 4-1

[0100] Face number A18 A20 A22 A24 A26 A28 A30 S1 -3.1900E-06 4.0714E-06 -4.3774E-06 7.8890E-07 -1.4497E-06 1.5260E-06 3.0422E-07 S2 -4.5137E-06 4.4872E-06 -5.2404E-06 1.4047E-06 -1.1176E-06 2.1633E-06 -2.4842E-07 S3 -4.1913E-05 -1.5028E-05 -5.5112E-06 -2.2366E-06 -5.5711E-07 -1.1133E-06 1.4596E-10 S4 -9.6784E-05 4.9271E-05 -2.1951E-05 1.0152E-05 -6.3079E-06 3.6371E-06 -8.1210E-07 S5 -9.8339E-05 4.8108E-05 -2.1415E-05 9.2756E-06 -5.7112E-06 2.9652E-06 -5.0911E-07 S6 -1.4026E-05 7.0911E-06 -2.8729E-06 5.3436E-07 -6.0803E-07 2.1319E-07 4.7049E-07 S7 -1.9555E-05 1.2447E-05 -4.8496E-06 8.0466E-07 -2.0814E-08 -2.3025E-07 6.4279E-07 S8 -2.7305E-04 1.8121E-04 -7.5140E-05 1.1543E-05 6.5024E-06 -8.5277E-06 3.1627E-06 S9 -2.9348E-04 1.9878E-04 -8.7162E-05 1.7787E-05 4.5959E-06 -9.2555E-06 3.4822E-06 S10 6.4434E-06 5.3393E-05 -3.9077E-05 8.7218E-06 -2.9429E-06 -3.5364E-06 -4.6724E-07 S11 -1.3593E-04 8.2498E-05 -6.8126E-05 2.4406E-05 -1.0757E-05 5.3802E-07 -1.8458E-06 S12 -1.5244E-05 1.5235E-05 -6.6070E-06 2.7590E-06 -2.3021E-06 -1.3443E-06 -4.5062E-07

[0101] Table 4-2

[0102] Figure 4A The on-axis chromatic aberration curve of the optical imaging system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 4B 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 4C 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 4D The magnification chromatic aberration curve of the optical imaging system of Embodiment 2 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 4A to 4D It can be seen that the optical imaging system given in Example 2 can achieve good imaging quality.

[0103] Example 3

[0104] The following is for reference Figures 5 to 6D 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.

[0105] like Figure 5 As shown, the optical imaging system, along the reversing optical axis from the object side to the image side, sequentially includes: a first lens E1, a reflecting element P1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a filter E7. The first lens E1 and the reflecting element P1 are located in the first optical axis segment of the reversing optical axis, while the second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7 are located in the second optical axis segment of the reversing optical axis. More specifically, the reflecting surface of the reflecting element P1 is located at the junction of the first and second optical axis segments of the reversing optical axis.

[0106] In this embodiment, the first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The reflecting element P1 has an incident surface, a reflecting surface, and an exit surface. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. 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 sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. The optical imaging system has an imaging surface S15. Light from the object passes sequentially along the first optical axis segment through the first lens E1 to the reflecting element P1, is reflected by the reflecting element P1 to the second optical axis segment, and then passes sequentially along the second optical axis segment through the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the filter E7, and is finally imaged on the imaging surface S15.

[0107] Table 5 shows the basic parameters of the optical imaging system of Example 3, where the units for radius of curvature and thickness / distance 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, where each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0108]

[0109]

[0110] Table 5

[0111] Face number A4 A6 A8 A10 A12 A14 A16 S1 3.9643E-01 -8.2410E-03 1.1368E-03 -3.2982E-04 9.0624E-05 4.6423E-05 2.3953E-05 S2 -2.7419E-02 -5.7606E-03 -5.5768E-04 -2.1148E-04 6.3105E-06 -5.8155E-06 5.5516E-06 S3 -2.1329E-01 -4.7409E-02 -1.2659E-02 -3.9923E-03 -1.1317E-03 -3.5059E-04 -1.0604E-04 S4 6.9257E-02 -1.7605E-02 1.2374E-03 -2.1949E-03 1.8899E-03 -6.7305E-04 5.0210E-04 S5 2.5493E-02 -2.0640E-03 2.8475E-03 -1.5492E-03 1.4631E-03 -6.4394E-04 3.8505E-04 S6 -6.4031E-02 1.8739E-03 -5.0921E-03 1.5941E-03 -1.7424E-04 2.5362E-04 3.3862E-04 S7 -2.1374E-01 2.7165E-02 -1.0448E-02 2.5264E-03 -9.5870E-04 1.0369E-04 1.0886E-04 S8 -2.9174E-01 4.3273E-02 -9.5676E-03 1.6527E-03 -1.0257E-03 -2.2481E-04 2.4728E-04 S9 1.4991E-01 -1.2976E-02 3.0993E-04 -1.2213E-03 1.9809E-04 -6.0449E-04 3.0892E-04 S10 2.2578E-02 3.7984E-02 -7.7226E-03 3.2508E-04 1.3716E-03 -8.2842E-04 5.0024E-04 S11 -7.7189E-02 -9.6670E-03 8.5982E-03 -3.4507E-03 3.3792E-03 -1.1552E-03 8.0995E-04 S12 -2.1276E-01 -6.1178E-03 2.2262E-03 -7.7889E-04 8.5914E-04 -1.4023E-05 1.6389E-04

[0112] Table 6-1

[0113] Face number A18 A20 A22 A24 A26 A28 A30 S1 1.6682E-05 6.5404E-06 5.2303E-06 2.0555E-07 -5.3914E-06 -2.1248E-06 5.1520E-07 S2 3.0411E-07 2.0067E-06 -4.2970E-06 1.4555E-06 -7.2380E-07 7.0451E-07 -1.7849E-07 S3 -2.7315E-05 -3.1241E-06 7.4096E-06 8.4405E-07 2.8467E-06 -6.8587E-07 1.8102E-06 S4 -1.4607E-04 1.3380E-04 -1.0796E-04 2.6739E-05 -9.8792E-06 2.3537E-06 -6.0418E-07 S5 -1.5150E-04 1.5380E-04 -8.6225E-05 2.3374E-05 -5.6139E-06 6.7319E-07 3.1104E-07 S6 5.7812E-05 1.4916E-04 -8.6545E-05 -2.3752E-05 -7.7783E-06 -1.9494E-06 -1.7500E-07 S7 -4.8805E-05 1.5933E-04 -4.5435E-05 -3.0412E-06 -1.7664E-06 7.2055E-07 2.1842E-07 S8 -2.7833E-04 3.0238E-04 -2.1471E-04 8.9488E-06 2.4306E-05 3.0450E-06 -1.2190E-06 S9 -3.2452E-04 2.7985E-04 -1.8855E-04 -7.6213E-06 1.9516E-05 6.5680E-07 -3.0013E-06 S10 -5.2437E-04 2.3966E-04 -2.0963E-04 2.8825E-05 -2.0545E-05 1.2011E-05 -8.4701E-06 S11 -5.9007E-04 2.7548E-04 -2.2487E-04 6.6702E-05 -2.2367E-05 1.5101E-05 -1.1394E-05 S12 -2.3781E-06 4.9760E-05 -7.4379E-07 1.2620E-05 -1.3066E-07 -4.9029E-06 -2.8793E-06

[0114] Table 6-2

[0115] Figure 6A The on-axis chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 6B 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 6C 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 6D The magnification chromatic aberration curve of the optical imaging system of Embodiment 3 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 6A to 6D It can be seen that the optical imaging system given in Example 3 can achieve good imaging quality.

[0116] Example 4

[0117] The following is for reference Figures 7 to 8D 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.

[0118] like Figure 7 As shown, the optical imaging system, along the reversing optical axis from the object side to the image side, sequentially includes: a first lens E1, a reflecting element P1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a filter E7. The first lens E1 and the reflecting element P1 are located in the first optical axis segment of the reversing optical axis, while the second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7 are located in the second optical axis segment of the reversing optical axis. More specifically, the reflecting surface of the reflecting element P1 is located at the junction of the first and second optical axis segments of the reversing optical axis.

[0119] In this embodiment, the first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The reflecting element P1 has an incident surface, a reflecting surface, and an exit surface. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. 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 sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. The optical imaging system has an imaging surface S15. Light from the object passes sequentially along the first optical axis segment through the first lens E1 to the reflecting element P1, is reflected by the reflecting element P1 to the second optical axis segment, and then passes sequentially along the second optical axis segment through the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the filter E7, and is finally imaged on the imaging surface S15.

[0120] Table 7 shows the basic parameters of the optical imaging system of Example 4, where the units for radius of curvature and thickness / distance 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, where each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0121]

[0122]

[0123] Table 7

[0124] Face number A4 A6 A8 A10 A12 A14 A16 S1 3.6533E-01 -3.7531E-03 2.8941E-03 -1.3883E-04 1.2719E-04 -5.1426E-05 2.8273E-05 S2 -5.4574E-02 -6.7513E-03 -3.3952E-05 -3.1107E-04 7.4829E-05 -6.0843E-05 3.0855E-05 S3 -2.1181E-01 -4.1581E-02 -9.4614E-03 -2.8880E-03 -7.7116E-04 -2.7622E-04 -7.8381E-05 S4 6.5931E-02 -1.4593E-02 2.3160E-03 -2.5421E-03 1.4397E-03 -6.7183E-04 4.1661E-04 S5 1.9107E-02 -2.8419E-03 1.7059E-03 -1.6454E-03 1.2597E-03 -5.4391E-04 3.9783E-04 S6 -5.1447E-02 5.1829E-03 -4.2191E-03 3.3008E-03 7.7451E-05 8.9563E-04 3.7893E-04 S7 -2.0973E-01 2.8392E-02 -7.5113E-03 5.0082E-03 -2.3778E-04 1.3336E-03 3.4156E-04 S8 -2.7345E-01 3.8315E-02 -5.5244E-03 2.7570E-03 -7.2509E-04 6.2575E-04 1.1705E-04 S9 1.4545E-01 -1.1875E-02 2.1876E-04 2.1742E-05 2.0216E-04 -3.3769E-05 2.0124E-04 S10 1.2009E-02 3.4005E-02 -8.2095E-03 7.9558E-04 8.6740E-04 -1.4165E-03 4.0097E-04 S11 -6.5093E-02 -9.7850E-03 8.1010E-03 -2.4802E-03 2.2204E-03 -1.8046E-03 5.1146E-04 S12 -1.6836E-01 -4.5653E-03 2.7504E-03 -5.4808E-04 3.9546E-04 -2.4157E-04 4.9501E-05

[0125] Table 8-1

[0126] Face number A18 A20 A22 A24 A26 A28 A30 S1 -1.3686E-05 1.0537E-05 -7.5022E-06 6.1075E-06 -3.8723E-06 2.0388E-06 -4.1610E-07 S2 -1.5948E-05 1.1844E-05 -8.3085E-06 6.7868E-06 -4.0736E-06 2.4947E-06 -1.3888E-06 S3 -2.6868E-05 -5.3931E-06 -1.2691E-06 -2.0001E-06 9.2552E-07 -1.0345E-06 8.4225E-07 S4 -1.8762E-04 1.3419E-04 -8.8403E-05 3.7259E-05 -1.7093E-05 3.1534E-06 -2.0374E-06 S5 -1.9781E-04 1.4459E-04 -1.0105E-04 4.3000E-05 -1.8649E-05 4.1341E-06 -1.3361E-06 S6 1.4312E-05 1.5230E-04 -5.1533E-05 1.5609E-05 -8.0643E-06 -4.9182E-06 -2.7227E-06 S7 -4.2407E-06 1.4260E-04 -8.2255E-05 6.0189E-06 -1.2840E-05 -5.5925E-06 -1.1833E-06 S8 -1.7970E-04 2.2505E-04 -1.1906E-04 1.5899E-05 -5.0804E-06 -7.3416E-07 -1.0499E-06 S9 -2.0908E-04 2.2395E-04 -1.1309E-04 1.0428E-05 -1.9479E-06 -1.0849E-06 3.4410E-07 S10 -3.5069E-04 2.6826E-04 -1.4267E-04 5.3183E-05 -1.9246E-05 1.0764E-05 -1.2775E-06 S11 -4.2275E-04 2.4961E-04 -1.3855E-04 6.2395E-05 -2.0616E-05 1.2704E-05 -1.9298E-06 S12 -2.4629E-05 1.3808E-05 -5.4062E-06 6.5581E-06 1.5546E-06 3.7089E-09 -2.4735E-07

[0127] Table 8-2

[0128] Figure 8A The on-axis chromatic aberration curve of the optical imaging system of Embodiment 4 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 8B 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 8C 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 8D The magnification chromatic aberration curve of the optical imaging system of Embodiment 4 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 8A to 8D It can be seen that the optical imaging system given in Example 4 can achieve good imaging quality.

[0129] Example 5

[0130] The following is for reference Figures 9 to 10D 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.

[0131] like Figure 9 As shown, the optical imaging system, along the reversing optical axis from the object side to the image side, sequentially includes: a first lens E1, a reflecting element P1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, and a filter E7. The first lens E1 and the reflecting element P1 are located in the first optical axis segment of the reversing optical axis, while the second lens E2, third lens E3, fourth lens E4, fifth lens E5, sixth lens E6, and filter E7 are located in the second optical axis segment of the reversing optical axis. More specifically, the reflecting surface of the reflecting element P1 is located at the junction of the first and second optical axis segments of the reversing optical axis.

[0132] In this embodiment, the first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The reflecting element P1 has an incident surface, a reflecting surface, and an exit surface. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being concave and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. 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 sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. The optical imaging system has an imaging surface S15. Light from the object passes sequentially along the first optical axis segment through the first lens E1 to the reflecting element P1, is reflected by the reflecting element P1 to the second optical axis segment, and then passes sequentially along the second optical axis segment through the second lens E2, the third lens E3, the fourth lens E4, the fifth lens E5, the sixth lens E6 and the filter E7, and is finally imaged on the imaging surface S15.

[0133] Table 9 shows the basic parameters of the optical imaging system of Example 5, where the units for radius of curvature and thickness / distance 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, where each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0134]

[0135]

[0136] Table 9

[0137] Face number A4 A6 A8 A10 A12 A14 A16 S1 4.6071E-01 -9.7471E-03 1.3200E-03 -1.9457E-04 -3.0406E-05 6.4643E-05 -2.3995E-05 S2 -8.2113E-02 -1.5247E-02 -3.4760E-03 -3.9851E-04 -1.6542E-04 6.9716E-05 -4.3737E-05 S3 -2.5402E-01 -5.4410E-02 -1.5160E-02 -5.1693E-03 -1.6917E-03 -5.8304E-04 -1.8426E-04 S4 7.4625E-02 -1.6650E-02 2.1608E-03 -1.9377E-03 1.2833E-03 -6.5800E-04 3.8132E-04 S5 1.2942E-02 -6.2257E-03 2.8387E-03 1.9769E-05 1.3547E-03 -9.2987E-04 3.0220E-04 S6 -3.4320E-02 6.2900E-03 -7.3030E-03 3.1187E-03 3.7523E-04 2.7198E-04 2.2522E-04 S7 -2.2173E-01 2.7725E-02 -7.3020E-03 2.4447E-03 -6.8898E-04 3.8743E-04 6.9671E-05 S8 -2.4903E-01 2.2349E-02 3.3461E-04 1.6141E-03 -5.6626E-04 3.4166E-04 -2.1132E-05 S9 1.2108E-01 -3.3779E-03 -2.2504E-03 -1.4589E-03 1.0323E-03 -7.7265E-04 3.0794E-04 S10 2.7216E-02 2.4119E-02 -3.0878E-03 -3.7397E-03 2.7201E-03 -1.5764E-03 3.1442E-04 S11 -7.0830E-02 4.2710E-03 2.1326E-03 -1.8564E-03 2.0111E-03 -6.5938E-04 1.0034E-04 S12 -2.2449E-01 -4.3415E-03 -2.8703E-03 -2.1994E-04 2.0607E-04 -3.8721E-05 2.2028E-05

[0138] Table 10-1

[0139] Face number A18 A20 A22 A24 A26 A28 A30 S1 1.7119E-05 -1.0370E-05 4.4107E-06 -6.1492E-07 6.6406E-06 2.2932E-07 -2.6823E-06 S2 2.0968E-05 -1.8050E-05 9.2927E-06 -3.8795E-06 6.1347E-06 -5.7526E-06 -1.8054E-06 S3 -1.6978E-05 1.8685E-05 3.3998E-05 2.2565E-05 2.1081E-05 8.3499E-06 6.3672E-06 S4 -1.7242E-04 -4.9186E-06 -7.5426E-05 -2.5289E-05 -2.3057E-05 -8.8818E-06 -5.1591E-07 S5 -4.4892E-04 4.1775E-05 2.1775E-05 1.1044E-04 6.1043E-05 4.1941E-05 1.2946E-05 S6 -7.6706E-05 1.0041E-05 -3.3086E-05 1.0843E-05 -1.3815E-05 1.8556E-06 1.0385E-05 S7 -4.7956E-05 6.0918E-05 -2.6639E-05 3.2551E-05 1.9994E-06 -4.9967E-06 7.9811E-06 S8 -1.6165E-04 1.1430E-04 -1.0491E-04 1.7839E-05 -3.1503E-05 -6.4092E-06 1.4565E-05 S9 -2.2578E-04 2.1345E-04 -7.8951E-05 1.5072E-05 -1.6595E-05 -1.8492E-05 1.7264E-05 S10 -2.2888E-04 2.0492E-04 -3.7701E-05 1.0647E-05 -3.7083E-06 -2.2797E-05 1.0347E-05 S11 -1.3542E-04 4.9420E-05 1.5666E-06 2.2712E-06 1.0464E-05 -1.5200E-05 4.1601E-06 S12 -1.8235E-05 1.1517E-05 -3.8204E-06 3.9585E-06 -8.4141E-07 -1.1756E-06 4.1700E-07

[0140] Table 10-2

[0141] Figure 10A The on-axis chromatic aberration curve of the optical imaging system of Embodiment 5 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 10B 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 10C 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 10D The magnification chromatic aberration curve of the optical imaging system of Embodiment 5 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 10A to 10D It can be seen that the optical imaging system given in Example 5 can achieve good imaging quality.

[0142] In summary, Examples 1 to 5 satisfy the relationships shown in Table 11.

[0143] Conditional / Example 1 2 3 4 5 TTL(mm) 29.00 26.68 27.28 27.45 29.00 ImgH(mm) 4.35 4.35 4.10 4.35 4.35 Semi-FOV (°) 11.9 12.7 12.0 12.6 12.8 Fno 2.6 2.6 2.6 2.6 2.6 f(mm) 20.07 18.74 18.68 18.90 18.50 SAG11 (mm) 1.33 1.03 1.13 1.06 1.21 SAG12 (mm) 0.93 0.76 0.82 0.76 0.84 SAG21 (mm) 0.93 0.93 0.93 0.93 0.93 SAG22 (mm) -0.45 -0.37 -0.43 -0.31 -0.46 f234(mm) -35.92 -32.94 -12.99 -13.46 -12.18 f34(mm) -3.06 -3.15 -13.23 -13.52 -11.74 R3 / R4 -0.72 -0.59 -0.73 -0.53 -0.91 f / f4 -3.03 -2.66 -2.58 -1.57 -1.81 CT2 / CT1 1.63 2.27 1.95 1.87 1.58 T12 / ∑AT 0.88 0.81 0.92 0.92 0.89 SL / EPD 2.10 2.16 2.22 2.21 2.34 f4 / f6 -0.61 -0.67 -0.74 -1.25 -1.25 f1 / f 3.30 3.85 3.59 3.52 3.66 f2 / f34 -1.98 -2.05 -0.46 -0.50 -0.47 R5×R6 / f234(mm) 2.43 3.01 6.24 4.43 3.02 T45 / T34 0.30 0.06 0.50 0.71 1.06 SAG11 / SAG21 1.43 1.11 1.22 1.15 1.30 SAG12 / SAG22 -2.07 -2.06 -1.91 -2.49 -1.82 (CT2-CT3) / T23 5.75 8.65 6.01 5.82 5.16 T45 / CT5 0.40 0.13 0.15 0.21 0.56

[0144] Table 11

[0145] This application also provides an electronic device, which can be a mobile electronic device such as a digital camera or a mobile phone. The electronic device is equipped with the optical imaging system described above and an imaging element for converting the optical image formed by the optical imaging system into an electrical signal. Its electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS).

[0146] Figure 11 A schematic diagram of an electronic device according to an exemplary embodiment of this application is shown. The electronic device is a mobile phone, which is equipped with the optical imaging system described above.

[0147] 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, comprising a first element group and a second element group arranged sequentially along the optical axis from the object side to the image side, characterized in that, The first element group includes a first lens having positive optical power and a reflective element; The second element group includes a second lens with positive optical power, a third lens with negative optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power. in, The optical axis includes a first optical axis segment and a second optical axis segment, and the first optical axis segment is perpendicular to the second optical axis segment. The first element group is located in the first optical axis segment, and the second element group is located in the second optical axis segment. The reflective element has an incident surface, a reflecting surface, and an exit surface, and the reflecting surface of the reflective element is located at the connection between the first optical axis segment and the second optical axis segment; The reflective element is configured such that light emitted from the first lens enters the reflective element through the incident surface along the direction of the first optical axis segment, and after being reflected by the reflective surface, exits through the exit surface along the direction of the second optical axis segment into the second lens; The optical imaging system has six lenses with optical power. Both the object-side surfaces of the first lens and the fifth lens are convex, and both image-side surfaces are concave. Both the object-side and image-side surfaces of the second lens are convex. Both the object-side and image-side surfaces of the third lens are concave. The image-side surface of the fourth lens is concave, and the object-side surface of the sixth lens is convex. The maximum field of view (SemiFOV) of the optical imaging system satisfies: 11.9° ≤ SemiFOV ≤ 12.8°; The center thickness CT1 of the first lens on the optical axis and the center thickness CT2 of the second lens on the optical axis satisfy: 1.58≤CT2 / CT1≤2.27; The distance T23 between the second lens and the third lens on the optical axis, the center thickness CT2 of the second lens on the optical axis and the center thickness CT3 of the third lens on the optical axis satisfy: 5.16≤(CT2-CT3) / T23≤8.

65.

2. The optical imaging system according to claim 1, wherein, 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: -0.91≤R3 / R4≤-0.

53.

3. The optical imaging system according to claim 1, wherein, The effective focal length f4 of the fourth lens and the effective focal length f of the optical imaging system satisfy the following condition: -3.03≤f / f4≤-1.

57.

4. The optical imaging system according to claim 1, wherein, The distance T12 between the image side of the first lens and the object side of the second lens on the optical axis and the sum of the distances ∑AT between any two adjacent lenses from the first lens to the fifth lens on the optical axis satisfy: 0.81≤T12 / ∑AT≤0.

92.

5. The optical imaging system according to claim 1, wherein, The optical imaging system further includes an aperture stop, and the on-axis distance SL from the aperture stop to the imaging surface of the optical imaging system and the entrance pupil diameter EPD of the optical imaging system satisfy the following condition: 2.10≤SL / EPD≤2.

34.

6. The optical imaging system according to claim 1, wherein, The effective focal length f4 of the fourth lens and the effective focal length f6 of the sixth lens satisfy the condition: -1.25≤f4 / f6≤-0.

61.

7. The optical imaging system according to claim 1, wherein, The effective focal length f1 of the first lens and the effective focal length f of the optical imaging system satisfy the condition: 3.30≤f1 / f≤3.

85.

8. The optical imaging system according to claim 1, wherein, At least two of the first to fifth lenses have a center thickness greater than 1 mm on the optical axis.

9. The optical imaging system according to claim 1, wherein, The effective focal length f2 of the second lens and the combined focal length f34 of the third and fourth lenses satisfy: -2.05≤f2 / f34≤-0.

46.

10. The optical imaging system according to claim 1, wherein, The radius of curvature R5 of the object side of the third lens, the radius of curvature R6 of the image side of the third lens, and the combined focal length f234 of the second lens, the third lens, and the fourth lens satisfy: 2.43mm≤R5×R6 / f234≤6.24mm.

11. The optical imaging system according to claim 1, wherein, The distance T34 between the third lens and the fourth lens on the optical axis and the distance T45 between the fourth lens and the fifth lens on the optical axis satisfy the following condition: 0.06 ≤ T45 / T34 ≤ 1.

06.

12. The optical imaging system according to claim 1, wherein, The center thickness CT5 of the fifth lens on the optical axis and the spacing T45 between the fourth and fifth lenses on the optical axis satisfy the following condition: 0.13≤T45 / CT5≤0.

56.

13. The optical imaging system according to claim 1, wherein, The axial distance SAG12 between the intersection of the image-side surface of the first lens and the first optical axis segment and the vertex of the effective radius of the image-side surface of the first lens and the axial distance SAG22 between the intersection of the image-side surface of the second lens and the second optical axis segment and the vertex of the effective radius of the image-side surface of the second lens satisfy: -2.49≤SAG12 / SAG22≤-1.

82.

14. The optical imaging system according to claim 1, wherein, The axial distance SAG11 between the intersection of the object side surface of the first lens and the first optical axis and the vertex of the effective radius of the object side surface of the first lens and the axial distance SAG21 between the intersection of the object side surface of the second lens and the second optical axis and the vertex of the effective radius of the object side surface of the second lens satisfy: 1.11≤SAG11 / SAG21≤1.

43.

15. An electronic device, characterized in that, It includes an optical imaging system according to any one of claims 1-14 and an imaging element for converting an optical image formed by the optical imaging system into an electrical signal.

Images