Camera modules and electronic devices

Abstract

This application discloses a camera module and an electronic device. The camera module includes: a lens group, a first reflector, a second reflector, and a photosensitive element arranged sequentially along an optical axis. The reflective surfaces of the first reflector and the second reflector are arranged far apart from each other. A light-transmitting area is provided at the center of the second reflector. After light passes through the lens group and is incident on the second reflector, it is reflected by the second reflector to the first reflector, and after being reflected by the first reflector, it is incident on the photosensitive element from the light-transmitting area. The lens group includes a first lens, which has positive optical power.

Description

Technical Field

[0001] This application belongs to the field of photography technology, specifically relating to a camera module and electronic device. Background Technology

[0002] With the popularization of photography technology, users have placed higher demands on the versatility of lens functions, ease of operation, and artistic imaging effects. Among related technologies, telephoto lenses are widely used in professional portrait and landscape photography, and their core functions have seen significant development. With the increasing demand for outdoor photography and travel shooting, users have placed higher demands on the portability and lightweight nature of lenses. Catadioptric lenses utilize a mirror group to fold the light path, enabling them to achieve super-long focal lengths with a shorter optical travel.

[0003] However, current catadioptric lenses suffer from technical defects such as insufficient aberration correction and low light transmission, making it difficult to achieve high-quality imaging. Summary of the Invention

[0004] This application aims to provide a camera module and electronic device that solves the technical defects of current catadioptric optical lenses, such as insufficient aberration correction and low light transmission, which make it difficult to achieve high-quality imaging.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a camera module, comprising: A lens group, a first reflecting mirror, a second reflecting mirror, and a photosensitive element are arranged sequentially along the optical axis. The reflecting surfaces of the first reflecting mirror and the second reflecting mirror are arranged far apart from each other. A light-transmitting area is provided at the center of the second reflecting mirror. After light passes through the lens group and is incident on the second reflecting mirror, it is reflected by the second reflecting mirror to the first reflecting mirror, and after being reflected by the first reflecting mirror, it is incident on the photosensitive element from the light-transmitting area. The lens group includes a first lens having positive optical power.

[0006] Secondly, embodiments of this application provide an electronic device, including a device body and a camera module as described above; The camera module is integrated into the device body, or the camera module is detachably connected to the device body.

[0007] In the embodiments of this application, light rays pass through the lens group and are incident on the second reflector. The light is then reflected by the second reflector back to the first reflector, and after being reflected again by the first reflector, it travels from the light-transmitting area to the photosensitive element. The first and second reflectors can be used in conjunction to fold the light path, achieving an ultra-long focal length with a shorter optical path. Since the lens group includes a first lens with positive optical power, aberrations can be corrected in advance using the first lens. Furthermore, the first lens can converge the light, allowing more light to reach the second reflector, thereby increasing the light transmission and achieving high-quality imaging. The camera module in this embodiment achieves an ultra-long focal length with a shorter optical path while also providing high-quality imaging.

[0008] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0009] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a camera module according to an embodiment of this application; Figure 2 It is the on-axis chromatic aberration curve of the camera module in Implementation Method 1; Figure 3 It is the astigmatism curve of the camera module in Implementation Method 1; Figure 4 It is the distortion curve of the camera module in Implementation Method 1; Figure 5 This is the magnification color difference curve of the camera module in Implementation Method 1; Figure 6 This is a schematic diagram of a camera module according to an embodiment of this application; Figure 7 It is the on-axis chromatic aberration curve of the camera module in implementation method 2; Figure 8 It is the astigmatism curve of the camera module in implementation method 2; Figure 9 This is the distortion curve of the camera module in Implementation Method 2; Figure 10 This is the magnification color difference curve of the camera module in Implementation Method 2.

[0010] Figure label: 10. Lens group; 11. First lens; 12. Second lens; 20. First reflecting mirror; 30. Second reflecting mirror; 31. Light-transmitting area; 41. Third lens; 42. Fourth lens; 50. Photosensitive element. Detailed Implementation

[0011] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0012] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0014] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0015] The following is combined with Figures 1-10 This application describes a camera module and an electronic device according to embodiments of the present application.

[0016] like Figure 1As shown, according to some embodiments of the present application, the camera module may include a housing and an optical system. The optical system is the optical path portion of the camera module, used to achieve imaging. The housing is the mechanical structure portion of the camera module, which can support and mount the components in the optical system, and the housing can also protect the components in the optical system.

[0017] The optical system includes a lens group 10, a first reflecting mirror 20, a second reflecting mirror 30, and a photosensitive element 50, which are arranged sequentially along the optical axis. Figure 1 As shown, the optical axis S0 represents the central reference axis (a geometric straight line) of the entire optical system, which is the common center line connecting the lens group 10, the first reflecting mirror 20, the second reflecting mirror 30, and the photosensitive element 50.

[0018] In some optional embodiments, the reflective surfaces of the first reflector 20 and the second reflector 30 can be positioned far apart from each other, and a light-transmitting area 31 is provided at the center of the second reflector 30; after light passes through the lens group 10 and is incident on the second reflector 30, it is reflected by the second reflector 30 to the first reflector 20, and after being reflected by the first reflector 20, it is incident on the photosensitive element 50 from the light-transmitting area 31. The lens group 10 includes a first lens 11, which has positive optical power.

[0019] In the embodiments of this application, light rays pass through the lens group 10 and are incident on the second reflecting mirror 30. The light is then reflected by the second reflecting mirror 30 to the first reflecting mirror 20, and after further reflection by the first reflecting mirror 20, it travels from the light-transmitting area 31 to the photosensitive element 50. The first reflecting mirror 20 and the second reflecting mirror 30 can be used to fold the light path, achieving an ultra-long focal length with a shorter optical path. Since the lens group 10 includes a first lens 11 with positive optical power, aberrations can be corrected in advance using the first lens 11. Furthermore, the first lens 11 can converge light rays, allowing more light to reach the second reflecting mirror 30, thereby increasing the light transmission and achieving high-quality imaging. The camera module in the embodiments of this application achieves an ultra-long focal length with a shorter optical path while also providing high-quality imaging.

[0020] In some embodiments, the first reflector 20 and the second reflector 30 can be combined to form a refraction system. Both the first reflector 20 and the second reflector 30 are capable of refracting and reflecting light, and their reflective surfaces are both used to reflect light. The reflective surfaces of the first reflector 20 and the second reflector 30 are spaced far apart; specifically, the reflective surface of the first reflector 20 is located on the side of the first reflector 20 furthest from the second reflector 30, and the reflective surface of the second reflector 30 is located on the side of the second reflector 30 furthest from the first reflector 20. Both the reflective surfaces of the first reflector 20 and the second reflector 30 can be coated with a reflective film to ensure their ability to reflect light.

[0021] In some embodiments, a light-transmitting area 31 is provided at the center of the second reflector 30, which is used to transmit light. A reflective film can be deposited on the outer periphery of the center of the second reflector 30 to achieve the effect that the outer periphery of the second reflector 30 reflects light, while the central portion transmits light reflected by the first reflector 20. Alternatively, a hole can be cut in the center of the second reflector 30 to form the light-transmitting area 31.

[0022] In some embodiments, the first reflector 20 is disposed between the lens group 10 and the second reflector 30. The outer diameter of the first reflector 20 may be smaller than the outer diameter of the lens group 10 and the outer diameter of the second reflector 30, respectively, so that light can first travel from the lens group 10 to the second reflector 30.

[0023] In some embodiments, a light-transmitting area 31 may be formed at the center of the second reflector 30. The center line of the light-transmitting area 31 is located on the optical axis. After being reflected by the first reflector 20, light can pass through the light-transmitting area 31 and be directed to the photosensitive element 50. The shape of the light-transmitting area 31 may be circular or polygonal, etc. The shape and specific size of the light-transmitting area 31 can be set according to actual needs, and are not limited in this embodiment.

[0024] In some embodiments, the lens group 10 is disposed at the front end of the optical axis, which can process the light first and transmit the processed light to the second reflector 30. The lens group 10 includes a first lens 11, which has positive optical power, allowing the first lens 11 to correct aberrations in advance, and the first lens 11 can converge the light, which is beneficial to transmitting more light to the second reflector 30, thereby increasing the amount of light directed toward the photosensitive element 50.

[0025] In some embodiments, the photosensitive element 50 can be located at the end of the optical axis to receive light reflected by the lens group 10, the second reflecting mirror 30, and the third reflecting mirror. The photosensitive element 50 is the "electronic film" in the camera module that converts light into electrical signals and is the core of imaging. When light reaches the photosensitive element 50, the countless pixels on the photosensitive element 50 receive the light, and light of different intensities is converted into different electrical signals, which are then stitched together by the processor to form a photo / video.

[0026] Traditional Cassegrain catadioptric lenses have a first reflecting mirror 20 and a second reflecting mirror 30. Compared with traditional Cassegrain catadioptric lenses, the camera module in this embodiment adds a lens group 10 at the front end of the optical axis, which can correct aberrations in advance, increase light transmission, and thus achieve high-quality shooting.

[0027] In some alternative embodiments, the lens group 10 further includes a second lens 12 having negative optical power, and the second lens 12 is disposed between the first lens 11 and the first reflecting mirror 20.

[0028] In this embodiment, the first lens 11 has positive optical power and the second lens 12 has negative optical power, so that the first lens 11 and the second lens 12 cooperate with each other, and the positive and negative optical powers are matched to form different combinations of optical power. This can compensate for the residual chromatic aberration and secondary spectral deviation caused by the central obstruction of the catadioptric system in advance, and better eliminate chromatic aberration to further improve the imaging quality.

[0029] In some embodiments, the first lens 11 can be located at the foremost end of the optical axis, so that the first lens 11 can first converge the light to ensure that a large amount of light is directed toward the photosensitive element 50.

[0030] Of course, in some embodiments, the second lens 12 can also be positioned on the side of the first lens 11 away from the first reflecting mirror 20 through reasonable design, so that the second lens 12 is positioned at the foremost end of the optical axis.

[0031] In some alternative embodiments, the Abbe number of the first lens 11 is greater than the Abbe number of the second lens 12.

[0032] In this embodiment, since the Abbe number of the first lens 11 is greater than that of the second lens 12, high-dispersion and low-dispersion optical materials can be paired to enhance the achromatic aberration capability of the lens group 10, which is beneficial to further improve the imaging quality.

[0033] In some alternative embodiments, the Abbe number of the first lens 11 is vd1, and vd1 satisfies: 50 < vd1 < 70; the Abbe number of the second lens 12 is vd2, and vd2 satisfies: 20 < vd2 < 40.

[0034] In this embodiment, since 50 < vd1 < 70 and 20 < vd2 < 40, it is beneficial to ensure that the Abbe number of the first lens 11 is greater than the Abbe number of the second lens 12, and the first lens 11 and the second lens 12 cooperate to achieve high and low color matching.

[0035] For example, the Abbe number vd1 of the first lens 11 can be 53.6, and the Abbe number vd2 of the second lens 12 can be 28.3. Alternatively, the Abbe number vd1 of the first lens 11 can be 60, and the Abbe number vd2 of the second lens 12 can be 30.

[0036] In some alternative embodiments, the refractive index of the first lens 11 is less than that of the second lens 12.

[0037] In this embodiment, since the refractive index of the first lens 11 is less than that of the second lens 12, a differentiated combination of high and low refractive indices can be used to optimize the light deflection degree of the optical surface of the lens group 10, which is beneficial to further improve the imaging quality.

[0038] In some alternative embodiments, the refractive index of the first lens 11 is nd1, which satisfies: 1.4 < nd1 < 1.6; the refractive index of the second lens 12 is nd2, which satisfies: 1.65 < nd2 < 1.85.

[0039] In this embodiment, since 1.4 < nd1 < 1.6 and 1.65 < nd2 < 1.85, it is convenient to ensure that the refractive index of the first lens 11 is less than that of the second lens 12, so that the first lens 11 and the second lens 12 work together to achieve the difference between high and low refractive indices.

[0040] For example, the refractive index of the first lens 11 can be 1.5176, and the refractive index of the second lens 12 can be 1.74. Alternatively, the refractive index of the first lens 11 can be 1.5, and the refractive index of the second lens 12 can be 1.75.

[0041] In some embodiments, the Abbe number vd1 of the first lens 11 is greater than the Abbe number vd2 of the second lens 12, the refractive index nd1 of the first lens 11 is less than the refractive index nd2 of the second lens 12, and the parameters are controlled such that 50 < vd1 < 70, 20 < vd2 < 40, 1.4 < nd1 < 1.6, and 1.65 < nd2 < 1.85. This allows the first lens 11 and the second lens 12 to work together to reasonably share the optical power, suppress off-axis aberrations such as spherical aberration, coma, and field curvature, and significantly improve the imaging quality of the catadioptric optical system.

[0042] In some alternative embodiments, the surfaces of the first lens 11 and the second lens 12 are bonded together, which helps to shorten the gap between the first lens 11 and the second lens 12, and helps to shorten the size of the camera module in the optical axis direction, thereby achieving miniaturization of the camera module. Furthermore, the bonding of the first lens 11 and the second lens 12 can better eliminate chromatic aberration and further improve the imaging quality.

[0043] In some embodiments, the first lens 11 and the second lens 12 can be bonded together by adhesive bonding, or other methods (such as fixing by other structural limiting clamps) can be used to achieve bonding between the two. This application does not limit this method. Regardless of the method used, it is necessary to ensure the light transmission requirements of the first lens 11 and the second lens 12, effectively ensuring that light can pass through the first lens 11 and the second lens 12 in sequence.

[0044] In some alternative embodiments, the photosensitive element 50 has an imaging surface for receiving light, and the effective focal length of the camera module is f1; along the optical axis, the axial distance from a point on the object side of the first lens 11 located on the optical axis to the imaging surface is L; when f1 ≥ 200 mm, the following condition is satisfied: 2.3 < f1 / L < 2.8.

[0045] In this embodiment, 2.3 < f1 / L < 2.8, which allows the camera module to achieve a telephoto lens while maintaining a small axial dimension. The camera module can utilize the folding advantage of the reflective optical path to achieve a telephoto effect with a short total axial length, thus overcoming the shortcomings of traditional camera modules, such as long axial dimensions and poor portability. This allows the camera module in this embodiment to achieve the advantages of small size and easy portability.

[0046] In some embodiments, the imaging surface is the target surface of the photosensitive element 50 that receives light. It is the plane in the camera module that projects and focuses the external scene to form a clear real image, and it is also the position where the image is finally received. Along the optical axis, the axial distance from a point on the object side of the first lens 11 located on the optical axis to the imaging surface is L. The larger L is, the longer the axial dimension of the corresponding camera module in the optical axis direction; the smaller L is, the smaller the axial dimension of the corresponding camera module in the optical axis direction.

[0047] In some embodiments, f1 represents the effective focal length of the camera module, in mm, and is an inherent parameter of the optical design. The effective focal length refers to the distance from the principal plane to the focal point when parallel incident light converges to the focal plane after passing through the camera module. When f1 ≥ 200mm, the camera module can achieve telephoto shooting. Since 2.3 < f1 / L < 2.8, even if f1 is designed to be large, L can still be small, allowing the camera module to achieve telephoto shooting while maintaining a small overall axial length. This contributes to the advantages of a small size and easy portability.

[0048] For example, by extending the focal length of the camera module to 242mm, the axial dimension of the camera module can be controlled to be smaller, so that the size of the camera module can be comparable to that of the main camera in the focal length range of 23mm~35mm, which is smaller.

[0049] In some optional embodiments, the effective focal length of the camera module is f1, the entrance pupil diameter of the camera module is D1, and the relationship between D1 and f1 satisfies: 4.0 < f1 / D1 < 5.0.

[0050] In this embodiment, 4.0 < f1 / D1 < 5.0, which enables the camera module to achieve a large aperture design, improving light transmission and low-light imaging capabilities.

[0051] In some embodiments, the entrance pupil is the image formed by the aperture stop of the camera module on the object side (front end) of the system, representing the maximum effective light-gathering cross-section that allows light to enter the system. The entrance pupil diameter represents the diameter of this circular light-gathering cross-section, which can be understood as the maximum aperture that the lens truly "collects" light from. f1 / D1 can represent the aperture of the camera module; 4.0 < f1 / D1 < 5.0 allows for a large aperture design, far superior to the small aperture specifications above f#6.0 of traditional Cassegrain-type catadioptric lenses.

[0052] For example, the aperture of the camera module can reach 4.9, 4.8, 4.6, or 4.5. Alternatively, the aperture of the camera module can reach below 4.5, such as 4.4, 4.3, or 4.2.

[0053] In some alternative embodiments, the photosensitive element 50 has an imaging surface for receiving light, the diagonal length of which is H; the axial distance L from a point on the object side of the first lens 11 located on the optical axis to the imaging surface; the relationship between H and L satisfies: 0.4 < H / L < 0.5.

[0054] In the embodiments of this application, 0.4 < H / L < 0.5. When H is designed to be larger, L can be kept at a smaller level, so that the camera module can achieve a balance between the large target surface imaging specifications and the short axial total length, which improves the space utilization of the camera module and is conducive to the camera module achieving the advantages of small size and lightweight structure.

[0055] In some embodiments, the diagonal length of the imaging plane can directly define the image plane size; the larger H is, the larger the imaging plane is, and the smaller H is, the smaller the imaging plane is.

[0056] In some embodiments, designing a larger H enables large target area imaging, while designing a smaller L results in a smaller axial dimension of the camera module, which is beneficial for miniaturization. By controlling 0.4 < H / L < 0.5, the design of H and L can be comprehensively considered to balance and optimize the large target area imaging specifications and the short axial length, allowing the camera module to achieve a relatively large target area imaging specifications while having a short axial length.

[0057] In some embodiments, the photosensitive element 50 has an imaging surface for receiving light, and the diagonal length of the imaging surface is H; the effective focal length of the camera module is f1, and 20 degrees ≤ f1 / H ≤ 22 degrees, so that the field of view of the camera module can reach 20-22 degrees, enabling the camera module to achieve a large field of view.

[0058] In some alternative embodiments, the outer diameter of the first lens 11 is D2; the photosensitive element 50 has an imaging surface that receives light, and the axial distance L from a point on the object side of the first lens 11 located on the optical axis to the imaging surface is: 0.5 < D2 / L < 1.

[0059] In this embodiment, 0.5 < D2 / L < 1, which can reasonably control the ratio of the aperture of the camera module to the overall length of the camera module, so as to achieve a compact and lightweight camera module structure and realize miniaturized integrated mounting.

[0060] In some embodiments, the first lens 11 is the lens with the largest outer diameter in the camera module, that is, the outer diameter of the first lens 11 is larger than the outer diameter of the first reflector 20 and the second reflector 30, respectively, and the outer diameter D2 of the first lens 11 determines the maximum aperture of the camera module.

[0061] In some embodiments, the effective focal length of the camera module is f1, and the focal length of the first reflecting mirror 20 is f2; the relationship between f1 and f2 satisfies: 0.3 < |f2 / f1| < 0.5.

[0062] In the embodiments of this application, controlling 0.3 < |f2 / f1| < 0.5 can constrain the front-end light-gathering capability of the camera module, enabling the camera module to match the telephoto folding optical path and the large aperture light-passing design, and balance the imaging quality of on-axis aberrations and off-axis fields of view.

[0063] In some embodiments, the axis represents the object point, image point, or imaging area located on the optical axis, corresponding to the center position of the image. The corresponding off-axis represents the area deviating from the optical axis (the edge of the image).

[0064] In some alternative embodiments, the object-side surface of the first lens 11 is convex, and the image-side surface of the first lens 11 is concave; the object-side surface of the second lens 12 is convex, and the image-side surface of the second lens 12 is concave; the object-side surface of the first reflecting mirror 20 is concave, and the image-side surface of the first reflecting mirror 20 is convex; the object-side surface of the second reflecting mirror 30 is concave, and the image-side surface of the second reflecting mirror 30 is convex.

[0065] In this embodiment, the object-side surface of the first lens 11 is convex, and the image-side surface is concave. This surface design of the first lens 11 ensures it has positive optical power. Similarly, the object-side surface of the second lens 12 is convex, and the image-side surface is concave. This surface design of the second lens 12 ensures it has negative optical power. The object-side surface of the first reflecting mirror 20 is concave, and the image-side surface is convex. This surface design of the first reflecting mirror 20 ensures the reliability of its reflection. Likewise, the object-side surface of the second reflecting mirror 30 is concave, and the image-side surface is convex. This surface design of the second reflecting mirror 30 ensures the reliability of its reflection.

[0066] Specifically, the object side and image side of the first lens 11 are both bent towards the image side (the side where the photosensitive element is located), the object side and image side of the second lens 12 are both bent towards the image side, the object side and image side of the first reflector 20 are both bent towards the object side (the side where the object is being photographed), and the object side and image side of the second reflector 30 are both bent towards the object side (the side where the object is being photographed).

[0067] In some embodiments, the camera module further includes a third lens 41 and a fourth lens 42, which are sequentially disposed between the second reflector 30 and the photosensitive element 50 for refracting light; the object side of the third lens 41 is concave and the image side of the third lens 41 is concave; the object side of the fourth lens 42 is convex and the image side of the fourth lens 42 is concave.

[0068] In this embodiment, the third lens 41 and the fourth lens 42 are sequentially disposed between the second reflecting mirror 30 and the photosensitive element 50, which can further refract light to eliminate defocus, make the image clearer, and further improve the image quality. Moreover, the object-side surface of the third lens 41 is concave, and the image-side surface of the third lens 41 is concave; the object-side surface of the fourth lens 42 is convex, and the image-side surface of the fourth lens 42 is concave. By designing the surface shapes of the third lens 41 and the fourth lens 42, a better defocus elimination effect can be achieved.

[0069] In some embodiments, the materials of the first lens 11, the second lens 12, the first reflector 20, the second reflector 30, the third lens 41, and the fourth lens 42 may be the same or different, and the specific materials may be resin or glass. In this embodiment, the surface types of the first lens 11, the second lens 12, the first reflector 20, and the second reflector 30 are spherical, while the surface types of the third lens 41 and the fourth lens 42 are aspherical. In other cases, the surface types of the first lens 11, the second lens 12, the first reflector 20, and the second reflector 30 may be designed to be aspherical, or the surface types of the third lens 41 and the fourth lens 42 may be designed to be spherical.

[0070] In some embodiments, the first formula for aspherical surfaces is: (1) Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; 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); k is the conic coefficient; Ai is the correction coefficient for the i-th order (ith order) of the aspherical surface.

[0071] like Figure 1 This diagram illustrates the structure of a camera module according to Embodiment 1. Along the optical axis, the camera module sequentially includes a cemented first lens 11 and a second lens 12, a first reflector 20, a second reflector 30, and cemented third and fourth lenses 41 and 42. Table 1 illustrates the surface type, radius of curvature, thickness, material, and conic coefficient of each lens in the camera module of Embodiment 1. The units for radius of curvature and thickness are millimeters (mm).

[0072] Table 1,

[0073] As shown in Table 1, S1 to S13 are the surfaces through which light passes after passing through the first lens 11, the second lens 12, the second reflecting mirror 30, the first reflecting mirror 20, the third lens 41, and the fourth lens 42 in sequence. For example, S1 represents the object side of the first lens 11. Since the first lens 11 and the second lens 12 are cemented together, S2 represents the image side of the first lens 11 and the object side of the second lens 12. S3 represents the image side of the second lens 12. S4, S5, and S9 represent the object side of the second mirror 30. STO represents the aperture plane, which is the reflection area of ​​the image side of the second mirror 30. S6 and S8 represent the image side of the second mirror 30. S7 represents the object side of the first mirror 20. S10 represents the light-transmitting area 31 of the image side of the second mirror 30. S11 represents the object side of the third lens 41. Since the third lens 41 and the fourth lens 42 are cemented together, S12 represents the image side of the third lens 41 and the object side of the fourth lens 42. S13 represents the image side of the fourth lens 42.

[0074] As shown in Table 1, the object-side surface of the first lens 11 is spherical with a radius of curvature of 93.3784; the thickness of the first lens 11 (distance from surface S1 to surface S2) is 0.6030 mm, the refractive index of the first lens 11 is 1.5176, and the Abbe number of the first lens 11 is 53.6. Similarly, the image-side surface of the fourth lens 42 is aspherical with a radius of curvature of 15.4991; the thickness of the fourth lens 42 (distance from surface S12 to surface S13) is 2.9759 mm, the distance from surface S13 to the imaging plane is 19.5980 mm, the refractive index of the fourth lens 42 is 1.74, and the Abbe number of the fourth lens 42 is 28.3. The thickness from surface S10 to surface S5 is -2.2010 mm, indicating that the distance the light travels after being reflected by the second reflecting mirror 30 and then transmitted back to the first reflecting mirror 20 is 2.2010 mm.

[0075] Table 2 shows the higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface.

[0076] Table 2,

[0077] like Figure 2 The diagram illustrates the on-axis chromatic aberration curve of the camera module in Embodiment 1. The horizontal axis represents the defocus amount (in mm), and the vertical axis represents the on-axis chromatic aberration, which indicates the deviation of the focal point of light of different wavelengths after passing through the camera module. It can be seen that the chromatic aberration of red, green and blue light on the axis is controlled within a small range.

[0078] Figure 3The astigmatism curve of the camera module in Embodiment 1 is shown. The horizontal axis represents the defocus amount (in mm), and the vertical axis represents the half field of view, which indicates the meridional image plane curvature and the sagittal image plane curvature. Solid lines S1, S2, and S3 represent the meridional plane, and dashed lines T1, T2, and T3 represent the sagittal image plane. It can be seen that the astigmatism of red, green, and blue light along the axes is controlled within a small range.

[0079] Figure 4 The distortion curve of the camera module in Embodiment 1 is shown. The horizontal axis represents the distortion percentage and the vertical axis represents the half field of view. It represents the distortion value corresponding to different field of view angles. It can be seen that the distortion value of this camera module is relatively small.

[0080] Figure 5 The magnification chromatic aberration curve of the camera module in Embodiment 1 is shown. The horizontal axis represents lateral chromatic aberration, and the vertical axis represents the half field of view. This curve represents the deviation of different image heights on the imaging surface after light passes through the lens. It can be seen that the deviation of different image heights on the imaging surface after light passes through this camera module is within a small range. Solid lines represent long wavelengths, and dashed lines represent short wavelengths.

[0081] Combination Figures 2 to 5 Based on the analysis, the camera module given in Implementation 1 can achieve high-quality imaging with low chromatic dispersion.

[0082] like Figure 6 The diagram illustrates the structure of a camera module according to Embodiment 2. Along the optical axis, the camera module sequentially includes a first lens 11, a first reflector 20, a second reflector 30, and cemented third and fourth lenses 41 and 42. Table 3 illustrates the surface type, radius of curvature, thickness, material, and conic coefficient of each lens in the camera module of Embodiment 2. The units for radius of curvature and thickness are millimeters (mm).

[0083] Table 3,

[0084] As shown in Table 3, S1 to S13 are the surfaces through which light passes after passing sequentially through the first lens 11, the second reflecting mirror 30, the first reflecting mirror 20, the third lens 41, and the fourth lens 42. For example, S1 represents the object-side surface of the first lens 11, S2 represents the image-side surface of the first lens 11, S3 and S8 represent the object-side surface of the second reflecting mirror 30, and STO represents the aperture stop, which is also the object-side surface of the second reflecting mirror 30, S4 and S9 represent the image-side surface of the second reflecting mirror 30, S5 and S7 represent the image-side surface of the first reflecting mirror 20, S6 represents the object-side surface of the first reflecting mirror 20, S10 represents the object-side surface of the third lens 41, and since the third lens 41 and the fourth lens 42 are cemented together, S11 represents the image-side surface of the third lens 41 and the object-side surface of the fourth lens 42, and S12 represents the image-side surface of the fourth lens 42.

[0085] As shown in Table 3, the object-side surface of the first lens 11 is spherical with a radius of curvature of 64.0951; the thickness of the first lens 11 (distance from surface S1 to surface S2) is 1.9598 mm; the refractive index of the first lens 11 is 1.5176; and the Abbe number of the first lens 11 is 53.6. Similarly, the image-side surface of the fourth lens 42 is aspherical with a radius of curvature of 53.0862; the thickness of the fourth lens 42 (distance from surface S11 to surface S12) is 2.5322 mm; the distance from surface S12 to the imaging plane is 19.6854 mm; the refractive index of the fourth lens 42 is 1.74; and the Abbe number of the fourth lens 42 is 28.3.

[0086] Table 4 shows the higher-order coefficients A4, A6, A8, A10, A12, A14, and A16 for each aspherical surface in Implementation Method 2.

[0087] Table 4,

[0088] like Figure 7 The diagram illustrates the on-axis chromatic aberration curve of the camera module in Embodiment 2, which shows the deviation of the focal point of light of different wavelengths after passing through the lens. It can be seen that the chromatic aberration of red, green and blue light on the axis is controlled within a small range.

[0089] Figure 8 The astigmatism curves of the camera module in Embodiment 2 are shown, representing the meridional and sagittal image plane curvatures. Solid lines S1, S2, and S3 represent the meridional plane, while dashed lines T1, T2, and T3 represent the sagittal image plane. It can be seen that the astigmatism of red, green, and blue light along the axis is controlled within a relatively small range.

[0090] Figure 9 The distortion curve of the camera module in Embodiment 2 is shown, which represents the distortion value corresponding to different field of view angles. It can be seen that the distortion value of the light in this camera module is relatively small.

[0091] Figure 10 The magnification chromatic aberration curve of the camera module in Embodiment 2 is shown, which represents the deviation of different image heights on the imaging surface after light passes through the lens. It can be seen that the deviation of different image heights on the imaging surface after light passes through this camera module is within a small range.

[0092] Combination Figures 7 to 10 Based on the analysis, the camera module provided in Implementation Method 2 can achieve high-quality imaging with low chromatic dispersion.

[0093] Based on the experiments in Embodiments 1 and 2, the camera module in this application embodiment is a compact camera module capable of achieving a large aperture, sufficient aberration correction, and high performance. This camera module, combined with a Cassegrain-type reflective optical path, the optical power combination of the lens group 10, and the surface design of each lens element, can extend the focal length to over 200mm while ensuring image quality, thus achieving telephoto shooting. Taking a focal length of 242mm as an example, the overall size of the camera module can be comparable to that of a main camera with a focal length of 23mm~35mm, which is beneficial for laying the technological foundation for future diversified product categories.

[0094] The camera module described in this application embodiment has at least the following advantages: In the embodiments of this application, light passes through the lens group and is incident on the second reflecting mirror. The light is then reflected by the second reflecting mirror to the first reflecting mirror, and after further reflection by the first reflecting mirror, it travels from the light-transmitting area to the photosensitive element. The first and second reflecting mirrors can be used in conjunction to fold the light path, achieving an ultra-long focal length with a shorter optical path. Since the lens group includes a first lens with positive optical power, chromatic aberration can be corrected in advance using the first lens. Furthermore, the first lens can converge the light, allowing more light to reach the second reflecting mirror, thereby increasing the light transmission and achieving high-quality imaging. The camera module in the embodiments of this application achieves an ultra-long focal length with a shorter optical path while also providing high-quality imaging.

[0095] Secondly, embodiments of this application also disclose an electronic device, which may include the device body and the aforementioned camera module.

[0096] The device body described in the embodiments of this application may include, but is not limited to, mobile phones, computers, etc.

[0097] In some embodiments, the camera module can be integrated into the device body, and the camera module can be applied in the device body to realize the shooting function of the device body.

[0098] In other embodiments, the camera module is detachably connected to the device body, allowing the camera module to operate independently of the device body. In this case, the camera module can cooperate with the camera module in the device body to enhance the shooting function of the device body.

[0099] In some embodiments, the camera module can be detachably connected to the device body via an external structure, allowing the camera module to be externally mounted onto a traditional mobile phone. The external structure can be integrated with the camera module, or it can be a separate component. The external structure can attach the camera module to the device body via a clamping or snap-fit ​​method, or other methods may be used; this application does not specifically limit the specific methods employed.

[0100] The electronic device described in this application embodiment can achieve the same beneficial effects as the camera module described above, and will not be repeated here.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A camera module, characterized in that, include: A lens group (10), a first reflecting mirror (20), a second reflecting mirror (30), and a photosensitive element (50) are arranged sequentially along the optical axis. The reflective surfaces of the first reflector (20) and the second reflector (30) are positioned far apart from each other. The center of the second reflector (30) is provided with a light-transmitting area (31). After light passes through the lens group (10) and is incident on the second reflector (30), it is reflected by the second reflector (30) back to the first reflector (20), and after being reflected by the first reflector (20), it is incident on the photosensitive element (50) from the light-transmitting area (31). The lens group (10) includes a first lens (11) having positive optical power.

2. The camera module according to claim 1, characterized in that, The lens group (10) further includes a second lens (12) having negative optical power, and the second lens (12) is disposed between the first lens (11) and the first reflector (20).

3. The camera module according to claim 1, characterized in that, The photosensitive element (50) has an imaging surface that receives light, and the effective focal length of the camera module is f1; Along the optical axis, the axial distance from a point on the object side of the first lens (11) located on the optical axis to the imaging surface is L; When f1 ≥ 200 mm, the following condition is satisfied: 2.3 < f1 / L < 2.

8.

4. The camera module according to claim 1, characterized in that, The effective focal length of the camera module is f1, and the entrance pupil diameter of the camera module is D1. The relationship between D1 and f1 satisfies: 4.0 < f1 / D1 < 5.

0.

5. The camera module according to claim 1, characterized in that, The photosensitive element (50) has an imaging surface for receiving light, and the diagonal length of the imaging surface is H; Along the optical axis, the axial distance L from a point on the object side of the first lens (11) located on the optical axis to the imaging surface; The relationship between H and L satisfies: 0.4 < H / L < 0.

5.

6. The camera module according to claim 1, characterized in that, The outer diameter of the first lens (11) is D2; The photosensitive element (50) has an imaging surface that receives light, and the axial distance L from a point on the object side of the first lens (11) located on the optical axis to the imaging surface is as follows: The relationship between D2 and L satisfies: 0.5 < D2 / L < 1.

7. The camera module according to claim 2, characterized in that, The Abbe number of the first lens (11) is greater than the Abbe number of the second lens (12); and / or, The refractive index of the first lens (11) is less than the refractive index of the second lens (12); and / or, The surfaces of the first lens (11) and the second lens (12) are close to each other and are in contact.

8. The camera module according to claim 7, characterized in that, The Abbe number of the first lens (11) is vd1, and vd1 satisfies: 50 < vd1 < 70; The Abbe number of the second lens (12) is vd2, and vd2 satisfies: 20 < vd2 < 40; The refractive index of the first lens (11) is nd1, and nd1 satisfies: 1.4 < nd1 < 1.6; The refractive index of the second lens (12) is nd2, and nd2 satisfies: 1.65 < nd2 < 1.

85.

9. The camera module according to claim 2, characterized in that, The object side of the first lens (11) is convex, and the image side of the first lens (11) is concave. The object side of the second lens (12) is convex, and the image side of the second lens (12) is concave. The object side of the first reflector (20) is concave, and the image side of the first reflector (20) is convex. The object side of the second reflector (30) is concave, and the image side of the second reflector (30) is convex.

10. An electronic device, characterized in that, Includes the device body and the camera module as described in any one of claims 1-9; The camera module is integrated into the device body, or the camera module is detachably connected to the device body.

Images