Camera module and electronic equipment

Abstract

The invention discloses a camera module and electronic equipment. The camera module comprises a lens assembly and a prism from an object side to an image side; the lens assembly comprises a plurality of lenses which are arranged in sequence; the prism is located between the lens assembly and the imaging face and comprises a first working face, a second working face and a third working face, and light emitted by the lens assembly enters the prism from the first working face, is reflected to the first working face for the first time through the second working face and is reflected to the third working face for the second time through the first working face. The included angle between the first working face and the zero-view-field principal light is 90 degrees, and the included angle between the third working face and the zero-view-field principal light is 90 degrees. According to the camera module and the electronic equipment, the optical path of the rear focus of the lens is folded twice in the prism, and the working angle of the zero-view-field chief light is controlled, so that the height of the camera can be reduced, the imaging quality can be improved, and the use experience of a user is correspondingly improved.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to a camera module and electronic equipment. Background Art

[0002] With the development of multifunctionality of various electronic products, the camera function has become a necessary function of many electronic products, such as smart phones and tablet computers with camera functions. As a result, camera modules have also become a necessary component of various electronic devices.

[0003] However, conventional solutions for optical imaging of existing camera modules are as follows Figure 1 As shown, after the external light passes through the lens assembly 1 and the filter 2, it needs to go through a longer back focal length before reaching the imaging surface 3, which causes the camera module to be too high, the body to appear protruding, and affects the appearance of the entire device. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a camera module and an electronic device, which folds the lens back focus optical path twice inside the prism and controls the working angle of the zero field of view main light, thereby reducing the camera height and improving the imaging quality, thereby correspondingly improving the user experience. The present invention provides a camera module, which comprises a lens assembly and a prism from the object side to the image side; the lens assembly comprises a plurality of lenses arranged in sequence; the prism is located between the lens assembly and an imaging surface, and the prism comprises a first working surface, a second working surface and a third working surface; the light emitted from the lens assembly enters the prism from the first working surface, is reflected to the first working surface by the second working surface for the first time, is reflected to the third working surface by the first working surface for the second time, and is emitted to the imaging surface by the third working surface, wherein the angle between the first working surface and the zero-field-of-view main ray is 90°, and the angle between the third working surface and the zero-field-of-view main ray is 90°.

[0005] Optionally, the prism is a triangular prism structure.

[0006] Optionally, the first reflection and / or the second reflection is total reflection.

[0007] Optionally, the first working surface and / or the second working surface is provided with a reflective film.

[0008] Optionally, an included angle θ1 between the first working surface and the second working surface satisfies: 27°≤θ1≤33°.

[0009] Optionally, the distance L1 from the lens surface of the lens assembly to the first working surface, and the distance L2 from the first working surface to the lower end point of the imaging surface satisfy: 0.3 <L1 / L2<2.1。

[0010] Optionally, the focal length f' of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface, and the distance L2 from the first working surface to the lower end point of the imaging surface satisfy: 0.45 <f’ / (L1+L2)<1。

[0011] Optionally, the camera module further includes a filter, the filter is disposed between the lens assembly and the prism, the distance H10 between the lens assembly and the filter, the thickness H11 of the filter, and the distance H12 between the filter and the prism satisfy: 0.3 <H10+H11+H12。

[0012] Optionally, a first lens is disposed closest to the object side of the lens assembly, and the curvature radius P1R1 of the object side surface of the first lens, and the imaging circle diameter ImC of the camera module satisfies: 0.3 <P1R1 / ImC<0.9。

[0013] Optionally, a first lens is disposed closest to the object side in the lens assembly, and the curvature radius P1R1 of the object side surface of the first lens satisfies: <P1R1<10。

[0014] Optionally, a first lens is disposed closest to the object side of the lens assembly, the thickness of the first lens is H3, and the distance L1 from the lens surface of the lens assembly to the first working surface satisfies: 0.15 <H3 / L1<0.35。

[0015] Optionally, the lens assembly is provided with a first lens and a second lens in sequence on the object side, and the refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy: 0.6 <N1 / N2<1.5。

[0016] Optionally, the lens assembly is a telephoto lens assembly.

[0017] Optionally, the lens assembly includes a first lens, a second lens, a third lens and a fourth lens, and the first lens has positive optical power.

[0018] The present invention also provides an electronic device, comprising the above-mentioned camera module.

[0019] In the camera module and electronic device provided by the present invention, the light emitted from the lens assembly enters the prism from the first working surface, is reflected for the first time by the second working surface to the first working surface, is reflected for the second time by the first working surface to the third working surface, and is emitted to the imaging surface through the third working surface. The prism reflects the light twice inside and then emits it to the imaging surface, folds the lens back focus optical path twice inside the prism, and controls the working angle of the zero field of view main light, which can reduce the height of the camera and improve the imaging quality, thereby correspondingly improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of the optical structure of a camera module in the prior art is shown.

[0022] Figure 2 A schematic diagram of the optical structure of a camera module according to Example 1 of the present application is shown.

[0023] Figure 3 A distortion diagram of the camera module of Example 1 is shown.

[0024] Figure 4 A schematic diagram of the optical structure of a camera module according to Example 2 of the present application is shown.

[0025] Figure 5 The distortion diagram of the camera module of Example 2 is shown.

[0026] Figure 6 A schematic diagram of the optical structure of a camera module according to Example 3 of the present application is shown.

[0027] Figure 7 The distortion diagram of the camera module of Example 3 is shown.

[0028] Figure 8 A schematic diagram of the optical structure of a camera module according to Example 4 of the present application is shown.

[0029] Fig. 9 A distortion diagram of the camera module of Example 4 is shown. DETAILED DESCRIPTION

[0030] The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Through the description of the specific implementation methods, the technical means and effects adopted by the present invention to achieve the intended purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and illustration purposes, and are not used to limit the present invention. Some well-known parts may not be shown. In each of the drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not necessarily drawn strictly in accordance with the actual proportions.

[0031] It should be understood that the terms "first", "second", "third", "fourth", etc. are only used to distinguish components or circuits with similar properties, rather than indicating or implying relative importance or a specific order. The terms "include", "comprises", or any other variation thereof, are intended to cover non-exclusive inclusion, and may include other elements not explicitly listed in addition to those listed elements.

[0032] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0033] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] The features, principles and other aspects of the present application are described in detail below.

[0036] According to the camera module of the exemplary embodiment of the present application, from the object side to the image side, the lens assembly includes a plurality of lenses arranged in sequence; the prism is located between the lens assembly and the imaging surface, and the prism includes a first working surface, a second working surface, and a third working surface; the light emitted from the lens assembly enters the prism from the first working surface, is reflected to the first working surface by the second working surface for the first time, is reflected to the third working surface by the first working surface for the second time, and is emitted to the imaging surface through the third working surface, wherein the angle between the first working surface and the zero-field chief ray is 90°, and the angle between the third working surface and the zero-field chief ray is 90°. Thus, the original straight-line direction of the light can be changed by the prism, and the light is emitted to the imaging surface after being reflected twice inside the prism, and the back-focus optical path of the lens is folded inside the prism, so that the light emitted from the prism can reach the imaging surface after a shorter optical path, and the back-focus length of the lens is correspondingly shortened. Among them, the angle between the first working surface and the zero field of view chief ray is 90°, which can reduce astigmatism and other optical distortions caused by refraction, and can also reduce the generation of reflection, further reducing optical distortion, thereby helping to improve the imaging quality and accuracy of the optical system. In addition, no specific angle adjustment is required when installing between the lens assembly and the prism, which can facilitate the assembly of the prism. Among them, the angle between the third working surface and the zero field of view chief ray is 90°, and by controlling the angle between the third working surface and the zero field of view chief ray to be 90°, the zero field of view chief ray exit angle can be guaranteed to be 0°, which can reduce astigmatism and other optical distortions caused by refraction, and can also reduce the generation of reflection, further reducing optical distortion, thereby reducing the generation of chromatic aberration, avoiding dark corners or color cast in the picture, and helping to improve the imaging quality and accuracy of the optical system.

[0037] Among them, the prism of this embodiment is set to reflect the light only twice, because if only one reflection only changes the direction of the light, the optical path will not change much relative to the straight-line propagation path, and will occupy a longer space in the direction after the reflection, making the fuselage larger. If more than three reflections are performed, more than three reflection surfaces need to be set. In addition, considering the emission surface of the prism, the prism often needs to be set as a quadrilateral structure such as a trapezoid or a parallelogram, and each side of the quadrilateral structure will occupy a larger space, making the fuselage larger. Therefore, the prism of this embodiment only reflects the light twice, without occupying a larger space, and can change the original direction of the light and shorten the distance from the lens surface of the lens assembly to the lower end point of the imaging surface. The second working surface is the incident surface of the prism, and is also the reflection surface for the second reflection. The light undergoes a larger return in the prism and the optical path increases, so that the light is reflected from the second working surface to the third working surface, and only a smaller optical path is required to reach the imaging surface when it is emitted from the third working surface of the prism, which correspondingly shortens the back focal length of the lens. Thus, the camera module of this embodiment folds the lens back focus optical path twice inside the prism and controls the working angle of the zero field of view main light, so that the structure can be more compact, the camera height can be reduced, and the imaging quality can be improved. The appearance of the electronic device can be improved accordingly, and the user experience can be improved. At the same time, the prism structure used in this embodiment is no longer limited in the relative aperture of the lens compared to the existing periscope structure.

[0038] In an exemplary embodiment, according to the camera module of the present application, the prism is a triangular prism structure, that is, the three side surfaces of the triangular prism are respectively used as the first working surface, the second working surface and the third working surface. The prism structure is relatively simple and can meet the requirement that the prism reflects the light twice internally and then emits it to the imaging surface.

[0039] In an exemplary embodiment, according to the camera module of the present application, the first working surface and / or the second working surface is provided with a reflective film. Thus, when the light is reflected for the first time on the second working surface and / or when it is reflected for the second time on the second working surface, it can be ensured that the light can be completely reflected, reducing the risk of the light being refracted out of the prism when passing through the first working surface and / or the second working surface.

[0040] In an exemplary embodiment, according to the camera module of the present application, the first reflection and / or the second reflection is total reflection. Thus, by setting total reflection, there is no need to set an additional reflection layer such as a reflection film when the light is reflected, which can ensure that the light can be completely reflected, reducing the risk of the light being refracted out of the prism when passing through the first working surface and / or the second working surface.

[0041] In an exemplary embodiment, for the camera module according to the present application, the included angle θ1 between the first working surface and the second working surface satisfies: 27° ≤ θ1 ≤ 33°. By controlling the included angle θ1 between the first working surface and the second working surface, the second working surface and the first working surface can be used for internal double reflection of light, and the height of the camera can be significantly reduced.

[0042] In an exemplary embodiment, the camera module according to the present application may satisfy: 0.3 < L1 / L2 < 2.1; where L1 is the distance from the lens surface of the lens assembly to the first working surface, and L2 is the distance from the first working surface to the lower endpoint of the imaging surface. By satisfying 0.3 < L1 / L2 < 2.1 and controlling the distance from the lens surface of the lens assembly to the first working surface and the distance from the first working surface to the lower endpoint of the imaging surface, the thickness of the camera module can be controlled.

[0043] In an exemplary embodiment, the camera module according to the present application may satisfy: 0.45 < f’ / (L1 + L2) < 1; where the focal length of the camera module is f’, the distance from the lens surface of the lens assembly to the first working surface is L1, and the distance from the first working surface to the lower endpoint of the imaging surface is L2. By satisfying 0.45 < f’ / (L1 + L2) < 1 and controlling the focal length f’ of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface, and the distance L2 from the first working surface to the lower endpoint of the imaging surface, it is beneficial to reduce the height of the distance L1 from the lens surface of the lens assembly to the first working surface and the distance L2 from the first working surface to the lower endpoint of the imaging surface, which is conducive to miniaturization of the camera module.

[0044] In an exemplary embodiment, the camera module according to the present application further includes a diaphragm, and the diaphragm can be disposed, for example, on the object side surface of the first lens of the lens assembly, or between adjacent lenses, etc.

[0045] In an exemplary embodiment, the camera module according to the present application further includes an IR filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface. The IR filter can be disposed between the lens assembly and the prism, or at other positions, such as between the prism and the imaging surface, etc.

[0046] In an exemplary embodiment, the camera module according to the present application further includes a filter disposed between the lens assembly and the prism, and may satisfy: 0.3 < H10 + H11 + H12; where H10 is the distance between the lens assembly and the filter, H11 is the thickness of the filter, and H12 is the distance between the filter and the prism. By satisfying 0.3 < H10 + H11 + H12 and controlling the sum of the distance H10 between the lens assembly and the filter, the thickness H11 of the filter, and the distance H12 between the filter and the prism, it is beneficial to control the distance between the lens assembly and the prism and avoid collision between the lens assembly and the prism.

[0047] In an exemplary embodiment, for the camera module according to the present application, a first lens is disposed closest to the object side in the lens assembly, and it can satisfy: 0.3 < P1R1 / ImC < 0.9; where, the radius of curvature of the object side surface of the first lens is P1R1, and the imaging circle diameter of the camera module is ImC. Satisfying 0.3 < P1R1 / ImC < 0.9, by controlling the ratio of the radius of curvature P1R1 of the object side surface of the first lens and the imaging circle diameter ImC of the camera module, it is beneficial to control the curvature of each lens in the lens assembly under different target surfaces.

[0048] In an exemplary embodiment, for the camera module according to the present application, a first lens is disposed closest to the object side in the lens assembly, and it can satisfy: 2 < P1R1 < 10; where, the radius of curvature of the object side surface of the first lens is P1R1. Satisfying 2 < P1R1 < 10, by controlling the magnitude of the radius of curvature P1R1 of the object side surface of the first lens, it is beneficial to converge light through the first lens.

[0049] In an exemplary embodiment, for the camera module according to the present application, a first lens is disposed closest to the object side in the lens assembly, and it can satisfy: 0.15 < H3 / L1 < 0.35; where, the thickness of the object side surface of the first lens is H3, and the distance from the lens surface of the lens assembly to the first working surface is L1. Satisfying 0.15 < H3 / L1 < 0.35, by controlling the ratio of the thickness H3 of the object side surface of the first lens and the distance L1 from the lens surface of the lens assembly to the first working surface, it is beneficial to control the thickness of the first lens, and further reduce the lens height.

[0050] In an exemplary embodiment, for the camera module according to the present application, a first lens and a second lens are sequentially disposed closest to the object side in the lens assembly, and it can satisfy: 0.6 < N1 / N2 < 1.5; where, the refractive index of the first lens is N1, and the refractive index of the second lens is N2. Satisfying 0.6 < N1 / N2 < 1.5, by controlling the ratio of the refractive index N1 of the first lens and the refractive index N2 of the second lens, it is beneficial to reduce spherical aberration and obtain a better imaging effect.

[0051] In an exemplary embodiment, for the camera module according to the present application, a first lens and a second lens are sequentially disposed closest to the object side in the lens assembly, and it can satisfy: 30 < (Ab1 + Ab2) / 2 < 70; where, the Abbe number of the first lens is Ab1, and the Abbe number of the second lens is Ab2. Satisfying 30 < (Ab1 + Ab2) / 2 < 70, by controlling the Abbe number Ab1 of the first lens and the Abbe number Ab2 of the second lens, it is beneficial to correct chromatic aberration and obtain a better imaging effect.

[0052] In an exemplary embodiment, the camera module according to the present application can satisfy: 45 < Ab5; wherein, the Abbe number of the prism is Ab5. By satisfying 45 < Ab5 and controlling the magnitude of the Abbe number Ab5 of the prism, a large chromatic aberration introduced by the prism can be avoided, and a better imaging effect can be obtained.

[0053] In an exemplary embodiment, the lens assembly is preferably a telephoto lens assembly. The back focal length of the telephoto lens assembly is relatively longer than that of other lenses. By folding the back focal length of the lens inside the prism at least twice, the back focal length of the lens can be shortened. Combining the telephoto lens with the prism can significantly shorten the back focal length when using the telephoto lens.

[0054] In an exemplary embodiment, the lens assembly includes a first lens, a second lens, a third lens, and a fourth lens. The first lens has a positive optical power for converging light. When taking a picture, light passes through the first lens, the second lens, the third lens, and the fourth lens in sequence, and imaging can be performed on the imaging surface. By combining the positive and negative optical powers of multiple lenses, various aberrations can be balanced to obtain a clear image.

[0055] In one exemplary embodiment, the first lens has a positive optical power, the second lens has a negative optical power, the third lens has a positive optical power, and the fourth lens has a negative optical power. In another exemplary embodiment, the first lens has a positive optical power, the second lens has a negative optical power, the third lens has a negative optical power, and the fourth lens has a positive optical power. By combining the positive and negative optical powers of multiple lenses, various aberrations can be balanced to obtain a clear image.

[0056] Based on the same inventive concept, an electronic device according to an exemplary embodiment of the present application includes the above camera module. The electronic device includes but is not limited to smartphones, tablets, laptop computers, gimbal shooting devices, surveillance cameras, and other imaging devices. For the implementation of this electronic device, reference can be made to the embodiments of the camera module, and repeated parts will not be elaborated.

[0057] However, those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses constituting the optical imaging lens can be changed to obtain the various results and advantages described in this specification. For example, although four lenses are described as an example in the embodiment, the optical imaging lens is not limited to including four lenses. If necessary, the optical imaging lens may further include other numbers of lenses.

[0058] The following further describes specific embodiments of the camera module applicable to the above embodiments with reference to the accompanying drawings.

[0059] Example 1 The following reference Figure 2 and Figure 3 Describe the camera module according to Example 1 of the present application. Figure 2 A schematic diagram of the optical structure of a camera module according to Example 1 of the present application is shown.

[0060] like Figure 2 As shown, the camera module includes an object plane S1, an aperture S2, a lens assembly 10, a filter 20, a prism 30 and an imaging plane S16 in order from the object side to the image side, and the lens assembly 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14. The angle θ3 between the first working surface S13 and the zero field of view main ray is 90°, and the angle θ2 between the third working surface S15 and the zero field of view main ray is 90°. The filter 20 can be arranged between the lens assembly 10 and the prism 30. The first working surface S13 and / or the second working surface S14 can be provided with a reflective film.

[0061] The first lens 11 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The second lens 12 has negative optical power, and its object side surface S5 is convex, and its image side surface S6 is concave. The third lens 13 has positive optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fourth lens 14 has negative optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The filter 20 has an object side surface S11 and an image side surface S12. The prism 30 has a first working surface S13, a second working surface S14, and a third working surface S15. The light from the object passes through each surface S1 to S12 in sequence, and then is reflected for the first time on the second working surface S14, and is reflected for the second time on the first working surface S13, and then passes through the third working surface S15, and is finally imaged on the imaging surface S16.

[0062] Table 1 shows a basic parameter table of the camera module of Example 1, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0063] Table 1:

[0064] In Embodiment 1, the object side surface and the image side surface of any lens of the first lens 11 to the fourth lens 14 are both even-order aspheric surfaces, and the surface shape x of each aspheric lens can be defined by, but not limited to, the following aspheric surface formula: (1) Wherein, x is the sagitta, which is the distance from the vertex of the aspheric surface to the aspheric surface along the optical axis at a position with a height of h; c is the paraxial curvature of the aspheric 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 correction coefficient of the i-th order of the aspheric surface. Table 2 gives the higher-order term coefficients A2, A4, A6, A8, A10, A12, A14, and A16 for each aspheric mirror S3-10 in Example 1.

[0065] Table 2:

[0066] In this embodiment, the focal length of the camera module is 10.6 mm, the working wavelength band of the camera module is 410 - 650 nm, the aperture of the camera module is 2.4, the imaging circle of the camera module is 6.72 mm, the number of lens elements in the lens assembly is 4P, the distance L1 from the lens surface of the lens assembly to the first working surface S13 is 8.1 mm, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is 4 mm, satisfying: 0.3 < L1 / L2 < 2.1. The included angle θ1 between the first working surface S13 and the second working surface S14 is 30°. The relationship among the focal length f’ of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface S13, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is: f’ / (L1 + L2) = 0.88. The relationship among the distance H10 between the lens assembly 10 and the filter 20, the thickness H11 of the filter 20, and the distance H12 between the filter 20 and the prism 30 is: H10 + H11 + H12 = 1.05 mm. The relationship between the radius of curvature P1R1 of the object side surface of the first lens 11 and the imaging circle diameter ImC of the camera module is: P1R1 / ImC = 0.42. The radius of curvature P1R1 of the object side surface of the first lens 11 = 2.84. The relationship between the thickness H3 of the object side surface of the first lens 11 and the distance L1 from the lens surface of the lens assembly 10 to the first working surface S13 is: H3 / L1 = 0.25. The relationship between the refractive index N1 of the first lens 11 and the refractive index N2 of the second lens 12 is: N1 / N2 = 0.96. The relationship between the Abbe number Ab1 of the first lens 11 and the Abbe number Ab2 of the second lens 12 is: (Ab1 + Ab2) / 2 = 41.7. The Abbe number Ab5 of the prism = 63.9.

[0067] Figure 3 The distortion diagram of the camera module of Example 1 is shown, and the distortion is less than 2%, and the correction is very good. Therefore, in Example 1, not only the light is reflected at least twice inside the prism 30 and then emitted to the imaging surface S16, and the back focal optical path of the lens is folded inside the prism 30, which can shorten the back focal length of the lens and thus reduce the height of the camera, but also the presented camera module can achieve good imaging quality.

[0068] Example 2 The following reference Figure 4 and Figure 5 The camera module according to Embodiment 2 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted. Figure 4 A structural schematic diagram of a camera module according to Example 2 of the present application is shown.

[0069] like Figure 4 As shown, the camera module includes an object plane S1, an aperture S2, a lens assembly 10, a filter 20, a prism 30 and an imaging plane S16 in order from the object side to the image side, and the lens assembly 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14. The angle θ3 between the first working surface S13 and the zero field of view main ray is 90°, and the angle θ2 between the third working surface S15 and the zero field of view main ray is 90°. The filter 20 can be arranged between the lens assembly 10 and the prism 30. The first working surface S13 and / or the second working surface S14 can be provided with a reflective film.

[0070] The first lens 11 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The second lens 12 has negative optical power, and its object side surface S5 is convex, and its image side surface S6 is concave. The third lens 13 has negative optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fourth lens 14 has positive optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The filter 20 has an object side surface S11 and an image side surface S12. The prism 30 has a first working surface S13, a second working surface S14, and a third working surface S15. The light from the object passes through each surface S1 to S12 in sequence, and then is reflected for the first time on the second working surface S14, and is reflected for the second time on the first working surface S13, and then passes through the third working surface S15, and is finally imaged on the imaging surface S16.

[0071] Table 3 shows a basic parameter table of the camera module of Example 2, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0072] Table 3:

[0073] Table 4 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 2, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0074] Table 4:

[0075] In this embodiment, the focal length of the camera module is 10.45 mm, the working wavelength band of the camera module is 410 - 650 nm, the aperture of the camera module is 2.3, the imaging circle of the camera module is 6.84 mm, the number of lens elements in the lens assembly is 4P, the distance L1 from the lens surface of the lens assembly to the first working surface S13 is 6.9 mm, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is 3.8 mm, satisfying 0.3 < L1 / L2 < 2.1. The included angle θ1 between the first working surface S13 and the second working surface S14 is 27°. The relationship among the focal length f’ of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface S13, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is: f’ / (L1 + L2) = 0.98. The relationship among the distance H10 between the lens assembly 10 and the filter 20, the thickness H11 of the filter 20, and the distance H12 between the filter 20 and the prism 30 is: H10 + H11 + H12 = 1.05 mm. The relationship between the curvature radius P1R1 of the object side surface of the first lens 11 and the imaging circle diameter ImC of the camera module is: P1R1 / ImC = 0.37. The curvature radius P1R1 of the object side surface of the first lens 11 is 2.56. The relationship between the thickness H3 of the object side surface of the first lens 11 and the distance L1 from the lens surface of the lens assembly to the first working surface S13 is: H3 / L1 = 0.25. The relationship between the refractive index N1 of the first lens 11 and the refractive index N2 of the second lens 12 is: N1 / N2 = 1.01. The relationship between the Abbe number Ab1 of the first lens 11 and the Abbe number Ab2 of the second lens 12 is: (Ab1 + Ab2) / 2 = 60.35. The Abbe number Ab5 of the prism is 63.9.

[0076] Figure 5 The distortion diagram of the camera module of Embodiment 2 is shown. The distortion is less than 2% and the correction is very good. Thus, in Embodiment 2, not only the light is reflected at least twice inside by the prism 30 and then emitted to the imaging surface S16, folding the back focal optical path of the lens inside the prism 30, which can shorten the back focal length of the lens and thus reduce the height of the camera, but also the provided camera module can achieve good imaging quality.

[0077] Example 3 The following refers to Figure 6 and Figure 7 describe the camera module according to Embodiment 3 of the present application. In this embodiment, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 6 The structural schematic diagram of the camera module according to Embodiment 3 of the present application is shown.

[0078] As Figure 6As shown, the camera module includes an object plane S1, an aperture S2, a lens assembly 10, a filter 20, a prism 30 and an imaging plane S16 in order from the object side to the image side, and the lens assembly 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14. The angle θ3 between the first working surface S13 and the zero field of view main ray is 90°, and the angle θ2 between the third working surface S15 and the zero field of view main ray is 90°. The filter 20 can be arranged between the lens assembly 10 and the prism 30. The first working surface S13 and / or the second working surface S14 can be provided with a reflective film.

[0079] The first lens 11 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The second lens 12 has negative optical power, and its object side surface S5 is convex, and its image side surface S6 is concave. The third lens 13 has negative optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fourth lens 14 has positive optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The filter 20 has an object side surface S11 and an image side surface S12. The prism 30 has a first working surface S13, a second working surface S14, and a third working surface S15. The light from the object passes through each surface S1 to S12 in sequence, and then is reflected for the first time on the second working surface S14, and is reflected for the second time on the first working surface S13, and then passes through the third working surface S15, and is finally imaged on the imaging surface S16.

[0080] Table 5 shows a basic parameter table of the camera module of Example 3, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0081] Table 5:

[0082] Table 6 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0083] Table 6:

[0084] In this embodiment, the focal length of the camera module is 10.75 mm, the working wavelength band of the camera module is 410 - 650 nm, the aperture of the camera module is 2.45, the imaging circle of the camera module is 6.84 mm, the number of lenses in the lens assembly is 4P, the distance L1 from the lens surface of the lens assembly to the first working surface S13 is 7.4 mm, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is 4.4 mm, satisfying: 0.3 < L1 / L2 < 2.1. The included angle θ1 between the first working surface S13 and the second working surface S14 is 33°. The relationship among the focal length f’ of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface S13, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is: f’ / (L1 + L2) = 0.91. The relationship among the distance H10 between the lens assembly 10 and the filter 20, the thickness H11 of the filter 20, and the distance H12 between the filter 20 and the prism 30 is: H10 + H11 + H12 = 1.05 mm. The relationship between the curvature radius P1R1 of the object side surface of the first lens 11 and the imaging circle diameter ImC of the camera module is: P1R1 / ImC = 0.41. The curvature radius P1R1 of the object side surface of the first lens 11 is 2.81. The relationship between the thickness H3 of the object side surface of the first lens 11 and the distance L1 from the lens surface of the lens assembly to the first working surface S13 is: H3 / L1 = 0.25. The relationship between the refractive index N1 of the first lens 11 and the refractive index N2 of the second lens 12 is: N1 / N2 = 0.96. The relationship between the Abbe number Ab1 of the first lens 11 and the Abbe number Ab2 of the second lens 12 is: (Ab1 + Ab2) / 2 = 41.7. The Abbe number Ab5 of the prism is 63.9.

[0085] Figure 7 Fig. 4 shows the distortion diagram of the camera module of Embodiment 3. The distortion is less than 1% and the correction is very good. Therefore, in Embodiment 3, not only is the light reflected at least twice inside by the prism 30 and then emitted to the imaging surface S16, folding the back focal optical path of the lens inside the prism 30, which can shorten the back focal length of the lens and thus reduce the height of the camera, but also the provided camera module can achieve good imaging quality.

[0086] Example 4 The following refers to Figure 8 and Fig. 9 describe the camera module according to Embodiment 4 of the present application. In this embodiment, for the sake of simplicity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 8 Fig. 5 shows the structural schematic diagram of the camera module according to Embodiment 4 of the present application.

[0087] As Figure 8As shown, the camera module includes an object plane S1, an aperture S2, a lens assembly 10, a filter 20, a prism 30 and an imaging plane S16 in order from the object side to the image side, and the lens assembly 10 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14. The angle θ3 between the first working surface S13 and the zero field of view main ray is 90°, and the angle θ2 between the third working surface S15 and the zero field of view main ray is 90°. The filter 20 can be arranged between the lens assembly 10 and the prism 30. The first working surface S13 and / or the second working surface S14 can be provided with a reflective film.

[0088] The first lens 11 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The second lens 12 has negative optical power, and its object side surface S5 is convex, and its image side surface S6 is concave. The third lens 13 has negative optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fourth lens 14 has positive optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The filter 20 has an object side surface S11 and an image side surface S12. The prism 30 has a first working surface S13, a second working surface S14, and a third working surface S15. The light from the object passes through each surface S1 to S12 in sequence, and then is reflected for the first time on the second working surface S14, and is reflected for the second time on the first working surface S13, and then passes through the third working surface S15, and is finally imaged on the imaging surface S16.

[0089] Table 7 shows a basic parameter table of the camera module of Example 4, wherein the units of the curvature radius and thickness are both millimeters (mm).

[0090] Table 7:

[0091] Table 8 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 4, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0092] Table 8:

[0093] In this embodiment, the focal length of the camera module is 10.9 mm, the working wavelength band of the camera module is 410 - 650 nm, the aperture of the camera module is 2.4, the imaging circle of the camera module is 6.6 mm, the number of lens elements in the lens assembly is 4P, the distance L1 from the lens surface of the lens assembly to the first working surface S13 is 6 mm, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is 4 mm, satisfying 0.3 < L1 / L2 < 2.1. The included angle θ1 between the first working surface S13 and the second working surface S14 is 30°. The relationship among the focal length f’ of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface S13, and the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16 is: f’ / (L1 + L2) = 0.92. The relationship among the distance H10 between the lens assembly 10 and the filter 20, the thickness H11 of the filter 20, and the distance H12 between the filter 20 and the prism 30 is: H10 + H11 + H12 = 1.05 mm. The relationship between the curvature radius P1R1 of the object side surface of the first lens 11 and the imaging circle diameter ImC of the camera module is: P1R1 / ImC = 0.64. The curvature radius P1R1 of the object side surface of the first lens 11 = 4.22. The relationship between the thickness H3 of the object side surface of the first lens 11 and the distance L1 from the lens surface of the lens assembly to the first working surface S13 is: H3 / L1 = 0.24. The relationship between the refractive index N1 of the first lens 11 and the refractive index N2 of the second lens 12 is: N1 / N2 = 0.96. The relationship between the Abbe number Ab1 of the first lens 11 and the Abbe number Ab2 of the second lens 12 is: (Ab1 + Ab2) / 2 = 41.7. The Abbe number Ab5 of the prism = 63.9.

[0094] Fig. 9 Fig. 4 shows the distortion diagram of the camera module of Embodiment 4. The distortion is less than 1% and the correction is very good. Therefore, in Embodiment 4, the light is reflected at least twice inside the prism 30 and then emitted to the imaging surface S16, folding the back focal optical path of the lens inside the prism 30, which can shorten the back focal length of the lens, thereby reducing the height of the camera. Moreover, the provided camera module can achieve good imaging quality.

[0095] In summary, Table 9 shows the focal length, wavelength band, aperture, imaging circle, number of lens elements, the distance L1 from the lens surface of the lens assembly 10 to the first working surface S13, the distance L2 from the first working surface S13 to the lower endpoint of the imaging surface S16, the included angle θ1 between the first working surface S13 and the second working surface S14, the included angle θ2 between the third working surface S15 and the chief ray of the zero field of view, and the included angle θ3 between the first working surface S13 and the chief ray of the zero field of view for Embodiments 1 to 4.

[0096] Table 9:

[0097] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A camera module, characterized in that: From the object side to the image side includes: A lens assembly, the lens assembly comprising a plurality of lenses arranged in sequence; A prism, wherein the prism is located between the lens assembly and the imaging surface, and the prism comprises a first working surface, a second working surface and a third working surface; the light emitted from the lens assembly enters the prism from the first working surface, is reflected for the first time by the second working surface to the first working surface, is reflected for the second time by the first working surface to the third working surface, and is emitted to the imaging surface via the third working surface, wherein the angle between the first working surface and the zero field of view main ray is 90°, and the angle between the third working surface and the zero field of view main ray is 90°.

2. The camera module according to claim 1, characterized in that: The first working surface and / or the second working surface is provided with a reflective film.

3. The camera module according to claim 1, characterized in that: The distance L1 from the lens surface of the lens assembly to the first working surface, and the distance L2 from the first working surface to the lower end point of the imaging surface satisfy: 0.3 <L1 / L2<2.1。 4. The camera module according to claim 1, characterized in that: The focal length f' of the camera module, the distance L1 from the lens surface of the lens assembly to the first working surface, and the distance L2 from the first working surface to the lower end point of the imaging surface satisfy: 0.45 <f’ / (L1+L2)<1。 5. The camera module according to claim 1, characterized in that: It also includes a filter, which is arranged between the lens assembly and the prism, the distance H10 between the lens assembly and the filter, the thickness H11 of the filter, and the distance H12 between the filter and the prism satisfy: 0.3 <H10+H11+H12。 6. The camera module according to claim 1, characterized in that: The lens assembly is provided with a first lens closest to the object side, the curvature radius P1R1 of the object side surface of the first lens, and the imaging circle diameter ImC of the camera module satisfies: 0.3 <P1R1 / ImC<0.9。 7. The camera module according to claim 1, characterized in that: The lens assembly is provided with a first lens closest to the object side, and the curvature radius P1R1 of the object side surface of the first lens satisfies: <P1R1 <10。 8. The camera module according to claim 1, characterized in that: The lens assembly is provided with a first lens closest to the object side, the thickness of the first lens is H3, and the distance L1 from the lens surface of the lens assembly to the first working surface satisfies: 0.15 <H3 / L1 <0.35。 9. The camera module according to claim 1, characterized in that: The lens assembly is provided with a first lens and a second lens in sequence on the object side, and the refractive index N1 of the first lens and the refractive index N2 of the second lens satisfy: 0.6 <N1 / N2 <1.5。 10. An electronic device, characterized in that: Comprising a camera module as described in any one of claims 1 to 9.

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