Camera module and electronic device

Abstract

The present application relates to a camera module (20) and an electronic device (10). The camera module (20) comprises a first lens (L1) having positive optical power, a second lens (L2) having positive optical power, a third lens (L3) having negative optical power, and a fourth lens (L4) having negative optical power. The object side surface of the first lens (L1) near the optical axis is a convex surface. The object side surface of the second lens (L2) near the optical axis is a convex surface, and the image side surface of the second lens (L2) near the optical axis is a concave surface. Both the object side surface and the image side surface of the third lens (L3) near the optical axis are concave surfaces. The object side surface of the fourth lens (L4) near the optical axis is a convex surface, and the image side surface of the fourth lens (L4) near the optical axis is a concave surface. The fourth lens (L4) is fixed relative to an imaging surface (22). The first lens (L1), the second lens (L2), and the third lens (L3) constitute a focusing lens group (21). The focusing lens group (21) is movable along the optical axis relative to the fourth lens (L4).

Description

Camera module and electronic device

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 2024108661951, filed on June 28, 2024, and entitled "Camera module and electronic device", the contents of which are hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of camera devices, and in particular to a camera module and an electronic device. BACKGROUND

[0004] A camera module generally includes a lens group and an image sensor, and incident light is imaged on the image sensor after being adjusted by each lens in the lens group. In the camera module, a focusing driving element such as a voice coil motor is generally arranged to move the lens group or the image sensor to achieve the optical focusing function of the camera module. However, the arrangement of the focusing driving element in the camera module is prone to cause excessive increase in the occupied space of the camera module, which is not conducive to the miniaturization design of the camera module. SUMMARY

[0005] A camera module includes a focusing lens group and a fourth lens arranged on the image side of the focusing lens group, the position of the fourth lens is fixed relative to the imaging surface of the camera module, and the focusing lens group can move along the optical axis relative to the fourth lens.

[0006] The focusing lens group includes, in order from the object side to the image side along the optical axis, a first lens with positive refractive power, a second lens with positive refractive power, and a third lens with negative refractive power. The object side surface of the first lens is convex at the near optical axis, the object side surface of the second lens is convex at the near optical axis, and the image side surface of the second lens is concave at the near optical axis. The object side surface and the image side surface of the third lens are both concave at the near optical axis. The fourth lens has negative refractive power, the object side surface of the fourth lens is convex at the near optical axis, and the image side surface of the fourth lens is concave at the near optical axis.

[0007] An electronic device includes the camera module according to any one of the above embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the disclosed drawings.

[0009] FIG. 1 is a structural schematic diagram of an electronic device in some embodiments.

[0010] Fig. 2 is a schematic diagram of the structure of the camera module in the first embodiment.

[0011] Fig. 3 is a schematic diagram of the optical path of the optical conducting element in some embodiments.

[0012] Fig. 4 is a schematic diagram of the structure of the optical conducting element in some embodiments.

[0013] Fig. 5 is a schematic diagram of the structure of the camera module in the second embodiment.

[0014] Fig. 6 is a schematic diagram of the structure of the camera module in the third embodiment.

[0015] Fig. 7 is a graph of the astigmatism curve and the distortion curve of the camera module in the first embodiment.

[0016] Fig. 8 is a graph of the astigmatism curve and the distortion curve of the camera module in the second embodiment.

[0017] Fig. 9 is a graph of the astigmatism curve and the distortion curve of the camera module in the third embodiment.

[0018] Fig. 10 is a schematic diagram of the structure of the electronic device further comprising other components in some embodiments. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0020] As used herein, “electronic device” refers to a device capable of receiving and / or transmitting communication signals, including but not limited to any one or more of the following connection methods:

[0021] (1) via wired connection methods, such as via Public Switched Telephone Networks (PSTN), Digital Subscriber Line (DSL), digital cable, direct cable connection;

[0022] (2) via wireless interface methods, such as cellular networks, Wireless Local Area Network (WLAN), digital television networks such as DVB-H networks, satellite networks, AM-FM broadcast transmitters.

[0023] Electronic devices configured to communicate over wireless interfaces can be referred to as "mobile terminals." Examples of mobile terminals include, but are not limited to, the following electronic devices:

[0024] (1) a satellite phone or a cellular phone;

[0025] (2) a Personal Communications System (PCS) terminal that can combine a cellular radiotelephone with data processing, facsimile, and data communications capabilities;

[0026] (3) a radiotelephone, a pager, an Internet / Intranet access, a Web browser, a notepad, a calendar, a Personal Digital Assistant (PDA) equipped with a Global Positioning System (GPS) receiver;

[0027] (4) a conventional laptop and / or palmtop receiver;

[0028] (5) a conventional laptop and / or palmtop radiotelephone transceiver, and the like.

[0029] The application provides a camera module, comprising a focusing lens group and a fourth lens arranged on the image side of the focusing lens group, the position of the fourth lens is fixed relative to the imaging surface of the camera module, and the focusing lens group can move along the optical axis relative to the fourth lens.

[0030] The focusing lens group comprises, in order from the object side to the image side along the optical axis, a first lens with positive refractive power, a second lens with positive refractive power, and a third lens with negative refractive power, the object side surface of the first lens is convex at the near optical axis, the object side surface of the second lens is convex at the near optical axis, the image side surface of the second lens is concave at the near optical axis, and the object side surface and the image side surface of the third lens are both concave at the near optical axis; the fourth lens has negative refractive power, the object side surface of the fourth lens is convex at the near optical axis, and the image side surface of the fourth lens is concave at the near optical axis.

[0031] In one embodiment, the camera module satisfies the condition formula: 0.5≤|EFL1 / F4|≤0.8; wherein EFL1 is the effective focal length of the focusing lens group, and F4 is the effective focal length of the fourth lens.

[0032] In one embodiment, the camera module satisfies the condition formula: TTL / IMGH≤12; wherein TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis, and IMGH is the half image height of the camera module.

[0033] In one of the embodiments, the camera module satisfies a condition formula: 8°≤FOV≤20°; wherein, FOV is a maximum field of view angle of the camera module.

[0034] In one of the embodiments, the camera module satisfies a condition formula: 2.8≤EFL / EPD≤3.8; wherein, EFL is an effective focal length of the camera module, and EPD is an entrance pupil diameter of the camera module.

[0035] In one of the embodiments, the camera module satisfies a condition formula: 0.4≤F1 / EFL≤0.6; wherein, F1 is an effective focal length of the first lens, and EFL is an effective focal length of the camera module.

[0036] In one of the embodiments, the camera module satisfies a condition formula: 0.3≤R1 / F1≤0.7; wherein, R1 is a curvature radius of an object side surface of the first lens at an optical axis, and F1 is an effective focal length of the first lens.

[0037] In one of the embodiments, the object side surface and the image side surface of the first lens are both spherical surfaces, and the object side surface and the image side surface of at least one of the second lens, the third lens and the fourth lens are both aspherical surfaces.

[0038] In one of the embodiments, the maximum effective aperture of the first lens, the second lens, the third lens and the fourth lens decreases in turn.

[0039] In one of the embodiments, the camera module further comprises an image sensor arranged at the imaging surface and an optical transmission element arranged between the fourth lens and the image sensor along the optical axis, the optical transmission element being configured to transmit light to the image sensor after at least one reflection.

[0040] In one of the embodiments, the camera module satisfies a condition formula: 0.6≤L / TTL≤0.85; wherein, L is an optical path of light in the optical transmission element, and TTL is a distance from the object side surface of the first lens to the imaging surface along the optical axis.

[0041] In one of the embodiments, the optical transmission element is configured to transmit light to the image sensor after at least two reflections, so that the axis of the fourth lens is perpendicular to the imaging surface.

[0042] In one of the embodiments, the optical transmission element comprises a light-transmitting surface, a first reflecting surface and a second reflecting surface, the light-transmitting surface has a light-incoming region and a light-outgoing region, the light-incoming region is opposite to the fourth lens, the light-outgoing region is opposite to the image sensor, the first reflecting surface is obliquely opposite to the light-incoming region, and the second reflecting surface is obliquely opposite to the light-outgoing region.

[0043] In one of the embodiments, the optical conducting element comprises a light-transmitting surface, a first reflecting surface and a second reflecting surface, the light-transmitting surface has a light-incoming region and a light-outgoing region, the light-incoming region is opposite to the fourth lens, the light-outgoing region is opposite to the image sensor, a light ray incident on the optical conducting element from the light-incoming region can be reflected by the first reflecting surface, the light-transmitting surface and the second reflecting surface in sequence and then exit from the light-outgoing region.

[0044] In one of the embodiments, the optical conducting element comprises a light-transmitting surface, a first reflecting surface and a second reflecting surface, the light-transmitting surface has a light-incoming region and a light-outgoing region, the light-incoming region is opposite to the fourth lens, the light-outgoing region is opposite to the image sensor, a light ray incident on the optical conducting element from the light-incoming region can be reflected by the first reflecting surface and the second reflecting surface in sequence and then exit from the light-outgoing region.

[0045] In one of the embodiments, the image-side surface of the first lens is concave at the vicinity of the optical axis.

[0046] In one of the embodiments, the camera module comprises a diaphragm, the diaphragm is arranged on the object-side of the first lens.

[0047] In one of the embodiments, the camera module further comprises a focus driving element, the focus driving element is configured to drive the focus lens group to move along the optical axis relative to the imaging surface.

[0048] In one of the embodiments, the camera module further comprises an anti-shake driving element, the anti-shake driving element is configured to drive the focus lens group to move in a plane perpendicular to the optical axis.

[0049] The second aspect of the present application provides an electronic device comprising the camera module according to any one of the above embodiments.

[0050] Please refer to FIG. 1 and FIG. 2, FIG. 1 is a structural schematic diagram of an electronic device 10 in some embodiments, and FIG. 2 is a structural schematic diagram of a camera module 20 in some embodiments. The camera module 20 provided by the present application comprises but is not limited to any applicable electronic device 10 such as a smart phone, a tablet computer, an e-reader, a wearable device, etc., the camera module 20 can collect image information on the object side so that the electronic device 10 has the functions of image capturing and shooting, and the smart phone is taken as an example for illustration in each embodiment of the present application.

[0051] In some embodiments, the electronic device 10 further comprises a housing 11, and the camera module 20 is arranged in the housing 11. The housing 11 can comprise a middle frame and a back cover plate. The middle frame can be substantially in the shape of a rectangular frame. The back cover plate is arranged on one side of the middle frame. The camera module 20 is arranged in a receiving space formed by the back cover plate and the middle frame, and is exposed to the back cover plate to collect light on the side of the back cover plate of the electronic device 10. The electronic device 10 can further comprise a display screen, and the display screen is arranged on the side of the middle frame away from the back cover plate. When the camera module 20 is used to collect light on the side of the back cover plate of the electronic device 10, the camera module 20 can be a rear camera. In other embodiments, the camera module 20 can also be a front camera. In this case, the camera module 20 can be exposed to the side where the display screen is arranged, and is used to collect light on the side where the display screen is arranged. The electronic device 10 can further comprise other components to realize more functions, which will not be described herein.

[0052] Referring to FIGS. 2 and 3, in some embodiments, the camera module 20 comprises, along the optical axis from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4. Each lens comprises an object side surface facing the object side, and an image side surface facing the image side. The object side surface can be regarded as the light entrance surface of the lens, and the image side surface can be regarded as the light exit surface of the lens. The lenses in the camera module 20 can be coaxially arranged, and the optical axis of the camera module 20 passes through the common axis of the lenses. The camera module 20 further comprises an imaging surface 22 located on the image side of the fourth lens L4. The imaging surface 22 can be understood as the converging surface of the light from the object side after being adjusted by the lenses on the image side of the fourth lens L4. The imaging surface 22 can be a virtual plane. When the camera module 20 further comprises an image sensor 23 arranged on the image side of the fourth lens L4, the light sensitive surface of the image sensor 23 can coincide with the imaging surface 22. The light from the object side can be sequentially adjusted by the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, and then transmitted to the light sensitive surface of the image sensor 23 to form an image.

[0053] Further, in combination with FIG. 2 and FIG. 3, in some embodiments, the first lens L1 has positive refractive power, and the object side of the first lens L1 is convex at the near optical axis. The second lens L2 has positive refractive power, and the object side of the second lens L2 is convex at the near optical axis, and the image side is concave at the near optical axis. The third lens L3 has negative refractive power, and the object side and the image side of the third lens L3 are both concave at the near optical axis. The fourth lens L4 has negative refractive power, and the object side of the fourth lens L4 is convex at the near optical axis, and the image side is concave at the near optical axis. The fourth lens L4 is fixed relative to the imaging surface 22, and the first lens L1, the second lens L2 and the third lens L3 are fixed relative to each other to form the focusing lens group 21. The focusing lens group 21 can move relative to the fourth lens L4 and the imaging surface 22 along the optical axis on the object side of the fourth lens L4 to achieve the optical focusing function of the camera module 20. The camera module 20 can further include a focusing driving element 24, which can be but is not limited to a voice coil motor, and the focusing driving element 24 is used to drive the focusing lens group 21 to move along the optical axis relative to the fourth lens L4 and the imaging surface 22.

[0054] The camera module 20 described above, the positive refractive power of the first lens L1 and the convex design of the object side can effectively converge the incident light towards the image side, which is conducive to realizing the long focal design and avoiding excessive increase in the total optical length. The positive refractive power of the first lens L1 and the second lens L2 and the surface shape design complement each other, which can smoothly transition the light collected by the first lens L1 and suppress the generation of aberrations such as distortion, thereby being conducive to improving the imaging quality of the camera module 20 and reducing the burden of the third lens L3 and the fourth lens L4 to deflect light, reducing the surface shape design difficulty of the third lens L3 and the fourth lens L4, and reducing the tolerance sensitivity and aberration sensitivity of the camera module 20. The negative refractive power of the third lens L3 and the concave design of the object side and the image side can converge the light transmitted by the first lens L1 and the second lens L2 towards the image side, which is conducive to increasing the size of the imaging surface 22 and improving the imaging quality. The refractive power and surface shape design of the third lens L3, in combination with the negative refractive power and convex-concave surface shape design of the fourth lens L4, can reasonably transition the light to the imaging surface 22, improve the matching degree of the incident angle of the light on the imaging surface 22 and the image sensor 23, and be conducive to further improving the imaging quality of the camera module 20. Therefore, by designing the refractive power and surface shape of each lens, the lenses can jointly constrain the trend of the light path, suppress various aberrations such as distortion, improve the imaging quality of the camera module 20, and realize the long focal design.

[0055] And, the above-mentioned camera module 20 realizes the inner focusing function through the movement of the focusing lens group 21 composed of the first lens L1, the second lens L2 and the third lens L3 on the optical axis, and the focal length of the camera module 20 also changes during the focusing process, which can effectively shorten the focusing stroke of the focusing lens group 21 under the same range of object distance changes while realizing the long-focus design, reduce the stroke requirement of the camera module 20 to the focusing driving element 24, and the design of moving only three lenses is also conducive to reducing the load requirement of the camera module 20 to the focusing driving element 24, thereby being conducive to compressing the occupied space of the focusing driving element 24, and further conducive to compressing the volume of the camera module 20, conducive to realizing the miniaturization design, and facilitating the assembly of the camera module 20 in the electronic device 10. In addition, the design of moving the first lens L1, the second lens L2 and the third lens L3 as a whole relative to the fourth lens L4 to realize focusing, in cooperation with the optical power and surface type design of each lens, can effectively correct the aberration under different object distance states while reducing the focusing stroke, reasonably constrain the light path trend under different object distance states, so that the camera module 20 can have good imaging quality under different object distance states.

[0056] In some embodiments, the camera module 20 is provided with a diaphragm 25, which can be arranged on the object side of the first lens L1, and in other embodiments, the diaphragm 25 can also be arranged between any two lenses. In some embodiments, the camera module 20 further includes a filter 26 arranged between the fourth lens L4 and the imaging surface 22. The filter 26 includes but is not limited to an infrared cut-off filter 26, and the filter 26 is used to filter out interference light to prevent the interference light from reaching the imaging surface 22 and affecting normal imaging. Of course, the filter 26 can also be replaced by a protective glass or omitted, and when the filter 26 is omitted, the distance between the image side surface of the fourth lens L4 and the imaging surface 22 can remain unchanged.

[0057] In some embodiments, the object side and the image side of the first lens L1 are both spherical surfaces, and the object side and the image side of at least one of the second lens L2, the third lens L3 and the fourth lens L4 are both aspherical surfaces, and in this application, the object side and the image side of the second lens L2, the third lens L3 and the fourth lens L4 are taken as examples. In this way, the design difficulty, the preparation cost and the design flexibility can be considered, and the aspherical surface can effectively correct the spherical aberration and other aberrations, which is conducive to improving the imaging quality of the camera module 20. In some embodiments, the maximum effective aperture of the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 decreases in turn, which is conducive to the realization of long-focus design, increases the depth of field of the camera module 20, suppresses spherical aberration, chromatic aberration and other aberrations, reduces phenomena such as light halo and glare, and thus improves the imaging quality and long-focus shooting experience of the camera module 20. It can be understood that when a surface of a lens is a spherical surface, the surface types at the near optical axis and the circumference are the same, and when a surface of a lens is an aspherical surface, the surface types at the near optical axis and the circumference can be the same or different, and the surface type at the circumference can be designed according to the camera requirements, and in this application, the surface type at the circumference of each aspherical lens is not limited.

[0058] In some embodiments, the material of each lens in the camera module 20 can be glass or plastic. The lens made of plastic material can reduce the weight and production cost of the camera module 20, and cooperate with the small size of the camera module 20 to realize the lightweight design of the camera module 20. The lens made of glass material makes the camera module 20 have excellent optical performance and high temperature resistance. It should be noted that the material of each lens in the camera module 20 can also be any combination of glass and plastic, and it does not have to be all glass or all plastic.

[0059] In some embodiments, the camera module 20 satisfies the condition formula: 0.5≤|EFL1 / F4|≤0.8; wherein EFL1 is the effective focal length of the focusing lens group 21, and F4 is the effective focal length of the fourth lens L4. For example, |EFL1 / F4| can be 0.5, 0.6, 0.7 or 0.8. When the above condition formula is satisfied, the ratio of the effective focal lengths of the focusing lens group 21 and the fourth lens L4 can be reasonably configured, that is, the distribution relationship of the effective focal lengths of the focusing part and the fixed part of the camera module 20 is reasonably configured, which can effectively reduce the focusing stroke of the focusing lens group 21 while maintaining good imaging quality at different object distances.

[0060] In some embodiments, the camera module 20 satisfies a condition: TTL / IMGH≤12; where TTL is the distance from the object side surface of the first lens L1 to the imaging surface 22 on the optical axis, i.e., the total optical length of the camera module 20, and IMGH is the half image height of the camera module 20, which can be half of the diagonal length of the effective pixel area on the imaging surface 22 when the camera module 20 matches an image sensor 23 with a square photosurface. For example, TTL / IMGH can be 2, 5, 7, 8, 9, 11, or 12. Satisfying the above condition can reasonably configure the ratio of the total optical length and the half image height of the camera module 20, which is conducive to improving the matching degree of the camera module 20 structure and the image sensor 23, thereby improving the imaging quality of the camera module 20.

[0061] In some embodiments, the camera module 20 satisfies a condition: 8°≤FOV≤20°; where FOV is the maximum field of view angle of the camera module 20. For example, FOV can be 8, 10, 13, 15, 18, or 20, in units of °. By reasonably configuring the maximum field of view angle of the camera module 20, the long focal characteristic and the field of view angle can be balanced, so that the camera module 20 has a large enough field of view angle and good imaging quality while achieving long focal design.

[0062] In some embodiments, the camera module 20 satisfies a condition: 2.8≤EFL / EPD≤3.8; where EFL is the effective focal length of the camera module 20, and EPD is the entrance pupil diameter of the camera module 20. For example, EFL / EPD can be 2.8, 3, 3.2, 3.5, 3.6, or 3.8. When the above condition is satisfied, the relative aperture of the camera module 20 can be designed, which is conducive to increasing the aperture of the camera module 20 and improving the light throughput of the camera module 20, thereby improving the imaging quality of the camera module 20 in a weak light environment.

[0063] In some embodiments, the camera module 20 satisfies a condition: 0.4≤F1 / EFL≤0.6; where F1 is the effective focal length of the first lens L1, and EFL is the effective focal length of the camera module 20. For example, F1 / EFL can be 0.4, 0.5, or 0.6. When the above condition is satisfied, the ratio of the effective focal length of the first lens L1 and the effective focal length of the camera module 20 can be reasonably configured, so that the folding effect of the first lens L1 in the camera module 20 is reasonably distributed. The first lens L1 has sufficient folding power to fold large field of view light, effectively collects light, and improves the imaging quality of the camera module 20, while avoiding excessive folding power of the first lens L1 causing the surface to be too curved, which is conducive to reducing the tolerance sensitivity and aberration sensitivity of the first lens L1, and reducing the molding and assembly difficulty of the first lens L1.

[0064] In some embodiments, the camera module 20 satisfies a condition formula: 0.3≤R1 / F1≤0.7; where R1 is the radius of curvature of the object side surface of the first lens L1 at the optical axis, and F1 is the effective focal length of the first lens L1. For example, R1 / F1 can be 0.3, 0.4, 0.5, 0.6, or 0.7. When the above condition formula is satisfied, the ratio of the radius of curvature of the object side surface of the first lens L1 to the effective focal length of the first lens L1 can be reasonably configured, which is conducive to suppressing the spherical aberration and chromatic aberration generated by the first lens L1, and also conducive to avoiding strong total reflection ghosting of light in the first lens L1 due to excessive folding angle, thereby improving the imaging quality of the camera module 20.

[0065] In combination with FIGS. 2, 3, and 4, in some embodiments, the camera module 20 further includes an optical transmission element 27 disposed between the fourth lens L4 and the image sensor 23 along the optical axis, and the optical transmission element 27 is configured to transmit light to the image sensor 23 after at least one reflection. By reflecting light through the optical transmission element 27, the effect of folding the optical path can be achieved, for example, a periscopic design is achieved, which is conducive to reducing the size of the camera module 20 in the thickness direction of the electronic device 10 when the camera module 20 is used in the electronic device 10. It should be noted that, in order to facilitate the design of each lens, only a square glass is used to replace the optical transmission element 27 in FIGS. 2, 5, and 6, and the optical path in the square glass and the optical transmission element 27 is equal. In the embodiment shown in FIG. 3, four lenses are illustrated by four elliptical structures, and the shape and size of the lenses are not limited. The shape design of each lens in different embodiments is illustrated in FIGS. 2, 5, and 6, and the shape design of the optical transmission element 27 in one embodiment is illustrated in FIGS. 3 and 4.

[0066] In some embodiments, the optical transmission element 27 is configured to transmit light to the image sensor 23 after at least two reflections, so that the axis of the fourth lens L4 is perpendicular to the imaging surface 22, that is, the optical transmission element 27 can fold the optical path by 180°. For example, the optical transmission element 27 reflects the optical path three times in the embodiment shown in FIG. 3. In this way, the optical transmission element 27 can fold the optical path by multiple reflections, effectively compressing the volume of the optical transmission element 27. When the axes of the first lens L1 to the fourth lens L4 are parallel to the thickness direction of the electronic device 10, the height direction of the image sensor 23 and the optical filter 26 on the electronic device 10 coincides with the size of at least part of the lens, which can effectively compress the size of the camera module 20 in the thickness direction of the electronic device 10.

[0067] In combination with FIG. 1 and FIG. 3, in some embodiments, the shell 11 is provided with a light inlet hole 111 that penetrates the shell, and when the camera module 20 is accommodated in the shell 11, the light inlet side of the camera module 20 corresponds to the light inlet hole 111, so as to collect the light entering the light inlet hole 111, that is, the object side of the first lens L1 is opposite to the light inlet hole 111. In this way, the light inlet hole 111 can be circular in shape to adapt to the first lens L1 and be compatible with other hole structures of the electronic device 10, which is beneficial to improve the aesthetics of the electronic device 10, compared with the conventional light inlet hole 111 that is square in shape to adapt to the shape of the prism.

[0068] In some embodiments, the camera module 20 satisfies the condition: 0.6≤L / TTL≤0.85; where L is the optical path of the light in the optical transmission element 27, and TTL is the distance from the object side of the first lens L1 to the imaging surface 22 on the optical axis. For example, L / TTL can be 0.6, 0.71, 0.75, 0.79, 0.82 or 0.85. When the above condition is satisfied, the optical path occupied by the optical transmission element 27 in the camera module 20 can be reasonably configured to adapt to the telephoto design of the camera module 20, which is beneficial to the assembly of the camera module 20 while fully utilizing the optical transmission element 27 to fold the optical path.

[0069] In some embodiments, the optical transmission element 27 has a light-transmitting surface 271, a first reflecting surface 272 and a second reflecting surface 273, the light-transmitting surface 271 has a light inlet region 2711 and a light outlet region 2712, the light inlet region 2711 is opposite to the fourth lens L4, and the light outlet region 2712 is opposite to the image sensor 23, the first reflecting surface 272 is inclined to the light-transmitting surface 271 and is arranged corresponding to the light inlet region 2711, and the second reflecting surface 273 is inclined to the light-transmitting surface 271 and is arranged corresponding to the light outlet region 2712, that is, the projection of the first reflecting surface 272 on the light-transmitting surface 271 is at least partially within the range of the light inlet region 2711, and the projection of the second reflecting surface 273 on the light-transmitting surface 271 is at least partially within the range of the light outlet region 2712.

[0070] It can be understood that, after being adjusted by the first lens L1 to the fourth lens L4, at least part of the light rays emitted from the fourth lens L4 can enter the optical conduction element 27 from the light-in area 2711 and be incident on the first reflecting surface 272, the first reflecting surface 272 can reflect at least part of the light rays incident on the first reflecting surface 272 to the light-transmitting surface 271, the light-transmitting surface 271 can reflect at least part of the light rays reflected from the first reflecting surface 272 to the light-transmitting surface 271 to the second reflecting surface 273 in a total reflection manner, and the second reflecting surface 273 can reflect at least part of the light rays reflected from the light-transmitting surface 271 to the second reflecting surface 273 to the light-out area 2712, so that at least part of the light rays are emitted from the light-out area 2712 of the optical conduction element 27 and are incident on the image sensor 23. That is, the light rays incident on the optical conduction element 27 from the light-in area 2711 can be sequentially reflected by the first reflecting surface 272, the light-transmitting surface 271, and the second reflecting surface 273 and then emitted from the light-out area 2712. The total reflection on the light-transmitting surface 271 can be realized by designing the difference between the refractive index of the optical conduction element 27 and the refractive index of the air medium, and the reflecting film can be arranged on the first reflecting surface 272 and the second reflecting surface 273 to improve the light reflection rate.

[0071] In some embodiments, the included angles between the first reflecting surface 272 and the second reflecting surface 273 and the light-transmitting surface 271 are greater than or equal to 25° and less than or equal to 35°, for example, 32.5°. In this way, the efficiency and accuracy of the light reflection of the first reflecting surface 272, the second reflecting surface 273, and the light-transmitting surface 271 can be improved, so that the optical conduction element 27 can successfully fold the light path by 180°.

[0072] The optical conduction element 27 in the embodiment can reflect at least part of the light rays three times and then emit the light rays to the image sensor 23, so that the optical conduction element 27 is suitable for the long-focus design of the camera module 20, and through the periscopic design, the camera module 20 with the long-focus design can be arranged while the size of the camera module 20 in the thickness direction of the electronic device 10 is compressed, for example, the camera module 20 with a 2-4 times (equivalent focal length is about 40 mm-90 mm) magnification. When the camera module 20 has a higher magnification, the optical conduction element 27 can further fold the light rays more times to further lengthen the propagation path of the light rays in the optical conduction element 27, so as to adapt to the long-focus design of the camera module 20.

[0073] It should be noted that the first reflecting surface 272 and the second reflecting surface 273 can be connected to each other, that is, the optical transmission element 27 can be roughly in the shape of a triangular prism. Referring to FIG. 3, in some embodiments, the optical transmission element 27 can also have a bottom surface 274 connecting the first reflecting surface 272 and the second reflecting surface 273, the bottom surface 274 being opposite to the light transmission surface 271, for example, the bottom surface 274 is roughly parallel to the light transmission surface 271, so that the cross section of the optical transmission element 27 can be roughly in the shape of an isosceles trapezoid. Of course, the bottom surface 274 should be arranged to avoid the effective field of view range of the first reflecting surface 272 and the second reflecting surface 273, or partially correspond to the stray light part of the edge of the effective field of view, so as not to affect the normal imaging of the camera module 20. The bottom surface 274 of the optical transmission element 27 can be formed by cutting the triangular prism, or can be directly formed in the process of injection molding. On the basis of not affecting the imaging quality of the camera module 20, arranging the bottom surface 274 can reduce the size of the optical transmission element 27 in the thickness direction of the electronic device 10, which is conducive to the miniaturization design of the electronic device 10.

[0074] In some embodiments, the material of the optical transmission element 27 includes but is not limited to glass or plastic, and the refractive index of the optical transmission element 27 can be between 1.5 and 1.9, which can effectively deflect the light path and realize the periscopic design of the camera module 20, and can also reasonably plan the refractive index difference with the air medium, so that the light reflected from the first reflecting surface 272 can be totally reflected on the light transmission surface 271. For example, the material of the optical transmission element 27 can be glass, and the refractive index can be 1.61.

[0075] Of course, in another embodiment, by adjusting the angles between the first reflecting surface 272, the second reflecting surface 273 and the light transmission surface 271, the optical transmission element 27 can also reflect the light twice and then emit it, the first reflecting surface 272 can reflect the light towards the second reflecting surface 273, that is, the light incident on the optical transmission element 27 from the light incident area 2711 can be reflected by the first reflecting surface 272 and the second reflecting surface 273 in turn and then emitted from the light emission area 2712. In this embodiment, the angle between the first reflecting surface 272 and the light transmission surface 271, and the angle between the second reflecting surface 273 and the light transmission surface 271 can both be 45°, and the first reflecting surface 272 can be perpendicular to the second reflecting surface 273.

[0076] In some embodiments, the camera module 20 can further include an anti-shake driving element (not shown in the figure) for driving the focusing lens group 21 to move in a plane perpendicular to the optical axis. The anti-shake driving element can include a combination of any suitable elements such as a magnet, an electromagnet, etc., as long as it can drive the focusing lens group 21 to move in a plane perpendicular to the optical axis to achieve the optical anti-shake function of the camera module 20. In FIG. 3, the direction in which the focusing driving element 24 drives the focusing lens group 21 to move is shown by a solid double-headed arrow, and the direction in which the focusing driving element 24 drives the focusing lens group 21 to move is shown by a dashed double-headed arrow.

[0077] It can be understood that the camera module 20, the focusing driving element 24 and the anti-shake driving element only need to bear the weight of the first lens L1, the second lens L2 and the third lens L3, which is conducive to reducing the volume and cost of the focusing driving element 24 and the anti-shake driving element. The optical power and surface type of each lens are also conducive to reducing the focusing drive, further compressing the volume and cost of the focusing driving element 24. At the same time, the focusing lens group 21 is located on the side of the fourth lens L4 away from the optical transmission element 27, and the focusing driving element 24 and the anti-shake driving element are not easily interfered with the optical transmission element 27. The size of the focusing driving element 24 and the anti-shake driving element in the thickness direction of the electronic device 10 also overlaps with the size of the optical filter 26 and the image sensor 23, effectively compressing the volume of the camera module 20 and the size of the camera module 20 in the thickness direction of the electronic device 10, which is conducive to the miniaturization design of the camera module 20 and the electronic device 10.

[0078] According to the description of the above embodiments, the following more specific embodiments and drawings are proposed for detailed description.

[0079] Please refer to FIG. 2, which is a structural schematic diagram of the camera module 20 in the first embodiment. The parameters of the camera module 20 in the first embodiment are given in Table 1 below. In the embodiment shown in FIG. 2, a square glass is used as the optical transmission element 27. The optical path between the object side and the image side of the optical transmission element 27 is equal to the optical path between the light entrance area 2711 and the light exit area 2712 in the embodiment shown in FIG. 3, and the same applies to other embodiments. In the first embodiment and other embodiments below, the image side of the first lens L1 can be a concave surface.

[0080] Table 1

[0081] In the first embodiment, the aspheric coefficients of the object side and the image side of the second lens L2, the third lens L3 and the fourth lens L4 are given in Table 2 below, wherein A4-A20 represent the types of aspheric coefficients, A4 represents the fourth aspheric coefficient, A6 represents the sixth aspheric coefficient, A8 represents the eighth aspheric coefficient, and so on. The aspheric coefficient formula is as follows:

[0082] wherein Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the vertex of the surface, r is the distance from the corresponding point on the aspherical surface to the optical axis, c is the curvature of the vertex of the aspherical surface, K is the conic coefficient, and Ai is the coefficient corresponding to the i-th high-order term in the aspherical surface formula.

[0083] Table 2

[0084] In the first embodiment, the F-number of the camera module 20 is FNO = 3.28, and the maximum field of view is FOV = 12.4°. The close focus distance is 80 cm, and the focusing stroke of the focusing lens group 21 is 462 um. The anti-shake angle of the camera module 20 is 0.7°, and the anti-shake stroke of the focusing lens group 21 is ± 234 um.

[0085] Referring to FIG. 5, FIG. 5 is a structural schematic diagram of the camera module 20 in the second embodiment. The parameters of the camera module 20 in the second embodiment are given in Table 3 below.

[0086] Table 3

[0087] The aspherical coefficients of the object side and the image side of the second lens L2, the third lens L3 and the fourth lens L4 in the second embodiment are given in Table 4 below, wherein the meanings of the parameters can be obtained from the description of the first embodiment.

[0088] Table 4

[0089] In the second embodiment, the F-number of the camera module 20 is FNO = 3.5, and the maximum field of view is FOV = 12.6°. The close focus distance is 100 cm, and the focusing stroke of the focusing lens group 21 is 400 um. The anti-shake angle of the camera module 20 is 0.7°, and the anti-shake stroke of the focusing lens group 21 is ± 244 um.

[0090] Referring to FIG. 6, FIG. 6 is a structural schematic diagram of the camera module 20 in the third embodiment. The parameters of the camera module 20 in the third embodiment are given in Table 5 below.

[0091] Table 5

[0092] The aspherical coefficients of the object side and the image side of the second lens L2, the third lens L3 and the fourth lens L4 in the third embodiment are given in Table 6 below, wherein the meanings of the parameters can be obtained from the description of the first embodiment.

[0093] Table 6

[0094] In the third embodiment, the F-number FNO of the camera module 20 is 3.22, and the maximum field of view FOV is 12.6°. The close focus distance is 90 cm, and the focusing stroke of the focusing lens group 21 is 409 um. The anti-shake angle of the camera module 20 is 0.7°, and the anti-shake stroke of the focusing lens group 21 is ±233 um.

[0095] The above embodiments also satisfy the data in Table 7, the meanings of the parameters in Table 7, and the effects that can be obtained by satisfying the data in Table 7 can be obtained from the above description, and will not be described here.

[0096] Table 7

[0097] Please refer to FIGS. 7, 8 and 9, which are astigmatism and distortion curves of the camera module 20 in the first embodiment, the second embodiment and the third embodiment, respectively. As can be seen from FIGS. 7-9, the astigmatism and distortion of the camera module 20 in the embodiments of the present application are well controlled, and the camera module 20 has good imaging quality.

[0098] Referring to FIG. 10, which is a structural schematic diagram of an electronic device 10 provided in an embodiment of the present application. The electronic device 10 can include radio frequency (RF) circuit 501, memory 502 including one or more computer readable storage media, input unit 503, display unit 504, sensor 505, audio circuit 506, wireless fidelity (WiFi) module 507, processor 508 including one or more processing cores, and power supply 509, etc. Those skilled in the art can understand that the structure of the electronic device 10 shown in FIG. 10 does not constitute a limitation on the electronic device 10, and can include more or fewer components than shown, or combine certain components, or different component arrangements.

[0099] The radio frequency circuit 501 can be used for transmitting and receiving information, or receiving and sending signals in the process of communication. In particular, after receiving the downlink information from the base station, the radio frequency circuit 501 delivers the information to the one or more processors 508 for processing. In addition, the radio frequency circuit 501 sends the uplink data to the base station. Generally, the radio frequency circuit 501 includes, but is not limited to, an antenna, at least one amplifier, a tuner, one or more oscillators, a Subscriber Identity Module (SIM) card, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like. In addition, the radio frequency circuit 501 can communicate with a network and other devices through wireless communication. The wireless communication can use any communication standards or protocols, including but not limited to Global System for Mobile Communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Messaging Service (SMS), and the like.

[0100] The memory 502 can be used to store applications and data. The applications stored in the memory 502 include executable codes. The applications can constitute various functional modules. The processor 508 executes various functional applications and data processing by running the applications stored in the memory 502. The memory 502 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function (such as a sound playing function, an image playing function, and the like), and the like; the data storage area can store data created according to the use of the electronic device 10 (such as audio data, a phone book, and the like), and the like. In addition, the memory 502 can include a high-speed random access memory, and can further include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. Accordingly, the memory 502 can further include a memory controller to provide the processor 508 and the input unit 503 with access to the memory 502.

[0101] The input unit 503 can be configured to receive input of numbers, character information, or user-specific information (such as a fingerprint), and to generate a keyboard, mouse, joystick, optical, or trackball signal input related to user settings and function control. Specifically, in one embodiment, the input unit 503 can include a touch-sensitive surface and other input devices. The touch-sensitive surface, also known as a touch display or touchpad, can collect touch operations (such as a user's operation on or near the touch-sensitive surface using a finger, a stylus, or any suitable object or accessory) on or near the touch-sensitive surface and drive the corresponding connection device according to the pre-set program. Optionally, the touch-sensitive surface can include two parts, a touch detection device and a touch controller. The touch detection device detects the user's touch position and detects the signal generated by the touch operation and transmits it to the touch controller; the touch controller receives the touch information from the touch detection device and converts it into touch coordinates and sends it to the processor 508, and can also receive commands from the processor 508 and execute them.

[0102] The display unit 504 can be configured to display information input by a user or information provided to a user and various graphical user interfaces of the electronic device 10, which can be composed of graphics, text, icons, video, and any combination thereof. The display unit 504 can include a display panel. Optionally, the display panel can be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like. Further, the touch-sensitive surface can cover the display panel, and when the touch-sensitive surface detects a touch operation on or near it, it transmits to the processor 508 to determine the type of touch event, and then the processor 508 provides corresponding visual output on the display panel according to the type of touch event. Although in FIG. 10, the touch-sensitive surface and the display panel are implemented as two independent components to achieve input and output functions, in some embodiments, the touch-sensitive surface and the display panel can be integrated to achieve input and output functions. It can be understood that the display screen 110 can include the input unit 503 and the display unit 504.

[0103] The electronic device 10 can also include at least one sensor 505, such as a light sensor, a motion sensor, and other sensors. Specifically, the light sensor can include an ambient light sensor and a proximity sensor, where the ambient light sensor can adjust the brightness of the display panel according to the brightness of ambient light, and the proximity sensor can turn off the display panel and / or backlight when the electronic device 10 is moved to the ear. As one of the motion sensors, the gravity acceleration sensor can detect the magnitude of acceleration in each direction (generally three axes), and when at rest, can detect the magnitude and direction of gravity, and can be used for applications such as identifying the posture of the mobile phone (such as switching between horizontal and vertical screens, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometers, taps), and the like. As for other sensors that the electronic device 10 can also be configured, such as a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, and the like, they will not be described here.

[0104] The audio circuit 506 can provide an audio interface between the user and the electronic device 10 through the speaker and the microphone. The audio circuit 506 can convert received audio data into an electrical signal and transmit it to the speaker for conversion into a sound signal output by the speaker. On the other hand, the microphone collects a sound signal and converts it into an electrical signal, which is received by the audio circuit 506 and converted into audio data. The audio data is output to the processor 508 for processing, and then transmitted to another electronic device 10 via the radio frequency circuit 501, or output to the memory 502 for further processing. The audio circuit 506 can also include a headset jack to provide communication between an external device and the electronic device 10.

[0105] Wireless Fidelity (WiFi) is a short-range wireless transmission technology. The wireless Fidelity module 507 can help the user to send and receive emails, browse web pages, and access streaming media, etc. Although the wireless Fidelity module 507 is shown in FIG. 10, it is understood that it does not belong to the essential components of the electronic device 10, and can be omitted as needed without changing the essence of the application.

[0106] The processor 508 is the control center of the electronic device 10, which connects all parts of the electronic device 10 through various interfaces and lines, executes various functions of the electronic device 10 and processes data by running or executing application programs stored in the memory 502 and calling data stored in the memory 502, and thus monitors the entire electronic device 10. Optionally, the processor 508 can include one or more processing cores; optionally, the processor 508 can integrate an application processor and a modem processor, where the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communication. It is understood that the above-mentioned modem processor can also not be integrated into the processor 508.

[0107] The electronic device 10 also includes a power supply 509 for powering the various components. Optionally, the power supply 509 can be logically connected to the processor 508 through a power management system, such that the power management system enables functions such as managing charging, discharging, and power consumption management. The power supply 509 can also include one or more DC or AC power sources, recharging systems, power failure detection circuits, power converters or inverters, power status indicators, and the like.

[0108] Although not shown in FIG. 10, the electronic device 10 can also include a Bluetooth module or the like, which will not be described herein. In a specific implementation, the above modules can be implemented as independent entities, or can be combined as one or more entities, and the specific implementation of the above modules can be referred to the method embodiments described above, which will not be described herein.

[0109] The technical features of the above embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as falling within the scope of the present disclosure.

[0110] The above embodiments only express several implementation manners of the present application, and the description is specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A camera module, comprising a focusing lens group and a fourth lens disposed on the image side of the focusing lens group, wherein the position of the fourth lens is fixed relative to the imaging surface of the camera module, and the focusing lens group is movable relative to the fourth lens along the optical axis; The focusing lens assembly includes, along the optical axis from the object side to the image side, a first lens with positive optical power, a second lens with positive optical power, and a third lens with negative optical power. The object side of the first lens is convex near the optical axis, the object side of the second lens is convex near the optical axis, and the image side is concave near the optical axis. Both the object side and the image side of the third lens are concave near the optical axis. The fourth lens has negative optical power, and its object side is convex near the optical axis, while its image side is concave near the optical axis.

2. The camera module according to claim 1, wherein, The camera module satisfies the condition: 0.5≤|EFL1 / F4|≤0.8; Wherein, EFL1 is the effective focal length of the focusing lens group, and F4 is the effective focal length of the fourth lens.

3. The camera module according to claim 1, wherein, The camera module satisfies the condition: TTL / IMGH≤12; Wherein, TTL is the distance on the optical axis from the object side of the first lens to the imaging surface, and IMGH is the half-image height of the camera module.

4. The camera module according to claim 1, wherein, The camera module satisfies the condition: 8°≤FOV≤20°; Wherein, FOV is the maximum field of view of the camera module.

5. The camera module according to claim 1, wherein, The camera module satisfies the condition: 2.8 ≤ EFL / EPD ≤ 3.8; Wherein, EFL is the effective focal length of the camera module, and EPD is the entrance pupil diameter of the camera module.

6. The camera module according to claim 1, wherein, The camera module satisfies the condition: 0.4≤F1 / EFL≤0.6; Wherein, F1 is the effective focal length of the first lens, and EFL is the effective focal length of the camera module.

7. The camera module according to claim 1, wherein, The camera module satisfies the condition: 0.3≤R1 / F1≤0.7; Wherein, R1 is the radius of curvature of the object side of the first lens at the optical axis, and F1 is the effective focal length of the first lens.

8. The camera module according to any one of claims 1-7, wherein, The object-side surface and image-side surface of the first lens are both spherical, while the object-side surface and image-side surface of at least one of the second lens, the third lens, and the fourth lens are both aspherical.

9. The camera module according to any one of claims 1-7, wherein, The maximum effective aperture of the first lens, the second lens, the third lens, and the fourth lens decreases sequentially.

10. The camera module according to any one of claims 1-7, wherein, The camera module also includes an image sensor disposed at the imaging surface and an optical transmission element disposed along the optical axis between the fourth lens and the image sensor. The optical transmission element is used to transmit light to the image sensor after at least one reflection.

11. The camera module according to claim 10, wherein, The camera module satisfies the condition: 0.6≤L / TTL≤0.85; Where L is the optical path length of the light within the optical transmission element, and TTL is the distance on the optical axis from the object side of the first lens to the imaging surface.

12. The camera module according to claim 10, wherein, The optical transmission element is used to transmit light to the image sensor after at least two reflections, so that the axis of the fourth lens is perpendicular to the imaging surface.

13. The camera module according to claim 12, wherein, The optical transmission element includes a light-transmitting surface, a first reflective surface, and a second reflective surface. The light-transmitting surface has an incident light area and an exit light area. The incident light area is opposite to the fourth lens, and the exit light area is opposite to the image sensor. The first reflective surface is obliquely opposite to the incident light area, and the second reflective surface is obliquely opposite to the exit light area.

14. The camera module according to claim 12, wherein, The optical transmission element includes a light-transmitting surface, a first reflective surface, and a second reflective surface. The light-transmitting surface has an incident light area and an exit light area. The incident light area is opposite to the fourth lens, and the exit light area is opposite to the image sensor. Light rays incident on the optical transmission element from the incident light area can be reflected sequentially by the first reflective surface, the light-transmitting surface, and the second reflective surface before exiting from the exit light area.

15. The camera module according to claim 12, wherein, The optical transmission element includes a light-transmitting surface, a first reflective surface, and a second reflective surface. The light-transmitting surface has an incident light area and an exit light area. The incident light area is opposite to the fourth lens, and the exit light area is opposite to the image sensor. Light rays incident on the optical transmission element from the incident light area can be reflected sequentially by the first reflective surface and the second reflective surface and then exit from the exit light area.

16. The camera module according to any one of claims 1-7, wherein, The image-side surface of the first lens is concave near the optical axis.

17. The camera module according to any one of claims 1-7, wherein, The camera module includes an aperture stop, which is located on the object side of the first lens.

18. The camera module according to any one of claims 1-7, wherein, The camera module also includes a focus driving element, which is used to drive the focusing lens group to move relative to the imaging surface along the optical axis.

19. The camera module according to any one of claims 1-7, wherein, The camera module also includes an image stabilization drive element, which is used to drive the focusing lens group to move in a plane perpendicular to the optical axis.

20. An electronic device comprising a camera module as described in any one of claims 1-19.

Images