Electronic device

Abstract

The utility model provides electronic equipment, and relates to the technical field of terminal equipment, and the electronic equipment comprises a housing, a sound production device, and a sound insulation plate. A first cavity is formed in the shell. The sound production device is installed in the shell, and the first cavity forms at least part of a rear cavity of the sound production device. The sound insulation plate is located in the first cavity. The sound insulation board comprises at least one sound insulation unit, each sound insulation unit comprises a flexible film, a mass block and an annular frame, the surface of one side of the flexible film in the thickness direction is a first surface, the mass block and the annular frame are both fixed to the flexible film, and the mass block is located in the annular frame and located in the center of the first surface. The electronic equipment is used for solving the problem that a sound production device drives a shell of the electronic equipment to generate vibration, and the experience feeling of a user is greatly influenced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of terminal equipment, in particular to an electronic device. BACKGROUND

[0002] The sound production device is used for restoring audio electrical signals such as music and voice into sound, and has the function of supporting audio external playing, so it has been more and more widely applied in electronic devices such as mobile phones, tablet computers and notebook computers.

[0003] With the vibration sound production of the sound production device, the sound production device drives the shell of the electronic device to vibrate, which greatly affects the user experience. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the present application provides an electronic device to solve the problem that the sound production device drives the shell of the electronic device to vibrate, which greatly affects the user experience.

[0005] To achieve the above purpose, the present application adopts the following technical scheme:

[0006] The present application provides an electronic device, which comprises a shell, a sound production device and a sound insulation board. The shell has a first cavity. The sound production device is installed in the shell, and the first cavity constitutes at least part of the back cavity of the sound production device. The sound insulation board is located in the first cavity. The sound insulation board comprises at least one sound insulation unit, the sound insulation unit comprises a flexible film, a mass block and a ring-shaped frame, one side surface of the flexible film in the thickness direction is a first surface, the mass block and the ring-shaped frame are both fixed to the flexible film, the mass block is located in the ring-shaped frame and at the center of the first surface.

[0007] In this way, when the sound wave is incident on the sound insulation board, the mass block will be excited to drive the flexible film to vibrate. The flexible film utilizes its own structural characteristics, and the flexible film will vibrate with the mass block to control the vibration of the mass block in the vibration state. As long as the incident frequency of the sound wave and the resonance frequency of the mass block on the flexible film are matched, the central region of the sound insulation board (i.e. the mass block) and the edge region of the sound insulation board (i.e. the flexible film) are in anti-phase resonance to inhibit sound propagation. Therefore, the responses of the mass block and the flexible film to the sound wave in the transmission direction of the sound wave are different, so that the displacement of the flexible film vibration (and the displacement direction of the mass block vibration) can produce a certain degree of cancellation or complete cancellation through the displacement of the flexible film and the mass block vibration, so that the displacement of the entire sound insulation board tends to 0mm or equals to 0mm. Thus, the sound insulation board can intercept and block the vibration sound wave generated by the vibration of the diaphragm group to a certain extent, which is conducive to reducing the vibration sound wave transmitted to the shell to a certain extent, thereby weakening the vibration of the shell, realizing the vibration reduction function of the sound insulation board to the shell and improving the user experience.

[0008] In some embodiments of the present application, the sound insulation unit has a sound insulation amount greater than or equal to 40 dB. In this way, the sound insulation board can achieve better sound insulation and vibration reduction effects in the electronic device.

[0009] In some embodiments of the present application, the sound insulation board includes a plurality of sound insulation units,

[0010] The plurality of sound insulation units are arranged in the direction of the first surface, and the flexible membranes of any two adjacent sound insulation units are connected together.

[0011] In this way, on the one hand, based on the fact that the sound insulation amount of the sound insulation board is the sum of the sound insulation amounts of the sound insulation units, by providing a plurality of sound insulation units on the sound insulation board, the number of sound insulation units is increased, thereby improving the sound insulation and vibration reduction effects of the sound insulation board; on the other hand, by connecting the flexible membranes of the two adjacent sound insulation units on the sound insulation board together, the area of the flexible membrane is increased, thereby improving the structural strength of the sound insulation board.

[0012] In some embodiments of the present application, the plurality of sound insulation units are arranged in a rectangular array. In this way, the sound insulation units are uniformly distributed on the sound insulation board, facilitating the processing and manufacturing of the sound insulation board, and the sound insulation consistency of each sound insulation unit on the sound insulation board is better.

[0013] In some embodiments of the present application, the plurality of sound insulation units are arranged in the plane of the first surface, and the flexible membranes of the plurality of sound insulation units are connected together.

[0014] In this way, on the one hand, by providing a plurality of sound insulation units on the sound insulation board, the number of flexible membranes and mass blocks is increased, thereby improving the sound insulation and vibration reduction effects of the sound insulation board; on the other hand, by connecting the annular frames of the two adjacent sound insulation units on the sound insulation board together, the structural strength of the sound insulation board is improved.

[0015] In some embodiments of the present application, the plurality of annular frames are connected together. In this way, the structural strength of the sound insulation board is improved, the processing technology of the sound insulation board is simplified, and the manufacturing cost is reduced.

[0016] In some embodiments of the present application, an elastic material layer is arranged between the annular frame and the inner surface of the shell.

[0017] In this way, since the elastic material layer has damping properties, arranging the elastic material layer between the sound insulation board and the back cover is beneficial to further absorbing part of the energy of the sound waves by utilizing the damping properties of the elastic material layer, thereby preventing the vibration of the sound insulation board from being transmitted to the back cover, increasing a layer of vibration reduction barrier between the sound insulation board and the back cover, and improving the vibration reduction effect.

[0018] In some embodiments of the present application, the flexible film, the annular frame and the inner surface of the shell form a sealed cavity, and the sealed cavity is filled with a first gas; the density of the first gas is different from that of air. In this way, by filling the sealed cavity with a first gas having a density different from that of air outside the sealed cavity, a pressure difference is formed between the sealed cavity and the air, and the sound insulation and vibration reduction performance of the sound insulation plate on the back cover is realized.

[0019] In some embodiments of the present application, the Young's modulus of the flexible film is E, E is greater than or equal to e 9 Pa, and less than or equal to 9e 9 Pa.

[0020] In this way, by increasing the Young's modulus of the flexible film within a certain range, the bending stiffness can be equivalent to be improved, the peak and bandwidth can be improved, the sound insulation amount can be increased, and the low-frequency sound insulation and vibration reduction function of the sound insulation unit can be further improved.

[0021] In some embodiments of the present application, the radius Rm of the mass block is greater than or equal to 0.8e -3 m, and less than or equal to 1.2e -3 m.

[0022] In this way, by increasing the radius of the mass block within a certain range, the overall frequency can be shifted upwards, and the sound insulation amount can be increased, which is beneficial to the low-frequency sound insulation and vibration reduction performance of the sound insulation unit.

[0023] In some embodiments of the present application, the resonance frequency of the sound insulation unit is f, and f is less than or equal to 500 Hz.

[0024] In this way, the sound insulation plate can intercept or block the vibration sound waves below 500 Hz generated when the diaphragm group vibrates to a certain extent, which is beneficial to at least reducing the vibration sound waves transmitted to the shell to a certain extent, thereby weakening the vibration of the shell, realizing the vibration reduction function of the sound insulation plate on the shell, and improving the user experience.

[0025] In some embodiments of the present application, the mass block is made of metal. In this way, based on the fact that the stiffness of metal is greater than that of the flexible film, the mass block can be used to counterbalance the flexible film during vibration reduction to control the surface tension of the flexible film.

[0026] In some embodiments of the present application, the shell includes a back cover, a frame and a middle plate, the middle plate is arranged in layers with the back cover, the middle plate is fixed in the frame, the back cover is arranged on one side of the frame and fixedly connected with the frame, the sound generating device is fixed to the middle plate, the middle plate, the frame and the back cover form a first cavity, and the sound insulation plate is fixed to the surface of the back cover facing the middle plate.

[0027] In this way, the sound generating device occupies a relatively large area in the electronic device, and the vibration intensity of the back cover is high when the sound generating device vibrates. Therefore, the sound insulation plate is fixed to the surface of the back cover facing the middle plate, which is beneficial to the sound insulation and vibration reduction performance of the sound insulation plate.

[0028] In some embodiments of the present application, the vertical projection of the sound generating device on the back cover overlaps the vertical projection of the sound insulation plate on the back cover.

[0029] In this way, by overlapping the vertical projection of the sound generating device on the back cover with the vertical projection of the sound insulation plate on the back cover, the sound insulation plate can intercept and block the vibration sound waves at this position, reduce the vibration amplitude of the back cover at this position, and improve the vibration reduction effect of the back cover. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A perspective view of an electronic device according to some embodiments of the present application;

[0031] Figure 2 An exploded view of an electronic device according to Figure 1 ;

[0032] Figure 3 A partial cross-sectional view of an electronic device according to Figure 1 ;

[0033] Figure 4 An enlarged view of a core in an electronic device according to Figure 3 ;

[0034] Figure 5 An exploded view of another electronic device according to the present application;

[0035] Figure 6 A partial cross-sectional view of an electronic device according to Figure 5 ;

[0036] Figure 7 A schematic view of a sound insulation plate in an electronic device according to Figure 5 ;

[0037] Figure 8 A structural schematic view of a sound insulation unit in a sound insulation plate according to Figure 7 ;

[0038] Figure 9 A cross-sectional schematic view of an electronic device 100 according to Figure 5 ;

[0039] Figure 10 A vibration displacement cloud map of a sound insulation unit;

[0040] Figure 11A test schematic diagram of the sound insulation board on the back cover vibration position is shown.

[0041] Figure 12 A schematic diagram of the vibration acceleration level of the back cover of the simulation experimental group and the control group according to the position X is shown. Figure 11

[0042] Figure 13 A schematic diagram of the vibration acceleration level of the back cover of the simulation experimental group and the control group according to the position a is shown. Figure 11

[0043] Figure 14 A schematic diagram of the vibration mode of the sound insulation board in the full frequency band is shown.

[0044] Figure 15 A vibration displacement nephogram of the sound insulation board at the sound insulation valley fd1 is shown.

[0045] Figure 16 A vibration displacement nephogram of the sound insulation board at the sound insulation valley fd2 is shown.

[0046] Figure 17 A vibration displacement nephogram of the sound insulation board at the sound insulation peak fp is shown.

[0047] Figure 18 A sound insulation curve diagram of the sound insulation board with different equivalent radii Rm values of the mass block and the frequency relationship of the sound insulation amount is shown.

[0048] Figure 19 A sound insulation curve diagram of the sound insulation board with different Young's modulus E values of the flexible film 811 and the frequency relationship of the sound insulation amount is shown.

[0049] Figure 20 A curve diagram obtained by simulating the tension of the flexible film on the vibration displacement of the back cover is shown.

[0050] Figure 21 A curve diagram of the vibration displacement of the back cover when different gases are filled in the sound insulation unit.

[0051] Reference signs:

[0052] 100-electronic device;

[0053] 1-screen; 11-light-transmitting cover plate; 12-display screen;

[0054] 2-bezel; 21-middle plate;

[0055] 3-back cover;

[0056] 4-main circuit board;

[0057] 5-secondary circuit board;

[0058] 6-battery; ​​

[0059] 7- sound production device; 71- shell; 72- inner core; 721- pot frame; 722- diaphragm group; 7221- fixed part; 7222- folded ring; 7223- ball top; 723- voice coil; 724- magnetic circuit system; 7241- magnetic gap;

[0060] 8- sound insulation board; 81- sound insulation unit; 811- flexible film; 8111- first surface; 812- mass block; 813- annular frame;

[0061] 10- sound hole; K1- front cavity; K2- rear cavity; Q- first cavity; T- elastic material layer; E- sealed cavity. DETAILED DESCRIPTION

[0062] In the embodiments of the present application, the terms "first", "second" are only used for descriptive purpose, and can not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0063] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, "connection" can be detachable connection, or can be non-detachable connection; can be direct connection, or can be indirect connection through intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection is unchanged.

[0064] In the embodiments of the present application, "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0065] In the description of the embodiments of the present application, the terms "including", "containing" or any other variants thereof are intended to cover non-exclusive containing, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the existence of other same elements in the process, method, article or device including the element.

[0066] The present application provides an electronic device, which is a kind of electronic device with support for audio playback function. Specifically, the electronic device can be a portable electronic device or other suitable electronic device. For example, the electronic device can be a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a notebook computer, a vehicle-mounted device, a wearable device (such as a watch or a bracelet), augmented reality (AR) glasses, an AR helmet, virtual reality (VR) glasses, or a VR helmet, etc.

[0067] Please refer to Figure 1 and Figure 2 , wherein, Figure 1 is a perspective view of an electronic device 100 of some embodiments of the present application; Figure 2 is an exploded view of the electronic device 100 shown in Figure 1 . In this embodiment, the electronic device 100 is exemplified as a mobile phone. The electronic device 100 can include a screen 1, a frame 2, a back cover 3, a main circuit board 4, a secondary circuit board 5, a battery 6, and a sound generating device 7.

[0068] It can be understood that, Figure 1 and Figure 2 only schematically show some components included in the electronic device 100, and the actual shape, actual size, actual position, and actual structure of these components are not limited by Figure 1 and Figure 2 .

[0069] The screen 1 is used to display image information, video information, etc. The screen 1 includes a light-transmitting cover plate 11 and a display screen 12. The light-transmitting cover plate 11 is in the shape of a flat plate. Specifically, the shape of the light-transmitting cover plate 11 includes but is not limited to a rectangular flat plate, a square flat plate, an oblong flat plate, a circular flat plate, and an elliptical flat plate. The material of the light-transmitting cover plate 11 includes but is not limited to glass, plastic, and ceramic. The light-transmitting cover plate 11 and the display screen 12 are stacked and fixedly connected. The connection mode between the light-transmitting cover plate 11 and the display screen 12 includes but is not limited to adhesion. The light-transmitting cover plate 11 is mainly used to protect and prevent dust from the display screen 12.

[0070] The display screen 12 can be a flexible display screen or a rigid display screen. For example, the display screen 12 can be an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode (AMOLED) display screen, a mini organic light-emitting diode display screen, a micro organic light-emitting diode display screen, a micro organic light-emitting diode display screen, a quantum dot light emitting diode (QLED) display screen, or a liquid crystal display (LCD), etc.

[0071] The display surface of the display screen 12 faces the light-transmitting cover plate 11, so that the image, video, etc. displayed by the display screen 12 can be observed by the user through the light-transmitting cover plate 11.

[0072] For the convenience of the description of the embodiments below, an XYZ coordinate system is established for the electronic device 100. Specifically, the thickness direction of the electronic device 100 (i.e. the stacking direction of the light-transmitting cover plate 11 and the display screen 12) is defined as the Z-axis direction, the directions perpendicular to the Z-axis direction are defined as the X-axis direction and the Y-axis direction, and the X-axis direction and the Y-axis direction are perpendicular. Specifically, in this embodiment, the electronic device 100 is in the shape of a rectangular flat plate, wherein the length direction of the electronic device 100 is the Y-axis direction and the width direction of the electronic device 100 is the X-axis direction. It can be understood that the coordinate system of the electronic device 100 can be flexibly set according to actual needs, which is not specifically limited here.

[0073] The frame 2 is in the shape of a ring frame. The frame 2 surrounds the screen 1. The connection relationship between the frame 2 and the screen 1 includes but is not limited to adhesion, clamping, etc.

[0074] The frame 2 is provided with a middle plate 21. For example, the middle plate 21 and the frame 2 can be an integral structure. This is conducive to improving the structural strength of the shell and simplifying the processing technology of the shell and reducing the production cost of the shell. Of course, the present application is not limited to this, and in other examples, the frame 2 and the middle plate 21 can also be assembled, and the connection mode between the frame 2 and the middle plate 21 includes but is not limited to adhesion, clamping, screw connection and welding, etc.

[0075] The middle plate 21 is flat. The shape of the middle plate 21 is adapted to the shape of the light-transmitting cover plate 11. The middle plate 21 is located on the side of the display screen 12 away from the light-transmitting cover plate 11. The middle plate 21 serves as a structural "skeleton" of the electronic device 100, and the main circuit board 4, the auxiliary circuit board 5, the battery 6, and the like can be fixed to the middle plate 21.

[0076] Please continue to refer to Figure 2 The back cover 3 is flat. The shape of the back cover 3 includes, but is not limited to, a rectangular flat plate, an oblong flat plate, a circular flat plate, or an elliptical flat plate. Specifically, the shape of the back cover 3 is adapted to the shape of the light-transmitting cover plate 11. The material of the back cover 3 includes, but is not limited to, glass, plastic, metal, and ceramic.

[0077] The back cover 3 is located on the side of the middle plate 21 away from the screen 1, and is stacked with the middle plate 21 and the screen 1. The frame 2 is arranged around the periphery of the back cover 3 and is fixed to the back cover 3. In this way, the light-transmitting cover plate 11, the frame 2, and the back cover 3 can collectively enclose the shell of the electronic device 100.

[0078] For example, the frame 2 can be fixedly connected to the back cover 3 by means of adhesion, welding, or clamping, and the like. That is, the frame 2 and the back cover 3 can be assembled together.

[0079] Please refer to Figure 2 and Figure 3 , Figure 3 is a partial sectional view of the electronic device 100 shown in Figure 1 at the A-A line. The middle plate 21, the frame 2, and the back cover 3 enclose a first cavity Q of the electronic device 100. The first cavity Q can accommodate the main circuit board 4, the auxiliary circuit board 5, the battery 6, and the like.

[0080] The main circuit board 4 is located in the first cavity Q and is fixed to the middle plate 21. For example, the main circuit board 4 can be fixed to the middle plate 21 by means of threaded connection, clamping, adhesion, or welding, and the like. In some embodiments, the main circuit board 4 is electrically connected to the display screen 12, and the main circuit board 4 is used to control the display screen 12 to display images or videos.

[0081] The auxiliary circuit board 5 is located in the first cavity Q and is fixed to the middle plate 21. Specifically, the auxiliary circuit board 5 can be fixed to the surface of the middle plate 21 facing the back cover 3 by means of threaded connection, clamping, adhesion, or welding, and the like. The auxiliary circuit board 5 and the main circuit board 4 are arranged in the Y-axis direction.

[0082] The battery 6 is located in the first cavity Q. The battery 6 is located between the main circuit board 4 and the auxiliary circuit board 5. The battery 6 is used to provide power for the main circuit board 4, the auxiliary circuit board 5, the screen 1, and the sound generating device 7, and the like.

[0083] The battery 6 can include, but is not limited to, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium battery, or other types of batteries. Also, the number of the battery 6 in the embodiments of the present application can be multiple or one, and the specific number and arrangement of the battery 6 in the embodiments of the present application can be set according to actual needs.

[0084] The sound generating device 7 is configured to convert an audio electrical signal into a sound signal. The electronic device 100 is provided with a sound outlet 10, which is arranged at a gap between the frame 2 and the screen 1. The sound signal emitted by the sound generating device 7 can be transmitted to the outside of the electronic device 100 through the sound outlet 10. In some embodiments, the sound generating device 7 can be electrically connected to the main circuit board 4. The voice electrical signal sent by the main circuit board 4 is transmitted to the sound generating device 7, and is further converted into a sound signal by the sound generating device 7 for output.

[0085] The sound generating device 7 can be a receiver module, also known as a "earpiece", which can be used to listen to a voice when the electronic device 100 answers a phone call or a voice message. The sound generating device 7 can also be a speaker module, also known as a "loudspeaker", which can be used to listen to music or to listen to a hands-free call, so that the electronic device 100 can support sound output. The number of sound generating devices 7 can be multiple, and some of the multiple sound generating devices 7 can be receiver modules, and the other sound generating devices 7 can be speaker modules. Alternatively, all of the sound generating devices 7 can be speaker modules or receiver modules. In other embodiments, the number of sound generating devices 7 can also be one.

[0086] Please continue to refer to Figure 3 , the sound generating device 7 is installed in the housing. Specifically, the sound generating device 7 is fixed to the middle plate 21. The connection relationship between the sound generating device 7 and the middle plate 21 includes, but is not limited to, gluing, clamping, or screw connection.

[0087] The sound generating device 7 includes a shell 71 and a core 72.

[0088] It should be noted that Figure 3 only some components included in the sound generating device 7 are schematically shown, and the actual shape, actual size, actual position, and actual structure of these components are not limited by Figure 3 .

[0089] The shell 71 is configured to support and fix the core 72. Specifically, the core 72 is installed in the shell 71, and the core 72 blocks the side of the shell 71 facing the screen 1. The material of the shell 71 includes, but is not limited to, metal, plastic, or a combination of metal and plastic. Of course, it can be understood that in other examples, the sound generating device 7 can not include the shell 71, and only include the core 72.

[0090] Please refer to Figure 4 ,Figure 4 As shown in the electronic device shown in FIG. 1, the inner core 72 is a core component of the electronic device. The inner core 72 is located in the inner space of the outer shell 71. The inner core 72 is fixed in the outer shell 71 by the outer shell 71. The inner core 72 is located in the inner space of the outer shell 71. The inner core 72 is fixed in the outer shell 71 by the outer shell 71. Figure 3 As shown in the electronic device shown in FIG. 1, the inner core 72 is a core component of the electronic device. The inner core 72 is located in the inner space of the outer shell 71. The inner core 72 is fixed in the outer shell 71 by the outer shell 71. The inner core 72 is located in the inner space of the outer shell 71. The inner core 72 is fixed in the outer shell 71 by the outer shell 71.

[0091] The pot frame 721 serves as a "support skeleton" of the inner core 72, for supporting the diaphragm group 722, the voice coil 723, and fixing the magnetic circuit system 724. The material of the pot frame 721 includes but is not limited to metal, plastic, and a combination of the two. The inner core 72 can be fixed in the outer shell 71 by means of the pot frame 721.

[0092] The diaphragm group 722 includes a fixed part 7221, a folded ring 7222, and a ball top 7223. The fixed part 7221 is formed in the shape of a ring sheet. The fixed part 7221 is fixed in layers on the side of the pot frame 721 facing the screen 1. The connection mode of the fixed part 7221 and the pot frame 721 includes but is not limited to gluing, clamping, welding, or screw connection. The shape of the fixed part 7221 is adapted to the shape of the pot frame 721.

[0093] In some examples, the diaphragm group 722 is a one-piece molded part. That is, the fixed part 7221, the folded ring 7222, and the ball top 7223 are an integral structure. In this way, the structural strength of the diaphragm group 722 is improved, the structural stability of the diaphragm group 722 is improved, and the processing technology of the diaphragm group 722 is also simplified. Of course, the present application is not limited to this, the fixed part 7221, the folded ring 7222, and the ball top 7223 can also be independently molded parts, the fixed part 7221 and the folded ring 7222 can be connected by gluing, and the folded ring 7222 and the ball top 7223 can be connected by gluing. The material of the diaphragm group 722 includes but is not limited to metal, plastic, plant fiber, and animal fiber.

[0094] The voice coil 723 is located in the pot frame 721, one end of the voice coil 723 is connected to the surface of the ball top 7223 facing the inside of the pot frame 721. The connection mode between the voice coil 723 and the ball top 7223 includes but is not limited to gluing, clamping, welding, or screw connection. The voice coil 723 is generally in the shape of a ring frame. The voice coil 723 is used to cooperate with the magnetic circuit system 724 to synchronously drive the diaphragm group 722 to vibrate. Specifically, after the voice coil 723 is energized, an induced magnetic field can be generated, the magnetic circuit system 724 can respond to the induced magnetic field and exert a driving force on the voice coil 723, the voice coil 723 is driven by the magnetic force of the magnetic circuit system 724 to displace, thereby driving the diaphragm group 722 to vibrate.

[0095] The magnetic circuit system 724 is fixed on the end surface of the bracket 721 away from the fixed opening 711. The magnetic circuit system 724 has a ring-shaped magnetic gap 7241, and the part of the voice coil 723 away from the diaphragm group 722 can extend into the magnetic gap 7241, so that the magnetic circuit system 724 can cooperate with the voice coil 723 to drive the diaphragm group 722 to vibrate synchronously. It can be understood that in other embodiments, when the voice coil 723 is a planar voice coil 723, the voice coil 723 can also not extend into the magnetic gap 7241 described above. The planar voice coil 723 can be manufactured by winding or printed circuit.

[0096] On this basis, the sound generating device 7 has an acoustic cavity K. The acoustic cavity K includes a front cavity K1 and a rear cavity K2, wherein the side of the diaphragm group 722 facing the screen 1 forms the front cavity K1, and the front cavity K1 is in communication with the gap between the middle frame 2 and the display screen 12, forming an open front cavity. When the diaphragm group 722 vibrates, the magnetic circuit system 724 and the voice coil 723 jointly drive the diaphragm group 722 to vibrate, and the diaphragm group 722 can drive the air in the front cavity K1 to vibrate to generate sound, which is transmitted to the outside of the electronic device 100 through the sound hole 10.

[0097] The side of the diaphragm group 722 facing the back cover 3 forms the rear cavity K2. The side of the shell 71 facing the back cover 3 is open, so that the rear cavity K2 is in communication with the first cavity Q, forming an open rear cavity. The front cavity K1 and the rear cavity K2 of the sound generating device 7 are both open acoustic cavities in the examples described in this application.

[0098] It is worth noting that the foregoing is an example of the first cavity Q enclosed by the middle plate 21, the frame 2 and the back cover 3 as the expanded rear cavity of the sound generating device 7. In other embodiments, the first cavity Q enclosed by the display screen 12, the frame 2 and the middle plate 21 can also be used as the expanded rear cavity of the sound generating device 7, as long as the shell has the first cavity Q and the first cavity Q constitutes at least part of the rear cavity K2 of the sound generating device 7.

[0099] In order to ensure the sealing effect, the shell of the electronic device 100 is usually a closed cavity. In this way, when the sound generating device 7 works and the diaphragm group 722 vibrates, vibration sound waves will be generated in the rear cavity K2, and when the vibration sound waves reach the shell, they will drive the shell to resonate around the back cover 3, causing the electronic device 100 to vibrate when the sound generating device 7 generates sound, and causing noise during the sound generating process of the sound generating device 7, affecting the user's experience.

[0100] In order to solve the above technical problems, another electronic device 100 is provided in the present application. Please refer to Figure 5 and Figure 6 , Figure 5 the exploded view of another electronic device 100 is provided in the present application, Figure 6 the electronic device 100 according toFigure 5 A partial cross-sectional view of an electronic device 100 is shown, which is different from the electronic device 100 in the above embodiment in that the electronic device 100 comprises a sound insulation plate 8.

[0101] The sound insulation plate 8 is located in the first cavity Q and is fixed to the inner surface of the shell. For example, the inner surface of the shell can refer to the surface of the back cover 3 facing the middle plate 21, the surface of the frame 2 facing the middle plate 21, or both the surface of the back cover 3 facing the middle plate 21 and the surface of the frame 2 facing the middle plate 21. In this application, the inner surface of the shell is exemplarily illustrated as the surface of the back cover 3 facing the middle plate 21, but this does not constitute a special limitation to this application.

[0102] In this way, the sound insulation plate 8 plays a role of offsetting the vibration sound waves generated when the diaphragm group 722 vibrates to a certain extent, which is conducive to reducing the vibration sound waves transmitted to the shell to a certain extent, thereby weakening the vibration of the shell, realizing the damping function of the sound insulation plate 8 to the shell, and improving the user experience.

[0103] It is worth noting that due to the limited space of the rear cavity K2, in the Z-axis direction (i.e. the thickness direction of the electronic device 100), the thickness of the sound insulation plate 8 should be smaller than the distance from the inner surface of the back cover 3 to the battery 6, so as to reserve a certain space for the rear cavity K2 of the electronic device 100 and ensure the low-frequency performance of the electronic device 100. At the same time, in order to reduce the influence of the thickness of the sound insulation plate 8 on the overall thickness of the electronic device 100, the thickness of the sound insulation plate 8 can be adjusted according to the thickness of the electronic device 100.

[0104] The structure and damping principle of the sound insulation plate 8 will be introduced in detail below.

[0105] Please refer to Figure 7 and Figure 8 , Figure 7 for Figure 5 a schematic view of the sound insulation plate 8 in the electronic device 100 shown, Figure 8 for a structural schematic view of the sound insulation unit 81 in the sound insulation plate 8 shown in Figure 7 The sound insulation plate 8 comprises at least one sound insulation unit 81. That is, in the sound insulation plate 8, the sound insulation unit 81 can be one or more.

[0106] The sound insulation unit 81 comprises a flexible film 811, a mass block 812, and an annular frame 813.

[0107] The side of the flexible film 811 in the thickness direction is a first surface 8111, and the first surface 8111 of the flexible film 811 faces the back cover 3. Exemplarily, the material of the flexible film 811 includes but is not limited to rubber, silicone, or a resin film (for example, a polyimide film). Moreover, the shape of the flexible film 811 includes but is not limited to a circle, a semicircle, a racetrack shape, a waist-round polygon, or a special shape.

[0108] The mass block 812 is located at the center of the first surface 8111 of the flexible film 811 and is fixed to the flexible film 811. Exemplarily, the fixing mode of the flexible film 811 and the mass block 812 includes but is not limited to gluing, clamping, riveting, welding, or screwing, etc.

[0109] In some examples, the material of the mass block 812 can be metal, such as stainless steel or iron, etc. Moreover, the shape of the mass block 812 includes but is not limited to a circle, a semicircle, a racetrack shape, a waist-round polygon, or a special shape. In this way, based on the fact that the rigidity of metal is greater than the rigidity of the flexible film 811, the flexible film 811 can be counterweighted by the mass block 812 during the vibration reduction process to control the surface tension of the flexible film 811.

[0110] Moreover, the mass block 812 is located within the annular frame 813, and the annular frame 813 is fixed to the outer peripheral edge of the first surface 8111 of the flexible film 811. The flexible film 811 and the mass block 812 are spaced apart from the back cover 3 by the annular frame 813. In this way, on the one hand, the annular frame 813 can prevent the flexible film 811 from contacting the back cover 3 when the flexible film 811 vibrates, thereby improving the sound insulation and vibration reduction performance of the sound insulation panel 8. On the other hand, since the flexible film 811 is soft and has the characteristic of being easily deformed, in order to prevent the flexible film 811 from deforming during the vibration reduction process, the annular frame 813 can support the flexible film 811.

[0111] The shape of the annular frame 813 includes but is not limited to a circular ring, an elliptical ring, a semicircular ring, a rectangular ring, or a special-shaped ring. In this way, the annular frame 813 has a simple structure and is easy to manufacture. The material of the annular frame 813 includes but is not limited to metal, carbon fiber, or resin, etc.

[0112] In addition, the adjacent annular frames 813 can be glued, clamped, or screwed, etc. Alternatively, the adjacent annular frames 813 can be integrally formed, and the side walls of any two adjacent annular frames 813 are connected together, that is, the adjacent two annular frames 813 share part of the side walls, and the part of the side walls shared by the adjacent two annular frames 813 can form a connecting arm. For example, in the case where the cross section (parallel to the XY plane) of the annular frame is a square, the adjacent two annular frames 813 share one side of the square, that is, the two annular frames 813 share one side wall.

[0113] In order to distinguish two adjacent annular frames 813, the connecting arm can be bisected and formed into two parts, Figure 8 The dashed line marks the boundary between the two annular frames 813, and the two parts are arranged in the arrangement direction of the two sound insulation units 81, one of the two parts belongs to one annular frame 813, and the other of the two parts belongs to another annular frame 813. Hereinafter, the same understanding can be made for the flexible film 811, and details are not repeated.

[0114] Exemplarily, the plurality of annular frames 813 can be formed into an integral part by punching, powder injection and the like. Of course, in other embodiments, any two adjacent annular frames 813 in the plurality of annular frames 813 can also be fixed together by welding, gluing, clamping or screw connection and the like.

[0115] In some embodiments, please refer to Figure 9 , Figure 9 According to Figure 5 The cross-sectional schematic diagram of one connection mode of the sound insulation plate 8 and the back cover 3 of the electronic device 100 is shown, in order to further ensure the sound insulation and vibration reduction effect of the sound insulation plate 8, the annular frame 813 and the back cover 3 can be provided with an elastic material layer T. The sound insulation plate 8 is spaced apart from the back cover 3 by the elastic material layer T. The connection mode between the elastic material layer T and the back cover 3 includes but is not limited to gluing, and the connection mode between the elastic material layer T and the annular frame 813 includes but is not limited to gluing.

[0116] In this way, since the elastic material layer T has a damping property, the elastic material layer T is arranged between the sound insulation plate 8 and the back cover 3, which is beneficial to further utilize the damping property of the elastic material layer T to absorb part of the energy of the sound wave, and can further prevent the vibration of the sound insulation plate 8 from being transmitted to the back cover 3, thereby increasing a vibration reduction barrier between the sound insulation plate 8 and the back cover 3 and improving the vibration reduction effect.

[0117] Exemplarily, the material of the elastic material layer T includes but is not limited to a rubber part or a silica gel part and the like.

[0118] Of course, in other embodiments, the annular frame 813 and the back cover 3 can also not be provided with the elastic material layer T, and the annular frame 813 and the back cover 3 are connected by gluing, clamping or screw connection.

[0119] Please refer to Figure 10 , and also refer to Figure 6 . Figure 10Vibration displacement nephogram of the sound insulation unit 81. It needs to be explained that in the embodiments of the present application, the sound insulation plate 8 utilizes the morphological characteristics of acoustic metamaterials to realize local resonance to sound insulation and vibration reduction of the electronic device 100. Specifically, when the diaphragm group 722 vibrates, the air in the rear cavity K2 generates vibration sound waves due to vibration, which are transmitted to the flexible film 811 and the mass block 812 of the sound insulation plate 8. When the sound waves are incident on the sound insulation plate 8, the mass block 812 will drive the flexible film 811 to vibrate, and the flexible film 811 will generate surface tension with the mass block 812 to control the vibration of the mass block 812 in the vibration state. As long as the incident frequency of the sound wave and the resonance frequency of the mass block 812 on the flexible film 811 are matched, the central region of the sound insulation plate 8 (i.e. the mass block 812) and the edge region of the sound insulation plate 8 (i.e. the flexible film 811) are in opposite phase resonance to inhibit sound propagation, and therefore the responses of the mass block 812 and the flexible film 811 to the sound waves in the transmission direction of the sound waves are different, so that the displacement of the vibration of the flexible film 811 (the dashed arrow in the figure indicates the vibration direction of the flexible film 811) and the displacement direction of the vibration of the mass block 812 (the dashed arrow in the figure indicates the vibration direction of the flexible film 811) are opposite. In this way, the displacement of the vibration of the flexible film 811 and the mass block 812 can be offset to a certain extent or completely offset, so that the displacement of the entire sound insulation plate 8 tends to be or is equal to 0mm. Therefore, the sound insulation plate 8 can intercept and block the vibration sound waves generated by the vibration of the diaphragm group 722 to a certain extent, which is conducive to reducing the vibration sound waves transmitted to the shell to a certain extent, thereby weakening the vibration of the shell, realizing the vibration reduction function of the sound insulation plate 8 to the shell, and improving the user experience. Figure 10 Figure 10

[0120] Of course, the present application is not limited thereto, and in other embodiments, the plurality of sound insulation units 81 can also be distributed in a ring array.

[0121] In some examples, the plurality of sound insulation units 81 are arranged on the plane where the first surface 8111 is located, and the flexible films 811 of any two adjacent sound insulation units 81 are connected together.

[0122]

[0123] ​​​In this way, on the one hand, by arranging multiple sound insulation units 81 on the sound insulation plate 8, the number of flexible membranes 811 and mass blocks 812 is increased, and the sound insulation and vibration reduction effect of the sound insulation plate 8 is improved. On the other hand, by connecting the annular frames 813 of two adjacent sound insulation units 81 on the sound insulation plate 8 together, the structural strength of the sound insulation plate 8 is improved.

[0124] In some other examples, the multiple annular frames 813 can be connected as one, i.e., the multiple annular frames 813 are integrally formed. In this way, it is beneficial to improve the structural strength of the sound insulation plate 8, simplify the processing process of the sound insulation plate 8, and reduce the manufacturing cost.

[0125] In order to further exert the sound insulation and vibration reduction performance of the sound insulation plate, the outer shape of the sound insulation plate 8 can be adapted to the outer shape of the back cover 3. In this way, it is beneficial to weaken the vibration of the back cover 3, thereby further weakening the vibration of the back cover 3 and improving the user's experience.

[0126] For example, the outer contour of the sound insulation plate 8 includes but is not limited to a square, a rectangle, a circle, an ellipse, or a special shape.

[0127] Regarding the vibration reduction effect of the sound insulation plate 8 on different positions on the back cover 3, experiments were conducted. Please refer to Figure 11 , Figure 11 The test schematic diagram of the vibration position of the sound insulation plate 8 on the back cover 3 is shown, wherein Figure 11 The positions a, b, c, d, and X are shown in

[0128] An experimental group and a control group were set up for this test, respectively. The experimental group is: the sound insulation plate 8 described above is installed at position X, and the vibration degree of positions X, a, b, c, and d on the back cover 3 during the vibration process of the diaphragm group 722 of the sound generating device 7 is tested. The control group is: the sound insulation plate 8 described above is not installed at position X, and the vibration degree of positions X, a, b, c, and d during the vibration process of the diaphragm group 722 of the sound generating device 7 is tested.

[0129] Please refer to Figure 12 and Figure 13 , Figure 12 The simulation test results of the vibration acceleration level of the position X on the back cover 3 of the experimental group and the back cover 3 of the control group are shown in Figure 11 ; Figure 13 The simulation test results of the vibration acceleration level of the position a on the back cover 3 of the experimental group and the control group are shown in Figure 11 ; the test results are shown in Table 1.

[0130] Table 1

[0131] Position Position X Position a Position b Position c Position d Control group 146 dB 155 dB 158 dB 162 dB 155 dB Experimental group 142 dB 151 dB 157 dB 162 dB 154 dB

[0132] From Figure 12 and Figure 13 and the test data in Table 1, it can be seen that, based on the long distance between the positions b, c, d and the position X, the vibration degree at the positions b, c, d does not change significantly when the sound insulation board 8 is installed at the position X or not installed at the position X.

[0133] The vibration acceleration level of the back cover 3 in the control group at the position X is 146 dB, and the vibration acceleration level of the experimental group is 142 dB. The parameter of the experimental group is obviously smaller than that of the control group, that is, the sound insulation board 8 arranged at the position X plays a role in reducing the vibration of the back cover 3.

[0134] The vibration acceleration level of the back cover 3 in the control group at the position a is 155 dB, and the vibration acceleration level of the experimental group is 151 dB. The vibration acceleration level of the back cover 3 in the experimental group is obviously smaller than that of the back cover 3 in the control group. That is, the sound insulation board 8 arranged at the position X plays a role in reducing the vibration of the back cover 3 at the position a.

[0135] From the above experiment, it can be concluded that the sound insulation board 8 can reduce the vibration transmitted by the sound generating device 7 to the back cover 3, and the closer the position of the sound insulation board 8 to the sound generating device 7, the better the sound insulation effect.

[0136] Based on the above experiment, in some embodiments of the present application, the vertical projection of the sound generating device 7 on the back cover 3 overlaps with the vertical projection of the sound insulation board 8 on the back cover 3. For example, the vertical projection of the sound insulation board 8 on the back cover 3 can completely cover the vertical projection of the sound generating device 7 on the back cover 3, or the vertical projections of the two on the back cover 3 can partially overlap each other.

[0137] The closer the distance to the diaphragm group 722, the stronger the vibration amplitude of the vibration sound wave. The area on the back cover 3 directly opposite the sound generating device 7 is relatively close to the sound generating device 7, and the vibration amplitude at this position is often relatively large. Therefore, by overlapping the vertical projection of the sound generating device 7 on the back cover 3 with the vertical projection of the sound insulation board 8 on the back cover 3, the vibration sound wave at this position can be intercepted and blocked to a certain extent by the sound insulation board 8, the vibration amplitude of the back cover 3 at this position can be reduced, and the vibration reduction effect of the back cover 3 can be improved.

[0138] In addition, the vertical projection of the sound insulation plate 8 covers the center of the side surface of the back cover 3 facing the middle plate 21. Specifically, since the edges of the back cover 3 are fixed with the frame 2, the remaining part of the back cover 3 is in a suspended state. Therefore, when the sound generating device 7 is working, the vibration amplitude at the central area of the back cover 3 is often larger. Therefore, by making the vertical projection of the sound insulation plate 8 cover the center of the side surface of the back cover 3 facing the middle plate 21, the vibration sound waves at this position can be intercepted and blocked to a certain extent by the sound insulation plate 8, the vibration amplitude of the back cover 3 at this position is reduced, and the vibration reduction effect of the back cover 3 is improved.

[0139] The control factor for realizing the sound insulation and vibration reduction function of the sound insulation plate 8 is the sound insulation amount of the sound insulation plate 8, which is an important parameter for measuring the sound insulation effect. It can be understood that the higher the sound insulation amount, the better the sound insulation effect of the sound insulation plate 8. In order to make the sound insulation plate 8 achieve better sound insulation and vibration reduction effect, based on the structure of the sound insulation plate 8 and the principle of local resonance, the sum of the sound insulation amounts of the sound insulation units 81 is the sound insulation amount of the sound insulation plate 8 in the sound insulation plate 8 of the present application. On the basis of any of the above embodiments, the sound insulation amount of the sound insulation unit 81 is greater than or equal to 40 dB.

[0140] For example, the sound insulation amount of the sound insulation unit 81 can be 40 dB, 50 dB, 53 dB, 55 dB, 60 dB, 65 dB, 68 dB, 70 dB, 75 dB, 78 dB, 80 dB, 85 dB, 90 dB, 95 dB or 98 dB.

[0141] In some embodiments, when the sound insulation plate 8 includes a plurality of sound insulation units 81, the plurality of sound insulation units 81 can be arranged in the direction in which the first surface 8111 is located, and the flexible film 811 of any two adjacent sound insulation units 81 is connected together.

[0142] In this way, on the one hand, based on the fact that the sound insulation amount of the sound insulation plate 8 is the sum of the sound insulation amounts of the sound insulation units 81, by providing a plurality of sound insulation units 81 on the sound insulation plate 8, the number of sound insulation units 81 is increased, and thus the sound insulation and vibration reduction effect of the sound insulation plate 8 is improved; on the other hand, by connecting the flexible films 811 of the two adjacent sound insulation units 81 on the sound insulation plate 8 together, the area of the flexible film 811 is increased, and thus the structural strength of the sound insulation plate 8 is improved.

[0143] The measurement method of the sound insulation amount of the sound insulation unit 81 includes but is not limited to reverberation chamber method, transfer chamber method, acoustic impedance tube method, sound insulation chamber method, acoustic camera method, sound transmission method and sensor measurement method, etc.

[0144] As an example of the reverberation chamber method, when measuring the sound insulation amount of the sound insulation unit 81, a standard reverberation chamber is first selected to ensure that the acoustic characteristics of the room meet the standard requirements. The sound source, sound level meter, analyzer and other equipment are prepared and calibrated. Then, the sound insulation unit 81 is installed at the test opening of the reverberation chamber, ensuring that it is firmly installed and has no gaps. Standardized white noise or pink noise is generated in the reverberation chamber to ensure that the noise signal covers the required frequency range. Then, the sound pressure level of the noise signal is measured at different positions in the reverberation chamber, and the data is recorded. Finally, according to the spectrum analysis results, the average sound insulation amount of the sound insulation unit 81 is calculated to obtain the sound insulation amount of the sound insulation board 8.

[0145] As an example of the transfer chamber method, when measuring the sound insulation amount of the sound insulation unit 81, two adjacent standard test chambers are first selected, one as a source chamber and the other as a receiving chamber. Next, the sound source, sound level meter, analyzer and other equipment are prepared and calibrated. Then, the sound insulation unit 81 is installed at the opening between the two test chambers, ensuring that it is firmly installed and has no gaps. Standardized white noise or pink noise is generated in the sound source chamber to ensure that the noise signal covers the required frequency range. Then, the sound pressure level of the noise signal is measured at different positions in the sound source chamber and the receiving chamber, and the data is recorded. Finally, according to the spectrum analysis results, the average sound insulation amount of the sound insulation unit 81 is calculated to obtain the sound insulation amount of the sound insulation board 8.

[0146] In general, the sound generating device 7 of the electronic device 100 is a full-band sound generating unit, and the vibration frequency range of the sound generating device 7 is generally 100Hz-20KHz. The vibration sound waves generated by the vibration of the diaphragm group 722 are transmitted to the back cover 3, which is also a full-band. However, through actual verification, for the perception of the human body, the human body has obvious perception of the vibration transmission of the vibration frequency below 500Hz, and is not sensitive to the vibration transmission of the vibration frequency above 500Hz. That is, the human body can obviously perceive the vibration sensation brought by the frequency below 500Hz. In the present application, when the vibration frequency is below 500Hz, the vibration sound waves generated by the vibration of the diaphragm group 722 transmitted to the back cover 3 can be obviously perceived by the human body. Based on this, in some embodiments of the present application, the resonance frequency f of the sound insulation unit 81 is less than or equal to 500Hz. In this way, the sound insulation board 8 intercepts or blocks the vibration sound waves below 500Hz generated by the vibration of the diaphragm group 722 to a certain extent, which is beneficial to at least reduce the vibration sound waves transmitted to the shell to a certain extent, thereby weakening the vibration of the shell, realizing the vibration reduction function of the sound insulation board 8 to the shell, and improving the user experience.

[0147] In the actual test process, the resonance frequency of the sound insulation unit 81 and the sound generating device 7 can be tested by an electro-acoustic tester.

[0148] On this basis, the sound damping performance of the acoustic metamaterial applied to the soundproof panel 8 of the present application is analyzed. Please refer to Figure 14 , Figure 14 Figure 8 is a schematic diagram of the vibration mode of the soundproof panel 8 in the full frequency band. In the simulation process, a soundproof peak fp and two soundproof valleys fd1 and fd2 are generated. When the frequency is less than fd1, the effective mass of the mass block 812 and the flexible film 811 increases from negative infinity, and the soundproof performance decreases, that is, the soundproof amount of the soundproof panel 8 presents a downward trend.

[0149] When the frequency is fp, the subsystem composed of the equivalent stiffness K1 of the mass block 812 and the flexible film 811 is anti-resonance, the effective mass of the mass block 812 and the flexible film 811 approaches infinity, and the soundproof performance improves.

[0150] When the frequency is between fp and fd2, the soundproof performance decreases, that is, the soundproof amount of the soundproof panel 8 presents a downward trend.

[0151] When the frequency is fd1 and fd2, the soundproof amount of the soundproof panel 8 approaches 0, the effective mass of the mass block 812 and the flexible film 811 approaches 0, the soundproof panel 8 presents a resonance mode, and the soundproof performance decreases. Resonance mode refers to when the frequency of the excitation received by the object is the same as or close to the natural frequency of the object, the amplitude of the object will significantly increase, and resonance phenomenon will occur.

[0152] Please refer to Figure 15 , Figure 15 Figure 15 is a vibration displacement cloud diagram of the soundproof panel 8 at the soundproof valley fd1. The vibration frequency corresponding to the soundproof valley fd1 approaches 200 Hz, the soundproof valley fd1 corresponds to the vibration of the center of the soundproof panel 8 (the mass block 812 region), the 15 dotted arrow in the figure marks the direction of the vibration of the soundproof panel 8, and only the center region (i.e. the mass block 812 region) presents a vibration state at present, the edge region (i.e. the flexible film 811 region) does not produce displacement or has a small displacement, the vibration displacement of the mass block 812 and the vibration displacement of the flexible film 811 cannot be offset, and the soundproof amount of the soundproof panel 8 presents a downward trend, so the soundproof damping performance of the soundproof panel 8 at the soundproof valley fd1 is not obvious.

[0153] Please refer to Figure 16 , Figure 16 Figure 16 is a vibration displacement cloud diagram of the soundproof panel 8 at the soundproof valley fd2. The vibration frequency corresponding to the soundproof valley fd2 approaches 3000 Hz, fd2 corresponds to the vibration mode of the edge region of the soundproof panel 8 (i.e. the flexible film 811 region), Figure 16The center dotted arrow marks the vibration direction of the sound insulation plate 8. The vibration mode of the central area (i.e., the area of the mass block 812) is not obvious, the vibration displacement of the mass block 812 cannot be offset with the vibration displacement of the flexible film 811, and the sound insulation amount of the sound insulation plate 8 shows a downward trend, so the sound insulation damping performance of the sound insulation plate 8 at the sound insulation valley fd2 is not obvious.

[0154] Please refer to Figure 17 , Figure 17 is a vibration displacement cloud diagram of the sound insulation plate 8 at the sound insulation peak fp. The frequency corresponding to the sound insulation peak fp is about 500 Hz. The sound insulation peak fp is the fusion of fd1 and fd2. Figure 17 The center dotted arrow marks the vibration direction of the sound insulation plate 8. The vibration mode of the central area (i.e., the area of the mass block 812) is opposite to the vibration mode of the edge area (i.e., the area of the flexible film 811), and at the low-frequency anti-resonance frequency, the sound wave is almost fully reflected, so there is a significant sound insulation peak at the low frequency, so the sound insulation damping performance of the sound insulation plate 8 at the sound insulation peak fp is improved.

[0155] From the above simulation experiment, it can be concluded that the human body can obviously feel the vibration sensation caused by frequencies below 500 Hz, and when the sound insulation peak fp reaches about 500 Hz, the sound insulation amount of the sound insulation plate 8 is more than 40 dB. Therefore, through simulation verification, the sound insulation plate 8 provided by the embodiment of the present application can offset or completely offset the vibration sensation of the diaphragm group 722 caused by frequencies below 500 Hz, and the sound insulation plate 8 can play a role in sound insulation and vibration damping for the shell.

[0156] When the sound wave excitation frequency approaches the natural frequency F, resonance occurs. At this time, the metamaterial has anti-resonance phenomenon, and the sound insulation effect is most significant at this time, so the natural frequency F is the sound insulation peak frequency of the metamaterial. The formula of the natural frequency F is shown in the following formula one:

[0157]

[0158] Wherein, Dp is the bending stiffness of the flexible film 811, m2 is the mass of the mass block 812, Rp is the equivalent radius of the flexible film 811, and Rm is the equivalent radius of the mass block 812.

[0159] Please refer to Figure 18 , Figure 18 is a sound insulation curve diagram of the sound insulation amount of the sound insulation plate 8 and the frequency relationship of the sound insulation plate 8 with different equivalent radii Rm of the mass block 812. Through simulation experiment, it is obtained that when the resonance frequency f of the sound insulation unit 81 is less than or equal to 500 Hz, the equivalent radius Rm of the mass block 812 is greater than or equal to 0.8e -3 m, and less than or equal to 1.2e -3m, a sound insulation greater than 40dB can be achieved. In this way, increasing the radius of mass block 812 within a certain range will cause the overall frequency sound insulation valley fd1, sound insulation peak fp, and sound insulation valley fd2 to move upward, increasing the sound insulation, thereby facilitating the low-frequency sound insulation and vibration reduction performance of the sound insulation unit 81.

[0160] The formula for the bending stiffness Dp of the flexible film 811 is shown in the following formula 2:

[0161]

[0162] Wherein, E is the Young's modulus of the flexible film 811 , h is the thickness of the flexible film 811 , and μ is the Poisson's ratio of the flexible film 811 .

[0163] See also Figure 19 , Figure 19 The following is a sound insulation curve showing the relationship between the sound insulation performance and frequency of the sound insulation board 8 with different Young's modulus E values ​​of the flexible film 811. The modulus of the flexible film 811 was obtained through simulation experiments. When the resonant frequency f of the sound insulation unit 81 is less than or equal to 500 Hz, the Young's modulus E of the flexible film 811 is greater than or equal to e 9 Pa, and less than or equal to 9e 9 Pa, achieving a sound insulation greater than 40dB. Thus, by increasing the Young's modulus E of the flexible film 811 within a certain range, the bending stiffness Dp can be equivalently increased, thereby increasing the peak value fp and bandwidth, thereby increasing the sound insulation, and further facilitating the low-frequency sound insulation and vibration reduction function of the sound insulation unit 81.

[0164] Combining Formula 2, it can be seen that the thickness h of the flexible film 811 is positively correlated with the flexural stiffness Dp. Within a certain range, increasing the thickness h of the flexible film 811 can effectively increase the flexural stiffness Dp, thereby increasing the peak value fp and bandwidth, thereby increasing the sound insulation, and thus facilitating the low-frequency sound insulation and vibration reduction function of the sound insulation unit 81. To ensure that the sound insulation panel 8 achieves optimal sound insulation, the thickness h of the flexible film 811 is less than or equal to 1 mm.

[0165] Illustratively, the thickness h of the flexible film 811 may be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0166] During the vibration of the diaphragm group 722, the mass block 812 and the flexible film 811 vibrate, and the flexible film 811 generates a tension force to propagate the vibration by using the elastic properties of the flexible film 811 itself. Therefore, the tension force of the flexible film 811 is also one of the important factors in the sound insulation and vibration reduction process of the sound insulation plate 8. Based on this, a simulation experiment is performed to determine whether the tension force of the flexible film 811 has a benefit for vibration reduction. Please refer to Figure 20 , Figure 20 FIG. 6 is a curve diagram of the vibration displacement of the back cover 3 obtained by simulating the tension force of the flexible film 811. In FIG. 6, the dashed line represents the vibration displacement curve of the back cover 3 when the flexible film 811 in the sound insulation plate 8 has no tension force (i.e., the flexible film 811 has no elasticity). Figure 20 From the dashed line curve in FIG. 6, it can be found that a high displacement peak value appears when the flexible film 811 in the sound insulation plate 8 has no tension force. That is, the back cover 3 vibrates and the vibration displacement is large when the flexible film 811 in the sound insulation plate 8 has no tension force. Figure 20 The solid line in FIG. 6 represents the vibration displacement curve of the back cover 3 when the flexible film in the sound insulation plate 8 has a tension force, and the tension force of the flexible film 811 is 40 MPa. Figure 20 From the solid line curve in FIG. 6, it can be found that two smaller displacement peak values and a lower displacement trough appear when the flexible film 811 in the sound insulation plate 8 has a tension force. Compared with the state of the flexible film 811 in the sound insulation plate 8 having no tension force, when the flexible film 811 in the sound insulation plate 8 has a tension force, the high displacement peak value in the state of the flexible film 811 in the sound insulation plate 8 having no tension force is dispersed into two smaller displacement peak values, and a displacement trough appears when the flexible film 811 in the sound insulation plate 8 has a tension force. That is, the displacement of the back cover 3 is significantly reduced and tends to be 0 mm at the displacement trough. From the curve diagram of the above simulation experiment, it can be known that the tension force of the flexible film 811 changes the resonance frequency of the flexible film. The displacement peak value at 1400 Hz corresponds to the resonance frequency of the back cover 3. Changing the tension force can adjust the dipole resonance frequency, thereby reducing the resonance displacement of the back cover 3. Therefore, the tension force of the flexible film 811 in the sound insulation plate 8 can reduce the vibration displacement of the back cover 3. Figure 20 Based on the above experiment, in order to further play the role of the tension force of the flexible film 811 in the sound insulation and vibration reduction process of the sound insulation plate 8, and further ensure the vibration reduction performance of the electronic device 100, in some embodiments, the tension force of the flexible film 811 is less than or equal to 200 MPa, so as to ensure the sound insulation and vibration reduction performance of the flexible film 811.

[0167]

[0168] ​For example, the tension of the flexible film 811 can be 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 80 MPa, 90 MPa, 100 MPa, 120 MPa, 140 MPa, 160 MPa, 180 MPa or 200 MPa, etc.

[0169] In some other embodiments of the present application, a sealed cavity K is formed between the flexible film 811, the annular frame 813 and the back cover 3, and the sealed cavity K is filled with a first gas, which has a different density from air.

[0170] In some examples, the first gas can have a density greater than that of air, such as helium, etc.; or the first gas can also have a density greater than that of air, such as carbon dioxide, etc.

[0171] Please refer to Figure 21 , Figure 21 a graph of the vibration displacement of the back cover 3 when different gases are filled in the sound insulation unit 81, and the vibration displacement of the back cover when filled with helium, air and carbon dioxide is less than that when filled with air, that is, the amplitude of the vibration of the back cover 3 tends to decrease when filled with helium and carbon dioxide. In this way, by filling the sealed cavity K with a first gas having a different density from air outside the sealed cavity K, a pressure difference is formed between the sealed cavity K and the air, and the sound insulation and vibration reduction performance of the sound insulation panel 8 on the back cover 3 is achieved.

[0172] In the description of the present application, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0173] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electronic device, comprising: The application relates to a sound production device, comprising: a shell with a first cavity in the shell; a sound production device mounted in the shell, the first cavity constituting at least part of a back cavity of the sound production device; a sound insulation plate in the first cavity, the sound insulation plate comprising at least one sound insulation unit, the sound insulation unit comprising a flexible film, a mass and a ring-shaped frame, one side surface of the flexible film in the thickness direction being a first surface, the mass and the ring-shaped frame being fixed to the flexible film, the mass being in the ring-shaped frame and at the center of the first surface.

2. The electronic device of claim 1, wherein, The sound insulation amount of the sound insulation unit is greater than or equal to 40 dB.

3. The electronic device of claim 1, wherein, The sound insulation plate comprises a plurality of sound insulation units arranged in the direction of the first surface, and the flexible films of any two adjacent sound insulation units are connected together.

4. The electronic device of claim 3, wherein, The plurality of sound insulation units are arranged in a rectangular array.

5. The electronic device of any of claims 1-4, wherein, The plurality of sound insulation units are arranged in the plane of the first surface, and the flexible films of the plurality of sound insulation units are connected together; and / or, The plurality of ring-shaped frames are connected together.

6. The electronic device of claim 5, wherein, An elastic material layer is arranged between the ring-shaped frame and the inner surface of the shell.

7. The electronic device of any of claims 1-6, wherein, A sealed cavity is formed between the flexible film, the ring-shaped frame and the inner surface of the shell, and the sealed cavity is filled with a first gas; the first gas has a different density from air.

8. The electronic device of any of claims 1-7, wherein, The Young's modulus of the flexible film is E, the E is greater than or equal to e 9 Pa, and less than or equal to 9e 9 Pa.

9. The electronic device of any of claims 1-8, wherein, The radius Rm of the mass is greater than or equal to 0.8e -3 m, and less than or equal to 1.2e -3 m.

10. The electronic device of any of claims 1-9, wherein, The resonance frequency of the sound insulation unit is f, and the f is less than or equal to 500 Hz.

11. The electronic device of any of claims 1-10, wherein, The mass is made of metal.

12. The electronic device of any of claims 1-11, wherein, The shell comprises a back cover, a frame and a middle plate, the middle plate is arranged in layers with the back cover, the middle plate is fixed in the frame, the back cover is arranged on one side of the frame and is fixedly connected with the frame, the sound production device is fixed to the middle plate, the middle plate, the frame and the back cover enclose the first cavity, and the sound insulation plate is fixed to the surface of the back cover facing the middle plate.

13. The electronic device of claim 12, wherein, The vertical projection of the sound production device on the back cover overlaps the vertical projection of the sound insulation plate on the back cover.

Images