Electronic device and sound control method thereof

Abstract

The present invention discloses an electronic device and a sound control method thereof, the electronic device comprises a shell and two piezoelectric actuators, the shell comprises a screen, a rear shell and a middle shell connecting the screen and the rear shell, the screen and the middle shell enclose a first sealed fixed cavity, the rear shell and the middle shell enclose a second sealed fixed cavity; the two piezoelectric actuators are respectively installed in the first fixed cavity and the second fixed cavity, one of the piezoelectric actuators receives excitation to drive the screen to vibrate and emit a first sound wave; the other piezoelectric actuator receives excitation to drive the rear shell to vibrate and emit a second sound wave, the first sound wave and the second sound wave have opposite phases. The electronic device of the technical solution of the present invention can effectively improve the problem of sound leakage during calls.

Description

Technical Field

[0001] The present invention relates to the field of sound generation technology, and in particular to an electronic device and a sound generation control method thereof. Background Art

[0002] When using electronic devices, content privacy has always been a concern for users, for example, the privacy of calls on mobile terminals. With the accelerated pace of life, it is often necessary to answer calls in relatively quiet public places such as elevators or offices. The structure of existing mobile terminals generally has a dynamic sound unit installed in the shell. The sound emitted by the handset can be heard by the user and the people around him clearly, which may lead to the problem of leaking the content of the call. Summary of the invention

[0003] The main purpose of the present invention is to provide an electronic device, aiming to solve the problem of call leakage of the electronic device.

[0004] To achieve the above object, the electronic device proposed by the present invention includes:

[0005] A housing, the housing comprising a screen, a rear housing, and a middle housing connecting the screen and the rear housing, the screen and the middle housing forming a sealed first fixed cavity, and the rear housing and the middle housing forming a sealed second fixed cavity; and

[0006] Two piezoelectric actuators are respectively installed in a first fixed cavity and a second fixed cavity. One of the piezoelectric actuators receives excitation to drive the screen to vibrate and emit a first sound wave; the other piezoelectric actuator receives excitation to drive the back shell to vibrate and emit a second sound wave. The first sound wave and the second sound wave are in opposite phases.

[0007] Optionally, a first fixing groove is formed on a surface of the middle shell facing the screen, and the screen covers the first fixing groove to enclose the first fixing cavity; a second fixing groove is formed on a surface of the middle shell facing the rear shell, and the rear shell covers the second fixing groove to enclose the second fixing cavity;

[0008] The two fixing parts of the two piezoelectric actuators are respectively fixed in the first fixing groove and the second fixing groove, and the two deformation parts of the two piezoelectric actuators are respectively facing the screen and the rear shell.

[0009] Optionally, the deformation portion of one piezoelectric actuator is spaced apart from the screen, and the deformation portion of another piezoelectric actuator is spaced apart from the rear shell.

[0010] Optionally, the piezoelectric actuator is connected to the middle shell by bonding.

[0011] Optionally, projections of the two piezoelectric actuators on the middle shell at least partially overlap.

[0012] Optionally, the two piezoelectric actuators are both arranged close to the upper end of the screen.

[0013] Optionally, the two piezoelectric actuators are both located in the middle of the screen in the width direction.

[0014] Optionally, the electronic device further includes a controller, which is disposed in the housing and electrically connected to both of the piezoelectric actuators to send an excitation signal.

[0015] Optionally, the electronic device is a mobile phone.

[0016] The present invention also provides a method for controlling the sound of an electronic device, the method comprising the steps of:

[0017] determining an operating mode of the electronic device;

[0018] When the electronic device is in the handset mode, the piezoelectric actuator close to the screen is controlled to receive stimulation and emit a first sound wave, and the other piezoelectric actuator is controlled to emit a second sound wave with a phase opposite to the first sound wave;

[0019] When the electronic device is in a speaker mode, the piezoelectric actuator close to the screen is controlled to receive stimulation and emit a first sound wave, and the other piezoelectric actuator is controlled to emit a third sound wave with the same phase as the first sound wave.

[0020] The electronic device of the technical solution of the present invention comprises a housing, two piezoelectric actuators arranged in the housing, wherein one piezoelectric actuator is close to the screen side and installed in the first fixed cavity. During the call, it can receive an excitation signal and then emit a first sound wave, which is received by the user by driving the screen to vibrate. At the same time, the other piezoelectric actuator receives a specific excitation during the call, so that it emits a second sound wave with an opposite phase to the first sound wave, and drives the rear shell to vibrate and transmit. In this way, at a relatively far position from the electronic device, the distance difference between the two piezoelectric actuators and the electronic device can be ignored, so that an acoustic dipole effect can be formed, that is, the second sound wave will reduce the propagation of the first sound wave, and then achieve the function of reducing the sound leakage during the call. For the user of the electronic device, since the distance difference between the two piezoelectric actuators and the user's ear does not meet the conditions of the acoustic dipole effect, it will not affect the user's reception of call information. In addition, the piezoelectric actuator can be made thinner in thickness relative to other sound-emitting components, so it will not occupy too much space in the housing while achieving a better sound leakage prevention effect, which is conducive to thinness. Moreover, the piezoelectric actuator drives the screen or back cover to vibrate through its own deformation, without the need to open holes in the shell, which can improve the waterproof performance of the electronic device and the integrity of the logo. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 A partial cross-sectional view of an electronic device according to an embodiment of the present invention.

[0023] Description of Figure Numbers:

[0024] Label name Label name 100 Electronic devices 13 Back shell 10 case 15 Shell 10a First fixed cavity 151 First fixing slot 10b Second fixing cavity 153 Second fixing slot 11 Screen 30 Piezoelectric Actuator

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The present invention provides an electronic device 100 .

[0030] Please refer to Figure 1In one embodiment of the present invention, the electronic device 100 includes a shell 10 and two piezoelectric actuators 30, the shell 10 includes a screen 11, a rear shell 13 and a middle shell 15 connecting the screen 11 and the rear shell 13, the screen 11 and the middle shell 15 enclose a first closed fixed cavity 10a, and the rear shell 13 and the middle shell 15 enclose a second closed fixed cavity 10b; the two piezoelectric actuators 30 are respectively installed in the first fixed cavity 10a and the second fixed cavity 10b, one of the piezoelectric actuators 30 receives excitation to drive the screen 11 to vibrate and emit a first sound wave; the other piezoelectric actuator 30 receives excitation to drive the rear shell 13 to vibrate and emit a second sound wave, and the first sound wave and the second sound wave have opposite phases.

[0031] In this embodiment, the electronic device 100 can be a mobile terminal, such as a mobile phone, a tablet computer, a laptop computer, or a wearable device, such as a smart watch, a VR device, etc., or other devices that are controlled by circuits and can make sounds, which are not limited here.

[0032] Specifically, the electronic device 100 includes a housing 10 and two piezoelectric actuators 30. The material of the housing 10 can be plastic or metal, which is not limited here. It can be set according to actual needs, and can provide a good installation foundation and protection foundation for each component, and can also take into account the aesthetic effect. Of course, the overall shape of the housing 10 can also be set according to the actual product type, such as a cuboid, a cube, a cylinder, etc., which is not limited here. Specifically, taking the electronic device 100 as a mobile phone as an example, the housing 10 includes a screen 11, a rear shell 13 and a middle shell 15 connecting the two, and the middle shell 15 and the screen 11 and the rear shell 13 are all detachable connection methods, such as snaps, threads, etc., which facilitates the assembly of various components into the interior of the housing 10 and facilitates the maintenance or replacement of components when necessary. Of course, the connection method of the middle shell 15 with the screen 11 and the rear shell 13 can also be bonding to improve the connection sealing. In addition, the rear shell 13 and the middle shell 15 can also be an integrated structure to improve the structural strength of the housing 10.

[0033] The screen 11 and the middle shell 15 are enclosed to form a first fixed cavity 10a, and the rear shell 13 and the middle shell 15 are enclosed to form a second fixed cavity 10b, which are respectively used to install two piezoelectric actuators 30, so that the two are close to the screen 11 and the rear shell 13 respectively. Of course, the electronic device 100 also includes a control component, which includes a controller and a circuit. The shell 10 is also formed with other cavities for installing the controller and the circuit. When the piezoelectric actuator 30 is installed in the shell 10, both are electrically connected to the controller through the circuit, so that the controller provides and sends corresponding excitation signals to both. The controller can be the main control board of the electronic device 100, or it can be a separately arranged control structure, which is electrically connected to the main control board of the electronic device 100, which is not limited here. In addition, the shell 10 can also be used to assemble components that realize other functions of the electronic device 100, such as a display component, a sensor or a power supply, etc., which will not be repeated here.

[0034] Among them, the piezoelectric actuator 30 generally includes piezoelectric ceramics, and the sound-generating principle utilizes the piezoelectric effect of piezoelectric ceramics and the principle of conversion of electrical energy to mechanical energy. After the audio excitation signal is passed into the piezoelectric ceramics, it can generate expansion and contraction vibrations, thereby driving the surrounding air and the housing 10 to vibrate. The structures and shapes of the two piezoelectric actuators 30 can be the same. For example, both piezoelectric actuators 30 are thin-sheet structures. The piezoelectric actuator 30 close to the screen 11 receives the excitation signal of the controller, and the excitation signal is the voice signal that the electronic device 100 needs to transmit. After receiving the excitation signal, the piezoelectric actuator 30 can drive the screen 11 to vibrate and generate sound, which is converted into the first sound wave and received by the user. This sound generation mode is surface sound generation, which can improve the sound loudness and sound quality of the electronic device 100 and meet the use requirements. After receiving the excitation signal, the piezoelectric actuator 30 near the rear shell 13 can drive the rear shell 13 to vibrate, generating a second sound wave with a phase opposite to the first sound wave, so that the first sound wave near the screen 11 cannot be received at a position beyond a certain distance due to the acoustic dipole effect. Here, the two piezoelectric actuators 30 are fixed in the first fixed cavity 10a and the second fixed cavity 10b. The sizes of the first fixed cavity 10a and the second fixed cavity 10b do not need to be large, and can be adapted to the sizes of the two piezoelectric actuators 30 so that they can drive the shell 10 to vibrate. The first fixed cavity 10a and the second fixed cavity 10b are arranged at intervals to reduce the vibration effect between the two piezoelectric actuators 30. The cross-sectional shape of the piezoelectric actuator 30 can be a rectangular parallelepiped, a cube or a disc, which is not limited here.

[0035] Here, the overall shape of the shell 10 is a rectangular parallelepiped, and the screen 11, the middle shell 15 and the rear shell 13 are connected in sequence in the thickness direction. Therefore, the two piezoelectric actuators 30 are arranged in a direction perpendicular to the screen 11, that is, arranged in the thickness direction, so that the thin film structure of the piezoelectric actuator 30 can be effectively utilized, and the space occupied in the surface direction of the shell 10 is effectively reduced, and the thickness of the shell 10 will not be increased, which is conducive to thinning. At the same time, the distance between the two piezoelectric actuators 30 can also be further reduced, which can further increase the acoustic dipole effect at a long distance, and is more conducive to preventing the leakage of call information. Here, a piezoelectric actuator 30 drives the screen 11 to vibrate and make a sound, and the vibration effect of the piezoelectric actuator 30 on the rear shell 13 can be ignored. At the same time, another piezoelectric actuator 30 drives the rear shell 13 to vibrate and make a sound, and the piezoelectric actuator 30 is also ignored.

[0036] The electronic device 100 of the technical solution of the present invention includes a housing 10 and two piezoelectric actuators 30 arranged in the housing 10, wherein one piezoelectric actuator 30 is close to the screen 11 side and is installed in the first fixed cavity 10a. During a call, it can receive an excitation signal and then emit a first sound wave, which is received by the user by driving the screen 11 to vibrate. At the same time, the other piezoelectric actuator 30 simultaneously receives a specific excitation during a call, so that it emits a second sound wave with an opposite phase to the first sound wave, and drives the rear shell 13 to vibrate and transmit. In this way, at a relatively far position from the electronic device 100, the distance difference between the two piezoelectric actuators 30 and the electronic device 100 can be ignored, so that an acoustic dipole effect can be formed, that is, the second sound wave will reduce the propagation of the first sound wave, and then achieve the function of reducing the sound leakage during the call. For the user of the electronic device 100, since the distance difference between the two piezoelectric actuators 30 and the user's ear does not meet the conditions of the acoustic dipole effect, it will not affect the user's reception of call information. In addition, the piezoelectric actuator 30 can be made thinner than other sound-generating components, so it does not occupy too much space in the housing 10 while achieving a better sound leakage prevention effect, which is conducive to thinning. Moreover, the piezoelectric actuator 30 drives the screen 11 or the back cover 13 to vibrate through its own deformation, without opening a hole in the housing 10, which can improve the waterproof performance of the electronic device 100 and the integrity of the logo.

[0037] Please continue to refer to Figure 1 Optionally, the surface of the middle shell 15 facing the screen 11 is provided with a first fixing groove 151, and the screen 11 covers the first fixing groove 151 to enclose the first fixing cavity 10a; the surface of the middle shell 15 facing the rear shell 13 is provided with a second fixing groove 153, and the rear shell 13 covers the second fixing groove 153 to enclose the second fixing cavity 10b;

[0038] The two fixing parts of the two piezoelectric actuators 30 are fixed in the first fixing groove 151 and the second fixing groove 153 respectively, and the deformation parts of the two piezoelectric actuators 30 face the screen 11 and the rear cover 13 respectively.

[0039] In this embodiment, in order to achieve stable fixation of the two piezoelectric actuators 30, a first fixing groove 151 and a second fixing groove 153 are provided on two opposite surfaces of the middle shell 15. The openings of the first fixing groove 151 and the second fixing groove 153 are both rectangular. The screen 11 is buckled on one surface of the middle shell 15, thereby enclosing with the groove wall of the first fixing groove 151 to form a closed first fixing cavity 10a. The rear shell 13 is buckled on the other surface of the middle shell 15, thereby enclosing with the groove wall of the second fixing groove 153 to form a closed second fixing cavity 10b. Correspondingly, the piezoelectric actuator 30 is also a rectangular sheet, which has a fixing portion for fixed installation, and a deformation portion installed on the fixing portion, and the deformation portion can be a piezoelectric ceramic. Thereby, the fixing portion of the piezoelectric actuator 30 is connected to the bottom of the first fixing groove 151. The connection method here can be welding or bonding, etc., which is not limited here. Optionally, the piezoelectric actuator 30 is connected to the middle shell 15 by bonding, so that the assembly is more convenient and the cost is low, and the connection stability of the piezoelectric actuator 30 can be ensured. The deformation part used for telescopic deformation faces the screen 11 and the rear shell 13 respectively, so that the piezoelectric actuator 30 can realize the function of driving the screen 11 and the rear shell 13 to vibrate and sound on the basis of stable installation. And the piezoelectric actuator 30 can be easily disassembled and repaired through the detachable connection between the middle shell 15 and the screen 11, and the middle shell 15 and the rear shell 13, thereby improving convenience.

[0040] It is understandable that according to the habit of using the electronic device 100, the screen 11 will fit the user's ear. In this way, the deformation part of the piezoelectric actuator 30 drives the screen 11 to vibrate and make sound, which can be transmitted more directly to the user's ear, thereby increasing the sound area, improving the efficiency and accuracy of receiving call information, and increasing the volume of the user's received call information to ensure call quality.

[0041] Optionally, the deformation portion of one of the piezoelectric actuators 30 is spaced apart from the screen 11 , and the deformation portion of another of the piezoelectric actuators 30 is spaced apart from the rear housing 13 .

[0042] In this embodiment, the deformation part of the piezoelectric actuator 30 is set to be spaced apart from the screen 11 and the rear shell 13, that is, there is a part of the space in the first fixed cavity 10a that can provide the deformation space of the piezoelectric actuator 30 to ensure its sound performance and facilitate the assembly of the piezoelectric actuator 30. Of course, in other embodiments, the two deformation parts of the two piezoelectric actuators 30 can also abut the screen 11 and the rear shell 13 to form a stable installation structure, which can prevent the piezoelectric actuator 30 from loosening and instability, and enhance the vibration effect of driving the rear shell 13 and the screen 11.

[0043] Optionally, projections of the two piezoelectric actuators 30 on the middle shell 15 at least partially overlap.

[0044] In this embodiment, in order to further save space, the projections of the two piezoelectric actuators 30 on the surface of the middle shell 15 at least partially overlap, so as to enhance the strength of reducing the first sound wave at a long distance, further enhance the sound leakage prevention effect, and further reduce the space occupied in the lateral direction of the shell 10. Optionally, the two piezoelectric actuators 30 have the same shape and size, and the projections on the surface of the middle shell 15 overlap, further reducing the space occupied in the lateral direction of the shell 10, and further preventing the first sound wave on the side of the screen 11 from being leaked.

[0045] Optionally, the two piezoelectric actuators 30 are both disposed close to the upper end of the screen 11 .

[0046] It is understandable that according to the usage habits of mobile phones, when in use, the upper end of the mobile phone is usually placed close to the human ear. Therefore, the two piezoelectric actuators 30 are arranged close to the upper end of the screen 11 so that they can be closer to the human ear, which is more convenient for users to use and improve the call volume. Here, the top of the screen 11 is based on the normal placement state of the user when using the electronic device 100. The end of the screen 11 that is away from the human hand when the viewing habit is met, that is, when the electronic device 100 is in contact with the human ear, the end that is away from the ground in the vertical direction is the upper end.

[0047] Optionally, the two piezoelectric actuators 30 are both located in the middle of the screen 11 in the width direction.

[0048] In this embodiment, in order to further enhance the anti-leakage function, the two piezoelectric actuators 30 are arranged in the middle of the screen 11 in the width direction, that is, the projection of the piezoelectric actuator 30 close to the screen 11 on the screen 11 is the middle of the upper end of the screen 11, and the projection of the other piezoelectric actuator 30 on the screen 11 coincides with the projection of the piezoelectric actuator 30 on the screen 11, so that the piezoelectric actuator 30 close to the rear shell 13 can provide an equal offsetting function relative to the electronic device 100 in the width direction, ensuring that the leakage of call information can be avoided on both sides in the width direction of the electronic device 100, thereby further enhancing the uniformity of anti-leakage at various positions of the electronic device 100.

[0049] In addition, the electronic device 100 is provided with a piezoelectric actuator 30 at the upper end of the screen 11. When the electronic device 100 is playing sound externally, sound is also produced through this piezoelectric actuator 30. At this time, an excitation signal is also given to the piezoelectric actuator 30 close to the rear shell 13, so that it emits a sound wave with the same phase as the sound wave played externally by the piezoelectric actuator 30 close to the rear shell 13, thereby improving the external sound effect.

[0050] Of course, in other embodiments, the electronic device 100 also includes another sound-emitting component, which is arranged at the bottom of the shell 10, that is, the other end away from the two piezoelectric actuators 30, and is used for the sound external speaker function of the electronic device 100. At this time, the sound-emitting component at the bottom receives the excitation signal of the controller, and emits a fourth sound wave corresponding to the sound signal to be played externally. Then, the piezoelectric actuator 30 close to the rear shell 13 can receive another excitation signal, and emit a fifth sound wave with the same phase as the fourth sound wave, which can then improve the sound quality and volume of the electronic device 100 when playing externally, thereby improving the auditory experience.

[0051] The present invention further provides a sound control method for an electronic device 100 . The electronic device 100 is any one of the electronic devices 100 described above, which will not be described in detail herein.

[0052] The sound control method of the electronic device 100 comprises the following steps:

[0053] S1: Determine the working mode of the electronic device 100;

[0054] S2: when the electronic device 100 is in the handset mode, controlling the piezoelectric actuator 30 close to the screen 11 to receive stimulation and emit a first sound wave, and controlling another piezoelectric actuator 30 to emit a second sound wave with a phase opposite to that of the first sound wave;

[0055] S3: When the electronic device 100 is in the external speaker mode, the piezoelectric actuator 30 close to the screen 11 is controlled to receive stimulation and emit a first sound wave, and the other piezoelectric actuator 30 is controlled to emit a third sound wave with the same phase as the first sound wave.

[0056] It can be understood that the electronic device 100 has multiple working modes, for example, a lock screen mode when powered on, or an unlock mode, a web browsing mode or a call mode, and when the electronic device 100 is in a sound mode, it can be divided into a handset mode and a speaker mode. When the user uses the handset mode, he or she tends to receive more private information, which is not likely to be received by people around him or her. When the speaker mode is used, it means that the sound volume of the electronic device 100 tends to be increased.

[0057] In this embodiment, by adding a piezoelectric actuator 30 to the electronic device 100, that is, setting two piezoelectric actuators 30, the two are coordinated to achieve a better user experience. Therefore, when controlling the sound of the piezoelectric actuator 30 close to the rear shell 13, in step S1, the working mode of the electronic device 100 must be determined first. The determination method here can detect the working mode of the electronic device 100 through a sensor. When a certain function is triggered by a user operation, it can be detected by the sensor and sent to the controller. For example, when the user triggers the call mode, the electronic device 100 will automatically jump to the handset mode. Or, the triggering condition of the external speaker module is detected. When it is detected that the external speaker module is triggered, it can be determined as the external speaker mode. When it is not triggered, it is basically determined as the handset mode. Or, when the sensor detects that the user fits the electronic device 100 to the human ear, it can be determined as the handset mode; or, the sensor can also detect whether accessories such as headphones are connected or not, so as to determine whether the electronic device 100 is in the handset mode.

[0058] In step S2, when the earpiece mode is determined, an excitation signal can be given to the piezoelectric actuator 30 close to the rear shell 13, causing it to convert and emit a second sound wave with an opposite phase to the piezoelectric actuator 30 on the screen 11 side, forming an acoustic dipole effect at a long distance around the user to achieve the effect of preventing sound leakage.

[0059] In step S3, when the user triggers the external speaker button or triggers the music playback without detecting the connection of the earphone, it can be determined that the electronic device 100 is in the external speaker mode. At this time, it is necessary to give another excitation signal to the piezoelectric actuator 30 close to the rear shell 13, so that it emits a third sound wave with the same phase as the piezoelectric actuator 30 on the screen 11 side, driving the rear shell 13 to achieve surface sound, thereby improving the sound loudness and sound quality of the electronic device 100 to meet usage requirements.

[0060] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An electronic device, characterized in that: The electronic device comprises: A housing, the housing comprising a screen, a rear housing, and a middle housing connecting the screen and the rear housing, the screen and the middle housing forming a sealed first fixed cavity, and the rear housing and the middle housing forming a sealed second fixed cavity; and Two piezoelectric actuators, the two piezoelectric actuators are respectively installed in the first fixed cavity and the second fixed cavity, one of the piezoelectric actuators receives excitation to drive the screen to vibrate and emit a first sound wave; the other piezoelectric actuator receives excitation to drive the rear shell to vibrate and emit a second sound wave, and the first sound wave and the second sound wave have opposite phases; The surface of the middle shell facing the screen is provided with a first fixing groove, and the screen covers the first fixing groove to enclose the first fixing cavity; the surface of the middle shell facing the rear shell is provided with a second fixing groove, and the rear shell covers the second fixing groove to enclose the second fixing cavity; The two fixed parts of the two piezoelectric actuators are respectively fixed in the first fixed groove and the second fixed groove, the two deformable parts of the two piezoelectric actuators are respectively facing the screen and the rear shell, and the two deformable parts of the two piezoelectric actuators abut against the screen and the rear shell; When the electronic device is playing sound externally, the piezoelectric actuator close to the screen produces sound, and the piezoelectric actuator close to the rear shell is given an excitation signal to cause it to emit a sound wave with the same phase as the sound wave played externally by the piezoelectric actuator close to the screen.

2. The electronic device according to claim 1, wherein: The piezoelectric actuator is connected to the middle shell by bonding.

3. The electronic device according to any one of claims 1 to 2, characterized in that: The projections of the two piezoelectric actuators on the middle shell at least partially overlap.

4. The electronic device according to claim 3, characterized in that: The two piezoelectric actuators are both arranged close to the upper end of the screen.

5. The electronic device according to claim 3, characterized in that: The two piezoelectric actuators are both located in the middle of the screen in the width direction.

6. The electronic device according to any one of claims 1 to 2, characterized in that: The electronic device further comprises a controller, which is arranged in the housing and electrically connected to both of the piezoelectric actuators to send an excitation signal.

7. The electronic device according to claim 1, wherein: The electronic device is a mobile phone.

8. A sound control method for an electronic device as claimed in any one of claims 1 to 7, characterized in that: The sound control method of the electronic device comprises the steps of: determining an operating mode of the electronic device; When the electronic device is in the handset mode, the piezoelectric actuator close to the screen is controlled to receive stimulation and emit a first sound wave, and the other piezoelectric actuator is controlled to emit a second sound wave with a phase opposite to the first sound wave; When the electronic device is in a speaker mode, the piezoelectric actuator close to the screen is controlled to receive stimulation and emit a first sound wave, and the other piezoelectric actuator is controlled to emit a third sound wave with the same phase as the first sound wave.

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