CN210202072U

CN210202072U - Electroacoustic conversion device and electronic equipment using same

Info

Publication number: CN210202072U
Application number: CN201921426376.3U
Authority: CN
Inventors: Shoujing Zhu; 朱守经; Tao Zhang; 张韬; Xin Yan; 闫鑫
Original assignee: Jingtuo Liyin Technology (beijing) Co Ltd; Beijing Xiaomi Mobile Software Co Ltd
Current assignee: Jingtuo Liyin Technology (beijing) Co Ltd; Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2020-03-27
Anticipated expiration: 2029-08-29

Abstract

The electroacoustic conversion device comprises a frame, a substrate, piezoelectric elements, a balancing weight and a driven plate, wherein more than two piezoelectric elements are symmetrically arranged at two ends of one plane or two planes of the substrate, so that the balancing weight connected to the substrate and the driven plate connected with the balancing weight are driven in a balanced manner, and a sound production structure connected with the driven plate can be driven to produce sound through vibration. The utility model discloses electroacoustic conversion device simple structure, sensitivity are high, calorific capacity is low, thickness is little, have better tone quality, are suitable for wide application in various sound production equipment.

Description

Electroacoustic conversion device and electronic equipment using same

Technical Field

The utility model relates to an electroacoustic conversion technology field, concretely relates to electroacoustic conversion device and use its electronic equipment.

Background

With the development of electronic communication technology, the use of electronic devices is becoming more and more popular, the user experience requirements on electronic devices are also becoming higher and higher, and various electronic devices are required to have smaller thickness and volume.

The sound production technology of electronic equipment in the current market is mainly an electromagnetic driving mode with a voice coil and a magnetic circuit system and a piezoelectric driving mode utilizing the inverse piezoelectric effect. The electro-acoustic conversion device adopting the electromagnetic driving mode has a complex structure, large thickness and large heat productivity. The piezoelectric driving type electroacoustic conversion device has the advantages of small thickness, light weight and the like, so the piezoelectric driving type electroacoustic conversion device is widely applied to sound output of small equipment, however, the conventional piezoelectric sound generation device mostly adopts a single piezoelectric element, the sensitivity is low, the total harmonic distortion is large, the sound quality of the piezoelectric sound generation device cannot meet the requirements of users, and structural improvement is needed.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the utility model is to provide an electroacoustic conversion device and use its electronic equipment that thickness is little, the drive is stable, simple structure to solve current piezoelectricity sound production component sensitivity and lower, the not good enough shortcoming of tone quality.

The embodiment of the utility model provides an electroacoustic conversion device, include:

a frame;

the material of the substrate is configured to enable the electroacoustic conversion device to obtain the expected frequency response curve characteristic;

at least two piezoelectric elements connected with the substrate and configured to controllably drive the substrate to vibrate relative to the frame;

a driven plate; and

the balancing weight is connected with the substrate and the driven plate;

wherein the region where the substrate is connected to the piezoelectric element does not overlap the region where the weight and the substrate are connected.

Preferably, both ends of the substrate are fixedly connected with the frame, and the whole piezoelectric element is arranged on the substrate.

Preferably, the piezoelectric element is fixedly connected between an end of the substrate and the frame.

Preferably, the substrate comprises a first surface and a second surface opposite to each other, and the piezoelectric element is fixedly connected to the first surface and/or the second surface.

Preferably, the weight block is fixedly connected to the middle of the first surface and/or the second surface.

Preferably, the piezoelectric elements are two and symmetrically arranged at two ends of the first surface or the second surface.

Preferably, the frame comprises:

a frame;

a mounting region configured to be connected with the substrate or the piezoelectric element; and

an accommodating groove configured to accommodate the substrate and/or the piezoelectric element, a depth of the accommodating groove being configured to allow the substrate and/or the piezoelectric element to vibrate therein.

Preferably, the length of the mounting region is configured to be a predetermined length so that a desired frequency response curve characteristic is obtained in the deformation region of the substrate.

Preferably, the area of the driven plate is larger than the sectional area of the balancing weight.

The embodiment of the utility model also provides an electronic device, which comprises a screen and any one of the electroacoustic conversion devices provided by the embodiment of the utility model;

wherein, the driven plate is fixedly connected with the screen.

The utility model discloses electroacoustic conversion device includes frame, base plate, piezoelectric element, balancing weight and driven plate, through setting up a plane or two planar both ends at the base plate with piezoelectric element more than two symmetrically, realizes the balanced drive to the balancing weight of connecting on the base plate and the driven plate of being connected with the balancing weight to can drive the sound production structure vibration sound production of being connected with the driven plate. The utility model discloses electroacoustic conversion device simple structure, sensitivity are high, calorific capacity is low, thickness is little, have better tone quality, are suitable for wide application in various sound production equipment.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 is a schematic structural view of an electroacoustic transducer according to a first embodiment of the present invention;

fig. 2 is an exploded view of the structure of an electroacoustic transducer device according to a first embodiment of the present invention;

fig. 3 is a sectional view a-a of an electroacoustic transducer device according to a first embodiment of the present invention;

fig. 4 is a schematic structural view of a frame of an electroacoustic transducer device according to a second embodiment of the present invention;

fig. 5 is a cross-sectional view of an electroacoustic transducer device according to a third embodiment of the present invention;

fig. 6 is a cross-sectional view of an electroacoustic transducer device according to a fourth embodiment of the present invention;

fig. 7 is an exploded view of an electronic device according to a fifth embodiment of the present invention;

fig. 8 is a cross-sectional view of an electronic device according to a fifth embodiment of the present invention.

Description of reference numerals:

1-a frame; 11-a frame; 12-a mounting area; 13-accommodating grooves; 2-a substrate; 3-a piezoelectric element; 4-a balancing weight; 5-driven plate; 6-screen; 7-middle frame; 8-rear cover.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in detail. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. Well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

Unless the context clearly requires otherwise, throughout this specification, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, what is meant is "including, but not limited to".

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are intended to be inclusive and mean that, for example, they may be fixedly connected or detachably connected or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

When an element or layer is referred to as being "on," "engaged to," "connected to" or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Spatially relative terms, such as "inner," "outer," "below," "lower," "above," "upper," and the like, are used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The first embodiment is as follows:

fig. 1 is a schematic structural view of an electroacoustic conversion device of the present embodiment, and fig. 2 is an exploded structural view of the electroacoustic conversion device of the present embodiment. As shown in fig. 1 to 2, the electroacoustic conversion device includes a frame 1, a base plate 2, a piezoelectric element 3, a driven plate 5, and a weight 4. 2 fixed mounting of base plate on frame 1, base plate 2 have relative first surface and second surface, the first surface is base plate 2 towards one side surface from piece 5, and piezoelectric element 3 fixed connection is on the first surface of base plate 2, leaves the blank region between two piezoelectric element 3 in 2 first surface middle parts of base plate, and from piece 5 and one side of balancing weight 4 to be connected, the opposite side of balancing weight 4 is connected in base plate 2 the blank region.

The connection among all components in the electroacoustic conversion device can adopt fixed connection modes such as bonding, riveting, welding, bolt connection and the like. Preferably, this embodiment uses an adhesive means, i.e. the components are firmly connected together by the adhesive force of the adhesive on the surfaces of the components. Because each component of the electroacoustic conversion device is small in thickness, compared with mechanical connection modes such as riveting and bolt connection, the stress distribution of the connection part can be more uniform by adopting a bonding mode, the damage of the components is prevented, the cost can be reduced, and the weight of the electroacoustic conversion device can be reduced.

Fig. 3 is a sectional view a-a of the electroacoustic conversion device of the present embodiment, and fig. 3 is a schematic structural view of the electroacoustic conversion device in fig. 1 taken along the direction a-a. As shown in fig. 2-3, the frame 1 includes a frame 11, a mounting area 12 and a receiving groove 13, and the widths of the mounting area 12 and the receiving groove 13 are matched with the width of the substrate 2, so as not to affect the normal operation of the substrate 2. Both ends of the second surface of the substrate 2 are bonded to the mounting regions 12, and the middle portion of the substrate 2 can vibrate within the receiving groove 13. The substrate 2 may be a sheet material with good toughness, such as a steel sheet or a plastic sheet, and a person skilled in the art may select parameters such as a material and a size of the substrate 2 according to a desired frequency response curve characteristic. Preferably, the thickness of the mounting region 12 is smaller than that of the bezel 11, and the height of the non-adhesive surface side of the piezoelectric element 3 is substantially flush with the frame 1 in an initial state (a state where no external force is applied to the electroacoustic conversion device and no electricity is applied to the piezoelectric element 3) after the electroacoustic conversion device is mounted, so that the thickness of the electroacoustic conversion device can be reduced and the substrate 2 can be prevented from being relatively displaced. The receiving groove 13 may be a through hole or a blind hole having a bottom surface lower than the mounting region 12. If the mounting groove is a blind hole, its depth should be such that the base plate 2 does not contact said blind hole within a predetermined operating vibration range. Preferably, the housing groove 13 is a through hole, and the thickness of the electroacoustic conversion device can be further reduced.

The piezoelectric element is an element that converts electrical energy and mechanical energy by using the inverse piezoelectric effect. The inverse piezoelectric effect refers to a phenomenon that an alternating electric field is applied to a crystal to cause mechanical deformation of the crystal. The piezoelectric element is connected with the vibrating diaphragm and the like, so that the piezoelectric element drives the vibrating diaphragm and the like to vibrate, and further pushes air to vibrate, sound pressure is generated, and sound is produced. The piezoelectric element applied to the sounding device mainly comprises piezoelectric ceramics, piezoelectric polymers and composite piezoelectric materials, and a person skilled in the art can select specific types of piezoelectric elements according to needs.

As shown in fig. 1 to 3, in the present embodiment, two piezoelectric elements 3 are provided, the two piezoelectric elements 3 are symmetrically adhered to the first surface of the substrate 2, and the entirety of the piezoelectric elements 3 is provided on the first surface of the substrate 2. Two piezoelectric element 3 symmetries set up, can realize balanced, the stable drive of electroacoustic conversion device, can effectively reduce total harmonic distortion to promote tone quality, a plurality of piezoelectric element 3 compare 3 drive power of single piezoelectric element stronger moreover, and sensitivity is higher. It will be appreciated that more than two piezoelectric elements 3 may be provided, for example three or four. Preferably, the piezoelectric element 3 is not in contact with the frame 1 when mounted, so as to prevent the piezoelectric element 3 from interfering with the frame 1 and affecting the normal operation of the electroacoustic transducer device.

The weight 4 is bonded to a blank area between the two piezoelectric elements 3 on the center of the first surface of the substrate 2. Since the bending deformation of the substrate 2 is very small, the weight 4 is provided to amplify the deformation of the substrate 2, thereby increasing the amplitude of the electroacoustic transducer and adjusting the frequency response curve characteristic of the electroacoustic transducer. The counterweight 4 can be made of copper, iron and other materials with higher density so as to reduce the volume of the electroacoustic conversion device. Preferably, the height of the weight 4 after installation is greater than the height of the piezoelectric element 2 and the frame 11 of the frame 1, so as to prevent the driven plate 5 connected with the weight 4 from contacting the piezoelectric element 2 or the frame 11 to affect the normal operation of the electroacoustic conversion device. The specific size and weight of the weight 4 can be designed by those skilled in the art according to the frequency response curve characteristics desired to be obtained, and if necessary, the weight 4 can be additionally arranged in the center of the second surface of the substrate 2.

In another alternative embodiment, two piezoelectric elements 3 are symmetrically adhered to the second surface of the substrate 2, and the entirety of the piezoelectric elements 3 is disposed on the second surface of the substrate 2. The weight 4 is adhered to the center of the first surface of the substrate 2, and if necessary, the weight 4 may be disposed on the second surface of the substrate 2. The driven plate 5 is bonded to a weight 4 provided on the first surface.

One side of the driven plate 5 is adhered to the counterweight 4 on the first surface of the substrate 2, and the other side is used for being connected with components suitable for being driven by the electroacoustic conversion device to generate sound, such as a film, a screen of an electronic device and the like. The driven plate 5 does not contact the substrate 2, the piezoelectric element 3, or the frame 1. The driven plate 5 is of a sheet-like structure, and in the embodiment, the driven plate 5 is a steel plate which has better strength and toughness and can achieve smaller thickness. It is to be understood that the driven plate 5 may also be provided with other materials, for example, other metallic materials or high molecular polymer materials. The area of the driven plate 5 can be designed by those skilled in the art according to the frequency response characteristics desired to be obtained and the sensitivity of the driving of the electroacoustic conversion device. Generally, the driven plate 5 has a larger area than the cross-sectional area of the weight 4 to which it is bonded, so that the length of the electroacoustic transducer can be reduced while ensuring the sensitivity of the electroacoustic transducer, and the larger connection area prevents the sounding structure from being damaged due to excessive concentration of stress transmitted from the driven plate 5 when the sounding structure is connected to a sounding structure such as a film or a screen.

When the piezoelectric element 3 is powered on, due to the inverse piezoelectric effect, the piezoelectric element 3 generates a stretching or contracting phenomenon, the stretching or contracting of the piezoelectric element 3 drives the substrate 2 to generate bending deformation, so as to drive the counter weight block 4 and the driven plate 5 to vibrate up and down (the up-down direction corresponds to the up-down direction in fig. 3), and finally the driven plate 5 drives the sound production structure connected with the driven plate to produce sound through vibration.

Example two:

fig. 4 is a schematic structural view of a frame of the electroacoustic conversion device of the present embodiment. As shown in fig. 4, the frame 1 includes a bezel 11, a mounting area 12, and a receiving groove 13. In the present embodiment, the length of the mounting region 12 is longer, that is, the bonding area between the substrate 2 and the mounting region 12 is larger, so that the bending deformation region of the substrate 2 is reduced, the amplitude of the electroacoustic conversion device is reduced, and the frequency response curve characteristic of the electroacoustic conversion device is changed.

The structure, size, connection relationship and connection manner of the substrate 2, the piezoelectric element 3, the weight 4, the driven plate 5, the frame 11 of the frame 1 and the accommodating groove 13 are the same as those of the first embodiment, and are not described herein again.

Example three:

fig. 5 is a sectional view of the electroacoustic conversion device of the present embodiment, the sectional direction of which is referred to the a-a direction of fig. 1. As shown in fig. 5, in the present embodiment, both ends of the substrate 2 are not connected to the mounting regions 12, but one ends of the two piezoelectric elements 3 are bonded to the mounting region 12 at one end of the frame 1, the other ends of the piezoelectric elements 3 are bonded to the substrate 2, and the substrate 2 is not in contact with the frame 1. In the present embodiment, the length of the substrate 2 is short, and the bending deformation region of the substrate 2 is small, so that the frequency response curve characteristic of the electroacoustic conversion device can be changed by changing the size of the substrate 2 without changing other members. Meanwhile, the piezoelectric element 3 is directly bonded to the mounting region 12, so that the substrate 2 is completely located in the accommodation groove 13, and the thickness of the entire electroacoustic transducer device can be reduced.

The structure, size, and connection method of the substrate 2, the piezoelectric element 3, the weight 4, the driven plate 5, and the frame 1 in this embodiment are the same as those in the first to second embodiments, and are not described again.

Example four:

fig. 6 is a sectional view of the electroacoustic conversion device of the present embodiment, the sectional direction of which is referred to the direction a-a of fig. 1. As shown in fig. 6, in the present embodiment, four piezoelectric elements 3 are included, and the first plane and the second plane of the substrate 2 are each provided symmetrically with two piezoelectric elements 3. Compared with the first embodiment to the third embodiment, the electroacoustic conversion device of the present embodiment has a larger driving force and higher sensitivity.

The structure, size, and connection method of the substrate 2, the piezoelectric element 3, the weight 4, the driven plate 5, and the frame 1 in this embodiment are the same as those in the first to third embodiments, and are not described again here.

Example five:

the electroacoustic conversion device according to the first to fourth embodiments may be applied to various electronic devices having a sound production or vibration function, such as a smart phone, a tablet pc, a handheld game machine, a sound box, and the like. The present embodiment provides an electronic device having the electroacoustic conversion device of any one of embodiments one to four. The following description will be given taking an example in which the electroacoustic conversion device is applied to a mobile phone.

Fig. 7 is an exploded view of the electronic device of the present embodiment, fig. 8 is a cross-sectional view of the electronic device of the present embodiment, and the cross-sectional direction of fig. 8 can refer to the direction a-a of fig. 1. As shown in fig. 7-8, the mobile phone includes an electroacoustic transducer and a screen 6, the structure of the electroacoustic transducer is the same as that of the electroacoustic transducer in the first embodiment, and the electroacoustic transducer includes a frame 1, a substrate 2, two piezoelectric elements 3, a weight 4 and a driven plate 5, where the two piezoelectric elements 3 are completely disposed on the first surface of the substrate 2, and of course, those skilled in the art can also adopt the electroacoustic transducer of the other embodiments of the present invention. The mobile phone also comprises a middle frame 7 and a rear cover 8, wherein the rear cover 8 can be made of high polymer materials (such as polycarbonate, Kevlar fiber, glass fiber and the like), metal materials (such as aluminum alloy, stainless steel and the like) or inorganic non-metal materials (such as ceramic and the like). Since some inorganic non-metallic materials such as ceramics are fragile and cannot serve as a supporting structural member, the middle frame 7 may be made of a high polymer material or a metal material, and preferably, a metal material with high strength such as an aluminum alloy or a titanium alloy may be used. The back cover 8 is fixedly connected with one side of the middle frame 7, the screen 6 is fixedly connected with the other side of the middle frame 7, and the electroacoustic conversion device is arranged in a cavity formed by the back cover 8, the middle frame 7 and the screen 6. Both ends of the frame 1 of the electroacoustic transducer are fixedly connected to the middle frame 7, and when the rear cover 8 is made of a material such as a metal or a high molecular polymer having a high strength, the frame 1 may be fixedly connected to the inner side (the side facing the screen 6) of the rear cover 8. Optionally, the inner side of the middle frame 7 has a boss, and the frame 1 is placed on the boss and fixedly connected with the middle frame, so that the electroacoustic conversion device is stably supported. The connection mode of the electroacoustic conversion device and the middle frame 7 or the back cover 8 can adopt bolt connection, welding, bonding and the like, and when the frame 1 is connected with the back cover 8, preferably, the connection mode of bonding is adopted, namely, the frame 1 is tightly connected with the back cover 8 through an adhesive, so that the area of the bonding surface is maximized and no gap exists, and the electroacoustic conversion device can be well fixed. The driven plate 5 of the electroacoustic conversion device is connected to the screen 6. Preferably, the driven plate 5 is connected to the screen 6 by bonding so that the connection surface is sufficiently contacted, and the vibration of the electroacoustic transducer device can be transmitted to the screen 6 to the maximum extent, thereby improving the sound effect.

In another alternative embodiment, the frame 1 of the electroacoustic transducer device is connected with the middle frame 7 of the mobile phone, and the driven plate 5 is connected with the rear cover 8, i.e. the electroacoustic transducer device can drive the rear cover 8 to vibrate and produce sound.

In this embodiment, the cell-phone still includes power and treater, piezoelectric element 3's electrode with the power is connected, the power receives corresponding electric field is applyed to piezoelectric element 3 to the control of treater, makes piezoelectric element 3 warp, drives base plate 2, balancing weight 4 and driven plate 5 vibration, and then drives screen or back lid vibration sound production.

In this embodiment, the number and the arrangement position of the electroacoustic conversion devices may be designed by those skilled in the art as required, so as not to affect the arrangement of other components in the mobile phone. The electroacoustic conversion device can also be used as a vibration feedback element to drive the screen to vibrate and serve as a feedback signal for user operation.

The electronic equipment of this embodiment has used corresponding electroacoustic conversion device, and is thinner, weight is lighter for the sound generating component thickness that adopts the electromagnetic drive mode, can make electronic equipment realize frivolousization, and is better for traditional piezoelectricity sound production structure tone quality to can promote user's use and experience. And simultaneously, use the utility model discloses an behind the electroacoustic transducer that the embodiment corresponds, components such as electronic equipment's screen or shell directly need not to set up the sound hole in addition as the sound source, are favorable to realizing electronic equipment's waterproof dustproof to can improve electronic equipment's screen and account for than.

It should be understood by those skilled in the art that the mobile phone is only one example of the electronic device of the present embodiment, and the electronic device may also be an earphone, a sound box, or the like, and accordingly, the driven plate is connected with the sound-generating structure such as a vibrating diaphragm, and drives the sound-generating structure such as the vibrating diaphragm to generate sound by vibration.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. An electro-acoustic conversion device, comprising:

a frame (1);

a substrate (2);

at least two piezoelectric elements (3) connected to the substrate (2) and configured to controllably drive the substrate (2) into vibration relative to the frame (1);

a driven plate (5); and

a counter weight (4) connecting the substrate (2) and the driven plate (5);

wherein the area where the substrate (2) is connected with the piezoelectric element (3) does not overlap with the area where the weight (4) is connected with the substrate (2).

2. The electroacoustic conversion device of claim 1, wherein both ends of the base plate (2) are fixedly connected to the frame (1), and the entirety of the piezoelectric element (3) is provided on the base plate (2).

3. The electroacoustic conversion device of claim 1, characterized in that the piezoelectric element (3) is fixedly connected between the end of the substrate (2) and the frame (1).

4. Electro-acoustic conversion device according to claim 1, characterised in that the substrate (2) comprises a first and a second opposite surface, the piezoelectric element (3) being fixedly connected to the first and/or the second surface.

5. Electro-acoustic transducer device as claimed in claim 4, characterised in that the weight (4) is fixedly connected to the middle of the first surface and/or the second surface.

6. The electroacoustic conversion device of claim 5, wherein the piezoelectric elements (3) are two, symmetrically arranged at both ends of the first surface or the second surface.

7. The electroacoustic conversion device of claim 1, characterized in that the frame (1) comprises:

a frame (11);

a mounting region (12) configured to be connected to the substrate (2) or the piezoelectric element (3); and

an accommodation groove (13) configured to accommodate the substrate (2) and/or the piezoelectric element (3), a depth of the accommodation groove (13) being configured to allow the substrate (2) and/or the piezoelectric element (3) to vibrate in the accommodation groove (13).

8. The electroacoustic conversion device of claim 7, characterized in that the length of the mounting area (12) is configured to a predetermined length such that a deformation area of the substrate (2) obtains a desired frequency response curve characteristic.

9. Electro-acoustic conversion device according to claim 1, characterised in that the driven plate (5) has an area larger than the cross-sectional area of the counterweight (4).

10. An electronic device, characterized by comprising a screen (6) and an electro-acoustic conversion device according to any one of claims 1-9;

wherein, the driven plate (5) is fixedly connected with the screen (6).