A sound generating device and a manufacturing method thereof, and a display device

Abstract

The present application provides a sound-generating device and a method for manufacturing the same, and a display device, and relates to the field of display technology. The sound-generating device includes: a substrate; a first electrode layer, a vibration layer, and a second electrode layer located on the substrate; wherein the vibration layer includes a first vibration sublayer and a second vibration sublayer, the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer, and at least part of the first electrode layer is in contact with the surface of the substrate close to the vibration layer, and the second electrode layer is located between the first vibration sublayer and the second vibration sublayer. The sound-generating device has a simple structure, a simple manufacturing process, and a low cost. The display device has a good sound effect and can realize screen sound.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a sound-generating device and a preparation method thereof, and a display device. Background Art

[0002] With the continuous development of speaker technology and display technology, people have higher and higher requirements for the sound effects of display products. At present, the speakers of display products are mostly installed on the side of the display products. When users play videos or audio, the sound usually comes out from one direction. The sound effects felt by users in different positions vary greatly, which reduces the user experience.

[0003] The present application proposes a new sound-emitting device, which can be arranged on the light-emitting surface of a display product, thereby achieving screen sound and improving user experience. Summary of the invention

[0004] The embodiments of the present application provide a sound-generating device and a preparation method thereof, and a display device. The sound-generating device has a simple structure, a simple manufacturing process, and a low cost. The display device has good sound effects and can realize screen sound.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] On the one hand, an embodiment of the present application provides a sound-generating device, comprising:

[0007] substrate;

[0008] A first electrode layer, a vibration layer, and a second electrode layer located on the substrate;

[0009] The vibration layer includes a first vibration sublayer and a second vibration sublayer, the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer and at least a portion of the first electrode layer is in contact with a surface of the substrate close to the vibration layer, and the second electrode layer is located between the first vibration sublayer and the second vibration sublayer.

[0010] In some embodiments of the present application, the sound-generating device further comprises a supporting layer and at least one cavity structure, and the supporting layer and the cavity structure are arranged in the same layer;

[0011] Among them, the supporting layer is located on a side of the first vibration sublayer away from the second vibration sublayer; the cavity structure is located between the first electrode layer and the first vibration sublayer, and an orthographic projection of the cavity structure on the substrate and an orthographic projection of the second electrode layer on the substrate have an overlapping area.

[0012] In some embodiments of the present application, the sound-generating device includes at least two of the cavity structures, and the second electrode layer includes a plurality of second sub-electrodes having the same number as the cavity structures;

[0013] Wherein, the second sub-electrodes are electrically connected to each other; and / or, the second sub-electrodes are disconnected from each other.

[0014] In some embodiments of the present application, the sound-generating device further includes a hollow area, and the hollow area and the second electrode layer are arranged in the same layer;

[0015] A partial area of ​​the first vibration sublayer and a partial area of ​​the second vibration sublayer are in contact with each other through the hollow area.

[0016] In some embodiments of the present application, the orthographic projection shape of the cavity structure on the substrate includes a combination of one or more of a circle, a square, a rectangle, and a hexagon.

[0017] In some embodiments of the present application, an orthographic projection shape of the cavity structure on the substrate is the same as an orthographic projection shape of the second sub-electrode on the substrate.

[0018] In some embodiments of the present application, the substrate and the support layer are an integrated structure;

[0019] Part of the first electrode layer contacts the surface of the substrate close to the cavity structure, and the remaining part of the first electrode layer contacts the surface of the support layer away from the substrate.

[0020] In some embodiments of the present application, the sound-generating device further comprises a bonding layer, wherein the bonding layer is located between the substrate and the supporting layer, and the substrate and the supporting layer are fixed by the bonding layer;

[0021] The first electrode layer covers the substrate, and a partial area of ​​the first electrode layer is located between the substrate and the supporting layer, and the remaining area of ​​the first electrode layer is located between the substrate and the cavity structure, and the bonding layer covers a portion of the first electrode layer located between the substrate and the supporting layer.

[0022] In some embodiments of the present application, materials of the substrate, the first electrode layer, the vibration layer and the second electrode layer are all light-transmitting materials.

[0023] On the other hand, an embodiment of the present application provides a method for preparing the sound-generating device as described above, the method comprising:

[0024] providing a substrate;

[0025] forming a first electrode layer;

[0026] forming a first vibrating sublayer;

[0027] forming a second electrode layer on the first vibration sublayer;

[0028] A second vibration sublayer is formed on the second electrode layer; the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer, and at least a portion of the first electrode layer contacts a surface of the substrate close to the vibration layer.

[0029] In yet another aspect, an embodiment of the present application provides a display device, comprising a display panel and at least one sound-generating device as described above;

[0030] The material of the sound-emitting device includes a light-transmitting material; at least a partial area of ​​the light-emitting side substrate of the display panel is configured to serve as the base of the sound-emitting device, and the first electrode layer is located on the light-emitting surface of the display panel.

[0031] In some embodiments of the present application, the size of the sound-generating device is the same as the size of the display panel, and the sound-generating device includes a cavity structure;

[0032] The display panel includes a display area and a frame area, the cavity structure of the sound-generating device has an orthographic projection on the display panel falling into the display area, and the supporting layer of the sound-generating device has an orthographic projection on the display panel falling into the frame area.

[0033] In some embodiments of the present application, the display device includes at least two of the sound-generating devices, and the display area of ​​the display panel includes a plurality of opening areas and non-opening areas other than the opening areas;

[0034] Wherein, when the sound-emitting device includes one of the cavity structures, the orthographic projection of the supporting layer of the sound-emitting device on the display panel falls into the non-opening area; when the sound-emitting device includes at least two of the cavity structures, the orthographic projection of the outer contour of the sound-emitting device on the display panel falls into the non-opening area.

[0035] In some embodiments of the present application, the sound-generating device includes at least two cavity structures;

[0036] The two cavity structures are configured to emit sound waves of different frequencies so that the display device can emit sound in a directionally controlled manner.

[0037] In some embodiments of the present application, the second electrode layer of the sound-generating device includes a plurality of second sub-electrodes having the same number as the cavity structures;

[0038] The second sub-electrodes are electrically connected to each other, and the orthographic projections of the two cavity structures on the substrate have different sizes.

[0039] In some embodiments of the present application, the second electrode layer of the sound-generating device includes a plurality of second sub-electrodes having the same number as the cavity structures;

[0040] The orthographic projections of the two cavity structures on the substrate have the same size, and the second sub-electrodes are disconnected from each other.

[0041] An embodiment of the present application provides a sound-emitting device and a preparation method thereof, and a display device, wherein the sound-emitting device includes: a substrate; a first electrode layer, a vibration layer, and a second electrode layer located on the substrate; wherein the vibration layer includes a first vibration sublayer and a second vibration sublayer, the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer, and at least a portion of the first electrode layer is in contact with a surface of the substrate close to the vibration layer, and the second electrode layer is located between the first vibration sublayer and the second vibration sublayer.

[0042] The sound-generating device provided by the embodiment of the present application has a simple structure, is easy to manufacture, has a low cost, and has a good sound-generating effect. In addition, since the second electrode layer is disposed between the first vibration sublayer and the second vibration sublayer, the second vibration sublayer protects the second electrode layer without affecting the vibration of the vibration layer, thereby reducing the risk of the second electrode layer falling off during the vibration of the vibration layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1-Figure 3 Schematic diagrams of four different structures of sound-generating devices provided in the embodiments of the present application;

[0045] Figure 4 A schematic diagram of the structure of a second electrode layer provided in an embodiment of the present application;

[0046] Figure 5 A curve relationship diagram of the thickness of the vibration layer and the radius of the cavity structure at different sound emission frequencies provided in an embodiment of the present application;

[0047] Figure 6 A flow chart of a method for preparing a sound-generating device provided in an embodiment of the present application;

[0048] Figure 7-10 The embodiments of the present application provide Figure 2a The intermediate structural diagram of the preparation process of the sound-generating device shown;

[0049] Figure 11-Figure 14 The embodiments of the present application provide Figure 3 The intermediate structural diagram of the preparation process of the sound-generating device shown;

[0050] Figure 15- Fig.18 Schematic diagram of the structures of five display devices provided in the embodiments of the present application. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In the drawings, the thickness of regions and layers may be exaggerated for clarity. The same reference numerals in the drawings represent the same or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0053] In the embodiments of the present application, unless otherwise specified, "plurality" means two or more; the orientation or positional relationship indicated by the term "on" and the like is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the structure or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0054] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0055] In the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with basically the same functions and effects. This is only for the purpose of clearly describing the technical solutions of the embodiments of the present application, and shall not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0056] In the related art, flat panel speakers mostly use a structure that combines a thin plate and an exciter. However, the sound frequency of such flat panel speakers is relatively high. In practical applications, they need to be used together with a bass speaker to obtain a better music playback effect. In addition, in the related art, PMUT (Piezoelectric Micromachined Ultrasonic Transducer) or CMUT (Capacitive Micromachined Ultrasonic Transducer) speakers prepared based on MEMS (Microfabrication Process) manufacturing technology are used to achieve better sound effects. However, the MEMS manufacturing process is complex and costly, and such speakers require multiple array-arranged speaker structures to achieve effective sound emission, making them difficult to use on a large scale.

[0057] Among them, the exciter is a harmonic generator that can modify and beautify the sound signal, and improve the sound quality, timbre, penetration and spatial sense of the sound by adding high-frequency harmonic components to the sound. MEMS manufacturing process is a general term for microstructure processing technology from nanometer scale to millimeter scale. It originated from semiconductor and microelectronics technology. It is a micro-processing technology that uses photolithography, epitaxy, thin film deposition, oxidation, diffusion, injection, sputtering, evaporation, etching, dicing and packaging as basic process steps to manufacture complex three-dimensional shapes.

[0058] Based on this, the embodiment of the present application provides a sound-generating device, referring to Figure 1 , Figure 2a or Figure 3 As shown, including:

[0059] Base 1;

[0060] A first electrode layer 2, a vibration layer 4 and a second electrode layer 5 located on a substrate 1;

[0061] Among them, the vibration layer 4 includes a first vibration sublayer 41 and a second vibration sublayer 42, the first electrode layer 2 is located on a side of the first vibration sublayer 41 away from the second vibration sublayer 42, and at least a portion of the first electrode layer 2 is in contact with the surface of the substrate 1 close to the vibration layer 4, and the second electrode layer 5 is located between the first vibration sublayer 41 and the second vibration sublayer 42.

[0062] In an exemplary embodiment, the material of the vibration layer 4 may include a combination of one or more of a polymer material, a fiber material, a metal material or a composite material. The material of the vibration layer 4 should have a relatively small density (to achieve lightness), a relatively large Young's modulus (to have a relatively good rigidity), and an appropriate damping factor (to absorb unnecessary noise emitted by the vibration layer 4 during vibration and reduce distortion).

[0063] Specifically, taking polymer materials as an example, the material of the vibration layer 4 may include a combination of one or more of polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polyetherimide (PEI), polyimide (PI), polyethylene naphthalate (PEN), polyetheretherketone (PEEK) and polypropylene (PP).

[0064] In an exemplary embodiment, the first vibration sublayer 41 and the second vibration sublayer 42 are made of the same material, so that the structure and the manufacturing process can be simplified and the cost can be reduced.

[0065] At least part of the first electrode layer 2 is in contact with the surface of the substrate 1 close to the vibration layer 4, and the first electrode layer 2 is a whole layer of thin film without patterning. Figure 3 As shown, a portion of the first electrode layer 2 is in contact with the surface of the substrate 1 close to the vibration layer 4; or, referring to Figure 2a As shown, all regions of the first electrode layer 2 are in contact with the surface of the substrate 1 close to the vibration layer 4 .

[0066] In the case where the first electrode layer 2 is conductive, the specific material of the first electrode layer 2 is not limited.

[0067] In an exemplary embodiment, since the second electrode layer 5 is located between the first vibration sublayer 41 and the second vibration sublayer 42, the second electrode layer 5 will vibrate along with the vibration of the vibration layer 4. Preferably, the material of the second electrode layer 5 can be set to a flexible conductive material, such as: a conductive material composed of nano silver wires, graphene or flexible carbon nanotube conductive materials, etc.

[0068] In an exemplary embodiment, since the second electrode layer 5 is located between the first vibration sublayer 41 and the second vibration sublayer 42, although the second electrode layer 5 will vibrate along with the vibration of the vibration layer 4, the first vibration sublayer 41 and the second vibration sublayer 42 on both sides of the second electrode layer 5 can protect the second electrode layer 5 and release the stress in the second electrode layer 5 to prevent it from falling off or cracking. Therefore, the material of the second electrode layer 5 is a common conductive material, such as copper (Cu), aluminum (Al) or ITO (Indium Tin Oxides, indium tin oxide), etc.

[0069] In an exemplary embodiment, the first electrode layer 2 and the second electrode layer 5 may be made of different conductive materials. For example, the material of the first electrode layer 2 is ITO, and the material of the second electrode layer 5 is graphene.

[0070] In the embodiment of the present application, voltages are applied to the first electrode layer 2 and the second electrode layer 5 respectively, so that the vibration layer 4 vibrates under the action of the electric field and converts the electric signal into an acoustic signal. As the voltages applied to the first electrode layer 2 and the second electrode layer 5 change, the vibration frequency of the vibration layer 4 changes. The magnitudes of the voltages applied to the first electrode layer 2 and the second electrode layer 5 are not limited here and can be determined according to actual conditions.

[0071] In an exemplary embodiment, the material of the substrate 1 may include a rigid material or a flexible material. For example, the rigid material may include glass, and the flexible material may include a flexible light-transmitting resin.

[0072] The size of the sound-generating device provided in the embodiment of the present application is not limited here. For example, the size of the sound-generating device may range from 2 mm to 800 mm, which may be adjusted according to actual needs.

[0073] An embodiment of the present application provides a sound-emitting device, which includes: a substrate 1; a first electrode layer 2, a vibration layer 4, and a second electrode layer 5 located on the substrate 1; wherein the vibration layer 4 includes a first vibration sublayer 41 and a second vibration sublayer 42, the first electrode layer 2 is located on a side of the first vibration sublayer 41 away from the second vibration sublayer 42, and at least a portion of the first electrode layer 2 is in contact with a surface of the substrate 1 close to the vibration layer 4, and the second electrode layer 5 is located between the first vibration sublayer 41 and the second vibration sublayer 42.

[0074] The sound-generating device provided by the embodiment of the present application has a simple structure, is easy to manufacture, has a low cost, and has a good sound-generating effect. In addition, since the second electrode layer 5 is disposed between the first vibration sublayer 41 and the second vibration sublayer 42, the second vibration sublayer 42 protects the second electrode layer 5 without affecting the vibration of the vibration layer 4, thereby reducing the risk of the second electrode layer 5 falling off during the vibration of the vibration layer 4.

[0075] In some embodiments of the present application, reference Figure 1 , Figure 2a or Figure 3 As shown, the sound-generating device further includes a supporting layer 3 and at least one cavity structure 6, and the supporting layer 3 and the cavity structure 6 are arranged in the same layer;

[0076] Among them, the supporting layer 3 is located on the side of the first vibration sublayer 41 away from the second vibration sublayer 42; the cavity structure 6 is located between the first electrode layer 2 and the first vibration sublayer 41, and the orthographic projection of the cavity structure 6 on the substrate 1 and the orthographic projection of the second electrode layer 5 on the substrate 1 have an overlapping area.

[0077] It should be noted that Figure 1 These are two parts of a sound-generating device. To make it easier to see the specific structures of the cavity structure 6 and the supporting layer 3, the sound-generating device is divided into two parts for drawing.

[0078] In practical applications, the support layer 3 and the cavity structure 6 are formed simultaneously by patterning the support film. The depth of the cavity structure 6 along the direction perpendicular to the substrate 1 is the same as the thickness of the support layer 3 along the direction perpendicular to the substrate 1 .

[0079] In the exemplary embodiment, the cavity structure 6 is provided to provide a suitable vibration space for the vibration layer 4. In practical applications, the vibration area of ​​the vibration layer 4 is related to the size of the cavity structure 6, and the vibration frequency of the sound generating device is also related to the size of the cavity structure 6.

[0080] In an exemplary embodiment, the sound-generating device may include only one cavity structure 6; or, the sound-generating device may include a plurality of cavity structures 6, so that a better sound effect can be achieved through the cooperation of the plurality of cavity structures.

[0081] There is an overlapping area between the orthographic projection of the cavity structure 6 on the substrate 1 and the orthographic projection of the second electrode layer 5 on the substrate 1 , and the size of the overlapping area is not limited here.

[0082] Exemplarily, the orthographic projection of the cavity structure 6 on the substrate 1 may overlap with a partial area of ​​the orthographic projection of the second electrode layer 5 on the substrate 1 .

[0083] In the embodiment of the present application, at least one cavity structure 6 is provided between the first electrode layer 2 and the first vibration sublayer 41 , so that the vibration layer 4 has an appropriate vibration space, thereby converting the electrical signal into the acoustic signal under the action of the electric field.

[0084] In some embodiments of the present application, the sound generating device comprises at least two cavity structures 6, Figure 4 As shown, the second electrode layer 5 includes a plurality of second sub-electrodes 51 having the same number as the cavity structures 6;

[0085] The second sub-electrodes 51 are electrically connected to each other; and / or the second sub-electrodes 51 are disconnected from each other.

[0086] In an exemplary embodiment, the second electrode film is patterned to form Figure 4The second electrode layer 5 shown, wherein the second electrode layer 5 may include a plurality of second sub-electrodes 51 and a plurality of traces 52 which are the same in number as the cavity structures 6 .

[0087] There is no limitation on the number and arrangement of the wirings 52 in the second electrode layer 5 , and the number and arrangement can be determined according to actual conditions.

[0088] In practical applications, there is an overlapping area between the orthographic projection of the second sub-electrode 51 on the substrate 1 and the orthographic projection of the area surrounded by the outer contour of the cavity structure 6 on the substrate 1. In the case where the first electrode layer 2 is a whole layer, the effective vibration size of the vibration layer 4 is determined by the size of the overlapping area. Usually, the orthographic projection of the second sub-electrode 51 on the substrate 1 and the orthographic projection of the area surrounded by the outer contour of the cavity structure 6 on the substrate 1 are set to completely overlap, so that the effective vibration size of the vibration layer 4 is the same as the size of the second sub-electrode 51 and the same as the size of the projection of the cavity structure 6, thereby simplifying the structure and simplifying the manufacturing process.

[0089] It should be noted that the second sub-electrodes 51 are electrically connected to each other; and / or the second sub-electrodes 51 are disconnected from each other, including three situations:

[0090] In the first case, refer to Figure 4 As shown, the second sub-electrodes 51 are electrically connected through wiring 52 so that when a voltage is applied to the second electrode layer 5, each second sub-electrode 51 has the same voltage, so that the frequency of the sound waves generated by the vibration layer 4 near each cavity structure 6 is the same.

[0091] In the second case, each second sub-electrode 51 is disconnected from each other, so that when a voltage is applied to the second electrode layer 5, each second sub-electrode 51 has a different voltage, and the frequencies of the sound waves generated by the vibration layer 4 near each cavity structure 6 are different by separately controlling each second sub-electrode 51. It can be understood that the sound-generating device provided in the embodiment of the present application can simultaneously provide sound with a certain bandwidth, and on this basis, the sound-generating device of the present application can be applied to directional sound-generating technology.

[0092] In the third case, some of the second sub-electrodes 51 are electrically connected, and some of the second sub-electrodes 51 are disconnected, wherein the frequencies of the sound waves generated by the vibration layer 4 near the cavity structure 6 corresponding to the electrically connected second sub-electrodes 51 are the same, and the frequencies of the sound waves generated by the vibration layer 4 near the cavity structure 6 corresponding to the disconnected second sub-electrodes 51 are different. The specific frequency can be determined according to actual needs.

[0093] In some embodiments of the present application, reference Figure 4 As shown, the sound-generating device further includes a hollow area L, and the hollow area L and the second electrode layer 5 are arranged on the same layer;

[0094] Part of the first vibration sublayer 41 and part of the second vibration sublayer 42 are in contact with each other through the hollow area L.

[0095] In practical applications, the hollow area L and the second electrode layer 5 are prepared in one patterning process. Specifically, the second electrode layer 5 and the hollow area L are obtained simultaneously by patterning the second electrode film. The size and contour shape of the hollow area L are determined by the second electrode layer 5.

[0096] In the embodiment of the present application, since the second electrode layer 5 is obtained after patterning, it is not a whole layer structure; and the effective utilization area of ​​the second electrode layer 5 is mainly in the area where the second sub-electrode 51 is located. In practical applications, the area of ​​the second electrode film other than the second electrode layer 5 is etched away to form a hollow area L, and a part of the first vibration sublayer 41 and a part of the second vibration sublayer 42 are in contact through the hollow area L, so that the bonding force between the second electrode layer 5 and the first vibration sublayer 41 and the second vibration sublayer 42 can be improved, effectively reducing the risk of separation of the second electrode layer 5 and the vibration layer 4, and improving the reliability of the sound-generating device.

[0097] In some embodiments of the present application, the orthographic projection shape of the cavity structure 6 on the substrate 1 includes a combination of one or more of a circle, a square, a rectangle, and a hexagon.

[0098] In some embodiments of the present application, the orthographic projection shape of the cavity structure 6 on the substrate 1 is the same as the orthographic projection shape of the second sub-electrode 51 on the substrate 1 .

[0099] Below Figure 1 The sound-generating device shown in the figure is taken as an example to illustrate the performance of the sound-generating device provided by the embodiment of the present application. Figure 1 The structure of the second electrode layer 5 of the sound-generating device is shown in FIG. Figure 4 shown.

[0100]

[0101]

[0102] Among them, fo is the center frequency of the sound-generating device, tm is the thickness of the vibration layer 4 along the direction perpendicular to the substrate 1, a is the radius of the cavity structure 6, Y0 is the Young's modulus of the material of the vibration layer 4, ρ is the density of the material of the vibration layer 4, and σ is the Poisson's ratio of the material of the vibration layer 4. Vmax is the maximum excitation voltage of the sound-generating device, T is the residual stress of the vibration layer 4, tg is the depth of the cavity structure 6 along the direction perpendicular to the substrate 1, and ε0 is the vacuum dielectric constant.

[0103] In practical applications, when the structure of the sound-generating device is determined, as shown in reference formula (2), since the Young's modulus Y0 of the material of the vibration layer 4, the thickness tm of the vibration layer 4 along the direction perpendicular to the substrate 1, the depth tg of the cavity structure 6 along the direction perpendicular to the substrate 1, the radius a of the cavity structure 6, and the vacuum dielectric constant ε0 are all determined values, when the voltages applied to the second electrode layer 5 and the first electrode layer 2 of the sound-generating device are different, the deformation caused by the vibration of the vibration layer 4 is different, thereby making the residual stress T and Poisson's ratio σ of the vibration layer 4 different. As shown in reference formula (1), the thickness tm of the vibration layer 4 along the direction perpendicular to the substrate 1, the radius a of the cavity structure 6, and the density ρ of the material of the vibration layer 4 are all fixed values. Due to the different applied voltages, the Poisson's ratio σ and the Young's modulus Y0 of the vibration layer 4 are different, thereby generating different sound frequencies.

[0104] It can be understood that the sound frequency of the sound-emitting device is related to the material of the vibration layer 4 (Young's modulus Y0, density ρ), the thickness tm of the vibration layer 4, the radius a of the cavity structure 6, the Poisson's ratio σ and Young's modulus Y0 of the material deformation when the vibration layer 4 vibrates, and the vibration process of the vibration layer 4 is controlled by the applied voltage.

[0105] It should be noted that Poisson's ratio σ refers to the ratio of the absolute value of the transverse normal strain to the axial normal strain when the material is subjected to unidirectional tension or compression, also called the transverse deformation coefficient, which is an elastic constant reflecting the transverse deformation of the material. Young's modulus is the elastic modulus along the longitudinal direction; in the elastic deformation stage of the material, its stress and strain are in direct proportion (i.e., it conforms to Hooke's law), and its proportional coefficient is called the elastic modulus.

[0106] In addition, since the second electrode layer 5 is located between the first vibration sublayer 41 and the second vibration sublayer 42, theoretically, the vibration of the second electrode layer 5 will also affect the sound frequency; however, in actual applications, the thickness of the second electrode layer 5 is much smaller than the thickness of the vibration layer 4, so the vibration of the second electrode layer 5 has a negligible effect on the sound frequency.

[0107] Figure 5 The graph shows the relationship between the thickness tm of the vibration layer 4 of the generating device and the radius a of the cavity structure 6 when the center frequencies are 10 kHz, 40 kHz and 75 kHz respectively, when the material of the vibration layer 4 is polyethylene terephthalate (PET). Figure 5 It can be seen from the curve relationship that, when the center frequency is determined, the radius a of the cavity structure 6 gradually increases with the increase of the thickness tm of the vibration layer 4.

[0108] It should be noted that the above formulas (1), (2) and Figure 5The radius a of the cavity structure 6 (when the projection shape of the cavity structure 6 is a circle) should actually be the radius of the area where the vibration layer 4 vibrates. Since the radius of the area where the vibration layer 4 vibrates is the same as the radius of the cavity structure 6, the embodiment of the present application is explained using the radius of the cavity structure 6 as an example.

[0109] In the sound-emitting device provided in the embodiment of the present application, the material of the vibration layer 4 is polyethylene terephthalate (PET), the thickness of the vibration layer 4 is less than or equal to 1 μm, and the radius a of the cavity structure 6 is about 20 μm. The center frequency range of the sound-emitting device is 3-5 MHz.

[0110] In some embodiments of the present application, reference Figure 3 As shown, the substrate 1 and the support layer 3 are an integrated structure; wherein a portion of the first electrode layer 2 contacts the surface of the substrate 1 close to the cavity structure 6 , and the remaining portion of the first electrode layer 2 contacts the surface of the support layer 3 away from the substrate 1 .

[0111] It should be noted that Figure 3 The dotted line between the substrate 1 and the support layer 3 is intended to illustrate that the integrated structure includes two parts, and does not represent the division of the integrated structure.

[0112] In the embodiment of the present application, by configuring the substrate 1 and the support layer 3 as an integrated structure, the structure can be simplified, the difficulty of the preparation process of the sound-generating device can be reduced, and the cost can be reduced.

[0113] In some embodiments of the present application, reference Figure 2a As shown, the sound-generating device further includes an adhesive layer, which is located between the substrate 1 and the support layer 3, and the substrate 1 and the support layer 3 are fixed by the adhesive layer (not shown in the figure);

[0114] Among them, the first electrode layer 2 covers the substrate 1, and a partial area of ​​the first electrode layer 2 is located between the substrate 1 and the supporting layer 3, the remaining area of ​​the first electrode layer 2 is located between the substrate 1 and the cavity structure 6, and the bonding layer covers the portion of the first electrode layer 2 located between the substrate 1 and the supporting layer 3.

[0115] It should be noted that in practical applications, reference Figure 2a As shown, the support layer 3 and the first vibrator layer 41 are also fixed together by an adhesive layer.

[0116] In an exemplary embodiment, the material of the bonding layer may include an adhesive, such as a heat-curing epoxy adhesive, a light-curing epoxy adhesive, or the like.

[0117] In some embodiments of the present application, materials of the substrate 1 , the first electrode layer 2 , the vibration layer 4 , and the second electrode layer 5 are all light-transmitting materials.

[0118] In practical applications, reference Figure 2b As shown, the second electrode layer 5 can also be arranged on the side of the vibration layer 4 close to the cavity structure 6. Compared with arranging the second electrode layer 5 between the first vibration sub-layer 41 and the second vibration sub-layer 42, as shown in FIG. Figure 2b The structure shown is simpler and can shorten the production cycle.

[0119] The embodiment of the present application provides a method for preparing the above sound-generating device, referring to Figure 6 As shown, the method includes:

[0120] S901, providing a substrate 1;

[0121] In an exemplary embodiment, the material of the substrate 1 may include a rigid material or a flexible material. For example, the rigid material may include glass, and the flexible material may include a flexible light-transmitting resin.

[0122] S902, forming a first electrode layer 2;

[0123] In the case where the first electrode layer 2 is conductive, the specific material of the first electrode layer 2 is not limited.

[0124] At least part of the first electrode layer 2 is in contact with the surface of the substrate 1 close to the vibration layer 4, and the first electrode layer 2 is a whole layer of thin film without patterning. Figure 3 As shown, a portion of the first electrode layer 2 is in contact with the surface of the substrate 1 close to the vibration layer 4; or, referring to Figure 2a As shown, all regions of the first electrode layer 2 are in contact with the surface of the substrate 1 close to the vibration layer 4 .

[0125] S903, forming a first vibration sublayer 41;

[0126] S904 , forming a second electrode layer 5 on the first vibration sublayer 41 ;

[0127] S905 , forming a second vibration sublayer 42 on the second electrode layer 5 ; the first electrode layer 2 is located on a side of the first vibration sublayer 41 away from the second vibration sublayer 42 , and at least a portion of the first electrode layer 2 contacts a surface of the substrate 1 close to the vibration layer 4 .

[0128] In an exemplary embodiment, the material of the vibration layer 4 may include a polymer material. Specifically, the material of the vibration layer 4 may include a combination of one or more of polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polyetherimide (PEI), polyimide (PI), polyethylene naphthalate (PEN), polyetheretherketone (PEEK) and polypropylene (PP).

[0129] In an exemplary embodiment, the first vibration sublayer 41 and the second vibration sublayer 42 are made of the same material, so that the structure and the manufacturing process can be simplified and the cost can be reduced.

[0130] In an exemplary embodiment, the first electrode layer 2 and the second electrode layer 5 may be made of different conductive materials. For example, the material of the first electrode layer 2 is ITO, and the material of the second electrode layer 5 is graphene.

[0131] The sound-generating device prepared by the preparation method of the embodiment of the present application has a simple structure, is easy to manufacture, has a low cost, and has a good sound-generating effect. In addition, since the second electrode layer 5 is disposed between the first vibration sublayer 41 and the second vibration sublayer 42, the second vibration sublayer 42 protects the second electrode layer 5 without affecting the vibration of the vibration layer 4, thereby reducing the risk of the second electrode layer 5 falling off during the vibration of the vibration layer 4.

[0132] Below Figure 2a Taking the structure shown in the figure as an example, the preparation method of the sound-generating device is specifically described.

[0133] S101. Provide Figure 7 The substrate 1 shown;

[0134] S102, forming a first electrode layer 2 on the substrate 1;

[0135] S103, provide Figure 8 The support film 30 shown is formed into a support layer 3 by etching or mechanical punching process;

[0136] S104, fix the support layer 3 on Figure 7 In the structure shown, the Fig. 9 The intermediate structure shown;

[0137] S105, forming a Fig.10 The first vibrating sublayer 41 is shown;

[0138] The first vibrator layer 41, the support layer 3 and the first electrode layer 2 together constitute Fig.10 In the cavity structure 6 shown, the support layer 3 can serve as the side wall of the cavity structure 6 , and the orthographic projection shape of the cavity structure 6 on the substrate 1 is determined by the support layer 3 .

[0139] The first vibrator layer 41 may be directly disposed on the support layer 3 , or may be bonded to the support layer 3 via a bonding layer, which is determined according to actual conditions.

[0140] S106, forming a second electrode layer 5 on the first vibrator layer 41;

[0141] The first electrode layer 2 and the second electrode layer 5 can be prepared by magnetron sputtering or vapor deposition, which is not limited here.

[0142] S107 , forming a second vibrator layer 42 on the second electrode layer 5 .

[0143] The first vibration sublayer 41 and the second vibration sublayer 42 may be formed by spin coating or spray coating.

[0144] In practical applications, the second vibration sub-layer 42 can serve as a protective film for the second electrode layer 5 , thereby reducing the risk of the second electrode layer 5 falling off when the vibration layer 4 vibrates.

[0145] Below Figure 3 Taking the structure shown in the figure as an example, the preparation method of the sound-generating device is specifically described.

[0146] S201, provide Fig.11 The substrate film 100 is shown;

[0147] S202, forming a cavity of a fixed depth and a fixed shape on the base film 100 by mechanical punching or laser punching, and the cavity does not penetrate the base film 100, so as to obtain Fig.12 The substrate 1 and the support layer 3 of the integrated structure shown;

[0148] S203, forming Fig.13 The first electrode layer 2 shown;

[0149] S204, forming Fig.14 The first vibration layer 41 is shown;

[0150] It should be noted that, in practical applications, the first vibration layer 41 can be formed on the substrate in advance by spin coating or spray coating and then solidified, and then the first vibration layer 41 is fixed on the support layer 3, and the specific fixing method is not limited here.

[0151] The subsequent steps are the same as steps S106-S107 in the previous text and will not be repeated here.

[0152] The embodiment of the present application also provides a display device, referring to Fig.15a As shown, it includes a display panel 300 and at least one sound-generating device 200 as described above;

[0153] The material of the sound-emitting device 200 includes a light-transmitting material; at least a portion of the light-emitting side substrate 1 of the display panel 300 is configured as a base 1 of the sound-emitting device 200 , and the first electrode layer 2 is located on the light-emitting surface of the display panel 300 .

[0154] Fig.15aThe structure of the display device shown is drawn by taking the entire area of ​​the light-emitting side substrate 1 of the display panel 300 as the base 1 of the sound-emitting device 200 as an example. In actual applications, for a large-sized display panel, the size of the sound-emitting device 200 is usually smaller than the size of the display panel 300. In this case, a partial area of ​​the light-emitting side substrate 1 of the display panel 300 is configured to serve as the base 1 of the sound-emitting device 200.

[0155] There is no restriction on the specific material of the base 1 (the light-emitting side substrate 1 of the display panel 300 ). Depending on the type of the display panel 300 , the light-emitting side substrate 1 of the display panel 300 can be made of different materials, which is determined according to actual conditions.

[0156] The specific structure of the above-mentioned display panel is not limited here. For example, it can be any one of an LCD (Liquid Crystal Display) display panel, an OLED (Organic Light-Emitting Diode) display panel, a Micro OLED micro display panel, and a Mini LED micro display panel. If the display panel is a liquid crystal display panel, the liquid crystal display panel can be a TN (Twisted Nematic) type, a VA (Vertical Alignment) type, an IPS (In-Plane Switching) type, or an ADS (Advanced Super Dimension Switch) type liquid crystal display panel.

[0157] The display device can be any product or component with a display function, such as a television, a digital camera, a mobile phone, a tablet computer, a bracelet, etc.

[0158] The display device provided by the embodiment of the present application is provided with a sound-emitting device 200 on the light-emitting side of the display panel 300, and the base 1 of the sound-emitting device 200 is shared with the substrate 1 on the light-emitting side of the display panel 300, so that the light-transmitting sound-emitting device 200 is integrated with the display panel 300, thereby realizing the synchronization of display and sound. In practical applications, the size and material of the sound-emitting device 200 can be adjusted according to the type of the display panel 300 to meet the sound requirements of different display devices.

[0159] In some embodiments of the present application, reference Fig.15b As shown, the size of the sound-generating device 200 is the same as the size of the display panel 300, and the sound-generating device 200 includes a cavity structure 6;

[0160] The display panel 300 includes a display area AA and a frame area B. The orthographic projection of the cavity structure 6 of the sound-emitting device 200 on the display panel 300 falls into the display area AA. The orthographic projection of the supporting layer 3 of the sound-emitting device 200 on the display panel 300 falls into the frame area B.

[0161] The display area AA refers to an area for displaying images, and the frame area B refers to other areas outside the display area AA.

[0162] The display device provided by the embodiments of the present application, especially for display devices such as mobile phones, bracelets, watches, etc., is arranged so that the orthographic projection of the cavity structure 6 of the sound-emitting device 200 on the display panel 300 falls into the display area AA, thereby reducing the propagation path of the light emitted from the display area AA of the display panel 300, improving the light output rate of the display light, and further improving the display effect.

[0163] In some embodiments of the present application, reference Fig.16 or Fig.17 As shown, the display device includes at least two sound generating devices 200, and the display area AA of the display panel 300 includes a plurality of opening areas K and non-opening areas (not marked in the figure) other than the opening areas K;

[0164] Wherein, in the case where the sound-generating device 200 includes a cavity structure 6, the orthographic projection of the supporting layer 3 of the sound-generating device 200 on the display panel 300 falls into the non-opening area;

[0165] In the case where the sound-generating device 200 includes at least two cavity structures 6 , the orthographic projection of the outer contour of the sound-generating device 200 on the display panel 300 falls into the non-opening area.

[0166] The opening area K refers to the area in the display area AA that can transmit light. It should be noted that for a conventional display panel, the display area AA is provided with structures that can shield light, such as a black matrix layer BM or metal wiring, and the area where these structures are located is called a non-opening area, and the area that can transmit light other than the non-opening area is called an opening area. Generally, the size of each opening area K is related to the size of the color filter layer or the light-emitting functional layer in the pixel.

[0167] In the display device provided by the embodiment of the present application, when the sound-emitting device 200 includes one cavity structure 6, the orthographic projection of the supporting layer 3 of the sound-emitting device 200 on the display panel 300 is set to fall into the non-opening area; when the sound-emitting device 200 includes at least two cavity structures 6, the orthographic projection of the outer contour of the sound-emitting device 200 on the display panel 300 is set to fall into the non-opening area. In this way, the path of the display light of at least part of the display panel 300 emitting from the display device from the opening area K can be shortened, the influence of the sound-emitting device 200 on the display light is reduced, and the display effect of the display device is improved.

[0168] In some embodiments of the present application, the sound-generating device 200 includes at least two cavity structures 6;

[0169] The two cavity structures 6 are configured to emit sound waves of different frequencies so that the display device can emit sound in a directionally oriented manner.

[0170] It should be noted that in practical applications, there are usually three ways to implement directional sound technology: the first is to add a sound-collecting cover to the outside of the traditional sound-emitting device. This technology is based on the principle of physical reflection and has a poor effect; the second is to increase the size of the traditional speaker, because whether the sound can be propagated in a direction is directly related to the size of the sound source. When the wavelength of the sound signal is close to the size of the sound source, the sound wave can show better directionality. The audible sound frequency is between 20Hz and 20kHz, and its wavelength is between 17mm and 17m. Obviously, it is impractical to design a huge speaker to achieve directional sound propagation; the third method is parametric array technology, which modulates the sound signal on the ultrasonic signal and then emits it through an ultrasonic transducer. This method can achieve directional sound propagation.

[0171] Among them, the premise of realizing directional sound emission through parametric array technology is that two frequency sound emission signals are required, namely, sound signal (frequency is 20Hz-20kHz) and ultrasonic signal (frequency is above 20kHz). In the related art, to realize directional sound emission technology, at least two sound emission devices need to be set up, one of which emits sound signal (frequency is 20Hz-20kHz) and the other emits ultrasonic signal (frequency is above 20kHz), so as to modulate the sound signal on the ultrasonic signal and then emit it through the ultrasonic transducer.

[0172] The display device provided in the embodiment of the present application can simultaneously emit sound signals of different frequencies by setting a sound-generating device 200, and then realize directional propagation of sound through parametric array technology, as follows:

[0173] In the first case, the second electrode layer 5 of the sound-generating device 200 includes a plurality of second sub-electrodes 51 having the same number as the cavity structures 6 ; the second sub-electrodes 51 are electrically connected to each other, and the sizes of the orthographic projections of the two cavity structures 6 on the substrate 1 are different.

[0174] In an exemplary embodiment, the different sizes of the orthographic projections of the two cavity structures 6 on the substrate 1 can be understood as: the equivalent sizes of the orthographic projections of the two cavity structures 6 on the substrate 1 are the same, including two situations: first, the shapes of the orthographic projections of the two cavity structures 6 on the substrate 1 are different, and the equivalent sizes are the same; second, the shapes of the orthographic projections of the two cavity structures 6 on the substrate 1 are the same, and the equivalent sizes are different.

[0175] In actual applications, the second sub-electrodes 51 are electrically connected so that the voltages applied to the areas of the vibration layer 4 corresponding to different cavity structures 6 are the same and their vibration frequencies are the same; since the sizes of the orthographic projections of the two cavity structures 6 on the substrate 1 are different, the sizes of the actual effective vibration areas of the vibration layer 4 are different (refer to the previous formula 1, which can be understood as different parameters a), so that in the same sound-emitting device, the sound frequencies of the areas of the vibration layer 4 corresponding to different cavity structures 6 are different, so that one sound-emitting device 200 can simultaneously emit sound signals of different frequencies.

[0176] In the second case, the second electrode layer 5 of the sound-generating device 200 includes a plurality of second sub-electrodes 51 which is the same in number as the cavity structures 6 ; the orthographic projections of the two cavity structures 6 on the substrate 1 have the same size, and the second sub-electrodes 6 are disconnected from each other.

[0177] In practical applications, the dimensions of the orthographic projections of the two cavity structures 6 on the substrate 1 are the same. Since the second sub-electrodes 6 are disconnected from each other, different voltages of different second sub-electrodes 6 can be set to control the vibration frequencies of the regions of the vibration layer 4 corresponding to each cavity structure 6 to be different, so that the Young's modulus Y0 and Poisson's ratio σ of the vibration layer 4 are different, thereby controlling the sound frequencies of the regions of the vibration layer 4 corresponding to different cavity structures 6 to be different, thereby enabling a sound-emitting device 200 to emit sound signals of different frequencies at the same time.

[0178] It should be noted that the premise of the above two cases is that the orthographic projection shape of the cavity structure 6 on the substrate 1 is the same as the orthographic projection shape of the second sub-electrode 6 on the substrate 1, and the size is also the same. In this way, the size of the actual effective vibration area of ​​the vibration layer 4 is the same as the projection size of the cavity structure 6.

[0179] Fig.18 A schematic diagram of a display device for achieving the sound effect of "sound and picture integration" is shown. Specifically, the display area AA of the display device is divided into six areas (respectively Fig.18 In the image, there are areas marked A1 to A6, each area is provided with an independent sound device 200. Before the video is played, the sound source file is divided into at least one channel applied to the six sound devices according to the position of the sound source in the video screen (the position of the sound source). When the video is played, it is played in different sound devices 200 according to the divided channels, thereby achieving the sound effect of "integration of sound and picture". The specific implementation process can refer to the relevant technology, which will not be repeated here.

[0180] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A sound-generating device, characterized in that: include: substrate; A first electrode layer, a vibration layer, and a second electrode layer located on the substrate; The vibration layer includes a first vibration sublayer and a second vibration sublayer, the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer, and at least a portion of the first electrode layer is in contact with a surface of the substrate close to the vibration layer, and the second electrode layer is located between the first vibration sublayer and the second vibration sublayer; The sound-generating device further includes a supporting layer and at least one cavity structure, wherein the supporting layer and the cavity structure are arranged in the same layer; wherein the supporting layer is located on a side of the first vibration sublayer away from the second vibration sublayer; the cavity structure is located between the first electrode layer and the first vibration sublayer, and an orthographic projection of the cavity structure on the substrate overlaps with an orthographic projection of the second electrode layer on the substrate; The first electrode layer covers the substrate, and a partial area of ​​the first electrode layer is located between the supporting layer and the substrate, and the remaining area is located between the substrate and the cavity structure; or, the substrate and the supporting layer are an integrated structure, and a partial area of ​​the first electrode layer is in contact with a surface of the substrate close to the cavity structure, and the remaining area of ​​the first electrode layer is in contact with a surface of the supporting layer away from the substrate.

2. The sound generating device according to claim 1, characterized in that: The sound-generating device comprises at least two of the cavity structures, and the second electrode layer comprises a plurality of second sub-electrodes having the same number as the cavity structures; Wherein, the second sub-electrodes are electrically connected to each other; and / or, the second sub-electrodes are disconnected from each other.

3. The sound-generating device according to claim 2, characterized in that: The sound-generating device further comprises a hollow area, and the hollow area and the second electrode layer are arranged on the same layer; A partial area of ​​the first vibration sublayer and a partial area of ​​the second vibration sublayer are in contact with each other through the hollow area.

4. The sound generating device according to claim 2, characterized in that: The orthographic projection shape of the cavity structure on the substrate includes a combination of one or more of a circle, a square, a rectangle, and a hexagon.

5. The sound generating device according to claim 4, characterized in that: The orthographic projection shape of the cavity structure on the substrate is the same as the orthographic projection shape of the second sub-electrode on the substrate.

6. The sound generating device according to claim 1, characterized in that: The sound-generating device further comprises a bonding layer, wherein the bonding layer is located between the substrate and the supporting layer, and the substrate and the supporting layer are fixed by the bonding layer; Wherein, the bonding layer covers a portion of the first electrode layer located between the substrate and the supporting layer.

7. The sound-generating device according to any one of claims 1 to 6, characterized in that: The substrate, the first electrode layer, the vibration layer and the second electrode layer are all made of light-transmitting materials.

8. A method for preparing a sound-generating device according to any one of claims 1 to 6, characterized in that: The method comprises: providing a substrate; forming a first electrode layer; forming a first vibrating sublayer; forming a second electrode layer on the first vibration sublayer; A second vibration sublayer is formed on the second electrode layer; the first electrode layer is located on a side of the first vibration sublayer away from the second vibration sublayer, and at least a portion of the first electrode layer contacts a surface of the substrate close to the vibration layer.

9. A display device, characterized in that: comprising a display panel and at least one sound-generating device according to any one of claims 1 to 6; The material of the sound-emitting device includes a light-transmitting material; at least a partial area of ​​the light-emitting side substrate of the display panel is configured to serve as the base of the sound-emitting device, and the first electrode layer is located on the light-emitting surface of the display panel.

10. The display device according to claim 9, characterized in that: The size of the sound-generating device is the same as the size of the display panel, and the sound-generating device includes a cavity structure; The display panel includes a display area and a frame area, the cavity structure of the sound-generating device has an orthographic projection on the display panel falling into the display area, and the supporting layer of the sound-generating device has an orthographic projection on the display panel falling into the frame area.

11. The display device according to claim 9, characterized in that The display device comprises at least two of the sound generating devices, and the display area of ​​the display panel comprises a plurality of opening areas and non-opening areas except the opening areas; Wherein, in the case where the sound-generating device includes one of the cavity structures, the orthographic projection of the supporting layer of the sound-generating device on the display panel falls into the non-opening area; In the case where the sound-generating device includes at least two of the cavity structures, the orthographic projection of the outer contour of the sound-generating device on the display panel falls into the non-opening area.

12. The display device according to any one of claims 9 to 11, characterized in that: The sound-generating device comprises at least two cavity structures; The two cavity structures are configured to emit sound waves of different frequencies so that the display device can emit sound in a directionally controlled manner.

13. The display device according to claim 12, characterized in that: The second electrode layer of the sound-generating device includes a plurality of second sub-electrodes having the same number as the cavity structures; The second sub-electrodes are electrically connected to each other, and the orthographic projections of the two cavity structures on the substrate have different sizes.

14. The display device according to claim 12, characterized in that: The second electrode layer of the sound-generating device includes a plurality of second sub-electrodes having the same number as the cavity structures; The orthographic projections of the two cavity structures on the substrate have the same size, and the second sub-electrodes are disconnected from each other.

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