CN116939441A

CN116939441A - Acoustic equipment

Info

Publication number: CN116939441A
Application number: CN202210339487.0A
Authority: CN
Inventors: 朱光远; 张磊; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2023-10-24
Also published as: TWI820888B; TW202341532A

Abstract

The embodiment of the specification discloses an acoustic device. The apparatus comprises: piezoelectric components, electrodes, and vibration components. Wherein the piezoelectric assembly vibrates under the action of the driving voltage, the electrodes provide the driving voltage for the piezoelectric assembly, and the vibration assembly is physically connected to the piezoelectric assembly, receives the vibration and generates sound. The piezoelectric assembly includes: the piezoelectric device comprises a substrate and a piezoelectric layer, wherein the piezoelectric layer is covered on one surface of the substrate, the electrode is covered on one surface of the piezoelectric layer, and the coverage area of the electrode on the surface of the piezoelectric layer is smaller than the area of the surface of the substrate covered with the piezoelectric layer. According to the mode control system, the mode actuator of the piezoelectric component is formed through electrode design, so that the piezoelectric component outputs a specific mode shape, the sound characteristic of the acoustic equipment is improved, and compared with a mode control system formed by adding different mechanical structures in a specific area, the mode control of the piezoelectric component is realized through electrode design, and the structure of the acoustic equipment can be simplified.

Description

Acoustic equipment

Technical Field

The present disclosure relates to the field of acoustic technologies, and in particular, to an acoustic device.

Background

The acoustic device may be deformed to transmit sound by applying electrical energy to the piezoelectric assembly. For example, the acoustic device may radiate sound waves outward by applying a driving voltage in a polarization direction of the piezoelectric assembly, generating vibration using an inverse piezoelectric effect of the piezoelectric material, and outputting the vibration through a vibration output point of the piezoelectric assembly.

However, piezoelectric components in acoustic devices have more vibrational modes in the audible frequency range and cannot form a flatter frequency response curve.

Therefore, there is a need for an acoustic device that is capable of controlling the vibrational modes of a piezoelectric assembly.

Disclosure of Invention

One of the embodiments of the present specification provides an acoustic device. The apparatus includes: piezoelectric components, electrodes, and vibration components. The piezoelectric assembly vibrates under the action of the driving voltage, the electrodes provide the driving voltage for the piezoelectric assembly, and the vibration assembly can be physically connected to the piezoelectric assembly, receives vibration and generates sound. The piezoelectric assembly may include: the piezoelectric device comprises a substrate and a piezoelectric layer, wherein the piezoelectric layer is covered on one surface of the substrate, the electrode is covered on one surface of the piezoelectric layer, and the coverage area of the electrode on the surface of the piezoelectric layer is smaller than the area of the surface of the substrate covered with the piezoelectric layer.

In some embodiments, the piezoelectric assembly includes a vibration output region.

In some embodiments, the piezoelectric assembly further comprises a fixation region.

In some embodiments, the piezoelectric assembly further comprises a vibration modulating assembly.

In some embodiments, the width of the electrode decreases gradually from the fixed region to the vibration output region.

In some embodiments, the electrode comprises two electrode envelope regions, the two electrode envelope regions being opposite in potential.

In some embodiments, there is a transition point between two electrode envelope regions, the electrode width in a first of the two electrode envelope regions gradually decreasing from the fixed region to the transition point.

In some embodiments, the electrode width in the second electrode envelope region of the two electrode envelope regions increases and then decreases from the transition point to the vibration output region.

In some embodiments, the width of the electrode at the fixed region is equal to the width of the fixed region.

In some embodiments, the width of the electrode at the vibration output region is 0.

In some embodiments, the piezoelectric layer is coincident with the substrate.

In some embodiments, the piezoelectric layer includes a piezoelectric region and a non-piezoelectric region.

In some embodiments, the piezoelectric region coincides with the electrode.

In some embodiments, the piezoelectric layer coincides with the electrode.

In some embodiments, the piezoelectric layer comprises a piezoelectric plate or a piezoelectric film.

In some embodiments, the electrode comprises a plurality of discrete electrode units distributed in two dimensions.

In some embodiments, the gap between two adjacent discrete electrode units at the center of the piezoelectric layer is smaller than the gap between two adjacent discrete electrode units at the boundary of the piezoelectric layer in the plurality of discrete electrode units.

In some embodiments, the area of the first discrete electrode unit at the center of the piezoelectric layer is greater than the area of the second discrete electrode unit at the boundary of the piezoelectric layer.

In some embodiments, the electrode comprises a two-dimensionally distributed continuous electrode comprising a plurality of hollowed-out areas thereon.

In some embodiments, the area of the first hollowed-out region at the center of the piezoelectric layer is smaller than the area of the second hollowed-out region at the boundary of the piezoelectric layer.

In some embodiments, the electrode also overlies another surface opposite the surface, and the area of coverage of the electrode on the other surface is less than or equal to the area of the surface.

In some embodiments, the vibration modulating assembly includes a mass physically connected to the vibration output region.

In some embodiments, the acoustic device further comprises a connector connecting the vibration assembly and the piezoelectric assembly.

In some embodiments, the acoustic device is a bone conduction audio device.

One of the embodiments of the present specification provides an acoustic device. The apparatus includes: piezoelectric components, electrodes, and vibration components. The piezoelectric assembly vibrates under the action of the driving voltage, the electrodes provide the driving voltage for the piezoelectric assembly, and the vibration assembly can be physically connected to the piezoelectric assembly, receives vibration and generates sound. The piezoelectric assembly may include: the piezoelectric layer covers on one surface of the substrate, the piezoelectric layer comprises a piezoelectric area and a non-piezoelectric area, wherein the electrode covers on one surface of the piezoelectric layer, and the substrate, the piezoelectric layer and the electrode are respectively overlapped. The coverage area of the piezoelectric region on the substrate is smaller than the coverage area of the piezoelectric layer on the substrate.

In some embodiments, the width of the piezoelectric region decreases gradually from the fixed region to the vibration output region.

In some embodiments, the piezoelectric region includes two piezoelectric envelope regions, the two electrode regions corresponding to the two piezoelectric envelope regions being opposite in potential.

In some embodiments, the width of the piezoelectric region at the fixed region is equal to the width of the fixed region.

In some embodiments, the width of the piezoelectric region at the vibration output region is 0.

In the embodiment of the specification, the mode actuator of the piezoelectric assembly can be formed through electrode design, so that the piezoelectric assembly only generates exciting force of a specific mode to output a specific mode shape, and the sound characteristic of the acoustic device is improved.

In addition, compared with a mode control system formed by adding different mechanical structures such as springs, masses and damping in a specific area, the mode control of the piezoelectric component can be realized based on electrode design, and the structure of the acoustic device is simplified.

Drawings

The present specification will be further elucidated by way of example embodiments, which will be described in detail by means of the accompanying drawings. The embodiments are not limiting, in which like numerals represent like structures, wherein:

FIG. 1 is a block diagram of an exemplary acoustic device shown in accordance with some embodiments of the present description;

FIG. 2 is a schematic structural diagram of an exemplary acoustic device shown in accordance with some embodiments of the present description;

FIG. 3 is a schematic structural view of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 4 is a partial schematic diagram of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present disclosure;

FIG. 5A is a schematic diagram of the structure of an exemplary first-order electrode shown in accordance with some embodiments of the present description;

FIG. 5B is a graph of a slope of a curve of an outer contour of an exemplary partial first-order electrode according to some embodiments of the present disclosure;

FIG. 5C is a schematic diagram of an exemplary second-order electrode shown in accordance with some embodiments of the present description;

FIG. 5D is a graph of the slope of the curve of the outer profile of an exemplary partial second-order electrode shown in accordance with some embodiments of the present description;

FIG. 6 is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 7A is a graph of the mode shape of the piezoelectric assembly at a second valley frequency when the electrode completely covers one surface of the piezoelectric assembly (i.e., the electrode coincides with the piezoelectric assembly);

FIG. 7B is a graph of vibration mode patterns of a piezoelectric assembly employing a first order electrode at a second order valley frequency according to some embodiments of the present disclosure;

FIG. 7C is a graph of vibration mode patterns of a piezoelectric assembly employing a second order electrode at a second order valley frequency according to some embodiments of the present description;

FIG. 8A is a schematic diagram of an electrode and piezoelectric assembly according to some embodiments of the present disclosure;

FIG. 8B is a schematic diagram of an electrode and piezoelectric assembly according to some embodiments of the present disclosure;

FIG. 8C is a schematic illustration of an electrode and piezoelectric assembly according to some embodiments of the present disclosure;

FIG. 8D is a schematic diagram of an exploded view of an electrode and piezoelectric assembly according to some embodiments of the present disclosure;

FIG. 9 is a schematic diagram of a frequency response curve of a piezoelectric assembly according to some embodiments of the present disclosure;

FIG. 10 is a schematic structural view of a piezoelectric assembly of an exemplary additional mass model shown in accordance with some embodiments of the present description;

FIG. 11A is a schematic diagram of the shape of an exemplary first-order electrode shown in accordance with some embodiments of the present description;

FIG. 11B is a schematic diagram of the shape of an exemplary second-order electrode shown in accordance with some embodiments of the present description;

FIG. 12 is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 13A is a graph of vibration mode of a piezoelectric assembly at a second order valley frequency with an additional mass model shown in some embodiments of the present description and with an electrode fully covering one surface of the piezoelectric assembly (i.e., the electrode coincides with the piezoelectric assembly);

FIG. 13B is a graph of vibration mode patterns of a piezoelectric assembly at a second order valley frequency using a first order electrode designed under an additional mass model, according to some embodiments of the present disclosure;

FIG. 13C is a graph of vibration mode at a second valley frequency of a piezoelectric component employing a design second order electrode without an attached mass model, according to some embodiments of the present disclosure;

FIG. 13D is a graph of vibration modes of a piezoelectric assembly employing an additional mass model for designing a second order electrode at a second order valley frequency, according to some embodiments of the present disclosure;

FIG. 14A is a schematic view of a portion of a two-dimensional electrode according to some embodiments of the present disclosure;

FIG. 14B is a schematic view of a portion of a two-dimensional electrode according to an exemplary embodiment of the present disclosure;

FIG. 14C is a schematic view of a portion of a two-dimensional electrode according to some embodiments of the present disclosure;

FIG. 14D is a schematic view of a portion of a two-dimensional electrode according to some embodiments of the present disclosure;

FIG. 15A is a comparative schematic of a frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 15B is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 15C is a schematic diagram of a vibration displacement at 5380.3Hz of a piezoelectric assembly covering an integral electrode, according to some embodiments of the present disclosure;

FIG. 15D is a schematic diagram of a vibratory displacement of a piezoelectric assembly covering an 8X 8 discrete electrode unit at 5380.3Hz, according to some embodiments of the present disclosure;

FIG. 16A is a first order mode shape diagram of a piezoelectric assembly with electrodes on the rectangular piezoelectric assembly fully covered (i.e., integral electrodes) according to some embodiments of the present disclosure;

FIG. 16B is a graph of vibration modes at high frequencies of a piezoelectric assembly with electrodes on the rectangular piezoelectric assembly fully covered (i.e., integral electrodes) as shown in some embodiments of the present disclosure;

FIG. 16C is a graph of vibration modes at high frequencies of a piezoelectric assembly employing discrete electrode units of 16X 8 two-dimensional electrodes on a rectangular piezoelectric assembly according to some embodiments of the present description;

FIG. 16D is a graph of vibration modes at high frequencies of a piezoelectric assembly employing discrete electrode units of 32X 16 two-dimensional electrodes on a rectangular piezoelectric assembly according to some embodiments of the present description;

FIG. 17A is a schematic diagram of a design concept of a discrete electrode unit of an exemplary two-dimensional electrode shown in accordance with some embodiments of the present description;

FIG. 17B is a schematic diagram of a discrete electrode unit of an exemplary two-dimensional electrode shown in accordance with some embodiments of the present description;

FIG. 17C is a schematic illustration of the shape of a rectangular corresponding first-order electrode equivalent to a two-terminal clamped beam, according to some embodiments of the present disclosure;

FIG. 18 is a vibration mode diagram of a piezoelectric assembly covering the two-dimensional electrode shown in FIG. 17B, according to some embodiments of the present disclosure;

FIG. 19A is a schematic view of a portion of a structure of an exemplary two-dimensional distribution of successive electrodes shown in accordance with some embodiments of the present disclosure;

FIG. 19B is a schematic view of a portion of a structure of an exemplary two-dimensional distribution of successive electrodes shown in accordance with some embodiments of the present disclosure;

FIG. 19C is a schematic view of a portion of a structure of an exemplary two-dimensional distributed continuous electrode shown in accordance with some embodiments of the present disclosure;

FIG. 20 is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 21 is a schematic diagram of an exemplary acoustic device shown in accordance with some embodiments of the present description;

FIG. 22 is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description;

FIG. 23A is a vibration mode diagram of an acoustic device employing integral electrodes according to some embodiments of the present description;

FIG. 23B is a diagram of vibration modes of an acoustic device employing first order electrodes according to some embodiments of the present description; and

fig. 24 is a schematic structural diagram of an exemplary acoustic device shown in accordance with some embodiments of the present description.

Wherein, 100, acoustic device; 110. a vibration assembly; 120. a piezoelectric assembly; 130. an electrode; 130-1, first-order electrodes; 130-2, second order electrodes; 123. a vibration output region; 121. a substrate; 122. a piezoelectric layer; 124. a fixed area; 131. a first electrode envelope region; 132. a second electrode envelope region; 133. a dot; 1221. a piezoelectric region; 1222. a non-piezoelectric region; 140. a mass block model; 141. a second vibration output region; 134. discrete electrode units; 1341. a first discrete electrode unit; 1342. a second discrete electrode unit; 1343. a third discrete electrode unit; 1344. a fourth discrete electrode unit; 171. a connecting piece; 172. a second shape; 135. a continuous electrode; 136. a hollowed-out area; 1361. a first hollowed-out area; 1362. the second hollowed-out area; 170. and a mass block.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present specification, and it is possible for those of ordinary skill in the art to apply the present specification to other similar situations according to the drawings without inventive effort. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

It will be appreciated that "system," "apparatus," "unit" and/or "module" as used herein is one method for distinguishing between different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As used in this specification and the claims, the terms "a," "an," "the," and/or "the" are not specific to a singular, but may include a plurality, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

A flowchart is used in this specification to describe the operations performed by the system according to embodiments of the present specification. It should be appreciated that the preceding or following operations are not necessarily performed in order precisely. Rather, the steps may be processed in reverse order or simultaneously. Also, other operations may be added to or removed from these processes.

The acoustic device of one or more embodiments of the present disclosure may output sound through vibration generated by the piezoelectric component, so as to be applied to various scenes where audio needs to be played, for example, the acoustic device may be an independent audio output device (such as a sound device, an earphone, etc.), and may play audio according to a user instruction; as another example, the acoustic device may be a module or component in a terminal device (such as a mobile phone, a computer, etc.), and may be capable of playing audio according to a terminal command. In some embodiments, the acoustic device may also adjust the deformation of the piezoelectric component to generate different vibrations according to parameters such as frequency and magnitude of the sound to be output, so that the vibration component outputs different sounds according to the different vibrations.

In some embodiments, the acoustic device may be a bone conduction acoustic device in which the vibration assembly may be conformable to the user's body tissue, and the sound waves emitted by the vibration assembly are transmitted through the user's bone to the user's inner ear. In some embodiments, the acoustic device may also be other types of acoustic devices, such as air conduction acoustic devices, hearing aids, glasses, helmets, augmented Reality (Augmented Reality, AR) devices, virtual Reality (VR) devices, etc., or alternatively, the acoustic device may be part of an in-vehicle audio system or an in-room sound system for outputting sound.

At present, piezoelectric components in acoustic devices have more vibration modes in an audible frequency range, and a relatively flat frequency response curve cannot be formed. In addition, piezoelectric components may also form nodes in the vibration output region at certain frequencies, affecting the effect of the acoustic output.

The present description embodiments describe acoustic devices. The acoustic device may include a piezoelectric assembly, an electrode, and a vibration assembly. The piezoelectric assembly vibrates under the action of the driving voltage, the electrodes provide the driving voltage for the piezoelectric assembly, and the vibration assembly can be physically connected to the piezoelectric assembly, receives vibration and generates sound. The piezoelectric assembly may include: a substrate and a piezoelectric layer. In some embodiments, the piezoelectric layer is overlaid on one surface of the substrate, the electrode is overlaid on one surface of the piezoelectric layer, and the area of coverage of the electrode on the surface of the piezoelectric layer is less than the area of the surface of the substrate overlaid with the piezoelectric layer. In some embodiments, a piezoelectric layer overlies a surface of a substrate and an electrode overlies a surface of the piezoelectric layer, the substrate, piezoelectric layer and electrode respectively coinciding. The piezoelectric layer comprises a piezoelectric region and a non-piezoelectric region, and the coverage area of the piezoelectric region on the substrate is smaller than that of the piezoelectric layer.

In addition, compared with a mode control system formed by adding mechanical structures such as springs, masses, damping and the like to a specific area, the mode control of the piezoelectric component can be realized based on electrode design, and the structure of the acoustic device is simplified.

Fig. 1 is a block diagram of an exemplary acoustic device 100, shown in accordance with some embodiments of the present description. In some embodiments, as shown in fig. 1, an acoustic device 100 may include: a vibration assembly 110, a piezoelectric assembly 120, and an electrode 130. Wherein the piezoelectric assembly 120 vibrates under the action of the driving voltage, the electrode 130 provides the driving voltage to the piezoelectric assembly 120, and the vibration assembly 110 may be physically (e.g., mechanically or electromagnetically) connected to the piezoelectric assembly 120, receives the vibration, and generates sound.

The vibration assembly 110 may be configured as an assembly that transmits vibrations and produces sound. In some embodiments, the vibration assembly 110 may include an elastic element that may deform in response to vibration, changing the sound pressure around itself, thereby generating sound waves, and enabling the output of sound. In some embodiments, the elastic element may include a vibration-transmitting sheet, glue, spring, or the like, or any combination thereof. In some embodiments, the material of the elastic element may be any material having the ability to transmit vibration energy. For example, the material of the elastic element may be silica gel, plastic, rubber, metal, etc., or any combination thereof. In some embodiments, the vibration component 110 may be a film-like structure (such as an air-conductive diaphragm, etc.), a plate-like structure (such as a bone-conductive vibration panel, etc.), or other structures such as a mesh-like structure or a layered structure.

An exemplary acoustic device 100 is provided below to describe a specific implementation of the vibration assembly 110.

Fig. 2 is a schematic structural diagram of an exemplary acoustic device 100 shown in accordance with some embodiments of the present description. As shown in fig. 2, one end of the vibration assembly 110 may be connected to the vibration output region 123 of the piezoelectric assembly 120 to receive vibrations. The other end of the vibration assembly 110 may output sound. Illustratively, the vibration assembly 110 may transmit sound waves to the user through one or more mediums (e.g., air, user bone, etc.), such that the user hears the sound output by the acoustic device 100.

The piezoelectric assembly 120 may be configured as an electrical energy conversion device that converts electrical energy into mechanical energy. In some embodiments, the piezoelectric assembly 120 may deform under the drive voltage to generate vibration. In some embodiments, the piezoelectric element 120 may be in the shape of a sheet, ring, prism, cuboid, column, sphere, etc., or any combination thereof, as well as other irregular shapes. In some embodiments, the piezoelectric assembly 120 may include a substrate 121 and a piezoelectric layer 122.

The substrate 121 may be configured as a carrier carrying the components and as an element that deforms in response to vibration. In some embodiments, the material of the substrate 121 may include: a combination of one or more of metals (e.g., copper clad, steel, etc.), phenolic resins, crosslinked polystyrene, etc. In some embodiments, the shape of the substrate 121 may be determined according to the shape of the piezoelectric assembly 120. For example, if the piezoelectric element 120 is a piezoelectric beam, the substrate 121 may be correspondingly configured to be elongated. For another example, if the piezoelectric element 120 is a piezoelectric film, the substrate 121 may be provided in a plate shape or a sheet shape.

The piezoelectric layer 122 may be a component configured to provide a piezoelectric effect and/or an inverse piezoelectric effect. In some embodiments, the piezoelectric layer 122 may cover one or more surfaces of the substrate 121, and deform under the action of the driving voltage to drive the substrate 121 to deform, so as to realize the output vibration of the piezoelectric assembly 120. In some embodiments, the piezoelectric layer 122 may be entirely a piezoelectric region, i.e., the piezoelectric layer 122 may be made of a piezoelectric material. In some embodiments, the piezoelectric layer 122 may include a piezoelectric region and a non-piezoelectric region. The piezoelectric region and the non-piezoelectric region are connected to form a piezoelectric layer 122. In some embodiments, the piezoelectric region is made of a piezoelectric material and the non-piezoelectric region is made of a non-piezoelectric material. In some embodiments, the piezoelectric material may include a piezoelectric crystal, a piezoelectric ceramic, a piezoelectric polymer, or the like, or any combination thereof. In some embodiments, the piezoelectric crystal may include a crystal, sphalerite, boracite, tourmaline, zincite, gaAs, barium titanate and its derivative structure crystals, KH2PO4, naKC4H4O 6-4H 2O (rochalte), and the like, or any combination thereof. In some embodiments, piezoelectric ceramics refer to piezoelectric polycrystals that are irregularly aggregated of fine grains obtained by solid phase reaction and sintering between particles of different materials. In some embodiments, the piezoelectric ceramic material may include Barium Titanate (BT), lead zirconate titanate (PZT), lead barium lithium niobate (PBLN), modified lead titanate (PT), aluminum nitride (AIN), zinc oxide (ZnO), or the like, or any combination thereof. In some embodiments, the piezoelectric polymer material may include polyvinylidene fluoride (PVDF) or the like. In some embodiments, the non-piezoelectric material may include ceramic, rubber. In some embodiments, the mechanical properties of the non-piezoelectric material may be similar to those of the piezoelectric material. In some embodiments, the specific implementation of the piezoelectric region and the non-piezoelectric region may refer to the related content shown in fig. 8A or 8D below, which is not described herein.

The electrode 130 may be configured as an element that provides a driving voltage for the piezoelectric assembly 120. In some embodiments, the electrode 130 may be a combination of one or more of a metal electrode (e.g., copper electrode, silver electrode, etc.), a redox electrode (e.g., pt|fe and Fe electrode, pt|mn MnO electrode), a refractory salt electrode (e.g., calomel electrode, mercury oxide electrode), etc. In some embodiments, the electrode 130 may be disposed on at least one surface of the piezoelectric layer 122, for example, may be disposed on two opposing surfaces of the piezoelectric layer 122. In some embodiments, the electrodes may be disposed on the surface of the piezoelectric layer 122 by one or more of coating, embedding, conforming, etc.

In some embodiments, the piezoelectric layer 122 may cover at least one surface of the substrate 121. In some embodiments, the electrode 130 may overlie at least one surface of the piezoelectric layer 122. Fig. 3 and 4 provide two exemplary acoustic devices 100 to describe the arrangement between the substrate 121, the piezoelectric layer 122, and the electrode 130.

Fig. 3 is a schematic structural diagram of an exemplary piezoelectric assembly 120 shown in accordance with some embodiments of the present description. As shown in fig. 3, the piezoelectric assembly 120 may be a piezoelectric cantilever. The substrate 121 may carry the piezoelectric layer 122 and the electrode 130 (shown as triangle-like areas). In some embodiments, electrodes 130 may be disposed on one or more surfaces of piezoelectric layer 122 to provide a driving voltage to piezoelectric layer 122. In some embodiments, the piezoelectric layer 122 may cover one or more surfaces of the substrate 121, and when the piezoelectric layer 122 is deformed under the driving voltage, the substrate 121 may be deformed accordingly, so that the vibration output region of the piezoelectric assembly 120 outputs vibration. For example, the piezoelectric layer 122 may cover only one surface of the substrate 121. As another example, as shown in fig. 3, two piezoelectric layers 122 may be respectively coated on two opposite surfaces of the substrate 121.

Fig. 4 is a schematic diagram of a portion of an exemplary piezoelectric assembly 120 according to some embodiments of the present description. As shown in fig. 4, the piezoelectric assembly 120 may be a piezoelectric plate (or a piezoelectric film). The substrate 121 may carry the piezoelectric layer 122 and the electrode 130 (shown as a plurality of two-dimensionally distributed squares). In some embodiments, the area of the piezoelectric layer 122 may be larger than the substrate 121 or smaller than the substrate 121. In some embodiments, electrodes 130 may be disposed on one or more surfaces of the piezoelectric plate to provide a driving voltage to the piezoelectric plate. In some embodiments, the piezoelectric layer 122 may cover one or more surfaces of the substrate 121, and when the piezoelectric layer 122 is deformed under the action of the driving voltage, the substrate 121 may be deformed accordingly, so that the vibration output area of the piezoelectric plate outputs vibration. For example, as shown in fig. 4, the piezoelectric layer 122 may cover only one surface of the substrate 121. For another example, two piezoelectric layers 122 may cover two corresponding surfaces of the substrate 121, respectively.

In some embodiments, the piezoelectric assembly 120 may include a vibration output region 123 for transmitting vibrations generated by the piezoelectric assembly 120 to the vibration assembly 110. In some embodiments, the vibration output region 123 may be a face, an edge, a point, etc. of the piezoelectric assembly 120, or any combination thereof. As shown in fig. 3, when the piezoelectric assembly 120 is a piezoelectric cantilever beam, a partial region of one edge or surface of the piezoelectric assembly 120 may be the vibration output region 123. As shown in fig. 4, in the case where the piezoelectric assembly 120 is a piezoelectric plate or a piezoelectric film, an inner region (e.g., a center region of a vibration plane) of the piezoelectric assembly 120 may be a vibration output region 123.

In some embodiments, the piezoelectric assembly 120 may also include a fixed region 124. Wherein the fixing region 124 serves to fix a portion of the piezoelectric assembly 120 and restrain the piezoelectric assembly 120 from vibrating within the region, so that most of the vibration of the piezoelectric assembly 120 can be output from the vibration output region 123. In some embodiments, the fixed region 124 may correspond to the vibration output region 123. As shown in fig. 3, when the piezoelectric element 120 is a piezoelectric cantilever, one end of the piezoelectric element 120 in the longitudinal direction may be a vibration output region 123, and the other end of the piezoelectric element corresponding to the vibration output region 123 in the longitudinal direction may be a fixed region 124. For another example, when the piezoelectric element 120 is a piezoelectric plate or a piezoelectric film, the vibration output region 123 may be an inner region of the piezoelectric element 120, and a boundary region of the piezoelectric element 120 may be the fixed region 124.

In some embodiments, the piezoelectric assembly 120 may not be provided with the fixing region 124, and may be capable of transmitting vibration through the vibration output region 123, so as to reduce the process flow and cost, and facilitate movement of the piezoelectric assembly 120.

In some embodiments, the vibration of the piezoelectric assembly 120 may include one or more vibration modes. Wherein the vibrational mode is an inherent vibrational characteristic of the structural system. In the case that the electrode shape is not designed, the vibration mode of the piezoelectric component 120 is more, so that the frequency response curve is unstable, and the vibration output area of the piezoelectric component 120 forms a node at certain frequencies, which affects the effect of acoustic output.

In some embodiments, the shape of the electrode 130 may be designed such that the electrode 130 forms a piezoelectric modal actuator to output an excitation force such that the piezoelectric assembly 120 produces only a particular mode. In some embodiments, the area of coverage of the electrode 130 on the surface of the piezoelectric layer 122 may be smaller than the area of the surface of the substrate 121 covered with the piezoelectric layer 122, thereby implementing an electrode design. For example, as shown in fig. 3, the area of the electrode 130 (shown as a triangle-like region) may be smaller than the area of the piezoelectric layer 122 and also smaller than the area of the substrate 121, wherein the piezoelectric layer 122 may overlap the substrate 121 (i.e., the coverage area of the piezoelectric layer 122 on the substrate 121 is the entire surface area of one surface of the substrate 121). As another example, as shown in fig. 4, the area of the electrode 130 (shown by a plurality of two-dimensionally distributed squares) may be smaller than the area of the piezoelectric layer 122 and also smaller than the area of the substrate 121, wherein the piezoelectric layer 122 may overlap with the substrate 121 (i.e., the coverage area of the piezoelectric layer 122 on the substrate 121 is the entire surface area of one surface of the substrate 121).

In some embodiments, the profile of the electrode 130 may be determined based on a vibration mode function of the vibration structure of the piezoelectric assembly 120, thereby performing modal control of the piezoelectric assembly 120. In some embodiments, the mode shape function of the piezoelectric assembly 120 may include a first order mode shape, a second order mode shape, and the like. Correspondingly, the electrode 130 may include a first-order electrode 130-1 corresponding to a first-order mode shape, a second-order electrode 130-2 corresponding to a second-order mode shape, and the like.

Two exemplary first-order electrodes 130-1 and second-order electrodes 130-2 are provided below, respectively, using the piezoelectric cantilever shown in fig. 3 as an example, to describe in detail a specific implementation of the electrode design.

Fig. 5A is a schematic diagram of an exemplary first-order electrode 130-1, according to some embodiments of the present description. Fig. 5B is a graph illustrating the slope of the curve of the outer profile of an exemplary partial first-step electrode 130-1, according to some embodiments of the present disclosure.

In some embodiments, the width of the electrode 130 may gradually decrease from the fixed region 124 to the vibration output region 123. The "width of the electrode 130" as referred to herein refers to the dimension of the electrode in the width direction of the piezoelectric assembly 120 (e.g., the width direction of the piezoelectric cantilever). Here, the width of the electrode 130 at a certain position (d 1, d2 as shown in fig. 5A) may be a distance between two intersections of a line perpendicular to the central axis of the piezoelectric assembly 120 in the length direction at the position and the outer contour line of the electrode 130. In some embodiments, the gradual decrease in width of the electrode 130 from the fixed region 124 to the vibration output region 123 may include one or any combination of a gradient decrease, a linear decrease, or a curvilinear decrease in width. As shown in fig. 5A, the width of the first-stage electrode 130-1 may decrease curvilinearly from the left side (i.e., the fixed region 124) to the right side (i.e., the vibration output region 123). As shown in fig. 5B, the absolute value of the slope of the curve of the outer contour line of the first-stage electrode 130-1 along the portion above the central axis gradually decreases from the vibration fixing region 124 as the length increases to 0 at the vibration output region 123. In some embodiments, the electrodes 130 may be symmetrically disposed, e.g., the electrodes 130 may be symmetrical along a central axis of the piezoelectric assembly 120. In some embodiments, the electrodes 130 may also be asymmetrically disposed. In some embodiments, the shape curve (i.e., the outer contour) of the electrode 130 may be one or any combination (e.g., a linear combination) of a trigonometric function (e.g., a sine function, a cosine function, etc.), a hyperbolic function (e.g., a hyperbolic sine function, a hyperbolic cosine function, etc.).

Fig. 5C is a schematic diagram of an exemplary second-order electrode 130-2 shown in accordance with some embodiments of the present description. Fig. 5D is a graph of a slope of a curve of an outer profile of an exemplary partial second-order electrode 130-2 shown in accordance with some embodiments of the present disclosure.

In some embodiments, the electrode 130 may include two electrode envelope regions, the two electrode envelope regions being opposite in potential. The electrode envelope region may be a region where the conductive medium of the electrode 130 is located, and the potential of the electrode envelope region may be a voltage across the electrode envelope region. For example, as shown in fig. 5C, the voltage across the first electrode envelope 131 of the second-order electrode 130-2 may be positive and the voltage across the second electrode envelope 132 may be negative. Alternatively, the voltage across the first electrode envelope 131 may be negative and the voltage across the second electrode envelope 132 may be positive.

In some alternative embodiments, when the polarization directions of the two electrode envelope regions are the same, the potentials in opposite directions circumscribing the two electrode envelope regions may be controlled such that the potentials of the two electrode envelope regions are opposite. In some alternative embodiments, when the polarization directions of the two electrode envelope regions are opposite, the same electric potential circumscribing the two electrode envelope regions may be controlled such that the electric potentials of the two electrode envelope regions are opposite.

In some embodiments, a transition point 133 may be present between two electrode envelope regions, and the electrode width in the first electrode envelope region 131 of the two electrode envelope regions may gradually decrease from the fixed region 124 to the transition point 133.

In some embodiments, the transition point 133 may be a point where the potential between the electrode envelope regions is 0, and the potential directions of the regions on both sides of the point (i.e., the two electrode envelope regions) are opposite. In some embodiments, the transition points 133 may be used to distinguish between electrode envelope regions. For example, the electrode envelope region between the fixed region 124 to the transition point 133 may be the first electrode envelope region 131. Here, the width of the electrode in the first electrode envelope region 131 (d 3 shown in fig. 5C) may be a distance between two intersections of a line perpendicular to the central axis of the piezoelectric assembly 120 in the length direction at that position and the outer contour line of the electrode 130. In some embodiments, the electrode width reduction in the first electrode envelope region 131 may include one or any combination of a gradient reduction, a linear reduction, or a curvilinear reduction.

For example, as shown in fig. 5C, when the electrode 130 is a second-order electrode 130-2, the potential of the switching point 131 may be 0, and the potentials of the first electrode envelope region 131 and the second electrode envelope region 132 are opposite. Also, the width of the first electrode envelope region 131 may decrease curvilinearly from the left side (i.e., the fixed region 124) to the transition point 133. As shown in fig. 5D, in the first electrode envelope region 131, the absolute value of the curve slope of the outer contour line of the second-order electrode 130-2 along the portion above the central axis gradually decreases with an increase in length from the vibration fixing region 124 to the transfer point 133.

In some embodiments, the electrode width in the second electrode envelope 132 of the two electrode envelope increases and then decreases from the transition point 133 to the vibration output region 123. The width of the electrode in the second electrode envelope region 132 (d 4 shown in fig. 5C) may be a distance between two intersections of a line perpendicular to the central axis of the piezoelectric assembly 120 in the length direction and the outer contour line of the electrode 130 at that position. In some embodiments, the electrode envelope region between the transition point 133 to the vibration output region 123 may be the second electrode envelope region 132. In some embodiments, the electrode width in the second electrode envelope region 132 increases and then decreases may include one or more decreasing patterns such as a gradient change, a linear change, or a curvilinear change. For example, as shown in fig. 5C, the electrode width in the second electrode envelope region 132 may increase curvilinearly starting from the left side (i.e., the transition point 133), with the increasing magnitude becoming smaller and smaller until the width reaches the peak and then starts to decrease curvilinearly, until the vibration output region 123. As shown in fig. 5D, in the second electrode envelope region 132, the absolute value of the curve slope of the outer contour line of the second-order electrode 130-2 along the portion above the central axis decreases from the transition point 133 first as the length increases, to the widest point of the second electrode envelope region 132 where the curve slope decreases to 0, and then increases and then decreases as the length increases, to the vibration output region 123 where the absolute value of the curve slope decreases to 0.

In some embodiments, the electrode 130 may further include one or more of a third electrode envelope region, a fourth electrode envelope region, and the like, the shape and number of which may be determined according to the vibration mode of the piezoelectric assembly 120 to be controlled.

In some embodiments, the width of the electrode 130 at the fixed region 124 may be equal to the width of the fixed region 124. As shown in fig. 5A and 5C, the width of the fixing region 124 may be D, and correspondingly, the width of the electrode 130 in the fixing region 124 may also be D.

In some alternative embodiments, the width of the electrode 130 at the fixing region 124 may not be equal to the width of the fixing region 124, e.g., the width of the electrode 130 may be smaller than the width of the fixing region 124 or may be larger than the width of the fixing region 124.

In some embodiments, the width of the electrode 130 at the vibration output region 123 may be 0. As shown in fig. 5A and 5C, the width of the electrode 130 at the vibration output region 123 may be 0.

In some alternative embodiments, the width of the electrode 130 at the vibration output region 123 may be other than 0. For example, the width of the electrode 130 at the vibration output region 123 may be smaller than the width of the electrode 130 at the fixed region 124 and larger than 0.

Fig. 6 is a comparative schematic diagram of the frequency response curves of an exemplary piezoelectric assembly according to some embodiments of the present description. As shown in fig. 6, curve 1 is a frequency response curve of the piezoelectric element 120 at the vibration output area when the electrode 130 completely covers one surface of the piezoelectric element 120 (i.e., the electrode 130 coincides with the piezoelectric element 120). Curve 2 is the frequency response curve of the piezoelectric element 120 employing the first-order electrode configuration shown in fig. 5A, and curve 3 is the frequency response curve of the piezoelectric element 120 employing the second-order electrode configuration (with opposite electric potentials of the two envelope regions) shown in fig. 5C.

As shown in fig. 6, curve 1 has a first-order peak and a second-order valley, reflecting that when electrode 130 completely covers one surface of piezoelectric component 120 (i.e., electrode 130 coincides with piezoelectric component 120), piezoelectric component 120 has a relatively complex vibration mode in the mid-high frequency range, and in particular has a significantly different vibration response in the range of 500Hz to 3000 Hz. After the first-order electrode form is adopted, the first-order modal frequency band of the piezoelectric component 120 shown in the curve 2 is prolonged, the second-order valley disappears, a narrow-band jump of the curve is generated at the second-order peak frequency (such as the vicinity of 3000 Hz), and the amplitude of the second-order peak is reduced. In this manner, the first-order electrode 130-1 is disposed in such a manner that the vibrational response of the piezoelectric element 120 between the first-order peak and the second-order peak becomes flatter. After the second-order electrode 130-2 is used (and the two envelope regions are opposite in potential), the frequency response curve of the piezoelectric element 120 shown in curve 3 is in the second-order mode from the low-frequency stage (e.g., 0-100 Hz), and a narrow-band jump of the curve is generated at the first-order peak frequency (e.g., between 500Hz and 600 Hz), so that the amplitude of the first-order peak is reduced. After the peak frequency, the second order mode is set up to the third order peak frequency (e.g., 9000 hz). In this way, the second-order electrode 130-2 is disposed in such a manner that the piezoelectric element 120 is in a second-order array from the low-frequency stage to the third-order peak. As can be seen from curves 2 and 3, the first and second electrode configurations (and the opposite potentials of the two envelope regions) have a modal control effect. The "peak frequency" in this specification refers to the peak (e.g., first order peak, second order peak, third order peak, etc.) frequency of the piezoelectric assembly 120 when the electrode 130 completely covers one surface of the piezoelectric assembly 120 (i.e., the electrode 130 coincides with the piezoelectric assembly 120).

Further, as shown in fig. 6, curve 4 is a frequency response curve of the piezoelectric component 120 employing the second-order electrode 130-1 (and the electric potentials of the two envelope regions are the same) as shown in fig. 5C; curve 5 is a plot of the frequency response of the piezoelectric assembly 120 using a triangular electrode (i.e., an isosceles triangle formed by the fixed region 124 of the piezoelectric assembly 120 and the center point of the vibration output region 123 as the shape of the electrode). With the triangular electrode, the frequency response curve of the piezoelectric element 120 shown in curve 5 still has a second order valley, but the second order valley is significantly shifted back compared to the curve 1 completely covered by the electrode. In this way, the triangular electrode 130 may be disposed in such a manner that the response of the piezoelectric element 120 between the first-order peak frequency and the second-order valley frequency becomes flatter. With the second-order electrode 130-2 (and the two envelope regions are at opposite potential), the frequency response curve of the piezoelectric assembly 120 shown in curve 4 is similar to curve 1 (electrode 130 completely covers one surface of the piezoelectric assembly 120).

FIG. 7A is a graph of the mode shape of the piezoelectric assembly 120 at a second order valley frequency when the electrode completely covers one surface of the piezoelectric assembly (i.e., the electrode coincides with the piezoelectric assembly); FIG. 7B is a graph of vibration modes of the piezoelectric assembly 120 at a second valley frequency using the first-order electrode 130-1 according to some embodiments of the present disclosure; fig. 7C is a graph of vibration modes of the piezoelectric assembly 120 at a second valley frequency using the second-order electrode 130-2 according to some embodiments of the present description.

Referring to fig. 6 and 7A-7C, at second order Gu Pinlv (e.g., 1622 Hz), when the electrode completely covers one surface of the piezoelectric assembly (i.e., the electrode coincides with the piezoelectric assembly), the fluctuation of the vibration response of the piezoelectric assembly 120 is large and the frequency response curve is uneven. The vibration response of the piezoelectric element 120 with the electrode design (e.g., the first-order electrode 130-1 or the second-order electrode 130-2) has smaller fluctuation, and the frequency response curve is flatter, so that the node is less likely to be formed.

In the embodiment of the present disclosure, the electrode 130 may be designed to form a mode actuator of the piezoelectric assembly 120, so that the piezoelectric assembly 120 generates only excitation force of a specific mode to output a specific mode shape, thereby improving the acoustic characteristics of the acoustic device. In addition, the frequency response curve of the piezoelectric component 120 can be more stable, so that the formation of nodes in the vibration output area 123 of the piezoelectric component 120 is avoided, and the operational reliability of the acoustic device 100 is improved.

In addition, compared with a mode control system formed by adding mechanical structures such as springs, masses, damping and the like to a specific area, the mode control of the piezoelectric assembly 120 can be realized based on the electrode 130 design in the embodiment of the specification, and the structure of the acoustic device 100 is simplified.

In some embodiments, the piezoelectric assembly 120 may also be designed according to the design of the electrode 130. A specific embodiment of designing the piezoelectric assembly 120 is described in detail below using a number of exemplary designs employing one-dimensional first-order electrodes 130-1.

FIG. 8A is a schematic diagram of an electrode 130 and a piezoelectric assembly 120 according to some embodiments of the present disclosure; FIG. 8B is a schematic diagram of the electrode 130 and the piezoelectric element 120 according to some embodiments of the present disclosure; FIG. 8C is a schematic diagram of the electrode 130 and the piezoelectric element 120 according to some embodiments of the present disclosure; fig. 8D is a schematic diagram illustrating an exploded structure of the electrode 130 and the piezoelectric element 120 according to some embodiments of the present disclosure. It should be understood that the triangular areas (or triangularly-like areas) in fig. 8A-8D are for illustration only and are not intended to limit the shape of the electrodes.

In some embodiments, as shown in fig. 3, the substrate 121 may be rectangular, the piezoelectric layer 122 may be a piezoelectric rectangular beam (the piezoelectric layer 122 is all piezoelectric regions) coincident with the substrate 121, and the electrode 130 may be a first-order electrode 130-1, i.e., the coverage area of the electrode 130 (shown as a triangle-like region) < the coverage area of the piezoelectric layer 122 = the surface area of the substrate 121 covering the piezoelectric layer 122.

In some embodiments, as shown in fig. 8A, the substrate 121 may be rectangular, the piezoelectric layer 122 may be a piezoelectric rectangular beam coincident with the substrate 121, and the electrode 130 may be a first-order electrode 130-1. The piezoelectric layer 122 includes a piezoelectric region 1221 (made of a piezoelectric material) and a non-piezoelectric region 1222 (made of a non-piezoelectric material), wherein the piezoelectric region 1221 coincides with the first-order electrode 130-1 (the broken line inside the piezoelectric region 1221 is only used to distinguish between the piezoelectric region 1221 and the electrode 130 and is not used to define the size of both), i.e., the coverage area of the electrode 130 (shown as a triangle-like region) =the coverage area of the piezoelectric region 1221 < the coverage area of the piezoelectric layer 122=the surface area of the substrate 121 covering the piezoelectric layer 122.

In some embodiments, as shown in fig. 8B, the substrate 121 may be rectangular, the electrode 130 may be a first-order electrode 130-1, and the piezoelectric layer 122 may overlap with the electrode 130, and the coverage area is smaller than the surface area of the substrate 121 covering the piezoelectric layer 122, i.e., the coverage area of the electrode 130 (shown as a triangle-like area) =the coverage area of the piezoelectric layer 122 < the surface area of the substrate 121 covering the piezoelectric layer 122. That is, the piezoelectric material in the uncovered areas of the electrodes in the piezoelectric layer 122 is removed, leaving the substrate as a rectangular beam.

In some embodiments, as shown in fig. 8C, the electrode 130 may be a first-order electrode 130-1, and both the substrate 121 and the piezoelectric layer 122 may coincide with the electrode 130, i.e., the coverage area of the electrode 130 (shown as a triangle-like region) =the coverage area of the piezoelectric layer 122=the surface area of the substrate 121 covering the piezoelectric layer 122.

In some embodiments, the piezoelectric layer 122 may coincide with the substrate 121. For example, as shown in fig. 3 or fig. 8C, the coverage area of the piezoelectric layer 122=the surface area of the substrate 121 covering the piezoelectric layer 122. In some alternative embodiments, the piezoelectric layer 122 may not coincide with the substrate 121. For example, as shown in fig. 8B, the area of the piezoelectric layer 122 may be smaller than the area of the substrate 121.

In some embodiments, the piezoelectric layer 122 may be entirely a piezoelectric region. For example, as shown in fig. 3, 8B, or 8C, the piezoelectric layer 122 may be entirely supported by a piezoelectric material. In some embodiments, the piezoelectric layer 122 may include a piezoelectric region 1221 and a non-piezoelectric region 1222. For example, as shown in fig. 8A, the piezoelectric layer 122 includes a piezoelectric region 1221 made of a piezoelectric material and a non-piezoelectric region 1222 made of a non-piezoelectric material, and the area of the piezoelectric layer 122 is equal to the sum of the area of the piezoelectric region 1221 and the area of the non-piezoelectric region 1222.

In some embodiments, the piezoelectric region 1221 may coincide with the electrode 130. For example, as shown in fig. 8A, the piezoelectric region 1221 in the piezoelectric layer 122 is equal to the coverage area of the electrode 130, and the spatial positions overlap each other.

In some embodiments, the piezoelectric layer 122 may coincide with the electrode 130. For example, as shown in fig. 8B or 8C, the coverage area of the piezoelectric layer 122 is equal to the coverage area of the electrode 130, and the spatial positions overlap each other.

In some embodiments, the effective electrode portion of the electrode 130 may be configured to create a particular mode for the piezoelectric assembly 120 by the shape of the electrode 130 and the coverage of the piezoelectric region. For example, the piezoelectric layer 122 may include a piezoelectric region made of a piezoelectric material and a non-piezoelectric region made of a non-piezoelectric material. The sum of the areas of the piezoelectric region and the non-piezoelectric region is equal to the coverage area of the piezoelectric layer 122 on the substrate 121, and the substrate 121 and the piezoelectric layer 122 overlap. The sum of the areas of the piezoelectric and non-piezoelectric regions is equal to the area covered by electrode 130 on piezoelectric layer 122, i.e., electrode 130 and piezoelectric layer 122 overlap. In some embodiments, the coverage area of the piezoelectric region on the substrate 121 may be smaller than the coverage area of the piezoelectric layer 122 on the substrate 121. For example, as shown in fig. 8D, the substrate 121 may be rectangular, the piezoelectric layer 122 may be a piezoelectric rectangular beam overlapping the substrate 121, and the electrode 130 may be a rectangular electrode. The piezoelectric layer 122 includes a piezoelectric region 1221 and a non-piezoelectric region 1222, wherein the shape and area of the piezoelectric region 1221 (shown as a diagonal fill region) is used to define the effective area of the rectangular electrode 130, i.e., the area of the piezoelectric region 1221 < the coverage area of the piezoelectric layer 122 = the coverage area of the electrode 130 = the surface area of the substrate 121 covering the piezoelectric layer 122. The partial electrode 130 covered on the piezoelectric region 1221 may provide the driving voltage to the piezoelectric element 120, that is, the partial electrode 130 may be an effective electrode portion, and the partial electrode 130 covered on the non-piezoelectric region 1222 may transmit electric energy only as a conductive element for the effective electrode portion, so that the coverage area of the piezoelectric region 1221 on the substrate 121 may be regarded as the area of the effective region of the electrode 130. In this manner, the design of the electrode 130 may be achieved by designing the piezoelectric region 1221 such that a portion of the electrode 130 overlying the piezoelectric region 122 may control the piezoelectric assembly 120 to output a particular mode.

Fig. 9 is a schematic diagram of a frequency response curve of the piezoelectric assembly 120 according to some embodiments of the present disclosure. In some embodiments, curve 6 is the frequency response curve of piezoelectric assembly 120 when the rectangular electrode completely covers one surface of the rectangular piezoelectric assembly (i.e., the electrode, piezoelectric assembly, and substrate all overlap). Curve 7 is a frequency response curve of the piezoelectric element 120 shown in fig. 3 (i.e., the coverage area of the electrode 130 < the coverage area of the piezoelectric layer 122=the surface area of the substrate 121 covering the piezoelectric layer 122), curve 8 is a frequency response curve of the piezoelectric element 120 shown in fig. 8A or 8D (i.e., the coverage area of the electrode 130=the coverage area of the piezoelectric region 1221 < the coverage area of the substrate 121 covering the piezoelectric layer 122 or the piezoelectric region area < the coverage area of the piezoelectric layer 122=the coverage area of the substrate 121 covering the piezoelectric layer 122), curve 9 is a frequency response curve of the piezoelectric element 120 shown in fig. 8B (i.e., the coverage area of the electrode 130=the coverage area of the substrate 121 covering the piezoelectric layer 122), and curve 10 is a frequency response curve of the piezoelectric element 120 shown in fig. 8C (i.e., the coverage area of the electrode 130=the coverage area of the piezoelectric layer 122=the surface area of the substrate 121 covering the piezoelectric layer 122).

As shown in fig. 9, when the electrode completely covers one surface of the piezoelectric element (i.e., the electrode coincides with the piezoelectric element), the frequency response curve of the piezoelectric element 120 shown in curve 6 has a first order peak and a second order valley, and the piezoelectric element 120 has multiple modes. Curve 7 is similar to the frequency response of curve 8 in that the replacement of the piezoelectric material in the uncovered areas of the electrodes with non-piezoelectric material (or the shape of the piezoelectric area defining the effective area of the electrodes) may reflect similar characteristics for the frequency response curve as compared to the piezoelectric material in its entirety. The frequency response amplitude of the curve 9 is significantly improved, the low-frequency peak is moved to high frequency, the second-order mode is significantly suppressed, and the transition to the third-order valley is smoothly performed, so that the piezoelectric material in the uncovered region of the electrode 130 is removed, the piezoelectric layer 122 is overlapped with the electrode 130, and the mode control function can be performed when the coverage area of the piezoelectric layer 122 (or the electrode 130) is smaller than the surface area of the substrate 121 covering the piezoelectric layer 122. The frequency response curve shown in curve 10 still has first-order peaks and second-order valleys, and still has multiple modes, which can reflect the coincidence of the frequency response characteristics of the substrate 121, piezoelectric layer 122, and electrode 130 when they are all in the shape of the first-order electrode 130-1, and when the electrodes completely cover one surface of the piezoelectric element (i.e., the electrodes coincide with the piezoelectric element). Thus, the shape of the first-order electrode 130-1 may have an effect on the vibration mode of the rectangular piezoelectric cantilever, but cannot have a control effect on the vibration mode of the piezoelectric cantilever of the same shape (e.g., the shape of the first-order electrode 130-1).

In some embodiments, the potential distribution of the piezoelectric layer 122 is covered with the first-order electrode 130-1, and the potential distribution of the piezoelectric layer 122 is the same rule as when the piezoelectric region 1221 is covered with the first-order electrode 130-1 and the other region of the piezoelectric layer 122 is replaced with the non-piezoelectric region 1222 made of a non-piezoelectric material. For example, after the vibration frequency of the piezoelectric assembly 120 is about 100Hz, there is no potential difference in the region of the piezoelectric layer 122 uncovered by the first-order electrode 130-1 in the piezoelectric assembly 120 as shown in fig. 3, and the material of the uncovered region of the electrode 130 on the piezoelectric layer 122 is replaced with a non-piezoelectric material as shown in fig. 8A, the non-piezoelectric region uncovered by the electrode has no electrical property.

In the embodiment of the present disclosure, the piezoelectric component 120 may be designed according to the design of the electrode 130, and the area of the piezoelectric component 120 uncovered by the electrode may be replaced by a non-piezoelectric material from the piezoelectric material, so that the manufacturing cost of the piezoelectric component 120 is reduced while the piezoelectric component 120 is ensured to be capable of outputting vibration normally.

Fig. 10 is a schematic diagram of a piezoelectric assembly 120 of an exemplary additional mass model 140 shown in accordance with some embodiments of the present description.

In some embodiments, the vibration output region of the piezoelectric assembly 120 may be coupled to the vibration assembly 110 and/or other assemblies. In some embodiments, the vibration component 110 and/or other components may be reduced to a mass model 140 to design the profile of the electrode 130. Illustratively, as shown in FIG. 10, the vibration output region 123 of the piezoelectric assembly 120 is connected to the mass model 140. Wherein the mass model 140 may transmit vibrations and output the vibrations through its own second vibration output region 141. In some embodiments, the second vibration output region 141 may include a face, an edge, a point, etc. of the mass model 140, or any combination thereof. As shown in fig. 10, the second vibration output region 141 may include a center point of the mass model 140. The specific implementation of the second vibration output region 141 may refer to the related descriptions in fig. 3 to 4, and will not be repeated here.

In some embodiments, the contour curve of the electrode 130 may be determined based on the mass relationship of the piezoelectric assembly 120 and the mass model 140, as well as the vibration structure of the piezoelectric assembly 120, for modal control of the piezoelectric assembly 120. In some embodiments, the mass relationship of the piezoelectric assembly 120 and the mass model 140 may include a ratio of the mass model 140 to the mass of the piezoelectric assembly 120, i.e., the mass ratio α. For example, the mass ratio α may include 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, etc. Taking the piezoelectric cantilever beam shown in fig. 10 as an example, several exemplary first-order electrodes 130-1 and second-order electrodes 130-2 are provided, respectively, to describe in detail a specific implementation of the mass ratio.

Fig. 11A is a schematic diagram of the shape of an exemplary first-order electrode 130-1 shown according to some embodiments of the present description. Fig. 11B is a schematic diagram of the shape of an exemplary second-order electrode 130-2 shown in accordance with some embodiments of the present description.

As shown in fig. 11A, the curve 11 is the contour curve of the first-order electrode 130-1 when the mass model 140 has an additional mass ratio α=0.5, the curve 12 is the contour curve of the first-order electrode 130-1 when the mass model 140 has an additional mass ratio α=1, the curve 13 is the contour curve of the first-order electrode 130-1 when the mass model 140 has an additional mass ratio α=2. As shown in fig. 11B, the curve 14 is the contour curve of the second-order electrode 130-2 when the mass model 140 has an additional mass ratio α=0.5, the curve 15 is the contour curve of the second-order electrode 130-2 when the mass model 140 has an additional mass ratio α=1, and the curve 16 is the contour curve of the second-order electrode 130-2 when the mass model 140 has an additional mass ratio α=2.

In some embodiments, as the mass ratio α varies, the shape of the electrode 130 may also vary. For example, the greater the mass ratio α of the mass model 140 to the mass of the piezoelectric assembly 120, the more the width of the electrode 130 is changed. Illustratively, as shown in FIG. 11A, from curve 11 to curve 13, the mass model 140 has a mass to piezoelectric assembly 120 mass ratio α that is greater and greater, and the profile curve of the first-order electrode 130-1 has a smaller degree of curvature, i.e., the profile curve of the first-order electrode 130-1 has a flatter and flatter change.

As another example, as shown in fig. 11B, from curve 14 to curve 16, the mass ratio α of the mass model 140 to the mass of the piezoelectric element 120 is larger and the degree of curvature of the profile curve of the second-order electrode 130-2 is smaller and smaller from the fixed region 124 to the transition point 133. Also, the degree of curvature of the profile curve of the second-order electrode 130-2 increases from the transition point 133 to the vibration output region 123, and the degree of curvature decreases as it decreases, i.e., the profile curve of the second-order electrode 130-2 changes straighter. The specific implementation of the contour curves of the electrode 130 may be referred to in the relevant descriptions of fig. 5A-5D, and will not be repeated here.

In some embodiments, in the case where the piezoelectric assembly 120 is attached with the mass model 140, the contour curve of the electrode 130 may be determined only according to the vibration structure of the piezoelectric assembly 120 without considering the mass relationship between the piezoelectric assembly 120 and the mass model 140, and the piezoelectric assembly 120 may also be subjected to modal control. Specific implementation of electrode design without considering mass ratio can be referred to the following description in fig. 12-13D, and will not be repeated here.

Fig. 12 is a comparative schematic of the frequency response curves of an exemplary piezoelectric assembly according to some embodiments of the present description.

As shown in fig. 12, curve 17 is a frequency response curve of the piezoelectric element 120 with the mass model 140 attached when the electrode 130 completely covers one surface of the piezoelectric element 120 (i.e., the electrode 130 coincides with the piezoelectric element 120, both are rectangular). Curve 18 is the frequency response curve of the mass model 140 with the additional mass ratio α=0.5 and the piezoelectric element 120 using the first-order electrode 130-1 as shown in fig. 11A, curve 19 is the frequency response curve of the mass model 140 with the additional mass ratio α=1 and the piezoelectric element 120 using the first-order electrode 130-1 as shown in fig. 11A, curve 20 is the mass model 140 with the additional mass ratio α=2 and the frequency response curve of the piezoelectric element 120 using the first-order electrode 130-1 as shown in fig. 11A, curve 21 is the frequency response curve of the piezoelectric element 120 using the first-order electrode 130-1 (i.e., the electrode shape calculated without the additional mass model 140) but with the additional mass ratio α=0.5, and curve 22 is the frequency response curve of the mass model 140 with the additional mass ratio α=0.5 and the piezoelectric element 120 using the second-order electrode 130-2 as shown in fig. 11B.

As shown in fig. 12, the presence of the first and second order peaks of the curve 17 may reflect that the piezoelectric assembly 120 of the additional mass model 140 still has multiple modes when the electrode 130 completely covers one surface of the piezoelectric assembly 120 (i.e., the electrode 130 coincides with the piezoelectric assembly 120).

As shown in FIG. 12, after the first-order electrode 130-1 designed under the additional mass model 140 is used, the piezoelectric element 120 shown in the curve 18-20 starts from the first-order peak and smoothly transitions to the second-order peak frequency (e.g., around 1000 Hz), where only weak transitions occur, and then continues to smoothly transition to the third-order valley. Also, the amplitude of the frequency response curve of the piezoelectric assembly 120 shown by curve 18-20 decreases significantly at both the second order peak frequency and the third order peak frequency (e.g., around 7000 Hz).

And, as the mass ratio α increases, the frequency corresponding to the first-order peak of the frequency response curve of the piezoelectric component 120 shown in the curve 18-20 is lower, the amplitude from the first-order peak to the rear is lower, and the change trend of the frequency response curve after hopping at the second-order peak frequency is flatter, which can reflect that the larger the mass ratio α, the better the mode control effect of the piezoelectric component 120 adopting the first-order electrode 130-1 designed under the additional mass block model 140.

As shown in fig. 12, after the first-order electrode 130-1 designed under the unattached mass model 140 is adopted, the frequency response curve of the piezoelectric component of the mass model 140 with the attached mass ratio α=0.5 shown in the curve 21 can be smoothly transited at the frequency corresponding to the second-order valley, but the amplitude and bandwidth of the jump at the second-order peak frequency are obviously increased, which can reflect that the first-order electrode 130-1 designed under the unattached mass model 140 can still realize the modal control of the second-order valley of the piezoelectric component 120, but the suppression effect on the high-order modal may be weakened.

After the second-order electrode 130-2 designed under the additional mass model 140 is used, the frequency response curve of the piezoelectric element 120 shown in curve 22 is similar to the frequency response curve of the piezoelectric element 120 shown in curve 3 in fig. 6 above, which is not the additional mass model 140, starting from the low frequency phase (e.g., 0-100 Hz), i.e., in the second-order mode, and generating a narrow-band jump of the curve at the first-order peak frequency (e.g., between 100Hz and 200 Hz), reducing the first-order peak amplitude. After the peak frequency, the piezoelectric assembly 120, which is designed with the mass model 140 having the additional mass ratio α=0.5, can control the second order mode, while the second order electrode 130-2 (with opposite electric potentials in the two envelope regions) is at the second order mode up to the third order peak frequency (e.g., between 6000Hz and 7000 Hz).

FIG. 13A is a graph of the vibration mode of piezoelectric assembly 120 at a second order valley frequency when an additional mass model 140 is shown and the electrodes completely cover one surface of piezoelectric assembly 120 (i.e., electrode 130 coincides with piezoelectric assembly 120) in accordance with some embodiments of the present description; FIG. 13B is a graph of the vibration mode of the piezoelectric assembly 120 at the second order valley frequency using the first order electrode 130-1 designed under the additional mass model 140, according to some embodiments of the present disclosure; FIG. 13C is a graph of the mode shape of the piezoelectric assembly 120 at the second order valley frequency using the non-attached mass model 140 for designing the second order electrode 130-2, according to some embodiments of the present disclosure; fig. 13D is a graph of the mode shape of the piezoelectric assembly 120 at the second order valley frequency using the additional mass model 140 design second order electrode 130-2, according to some embodiments of the present disclosure.

Referring to fig. 12 and 16A-16D, when the electrode completely covers one surface of the piezoelectric assembly (i.e., the rectangular electrode coincides with the rectangular piezoelectric assembly) at the second order Gu Pinlv (e.g., 1411 Hz), the vibration response of the piezoelectric assembly 120 of the additional mass model 140 fluctuates greatly during vibration, the frequency response curve is uneven, and the vibration output region 123 may form a node at some frequencies, affecting the effect of the acoustic output. With the first-order electrode 130-1 designed under the additional mass model 140 (or the first-order electrode 130-1, the second-order electrode 130-2 designed under the additional mass model 140 or the first-order electrode 130-1 designed under the non-additional mass model 140), the vibration response of the piezoelectric component 120 of the additional mass model 140 fluctuates less during the vibration process, the frequency response curve is flatter, and the node is less likely to be formed.

In addition, as shown in fig. 13C, when the first-order electrode 130-1 designed under the non-additional mass model 140 is used, the piezoelectric component 120 of the additional mass model 140 may show a tendency of transition to the second-order mode during vibration, which may reflect that the first-order electrode 130-1 designed under the non-additional mass model 140 may still achieve mode control of the piezoelectric component 120, but may reduce the suppression effect on the higher-order mode.

In the embodiment of the present disclosure, the electrode 130 is designed based on the mass ratio α of the mass model 140 and the piezoelectric assembly 120, so that the piezoelectric assembly 120 can generate more accurate excitation force of a specific mode, thereby further improving the mode control effect. In addition, the amplitude of the frequency response curve of the piezoelectric component 120 at the fixed frequency can be reduced, so that the node formed by the vibration output area 123 of the piezoelectric component 120 is avoided, and the working reliability of the acoustic device 100 is further improved.

In some embodiments, the piezoelectric assembly 120 may include a piezoelectric plate or a piezoelectric film. In some embodiments, the shape of the electrode 130 may be determined according to the size of the piezoelectric plate or film and the mode shape function of the vibrating structure. For example, the covered electrode 130 on the piezoelectric plate or film may be designed as a plurality of discrete electrode units (which may also be referred to as "two-dimensional electrodes") distributed in two dimensions, causing the piezoelectric assembly 120 to generate a particular mode shape.

An exemplary discrete electrode unit 134 and continuous electrode are provided below, respectively, using the piezoelectric assembly 120 shown in fig. 4 as an example, to describe in detail a specific implementation of a two-dimensional electrode design.

In some embodiments, the electrode 130 may include a plurality of discrete electrode units 134 distributed in two dimensions. In some embodiments, the plurality of discrete electrode units 134 may be configured to be separated from each other and to distribute the conductive material over the surface of the piezoelectric assembly 120. In some embodiments, the shape of the discrete electrode unit 134 may include one or any combination of circles, triangles, quadrilaterals, irregularities, and the like.

FIG. 14A is a schematic view of a portion of an exemplary two-dimensional electrode 130 according to some embodiments of the present disclosure; FIG. 14B is a schematic view of a portion of an exemplary two-dimensional electrode 130 shown in accordance with some embodiments of the present disclosure; FIG. 14C is a schematic illustration of a partial structure of an exemplary two-dimensional electrode 130 according to some embodiments of the present disclosure; fig. 14D is a schematic diagram of a portion of an exemplary two-dimensional electrode 130 according to some embodiments of the present disclosure.

Fig. 14A shows a quarter of a square piezoelectric layer, where the piezoelectric layer 122 (e.g., a square piezoelectric sheet having a size of 18×18×0.09 mm) is overlapped with the substrate 121 (e.g., a steel substrate having a size of 18×18×0.05 mm), and the peripheral edge of the substrate is a fixed region 124. Fig. 14B shows a quarter of a square piezoelectric layer, a piezoelectric layer 122 (for example, a square piezoelectric sheet having a size of 18×18×0.09 mm) is covered on a substrate 121 (for example, a steel substrate having a size of 23×23×0.05 mm), the covered area of the piezoelectric layer 122 is smaller than the area of the surface of the substrate 121 on which the piezoelectric layer is covered, and the peripheral edge of the substrate is a fixed area 124. Fig. 14C and 14D each show a rectangular piezoelectric layer, where the piezoelectric layer 122 (e.g., a rectangular piezoelectric plate having a size of 40×20×0.5 mm) is overlapped with the substrate 121 (e.g., a steel substrate having a size of 40×20×0.1 mm), and the peripheral edge of the substrate is a fixed region 124. The rectangular piezoelectric plate shown in fig. 14D is of a (3, 1) mode. In the present specification, "3" in "(3, 1) modes" means a third-order mode in the length direction, that is, a third-order mode when the rectangular piezoelectric plate is reduced to a cantilever beam (neglecting the presence of width) in the length direction; "1" means that the width direction is a first order mode, i.e., that the rectangular piezoelectric plate has a first order mode when simplified into a cantilever beam (neglecting the existence of the length) in the width direction.

In some embodiments, the gap between two adjacent discrete electrode units 134 at the center of the piezoelectric layer 122 is smaller than the gap between two adjacent discrete electrode units 134 at the boundary of the piezoelectric layer 122 among the plurality of discrete electrode units 134. The "center of the piezoelectric layer 122" described herein may be the geometric center of the piezoelectric layer 122, or may be the vibration amplitude output position of each order mode of the piezoelectric layer 122, or may be the center of the vibration output region 123. For example, when the piezoelectric layer 122 is in the (3, 1) mode, the center of the piezoelectric layer 122 may include 3 vibration centers each corresponding to the first-order vibration mode. Accordingly, the "boundary of the piezoelectric layer 122" described herein may be a geometric boundary of the piezoelectric layer 122, or may be a region where vibration output of each order mode of the piezoelectric layer 122 is minimum, or may be a boundary of the fixed region 124. For example, when the piezoelectric layer 122 is in the (3, 1) mode (i.e., the length direction is in the third-order mode, and the width direction is in the first-order mode), the boundary of the piezoelectric layer 122 may be the boundary of the region corresponding to each vibration mode. For example, as shown in fig. 14A to 14C, the gap between two adjacent discrete electrode units 134 at the geometric center of the piezoelectric layer 122 is a distance D1, and the gap between two adjacent discrete electrode units 134 at the boundary may be a distance D2, the distance D1 being smaller than the distance D2. As another example, as shown in fig. 14D, the gap between the adjacent two discrete electrode units 134 at each vibration center of the piezoelectric layer 122 is a distance D1, and the gap between the adjacent two discrete electrode units 134 at the boundary of the region corresponding to the vibration center may be a distance D2, the distance D1 being smaller than the distance D2. In some embodiments, the gap between adjacent two discrete electrode units increases gradually from the center of the piezoelectric layer 122 to the boundary. For example, the gap between two adjacent discrete electrode units near the center of the piezoelectric layer 122 is smaller than the gap between two adjacent discrete electrode units far from the center of the piezoelectric layer 122.

In some embodiments, the size of the area of the discrete electrode unit 134 may be related to the amount of vibrational displacement of the region in which it is located at a particular frequency (e.g., first order peak, second order peak). The vibration displacement amount refers to a change in distance of the piezoelectric layer 122 during vibration compared to a horizontal plane when not vibrating. In some embodiments, the area of the first discrete electrode unit 1341 at the center of the piezoelectric layer 122 is greater than the area of the second discrete electrode unit 1342 at the boundary of the piezoelectric layer 122. For example, as shown in fig. 14A to 14D, since the first discrete electrode unit 1341 is closer to the vibration output region 123 than the second discrete electrode unit 1342, the displacement amount of the first discrete electrode unit 1341 is larger than the displacement amount of the second discrete electrode unit 1342 during vibration, the area of the first discrete electrode unit 1341 may be larger than the area of the second discrete electrode unit 1342.

In some embodiments, the area of the discrete electrode unit 134 may be sized according to a difference (e.g., a displacement ratio) between the vibration displacement amount of the region where the discrete electrode unit 134 is located and the maximum displacement amount of the piezoelectric layer 122 at a specific frequency (e.g., a first peak, a second peak). For example, the piezoelectric layer 122 may be discretized into m×n piezoelectric subregions, i.e., m×n discrete electrode units 134. The discrete electrode units 134 of the piezoelectric subregions are determined by scaling the piezoelectric subregions equally based on the difference in displacement amount of each piezoelectric subregion and the maximum displacement amount of the piezoelectric layer 122.

In some embodiments, the potential of the discrete electrode unit 134 may be related to the direction of displacement of the piezoelectric subregion in which it is located. For example, as shown in fig. 14D, if the displacement direction of the third discrete electrode unit 1343 is opposite to the maximum displacement direction of the piezoelectric layer 122 and the displacement direction of the fourth discrete electrode unit 1344 is the same as the maximum displacement direction of the piezoelectric layer 122 during vibration of the piezoelectric assembly 120, the potential direction of the third discrete electrode unit 1343 is opposite to the potential direction of the fourth discrete electrode unit 1344.

The difference in frequency response curves when different shapes or numbers of discrete electrode units are respectively covered thereon will be described below by taking the size of the piezoelectric element 120 and the substrate shown in fig. 14A and 14B as an example.

FIG. 15A is a comparative schematic of a frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description; FIG. 15B is a comparative schematic of the frequency response curve of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description; FIG. 15C is a schematic diagram of a vibration displacement at 5380.3Hz of a piezoelectric assembly covering an integral electrode, according to some embodiments of the present disclosure; fig. 15C is a schematic diagram of vibration displacement at 5380.3Hz of a piezoelectric assembly covering 8 x 8 discrete electrode units, according to some embodiments of the present description.

As shown in fig. 15A, curve 23 is a frequency response curve of the piezoelectric element 120 when the electrode 130 completely covers one surface (i.e., the whole electrode) of the piezoelectric element 120 when the piezoelectric layer 122 shown in fig. 14A is overlapped with the substrate 121; curve 24 is a frequency response curve of the piezoelectric assembly 120 covered with 8×8 discrete electrode units 134 when the piezoelectric layer 122 is overlapped with the substrate 121 as shown in fig. 14A; curve 25 is a frequency response curve of the piezoelectric assembly 120 covered with the 32×32 discrete electrode units 134 when the piezoelectric layer 122 is overlapped with the substrate 121 as shown in fig. 14A.

As shown in fig. 15A, the frequency response curve of the piezoelectric element 120 shown in the curve 23 generates a resonance valley, and a split vibration is generated at a frequency (for example, about 5380.3 Hz) corresponding to the resonance valley, which can be reflected in that when the electrode 130 completely covers one surface of the piezoelectric element 120, the central area of the piezoelectric layer 122 is opposite to the peripheral vibration, and the vibration area is the same, which easily causes the radiation sound pressure of the piezoelectric element 120 to cancel out in the opposite phase in the vibration output area, and the vibration is difficult to output.

The frequency response curve of the piezoelectric assembly 120 shown in the curve 24-curve 25 can form a smooth sound pressure level frequency response curve between a first-order peak (such as 3500 Hz) and a second-order peak (such as about 10000 Hz), and promote the amplitude near the resonance valley frequency, so that the two-dimensional electrode 130 can reflect the expansion of the frequency bandwidth of the piston vibration of the piezoelectric assembly 120, so that the frequency corresponding to the original resonance valley (such as about 5380.3 Hz) still maintains the first-order piston vibration, and effectively outputs radiation sound pressure, thereby realizing modal control. The term "piston vibration" in this specification means that each region of the piezoelectric element 120 (e.g., piezoelectric plate) exhibits simultaneous up and down vibration (the same displacement direction) when vibrating, as does a piston.

In addition, the low frequency amplitude of the frequency response curve of the piezoelectric element 120 shown in the curves 24-25 is also improved before the first-order peak (e.g. before 2000 Hz), the overall bandwidth of the second-order peak and the following resonance valley (e.g. after 10000 Hz) is also reduced, which can reflect that the two-dimensional electrode 130 can improve the low frequency response of the piezoelectric element 120 and inhibit the natural mode shape of the piezoelectric element 120 at the second-order peak frequency.

Furthermore, the frequency response curve of the piezoelectric element 120 shown in the curve 25 has a higher low frequency response amplitude before the first peak (e.g. before 2000 Hz) than the frequency response curve of the piezoelectric element 120 shown in the curve 24, and further suppresses the amplitude and bandwidth at the second peak frequency (e.g. around 10000 Hz), which may reflect that the piezoelectric element 120 using the 32×32 two-dimensional electrode 130 may have a higher low frequency response than the 8×8 two-dimensional electrode 130, and may also suppress the high frequency mode.

As shown in fig. 15B, curve 23' is a frequency response curve of the piezoelectric element 120 when the electrode 130 completely covers one surface (i.e., the whole electrode) of the piezoelectric element 120 when the coverage area of the piezoelectric layer 122 shown in fig. 14B is smaller than the surface of the substrate 121 covering the piezoelectric layer; curve 24' is a frequency response curve of the piezoelectric assembly 120 covered with the 8×8 discrete electrode unit 134 when the coverage area of the piezoelectric layer 122 is smaller than the area of the surface of the substrate 121 covered with the piezoelectric layer as shown in fig. 14B; curve 25' is a frequency response curve of the piezoelectric assembly 120 covered with the 32×32 discrete electrode unit 134 when the coverage area of the piezoelectric layer 122 is smaller than the area of the surface of the substrate 121 covered with the piezoelectric layer as shown in fig. 14B.

As shown in fig. 15B, the frequency response curve of the piezoelectric component 120 shown by the curve 23' generates divided vibration at 4189.8Hz, and the vibration mode is similar to the curve 23, so that the sound pressure of the vibration output region is cancelled out in opposite phase, forming a resonance valley. According to the curve 24 'and the curve 25', the two-dimensional electrode can expand the vibration frequency band of the piston, and the two-dimensional electrode is still positioned in the vibration of the piston at the original resonance valley frequency point, so that the sound pressure level is smoothly transited in the frequency band. The frequency response curve of the piezoelectric assembly 120 shown in curve 23' is a flat curve at a sound pressure level around 6000Hz after the second order peak, while the two-dimensional electrode rear curve 24' and curve 25' are used to form a resonant valley. The reason for this phenomenon is that, with respect to the whole electrode, the vibration mode here is resonance of the portion of the substrate 121 beyond the piezoelectric layer 122, thereby outputting vibration. The two-dimensional electrode changes the vibration mode of the piezoelectric layer 122, and forms a vibration mode of opposite-phase vibration in the middle area and the peripheral area when elastically coupled with the edge substrate 121, and generates opposite-phase cancellation of sound pressure in the vibration output area, which is represented as a resonance valley on the curve, and has a certain influence on directivity.

As shown in fig. 15C and 15D, the piezoelectric element 120 generates divided vibration at 5380.3Hz when the whole electrode is covered, and the vibration of the middle region and the surrounding region are inverted and have the same area, resulting in the cancellation of the inversion of the sound pressure of the vibration output region; while the piezoelectric assembly 120 still vibrates for the piston at 5380.3Hz when covering the two-dimensional electrodes of the 8×8 discrete electrode units 134, the sound pressure is effectively output, and the sound pressure level amplitude of the vibration output area is remarkably improved.

FIG. 16A is a first order mode shape diagram of the piezoelectric assembly 120 with the electrodes on the rectangular piezoelectric assembly 120 fully covered (i.e., integral electrodes) according to some embodiments of the present disclosure; FIG. 16B is a graph of vibration modes at high frequencies of the piezoelectric assembly 120 when the electrodes on the rectangular piezoelectric assembly 120 are fully covered (i.e., integral electrodes) as shown in some embodiments of the present disclosure; FIG. 16C is a graph of vibration modes at high frequencies of a piezoelectric assembly 120 employing discrete electrode units 134 of 16 x 8 two-dimensional electrodes 130 on a rectangular piezoelectric assembly 120 according to some embodiments of the present disclosure; fig. 16D is a graph of vibration modes at high frequencies of a piezoelectric assembly 120 employing discrete electrode units 134 of 32 x 16 two-dimensional electrodes 130 on a rectangular piezoelectric assembly 120 according to some embodiments of the present description.

FIG. 16A illustrates a first order mode at 6907Hz for a rectangular piezoelectric assembly 120 employing integral electrodes; the rectangular piezoelectric assembly 120 employing integral electrodes exhibits a mode shape at a higher frequency 18326Hz as shown in fig. 16B. By covering the two-dimensional electrode 130, the mode shape at 18326Hz exhibits a first order mode shape similar to that of fig. 16A. Since 32×16 discrete electrode units are more than 16×8 discrete electrode units and more nearly continuously vary, the piezoelectric assembly 120 covering 32×16 discrete electrode units has a mode shape at 18326Hz that is more nearly the first order mode shape.

In the present embodiment, the design of the two-dimensional electrode 130 is implemented using the two-dimensional distribution of the plurality of discrete electrode units 134, so that the piezoelectric assembly 120 can output only a specific mode shape, further improving the sound characteristics of the acoustic device 100.

In addition, the frequency response curve of the piezoelectric component 120 can be more stable, so that the node formation of the vibration output area 123 caused by the vibration inversion of the middle area and the surrounding area of the piezoelectric component 120 is avoided, and the working reliability of the acoustic device 100 is improved.

FIG. 17A is a schematic diagram of a design concept of discrete electrode units 134 of an exemplary two-dimensional electrode 130 shown in accordance with some embodiments of the present disclosure; FIG. 17B is a schematic diagram of the structure of discrete electrode units 134 of an exemplary two-dimensional electrode 130 shown in accordance with some embodiments of the present description; fig. 17C is a schematic diagram of the shape of the first-order electrode 130-1 corresponding to a rectangle equivalent to a two-terminal clamped beam according to some embodiments of the present disclosure.

As shown in fig. 17A, the piezoelectric assembly 120 may be divided (divided by 15 dotted lines) into 16 rectangles in the length direction (horizontal direction as in fig. 17A), wherein the 16 rectangles each take the width of the piezoelectric assembly 120 as the length and equally divide the length of the piezoelectric assembly 120; similarly, the piezoelectric element 120 is divided (divided by 7 broken lines) into 8 rectangles in the width direction (vertical direction in fig. 17A). Both the 16 rectangles in the length direction and the 8 rectangles in the width direction can be equivalently two-end clamped beams. As shown in fig. 7, the width of the rectangular clamped beam from one fixed area 124 to the other fixed area 124 gradually increases from 0 and then gradually decreases to 0 in the length direction, forming a "fusiform". In some embodiments, the increase or decrease in width may include one or any combination of a gradient increase or decrease in width, a linear increase or decrease, a curvilinear increase or decrease, and the like. It should be understood that fig. 17C only shows the shape of the electrode in the length direction, and each rectangular clamped beam in the width direction may be similarly shaped. In some embodiments, according to the shape of the first-order electrode 130-1 shown in fig. 17C, a first shape 171 (e.g., 16-column fusiform in fig. 17A) of the plurality of discrete electrode units 134 in the length direction and a second shape 172 (e.g., 8-row fusiform in fig. 17A) of the plurality of discrete electrode units 134 in the width direction are determined, so that the two-dimensional electrode 130 is determined based on the first shape 171 and the second shape 172. As shown in fig. 17B, the two-dimensional electrode 130 may be overlapping regions of the first shape 171 and the second shape 172, each overlapping region may be one discrete electrode unit 134.

Fig. 18 is a diagram of a vibration mode of a piezoelectric assembly 120 covering a two-dimensional electrode 130 shown in fig. 17B, according to some embodiments of the present disclosure.

As shown in fig. 18, the piezoelectric component 120 covered with the two-dimensional electrode 130 shown in fig. 17B still has a mode shape at a high frequency band (e.g., 18326 Hz) close to the first-order mode shape, so that sound pressure can be effectively output, and the sound pressure level amplitude of the vibration output region is significantly improved. In comparison with the two-dimensional electrode shown in fig. 14C (the vibration mode diagram is shown in fig. 16C and 16D), mode control can also be achieved with the two-dimensional electrode 130 shown in fig. 17B.

In some embodiments, discrete electrode units have the problem that the circuit connection between the electrodes is difficult, and the mass production difficulty is high. Therefore, the electrode can be changed from discrete to connected, which is beneficial to the manufacture of printing screen and the connection of the electrode and is suitable for mass production. For example, the electrode 130 may include two-dimensionally distributed continuous electrodes 135, and the continuous electrodes may include a plurality of hollowed-out areas 136 thereon.

In some embodiments, the continuous electrode 135 may be configured as a continuous conductive material disposed on the surface of the piezoelectric assembly 120, and the hollowed-out region 136 may be configured as a region where no conductive material is disposed. Compared to the above-mentioned multiple discrete electrode units 134 shown in fig. 14A-14D or 17B, the continuous electrode 135 can be understood as an electrode 130 formed by integrally connecting discrete electrodes, and the continuous electrode 135 is further discrete into multiple two-dimensional distributed areas by providing multiple hollowed-out areas 136, so as to realize the design of the electrode 130.

FIG. 19A is a schematic view of a portion of a structure of an exemplary two-dimensional distribution of continuous electrodes 130 shown in accordance with some embodiments of the present disclosure;

FIG. 19B is a schematic view of a portion of a structure of an exemplary two-dimensional distribution of continuous electrodes 130 shown in accordance with some embodiments of the present disclosure; fig. 19C is a schematic view of a portion of a structure of an exemplary two-dimensionally distributed continuous electrode 130 according to some embodiments of the present disclosure.

As shown in fig. 19A-19C, the two-dimensional electrode 130 (quarter two-dimensional electrode) may include two-dimensionally distributed continuous electrodes 135, and the continuous electrodes 135 may include a plurality of hollowed-out regions 136.

In some embodiments, the hollowed-out region 136 may or may not have the same shape as the piezoelectric element 120. In some embodiments, the hollowed-out area 136 may include one or any combination of a circle, triangle, quadrilateral, pentagon, hexagon, or irregularity. For example, the continuous electrode 135 as shown in fig. 19A may include a plurality of square hollowed-out areas 136; the continuous electrode 135 as shown in fig. 19B may include a plurality of hexagonal hollowed-out regions 136; the continuous electrode 135 shown in fig. 19C may include a plurality of quadrangular hollowed-out areas and a plurality of octagonal hollowed-out areas.

In some embodiments, the spacing between two adjacent hollowed-out regions 136 at the center of the piezoelectric layer 122 may be greater than the spacing between two adjacent hollowed-out regions 136 at the boundary of the piezoelectric layer. As illustrated in fig. 19A to 19C, the closer to the boundary, the smaller the space between the adjacent two hollowed-out areas 136.

In some embodiments, the area of the first hollowed-out region 1361 at the center of the piezoelectric layer 122 is smaller than the area of the second hollowed-out region 1362 at the boundary of the piezoelectric layer. As shown in fig. 19A-19C, the first hollow region 1361 is closer to the center of the piezoelectric layer 122 than the second hollow region 1362, and the area of the first hollow region 1361 is smaller than the area of the second hollow region 1362.

In some embodiments, the piezoelectric layer 122 may be divided into a plurality of two-dimensionally distributed piezoelectric subregions of the same size, each of which may include one hollowed-out region 136, and the hollowed-out region 136 may be located at the center of the piezoelectric subregion, and the continuous electrodes 135 in the piezoelectric subregion may be located at edges of the piezoelectric subregion, forming continuous connected electrodes with the continuous electrodes 135 of other piezoelectric subregions. For example, as shown in fig. 19A to 19C, the hollowed-out region 136 may be provided at the center of the piezoelectric subregion so that the electrode 130 at the edge of the piezoelectric subregion is continuous.

In some embodiments, the size of the hollowed-out region 136 may be related to the amount of vibration displacement of the piezoelectric region where it is located at a specific frequency (e.g., first-order peak, second-order peak). In some embodiments, the area of the hollowed-out region 136 in each piezoelectric region may be determined based on the difference (e.g., vibration displacement ratio) between the vibration displacement of the piezoelectric region and the maximum displacement of the piezoelectric layer 122 at a particular frequency (e.g., first order peak, second order peak). For example, the larger the difference between the vibration displacement amount and the maximum displacement amount of the piezoelectric layer 122, the larger the area of the hollowed-out region 136. Fig. 20 is a comparative schematic of the frequency response curves of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description.

As shown in fig. 20, curve 26 is a frequency response curve of the piezoelectric element 120 using the whole electrode, curve 26 is a frequency response curve of the piezoelectric element 120 covering the two-dimensional electrodes 130 of 32×32 discrete electrode units, and curve 27 is a frequency response curve of the piezoelectric element 120 covering the two-dimensionally distributed 32×32 continuous electrodes 130. According to the curves 26 and 27, the modal control effect of the two-dimensionally distributed continuous electrode 130 is somewhat different from that of the electrode 130 composed of two-dimensionally distributed discrete electrode units. For example, the electrode 130 composed of two-dimensionally distributed discrete electrode units is shifted forward to 7829.4Hz at the resonance valley at 12128 Hz. The resulting forward shift of the resonant valley may be related to the hollowed-out shape and the crowding of the electrode 130, but still exhibit some modal control effect on the piezoelectric assembly 120.

In the embodiment of the present disclosure, the continuous electrode 135 includes a plurality of hollowed-out areas 136, so that the coverage of the two-dimensional electrode 130 is changed from discrete to connected, which is beneficial to the generation, manufacture and use of the two-dimensional electrode, and is more suitable for mass production.

It should be appreciated that, similar to a one-dimensional electrode, the design of a two-dimensional electrode may also be such that the shape and area of the piezoelectric region in the piezoelectric layer (e.g., piezoelectric plate, piezoelectric film) defines the effective area of the electrode overlying the piezoelectric layer. For example, a piezoelectric plate or film includes a piezoelectric region made of a piezoelectric material and a non-piezoelectric region made of a non-piezoelectric material, the sum of the areas of the piezoelectric region and the non-piezoelectric region being equal to the coverage area of the piezoelectric plate or film on the substrate, and the electrode completely covers the piezoelectric plate or film (i.e., the electrode coincides with the piezoelectric plate or film). The pattern of the piezoelectric region may be a two-dimensional electrode design pattern shown in any of fig. 14A, 14B, 14C, 14D, 17A, 17B, 19A, 19B, or 19C, and the portion of the substrate other than the piezoelectric region is a non-piezoelectric region. Thus, in a two-dimensional electrode design, modal control of the piezoelectric assembly may be achieved by the piezoelectric region area < the coverage area of the piezoelectric layer (e.g., piezoelectric plate, piezoelectric film) =the coverage area of the electrode +..

In some embodiments, the electrode 130 may be coated on one surface of the piezoelectric layer 122, or on both surfaces of the piezoelectric layer. For example, the electrode 130 may also be covered on the other surface opposite to the above surface, and the covered area of the electrode 130 on the other surface may be equal to or smaller than the area of the surface. That is, the design of the electrodes 130 may be implemented on two opposite surfaces to control the mode of the piezoelectric assembly 120. The design of the electrode 130 on the other surface may be referred to as any of the electrode 130 designs described above with reference to fig. 5A, 5C, 8A-8D, 11A, 11B, 14A-14D, 17B, 19A-19C, and will not be repeated here.

In some embodiments, the piezoelectric assembly 120 may also include a vibration modulating assembly. Wherein the vibration regulating assembly may be configured as a device that changes the vibration state of the acoustic device (e.g., adjusts the vibration mode of the output by changing the mass, elasticity, or damping of one or more components within the acoustic device). In some embodiments, the vibration modulating assembly may be coupled to the vibration output region 123 of the piezoelectric assembly 120 and adjust the vibration output by the piezoelectric assembly 120. In some embodiments, the vibration modulating assembly may include one or any combination of a connector (e.g., a housing, etc.), a mass (e.g., a metallic mass, etc.), a spring (e.g., a pull-cord, a spring plate, etc.). The connecting piece may connect the piezoelectric component 120 with other components, and the elastic piece may provide elastic force for the piezoelectric component 120, so as to change the vibration state of the piezoelectric component 120.

In some embodiments, the vibration modulating assembly may include a mass 170 that is physically (e.g., mechanically or electromagnetically) connected to the vibration output region 123. In some embodiments, the mass 170 may be an assembly having a certain mass. In some embodiments, the mass 170 may comprise one or any combination of metallic masses, rubber masses, plastic masses, and the like. In some embodiments, the mass 170 may be used to change the mode of the piezoelectric assembly 120.

In some embodiments, the acoustic device 100 further includes a connector 171, the connector 171 connecting the vibration assembly 110 and the piezoelectric assembly 120. In some embodiments, the connector may be configured as a rigid assembly and the connector 171 may include one or any combination of vibration-transmitting sheets, elastic members, and the like. In some embodiments, the mass 170 may be connected to the vibration output region 132 by a connection 171.

An exemplary acoustic device is provided below, taking the piezoelectric assembly 120 shown in fig. 3 described above as an example, and the specific implementation of the piezoelectric cantilever, mass 170, and connector 171 is described in detail.

Fig. 21 is a schematic structural diagram of an exemplary acoustic device according to some embodiments of the present description. In some embodiments, the acoustic device may include at least one piezoelectric assembly 120, and the vibration output region of each piezoelectric assembly 120 may be coupled to one vibration assembly 110, with each vibration assembly 110 coupled to a vibration modulating assembly (e.g., mass 170). As shown in fig. 21, the acoustic device may include two piezoelectric assemblies 120 covered with first-order electrodes 130-1, the vibration output region of each piezoelectric assembly 120 being connected to a vibration assembly 110, the vibration assembly 110 being connected to a vibration modulating assembly (e.g., a mass 170) through at least one connection 171.

In some embodiments, the length of the piezoelectric assembly 120 in the acoustic device may be shortened to reduce the mode of the piezoelectric assembly 120. For example, the acoustic device may utilize the elasticity provided by the connection 171 and the mass 170 to construct a low frequency peak, thereby employing a short piezoelectric cantilever (piezoelectric assembly 120 as shown in fig. 21) to reduce the modal form a flat frequency response curve between the low frequency peak and the first order modal peak (higher frequency) of the frequency response curve.

Fig. 22 is a comparative schematic of the frequency response curves of an exemplary piezoelectric assembly shown in accordance with some embodiments of the present description.

As shown in fig. 22, curve 29 is a frequency response curve of the piezoelectric assembly 120 using the monolithic electrode having a length of 8mm, and curve 30 is a frequency response curve of the piezoelectric assembly 120 using the first-order electrode 130-1 having a length of 8 mm; curve 31 is a frequency response curve of the piezoelectric assembly 120 using the first-order electrode 130-1 having a length of 10 mm; curve 32 is a plot of the frequency response of piezoelectric assembly 120 using first-order electrode 130-1 having a length of 12 mm.

As shown in fig. 22, the corresponding frequency response curve of the piezoelectric assembly 120 shown by the curve 29 generates a second-order resonance at a second-order modal valley (e.g., 12272 Hz), which may reflect that the piezoelectric assembly 120 employing the integral electrode in the acoustic device cannot effectively output vibration, resulting in a resonance valley on the frequency response curve. The resonant valley of the frequency response curve corresponding to the piezoelectric component 120 shown in the curve 30-32 is raised, and the vibration characteristic of the resonant valley is not affected, so that the design of the first-order electrode 130-1 in the acoustic device can be reflected, and the second-order resonant valley generated by the piezoelectric component 120 can be raised.

In addition, the mode forward movement of the piezoelectric cantilever beam (i.e., the piezoelectric component 120) and the vibration transmitting sheet in the frequency response curve corresponding to the piezoelectric component 120 shown in the curve 30-32 may reflect that when the design of the first-order electrode 130-1 is adopted in the acoustic device, the length of the piezoelectric component 120 is appropriately prolonged (for example, the length of the piezoelectric component 120 is set to be not less than 8mm, not less than 10mm, or not less than 12 mm), and the sensitivity of low frequency in the acoustic device may be improved while the resonance valley is improved.

FIG. 23A is a vibration mode diagram of an acoustic device employing integral electrode 130, shown in accordance with some embodiments of the present description; fig. 23B is a vibration mode diagram of an acoustic device employing a first-order electrode 130-1, according to some embodiments of the present description.

As shown in fig. 23A, at the resonance valley (e.g., 12272 Hz), the vibration output region of the piezoelectric assembly 120 in an acoustic device employing an integral electrode forms a node. As shown in fig. 23B, at the resonance valley (e.g., 12272 Hz), the vibration output region of the piezoelectric element 120 in the acoustic device employing the first-order electrode 130-1 is not formed as a node, and is of the first-order vibration type.

In the embodiment provided in the present disclosure, the electrode 130 may be designed to raise the second-order resonance valley generated by the corresponding frequency response curve of the piezoelectric component 120 in the acoustic device, and may employ a longer piezoelectric component 120 to raise the sensitivity of low frequencies in the acoustic device.

In some embodiments, as shown in fig. 24, the acoustic device 100 may be in a piezoelectric cantilever output configuration, with a piezoelectric cantilever arm (i.e., piezoelectric assembly 120) of electrode design having a fixed region 124 at one end and a vibration output region 123 at the other end, and outputting vibrations to a vibrating plate or diaphragm (i.e., vibration assembly 110) via a connection 171. In some embodiments, the acoustic device 100 may be a bone conduction audio device (e.g., bone conduction headphones, bone conduction glasses, etc.). In some embodiments, the fixed end of the piezoelectric assembly 120 may include one or any number of sets of a housing of the bone conduction audio apparatus, an ear-hook apex, an ear-hook-to-board bin connection, glasses legs, and the like. In some embodiments, the connection member 171 may have a certain rigidity and be rigidly connected to the vibration plate or the diaphragm, the vibration output area of the piezoelectric cantilever arm.

Possible benefits of embodiments of the present description include, but are not limited to: (1) The mode actuator of the piezoelectric component is formed through electrode design, so that the piezoelectric component only generates exciting force of a specific mode to output a specific mode shape, the node formed by vibration output points of the piezoelectric component is avoided, and the working reliability of the acoustic equipment is improved. (2) Compared with a mode control system formed by adding mechanical structures such as springs, masses, damping and the like to a specific area, the mode control of the piezoelectric component can be realized based on electrode design, and the structure of the acoustic device is simplified.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements, and adaptations to the present disclosure may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within this specification, and therefore, such modifications, improvements, and modifications are intended to be included within the spirit and scope of the exemplary embodiments of the present invention.

Meanwhile, the specification uses specific words to describe the embodiments of the specification. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the present description. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the present description may be combined as suitable.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations in the description are not intended to limit the order in which the processes and methods of the description are performed unless explicitly recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of various examples, it is to be understood that such details are merely illustrative and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements included within the spirit and scope of the embodiments of the present disclosure. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Likewise, it should be noted that in order to simplify the presentation disclosed in this specification and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure, however, is not intended to imply that more features than are presented in the claims are required for the present description. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations that may be employed in some embodiments to confirm the breadth of the range, in particular embodiments, the setting of such numerical values is as precise as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., referred to in this specification is incorporated herein by reference in its entirety. Except for application history documents that are inconsistent or conflicting with the content of this specification, documents that are currently or later attached to this specification in which the broadest scope of the claims to this specification is limited are also. It is noted that, if the description, definition, and/or use of a term in an attached material in this specification does not conform to or conflict with what is described in this specification, the description, definition, and/or use of the term in this specification controls.

Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments of this specification. Other variations are possible within the scope of this description. Thus, by way of example, and not limitation, alternative configurations of embodiments of the present specification may be considered as consistent with the teachings of the present specification. Accordingly, the embodiments of the present specification are not limited to only the embodiments explicitly described and depicted in the present specification.

Claims

1. An acoustic device, comprising:

The piezoelectric assembly generates vibration under the action of the driving voltage;

an electrode that provides the driving voltage for the piezoelectric assembly; and

a vibration assembly physically connected to the piezoelectric assembly, receiving the vibrations and producing sound; wherein the piezoelectric assembly comprises:

a substrate; and

a piezoelectric layer covering one surface of the substrate, the piezoelectric layer including a piezoelectric region and a non-piezoelectric region, wherein,

the electrode covers one surface of the piezoelectric layer,

the substrate, the piezoelectric layer and the electrode are respectively overlapped;

the coverage area of the piezoelectric region on the substrate is smaller than that of the piezoelectric layer on the substrate.

2. The acoustic device of claim 1, wherein the piezoelectric assembly comprises a vibration output region.

3. The acoustic device of claim 2, wherein the piezoelectric assembly further comprises a fixed region.

4. An acoustic device according to claim 3, wherein the width of the piezoelectric region decreases gradually from the fixed region to the vibration output region.

5. An acoustic device according to claim 3, wherein the piezoelectric region comprises two piezoelectric envelope regions, the two electrode regions corresponding to the two piezoelectric envelope regions being opposite in potential.

6. An acoustic device according to claim 3, wherein the width of the piezoelectric region at the fixed region is equal to the width of the fixed region.

7. An acoustic device according to claim 3, wherein the width of the piezoelectric region at the vibration output region is 0.

8. The acoustic device of claim 1, wherein the piezoelectric layer comprises a piezoelectric plate or a piezoelectric film.

9. The acoustic device of claim 8, wherein the electrode comprises a plurality of discrete electrode units distributed in two dimensions.

10. The acoustic device of claim 9, wherein a gap between adjacent two discrete electrode units at a center of the piezoelectric layer is smaller than a gap between adjacent two discrete electrode units at a boundary of the piezoelectric layer among the plurality of discrete electrode units.

11. The acoustic device of claim 9, wherein an area of a first discrete electrode unit at a center of the piezoelectric layer is greater than an area of a second discrete electrode unit at a boundary of the piezoelectric layer.

12. The acoustic device of claim 8 wherein the electrode comprises a two-dimensionally distributed continuous electrode comprising a plurality of hollowed-out areas thereon.

13. The acoustic device of claim 12, wherein an area of a first hollowed-out region at a center of the piezoelectric layer is smaller than an area of a second hollowed-out region at a boundary of the piezoelectric layer.