Acoustic devices

Abstract

To provide acoustic devices capable of controlling vibration modes of a piezoelectric component.SOLUTION: An acoustic device is disclosed. The device comprises a piezoelectric component, an electrode, and a vibration component. The piezoelectric component generates vibration under an action of a driving voltage, the electrode provides the driving voltage for the piezoelectric component, and the vibration component is physically connected to the piezoelectric component to receive the vibration and generate sound. The piezoelectric component includes a substrate and a piezoelectric layer, where the piezoelectric layer covers a surface of the substrate, the electrode covers a surface of the piezoelectric layer, and coverage area of the electrode on the surface of the piezoelectric layer is less than area of the surface of the substrate covered with the piezoelectric layer. In the present disclosure, the electrode is designed for a modal actuator of the piezoelectric component and the piezoelectric component outputs a vibration form of a specific mode and improves sound characteristics of the acoustic device. Compared with adding a modal control system consisting of different mechanical structures in a specific region, the embodiment of this present disclosure can realize modal control of the piezoelectric component through the electrode design, and simplify the structure of the acoustic device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This specification relates to the technical field of acoustics, and more particularly to acoustic devices.

Background Art

[0002] An acoustic device can transmit sound by deforming a piezoelectric component by applying electrical energy to the piezoelectric component. For example, the acoustic device applies a driving voltage to the piezoelectric component in its polarization direction, generates vibrations by the inverse piezoelectric effect of the piezoelectric material, and outputs vibrations from the vibration output point of the piezoelectric component, thereby emitting sound waves to the outside.

[0003] However, the piezoelectric component of the acoustic device has many vibration modes within the audible frequency range and cannot form a flat frequency response curve.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, it is necessary to provide an acoustic device capable of controlling the vibration modes of the piezoelectric component.

Means for Solving the Problems

[0005] One embodiment of this specification provides an acoustic device. The device includes a piezoelectric component, an electrode, and a vibration component. The piezoelectric component vibrates under the action of a driving voltage, the electrode supplies the driving voltage to the piezoelectric component, and the vibration component is physically connected to the piezoelectric component, receives vibrations, and generates sound. The piezoelectric component may include a substrate and a piezoelectric layer, the piezoelectric layer covers one surface of the substrate, the electrode covers one surface of the piezoelectric layer, and the covered area of the electrode on the surface of the piezoelectric layer is smaller than the area of the surface of the substrate covered by the piezoelectric layer.

[0006] In some embodiments, the piezoelectric component includes a vibration output region.

[0007] In some embodiments, the piezoelectric component further includes a fixed region.

[0008] In some embodiments, the piezoelectric component further includes a vibration adjusting component.

[0009] In some embodiments, the width of the electrode gradually decreases from the fixed region to the vibration output region.

[0010] In some embodiments, the electrode includes two electrode envelope regions with opposite potentials.

[0011] In some embodiments, there is a conversion point between the two electrode envelope regions, and the width of the electrode in the first electrode envelope region of the two electrode envelope regions gradually decreases from the fixed region to the conversion point.

[0012] In some embodiments, the width of the electrode in the second electrode envelope region of the two electrode envelope regions increases first and then decreases from the conversion point to the vibration output region.

[0013] In some embodiments, the width of the electrode in the fixed region is equal to the width of the fixed region.

[0014] In some embodiments, the width of the electrode in the vibration output region is zero.

[0015] In some embodiments, the piezoelectric layer overlaps with the substrate.

[0016] In some embodiments, the piezoelectric layer includes a piezoelectric region and a non-piezoelectric region.

[0017] In some embodiments, the piezoelectric region overlaps with the electrode.

[0018] In some embodiments, the piezoelectric layer overlaps with the electrode.

[0019] In some embodiments, the piezoelectric layer includes a piezoelectric plate or a piezoelectric film.

[0020] In some embodiments, the electrode includes a plurality of distributed electrode units that are two-dimensionally distributed.

[0021] In some embodiments, in the plurality of distributed electrode units, the gap between two adjacent distributed electrode units at the center of the piezoelectric layer is smaller than the gap between two adjacent distributed electrode units at the boundary of the piezoelectric layer.

[0022] In some embodiments, the area of the first distributed electrode unit at the center of the piezoelectric layer is larger than the area of the second distributed electrode unit at the boundary of the piezoelectric layer.

[0023] In some embodiments, the electrode includes a continuous electrode that is two-dimensionally distributed, and the continuous electrode includes a plurality of embossed regions.

[0024] In some embodiments, the area of the first embossed region at the center of the piezoelectric layer is smaller than the area of the second embossed region at the boundary of the piezoelectric layer.

[0025] In some embodiments, the electrode covers the other surface opposite to the surface, and the covered area of the electrode on the other surface is less than or equal to the area of the surface.

[0026] In some embodiments, the vibration adjustment component includes a mass block, and the mass block is physically connected to the vibration output region.

[0027] In some embodiments, the acoustic device further includes a connecting member that connects the vibration component and the piezoelectric component.

[0028] In some embodiments, the acoustic device is a bone conduction audio device.

[0029] One embodiment of this specification provides an acoustic device. The device includes a piezoelectric component, an electrode, and a vibration component. The piezoelectric component vibrates under the action of a driving voltage, the electrode supplies the driving voltage to the piezoelectric component, and the vibration component is physically connected to the piezoelectric component to receive vibration and generate sound. The piezoelectric component may include a substrate and a piezoelectric layer covering one surface of the substrate and including a piezoelectric region and a non-piezoelectric region. The electrode covers one surface of the piezoelectric layer, and the substrate, the piezoelectric layer, and the electrode overlap each other. The covered area of the piezoelectric region on the substrate is smaller than the covered area of the piezoelectric layer on the substrate.

[0030] In some embodiments, the piezoelectric component includes a vibration output region.

[0031] In some embodiments, the piezoelectric component further includes a fixed region.

[0032] In some embodiments, the width of the piezoelectric region gradually decreases from the fixed region to the vibration output region.

[0033] In some embodiments, the piezoelectric region includes two piezoelectric envelope regions, and the potentials of the two electrode regions corresponding to the two piezoelectric envelope regions are opposite.

[0034] In some embodiments, the width of the piezoelectric region in the fixed region is equal to the width of the fixed region.

[0035] In some embodiments, the width of the piezoelectric region in the vibration output region is zero.

Advantages of the Invention

[0036] In the embodiments of this specification, by designing the electrode as a mode actuator of the piezoelectric component, the piezoelectric component can generate only the excitation force of a specific mode and output the vibration form of the specific mode, thereby improving the sound characteristics of the acoustic device.

[0037] Compared with adding a mode control system composed of different mechanical structures such as springs, masses, and damping elements to a specific area, the embodiments in this specification can realize the mode control of piezoelectric components through the design of electrodes, and simplify the structure of the acoustic device.

[0038] The present specification will be further described by exemplary embodiments, and these exemplary embodiments will be described in detail with reference to the drawings. These embodiments are not limiting, and in these embodiments, the same numbers indicate the same structures.

Brief Description of the Drawings

[0039]

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Embodiments for Carrying Out the Invention

[0040] To more clearly explain the technical means of the embodiments of this specification, the drawings necessary for the description of the embodiments will be briefly explained below. Obviously, the drawings described below are only some examples or embodiments of this specification, and those skilled in the art can apply this specification to other similar scenarios based on these drawings without requiring creative effort. Unless it is obvious from the language environment or otherwise stated, the same numbers in the figures indicate the same structure or operation.

[0041] It should be understood that the terms "system", "device", "unit" and / or "module" used in this specification are a way to distinguish various assemblies, elements, components, parts or assemblies at different levels. However, other expressions can be used instead of the above terms if other terms can achieve the same purpose.

[0042] As used in this specification and the claims, unless the context clearly indicates otherwise, terms such as "one", "a", "a kind" and / or "the" do not particularly mean the singular form and may include the plural form. Generally, the terms "comprising" and "containing" merely present that they include the specifically specified steps and elements, and these steps and elements are not an exclusive listing, and the method or device may also include other steps or elements.

[0043] In this specification, a flowchart is used to describe the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding and subsequent operations are not necessarily executed exactly in accordance with the order. Instead, each step may be processed in the reverse order or simultaneously. Also, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0044] The acoustic device of one or more embodiments of this specification outputs sound by vibrating piezoelectric components, and thus is applicable to various scenarios where audio needs to be played. For example, the acoustic device may be an independent audio output device (such as a sound box, earphone, etc.) that can play audio based on user instructions. Also, the acoustic device may be a module or component in a terminal device (such as a mobile phone, computer, etc.) that can play audio based on terminal instructions. In some embodiments, the acoustic device adjusts the deformation of the piezoelectric components based on parameters such as the frequency and magnitude of the sound to be output, so as to generate different vibrations. Accordingly, the vibrating component can output different sounds according to different vibrations.

[0045] In some embodiments, the acoustic device may be a bone conduction acoustic device. The vibrating component in the bone conduction acoustic device fits the user's body tissue, and the sound waves emitted by the vibrating component can be transmitted to the user's inner ear by the user's bone. In some embodiments, the acoustic device may be other types of acoustic devices such as an air conduction acoustic device, a hearing aid, a cochlear implant, glasses, a helmet, an Augmented Reality (AR) device, a Virtual Reality (VR) device, etc. Alternatively, the acoustic device may be used to output sound as part of an in-vehicle audio system or an indoor audio system.

[0046] At present, the piezoelectric component of the audio device has many vibration modes within the audible frequency range and cannot form a flat frequency response curve. In addition, nodes may be formed in the vibration output region at some frequencies in the piezoelectric component, which may affect the effect of the audio output.

[0047] In the embodiments of this specification, an audio device is described. The above audio device may include a piezoelectric component, an electrode, and a vibration component. The piezoelectric component vibrates under the action of a driving voltage. The electrode supplies the driving voltage to the piezoelectric component. The vibration component is physically connected to the piezoelectric component, receives the vibration, and generates sound. The above piezoelectric component may include a substrate and a piezoelectric layer. In some embodiments, the piezoelectric layer covers one surface of the substrate, the electrode covers one surface of the piezoelectric layer, and the covered area of the electrode on the surface of the piezoelectric layer is smaller than the area of the surface of the substrate covered by the piezoelectric layer. In some embodiments, the piezoelectric layer covers one surface of the substrate, the electrode covers one surface of the above piezoelectric layer, and the above substrate, the above piezoelectric layer, and the above electrode overlap each other. The piezoelectric layer includes a piezoelectric region and a non-piezoelectric region, and the covered area of the piezoelectric region on the substrate is smaller than the covered area of the piezoelectric layer on the substrate.

[0048] In the embodiments of this specification, by designing the electrode as a mode actuator of the piezoelectric component, the piezoelectric component can generate only the excitation force of a specific mode and output the vibration form of the specific mode, thereby improving the audio characteristics of the audio device.

[0049] And compared with adding a mode control system composed of mechanical structures such as springs, masses, and damping elements to a specific region, the embodiments of this specification can realize the mode control of the piezoelectric component through the design of the electrode and simplify the structure of the audio device.

[0050] FIG. 1 is a block diagram of an exemplary acoustic device 100 according to some embodiments of the present specification. In some embodiments, as shown in FIG. 1, the acoustic device 100 may include a vibration component 110, a piezoelectric component 120, and an electrode 130. The piezoelectric component 120 vibrates under the action of a driving voltage, the electrode 130 supplies the driving voltage to the piezoelectric component 120, and the vibration component 110 is physically (e.g., mechanically or electromagnetically) connected to the piezoelectric component 120 to receive vibration and generate sound.

[0051] The vibration component 110 may be configured as a component that transmits vibration and generates sound. In some embodiments, the vibration component 110 may include an elastic element, and the elastic element deforms in response to vibration and changes the sound pressure around itself to generate sound waves and realize the output of sound. In some embodiments, the elastic element may include a vibration transmission sheet, rubber, a dome, etc., or any combination thereof. In some embodiments, the material of the elastic element may be any material having vibration transmission ability. 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 membrane structure (e.g., an air conduction vibration membrane), a plate structure (e.g., a bone conduction vibration panel, etc.), or other structures such as a mesh structure or a layered structure.

[0052] Hereinafter, an exemplary acoustic device 100 is provided to describe specific implementation manners of the vibration component 110.

[0053] FIG. 2 is a schematic configuration diagram of an exemplary acoustic device 100 according to some embodiments of the present specification. As shown in FIG. 2, one end of the vibration component 110 may be connected to the vibration output region 123 of the piezoelectric component 120 to receive vibration. The other end of the vibration component 110 can output sound. Exemplarily, the vibration component 110 transmits sound waves to the user through one or more media (e.g., air, the user's bone, etc.) so that the user can hear the sound output from the acoustic device 100.

[0054] The piezoelectric component 120 may be configured as an electric energy conversion device that converts electric energy into mechanical energy. In some embodiments, the piezoelectric component 120 can vibrate by deforming under the action of a driving voltage. In some embodiments, the piezoelectric component 120 may have a shape such as sheet-like, annular, rhombic, cuboid, cylindrical, spherical, or any combination thereof, or other irregular shapes. In some embodiments, the piezoelectric component 120 may include a substrate 121 and a piezoelectric layer 122.

[0055] The substrate 121 may be configured as a carrier for mounting elements and devices, and an element that deforms in response to vibration. In some embodiments, the material of the substrate 121 may include one or more combinations of metals (e.g., copper-clad foil, steel, etc.), phenolic resin, cross-linked polystyrene, etc. In some embodiments, the shape of the substrate 121 may be determined based on the shape of the piezoelectric component 120. For example, if the piezoelectric component 120 is a piezoelectric beam, the substrate 121 may be made long accordingly. Also, for example, if the piezoelectric component 120 is a piezoelectric film, the substrate 121 may be made plate-like or sheet-like accordingly.

[0056] The piezoelectric layer 122 may be configured as a component that generates a piezoelectric effect and / or an inverse piezoelectric effect. In some embodiments, the piezoelectric layer 122 covers one or more surfaces of the substrate 121 and can realize the vibration output of the piezoelectric component 120 by deforming under the action of a driving voltage to deform the substrate 121. In some embodiments, the piezoelectric layer 122 may all be piezoelectric regions, that is, the piezoelectric layer 122 may be made of a piezoelectric material. In some embodiments, the piezoelectric layer 122 may include piezoelectric regions and non-piezoelectric regions. The piezoelectric regions and the non-piezoelectric regions are connected to form the piezoelectric layer 122. In some embodiments, the piezoelectric regions are made of a piezoelectric material, and the non-piezoelectric regions are made of a non-piezoelectric material. In some embodiments, the piezoelectric material may include piezoelectric crystals, piezoelectric ceramics, piezoelectric polymers, etc., or any combination thereof. In some embodiments, the piezoelectric crystals may include quartz, zinc blende, wurtzite, tourmaline, zincite, GaAs, barium titanate and its derivative crystals, KH2PO4, NaKC4H4O6·4H2O (Rochelle salt), etc., or any combination thereof. In some embodiments, the piezoelectric ceramic is a piezoelectric polycrystal in which fine crystal grains obtained by a solid-phase reaction and sintering between powders of different materials are randomly aggregated. In some embodiments, the piezoelectric ceramic material may include barium titanate (BT), lead zirconate titanate (PZT), barium lithium niobate (PBLN), modified lead titanate (PT), aluminum nitride (AIN), zinc oxide (ZnO), etc., or any combination thereof. In some embodiments, the piezoelectric polymer material may include polyvinylidene fluoride (PVDF). In some embodiments, the non-piezoelectric material may include ceramics and rubber. In some embodiments, the mechanical properties of the non-piezoelectric material may be similar to those of the piezoelectric material. In some embodiments, for the specific implementation manners of the piezoelectric regions and the non-piezoelectric regions, reference may be made to the relevant content shown in FIG. 8A or 8D below, so the description is omitted here.

[0057] The electrode 130 may be configured as an element that supplies a driving voltage to the piezoelectric component 120. In some embodiments, the electrode 130 may be a combination of one or more of a metal electrode (e.g., a copper electrode, a silver electrode, etc.), a redox electrode (e.g., a Pt|Fe and Fe electrode, a Pt|Mn MnO electrode), an insoluble salt electrode (e.g., a calomel electrode, a mercury oxide electrode), etc. In some embodiments, the electrode 130 may be provided on at least one surface of the piezoelectric layer 122, for example, on two opposing surfaces of the piezoelectric layer 122. In some embodiments, the electrode may be provided on the surface of the piezoelectric layer 122 by one or more bonding methods such as coating, embedding, laminating, etc.

[0058] In some embodiments, the piezoelectric layer 122 may cover at least one surface of the substrate 121. In some embodiments, the electrode 130 may cover at least one surface of the piezoelectric layer 122. To illustrate the arrangement between the substrate 121, the piezoelectric layer 122, and the electrode 130, FIGS. 3 and 4 provide two exemplary acoustic devices 100.

[0059] FIG. 3 is a schematic configuration diagram of an exemplary piezoelectric component 120 according to some embodiments of the present specification. As shown in FIG. 3, the piezoelectric component 120 may be a piezoelectric cantilever beam. The substrate 121 can place the piezoelectric layer 122 and the electrode 130 (shown in the similar triangular region). In some embodiments, the electrode 130 may be provided on one or more surfaces of the piezoelectric layer 122 to supply a driving voltage to the piezoelectric layer 122. In some embodiments, the piezoelectric layer 122 may cover one or more surfaces of the substrate 121. When the piezoelectric layer 122 deforms under the action of a driving voltage, the substrate 121 deforms accordingly, so that the vibration output region of the piezoelectric component 120 outputs vibration. For example, the piezoelectric layer 122 may cover only one surface of the substrate 121. Also, for example, as shown in FIG. 3, two piezoelectric layers 122 may cover two opposite surfaces of the substrate 121 respectively.

[0060] FIG. 4 is a schematic configuration diagram of a part of an exemplary piezoelectric component 120 according to some embodiments of the present specification. As shown in FIG. 4, the piezoelectric component 120 may be a piezoelectric plate (or a piezoelectric film). The substrate 121 can place the piezoelectric layer 122 and the electrodes 130 (shown as a plurality of squares distributed two-dimensionally). In some embodiments, the area of the piezoelectric layer 122 may be larger than that of the substrate 121 or smaller than that of the substrate 121. In some embodiments, the electrodes 130 may be provided on one or more surfaces of the piezoelectric plate to supply a driving voltage to the piezoelectric plate. In some embodiments, the piezoelectric layer 122 may cover one or more surfaces of the substrate 121. When the piezoelectric layer 122 deforms under the action of a driving voltage, the substrate 121 deforms accordingly, so that the vibration output region 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. Also for example, two piezoelectric layers 122 may cover two corresponding surfaces of the substrate 121 respectively.

[0061] In some embodiments, the piezoelectric component 120 may include a vibration output region 123 that transmits the vibration generated by the piezoelectric component 120 to the vibration component 110. In some embodiments, the vibration output region 123 may be one surface, one side, one point, etc. of the piezoelectric component 120, or any combination thereof. As shown in FIG. 3, when the piezoelectric component 120 is a piezoelectric cantilever beam, one side or a partial region of the surface of the piezoelectric component 120 may be the vibration output region 123. As shown in FIG. 4, when the piezoelectric component 120 is a piezoelectric plate or a piezoelectric film, an internal region (for example, a central region of the vibration plane) of the piezoelectric component 120 may be the vibration output region 123.

[0062] In some embodiments, the piezoelectric component 120 may further include a fixed region 124. The fixed region 124 fixes a part of the piezoelectric component 120 and suppresses the vibration of the piezoelectric component 120 in this region, so that most of the vibration of the piezoelectric component 120 is 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 component 120 is a piezoelectric cantilever beam, one end along the long axis direction of the piezoelectric component 120 may be the vibration output region 123, and the other end along the long axis direction corresponding to the vibration output region 123 may be the fixed region 124. Also, for example, when the piezoelectric component 120 is a piezoelectric plate or a piezoelectric film, the vibration output region 123 may be an internal region of the piezoelectric component 120, and the boundary region of the piezoelectric component 120 may be the fixed region 124.

[0063] In some embodiments, in order to reduce the process flow and cost and easily move the piezoelectric component 120, even if the fixed region 124 is not provided in the piezoelectric component 120, the vibration can be transmitted by the vibration output region 123.

[0064] In some embodiments, the vibration of the piezoelectric component 120 has one or more vibration modes. The vibration mode is the natural vibration characteristic of the structural system. When the shape of the electrode is not designed, since the piezoelectric component 120 has many vibration modes, the frequency response curve is not stable. In serious cases, nodes are formed in the vibration output region of the piezoelectric component 120 at some frequencies, which affects the effect of the acoustic output.

[0065] In some embodiments, by designing the shape of the electrode 130 such that the electrode 130 forms a piezoelectric mode actuator and outputs an excitation force, the piezoelectric component 120 generates only a specific mode. In some embodiments, the design of the electrode can be realized by making the covered area of the electrode 130 on the surface of the piezoelectric layer 122 smaller than the area of the surface of the substrate 121 covered by the piezoelectric layer 122. For example, as shown in FIG. 3, the area of the electrode 130 (shown in the similar triangular region) may be smaller than the area of the piezoelectric layer 122, and also smaller than the area of the substrate 121, and the piezoelectric layer 122 may overlap with the substrate 121 (that is, the covered area of the piezoelectric layer 122 on the substrate 121 is the total surface area of one surface of the substrate 121). Also for example, as shown in FIG. 4, the area of the electrode 130 (shown as a plurality of squares distributed two-dimensionally) may be smaller than the area of the piezoelectric layer 122, and also smaller than the area of the substrate 121, and the piezoelectric layer 122 may overlap with the substrate 121 (that is, the covered area of the piezoelectric layer 122 on the substrate 121 is the total surface area of one surface of the substrate 121).

[0066] In some embodiments, mode control can be performed on the piezoelectric component 120 by determining the contour curve of the electrode 130 based on the vibration mode function of the vibration structure of the piezoelectric component 120. In some embodiments, the vibration mode function of the piezoelectric component 120 may include a primary vibration mode and a secondary vibration mode, etc. Correspondingly, the electrode 130 may include a primary electrode 130-1 corresponding to the primary vibration mode, a secondary electrode 130-2 corresponding to the secondary vibration mode, etc.

[0067] Hereinafter, taking the piezoelectric cantilever beam shown in FIG. 3 as an example, two exemplary primary electrodes 130-1 and secondary electrodes 130-2 are provided respectively to describe in detail the specific implementation manner of the electrode design.

[0068] FIG. 5A is a schematic configuration diagram of an exemplary primary electrode 130-1 according to some embodiments of the present specification. FIG. 5B is a schematic diagram of the slope of the curve of the outer contour line of a part of the exemplary primary electrode 130-1 according to some embodiments of the present specification.

[0069] In some embodiments, the width of the electrode 130 may gradually decrease from the fixed region 124 to the vibration output region 123. Here, the "width of the electrode 130" refers to the size of the electrode in the width direction of the piezoelectric component 120 (for example, the width direction of the piezoelectric cantilever beam). The width of the electrode 130 at a certain position (d1, d2 shown in FIG. 5A) may be the distance between two intersections of a line perpendicular to the central axis along the longitudinal direction of the piezoelectric component 120 at that position and the outer contour line of the electrode 130. In some embodiments, the width of the electrode 130 gradually decreasing from the fixed region 124 to the vibration output region 123 may include one or any combination of the width decreasing stepwise, linearly, or curvilinearly, etc. As shown in FIG. 5A, the width of the primary 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 along the outer contour line of the portion above the central axis of the primary electrode 130-1 gradually decreases with the increase in length from the vibration fixing region 124 and becomes zero by the vibration output region 123. In some embodiments, the electrode 130 may be provided symmetrically. For example, the electrode 130 may be symmetric along the central axis of the piezoelectric component 120. In some embodiments, the electrode 130 may be provided asymmetrically. In some embodiments, the shape curve (i.e., the outer contour line) of the electrode 130 may be one or any combination (e.g., linear combination) of trigonometric functions (such as sine function, cosine function, etc.), hyperbolic functions (such as hyperbolic sine function, hyperbolic cosine function, etc.).

[0070] FIG. 5C is a schematic configuration diagram of an exemplary secondary electrode 130-2 according to some embodiments of the present specification. FIG. 5D is a schematic diagram of the slope of the curve of the outer contour line of a part of the exemplary secondary electrode 130-2 according to some embodiments of the present specification.

[0071] In some embodiments, electrode 130 may include two electrode envelope regions with opposite potentials. The electrode envelope region may be the region where the conductive medium of electrode 130 is located, and the potential of the electrode envelope region may be the voltage across both ends of the electrode envelope region. For example, as shown in FIG. 5C, the voltage across both ends of the first electrode envelope region 131 of the secondary electrode 130-2 may be positive, and the voltage across both ends of the second electrode envelope region 132 may be negative. Preferably, the voltage across both ends of the first electrode envelope region 131 may be negative, and the voltage across both ends of the second electrode envelope region 132 may be positive.

[0072] In some preferred embodiments, when the polarization directions of the two electrode envelope regions are the same, it is possible to control the application of opposite-direction potentials to the two electrode envelope regions so that the potentials of the two electrode envelope regions are opposite. In some preferred embodiments, when the polarization directions of the two electrode envelope regions are opposite, it is possible to control the application of the same-direction potentials to the two electrode envelope regions so that the potentials of the two electrode envelope regions are opposite.

[0073] In some embodiments, a conversion point 133 may exist between the two electrode envelope regions, and the width of the electrode in the first electrode envelope region 131 of the two electrode envelope regions may gradually decrease from the fixed region 124 to the conversion point 133.

[0074] In some embodiments, the conversion point 133 may be a point where the potential between the electrode envelope regions is zero, and the potential directions of the regions on both sides of this point (i.e., the two electrode envelope regions) are opposite. In some embodiments, the conversion point 133 can distinguish the electrode envelope regions. For example, the electrode envelope region between the fixed region 124 and the conversion point 133 may be the first electrode envelope region 131. The width of the electrode (d3 shown in FIG. 5C) in the first electrode envelope region 131 at a certain position may be the distance between two intersection points of a line perpendicular to the central axis along the longitudinal direction of the piezoelectric component 120 and the outer contour line of the electrode 130 at this position. In some embodiments, the decrease in the width of the electrode in the first electrode envelope region 131 may include one or any combination of the following, such as decreasing stepwise, linearly, or curvilinearly.

[0075] For example, as shown in FIG. 5C, when the electrode 130 is the secondary electrode 130-2, the potential of the conversion point 133 may be zero, and the potentials of the first electrode envelope region 131 and the second electrode envelope region 132 are opposite. And the width of the first electrode envelope region 131 may decrease curvilinearly from the left side (i.e., the fixed region 124) to the conversion point 133. As shown in FIG. 5D, in the first electrode envelope region 131, the absolute value of the slope of the curve along the outer contour line of the portion above the central axis of the secondary electrode 130-2 gradually decreases as the length increases from the vibration fixing region 124 to the conversion point 133.

[0076] In some embodiments, the width of the electrode in the second electrode envelope region 132 of the two electrode envelope regions increases from the conversion point 133 to the vibration output region 123 and then decreases. The width of the electrode (d4 shown in FIG. 5C) in the second electrode envelope region 132 at a certain position may be the distance between two intersections of a line perpendicular to the central axis along the longitudinal direction of the piezoelectric component 120 at that position and the outer contour line of the electrode 130. In some embodiments, the electrode envelope region between the conversion point 133 and the vibration output region 123 may be the second electrode envelope region 132. In some embodiments, the increase and then decrease in the width of the electrode in the second electrode envelope region 132 may include one or more of the following methods: stepwise change, linear change, or curvilinear change. For example, as shown in FIG. 5C, the width of the electrode in the second electrode envelope region 132 increases curvilinearly from the left side (i.e., the conversion point 133), the increasing width gradually decreases, and when the width reaches the peak value, the width of the electrode decreases curvilinearly and the decreasing width increases and then decreases until the vibration output region 123. As shown in FIG. 5D, in the second electrode envelope region 132, the absolute value of the slope of the curve along the outer contour line of the portion above the central axis of the secondary electrode 130-2 increases from the conversion point 133 with the increase in length and then decreases, the slope of the curve decreases to zero until the widest part of the second electrode envelope region 132, and then, with the increase in length, the absolute value of the slope of the curve increases and then decreases and becomes zero until the vibration output region 123.

[0077] In some embodiments, the electrode 130 may include one or more envelope regions such as a third electrode envelope region and a fourth electrode envelope region, and the shape and quantity of the electrode envelope regions may be determined based on the vibration mode of the piezoelectric component 120 to be controlled.

[0078] In some embodiments, the width of the electrode 130 in the fixed region 124 may be equal to the width of the fixed region 124. As shown in FIGS. 5A and 5C, the width of the fixed region 124 may be D, and correspondingly, the width of the electrode 130 in the fixed region 124 may also be D.

[0079] In some preferred embodiments, the width of the electrode 130 in the fixed region 124 may not be equal to the width of the fixed region 124. For example, the width of the electrode 130 may be smaller than the width of the fixed region 124, or may be larger than the width of the fixed region 124.

[0080] In some embodiments, the width of the electrode 130 in the vibration output region 123 may be zero. As shown in FIGS. 5A and 5C, the width of the electrode 130 in the vibration output region 123 may be zero.

[0081] In some preferred embodiments, the width of the electrode 130 in the vibration output region 123 may not be zero. For example, the width of the electrode 130 in the vibration output region 123 may be smaller than the width of the electrode 130 in the fixed region 124 and larger than zero.

[0082] FIG. 6 is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification. As shown in FIG. 6, curve 1 is the frequency response curve of the vibration output region of the piezoelectric component 120 when the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., the electrode 130 overlaps with the piezoelectric component 120). Curve 2 is the frequency response curve of the piezoelectric component 120 using the primary electrode configuration shown in FIG. 5A, and curve 3 is the frequency response curve of the piezoelectric component 120 using the secondary electrode configuration (the potentials of the two envelope regions are opposite) shown in FIG. 5C.

[0083] As shown in FIG. 6, there are a primary peak and a secondary dip in curve 1. When the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., the electrode 130 overlaps with the piezoelectric component 120), the piezoelectric component 120 has a complex vibration mode in the medium and high frequency range, especially having a vibration response with obvious differences in the range of 500 Hz to 3000 Hz. Using the primary electrode form, the frequency band of the primary mode of the piezoelectric component 120 shown in curve 2 becomes wider, the secondary dip disappears, and narrow-band hopping of the curve occurs at the secondary peak frequency (for example, around 3000 Hz), reducing the amplitude of the secondary peak. Thus, by the installation method of the primary electrode 130-1, the vibration response between the primary peak and the secondary peak of the piezoelectric component 120 can be made flatter. When using the secondary electrode 130-2 (the potentials of the two envelope regions are opposite), the frequency response curve of the piezoelectric component 120 shown in curve 3 is in the secondary vibration form from the low frequency stage (for example, 0 to 100 Hz), and narrow-band hopping of the curve occurs at the primary peak frequency (for example, 500 Hz to 600 Hz), reducing the amplitude of the primary peak. After the peak frequency, it is in the secondary vibration form until the tertiary peak frequency (for example, 9000 hz). Thus, by the installation method of the secondary electrode 130-2, the piezoelectric component 120 may be in the secondary vibration form from the low frequency stage to the tertiary peak. As can be seen from curves 2 and 3, the primary electrode form and the secondary electrode form (the potentials of the two envelope regions are opposite) have a mode control effect. The "peak frequency" in this specification refers to the frequency of the peak (for example, primary peak, secondary peak, tertiary peak, etc.) of the piezoelectric component 120 when the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., the electrode 130 overlaps with the piezoelectric component 120).

[0084] Also, as shown in FIG. 6, curve 4 is the frequency response curve of the piezoelectric component 120 using the secondary electrode 130-2 shown in FIG. 5C (where the potentials of the two envelope regions are the same). Curve 5 is the frequency response curve of the piezoelectric component 120 using a triangular electrode (i.e., an isosceles triangle formed by the center point of the fixed region 124 and the vibration output region 123 of the piezoelectric component 120 as the shape of the electrode). When using a triangular electrode, although there is still a secondary dip in the frequency response curve of the piezoelectric component 120 shown in curve 5, the secondary dip clearly moves backward compared to the case of curve 1 where the electrode completely covers. Thus, by the installation method of the triangular electrode 130, the response between the primary peak frequency and the secondary dip frequency of the piezoelectric component 120 can be made flatter. When using the secondary electrode 130-2 (where the potentials of the two envelope regions are opposite), the frequency response curve of the piezoelectric component 120 shown in curve 4 is similar to curve 1 (where the electrode 130 completely covers one surface of the piezoelectric component 120).

[0085] FIG. 7A is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 when the electrode completely covers one surface of the piezoelectric component (i.e., the electrode overlaps with the piezoelectric component). FIG. 7B is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 using the primary electrode 130-1 according to some embodiments of the present specification. FIG. 7C is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 using the secondary electrode 130-2 according to some embodiments of the present specification.

[0086] Combining FIGS. 6 and 7A-7C, at the secondary dip frequency (e.g., 1622 Hz), when the electrode completely covers one surface of the piezoelectric component (i.e., the electrode overlaps with the piezoelectric component), the variation in the vibration response of the piezoelectric component 120 is large and the frequency response curve is not flat. The variation in the vibration response of the piezoelectric component 120 with electrode design (e.g., primary electrode 130-1 or secondary electrode 130-2) is small, the frequency response curve is flatter, and nodes are less likely to be formed.

[0087] In the embodiments of this specification, by designing the electrode 130 as the mode actuator of the piezoelectric component 120, the piezoelectric component 120 can generate only the excitation force of a specific mode and output the vibration form of the specific mode, thereby improving the voice characteristics of the acoustic device. And since the frequency response curve of the piezoelectric component 120 becomes more stable, the formation of nodes in the vibration output region 123 of the piezoelectric component 120 can be avoided, and the operation reliability of the acoustic device 100 can be improved.

[0088] And compared with adding a mode control system composed of mechanical structures such as springs, masses, and damping elements to a specific region, the embodiments of this specification can realize the mode control of the piezoelectric component 120 by designing the electrode 130, and simplify the structure of the acoustic device 100.

[0089] In some embodiments, the piezoelectric component 120 may be designed based on the design of the electrode 130. Hereinafter, specific implementation manners for designing the piezoelectric component 120 will be described in detail by taking a plurality of exemplary designs using the one-dimensional primary electrode 130-1 as examples.

[0090] FIG. 8A is a schematic configuration diagram of the electrode 130 and the piezoelectric component 120 according to some embodiments of this specification. FIG. 8B is a schematic configuration diagram of the electrode 130 and the piezoelectric component 120 according to some embodiments of this specification. FIG. 8C is a schematic configuration diagram of the electrode 130 and the piezoelectric component 120 according to some embodiments of this specification. FIG. 8D is an exploded structure schematic diagram of the electrode 130 and the piezoelectric component 120 according to some embodiments of this specification. It should be understood that the triangular regions (or similar triangular regions) in FIGS. 8A to 8D are merely exemplary and do not limit the shape of the electrode.

[0091] In some embodiments, as shown in FIG. 3, the substrate 121 may be rectangular, the piezoelectric layer 122 may be a piezoelectric rectangular beam overlapping the substrate 121 (where the piezoelectric layer 122 is all in the piezoelectric region), and the electrode 130 may be the primary electrode 130-1, that is, the covering area of the electrode 130 (shown in the similar triangular region) < the covering area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122.

[0092] In some embodiments, as shown in FIG. 8A, 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 primary 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). The piezoelectric region 1221 overlaps with the primary electrode 130-1 (the dashed line inside the piezoelectric region 1221 is only for distinguishing the piezoelectric region 1221 from the electrode 130 and does not limit their sizes), that is, the covered area of the electrode 130 (shown in the similar triangular region) = the covered area of the piezoelectric region 1221 < the covered area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122.

[0093] In some embodiments, as shown in FIG. 8B, the substrate 121 may be rectangular, the electrode 130 may be a primary electrode 130-1, the piezoelectric layer 122 may overlap with the electrode 130, and the covered areas of both the electrode 130 and the piezoelectric layer 122 are smaller than the surface area of the substrate 121 covered by the piezoelectric layer 122, that is, the covered area of the electrode 130 (shown in the similar triangular region) = the covered area of the piezoelectric layer 122 < the surface area of the substrate 121 covered by the piezoelectric layer 122. That is, the piezoelectric material in the region of the piezoelectric layer 122 not covered by the electrode is removed, and the substrate is retained as a rectangular beam.

[0094] In some embodiments, as shown in FIG. 8C, the electrode 130 may be a primary electrode 130-1, and both the substrate 121 and the piezoelectric layer 122 may overlap with the electrode 130, that is, the covered area of the electrode 130 (shown in the similar triangular region) = the covered area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122.

[0095] In some embodiments, the piezoelectric layer 122 may overlap 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 covered by the piezoelectric layer 122. In some preferred embodiments, the piezoelectric layer 122 may not overlap 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.

[0096] In some embodiments, the piezoelectric layer 122 may all be piezoelectric regions. For example, as shown in FIG. 3, FIG. 8B or FIG. 8C, the piezoelectric layer 122 may all be supported by piezoelectric materials. 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.

[0097] In some embodiments, the piezoelectric region 1221 may overlap with the electrode 130. For example, as shown in FIG. 8A, the piezoelectric region 1221 of the piezoelectric layer 122 and the electrode 130 have equal coverage areas and spatially overlap each other.

[0098] In some embodiments, the piezoelectric layer 122 may overlap with the electrode 130. For example, as shown in FIG. 8B or FIG. 8C, the piezoelectric layer 122 and the electrode 130 have equal coverage areas and spatially overlap each other.

[0099] In some embodiments, by designing the coating shape of the electrode 130 and the piezoelectric region, the effective electrode portion of the electrode 130 can generate a specific mode with respect to the piezoelectric component 120. 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 coating 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 region and the non-piezoelectric region is equal to the coating area of the electrode 130 on the piezoelectric layer 122, that is, the electrode 130 and the piezoelectric layer 122 overlap. In some embodiments, the coating area of the piezoelectric region on the substrate 121 may be smaller than the coating 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. The shape and area of the piezoelectric region 1221 (shown in the hatched area) limit the effective area of the rectangular electrode 130, that is, the area of the piezoelectric region 1221 < the coating area of the piezoelectric layer 122 = the coating area of the electrode 130 = the surface area of the substrate 121 covered by the piezoelectric layer 122. A part of the electrode 130 covering the piezoelectric region 1221 can supply a driving voltage to the piezoelectric component 120, that is, this part of the electrode 130 may be an effective electrode portion. Since a part of the electrode 130 covering the non-piezoelectric region 1222 is merely a conductive component that transmits electrical energy to the effective electrode portion, the coating 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 way, by realizing the design of the electrode 130 in the manner of designing the piezoelectric region 1221, a part of the electrode 130 covering the piezoelectric region 122 can control the piezoelectric component 120 to output a specific mode.

[0100] FIG. 9 is a schematic diagram of the frequency response curve of the piezoelectric component 120 according to some embodiments of the present specification. In some embodiments, curve 6 is the frequency response curve of the piezoelectric component 120 when the rectangular electrode completely covers one surface of the rectangular piezoelectric component (i.e., the electrode, the piezoelectric component, and the substrate all overlap). Curve 7 is the frequency response curve of the piezoelectric component 120 shown in FIG. 3 above (i.e., the covered area of the electrode 130 < the covered area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122), curve 8 is the frequency response curve of the piezoelectric component 120 shown in FIG. 8A or FIG. 8D above (i.e., the covered area of the electrode 130 = the covered area of the piezoelectric region 1221 < the covered area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122 or the area of the piezoelectric region < the covered area of the piezoelectric layer 122 = the covered area of the electrode 130 = the surface area of the substrate 121 covered by the piezoelectric layer 122), curve 9 is the frequency response curve of the piezoelectric component 120 shown in FIG. 8B above (i.e., the covered area of the electrode 130 = the covered area of the piezoelectric layer 122 < the surface area of the substrate 121 covered by the piezoelectric layer 122), and curve 10 is the frequency response curve of the piezoelectric component 120 shown in FIG. 8C above (i.e., the covered area of the electrode 130 = the covered area of the piezoelectric layer 122 = the surface area of the substrate 121 covered by the piezoelectric layer 122).

[0101] As shown in FIG. 9, when the electrode completely covers one surface of the piezoelectric component (i.e., the electrode overlaps the piezoelectric component), there are a primary peak and a secondary dip in the frequency response curve of the piezoelectric component 120 shown by curve 6, and the piezoelectric component 120 has multiple modes. The frequency response characteristics of curve 7 and curve 8 are similar, which can reflect that replacing the piezoelectric material in the region not covered by the electrode with a non-piezoelectric material (or limiting the effective area of the electrode by the shape of the piezoelectric region) can make the characteristics of the frequency response curve similar compared to the case where all is piezoelectric material. The frequency response amplitude of curve 9 increases significantly, the low-frequency peak moves to a high frequency, the secondary mode is significantly suppressed, and smoothly transitions to the tertiary dip, which can reflect that removing the piezoelectric material in the region not covered by the electrode 130, making the piezoelectric layer 122 and the electrode 130 overlap, and making the covered area of the piezoelectric layer 122 (or the electrode 130) smaller than the surface area of the substrate 121 covered by the piezoelectric layer 122 can play a mode control effect. There are still a primary peak and a secondary dip in the frequency response curve shown in FIG. 10, and still has multiple modes, which can reflect that when the substrate 121, the piezoelectric layer 122, and the electrode 130 are all in the shape of the primary electrode 130-1, its frequency response characteristics are consistent with the frequency response characteristics when the electrode completely covers one surface of the piezoelectric component (i.e., the electrode overlaps the piezoelectric component). Therefore, the shape of the primary electrode 130-1 may affect the vibration mode of the rectangular piezoelectric cantilever beam, but cannot play a control effect on the vibration mode of the piezoelectric cantilever beam with the same shape (e.g., the shape of the primary electrode 130-1).

[0102] In some embodiments, the piezoelectric layer 122 has the same rule for the potential distribution when the piezoelectric layer 122 is covered with the primary electrode 130-1 and when the piezoelectric region 1221 is covered with the primary electrode 130-1 and the other regions of the piezoelectric layer 122 are replaced with non-piezoelectric regions 1222 made of non-piezoelectric materials. For example, when the vibration frequency of the piezoelectric component 120 is about 100 Hz, there is no potential difference in the region of the piezoelectric layer 122 not covered by the primary electrode 130-1 of the piezoelectric component 120 shown in FIG. 3. When the material of the region of the piezoelectric layer 122 not covered by the electrode 130 shown in FIG. 8A is replaced with a non-piezoelectric material, the non-piezoelectric region not covered by the electrode has no electrical performance.

[0103] In the embodiments of the present specification, the piezoelectric component 120 may be designed according to the design of the electrode 130. By replacing the piezoelectric material with a non-piezoelectric material for the region of the piezoelectric component 120 not covered by the electrode, it is ensured that the piezoelectric component 120 can output vibration normally and the manufacturing cost of the piezoelectric component 120 is reduced.

[0104] FIG. 10 is a schematic configuration diagram of a piezoelectric component 120 with an exemplary mass block model 140 added according to some embodiments of the present specification.

[0105] In some embodiments, the vibration output region of the piezoelectric component 120 may be connected to the vibration component 110 and / or other components. In some embodiments, in order to design the contour curve of the electrode 130, the vibration component 110 and / or other components may be simplified into a mass block model 140. Exemplarily, as shown in FIG. 10, the vibration output region 123 of the piezoelectric component 120 is connected to the mass block model 140. The mass block model 140 can transmit vibration and output vibration through its own second vibration output region 141. In some embodiments, the second vibration output region 141 may include one side, one edge or one point of the mass block model 140, etc., or any combination thereof. As shown in FIG. 10, the second vibration output region 141 may include the center point of the mass block model 140. For the specific implementation manner of the second vibration output region 141, reference can be made to the related description in FIGS. 3-4 above, so the description is omitted here.

[0106] In some embodiments, based on the mass relationship between the piezoelectric component 120 and the mass block model 140, and the vibration structure of the piezoelectric component 120, the contour curve of the electrode 130 can be determined to perform mode control on the piezoelectric component 120. In some embodiments, the mass relationship between the piezoelectric component 120 and the mass block model 140 may include the ratio of the mass of the mass block model 140 to the mass of the piezoelectric component 120, that is, 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. Hereinafter, taking the piezoelectric cantilever beam shown in FIG. 10 as an example, several exemplary primary electrodes 130-1 and secondary electrodes 130-2 are provided respectively to explain the specific implementation manner of the mass ratio in detail.

[0107] FIG. 11A is a schematic shape diagram of an exemplary primary electrode 130-1 according to some embodiments of the present specification. FIG. 11B is a schematic shape diagram of an exemplary secondary electrode 130-2 according to some embodiments of the present specification.

[0108] As shown in FIG. 11A, curve 11 is the contour curve of the primary electrode 130-1 when the mass block model 140 with a mass ratio α = 0.5 is added, curve 12 is the contour curve of the primary electrode 130-1 when the mass block model 140 with a mass ratio α = 1 is added, and curve 13 is the contour curve of the primary electrode 130-1 when the mass block model 140 with a mass ratio α = 2 is added. As shown in FIG. 11B, curve 14 is the contour curve of the secondary electrode 130-2 when the mass block model 140 with a mass ratio α = 0.5 is added, curve 15 is the contour curve of the secondary electrode 130-2 when the mass block model 140 with a mass ratio α = 1 is added, and curve 16 is the contour curve of the secondary electrode 130-2 when the mass block model 140 with a mass ratio α = 2 is added.

[0109] In some embodiments, with the change of the mass ratio α, the shape of the electrode 130 may change. For example, the greater the mass ratio α between the mass block model 140 and the piezoelectric component 120, the flatter the change in the width of the electrode 130 becomes. Exemplarily, as shown in FIG. 11A, from curve 11 to curve 13, the mass ratio α between the mass block model 140 and the piezoelectric component 120 increases, the curvature of the contour curve of the primary electrode 130-1 decreases, that is, the change in the contour curve of the primary electrode 130-1 becomes flatter.

[0110] Exemplarily, as shown in FIG. 11B, from curve 14 to curve 16, the mass ratio α between the mass block model 140 and the piezoelectric component 120 increases, and the curvature of the contour curve of the secondary electrode 130-2 decreases when it decreases from the fixed region 124 to the conversion point 133. And the curvature of the contour curve of the secondary electrode 130-2 decreases when it increases from the conversion point 133 to the vibration output region 123, and the curvature decreases when it decreases, that is, the change in the contour curve of the secondary electrode 130-2 is flatter. For the specific implementation of the contour curve of the above electrode 130, reference can be made to the relevant descriptions in FIGS. 5A-5D above, so the description is omitted here.

[0111] In some embodiments, when the mass block model 140 is added to the piezoelectric component 120, without considering the mass relationship between the piezoelectric component 120 and the mass block model 140, based only on the vibration structure of the piezoelectric component 120, the contour curve of the electrode 130 may be determined, and mode control can also be performed on the piezoelectric component 120. For the specific implementation method of electrode design without considering the mass ratio, reference can be made to the relevant descriptions in FIGS. 12 to 13D, so the description is omitted here.

[0112] FIG. 12 is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification.

[0113] As shown in FIG. 12, curve 17 is the frequency response curve of the piezoelectric component 120 with the electrode 130 completely covering one surface of the piezoelectric component 120 (that is, the electrode 130 overlaps the piezoelectric component 120, and both are rectangular), and the mass block model 140 is added. Curve 18 is the frequency response curve of the piezoelectric component 120 with the mass block model 140 having a mass ratio α = 0.5 added and using the primary electrode 130-1 shown in FIG. 11A. Curve 19 is the frequency response curve of the piezoelectric component 120 with the mass block model 140 having a mass ratio α = 1 added and using the primary electrode 130-1 shown in FIG. 11A. Curve 20 is the frequency response curve of the piezoelectric component 120 with the mass block model 140 having a mass ratio α = 2 added and using the primary electrode 130-1 shown in FIG. 11A. Curve 21 is the frequency response curve of the piezoelectric component 120 using the primary electrode 130-1 shown in FIG. 5A (that is, the electrode shape calculated when the mass block model 140 is not added), but with the mass block model 140 having a mass ratio α = 0.5 added. Curve 22 is the frequency response curve of the piezoelectric component 120 with the mass block model 140 having a mass ratio α = 0.5 added and using the secondary electrode 130-2 shown in FIG. 11B.

[0114] As shown in FIG. 12, there are a primary peak and a secondary dip in curve 17, which can reflect that the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., the electrode 130 overlaps with the piezoelectric component 120), and the piezoelectric component 120 with the mass block model 140 added still has multiple modes.

[0115] As shown in FIG. 12, when using the primary electrode 130-1 designed for the case where the mass block model 140 is added, the piezoelectric components 120 shown in curves 18 to 20 all smoothly transition from the primary peak to the secondary peak frequency (for example, around 1000 Hz), small hopping occurs up to the secondary peak frequency, and then continue to smoothly transition to the tertiary dip. And at the secondary peak frequency and the tertiary peak frequency (for example, around 7000 Hz), the amplitudes of the frequency response curves of the piezoelectric components 120 shown in curves 18 to 20 all significantly decrease.

[0116] And as the mass ratio α increases, the frequency corresponding to the primary peak of the frequency response curve of the piezoelectric component 120 shown in curves 18 to 20 becomes lower and lower, the amplitude also becomes lower and lower from the primary peak backward, and the frequency response curve becomes more and more flat in the changing trend after hopping at the secondary peak frequency, which can reflect that the higher the mass ratio α, the higher the mode control effect of the piezoelectric component 120 using the primary electrode 130-1 designed for the case where the mass block model 140 is added.

[0117] As shown in FIG. 12, when using the primary electrode 130-1 designed without adding the mass block model 140, the frequency response curve of the piezoelectric component with the mass block model 140 added, where the mass ratio α = 0.5 as shown by curve 21, can smoothly transition at the frequency corresponding to the secondary dip, but the amplitude and bandwidth of the hopping clearly increase at the secondary peak frequency. This reflects that although the primary electrode 130-1 designed without adding the mass block model 140 can still realize the mode control of the secondary dip of the piezoelectric component 120, the suppression effect on the higher-order mode by the primary electrode 130-1 may decrease.

[0118] When using the secondary electrode 130-2 designed with the mass block model 140 added, the frequency response curve of the piezoelectric component 120 shown by curve 22 is similar to the frequency response curve of the piezoelectric component 120 without adding the mass block model 140 shown by curve 3 in FIG. 6 above. It is in the secondary vibration mode in the low frequency band (for example, 0 to 100 Hz), and narrow-band hopping of the curve occurs at the primary peak frequency (for example, between 100 Hz and 200 Hz), reducing the amplitude of the primary peak. From the peak frequency to the third peak frequency (for example, between 6000 Hz and 7000 Hz), it is in the secondary vibration mode, which can reflect that the piezoelectric component 120 using the secondary electrode 130-2 (the potentials of the two envelope regions are opposite) designed with the mass block model 140 added with a mass ratio α = 0.5 can control the secondary vibration mode.

[0119] FIG. 13A is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 when the mass block model 140 is added and the electrode completely covers one surface of the piezoelectric component 120 (i.e., the electrode 130 overlaps the piezoelectric component 120) according to some embodiments of the present specification. FIG. 13B is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 using the primary electrode 130-1 designed when the mass block model 140 is added according to some embodiments of the present specification. FIG. 13C is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 using the secondary electrode 130-2 designed when the mass block model 140 is not added according to some embodiments of the present specification. FIG. 13D is a vibration mode diagram at the secondary dip frequency of the piezoelectric component 120 using the secondary electrode 130-2 designed when the mass block model 140 is added according to some embodiments of the present specification.

[0120] Combining FIGS. 12 and 16A to 16D, at the secondary dip frequency (e.g., 1411 Hz), when the electrode completely covers one surface of the piezoelectric component (i.e., the rectangular electrode overlaps the rectangular piezoelectric component), for the piezoelectric component 120 with the added mass block model 140, during vibration, the variation of the vibration response is large, the frequency response curve is not flat, nodes are formed at a certain frequency in the vibration output region 123, which may affect the effect of the acoustic output. When using the primary electrode 130-1 designed when the mass block model 140 is added (or the primary electrode 130-1 designed when the mass block model 140 is added, the secondary electrode 130-2, or the primary electrode 130-1 designed when the mass block model 140 is not added), for the piezoelectric component 120 with the added mass block model 140, during vibration, the variation of the vibration response of the piezoelectric component 120 is small, the frequency response curve is flatter, and it is difficult to form nodes.

[0121] Also, as shown in FIG. 13C, when using the primary electrode 130-1 designed for the case where the mass block model 140 is not added, the piezoelectric component 120 with the added mass block model 140 tends to change its vibration mode to a secondary vibration mode during vibration. This indicates that although the primary electrode 130-1 designed for the case where the mass block model 140 is not added can still achieve mode control of the piezoelectric component 120, it can be reflected that the suppression effect on the higher-order mode by the primary electrode 130-1 may decrease.

[0122] In the embodiments of this specification, by designing the electrode 130 based on the mass ratio α between the mass block model 140 and the piezoelectric component 120, the piezoelectric component 120 can generate a more accurate excitation force for a specific mode, further improving the mode control effect. And it can reduce the amplitude at the fixed frequency of the frequency response curve of the piezoelectric component 120, avoid the formation of nodes in the vibration output region 123 of the piezoelectric component 120, and further improve the operation reliability of the acoustic device 100.

[0123] In some embodiments, the piezoelectric component 120 may include a piezoelectric plate or a piezoelectric film. In some embodiments, the shape of the electrode 130 may be determined based on the size of the piezoelectric plate or piezoelectric film and the vibration mode function of the vibration structure. For example, by designing the electrode 130 coated on the piezoelectric plate or piezoelectric film into a plurality of distributed electrode units (also referred to as "two-dimensional electrodes") distributed two-dimensionally, the piezoelectric component 120 can generate a specific mode.

[0124] Hereinafter, taking the piezoelectric component 120 shown in FIG. 4 as an example, exemplary distributed electrode units 134 and continuous electrodes are respectively provided to detail the specific implementation manners of the design of the two-dimensional electrode.

[0125] In some embodiments, the electrode 130 may include a plurality of distributed electrode units 134 that are two-dimensionally distributed. In some embodiments, the plurality of distributed electrode units 134 may be separated from each other and configured as a conductive material distributed on the surface of the piezoelectric component 120. In some embodiments, the shape of the distributed electrode unit 134 may include one of a circle, a triangle, a quadrilateral, an irregular shape, etc., or any combination thereof.

[0126] FIG. 14A is a schematic configuration diagram of a part of an exemplary two-dimensional electrode 130 according to some embodiments of the present specification, FIG. 14B is a schematic configuration diagram of a part of an exemplary two-dimensional electrode 130 according to some embodiments of the present specification, FIG. 14C is a schematic configuration diagram of a part of an exemplary two-dimensional electrode 130 according to some embodiments of the present specification, and FIG. 14D is a schematic configuration diagram of a part of an exemplary two-dimensional electrode 130 according to some embodiments of the present specification.

[0127] FIG. 14A shows a quarter of a square piezoelectric layer. The piezoelectric layer 122 (e.g., a square piezoelectric sheet with a size of 18×18×0.09 mm) overlaps with the substrate 121 (e.g., a steel substrate with a size of 18×18×0.05 mm), and the peripheral edge of the substrate is the fixed region 124. FIG. 14B shows a quarter of a square piezoelectric layer. The piezoelectric layer 122 (e.g., a square piezoelectric sheet with a size of 18×18×0.09 mm) covers the substrate 121 (e.g., a steel substrate with a size of 23×23×0.05 mm). The covered area of the piezoelectric layer 122 is smaller than the surface area of the substrate 121 covered by the piezoelectric layer, and the peripheral edge of the substrate is the fixed region 124. FIGS. 14C and 14D show a rectangular piezoelectric layer respectively. The piezoelectric layer 122 (e.g., a rectangular piezoelectric plate with a size of 40×20×0.5 mm) overlaps with the substrate 121 (e.g., a steel substrate with a size of 40×20×0.1 mm), and the peripheral edge of the substrate is the fixed region 124. The rectangular piezoelectric plate shown in FIG. 14D is in the (3,1) mode. In this specification, the "3" in the "(3,1) mode" refers to the fact that the longitudinal direction is in the third mode, that is, when the rectangular piezoelectric plate is simplified to a cantilever beam (ignoring the width) along the longitudinal direction, it has the third mode. The "1" refers to the fact that the width direction is in the first mode, that is, when the rectangular piezoelectric plate is simplified to a cantilever beam (ignoring the length) along the width direction, it has the first mode.

[0128] In some embodiments, in the plurality of distributed electrode units 134, the gap between two adjacent distributed electrode units 134 at the center of the piezoelectric layer 122 is smaller than the gap between two adjacent distributed electrode units 134 at the boundary of the piezoelectric layer 122. Here, the above "center of the piezoelectric layer 122" may be the geometric center of the piezoelectric layer 122, may be the vibration amplitude output position of each 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 three centers each corresponding to the vibration center of the primary vibration mode. Therefore, here, the above "boundary of the piezoelectric layer 122" may be the geometric boundary of the piezoelectric layer 122, may be the region where the vibration output of each mode of the piezoelectric layer 122 is the smallest, or may be the boundary of the fixed region 124. For example, when the piezoelectric layer 122 is in the (3,1) mode (that is, the third mode in the longitudinal direction and the first mode in the width direction), the boundary of the piezoelectric layer 122 may be the boundary of the region corresponding to each vibration mode. For example, as shown in FIGS. 14A to 14C, the gap between two adjacent distributed electrode units 134 at the geometric center of the piezoelectric layer 122 is the distance D1, and the gap between two adjacent distributed electrode units 134 at the boundary is the distance D2, and the distance D1 is smaller than the distance D2. Also, for example, as shown in FIG. 14D, the gap between two adjacent distributed electrode units 134 at each vibration center of the piezoelectric layer 122 is the distance D1, and the gap between two adjacent distributed electrode units 134 at the boundary of the region corresponding to the vibration center is the distance D2, and the distance D1 is smaller than the distance D2. In some embodiments, the gap between two adjacent distributed electrode units gradually increases from the center to the boundary of the piezoelectric layer 122. For example, the gap between two adjacent distributed electrode units close to the center of the piezoelectric layer 122 is smaller than the gap between two adjacent distributed electrode units away from the center of the piezoelectric layer 122.

[0129] In some embodiments, the area of the distributed electrode unit 134 may be related to the vibration displacement amount of the region where the distributed electrode unit 134 is located at a specific frequency (for example, the primary peak, the secondary peak). The vibration displacement amount refers to the distance change that occurs when the piezoelectric layer 122 vibrates with respect to the horizontal plane when it is not vibrating. In some embodiments, the area of the first distributed electrode unit 1341 at the center of the piezoelectric layer 122 is larger than the area of the second distributed electrode unit 1342 at the boundary of the piezoelectric layer 122. For example, as shown in FIGS. 14A to 14D, since the first distributed electrode unit 1341 is closer to the vibration output region 123 than the second distributed electrode unit 1342, during vibration, the displacement amount of the first distributed electrode unit 1341 is larger than the displacement amount of the second distributed electrode unit 1342, and the area of the first distributed electrode unit 1341 may be larger than the area of the second distributed electrode unit 1342.

[0130] In some embodiments, regarding the area of the distributed electrode unit 134, based on the difference (for example, the displacement ratio) between the vibration displacement amount of the region where the distributed electrode unit 134 is located and the maximum displacement amount of the piezoelectric layer 122 at a specific frequency (for example, the primary peak, the secondary peak), the area of the distributed electrode unit 134 in each region can be determined. Exemplarily, the piezoelectric layer 122 can be dispersed into m×n piezoelectric sub-regions, that is, m×n distributed electrode units 134. Based on the difference between the displacement amount of each piezoelectric sub-region and the maximum displacement amount of the piezoelectric layer 122, the piezoelectric sub-regions are enlarged and reduced at an equal ratio to determine the area of the distributed electrode unit 134 in the piezoelectric sub-region.

[0131] In some embodiments, the potential of the distributed electrode unit 134 may be related to the displacement direction of the piezoelectric sub-region where the distributed electrode unit 134 is located. Exemplarily, as shown in FIG. 14D, during the vibration of the piezoelectric component 120, if the displacement direction of the third distributed electrode unit 1343 is opposite to the maximum displacement direction of the piezoelectric layer 122, and the displacement direction of the fourth distributed electrode unit 1344 is the same as the maximum displacement direction of the piezoelectric layer 122, the potential direction of the third distributed electrode unit 1343 is opposite to the potential direction of the fourth distributed electrode unit 1344.

[0132] Hereinafter, taking the piezoelectric component 120 and the size of the substrate shown in FIGS. 14A and 14B as an example, the distinction of the frequency response curves when the distributed electrode units with different shapes or quantities are respectively coated will be described.

[0133] FIG. 15A is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification, FIG. 15B is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification, FIG. 15C is a schematic diagram of the vibration displacement of a piezoelectric component coated with an integrated electrode at 5380.3 Hz according to some embodiments of the present specification, and FIG. 15D is a schematic diagram of the vibration displacement of a piezoelectric component coated with an 8×8 distributed electrode unit at 5380.3 Hz according to some embodiments of the present specification.

[0134] As shown in FIG. 15A, curve 23 is the frequency response curve of the piezoelectric component 120 when the piezoelectric layer 122 shown in FIG. 14A overlaps the substrate 121 and the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., an integrated electrode), curve 24 is the frequency response curve of the piezoelectric component 120 coated with an 8×8 distributed electrode unit 134 when the piezoelectric layer 122 shown in FIG. 14A overlaps the substrate 121, and curve 25 is the frequency response curve of the piezoelectric component 120 coated with a 32×32 distributed electrode unit 134 when the piezoelectric layer 122 shown in FIG. 14A overlaps the substrate 121.

[0135] As shown in FIG. 15A, a resonance dip appears in the frequency response curve of the piezoelectric component 120 shown by curve 23, and split vibration occurs at the frequency corresponding to the resonance dip (for example, about 5380.3 Hz). This can reflect that when the electrode 130 completely covers one surface of the piezoelectric component 120, the central region of the piezoelectric layer 122 is out of phase with the surrounding vibration, and the vibration areas are the same, which easily causes the inverse-phase cancellation of the emitted sound pressure of the piezoelectric component 120 in the vibration output region and makes it difficult to output vibration.

[0136] The frequency response curves of the piezoelectric component 120 shown in curves 24 to 25 form a smooth sound pressure level frequency response curve between the primary peak (e.g., 3500 Hz) and the secondary peak (e.g., about 10000 Hz), and the amplitude near the resonance dip frequency can be increased, which means that the two-dimensional electrode 130 expands the frequency width of the piston vibration of the piezoelectric component 120 so as to still maintain the primary piston vibration at the frequency corresponding to the original resonance dip (e.g., about 5380.3 Hz), and realizes mode control by effectively outputting the emitted sound pressure. The "piston vibration" in this specification refers to the situation where each region of the piezoelectric component 120 (e.g., piezoelectric plate) vibrates up and down simultaneously (the displacement directions are the same) in the same manner as a piston when vibrating.

[0137] Also, the low-frequency amplitude before the primary peak (e.g., before 2000 Hz) of the frequency response curve of the piezoelectric component 120 shown in curves 24 to 25 increases, and the bandwidth of the entire secondary peak and the subsequent resonance dip (e.g., after 10000 Hz) becomes smaller, which can reflect that the two-dimensional electrode 130 can improve the low-frequency response of the piezoelectric component 120 and suppress the inherent mode vibration form at the secondary peak frequency of the piezoelectric component 120.

[0138] Also, the frequency response curve of the piezoelectric component 120 shown in curve 25 has a higher low-frequency response amplitude before the primary peak (e.g., before 2000 Hz) and further suppresses the amplitude and bandwidth at the secondary peak frequency (e.g., about 10000 Hz) compared with the frequency response curve of the piezoelectric component 120 shown in curve 24, which can reflect that the piezoelectric component 120 using the 32×32 two-dimensional electrode 130 has a higher low-frequency response and further plays a suppressing role on the high-frequency mode compared with the 8×8 two-dimensional electrode 130.

[0139] As shown in FIG. 15B, when the covered area of the piezoelectric layer 122 shown in FIG. 14B is smaller than the area of the surface of the substrate 121 covered by the piezoelectric layer, the curve 23' is the frequency response curve of the piezoelectric component 120 when the electrode 130 completely covers one surface of the piezoelectric component 120 (i.e., an integral electrode). The curve 24' is the frequency response curve of the piezoelectric component 120 covered with the 8×8 distributed electrode unit 134 when the covered area of the piezoelectric layer 122 shown in FIG. 14B is smaller than the area of the surface of the substrate 121 covered by the piezoelectric layer. The curve 25' is the frequency response curve of the piezoelectric component 120 covered with the 32×32 distributed electrode unit 134 when the covered area of the piezoelectric layer 122 shown in FIG. 14B is smaller than the area of the surface of the substrate 121 covered by the piezoelectric layer.

[0140] As shown in FIG. 15B, in the frequency response curve of the piezoelectric component 120 shown by the curve 23', at 4189.8 Hz, split vibrations with a vibration mode similar to that of the curve 23 occur, causing the cancellation of the reverse phase of the sound pressure in the vibration output region and forming a resonance dip. According to the curves 24' and 25', the two-dimensional electrode realizes the expansion of the piston vibration frequency band so that it is still in the piston vibration at the original resonance dip frequency point, and the sound pressure level smoothly transitions in this frequency band. In the frequency response curve of the piezoelectric component 120 shown by the curve 23', the sound pressure level near 6000 Hz after the secondary peak is a flat curve. When using the two-dimensional electrode, resonance dips are formed in the curves 24' and 25'. The reason for this phenomenon is that in the case of the integral electrode, the vibration mode here is to output vibration by the resonance of the part exceeding the piezoelectric layer 122 of the substrate 121. However, when the two-dimensional electrode changes the vibration mode of the piezoelectric layer 122 and combines with the elasticity provided by the edge substrate 121, a vibration form in which the vibrations of the intermediate region and the surrounding region are in reverse phase is formed, resulting in the cancellation of the reverse phase of the sound pressure in the vibration output region, appearing as a resonance dip on the curve, and having a certain influence on the directivity.

[0141] As shown in FIGS. 15C and 15D, when the integrated electrode is coated, the piezoelectric component 120 generates split vibration at 5380.3 Hz, the vibrations in the intermediate region and the surrounding region are out of phase, and the areas are the same, causing the sound pressure in the vibration output region to cancel out due to the out-of-phase of the sound pressure. When the two-dimensional electrode of the 8×8 distributed electrode unit 134 is coated, the piezoelectric component 120 is still in piston vibration at 5380.3 Hz, and by effectively outputting the sound pressure, the sound pressure level amplitude in the vibration output region is significantly improved.

[0142] FIG. 16A is a vibration mode diagram of the primary mode of the piezoelectric component 120 when the electrode completely covers (i.e., uses an integrated electrode) the rectangular piezoelectric component 120 according to some embodiments of the present specification. FIG. 16B is a vibration mode diagram at high frequency of the piezoelectric component 120 when the electrode completely covers (i.e., uses an integrated electrode) the rectangular piezoelectric component 120 according to some embodiments of the present specification. FIG. 16C is a vibration mode diagram at high frequency of the piezoelectric component 120 when the distributed electrode unit 134 of 16×8 two-dimensional electrodes 130 is used for the rectangular piezoelectric component 120 according to some embodiments of the present specification. FIG. 16D is a vibration mode diagram at high frequency of the piezoelectric component 120 when the distributed electrode unit 134 of 32×16 two-dimensional electrodes 130 is used for the rectangular piezoelectric component 120 according to some embodiments of the present specification.

[0143] FIG. 16A shows the primary mode at 6907 Hz of the rectangular piezoelectric component 120 using an integrated electrode, and FIG. 16B shows the vibration mode at a higher frequency of 18326 Hz of the rectangular piezoelectric component 120 using an integrated electrode. By coating with the two-dimensional electrode 130, the vibration mode at 18326 Hz exhibits a vibration mode similar to the primary vibration mode shown in FIG. 16A. Since the 32×16 distributed electrode unit has more and more continuously changing than the 16×8 distributed electrode unit, the piezoelectric component 120 coated by the 32×16 distributed electrode unit has a vibration mode closer to the primary vibration mode at 18326 Hz.

[0144] In the embodiments of this specification, by realizing the design of the two-dimensional electrode 130 by utilizing the two-dimensional distribution of a plurality of distributed electrode units 134, the piezoelectric component 120 can output only a vibration mode of a specific mode, and the voice characteristics of the acoustic device 100 can be further improved.

[0145] And, since the frequency response curve of the piezoelectric component 120 becomes more stable, the formation of nodes in the vibration output region 123 due to the vibration of the inverse phase between the intermediate region and the surrounding region of the piezoelectric component 120 can be avoided, and the operation reliability of the acoustic device 100 can be improved.

[0146] FIG. 17A is a schematic diagram of the design concept of the distributed electrode unit 134 of the exemplary two-dimensional electrode 130 according to some embodiments of this specification, FIG. 17B is a schematic configuration diagram of the distributed electrode unit 134 of the exemplary two-dimensional electrode 130 according to some embodiments of this specification, and FIG. 17C is a schematic shape diagram of the primary electrode 130-1 corresponding to a rectangle corresponding to a fixed-fixed beam at both ends according to some embodiments of this specification.

[0147] As shown in FIG. 17A, the piezoelectric component 120 can be divided into 16 rectangles (by 15 dashed lines) in the longitudinal direction (the horizontal direction in FIG. 17A). All 16 rectangles have the width of the piezoelectric component 120 as the length and equally divide the length of the piezoelectric component 120. Similarly, in the width direction (the vertical direction in FIG. 17A), the piezoelectric component 120 is divided into 8 rectangles (by 7 dashed lines). The 16 rectangles in the longitudinal direction and the 8 rectangles in the width direction may each correspond to a fixed-fixed beam. As shown in FIG. 7, along the longitudinal direction, the width of the rectangular fixed beam gradually increases from zero to a certain value and then gradually decreases to zero from another fixed region 124 to another fixed region 124, forming a "spindle shape". In some embodiments, the increase or decrease in width may include one or any combination of the following, such as the width increasing or decreasing stepwise, linearly, or curvilinearly. It should be understood that FIG. 17C shows only the shape of the electrodes in the longitudinal direction, and the fixed beams of each rectangle in the width direction may have a similar shape. In some embodiments, based on the shape of the primary electrode 130-1 shown in FIG. 17C, the first shape 171 (the 16-column spindle shape in FIG. 17A) in the longitudinal direction of the plurality of distributed electrode units 134 and the second shape 172 (the 8-row spindle shape in FIG. 17A) in the width direction of the plurality of distributed electrode units 134 are determined. Based on the first shape 171 and the second shape 172, the two-dimensional electrode 130 is determined. As shown in FIG. 17B, the two-dimensional electrode 130 is the overlapping region of the first shape 171 and the second shape 172, and each overlapping region may be a distributed electrode unit 134.

[0148] FIG. 18 is a vibration mode diagram of the piezoelectric component 120 covered with the two-dimensional electrode 130 shown in FIG. 17B according to some embodiments of the present specification.

[0149] As shown in FIG. 18, the piezoelectric component 120 coated with the two-dimensional electrode 130 shown in FIG. 17B can effectively output sound pressure because the vibration mode in the high-frequency band (for example, 18326 Hz) is still close to the primary vibration mode, and significantly improves the sound pressure level amplitude in the vibration output region. Compared with the two-dimensional electrode (the vibration modes are shown in FIGS. 16C and 16D) shown in FIG. 14C, mode control can also be realized using the two-dimensional electrode 130 shown in FIG. 17B.

[0150] In some embodiments, the distributed electrode units have the problem that it is difficult to make circuit connections between the electrodes, and the difficulty of mass production is great. Therefore, the electrodes can be changed from a distributed type to a connected type, which is useful for the manufacture of printing screens and the connection of electrodes and is suitable for mass production. For example, the electrode 130 may include continuously distributed electrodes 135 two-dimensionally, and the continuous electrodes may include a plurality of embossed regions 136.

[0151] In some embodiments, the continuous electrode 135 may be configured as a continuous conductive material provided on the surface of the piezoelectric component 120, and the embossed region 136 may be configured as a region where no conductive material is provided. Compared with the plurality of distributed electrode units 134 shown in FIGS. 14A to 14D or FIG. 17B above, the continuous electrode 135 may be understood as an electrode 130 that integrally connects the electrodes distributed dispersedly, and by providing a plurality of embossed regions 136 to disperse the continuous electrode 135 into a plurality of regions distributed two-dimensionally, the design of the electrode 130 is realized.

[0152] FIG. 19A is a schematic configuration diagram of a part of an exemplary two-dimensionally distributed continuous electrode 130 according to some embodiments of the present specification, FIG. 19B is a schematic configuration diagram of a part of an exemplary two-dimensionally distributed continuous electrode 130 according to some embodiments of the present specification, and FIG. 19C is a schematic configuration diagram of a part of an exemplary two-dimensionally distributed continuous electrode 130 according to some embodiments of the present specification.

[0153] As shown in FIGS. 19A to 19C, the two-dimensional electrode 130 (quarter two-dimensional electrode) may include a continuously distributed electrode 135 in two dimensions, and the continuously distributed electrode 135 may include a plurality of embossed regions 136.

[0154] In some embodiments, the shape of the embossed region 136 may be the same as or different from the shape of the piezoelectric component 120. In some embodiments, the shape of the embossed region 136 may include one or any combination of circular, triangular, square, pentagonal, hexagonal, or irregular shapes. For example, the continuously distributed electrode 135 shown in FIG. 19A may include a plurality of square embossed regions 136, the continuously distributed electrode 135 shown in FIG. 19B may include a plurality of hexagonal embossed regions 136, and the continuously distributed electrode 135 shown in FIG. 19C may include a plurality of square embossed regions and a plurality of octagonal embossed regions.

[0155] In some embodiments, the distance between two adjacent embossed regions 136 at the center of the piezoelectric layer 122 may be greater than the distance between two adjacent embossed regions 136 at the boundary of the piezoelectric layer. Exemplarily, as shown in FIGS. 19A to 19C, the closer to the boundary, the smaller the distance between two adjacent embossed regions 136.

[0156] In some embodiments, the area of the first embossed region 1361 at the center of the piezoelectric layer 122 is smaller than the area of the second embossed region 1362 at the boundary of the piezoelectric layer. As shown in FIGS. 19A to 19C, the first embossed region 1361 is closer to the center of the piezoelectric layer 122 than the second embossed region 1362, and the area of the first embossed region 1361 is smaller than the area of the second embossed region 1362.

[0157] In some embodiments, the piezoelectric layer 122 may be divided into a plurality of two-dimensionally distributed piezoelectric sub-regions of the same size. Each piezoelectric sub-region may include one embossed region 136, and the embossed region 136 may be located at the center of the piezoelectric sub-region. The continuous electrode 135 in the piezoelectric sub-region may be located at the edge of the piezoelectric sub-region and form an electrode that is continuously connected to the continuous electrode 135 of another piezoelectric sub-region. For example, as shown in FIGS. 19A to 19C, the embossed region 136 may be provided at the center of the piezoelectric sub-region such that the electrodes 130 at the edge of the piezoelectric sub-region are continuous.

[0158] In some embodiments, the size of the area of the embossed region 136 may be related to the vibration displacement amount of the piezoelectric sub-region where the embossed region 136 is located at a specific frequency (for example, the primary peak, the secondary peak). In some embodiments, based on the difference (for example, the vibration displacement ratio) between the vibration displacement amount of the piezoelectric sub-region at a specific frequency (for example, the primary peak, the secondary peak) and the maximum displacement amount of the piezoelectric layer 122, the area of the embossed region 136 in each piezoelectric sub-region can be determined. For example, the greater the difference between the vibration displacement amount and the maximum displacement amount of the piezoelectric layer 122, the larger the area of the embossed region 136. FIG. 20 is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification.

[0159] As shown in FIG. 20, curve 26 is the frequency response curve of the piezoelectric component 120 using the integrated electrode, curve 26 is the frequency response curve of the piezoelectric component 120 coated with the two-dimensional electrode 130 of 32×32 distributed electrode units, and curve 27 is the frequency response curve of the piezoelectric component 120 coated with 32×32 continuous electrodes 130 distributed two-dimensionally. According to curves 26 and 27, there is a certain difference between the mode control effect of the continuously distributed electrodes 130 in two dimensions and the mode control effect of the electrodes 130 composed of the distributed electrode units distributed two-dimensionally. For example, the electrode 130 composed of the distributed electrode units distributed two-dimensionally has the resonance dip at 12128 Hz shifted forward to 7829.4 Hz. The reason for the forward shift of the resonance dip may be related to the embossed shape and density of the electrode 130, but it still shows a certain mode control effect on the piezoelectric component 120.

[0160] In the embodiments of this specification, in the manner that the continuous electrode 135 includes a plurality of embossed regions 136, the coating surface of the two-dimensional electrode 130 changes from a distributed type to a connected type, which is useful for the generation, manufacture, and use of the two-dimensional electrode and is more suitable for mass production.

[0161] It should be understood that, similar to the one-dimensional electrode, in the design of the two-dimensional electrode, the effective area of the electrode coated on the piezoelectric layer can be limited by the shape and area of the piezoelectric region in the piezoelectric layer (for example, a piezoelectric plate or a piezoelectric film). For example, the piezoelectric plate or the piezoelectric 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 is equal to the coated area of the piezoelectric plate or the piezoelectric film on the substrate, and the electrode completely coats the piezoelectric plate or the piezoelectric film (that is, the electrode overlaps with the piezoelectric plate or the piezoelectric film). The pattern of the piezoelectric region may be the design pattern of the two-dimensional electrode shown in any one of FIGS. 14A, 14B, 14C, 14D, 17A, 17B, 19A, 19B, or 19C, and the portion other than the piezoelectric region on the substrate is a non-piezoelectric region. Therefore, in the design of the two-dimensional electrode, by making the area of the piezoelectric region < the coated area of the piezoelectric layer (for example, a piezoelectric plate or a piezoelectric film) = the coated area of the electrode ≤ the surface area of the substrate coated by the piezoelectric layer, the mode control of the piezoelectric component can be realized.

[0162] In some embodiments, the electrode 130 may coat one surface of the piezoelectric layer 122 or may coat two surfaces of the piezoelectric layer. For example, the electrode 130 may coat the other surface opposite to the above surface, and the coated area of the electrode 130 on the other surface may be less than or equal to the area of the surface. That is, by realizing the design of the electrode 130 on the two opposite surfaces, the mode of the piezoelectric component 120 can be controlled. Regarding the design of the electrode 130 on the other surface, reference can be made to the design of the electrode 130 in any one of FIGS. 5A, 5C, 8A-8D, 11A, 11B, 14A-14D, 17B, 19A-19C, so the description is omitted here.

[0163] In some embodiments, the piezoelectric component 120 may further include a vibration adjustment component. The vibration adjustment component may be configured as a device that changes the vibration state of the acoustic device (for example, adjusts the output vibration mode by changing the mass, elasticity, or attenuation of one or more components of the acoustic device). In some embodiments, the vibration adjustment component may be connected to the vibration output region 123 of the piezoelectric component 120 and adjust the vibration output from the piezoelectric component 120. In some embodiments, the vibration adjustment component may include one type or any combination thereof, such as a connection member (for example, a housing, etc.), a mass block (for example, a metal mass block, etc.), an elastic member (for example, a traction rope, a spring piece, etc.). The connection member can connect the piezoelectric component 120 to other components, and the elastic member can change the vibration state of the piezoelectric component 120 by supplying elasticity to the piezoelectric component 120.

[0164] In some embodiments, the vibration adjustment component may include a mass block 170, and the mass block is physically (for example, mechanically or electromagnetically) connected to the vibration output region 123. In some embodiments, the mass block 170 may be a component having a certain mass. In some embodiments, the mass block 170 may include one type or any combination thereof, such as a metal mass block, a rubber mass block, a plastic mass block, etc. In some embodiments, the mass block 170 can change the mode of the piezoelectric component 120.

[0165] In some embodiments, the acoustic device 100 may further include a connection member 171 that connects the vibration component 110 and the piezoelectric component 120. In some embodiments, the connection member may be configured as a component having a certain rigidity, and the connection member 171 may include one type or any combination of a plurality of types, such as a vibration transmission sheet, an elastic member, etc. In some embodiments, the mass block 170 may be connected to the vibration output region 123 by the connection member 171.

[0166] Hereinafter, taking the piezoelectric component 120 shown in FIG. 3 above as an example, an exemplary acoustic device is provided, and specific implementation manners of the piezoelectric cantilever beam, the mass block 170, and the connecting member 171 will be described in detail.

[0167] FIG. 21 is a schematic configuration diagram of an exemplary acoustic device according to some embodiments of the present specification. In some embodiments, the acoustic device may include at least one piezoelectric component 120, the vibration output region of each piezoelectric component 120 may be connected to the vibration component 110, and each vibration component 110 is connected to a vibration adjusting component (for example, the mass block 170). As shown in FIG. 21, the acoustic device may include two piezoelectric components 120 coated with the primary electrode 130-1. The vibration output region of each piezoelectric component 120 is connected to the vibration component 110, and the vibration component 110 and the vibration adjusting component (for example, the mass block 170) are connected by at least one connecting member 171.

[0168] In some embodiments, in order to reduce the mode of the piezoelectric component 120, the length of the piezoelectric component 120 of the acoustic device may be shortened. For example, the acoustic device uses the elasticity supplied by the connecting member 171 and the mass block 170 to form a low-frequency peak, thereby reducing the mode using a short piezoelectric cantilever beam (the piezoelectric component 120 shown in FIG. 21), and a flat frequency response curve can be formed between the low-frequency peak of the frequency response curve and the primary mode peak (with a high frequency).

[0169] FIG. 22 is a schematic diagram comparing the frequency response curves of exemplary piezoelectric components according to some embodiments of the present specification.

[0170] As shown in FIG. 22, curve 29 is the frequency response curve of the piezoelectric component 120 using a monolithic electrode with a length of 8 mm, curve 30 is the frequency response curve of the piezoelectric component 120 using the primary electrode 130-1 with a length of 8 mm, curve 31 is the frequency response curve of the piezoelectric component 120 using the primary electrode 130-1 with a length of 10 mm, and curve 32 is the frequency response curve of the piezoelectric component 120 using the primary electrode 130-1 with a length of 12 mm.

[0171] As shown in FIG. 22, for the frequency response curve corresponding to the piezoelectric component 120 shown by curve 29, a secondary resonance occurs at the secondary mode dip (for example, 12272 Hz), which reflects that in the acoustic device, the piezoelectric component 120 using the integral electrode cannot effectively output vibration, so a resonance dip appears in its frequency response curve. The resonance dips of the frequency response curves corresponding to the piezoelectric components 120 shown by curves 30 to 32 become higher and do not affect the vibration characteristics between the resonance dips, which can reflect that by using the design of the primary electrode 130-1 in the acoustic device, the secondary resonance dip generated by the piezoelectric component 120 can be made higher.

[0172] And in the frequency response curves corresponding to the piezoelectric components 120 shown by curves 30 to 32, the mode formed by the piezoelectric cantilever beam (i.e., the piezoelectric component 120) and the vibration transmission sheet moves forward, which reflects that when using the design of the primary electrode 130-1 in the acoustic device, by appropriately increasing the length of the piezoelectric component 120 (for example, making the length of the piezoelectric component 120 8 mm or more, 10 mm or more, or 12 mm or more), the resonance dip can be made higher and the sensitivity of the acoustic device at low frequencies can be improved.

[0173] FIG. 23A is a vibration mode diagram of an acoustic device using an integral electrode according to some embodiments of the present specification, and FIG. 23B is a vibration mode diagram of an acoustic device using a primary electrode 130-1 according to some embodiments of the present specification.

[0174] As shown in FIG. 23A, at the resonance dip (for example, 12272 Hz), a node is formed in the vibration output region of the piezoelectric component 120 of the acoustic device using the integral electrode. As shown in FIG. 23B, at the resonance dip (for example, 12272 Hz), no node is formed in the vibration output region of the piezoelectric component 120 of the acoustic device using the primary electrode 130-1, and it exhibits a primary vibration mode.

[0175] In the embodiments according to this specification, through the design of the electrode 130, the secondary resonance dip in the frequency response curve corresponding to the piezoelectric component 120 of the acoustic device can be raised, and the sensitivity of the acoustic device at low frequencies can be improved using a longer piezoelectric component 120.

[0176] FIG. 24 is a schematic configuration diagram of an exemplary acoustic device according to some embodiments of this specification.

[0177] In some embodiments, as shown in FIG. 24, the acoustic device 100 may have a piezoelectric cantilever output structure. One end of the piezoelectric cantilever (i.e., the piezoelectric component 120) with the designed electrode is the fixed region 124, the other end is the vibration output region 123, and the vibration is output to the diaphragm or the vibrating membrane (i.e., the vibrating component 110) by the connecting member 171. In some embodiments, the acoustic device 100 may be a bone conduction audio device (e.g., bone conduction earphone, bone conduction glasses, etc.). In some embodiments, the fixed end of the piezoelectric component 120 may include one or any combination of a housing of the bone conduction audio device, an earhook apex, a connection part between the earhook and the main body, a glasses temple, etc. In some embodiments, the connecting member 171 has a certain rigidity and may be rigidly connected to the diaphragm or the vibrating membrane and the vibration output region of the piezoelectric cantilever.

[0178] The beneficial effects according to the embodiments of this specification include, but are not limited to, the following (1) to (2). (1) By designing the electrode as a mode actuator of the piezoelectric component, the piezoelectric component generates only the excitation force of a specific mode and outputs the vibration form of the specific mode, avoiding the formation of nodes at the vibration output point of the piezoelectric component, and improving the operation reliability of the acoustic device. (2) Compared with adding a mode control system composed of mechanical structures such as springs, masses, and damping elements to a specific region, the embodiments of this specification can realize the mode control of the piezoelectric component through the design of the electrode and simplify the structure of the acoustic device.

[0179] Although the basic concepts have been described above, it will be apparent to those skilled in the art that the above detailed disclosure is presented merely as an example and is not intended to limit the present specification. Although not explicitly described in this specification, those skilled in the art can make various changes, improvements, and modifications to this specification. Since these changes, improvements, and modifications are intended to be suggested by this specification, they are within the spirit and scope of the exemplary embodiments of this specification.

[0180] Furthermore, specific terms are used in this specification to describe the embodiments herein. For example, "one embodiment", "an embodiment", and / or "some embodiments" mean specific features, structures, or characteristics related to at least one embodiment of this specification. Therefore, it should be emphasized and understood that two or more references to "an embodiment" or "one embodiment" or "one alternative embodiment" in various parts of this specification do not necessarily all refer to the same embodiment. Also, specific features, structures, or characteristics in one or more embodiments of this specification may be appropriately combined.

[0181] Also, unless explicitly stated in the claims, the recited order of process elements or sequences, the use of alphanumerics, or the use of other names in this specification does not limit the order of the procedures and methods in this specification. In the above disclosure, various useful embodiments of the invention that are currently considered are described through various examples. However, such details are for illustrative purposes only. The appended claims are not limited to the disclosed embodiments, but rather are intended to cover all modifications and equivalent combinations within the spirit and scope of the embodiments of this specification. For example, the system assembly described above may be implemented by a hardware device, but may also be implemented by a software-only solution, for example, by installing the system described on an existing server or mobile device.

[0182] Similarly, in the foregoing description of the embodiments of this specification, for the purpose of simplifying this specification and facilitating the understanding of the embodiments of one or more inventions, it should be understood that various features may be grouped in one embodiment, drawing, or its description. However, such a disclosure method should not be construed as reflecting an intention that the claimed subject matter requires more features than those recited in each claim. In fact, the features of an embodiment may be less than all the features of the single embodiment disclosed above.

[0183] In some embodiments, numbers are used to describe the number of components and attributes, and it should be understood that the numbers for describing such embodiments are modified by the modifier "about", "substantially", or "essentially" in some examples. Unless otherwise specified, "about", "substantially", or "essentially" indicates that the above numbers are allowed a variation of ±20%. Thus, in some embodiments, the numerical parameters used in the specification and claims are all approximate values that can vary according to the characteristics required by individual embodiments. In some embodiments, for numerical parameters, the specified number of significant digits should be considered and the normal rounding method should be applied. In some embodiments of this specification, although the numerical ranges and parameters for determining the range are approximate values, in specific embodiments, such numerical values are set as accurately as possible.

[0184] All patents, patent applications, published patent publications, and other materials such as papers, books, specifications, publications, documents, etc., referred to in this specification are incorporated herein by reference in their entirety, except for application process documents that do not match or conflict with the content of this specification, and documents that may have a limiting effect on the broadest scope of the claims of this specification (currently or later related to this specification). In addition, if the descriptions, definitions, and / or uses of terms in the attached materials of this specification do not match or conflict with the content described in this specification, the descriptions, definitions, and / or uses of terms in this specification shall prevail.

[0185] Finally, it should be understood that the examples described in this specification merely explain the principles of the examples in this specification. Other variations may also be within the scope of this specification. Therefore, without limitation, by way of example, alternative configurations of the examples in this specification may be considered to be in accordance with the teachings of this specification. Thus, the examples in this specification are not limited to the examples clearly introduced and described in this specification.

Description of Reference Numerals

[0186] 100 Acoustic device 110 Vibration component 120 Piezoelectric component 130 Electrode 130-1 Primary electrode 130-2 Secondary electrode 123 Vibration output region 121 Substrate 122 Piezoelectric layer 124 Fixed region 131 First electrode envelope region 132 Second electrode envelope region 133 Point 1221 Piezoelectric region 1222 Non-piezoelectric region 140 Mass block model 141 Second vibration output region 134 Distributed electrode unit 1341 First distributed electrode unit 1342 Second distributed electrode unit 1343 Third distributed electrode unit 1344 Fourth distributed electrode unit 171 Connecting member 172 Second shape 135 Continuous electrode 136 Embossed region 1361 First embossed region 1362 Second embossed region 170 Mass block

Claims

1. 1. An audio device, comprising: A piezoelectric component that vibrates under the action of a driving voltage; an electrode for supplying the driving voltage to the piezoelectric component; a vibration component physically connected to the piezoelectric component for receiving the vibration and generating sound; Including, The piezoelectric component includes a vibration output region and a fixing region. An acoustic device, characterized in that the width of the electrodes gradually decreases from the fixed region to the vibration output region along the longitudinal direction of the piezoelectric component.

2. 2. The acoustic device of claim 1, wherein the electrodes have a triangular shape.

3. The piezoelectric component is A substrate; A piezoelectric layer; Including, 2. The acoustic device according to claim 1, wherein the piezoelectric layer covers a surface of the substrate, and the electrode covers a surface of the piezoelectric layer.

4. 4. The acoustic device of claim 3, wherein the coverage area of ​​the electrodes on the piezoelectric layer is smaller than the surface area of ​​the covered piezoelectric layer on the surface of the substrate.

5. 5. The acoustic device according to claim 4, wherein the coverage area of ​​said piezoelectric layer on said substrate is the entire surface area of ​​one surface of said substrate.

6. the piezoelectric layer includes a piezoelectric region formed from a piezoelectric material and a non-piezoelectric region formed from a non-piezoelectric material; 4. The acoustic device of claim 3, wherein the area of ​​the piezoelectric layer is equal to the sum of the areas of the piezoelectric regions and the non-piezoelectric regions.

7. the coverage of the electrodes on the piezoelectric layer is equal to the coverage of the piezoelectric regions covered on the surface of the substrate; a coverage area of ​​the coated piezoelectric regions on a surface of the substrate is smaller than a coverage area of ​​the coated piezoelectric layers on a surface of the substrate; 7. The acoustic device of claim 6, wherein a coverage area of ​​the piezoelectric layer coated on the surface of the substrate is equal to a surface area of ​​the substrate covering the piezoelectric layer.

8. the coverage area of ​​the electrodes on the piezoelectric layer is equal to the coverage area of ​​the coated piezoelectric layer on the surface of the substrate; 4. The acoustic device according to claim 3, wherein the covering area of ​​the electrodes and the covering area of ​​the piezoelectric layer are smaller than a surface area of ​​the substrate covering the piezoelectric layer.

9. the coverage area of ​​the electrodes on the piezoelectric layer is equal to the coverage area of ​​the coated piezoelectric layer on the surface of the substrate; 4. The acoustic device of claim 3, wherein a coverage area of ​​the piezoelectric layer coated on the surface of the substrate is equal to a surface area of ​​the substrate covering the piezoelectric layer.

10. a coverage area of ​​the piezoelectric region on a surface of the substrate is smaller than a coverage area of ​​the piezoelectric layer on a surface of the substrate; 7. The acoustic device of claim 6, wherein the coverage area of ​​the piezoelectric layer on the surface of the substrate is equal to the surface area of ​​the electrodes on the piezoelectric layer and the surface area of ​​the substrate covering the piezoelectric layer.

11. the electrode is also coated on a second surface opposite the surface of the piezoelectric layer; 4. An acoustic device according to claim 3, wherein the coverage area of ​​said electrode on said second surface is less than or equal to the area of ​​said surface.

12. The acoustic device according to claim 3 , wherein the piezoelectric component further includes a vibration adjusting component.

13. 13. The acoustic device of claim 12, wherein the vibration tuning component comprises a mass block physically connected to the vibration output area.

14. the width of the electrode at the fixed region is equal to the width of the fixed region; and 2. The acoustic device according to claim 1, wherein the width of the electrode in the vibration output area is zero.

15. The acoustic device according to claim 1 , further comprising a connector that connects the vibration component and the piezoelectric component.

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