Sound apparatus

Abstract

To provide a sound apparatus in which sound quality is enhanced.SOLUTION: A sound apparatus includes: a first vibration member having a plate shape; a first vibration device which includes a rectangular first main surface and a rectangular second main surface opposite to each other, the first main surface being in contact with the first vibration member, and which vibrates based on a driving signal input thereto; a second vibration member which includes a rectangular first main surface and a rectangular second main surface opposite to each other, a portion of the first main surface of the second vibration member being connected to the first vibration member and a portion of the second main surface of the first vibration device by an elastic member; and a second vibration device which includes a rectangular first main surface and a rectangular second main surface opposite to each other, the first main surface of the second vibration device being in contact with the second main surface of the second vibration member, and which vibrates based on a driving signal input thereto. The first vibration device may be disposed in a direction in which rotation has been performed by a predetermined angle around an axis perpendicular to the first main surface and the second main surface of the second vibration device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an audio device. [Background technology]

[0002] An audio device has a vibration system that converts an input electrical signal into physical vibration. Piezoelectric speakers, which are made of piezoelectric elements such as ferroelectric ceramics, have the advantages of being lightweight and consuming low power, and are therefore used for a variety of purposes. Summary of the Invention [Problem to be solved by the invention]

[0003] The piezoelectric elements used in piezoelectric speakers have a limited vibration range (or displacement range), and therefore may not provide sufficient sound quality.

[0004] The present specification has been made in consideration of the above-mentioned problems, and the inventor of the present specification has conducted several experiments in order to realize an audio device capable of improving sound quality. Through several experiments, the inventor has invented a new audio device capable of improving sound quality. The present specification aims to improve the sound quality of an audio device. [Means for solving the problem]

[0005] According to one aspect of the present specification, there is provided an acoustic device comprising: a first vibration member having a flat plate shape; a first vibration element including rectangular first and second main surfaces facing each other, the first main surface being in contact with the first vibration member, and vibrating in response to an input drive signal; a second vibration member including rectangular first and second main surfaces facing each other, wherein a portion of the first main surface of the second vibration member is connected to a portion of the second main surface of the first vibration member and the first vibration element via an elastic member; and a second vibration element including rectangular first and second main surfaces facing each other, wherein the first main surface of the second vibration element is in contact with the second main surface of the second vibration member, and vibrating in response to an input drive signal, wherein the first vibration element is arranged in a direction rotated at a predetermined angle around an axis perpendicular to the first main surface of the second vibration element and the second main surface of the second vibration element. Effect of the Invention

[0006] According to the present specification, it is possible to improve the sound quality of an audio device. According to the present specification, it is possible to improve the sound pressure characteristics and / or acoustic characteristics in the bass range of an audio device.

[0007] Both the foregoing description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the disclosure as set forth in the appended claims.

[0008] The accompanying drawings, which are included to provide a further understanding of the specification and are incorporated in and constitute a part of the specification, illustrate aspects and implementations of the specification and, together with the description, may serve to explain the principles of the specification. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing the configuration of an audio device and a host system according to a first embodiment of the present specification. [Diagram 2] 1 is a perspective view showing a configuration of an audio device according to a first embodiment of the present specification. [Diagram 3] 1 is a plan view showing a configuration of an acoustic device according to a first embodiment of the present specification. [Figure 4] 1 is a cross-sectional view showing a configuration of an acoustic device according to a first embodiment of the present specification. [Diagram 5] 1 is a cross-sectional view showing a configuration of an acoustic device according to a first embodiment of the present specification. [Figure 6] 1 is a cross-sectional view showing a configuration of an acoustic device according to a first embodiment of the present specification. [Figure 7] 1 is a cross-sectional view showing in more detail the structure of an acoustic device according to a first embodiment of the present specification. [Figure 8] 4 is a graph showing acoustic characteristics of the audio device according to the first embodiment of the present specification. [Figure 9] 4 is a graph showing acoustic characteristics of the audio device according to the first embodiment of the present specification. [Figure 10] FIG. 11 is a cross-sectional view showing the configuration of an acoustic device according to a second embodiment of the present specification. [Figure 11] FIG. 11 is a perspective view showing a configuration of an audio device according to a third embodiment of the present specification. [Figure 12] FIG. 11 is a plan view showing the configuration of an acoustic device according to a third embodiment of the present specification. [Figure 13] FIG. 11 is a cross-sectional view showing the configuration of an acoustic device according to a third embodiment of the present specification. [Figure 14] FIG. 11 is a cross-sectional view showing the configuration of an acoustic device according to a third embodiment of the present specification. [Figure 15] FIG. 11 is a cross-sectional view showing the configuration of an acoustic device according to a third embodiment of the present specification. [Figure 16] FIG. 11 is a cross-sectional view showing in more detail the structure of an acoustic device according to a third embodiment of the present specification. [Figure 17] FIG. 13 is a plan view showing the structure of a vibration element according to a fourth embodiment. [Figure 18] 13 is a cross-sectional view taken along line DD' in FIG. 12 according to the fourth embodiment. [Figure 19] FIG. 13 is a perspective view showing a vibration layer of a vibration element according to a fifth embodiment. [Figure 20] 13 is a perspective view showing a vibration layer of a vibration element according to a sixth embodiment. FIG. [Figure 21] FIG. 13 is a plan view showing the structure of a vibration element according to a seventh embodiment. [Figure 22] 22 is a cross-sectional view taken along line EE' in FIG. 21 according to the seventh embodiment. [Diagram 23] FIG. 13 is a configuration diagram of a display device according to an eighth embodiment of the present specification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Reference will now be made in detail to the embodiments of the present specification, examples of which may be illustrated in the accompanying drawings. In the following description, if a detailed description of a well-known function or configuration unnecessarily obscures the gist of the present specification, the detailed description may be omitted for the sake of brevity. The progression of steps and / or operations described is exemplary, but the order of steps and / or operations is not limited to that described herein and may be modified, except that steps and / or operations necessarily occur in a particular order.

[0011] Unless otherwise specified, the same reference numerals may generally refer to similar components even if they are illustrated in different drawings. In one or more embodiments, the same components (or components having the same name) in different drawings may have the same or substantially the same functions and characteristics, unless otherwise specified. The names of the respective components used in the following description are selected for convenience and may differ from the actual products.

[0012] The advantages and features of the present specification and methods for achieving them will become apparent from various examples described below in detail with reference to the accompanying drawings. However, the present specification is not limited to the embodiment disclosed below, and may be realized in various different forms, and the embodiment etc. of the present specification are provided only to complete the disclosure of the present specification and to fully inform those skilled in the art of the technical idea of ​​the present specification of the scope of the technical idea.

[0013] The shapes, sizes, areas, ratios, angles, numbers, etc. disclosed in the drawings for explaining an embodiment of this specification are merely illustrative, and the present specification is not limited to the details shown in the drawings.

[0014] When the terms "comprise", "have", "consist", "comprise", "formed", etc. are used in this specification, other parts can be added unless "only" or "only" is used. The terms used in this specification are used only to describe a particular embodiment and are not intended to limit the scope of the specification. The terms used in this specification are used only to describe an exemplary embodiment and are not intended to limit the scope of the specification. Terms expressing elements in the singular include the plural unless otherwise expressly stated. An "embodiment" may be an illustrative example. Any implementation described in the "embodiment" or "example" described in this specification should not necessarily be construed as preferred or advantageous over other implementations.

[0015] In one or more embodiments, components, features, or corresponding information (e.g., levels, ranges, dimensions, sizes, etc.) may be interpreted as including an error or tolerance range even if an explicit description of these error or tolerance ranges is not provided. The error or tolerance range may be caused by various factors (e.g., process factors, internal or external impacts, noise, etc.).

[0016] In the case of a description of a location relationship, when a location relationship is described between two parts using words such as "on or over," "on top," "under or below," "at the bottom," "near," "adjacent to," "beside," or "next to," one or more other parts may be located between the two parts, unless "just," "immediately(ly)," "close(ly)," or "direct(ly)" is used. For example, when structures are described as being located "above or over," "on top," "under or below," "on bottom," "near," "adjacent to," "beside," or "next to," this description must be interpreted to include cases where the structures touch each other and have a third structure disposed between them. For example, when structures are described as being located "above or over," "on top," "under or below," "on bottom," "near," "adjacent to," "beside," or "next to," this description must be interpreted to include cases where the structures touch each other and have a third structure disposed between them. Additionally, "front", "back", "back", "left", "right", "top", "bottom", "downward", "upward", "top", "bottom", "column", "row", "vertical", "horizontal", etc. refer to any frame of reference.

[0017] In the case of descriptions of temporal relationships, when the temporal sequence is described using "after," "subsequent," "next," "before, preceding, or prior to," etc., consecutive or non-consecutive cases can also be included, since "just," "immediately," or "directly" are not used.

[0018] Although the terms "first", "second", etc. are used to describe various components, these components are not limited to these terms. These terms are used only to distinguish one component from another component. Thus, a first component referred to below may also be a second component within the technical spirit of this specification. Furthermore, the first element, the second element, etc. may be named arbitrarily according to the convenience of a person skilled in the art without departing from the scope of this specification. Terms such as "first", "second", etc. may be used to distinguish components from each other, but the function or structure of the component is not limited by the ordinal number before the component or the name of the component.

[0019] In describing components of this specification, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are used to distinguish the components from other components, and are not used to define the nature, basis, order, or number of the components.

[0020] When a component or layer is described as being "connected," "bonded," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other components, but that other components or layers may be "disposed" or "interpodated" between each component that may be indirectly connected or connected unless specifically and explicitly stated.

[0021] When a component or layer is described as being in "contact with" or "overlapping" another component or layer, it should be understood that the component may be in direct contact with or overlaid on the other component or layer, but one or more other components or layers may be "disposed" or "interpodded" between each component or layer that may be in indirect contact or overlaid unless otherwise expressly described. For example, for purposes of this specification, terms such as "overlap" and "overlapping" should be understood as "overlapping, electrically and / or physically connected" by, for example, surface-to-surface connection, and "overlapping, electrically and / or physically connected" by, for example, surface-to-surface connection.

[0022] Terms such as "line" or "direction" should not be construed solely in terms of a geometric relationship in which the respective lines or directions are aligned or perpendicular to one another, but can refer to lines or directions that have a broader orientation within which the components of this specification can functionally operate.

[0023] The term "at least one" should be understood to include all possible combinations of one or more of the associated items. For example, the meaning of "at least one of the first, second, and third items" may include only any combination of the first, second, and third items, and not just combinations of items presented from two or more of the first, second, or third items.

[0024] The phrase "first component", "second component" and / or "third component" should be understood as one of the first, second and third components or any or all combinations of the first, second and third components. For example, A, B and / or C can be considered as A only, B only, C only, any or some combination of A, B and C, or all of A, B and C. Furthermore, the phrase "component A / component B" should be understood as component A and / or component B.

[0025] In one or more embodiments, the terms "between" and "in" may be used interchangeably for convenience only, unless otherwise specified. For example, the phrase "between multiple components" may also be understood as "among multiple components." In other embodiments, the phrase "among multiple components" may also be understood as "between multiple components." In one or more embodiments, the number of components may be two. In one or more embodiments, the number of components may be more than two.

[0026] In one or more embodiments, the term "different from each other" may be understood to mean that any component is different from the other component.

[0027] In one or more embodiments, the terms "one or more of" and "one or more of" may be used interchangeably for convenience only, unless otherwise specified. For example, the term "one or more of" can also be understood as "one or more of." For example, the term "one or more of" can also be understood as "one or more of."

[0028] The features of one or more embodiments of the present specification may be combined or combined with each other in part or in whole, and may be technically linked and operated in various ways, and each embodiment may be implemented independently of each other, or may be implemented together in a linked relationship. In one or more embodiments, the components of each device according to various embodiments of the present specification may be operably coupled or configured.

[0029] The terms used in this specification (including technical and scientific terms) may have the same meaning as that understood by a person having ordinary knowledge in the technical field to which this specification belongs. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology, and should not be interpreted as idealized or overly formal unless otherwise specified.

[0030] Hereinafter, the embodiments according to the present specification will be described in detail with reference to the drawings. Elements having common functions throughout the drawings are given the same reference numerals, and duplicated descriptions may be omitted or simplified. Furthermore, for convenience of explanation, the scales, dimensions, sizes, and thicknesses of the components shown in the drawings may have different scales, dimensions, sizes, and thicknesses from the actual scales, dimensions, sizes, and thicknesses, and therefore are not limited to the scales, dimensions, sizes, and thicknesses shown in the drawings.

[0031] [First embodiment] Fig. 1 is a block diagram showing the configuration of an audio device 1 according to this embodiment. A drive signal (or an audio signal) input to the audio device 1 can be described with reference to Fig. 1. The audio device 1 may be used independently as a speaker, or may be built into an advertising billboard, a poster, a guide board, a display device, etc. The use of the audio device 1 of this embodiment is not particularly limited.

[0032] The acoustic device 1 may have a first vibration element 11 and a second vibration element 21. The first vibration element 11 and the second vibration element 21 may be piezoelectric elements that are displaced by the inverse piezoelectric effect when a voltage based on an input drive signal is applied. The first vibration element 11 and the second vibration element 21 may be elements that are displaced by bending in response to a voltage, such as a bimorph, a unimorph, or a multimorph. Since the input drive signal is usually an AC voltage, the first vibration element 11 and the second vibration element 21 can vibrate in response to the input drive signal and generate sound. For example, the first vibration element 11 and the second vibration element 21 may be a vibration generating element, a sound generating element, a piezoelectric element, a vibration generator, a sound generator, a piezoelectric speaker, or a sound generating element.

[0033] The host system 7 is a device or a system including multiple devices that controls the audio device 1 by supplying a drive signal. However, the host system 7 may also supply other signals, such as image signals (e.g., RGB data or RGBW data), timing signals (e.g., vertical synchronization signal, horizontal synchronization signal, data enable signal, etc.), depending on the application of the audio device 1. The host system 7 may be, for example, a sound source playback device, a public address device, a radio broadcast playback system, a television system, a set-top box, a navigation system, an optical disc player, a computer, a home theater system, a video telephone system, etc. The audio device 1 and the host system 7 may be an integrated device or separate devices.

[0034] The host system 7 may include an input unit 701, a D / A (Digital / Analog) converter 711, a PWM (Pulse Width Modulation) circuit 712, transistors 721 and 722, a coil 723, and a capacitor 724. The input unit 701 may input a digital signal for controlling the first vibration element 11 and the second vibration element 21. The D / A converter 711 may convert the digital signal input from the input unit 701 into an analog signal. The PWM circuit 712 may pulse-width modulate the analog signal input from the D / A converter 711 and output a pulse signal. The PNP-type transistor 721 and the NPN-type transistor 722 may form a push-pull circuit. For example, the collector terminals of the transistors 721 and 722 may be connected to each other, and the base terminals of the transistors 721 and 722 may be connected to each other. A positive voltage +Vdd may be applied to the emitter terminal of the transistor 721, and a negative voltage -Vdd may be applied to the emitter terminal of the transistor 722. A pulse signal is applied to the base terminals of the transistors 721 and 722 from the PWM circuit 712, and the transistors 721 and 722 may be driven to be complementarily turned on or off in response to the pulse signal. For example, when a positive pulse signal is applied to the base terminals of the transistors 721 and 722, the transistor 721 is turned on and the transistor 722 is turned off. Therefore, the voltages of the collector terminals of the transistors 721 and 722 are voltage +Vdd. On the other hand, when a negative pulse signal is applied to the base terminals of the transistors 721 and 722, the transistor 721 is turned off and the transistor 722 is turned on. Therefore, the voltages of the collector terminals of the transistors 721 and 722 are voltage -Vdd. Furthermore, when the potential of the pulse signal becomes the ground potential, both the transistors 721 and 722 are turned off. The coil 723 and the capacitor 724 function as a low-pass filter, and can smooth the pulse signals at the collector terminals of the transistors 721 and 722 and output them to the first vibration element 11 and the second vibration element 21 as a drive signal (or an audio signal).

[0035] FIG. 2 is a perspective view showing the configuration of the acoustic device according to this embodiment. FIG. 3 is a plan view showing the configuration of the acoustic device according to this embodiment. FIGS. 4 to 6 are cross-sectional views showing the configuration of the acoustic device according to this embodiment. FIG. 7 is a cross-sectional view showing the structure of the vibration element according to this embodiment in more detail. FIGS. 4 and 7 show cross-sectional views taken along line A-A' in FIG. 3. FIG. 5 shows a cross-sectional view taken along line B-B' in FIG. 3. FIG. 6 shows a cross-sectional view taken along line C-C' in FIG. 3. The specific configuration of the acoustic device 1 according to this embodiment can be described with mutual reference to FIGS. 2 to 7.

[0036] As shown in FIG. 2, the acoustic device 1 may include a first vibration element 11, a second vibration element 21, elastic members 41, 51, a first vibration member 91, and a second vibration member 92. As shown in FIG. 2 and FIG. 3, the first vibration element 11, the second vibration element 21, the first vibration member 91, and the second vibration member 92 have a rectangular or substantially square flat plate shape in a plan view. For example, the outer edges of the first vibration element 11, the second vibration element 21, the first vibration member 91, and the second vibration member 92 are rectangular or substantially square in a plan view. As shown in FIG. 3, the first vibration element 11 may include four corners 11c. Also, the second vibration member 92 may include four corners 92c. The first vibration element 11 and the second vibration element 21 may have the same shape. Also, the first vibration element 11 and the second vibration element 21 may include one or more piezoelectric elements. 2 to 7, coordinate axes are shown in which the direction parallel to the B-B' line and the C-C' line is the x-axis, the direction parallel to the A-A' line is the y-axis, and the direction perpendicular to the x-axis and the y-axis is the z-axis. The direction parallel to the x-axis is called the first direction, and the direction parallel to the y-axis is called the second direction. In this embodiment, the first direction and the second direction form a right angle in a plan view. The first vibration element 11 has two main surfaces facing each other. Here, of the two main surfaces of the first vibration element 11, the surface on the negative side of the z-axis is called the first main surface 11a, and the surface on the positive side of the z-axis is called the second main surface 11b. Each corner 11c of the first vibration element 11 may include a part of the first main surface 11a and a part of the second main surface 11b. Similarly, the second vibration element 21 and the second vibration member 92 each have two main surfaces facing each other. Of the two main surfaces of the second vibrating element 21, the surface on the negative side of the z axis is referred to as the first main surface 21a, and the surface on the positive side of the z axis is referred to as the second main surface 21b. Moreover, of the two main surfaces of the second vibrating member 92, the surface on the negative side of the z axis is referred to as the first main surface 92a, and the surface on the positive side of the z axis is referred to as the second main surface 92b. Each corner 92c of the second vibrating member 92 may include a part of the first main surface 92a and a part of the second main surface 92b.

[0037] The first vibration element 11 may be disposed on the main surface of the first vibration member 91. Specifically, as shown in FIG. 4 to FIG. 6, the entire first main surface 11a of the first vibration element 11 may be connected to the first vibration member 91. For example, the first vibration element 11 and the first vibration member 91 may be connected to each other via an adhesive member 61 (or an adhesive layer, an adhesive, or a first adhesive member). By connecting the entire first main surface 11a of the first vibration element 11 to the first vibration member 91, the rigidity of the first vibration element 11 can be increased, and the occurrence of cracks in the first vibration element 11 when high sound pressure is input can be suppressed. The vibration generated from the first vibration element 11 by the input drive signal (or audio signal) may be transmitted directly (or via an adhesive member) to the first vibration member 91.

[0038] A second vibrating member 92 may be disposed above the first vibrating element 11. The second vibrating member 92 may overlap the first vibrating member 91 and have a size smaller than that of the first vibrating member 91. The first vibrating element 11 may be between the first vibrating member 91 and the second vibrating member 92 and may be connected to the first vibrating member 91. The second vibrating member 92 may be configured to be connected to the first vibrating element 11 and the first vibrating member 91. Specifically, as shown in FIG. 2 and FIG. 4 to FIG. 6, four elastic members 51 connected to the second main surface 11b may be disposed at the corners 11c of the first vibrating element 11. In addition, the elastic members 51 may be connected to a part of the first main surface 92a of the second vibrating member 92. For example, the second vibrating member 92 may be connected to the first vibrating element 11 via the elastic members 51. On the other hand, the second vibrating member 92 does not directly contact the first vibrating element 11. For example, the first main surface 92a of the second vibrating member 92 can be disposed to face the second main surface 11b of the first vibrating element 11 at a predetermined distance. The predetermined distance between the first main surface 92a of the second vibrating member 92 and the second main surface 11b of the first vibrating element 11 can correspond to the thickness of the elastic member 51 (the height of the elastic member 51 in the z-axis direction).

[0039] The second vibration element 21 may be disposed on the second main surface 92b of the second vibration member 92. Specifically, the entire surface of the first main surface 21a of the second vibration element 21 may be connected to the second main surface 92b of the second vibration member 92. For example, the second vibration element 21 and the second vibration member 92 may be connected to each other via an adhesive member 62 (or an adhesive layer, an adhesive, or a second adhesive member). By connecting the entire surface of the first main surface 21a of the second vibration element 21 to the second vibration member 92, the rigidity of the second vibration element 21 can be increased, and the occurrence of cracks in the second vibration element 21 when high sound pressure is input can be suppressed. The vibration generated from the second vibration element 21 by the input drive signal (or audio signal) may be transmitted directly (or via the adhesive member 62) to the second vibration member 92.

[0040] 2, 4, and 6, four elastic members 41 connected to the first main surface 92a may be disposed at corners 92c of the second vibrating member 92. The elastic members 41 may be connected to a part of the main surface of the first vibrating member 91. For example, the second vibrating member 92 may be connected to the first vibrating member 91 via the elastic members 41.

[0041] In the cross-sectional view of FIG. 4, the end face of the elastic member 41 facing the second direction may be aligned with the end face of the second vibrating member 92 facing the second direction. Similarly, in the cross-sectional views of FIG. 5 and FIG. 6, the end faces of the elastic members 41 and 51 facing the first direction may be aligned with the end face of the second vibrating member 92 facing the first direction. However, the elastic members 41 and 51 may not be disposed at the positions shown in FIG. 4 to FIG. 6. For example, the elastic members 41 and 51 may be disposed such that the end faces of the elastic members 41 and 51 are positioned outside the end faces of the second vibrating member 92. Also, the elastic members 41 and 51 may be disposed such that the end faces of the elastic members 41 and 51 are positioned inside the end faces of the second vibrating member 92. For example, the four elastic members 41 may be interposed between the corners 92c of the first main surface 92a of the second vibrating member 92 and the main surface of the first vibrating member 91. For example, each of the four elastic members 51 may be disposed between two adjacent elastic members 41 of the four elastic members 41. For example, each of the four elastic members 51 may be disposed or coupled between the first main surface 92a of the second vibrating member 92 and the second main surface 11b of the first vibrating element 11, between two adjacent elastic members 41 of the four elastic members 41.

[0042] 3 and 4, the second vibration element 21, the first vibration member 91, and the second vibration member 92 may be arranged such that a pair of two sides facing each other are parallel to the first direction, and another pair of two sides facing each other are parallel to the second direction, in a plan view. Meanwhile, the first vibration element 11 may be arranged in a direction rotated 45 degrees around an axis (z-axis) perpendicular to the first main surface 21a and the second main surface 21b of the second vibration element 21, relative to the second vibration element 21, in a plan view. For example, the first vibration element 11 may be arranged such that two diagonals on the second main surface 11b are parallel to the first direction and the second direction, respectively, in a plan view. Also, in a plan view, the corner portion 11c of the first vibration element 11 may include a portion that does not overlap with the second vibration element 21 and the second vibration member 92. For example, the corner 11c of the first vibration element 11 can protrude to the outside of the second vibration element 21 and the second vibration member 92. For example, in a plan view, the second main surface 11b of the first vibration element 11 can include a portion that does not overlap with the second main surface 21b of the second vibration element 21 and the second main surface 92b of the second vibration member 92. On the other hand, the portion other than the corner 11c of the first vibration element 11 can overlap with a portion of the second vibration member 92 in a plan view. For example, the portion of the second main surface 11b in a plan view, excluding the corner 11c, can overlap with a portion of the second main surface 92b of the second vibration member 92. In addition, at least a portion of the portion other than the corner 11c of the first vibration element 11 can overlap with a portion of the second vibration element 21 in a plan view. For example, at least a portion of the portion of the second main surface 11b in a plan view, excluding the corner 11c, can overlap with a portion of the second main surface 21b of the second vibration element 21. It should be noted that the rotation angle of the first vibration element 11 relative to the second vibration element 21 according to the present disclosure is not limited to 45 degrees, and may be any predetermined angle other than 45 degrees.

[0043] The elastic member 41 may be connected to the first vibration member 91 and the second vibration member 92 via the adhesive members 63 and 64 (or adhesive or adhesive layer). Also, the elastic member 51 may be connected to the first vibration element 11 and the second vibration member 92 via the adhesive members 65 and 66 (or adhesive or adhesive layer). For example, the elastic member 41 may be connected to the first vibration member 91 via the adhesive member 63 (or the third adhesive member) and connected to the second vibration member 92 via the adhesive member 64 (or the fourth adhesive member). For example, the elastic member 51 may be connected to the second main surface 11b of the first vibration element 11 via the adhesive member 65 (or the fifth adhesive member) and connected to the first main surface 92a of the second vibration member 92 via the adhesive member 66 (or the sixth adhesive member). For example, elastic member 41 may be a first elastic member, a first connecting member, or a first coupling member, and elastic member 51 may be a coupling member, a coupling member, a second elastic member, a second connecting member, or a second coupling member, but embodiments herein are not limited thereto.

[0044] The elastic member 41 and the elastic member 51 may be made of a material such as a resin. Polyurethane and polyethylene terephthalate (PET) may be used as the resin constituting the elastic member 41 and the elastic member 51, but the embodiment of the present specification is not limited thereto. At least a part of the elastic member 41 and the elastic member 51 may have a hexahedral shape, but the embodiment of the present specification is not limited thereto. For example, the elastic member 41 and the elastic member 51 may be rectangular in plan view and cross-sectional view. Also, at least a part of the elastic member 41 and the elastic member 51 may have a cylindrical shape or an elliptical cylindrical shape. For example, the elastic member 41 and the elastic member 51 may be circular or elliptical in plan view and rectangular in cross-sectional view. The elastic member 41 may be a transmission member or a vibration transmission member that transmits the vibration generated by the second vibration element 21 based on the input drive signal to the first vibration member 91. Furthermore, the elastic member 51 may be a transmission member or a vibration transmission member that transmits the vibration generated by the second vibration element 21 based on the input drive signal to the first vibration member 91 via the first vibration element 11.

[0045] According to an embodiment of the present specification, one or more of the adhesive members 61 to 66 may include an elastic material that has adhesiveness and can be compressed and restored. For example, the adhesive members 61 to 66 may include an adhesive material having elasticity or stretchability. For example, the adhesive members 61 to 66 may include an adhesive material having a low elastic modulus (or Young's modulus). For example, the adhesive members 61 to 66 may be composed of an adhesive resin, an adhesive, an adhesive tape, an adhesive pad, or the like, but the embodiment of the present specification is not limited thereto. For example, the adhesive tape may include a double-sided tape, a double-sided foam tape, or a double-sided sponge tape, or the like, having an adhesive layer. The adhesive pad may include an elastic pad such as a rubber pad or a silicone pad, having an adhesive layer and capable of being compressed and restored.

[0046] The adhesive resin, adhesive, or adhesive layer of the adhesive members 61 to 66 according to other embodiments of the present specification may include an epoxy-based, acrylic-based, silicone-based, or urethane-based adhesive material, but the embodiments of the present specification are not limited thereto. For example, the adhesive members 61 to 66 may include an acrylic-based adhesive material, which has relatively excellent adhesive strength and high hardness characteristics among acrylic and urethane, so that the vibration of the vibration elements 11 and 21 can be well transmitted to the vibration members 91 and 92, but the embodiments of the present specification are not limited thereto.

[0047] The adhesive resin, adhesive, or adhesive layer of the adhesive members 61 to 66 according to the embodiment of the present specification may be a photocurable adhesive material, but the embodiment of the present specification is not limited thereto. For example, the adhesive resin, adhesive, or adhesive layer may be a UV (ultraviolet) adhesive, but the embodiment of the present specification is not limited thereto.

[0048] The first vibrating member 91 and the second vibrating member 92 may be a manual vibrating member, a vibrating plate, or a vibrating substrate. The first vibrating member 91 and the second vibrating member 92 may have a flat plate shape. The first vibrating member 91 and the second vibrating member 92 may be made of materials such as metal, resin, glass, hard paper, wood, rubber, plastic, fiber, cloth, paper, leather, or carbon. Stainless steel (SUS) may be used as the metal constituting the first vibrating member 91 and the second vibrating member 92, but the embodiment of the present specification is not limited to this. In particular, when a material containing stainless steel is used for the first vibrating member 91 and the second vibrating member 92, the strength of the first vibrating element 11 and the second vibrating element 21 can be increased and the occurrence of cracks can be suppressed. When the applied voltage is increased to a certain level or more in order to increase the sound pressure output from the acoustic device 1, the curvature of the first vibrating element 11 and the second vibrating element 21 increases, which may cause cracks in the vibrating elements. The cracks generated in the vibrating elements significantly deteriorate the acoustic performance. According to the present disclosure, an audio device is provided that suppresses the occurrence of cracks even when high sound pressure is required due to a large signal input and has improved sound quality.

[0049] In addition, the first vibrating member 91 may include a display panel having pixels configured to display an image, a screen panel onto which an image is projected from a display device, a lighting panel, a light emitting diode lighting panel, an organic light emitting lighting panel, an inorganic light emitting lighting panel, a signage panel, an interior material of a vehicle, a glass window of a vehicle, an exterior material of a vehicle, a seat interior material of a vehicle, a ceiling material of a vehicle, a ceiling material of a building, an interior material of a building, a glass window of a building, an interior material of an aircraft, a glass window of an aircraft, or a mirror, but the embodiments herein are not limited thereto.

[0050] An example of the structure of the acoustic device 1 can be described in more detail with reference to Fig. 7. Fig. 7 is an enlarged view of the first vibration element 11 and the second vibration element 21 in the same cross section as Fig. 6. Fig. 7 also shows a schematic circuit diagram of the connection relationship of the electrodes included in the first vibration element 11 and the second vibration element 21 to explain a method of inputting a drive signal to the acoustic device 1.

[0051] The first vibration element 11 may include an electrode 111 (or a first electrode), a vibration layer 112 (or a piezoelectric layer), and an electrode 113 (or a second electrode). The electrode 111 and the electrode 113 may be arranged to sandwich the vibration layer 112 in the thickness direction. A voltage V1 may be applied to the vibration layer 112 via the electrode 111 and the electrode 113. The voltage V1 may correspond to a drive signal (or an audio signal).

[0052] The first vibration element 11 may further include a protective layer 117 (or a protective member). The protective layer 117 may protect and / or insulate the upper surface of the electrode 111. The first vibration element 11 may further include a second protective layer 118 (or a second protective member). The second protective layer 118 may be configured to protect and / or insulate the lower surface of the electrode 113. For example, one or more of the protective layer 117 and the second protective layer 118 may be omitted. For example, the protective layers 117 and 118 may be a polyimide film, a polyethylene terephthalate film, or a polyethylene naphthalate, but the embodiments herein are not limited thereto. In this embodiment, the poling direction of the vibration layer 112 is set to the positive direction of the z-axis as shown in FIG. 7, but may be the negative direction. It should be noted that wiring for applying a voltage to each electrode may be connected to the electrodes 111 and 113 by soldering or the like.

[0053] The first vibration element 11 may be connected to the first vibrating member 91 by an adhesive member 61 (or a first adhesive member). The adhesive member 61 may be configured to connect the first vibration element 11 to a main surface of the first vibrating member 91. For example, the first vibration element 11 may be connected to the main surface of the first vibrating member 91 by a full-surface adhesion method using the adhesive member 61.

[0054] The second vibration element 21 may include an electrode 211 (or a first electrode), a vibration layer 212 (or a piezoelectric layer), and a first electrode 213 (or a second electrode). The electrode 211 and the electrode 213 may be arranged to sandwich the vibration layer 212 in the thickness direction. A voltage V2 may be applied to the vibration layer 212 via the electrode 211 and the electrode 213. The voltage V2 may correspond to a drive signal (or an audio signal). The voltage V2 may have the same phase as the voltage V1 applied to the first vibration element 11, or may have an opposite phase to the voltage V1.

[0055] The second vibration element 21 may further include a protective layer 217 (or a first protective member). The protective layer 217 may protect and / or insulate the upper surface of the electrode 211. The second vibration element 21 may further include a second protective layer 218 (or a second protective member). The second protective layer 218 may protect and / or insulate the lower surface of the electrode 213. One or more of the protective layer 217 and the second protective layer 218 may be optional. For example, one or more of the protective layer 217 and the second protective layer 218 may be optional. For example, the protective layers 217 and 218 may be a polyimide film, a polyethylene terephthalate film, or a polyethylene naphthalate, but the embodiments herein are not limited thereto.

[0056] The second vibration element 21 may be connected to the second vibration member 92 by an adhesive member 62 (or a second adhesive member). The adhesive member 62 may be configured to connect the second vibration element 21 to the second main surface 92b of the first vibration member 92. For example, the second vibration element 21 may be connected to the second main surface 92b of the second vibration member 92 by a full-surface adhesion method using the adhesive member 62. For example, the phases of the input voltages V1 and V2 may be appropriately changed depending on the elastic modulus of the elastic member 41, the elastic member 51, and the second vibration member 92 used in the audio device 1. In this embodiment, the polarization direction of the vibration layer 212 is the positive direction of the z axis as shown in FIG. 7, but may be the negative direction. Wiring for applying a voltage to each electrode may be connected to the electrodes 211 and 213 by soldering or the like.

[0057] The voltages applied to the first vibration element 11 and the second vibration element 21 are based on audio signals, and can be considered as AC voltages corresponding to the frequency of the audio to be generated. In FIG. 7, the AC voltage supplied to the first vibration element 11 is V1, and the AC voltage supplied to the second vibration element 21 is V2. One terminal of the AC power supply may be connected to the electrodes 111 and 211, and the other terminal may be connected to the electrodes 113 and 213. Although two AC power supplies are shown in FIG. 7, one AC power supply may be used. For example, when the voltage V2 has the same phase as the voltage V1 applied to the first vibration element 11, a drive signal may be supplied to the first vibration element 11 and the second vibration element 21 from one (common) AC power supply. For example, one terminal of the common AC power supply may be connected to the electrodes 111 and 211, and the other terminal may be connected to the electrodes 113 and 213. Furthermore, even when the voltage V2 has an opposite phase to the voltage V1 applied to the first vibration element 11, a drive signal may be supplied from one (common) AC power source to the first vibration element 11 and the second vibration element 21. For example, one terminal of the common AC power source may be connected to the electrodes 111 and 213, and the other terminal may be connected to the electrodes 113 and 211.

[0058] When an AC voltage is applied between the electrode 111 and the electrode 113 of the first vibration element 11, the vibration layer 112 expands and contracts, and a periodic stress is applied to the first vibration member 91. For example, the first vibration element 11 transmits a periodic stress to the first vibration member 91, and the first vibration member 91 can bend and vibrate due to the transmitted stress. The vibration of the first vibration member 91 based on the transmitted stress generates a vibration based on an audio signal, for example, a sound. Similarly, when an AC voltage is applied between the electrode 211 and the electrode 213 of the second vibration element 21, the vibration layer 212 expands and contracts, and a periodic stress is applied to the first vibration member 91 via the elastic member 41, the elastic member 51, and the first vibration element 11. The transmitted stress causes the first vibration member 91 to bend and vibrate, and vibration and / or sound based on an audio signal is generated.

[0059] The material of the vibration layer 112 and the vibration layer 212 is not particularly limited, but since it can increase the amount of displacement, a material with good piezoelectricity such as lead zirconate titanate can be used. As another example, the material used for the vibration layer 112 and the vibration layer 212 can include a ceramic-based piezoelectric material that can achieve relatively high vibration. As yet another example, the vibration layer 112 and the vibration layer 212 can include a piezoelectric ceramic material having a crystal structure of the Perovskite series. Also, the vibration layer 112 and the vibration layer 212 can have a polycrystalline structure, but can also have a single crystal structure. For example, the vibration layer 112 and the vibration layer 212 can be made of a polycrystalline ceramic or a single crystal ceramic. Also, the vibration layer 112 and the vibration layer 212 can be made of a PVDF (polyvinylidene fluoride)-based material or a material containing a piezoelectric material containing lead (Pb), but can also be made of a piezoelectric material that does not contain lead. Examples of the piezoelectric material containing lead include one or more of PZT (Lead Zirconate Titanate)-based materials, PZNN (Lead Zirconate Nickel Niobate)-based materials, PMN (Lead Magnesium Niobate)-based materials, PNN (Lead Nickel Niobate)-based materials, PZN (Lead Zirconate Niobate)-based materials, and PIN (Lead Indium Niobate)-based materials. Examples of the piezoelectric material not containing lead include one or more of barium titanate (BaTiO3), calcium titanate (CaTiO3), and strontium titanate (SrTiO3), but the embodiments of the present specification are not limited thereto.

[0060] The adhesive member 61 and the adhesive member 62 may be a pressure-bonding resin material, an adhesive, an adhesive tape, or the like, but the embodiments of the present specification are not limited thereto. The elastic modulus of the adhesive member 61 and the adhesive member 62 may be the same or different from each other. For example, the adhesive member 61 may have a lower elastic modulus than the adhesive member 62. Although not shown in FIG. 7, each side of the first vibration element 11 and the second vibration element 21 may be covered with an insulator such as a resin to avoid shorting with other members.

[0061] The material of the first electrode (111, 211) and the second electrode (113, 213) of the first vibration element 11 and the second vibration element 21 may include a transparent conductive material, a semi-transparent conductive material, or an opaque conductive material. For example, as a transparent or semi-transparent conductive material, the first electrode and the second electrode may include one or more of ITO (indium tin oxide) or IZO (indium zinc oxide), but the embodiment of the present specification is not limited thereto. As an opaque conductive material, the first electrode and the second electrode may include one or more of aluminum (Al), copper (Cu), gold (Au), silver (Ag), molybdenum (Mo), or magnesium (Mg), or an alloy thereof, but the embodiment of the present specification is not limited thereto.

[0062] The improvement in sound quality of the acoustic device according to this embodiment can be explained with reference to actual measurement data. Fig. 8 and Fig. 9 are graphs showing the acoustic characteristics of the acoustic device according to this embodiment. The horizontal axis of Fig. 8 and Fig. 9 is frequency (Hz) on a logarithmic scale, and the vertical axis is sound pressure in decibels (dB). The curve shown by a solid line in Fig. 8 is the acoustic characteristics of the acoustic device 1 of this embodiment when the phase of each drive signal (or audio signal) input to the first vibration element 11 is made the same as the phase of the drive signal input to the second vibration element 21. The curve shown by a solid line in Fig. 9 is the acoustic characteristics of the acoustic device 1 of this embodiment when the phase of each drive signal (or audio signal) input to the first vibration element 11 is made inverse to the phase of the drive signal input to the second vibration element 21. In this measurement, stainless steel with a thickness of 0.3 mm is used as the first vibration member 91 and the second vibration member 92. The curves indicated by dashed dotted lines in Figs. 8 and 9 represent the acoustic characteristics of an acoustic device in which two vibration elements are stacked in a manner different from that of this embodiment (hereinafter referred to as "experimental example").

[0063] The acoustic device 1 of this embodiment can be compared with the experimental example with reference to FIG. 8. The acoustic device 1 of this embodiment shows a higher sound pressure than the experimental example in almost all bands between approximately 25 Hz and 1000 Hz. Moreover, the acoustic device 1 of this embodiment shows a relatively flat acoustic characteristic in a wide frequency band compared to the experimental example. Moreover, in this experiment, no cracks were generated in the first vibration element 11 and the second vibration element 21 of the acoustic device 1. For example, when drive signals of the same phase are input to the first vibration element 11 and the second vibration element 21, the acoustic device 1 according to this embodiment can generate high sound pressure in the low-mid range while suppressing the occurrence of cracks. Therefore, according to the present disclosure, the sound quality of the acoustic device can be further improved.

[0064] Next, the acoustic device 1 of this embodiment can be compared with the experimental example with reference to FIG. 9. The acoustic device 1 of this embodiment shows a higher sound pressure than the experimental example in almost all bands between about 20 Hz and 1000 Hz. Moreover, the acoustic device 1 of this embodiment shows a relatively flat acoustic characteristic in a wide frequency band compared to the experimental example. Moreover, in this experiment, no cracks were generated in the first vibration element 11 and the second vibration element 21 of the acoustic device 1. For example, even when a drive signal having a phase opposite to that of the second vibration element 21 is input to the first vibration element 11, the acoustic device 1 according to this embodiment can generate high sound pressure in the low-mid range while suppressing the generation of cracks. Therefore, according to the present disclosure, the sound quality of the acoustic device can be further improved.

[0065] [Second embodiment] The acoustic device 1 in the second embodiment can be described below. The configurations of the first vibration element 11, the second vibration element 21, the elastic member 41, the elastic member 51, the first vibration member 91, and the second vibration member 92 are the same as those in the first embodiment, so the description can be omitted. The perspective view and the plan view in this embodiment are the same as those in Fig. 2 and Fig. 3. Therefore, the acoustic device 1 in this embodiment can be described with reference to Fig. 2 and Fig. 3.

[0066] Fig. 10 is a cross-sectional view showing the configuration of an acoustic device 1 according to this embodiment. Fig. 10 shows a cross-sectional view taken along line BB' in Fig. 3. As shown in Fig. 10, the acoustic device 1 according to this embodiment differs from the acoustic device 1 according to the first embodiment in that it further includes an elastic member 52. For example, the acoustic device 1 according to this embodiment can include a first vibration element 11, a second vibration element 21, an elastic member 41, an elastic member 51, an elastic member 52, a first vibrating member 91, and a second vibrating member 92.

[0067] As shown in FIG. 10, the elastic member 52 may be disposed on the second main surface 11b of the first vibration element 11. The elastic member 52 may be disposed between the first vibration element 11 and the second vibration member 92. For example, the elastic member 52 may be disposed between the central region of the first vibration element 11 and the central region of the second vibration member 92. Specifically, the elastic member 52 may be disposed in a central region including a point (geometric center) where two diagonals of the second main surface 11b of the first vibration element 11 intersect in a plan view. In addition, the elastic member 52 may be connected to a part of the first main surface 92a of the second vibration member 92. Specifically, the elastic member 52 may be connected to a central region including a point (geometric center) where two diagonals of the first main surface 92a of the second vibration member 92 intersect in a plan view. For example, the second vibration member 92 may be connected to the first vibration element 11 via the elastic member 51 and the elastic member 52. On the other hand, the second vibrating member 92 does not directly contact the first vibrating element 11. For example, the first main surface 92a of the second vibrating member 92 may be disposed to face the second main surface 11b of the first vibrating element 11 at a predetermined distance. The predetermined distance between the first main surface 92a of the second vibrating member 92 and the second main surface 11b of the first vibrating element 11 may correspond to the thickness of the elastic member 52 (the height of the elastic member 52 in the z-axis direction). For example, the elastic member 52 may be connected to the second main surface 11b of the first vibrating element 11 via the adhesive member 67 (or the seventh adhesive member) and connected to the first main surface 92a of the second vibrating member 92 via the adhesive member 68 (or the eighth adhesive member). For example, the elastic member 52 may be a third elastic member, a third connecting member, or a third joining member. According to this embodiment, it is possible to provide an acoustic device 1 that generates high sound pressure in the low-mid range while suppressing the occurrence of cracks, similar to the acoustic device 1 in the first embodiment.

[0068] [Third embodiment] The acoustic device 1 in the third embodiment can be described below. The configurations of the elastic member 41, the elastic member 51 and the first vibrating member 91 are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0069] FIG. 11 is a perspective view showing the configuration of the acoustic device according to this embodiment. FIG. 12 is a plan view showing the configuration of the acoustic device according to this embodiment. FIGS. 13 to 15 are cross-sectional views showing the configuration of the acoustic device according to this embodiment. FIG. 16 is a cross-sectional view showing the structure of the vibration element according to this embodiment in more detail. FIGS. 13 and 16 show cross-sectional views taken along line A-A' in FIG. 12. FIG. 14 shows a cross-sectional view taken along line B-B' in FIG. 12. FIG. 15 shows a cross-sectional view taken along line C-C' in FIG. 12. The specific configuration of the acoustic device 1 according to this embodiment can be described by mutually referring to FIGS. 12 to 16.

[0070] As shown in FIG. 11, the acoustic device 1 in this embodiment may include a first vibration element 11, a second vibration element 21, elastic members 41, 51, a first vibration member 91, and a second vibration member 92. As shown in FIG. 11 and FIG. 12, the first vibration element 11, the second vibration element 21, and the second vibration member 92 may have a rectangular flat plate shape in a plan view. For example, the first main surfaces 11a, 21a, 92a and the second main surfaces 11b, 21b, 92b of the first vibration element 11, the second vibration element 21, and the second vibration member 92 may have short sides and long sides in a plan view. As shown in FIG. 12, the second vibration member 92 may include four corners 92c. The first vibration element 11 and the second vibration element 21 may have the same shape. In addition, the first vibration element 11 and the second vibration element 21 may include one or more piezoelectric elements. 12 to 16 may show coordinate axes in which the direction parallel to the B-B' line and the C-C' line is the x-axis, the direction parallel to the A-A' line is the y-axis, and the direction perpendicular to the x-axis and the y-axis is the z-axis. The direction parallel to the x-axis is called the first direction, and the direction parallel to the y-axis is called the second direction. The first direction and the second direction form a right angle in a plan view. The first vibration element 11 may have two main surfaces facing each other. Of the two main surfaces of the first vibration element 11, the surface on the negative side of the z-axis is called the first main surface 11a, and the surface on the positive side of the z-axis is called the second main surface 11b. Similarly, the second vibration element 21 and the second vibration member 92 may each have two main surfaces facing each other. Of the two main surfaces of the second vibrating element 21, the surface on the negative side of the z axis is referred to as the first main surface 21a, and the surface on the positive side of the z axis is referred to as the second main surface 21b. Moreover, of the two main surfaces of the second vibrating member 92, the surface on the negative side of the z axis is referred to as the first main surface 92a, and the surface on the positive side of the z axis is referred to as the second main surface 92b. Each corner 92c of the second vibrating member 92 may include a part of the first main surface 92a and a part of the second main surface 92b.

[0071] The first vibration element 11 may be disposed on the main surface of the first vibration member 91. Specifically, as shown in FIG. 13 and FIG. 14, the entire surface of the first main surface 11a of the first vibration element 11 may be connected to the first vibration member 91. For example, the first vibration element 11 and the first vibration member 91 may be connected to each other via an adhesive member 61 (or an adhesive layer, an adhesive, or a first adhesive member). By connecting the entire surface of the first main surface 11a of the first vibration element 11 to the first vibration member 91, the rigidity of the first vibration element 11 may be increased, and the occurrence of cracks in the first vibration element 11 when high sound pressure is input may be suppressed. The vibration generated from the first vibration element 11 by the input drive signal (or audio signal) may be directly (or via an adhesive member) transmitted to the first vibration member 91. For example, the entire surface of the first main surface 11a of the first vibration element 11 may be connected to the main surface of the first vibration member 91 by a full-surface adhesion method using the adhesive member 61.

[0072] A second vibrating member 92 may be disposed above the first vibrating element 11. Specifically, as shown in FIG. 11, FIG. 13, and FIG. 14, two elastic members 51 may be disposed on the second main surface 11b of the first vibrating element 11. The elastic members 51 may be connected to a part of the first main surface 92a of the second vibrating member 92. For example, the second vibrating member 92 may be connected to the first vibrating element 11 via the elastic members 51. On the other hand, the second vibrating member 92 does not directly contact the first vibrating element 11. For example, the first main surface 92a of the second vibrating member 92 may be disposed to face the second main surface 11b of the first vibrating element 11 at a predetermined distance. The predetermined distance between the first main surface 92a of the second vibrating member 92 and the second main surface 11b of the first vibrating element 11 may correspond to the thickness of the elastic members 51 (the height of the elastic members 51 in the z-axis direction). For example, the elastic member 51 can be connected to the second main surface 11b of the first vibration element 11 via an adhesive member 65 (or a fifth adhesive member) and connected to the first main surface 92a of the second vibration member 92 via an adhesive member 66 (or a sixth adhesive member).

[0073] The second vibration element 21 may be disposed on the second main surface 92b of the second vibration member 92. Specifically, the entire surface of the first main surface 21a of the second vibration element 21 may be connected to the second main surface 92b of the second vibration member 92. For example, the second vibration element 21 and the second vibration member 92 may be connected to each other via an adhesive member 62 (or an adhesive layer, an adhesive, or a second adhesive member). By connecting the entire surface of the first main surface 21a of the second vibration element 21 to the second vibration member 92, the rigidity of the second vibration element 21 can be increased and the occurrence of cracks in the second vibration element 21 when high sound pressure is input can be suppressed. The vibration generated from the second vibration element 21 by the input drive signal (or audio signal) may be transmitted directly (or via an adhesive member) to the second vibration member 92.

[0074] 11, 13, and 15, four elastic members 41 connected to the first main surface 92a may be disposed at corners 92c of the second vibrating member 92. The elastic members 41 may be connected to parts of the main surface of the first vibrating member 91. For example, the second vibrating member 92 may be coupled to the first vibrating member 91 via the elastic members 41.

[0075] In the cross-sectional view of FIG. 13, the end face of the elastic member 41 facing the second direction may be aligned with the end face of the second vibrating member 92 facing the second direction. In the cross-sectional view of FIG. 14, the end face of the elastic member 51 facing the first direction may be aligned with the end face of the second vibrating member 92 facing the first direction. Similarly, in the cross-sectional view of FIG. 15, the end face of the elastic member 41 facing the first direction may be aligned with the end face of the second vibrating member 92 facing the first direction. However, the elastic members 41 and 51 may not be disposed at the positions shown in FIG. 13 to FIG. 15. For example, the elastic members 41 and 51 may be disposed such that the end faces of the elastic members 41 and 51 are positioned outside the end faces of the second vibrating member 92. In addition, the elastic members 41 and 51 may be disposed such that the end faces of the elastic members 41 and 51 are positioned inside the end faces of the second vibrating member 92. For example, the four elastic members 41 may be interposed between a corner 92c of the first main surface 92a of the second vibrating member 92 and the main surface of the first vibrating member 91. For example, each of the two elastic members 51 may be disposed between two adjacent elastic members 41 along the longitudinal direction of the long side of the second vibrating member 92 among the four elastic members 41. For example, each of the two elastic members 51 may be disposed or connected between the first main surface 92a of the second vibrating member 92 and the second main surface 11b of the first vibrating element 11, between two adjacent elastic members 41 among the four elastic members 41.

[0076] 12, the first vibration element 11 may be arranged such that a pair of long sides facing each other are parallel to the first direction and a pair of short sides facing each other are parallel to the second direction in a plan view. Meanwhile, the second vibration element 21 and the second vibration member 92 may be arranged such that a pair of long sides facing each other are parallel to the second direction and a pair of short sides facing each other are parallel to the first direction in a plan view. For example, the second vibration element 21 and the second vibration member 92 may be arranged such that the long sides of the second main surfaces 21b, 92b of the second vibration element 21 and the second vibration member 92 intersect with the long side of the second main surface 11b of the first vibration element 11 in a plan view. More specifically, the second vibration element 21 and the second vibration member 92 may be arranged such that the long sides of the second main surfaces 21b, 92b of the second vibration element 21 and the second vibration member 92 are perpendicular to the long side of the second main surface 11b of the first vibration element 11 in a plan view. Also, the second vibration element 21 and the second vibration member 92 may be arranged such that the short sides of the second main surfaces 21b, 92b of the second vibration element 21 and the second vibration member 92 are parallel to the long side of the second main surface 11b of the first vibration element 11 in a plan view. For example, the first vibration element 11 according to this embodiment may be arranged in a direction rotated 90 degrees around an axis (z-axis) perpendicular to the first main surface 21a and the second main surface 21b of the second vibration element 21. Therefore, in a plan view, the second main surface 11b of the first vibration element 11 may include a portion that does not overlap with the second main surface 21b of the second vibration element 21 and the second main surface 92b of the second vibrating member 92. Note that the rotation angle of the first vibration element 11 with respect to the second vibration element 21 according to this embodiment is not limited to 90 degrees and can be any angle.

[0077] An example of the structure of the acoustic device 1 can be described in more detail with reference to Fig. 16. Fig. 16 is an enlarged view of the first vibration element 11 and the second vibration element 21 in the same cross section as Fig. 13. Fig. 16 also shows a schematic circuit diagram of the connection relationship of the electrodes included in the first vibration element 11 and the second vibration element 21 to explain a method of inputting a drive signal to the acoustic device 1.

[0078] The first vibration element 11 may include an electrode 111 (or a first electrode), a vibration layer 112 (or a piezoelectric layer), and an electrode 113 (or a second electrode). The electrode 111 and the electrode 113 may be arranged to sandwich the vibration layer 112 in the thickness direction. A voltage V1 may be applied to the vibration layer 112 via the electrode 111 and the electrode 113. The voltage V1 may correspond to a drive signal (or an audio signal).

[0079] The first vibration element 11 may further include a protective layer 117 (or a protective member). The protective layer 117 may protect and / or insulate the upper surface of the electrode 111. The first vibration element 11 may further include a second protective layer 118 (or a second protective member). The second protective layer 118 may be configured to protect and / or insulate the lower surface of the electrode 113. For example, one or more of the protective layer 117 and the second protective layer 118 may be omitted. For example, the protective layers 117 and 118 may be a polyimide film, a polyethylene terephthalate film, or a polyethylene naphthalate film, but the embodiments herein are not limited thereto. In this embodiment, the poling direction of the vibration layer 112 is set to the positive direction of the z-axis as shown in FIG. 16, but may be the negative direction. It should be noted that wiring for applying a voltage to each electrode may be connected to the electrodes 111 and 113 by soldering or the like.

[0080] The first vibration element 11 may be connected to the first vibrating member 91 by an adhesive member 61 (or a first adhesive member). The adhesive member 61 may be configured to connect the first vibration element 11 to a main surface of the first vibrating member 91. For example, the first vibration element 11 may be connected to the main surface of the first vibrating member 91 by a full-surface adhesion method using the adhesive member 61.

[0081] The second vibration element 21 may include an electrode 211 (or a first electrode), a vibration layer 212 (or a piezoelectric layer), and an electrode 213 (or a second electrode). The electrode 211 and the electrode 213 may be arranged to sandwich the vibration layer 212 in the thickness direction. A voltage V2 may be applied to the vibration layer 212 via the electrode 211 and the electrode 213. The voltage V2 may correspond to a drive signal (or an audio signal). The voltage V2 may have the same phase as the voltage V1 applied to the first vibration element 11, or may have an opposite phase to the voltage V1.

[0082] The second vibration element 21 may further include a protective layer 217 (or a first protective member). The protective layer 217 may protect and / or insulate the upper surface of the electrode 211. The second vibration element 21 may further include a second protective layer 218 (or a second protective member). The second protective layer 218 may protect and / or insulate the lower surface of the electrode 213. One or more of the protective layer 217 and the second protective layer 218 may be optional. For example, one or more of the protective layer 217 and the second protective layer 218 may be optional. For example, the protective layers 217 and 218 may be a polyimide film, a polyethylene terephthalate film, or a polyethylene naphthalate, but the embodiments of the present specification are not limited thereto.

[0083] The second vibration element 21 may be connected to the second vibration member 92 by an adhesive member 62 (or a second adhesive member). The adhesive member 62 may be configured to connect the second vibration element 21 to the second main surface 92b of the first vibration member 92. For example, the second vibration element 21 may be connected to the second main surface 92b of the second vibration member 92 by a full-surface adhesion method using the adhesive member 62. For example, the phases of the input voltages V1 and V2 may be appropriately changed depending on the elastic modulus of the elastic member 41, the elastic member 51, and the second vibration member 92 used in the audio device 1. In this embodiment, the polarization direction of the vibration layer 212 is the positive direction of the z axis as shown in FIG. 16, but may be the negative direction. Wiring for applying a voltage to each electrode may be connected to the electrodes 211 and 213 by soldering or the like.

[0084] The voltages applied to the first vibration element 11 and the second vibration element 21 are based on audio signals, and therefore can be considered as AC voltages corresponding to the frequency of the audio to be generated. In FIG. 16, the AC voltage supplied to the first vibration element 11 is V1, and the AC voltage supplied to the second vibration element 21 is V2. One terminal of the AC power supply may be connected to the electrodes 111 and 211, and the other terminal may be connected to the electrodes 113 and 213. Although two AC power supplies are shown in FIG. 16, one AC power supply may be used. For example, when the voltage V2 has the same phase as the voltage V1 applied to the first vibration element 11, a drive signal may be supplied to the first vibration element 11 and the second vibration element 21 from one (common) AC power supply. For example, one terminal of the common AC power supply may be connected to the electrodes 111 and 211, and the other terminal may be connected to the electrodes 113 and 213. Furthermore, even when the voltage V2 has an opposite phase to the voltage V1 applied to the first vibration element 11, a drive signal can be supplied from one (common) AC power source to the first vibration element 11 and the second vibration element 21. For example, one terminal of the common AC power source can be connected to the electrodes 111 and 213, and the other terminal can be connected to the electrodes 113 and 211.

[0085] When an AC voltage is applied between the electrode 111 and the electrode 113 of the first vibration element 11, the vibration layer 112 expands and contracts, and a periodic stress is applied to the first vibration member 91. For example, the first vibration element 11 transmits a periodic stress to the first vibration member 91, and the first vibration member 91 can bend and vibrate due to the transmitted stress. The vibration of the first vibration member 91 based on the transmitted stress generates a vibration based on an audio signal, for example, a sound. Similarly, when an AC voltage is applied between the electrode 211 and the electrode 213 of the second vibration element 21, the vibration layer 212 expands and contracts, and a periodic stress is applied to the first vibration member 91 via the elastic member 41, the elastic member 51, and the first vibration element 11. The transmitted stress causes the first vibration member 91 to bend and vibrate, and vibration and / or sound based on an audio signal is generated.

[0086] The material of the vibration layer 112 and the vibration layer 212 is not particularly limited, but since it can increase the amount of displacement, a material with good piezoelectricity such as lead zirconate titanate can be used. As another example, the material used for the vibration layer 112 and the vibration layer 212 can include a ceramic-based piezoelectric material that can achieve relatively high vibration. As yet another example, the vibration layer 112 and the vibration layer 212 can include a piezoelectric ceramic material having a crystal structure of the Perovskite series. Also, the vibration layer 112 and the vibration layer 212 can have a polycrystalline structure, but can also have a single crystal structure. For example, the vibration layer 112 and the vibration layer 212 can be made of a polycrystalline ceramic or a single crystal ceramic. Also, the vibration layer 112 and the vibration layer 212 can be made of a PVDF (polyvinylidene fluoride)-based material or a material containing a piezoelectric material containing lead (Pb), but can also be made of a piezoelectric material that does not contain lead. Examples of the piezoelectric material containing lead include one or more of PZT (Lead Zirconate Titanate)-based materials, PZNN (Lead Zirconate Nickel Niobate)-based materials, PMN (Lead Magnesium Niobate)-based materials, PNN (Lead Nickel Niobate)-based materials, PZN (Lead Zirconate Niobate)-based materials, and PIN (Lead Indium Niobate)-based materials. Examples of the piezoelectric material not containing lead include one or more of barium titanate (BaTiO3), calcium titanate (CaTiO3), and strontium titanate (SrTiO3), but the embodiments of the present specification are not limited thereto.

[0087] The adhesive member 61 and the adhesive member 62 may be a pressure-bonding resin material, an adhesive, an adhesive tape, or the like, but the embodiments of the present specification are not limited thereto. The elastic modulus of the adhesive member 61 and the adhesive member 62 may be the same or different from each other. For example, the adhesive member 61 may have a lower elastic modulus than the adhesive member 62. Although not shown in FIG. 16, each side of the first vibration element 11 and the second vibration element 21 may be covered with an insulator such as a resin to avoid shorting with other members.

[0088] The material of the first electrode (111, 211) and the second electrode (113, 213) of the first vibration element 11 and the second vibration element 21 may include a transparent conductive material, a semi-transparent conductive material, or an opaque conductive material. For example, as a transparent or semi-transparent conductive material, the first electrode and the second electrode may include one or more of ITO (indium tin oxide) or IZO (indium zinc oxide), but the embodiment of the present specification is not limited thereto. As an opaque conductive material, the first electrode and the second electrode may include one or more of aluminum (Al), copper (Cu), gold (Au), silver (Ag), molybdenum (Mo), or magnesium (Mg), or an alloy thereof, but the embodiment of the present specification is not limited thereto.

[0089] The acoustic device 1 according to this embodiment can also generate flat and high sound pressure in the low-mid frequency range while suppressing the occurrence of cracks. Therefore, according to the present disclosure, the sound quality of the acoustic device can be further improved.

[0090] [Fourth embodiment] In this embodiment, a modified example of the structure of the vibration element in the acoustic device 1 according to the fourth embodiment will be described. Fig. 17 is a plan view showing the structure of the vibration element according to this embodiment. Fig. 18 is a cross-sectional view taken along line D-D' in Fig. 17 according to this embodiment. Figs. 17 and 18 show the structures of the vibration elements shown in Figs. 11 to 18.

[0091] As shown in FIGS. 17 and 18, the first vibration element 11 according to this embodiment can include a vibration generating section (or a vibration section) 11A.

[0092] The vibration generating unit 11A may include a vibration layer 112, a first electrode 111 on a first surface of the vibration layer 112, and a second electrode 113 on a second surface of the vibration layer 112 different from the first surface. The vibration layer 112 may be substantially the same as the vibration layer 112 described in FIG. 7 or FIG. 16, so a duplicated description thereof will be omitted. The first electrode 111 and the second electrode 113 are arranged to sandwich the vibration layer 112 in the thickness direction, and apply a voltage to the vibration layer 112. The polarization direction of the vibration layer 112 may be the positive or negative direction of the z-axis. Wiring for applying a voltage to each electrode may be connected to the first electrode 111 and the second electrode 113.

[0093] The first vibration element 11 according to this embodiment may further include a first protective layer (or a first protective member) 117 and a second protective layer (or a second protective member) 118. The first protective layer 117 may be connected to a first surface (or a front surface or a top surface) of the vibration generating unit 11A. The first protective layer 117 protects and insulates the first surface of the vibration generating unit 11A. The second protective layer 118 may be connected to a second surface (or a back surface or a bottom surface) of the vibration generating unit 11A. The second protective layer 118 protects and insulates the second surface of the vibration generating unit 11A. For example, any one of the first protective layer 117 and the second protective layer 118 of the first vibration element 11 may be connected to the vibration member via adhesive layers 119a and 119b. For example, the adhesive layers 119a and 119b may be composed of an adhesive resin material, an adhesive, an adhesive tape, or the like, but the embodiment of the present specification is not limited thereto. The adhesive layers 119a, 119b may include an epoxy-based, an acrylic-based, a silicone-based, or a urethane-based material, and embodiments herein are not limited thereto.

[0094] The first protective layer 117 may be connected or bonded to the first electrode 111 via a first adhesive layer 119a. The second protective layer 118 may be connected or bonded to the second electrode 113 via a second adhesive layer 119b. The first adhesive layer 119a and the second adhesive layer 119b may be configured between the first protective layer 117 and the second protective layer 118 so as to completely surround the vibration generating unit 11A. For example, the vibration generating unit 11A may be embedded or built-in between the first adhesive layer 119a and the second adhesive layer 119b. For example, the first protective layer 117 and the second protective layer 118 may be a polyimide film, a polyethylene terephthalate film, or polyethylene naphthalate, but the embodiments of the present specification are not limited thereto.

[0095] The structure of the second vibration element 21 according to this embodiment is similar to that of the fourth embodiment, and therefore a description thereof will be omitted.

[0096] [Fifth embodiment] In this embodiment, a modified example of the structure of the vibration layer in the vibration element of the acoustic device 1 according to the fourth embodiment will be described. Fig. 19 is a perspective view showing the vibration layer in the vibration element of the acoustic device according to this embodiment.

[0097] 19, the vibration layer 112 of the vibration generating section 11A in the first vibration element 11 according to this embodiment may include a plurality of first portions 112a and one or more second portions 112b. For example, the vibration layer 112 may include a plurality of first portions 112a and a plurality of second portions 112b between the plurality of first portions 112a. For example, the plurality of first portions 112a and the plurality of second portions 112b may be alternately and repeatedly arranged along the x-axis direction, but the embodiment of the present specification is not limited thereto.

[0098] Each of the plurality of first portions 112a may include an inorganic material having a piezoelectric characteristic. For example, each of the plurality of first portions 112a may be an inorganic material portion or a piezoelectric material portion. Each of the plurality of first portions 112a may have a first width parallel to the x-axis direction and extend along the y-axis direction. Each of the plurality of first portions 112a may be substantially the same as the vibration layer 112 described in FIG. 7 or FIG. 16, and therefore, a duplicate description thereof will be omitted.

[0099] Each of the second portions 112b may be disposed between the first portions 112a. For example, each of the first portions 112a may be disposed between two adjacent second portions 112b among the second portions 112b. For example, the first portions 112a and the second portions 112b may include line or stripe shapes having the same or different sizes.

[0100] Each of the plurality of second portions 112b may be configured to fill a gap between two adjacent first portions 112a. Each of the plurality of first portions 112a and each of the plurality of second portions 112b may be arranged (or aligned) parallel to each other on the same plane (or the same layer). Each of the plurality of second portions 112b may improve the durability of the first portion 112a by absorbing an impact applied to the first portion 112a, and may provide flexibility to each of the first vibration element 11 and the second vibration element 21. Each of the plurality of second portions 112b may include an organic material having soft properties. For example, the plurality of second portions 112b may be one or more of an epoxy-based polymer, an acrylic-based polymer, and a silicone-based polymer, but the embodiments herein are not limited thereto. For example, each of the plurality of second portions 112b may be expressed as an organic part, an organic material, an adhesive part, an elastic part, a bending part, a damping part, an elastic part, a resilient part, or a soft part, but the embodiments herein are not limited thereto.

[0101] A first surface of each of the first portions 112a and the second portions 112b may be commonly coupled to a first electrode. A second surface of each of the first portions 112a and the second portions 112b may be commonly coupled to a second electrode.

[0102] The vibration layer 112 in the first vibration element 11 of the acoustic device 1 according to the fifth embodiment can have a single thin film shape by arranging (or connecting) a plurality of first portions 112a and second portions 112b on the same plane. This allows the first vibration element 11 to vibrate in the up and down direction by the first portions 112a having vibration characteristics, and to bend into a curved shape by the second portions 112b having flexibility. For example, the first vibration element 11 including the vibration layer 112 can have a resonance frequency of 20 kHz or less by having a 2-2 composite structure, but the embodiments of the present specification are not limited thereto.

[0103] The structure of the second vibration element 21 according to this embodiment is similar to that of the fifth embodiment, and therefore a description thereof will be omitted.

[0104] [Sixth embodiment] In this embodiment, another modified example of the structure of the vibration layer in the vibration element of the acoustic device 1 according to the sixth embodiment will be described. Fig. 20 is a perspective view showing the vibration layer in the vibration element of the acoustic device according to this embodiment.

[0105] 20, the vibration layer 112 of the vibration generating section 11A in the first vibration element 11 according to this embodiment can include a plurality of first portions 112a and a second portion 112b. For example, the vibration layer 112 can include a plurality of first portions 112a and a second portion 112b disposed between the plurality of first portions 112a.

[0106] The first portions 112a may be arranged to be spaced apart from one another along the x-axis direction and the y-axis direction. For example, the first portions 112a may be arranged in a lattice shape having hexahedral shapes of the same size. Each of the first portions 112a may be substantially the same as the first portion 112a described in FIG. 19, and therefore a duplicate description thereof will be omitted.

[0107] The second portion 112b may be disposed between the first portions 112a along each of the x-axis direction and the y-axis direction. The second portion 112b may be connected to or bonded to the adjacent first portions 112a by filling a gap between two adjacent first portions 112a or by being configured to surround each of the first portions 112a. The second portion 112b may be substantially the same as the second portion 112b described in FIG. 19, and therefore a duplicate description thereof will be omitted.

[0108] A first surface of each of the plurality of first portions 112a and the second portions 112b may be commonly coupled to a first electrode, and a second surface of each of the plurality of first portions 112a and the second portions 112b may be commonly coupled to a second electrode.

[0109] The vibration layer 112 in the first vibration element 11 of the acoustic device 1 according to the sixth embodiment can have a single thin film shape by arranging (or connecting) a plurality of first portions 112a and second portions 112b on the same plane. This allows the first vibration element 11 to vibrate in the up and down direction by the first portions 112a having vibration characteristics, and to bend into a curved shape by the second portions 112b having flexibility. For example, the first vibration element 11 including the vibration layer 112 can have a resonance frequency of 20 kHz or less by having a 1-3 composite structure, but the embodiments of the present specification are not limited thereto.

[0110] The structure of the second vibration element 21 according to this embodiment is similar to that of the sixth embodiment, and therefore a description thereof will be omitted.

[0111] [Seventh embodiment] In this embodiment, a modified example of the structure of the vibration element in the acoustic device 1 according to the seventh embodiment will be described.

[0112] Fig. 21 is a plan view showing the configuration of a vibration element in an acoustic device according to this embodiment. Fig. 22 shows a cross-sectional view taken along line E-E' in Fig. 21. Figs. 21 and 22 show the structure of the vibration element shown in Figs. 1 to 10.

[0113] 21 and 22, the first vibration element 11 according to this embodiment may include at least two vibration generating units (or vibration units) 11A and 11B. For example, the first vibration element 11 may include a first vibration generating unit 11A and a second vibration generating unit 11B.

[0114] The first and second vibration generating units 11A and 11B may be arranged to be electrically separated from each other along the x-axis direction. The first and second vibration generating units 11A and 11B may vibrate by alternately repeating contraction and / or expansion due to the piezoelectric effect. For example, the first and second vibration generating units 11A and 11B may be arranged or tiled at a first interval (D1) along the x-axis (or y-axis) direction. The first and second vibration generating units 11A and 11B may be arranged or tiled on the same plane, so that the vibration element 11 can be enlarged by tiling the first and second vibration generating units 11A and 11B, which have a relatively small size. Thus, the vibration element 11, in which the first and second vibration generating units 11A and 11B are tiled, may be a vibration array, a vibration array section, a vibration module array section, a vibration array structure, a tiling vibration array, a tiling vibration array module, or a tiling vibration film, but the embodiment of the present specification is not limited thereto.

[0115] The first and second vibration generating units 11A and 11B may be arranged at a constant interval (D1) or tiled to be realized as one vibration device (or a single vibration device) that is not driven independently but is driven in the form of one complete unit. The first interval (D1) between the first and second vibration generating units 11A and 11B based on the x-axis direction may be 0.1 mm or more and less than 3 cm, but the embodiment of the present specification is not limited thereto.

[0116] In order to increase the reproduction band of the sound generated in conjunction with the single-body vibration of the first and second vibration generating units 11A and 11B and to increase the sound pressure characteristics of low-frequency sound, for example, at 500 Hz or less, the first and second vibration generating units 11A and 11B may be arranged with a first distance (D1) of 0.1 mm or more and less than 5 mm. For example, when the first and second vibration generating units 11A and 11B are arranged with a first distance (D1) of less than 0.1 mm or without the first distance (D1), the reliability of the first and second vibration generating units 11A and 11B or the vibration element 11 may be reduced due to cracks or breakage caused by physical contact between each other when the first and second vibration generating units 11A and 11B vibrate, respectively.

[0117] Each of the first and second vibration generating units 11A and 11B may include a vibration layer 112, a first electrode 111 on a first surface of the vibration layer 112, and a second electrode 113 on a second surface of the vibration layer 112 different from the first surface. The vibration layer 112 may be substantially the same as the vibration layer 112 described in FIG. 7 or FIG. 16, so a duplicated description thereof will be omitted. According to another modified example, the vibration layer 112 may include a plurality of first portions 112a and a plurality of second portions 112b as in the modified example shown in FIG. 19, or may include a plurality of first portions 112a and a plurality of second portions 112b as in the modified example shown in FIG. 20, and a duplicated description thereof will be omitted.

[0118] The first electrode 111 and the second electrode 113 are arranged to sandwich the vibration layer 112 in the thickness direction, and apply a voltage to the vibration layer 112. The polarization direction of the vibration layer 112 may be the positive direction or the negative direction of the z axis. Wiring may be connected to the first electrode 111 and the second electrode 113 to apply a voltage to each electrode.

[0119] Each of the first vibration element 11 and the second vibration element 21 according to this embodiment may further include a first protective layer (or a first protective member) 117 and a second protective layer (or a second protective member) 118. The first protective layer 117 may be commonly connected to the first surfaces (or the front surfaces or the top surfaces) of the first and second vibration generating units 11A and 11B. The first protective layer 117 may protect and / or insulate the first surfaces of the first and second vibration generating units 11A and 11B. The second protective layer 118 may be commonly connected to the second surfaces (or the back surfaces or the bottom surfaces) of the first and second vibration generating units 11A and 11B. The second protective layer 118 may protect and / or insulate the second surfaces of the first and second vibration generating units 11A and 11B. For example, the first protective layer 117 and the second protective layer 118 may be a polyimide film, a polyethylene terephthalate film, or a polyethylene naphthalate film, although embodiments herein are not limited thereto.

[0120] The first protective layer 117 may be connected or bonded to the first electrode 111 via a first adhesive layer 119a. The second protective layer 118 may be connected or bonded to the second electrode 113 via a second adhesive layer 119b. The first adhesive layer 119a and the second adhesive layer 119b may be configured between the first protective layer 117 and the second protective layer 118 so as to surround each of the first and second vibration generating units 11A and 11B. For example, the first adhesive layer 119a and the second adhesive layer 119b may be configured between the first protective layer 117 and the second protective layer 118 so as to completely surround each of the first and second vibration generating units 11A and 11B. The first adhesive layer 119a and the second adhesive layer 119b may be connected or bonded to each other between the first vibration generating unit 11A and the second vibration generating unit 11B. For example, the first and second vibration generating units 11A and 11B may be embedded or built in between the first adhesive layer 119a and the second adhesive layer 119b. The first adhesive layer 119a and the second adhesive layer 119b may include an epoxy-based, an acrylic-based, a silicone-based, or a urethane-based material, and the embodiment of the present specification is not limited thereto.

[0121] The structure of the second vibration element 21 according to this embodiment is similar to that of the seventh embodiment, and therefore a description thereof will be omitted.

[0122] [Eighth embodiment] In this embodiment, a specific configuration example can be described in which the acoustic device 1 according to the first embodiment is a display device, and the first vibrating member 91 also functions as a display panel of the display device. Descriptions of elements common to the first embodiment may be omitted or simplified.

[0123] FIG. 23 is a configuration diagram of a display device 70 according to an eighth embodiment. The display device 70 of this embodiment may be used, for example, as an electronic poster, a digital bulletin board, an electronic billboard, a computer screen, a television receiver, etc., but the embodiment of this specification is not limited thereto. The structures of the host system 7, the first vibration element 11, and the second vibration element 21 are similar to those of the first embodiment, so that the description thereof can be omitted. In addition, the elastic members 41, 51, etc. of the first embodiment may be connected to the first vibration element 11 and the second vibration element 21.

[0124] 23, the display device 70 may have an acoustic device including a first vibration element 11 and a second vibration element 21, a control unit 200, a panel control unit 300, a data driving circuit 400, a gate driving circuit 500, and a display panel 600. The display device 70 may be a device that displays an image on the display panel 600 based on input RGB data (or RGBW data) or the like, and generates sound based on input driving signals or the like.

[0125] The panel control unit 300 can control the data driving circuit 400 and the gate driving circuit 500 based on image data and timing signals input from the host system 7. The data driving circuit 400 can supply data voltages and the like to the pixels (P) via driving lines 410 arranged for each column of the pixels (P). The gate driving circuit 500 can supply control signals to the pixels (P) via driving lines 510 arranged for each row of the pixels (P). Each of the driving lines 410 and the driving lines 510 can be composed of a plurality of wirings.

[0126] The display panel 600 may include a plurality of pixels (P) arranged in a plurality of rows and a plurality of columns. If the display device 70 is capable of displaying a color image, the pixels (P) may be sub-pixels that display any of a plurality of colors (e.g., RGB or RGBW) that make up the color image.

[0127] The display panel 600 used in one or more embodiments of the present specification may be a display panel of any shape, such as a liquid crystal display panel, an organic light-emitting display panel, and an electroluminescent display panel, and the embodiments of the present specification are not limited thereto. For example, the display panel 600 may be a display panel that can generate sound by being vibrated by an acoustic device according to an embodiment of the present specification. The display panel 600 applied to the display device 70 according to an embodiment of the present specification is not limited to the shape or size of the display panel 600.

[0128] According to one or more embodiments herein, when the display panel 600 is a liquid crystal display panel, the display panel 600 may include a plurality of gate lines, a plurality of data lines, and a plurality of pixels (P) formed at each of the intersection regions of the gate lines and the data lines. The display panel 600 may include an array substrate including thin film transistors that are switching elements for adjusting the light transmittance of each pixel (P), an upper substrate including a color filter and / or a black matrix, and a liquid crystal layer formed between the array substrate and the upper substrate.

[0129] When the display panel 600 is an organic light emitting display panel, the display panel 600 may include a plurality of gate lines, a plurality of data lines, and a plurality of pixels (P) formed at each of the intersection regions of the gate lines and the data lines. The display panel 600 may include an array substrate including a thin film transistor, which is an element for selectively applying a voltage to each pixel (P), an organic light emitting element layer on the array substrate, and a sealing substrate or encapsulation substrate disposed on the array substrate to cover the organic light emitting element layer. The sealing substrate may protect the thin film transistor and the organic light emitting element layer from external impact and prevent moisture or oxygen from penetrating into the organic light emitting element layer. The layer formed on the array substrate may include an inorganic light emitting layer, for example, a nano-sized material layer, and a quantum dot light emitting layer. In another embodiment of the present specification, the layer formed on the array substrate may include a micro light emitting diode.

[0130] The display panel 600 may further include a backing, such as a metal plate, attached to the display panel 600. The display panel 600 may also include other structures, for example, other structures made of other materials.

[0131] Each of the control unit 200, the panel control unit 300, the data driving circuit 400, and the gate driving circuit 500 may be configured by one or more semiconductor integrated circuits. In addition, some or all of the control unit 200, the panel control unit 300, the data driving circuit 400, and the gate driving circuit 500 may be integrated into one semiconductor integrated circuit.

[0132] The display device 70 of this embodiment can display an image and / or emit a sound by receiving an image signal (e.g., RGB data or RGBW data), a drive signal, and a timing signal (e.g., a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, etc.) from the host system 7. The display panel 600 can have an image display surface that displays an image, and a back surface that faces the image display surface. The first vibration element 11 and the second vibration element 21 can be connected to the back surface of the display panel 600. For example, the vibration generated by the first vibration element 11 and the second vibration element 21 can be transmitted to the back surface of the display panel 600. The display panel 600 can have a function of image display and a function of the first vibration member 91 in the first embodiment. In this embodiment, a display device 70 having an acoustic effect in which a sound is emitted from an image displayed on the display panel 600 can be provided.

[0133] The audio device according to the embodiment of the present specification may be applied to or may include an audio device disposed in an apparatus. The apparatus according to the embodiment of the present specification may be applied to a mobile device, a video phone, a smart watch, a watch phone, a wearable apparatus, a foldable apparatus, a rollable apparatus, a bendable apparatus, a flexible apparatus, a curved apparatus, a sliding apparatus, a variable apparatus, an electronic organizer, an electronic book, a portable multimedia player (PMP), a personal digital assistant (PDA), an MP3 player, a mobile medical device, a desktop PC, a laptop PC, a netbook computer, a workstation, a navigation system, a vehicle navigation system, a vehicle display device, a vehicle device, a theater device, a theater display device, a television, a wallpaper device, a signage device, a game device, a notebook, a monitor, a camera, a video camera, and a home appliance. The acoustic device of the present specification may be applied to or include an organic light-emitting lighting device or an inorganic light-emitting lighting device. When the acoustic device is applied to a lighting device, the lighting device may play the role of lighting and a speaker. When the acoustic device of the present specification is applied to or includes a mobile device, the acoustic device may be one or more of a speaker, a receiver, and a haptic device, and the embodiment of the present specification is not limited thereto.

[0134] The acoustic device according to the embodiment of the present specification can be described as follows.

[0135] An acoustic device according to an embodiment of the present specification may include a first vibration member, a first vibration element including rectangular first and second main surfaces facing each other, the first main surface being in contact with the first vibration member, and vibrating in response to an input drive signal, a second vibration member including rectangular first and second main surfaces facing each other, a portion of the first main surface of the second vibration member being connected to a portion of the second main surface of the first vibration element via an elastic member, and the second vibration element including rectangular first and second main surfaces facing each other, the first main surface of the second vibration element being in contact with the second main surface of the second vibration member, and vibrating in response to an input drive signal, and the first vibration element may be arranged in a direction rotated at a predetermined angle around an axis perpendicular to the first main surface of the second vibration element and the second main surface of the second vibration element.

[0136] According to one or more embodiments herein, the second main surface of the first vibration element may include a portion that does not overlap with the second main surface of the second vibration element and the second main surface of the second vibration member in a plan view.

[0137] According to one or more embodiments herein, the first vibration element can have the same shape as the plate shape of the second vibration element.

[0138] According to one or more embodiments herein, the first vibration element includes four corner portions that include a portion of the second main surface of the first vibration element, and the corner portions may include portions that do not overlap with the second main surface of the second vibration element and the second main surface of the second vibration member.

[0139] According to one or more embodiments herein, the elastic member may be disposed at the corner so as to be in contact with the second main surface of the first vibration element.

[0140] According to one or more embodiments herein, the first vibration element and the second vibration member may not be in direct contact with each other.

[0141] According to one or more embodiments of the present specification, the second vibration member can be connected to the first vibration element via an elastic member arranged in a region including the center of the second main surface of the first vibration element in a planar view.

[0142] According to one or more embodiments herein, the second main surface of the first vibration element has a short side and a long side, the second main surface of the second vibration member has a short side and a long side, and the second vibration member can be arranged such that, in a planar view, the long side of the second main surface of the second vibration member intersects with the long side of the second main surface of the first vibration element.

[0143] According to one or more embodiments of the present specification, the second vibrating member can be disposed such that the long side of the second main surface of the second vibrating member is perpendicular to the long side of the second main surface of the first vibrating element in a plan view.

[0144] According to one or more embodiments herein, a short side of the second major surface of the second vibrating member can be parallel to a long side of the second major surface of the first vibrating element.

[0145] According to one or more embodiments herein, the first vibrating member has a flat plate shape including a main surface, and the entire first main surface of the first vibrating element can be in contact with the main surface of the first vibrating member.

[0146] According to one or more embodiments herein, the entirety of the first major surface of the second vibrating element can be in contact with the second major surface of the second vibrating member.

[0147] According to one or more embodiments herein, the second vibrating member includes four corners including a portion of a first main surface of the second vibrating member, the elastic members are arranged at the corners so as to contact the first main surface of the second vibrating member, and the first vibrating member can be connected to the second vibrating member via the elastic members.

[0148] According to one or more embodiments herein, the drive signal input to the second vibration element may have the same phase as the drive signal input to the first vibration element.

[0149] According to one or more embodiments herein, the drive signal input to the second vibration element may have an opposite phase to the phase of the drive signal input to the first vibration element.

[0150] According to one or more embodiments herein, at least one of the first vibrating member and the second vibrating member may include stainless steel.

[0151] According to one or more embodiments herein, at least one of the first vibration element and the second vibration element may be a piezoelectric element.

[0152] An acoustic device according to an embodiment of the present specification may include a first vibrating member, a second vibrating member overlapping the first vibrating member and having a smaller size than the first vibrating member, a first vibrating element located between the first vibrating member and the second vibrating member and connected to the first vibrating member, and a second vibrating element connected to the second vibrating member, and the second vibrating member may be configured to be connected to the first vibrating element and the first vibrating member.

[0153] According to one or more embodiments herein, the center of the first vibration element and the center of the second vibration element may be overlapped with each other, and the first vibration element and the second vibration element may be arranged in a direction rotated at a predetermined angle around the center.

[0154] According to one or more embodiments herein, each of the first vibration element, the second vibration element, the first vibration member, and the second vibration member may have a rectangular or substantially square shape in a plan view.

[0155] According to one or more embodiments herein, the acoustic device may further include an elastic member disposed between a central region of the first vibration element and a central region of the second vibration member, and each of the first vibration element, the second vibration element, the first vibration member and the second vibration member may have an approximately square shape in a planar view.

[0156] According to one or more embodiments herein, the acoustic device may further include a first connecting member configured to connect the second vibrating member to the first vibrating member, and a second connecting member configured to connect the second vibrating member to the first vibrating element.

[0157] According to one or more embodiments herein, each of the first vibration element, the second vibration element, the first vibration member and the second vibration member has an approximately square shape in a planar view, the first connecting member is connected to a corner of the second vibration member, and the second connecting member can be connected between the corner of the first vibration element and the second vibration member.

[0158] According to one or more embodiments of the present specification, each of the first vibration element, the second vibration element, the first vibration member and the second vibration member has a rectangular shape in a planar view, the first connecting member is connected to a corner of the second vibration member, and the second connecting member can be disposed between two adjacent first connecting members along the longitudinal direction of the long side of the second vibration member.

[0159] In accordance with one or more embodiments herein, the second vibrating member includes at least one of the following materials: metal, resin, glass, wood, rubber, plastic, fiber, cloth, paper, leather, or carbon, and the first vibrating member may be at least one of a display panel including pixels configured to display an image, a screen panel onto which an image is projected from a display device, a lighting panel, a light emitting diode lighting panel, an organic light emitting lighting panel, an inorganic light emitting lighting panel, a signage panel, an interior material of a vehicle, a glass window of a vehicle, an exterior material of a vehicle, a seat interior material of a vehicle, a ceiling material of a vehicle, a ceiling material of a building, an interior material of a building, a glass window of a building, an interior material of an aircraft, a glass window of an aircraft, and a mirror.

[0160] According to one or more embodiments herein, the first vibration member is a display panel of a display device, the display panel including an image display surface on which an image is displayed and a back surface opposite the image display surface, and vibrations generated by the first vibration element and the second vibration element can be transmitted to the back surface of the display panel.

[0161] The present specification described above is not limited to the above-mentioned embodiment and the attached drawings, and various substitutions, modifications and changes are possible within the scope of the technical idea of ​​the specification. Therefore, the scope of the specification is indicated by the claims described below, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the specification. [Explanation of symbols]

[0162] 1 Sound equipment 11 First vibration element 21 Second vibration element 41, 51 Elastic member 91 First vibration member 92 Second vibration member

Claims

1. A first vibration member; a first vibration element including a first main surface and a second main surface of a rectangular shape facing each other, the first main surface being in contact with the first vibration member, and vibrating in response to an input drive signal; a second vibration member including a rectangular first main surface and a rectangular second main surface facing each other, a part of the first main surface of the second vibration member being coupled to a part of the second main surface of the first vibration member and the first vibration element via an elastic member; a second vibration element including a first principal surface and a second principal surface of a rectangle facing each other, the first principal surface of the second vibration element being in contact with the second principal surface of the second vibration member, and the second vibration element vibrating in response to an input drive signal; Equipped with The first vibration element is arranged in a direction rotated at a predetermined angle around an axis perpendicular to the first main surface of the second vibration element and the second main surface of the second vibration element. sound equipment.

2. The acoustic device according to claim 1 , wherein the second main surface of the first vibration element includes a portion that does not overlap with the second main surface of the second vibration element and the second main surface of the second vibration member in a plan view.

3. The acoustic device according to claim 2 , wherein the first vibration element has the same shape as the flat plate shape of the second vibration element.

4. the first vibration element includes four corners including a portion of the second main surface of the first vibration element, The acoustic device according to claim 2 , wherein the corner portion includes the portion that does not overlap with the second main surface of the second vibration element and the second main surface of the second vibration member.

5. The acoustic device according to claim 4 , wherein the elastic member is disposed at the corner portion so as to be in contact with the second main surface of the first vibration element.

6. The acoustic device of claim 5 , wherein the first vibrating element and the second vibrating member are not in direct contact with each other.

7. The acoustic device according to claim 5 , wherein the second vibration member is connected to the first vibration element via an elastic member disposed in a region including a center of the second main surface of the first vibration element in a plan view.

8. the second main surface of the first vibration element has a short side and a long side, the second main surface of the second vibrating member has a short side and a long side, The second vibration member is disposed such that the long side of the second main surface of the second vibration member intersects with the long side of the second main surface of the first vibration element in a plan view.

3. An acoustic device according to claim 2.

9. The second vibration member is disposed such that the long side of the second main surface of the second vibration member is perpendicular to the long side of the second main surface of the first vibration element in a plan view.

9. An acoustic device according to claim 8.

10. The short side of the second main surface of the second vibration member is parallel to the long side of the second main surface of the first vibration element.

9. An acoustic device according to claim 8.

11. The first vibration member has a flat plate shape including a main surface, The acoustic device according to claim 1 , wherein an entire surface of the first main surface of the first vibration element is in contact with the main surface of the first vibration member.

12. The acoustic device according to claim 11 , wherein an entire surface of the first main surface of the second vibration element is in contact with the second main surface of the second vibration member.

13. the second vibration member includes four corners including a portion of the first main surface of the second vibration member, the elastic member is disposed at the corner portion so as to be in contact with the first main surface of the second vibrating member, The first vibration member is connected to the second vibration member via the elastic member.

13. An acoustic device as claimed in claim 12.

14. The acoustic device according to claim 1 , wherein the drive signal input to the second vibration element has the same phase as a phase of the drive signal input to the first vibration element.

15. The acoustic device according to claim 1 , wherein the drive signal input to the second vibration element has a phase opposite to a phase of the drive signal input to the first vibration element.

16. The acoustic device of claim 1 , wherein at least one of the first vibrating member and the second vibrating member comprises stainless steel.

17. The acoustic device of claim 1 , wherein at least one of the first vibration element and the second vibration element is a piezoelectric element.

18. A first vibration member; a second vibration member overlapping the first vibration member and having a size smaller than that of the first vibration member; a first vibration element located between the first vibration member and the second vibration member and coupled to the first vibration member; a second vibration element coupled to the second vibration member; Equipped with The second vibration member is configured to be coupled to the first vibration element and the first vibration member. sound equipment.

19. A center portion of the first vibration element and a center portion of the second vibration element are overlapped with each other, The acoustic device according to claim 18 , wherein the first vibration element and the second vibration element are arranged in a direction rotated at a predetermined angle around the center.

20. The acoustic device according to claim 19 , wherein each of the first vibration element, the second vibration element, the first vibration member, and the second vibration member has a rectangular or substantially square shape in a plan view.

21. further comprising an elastic member disposed between a central region of the first vibration element and a central region of the second vibration member; The acoustic device according to claim 19 , wherein each of the first vibration element, the second vibration element, the first vibration member, and the second vibration member has a substantially square shape in a plan view.

22. a first connecting member configured to connect the second vibrating member to the first vibrating member; 20. The acoustic device of claim 19, further comprising: a second coupling member configured to couple the second vibrating member to the first vibrating element.

23. each of the first vibration element, the second vibration element, the first vibration member, and the second vibration member has a substantially square shape in a plan view; The first connecting member is connected to a corner portion of the second vibrating member, The acoustic device according to claim 22 , wherein the second connecting member is connected between a corner of the first vibration element and the second vibration member.

24. each of the first vibration element, the second vibration element, the first vibration member, and the second vibration member has a rectangular shape in a plan view; The first connecting member is connected to a corner portion of the second vibrating member, The acoustic device according to claim 22 , wherein the second connecting member is disposed between two adjacent first connecting members along a longitudinal direction of the long side of the second vibrating member.

25. the second vibration member includes at least one material selected from the group consisting of metal, resin, glass, wood, rubber, plastic, fiber, cloth, paper, leather, and carbon; 25. The acoustic device of claim 1, wherein the first vibrating member is at least one of a display panel including pixels configured to display an image, a screen panel onto which an image is projected from a display device, a lighting panel, a light emitting diode lighting panel, an organic light emitting lighting panel, an inorganic light emitting lighting panel, a signage panel, an interior material of a vehicle, a glass window of a vehicle, an exterior material of a vehicle, a seat interior material of a vehicle, a ceiling material of a vehicle, a ceiling material of a building, an interior material of a building, a glass window of a building, an interior material of an aircraft, a glass window of an aircraft, and a mirror.

26. the first vibrating member is a display panel of a display device, the display panel includes an image display surface on which an image is displayed and a back surface opposed to the image display surface; The acoustic device according to claim 1 , wherein vibrations generated by the first vibration element and the second vibration element are transmitted to the rear surface of the display panel.

Images