Flat panel loudspeaker and vehicle comprising a flat panel loudspeaker

Abstract

A flat panel speaker and a vehicle including the same are disclosed. The flat panel speaker includes a substrate, a plurality of horizontal frames disposed on the substrate and dividing the substrate into a plurality of rows, a plurality of vertical frames disposed on the substrate and dividing each of the plurality of rows into a plurality of columns, a plurality of piezoelectric elements disposed on a side of each of the plurality of vertical frames and configured to contract and expand according to a voltage signal, a plurality of electrodes configured to apply the voltage signal to the piezoelectric elements, and a controller configured to control the voltage signal applied to the plurality of electrodes.

Description

Technical Field

[0001] The present invention relates to a flat panel speaker and a vehicle including a flat panel speaker. Background Technology

[0002] Because voice coil speakers installed in vehicles generate sound waves by moving a diaphragm, the diaphragm vibrates very much and produces noise when outputting high sound pressure levels or low-frequency sounds.

[0003] In addition, because voice coil speakers inherently require a magnetic field to move the voice coil, and require baffles and housings, they occupy a large volume in the limited space of a vehicle. Summary of the Invention

[0004] This invention relates to a flat panel loudspeaker including a piezoelectric element and a vehicle including the flat panel loudspeaker. Specific embodiments relate to a flat panel loudspeaker including a piezoelectric element and a vehicle including the flat panel loudspeaker.

[0005] Embodiments of the present invention provide a flat panel speaker and a vehicle including the flat panel speaker, which can prevent noise generated by the vibration of the diaphragm and requires a relatively small size in the vehicle.

[0006] An exemplary embodiment of a flat panel loudspeaker may include: a substrate; a plurality of horizontal frames disposed on the substrate and dividing the substrate into a plurality of rows; a plurality of vertical frames disposed on the substrate and dividing each of the plurality of rows into a plurality of columns; a plurality of piezoelectric elements disposed on the side of each of the plurality of vertical frames and contracting and expanding according to a voltage signal; a plurality of electrodes for applying voltage signals to the piezoelectric elements; and a controller for controlling the voltage applied to the plurality of electrodes.

[0007] Multiple vertical frames may include multiple first vertical frames that divide any row of multiple rows into multiple columns and multiple second vertical frames that divide another row adjacent to any row into multiple columns, wherein the multiple first vertical frames and multiple second vertical frames are arranged alternately.

[0008] Multiple electrodes can be positioned on both sides of each of the multiple piezoelectric elements.

[0009] Multiple piezoelectric elements and multiple horizontal frames can form multiple independent lattices on a substrate, and the multiple piezoelectric elements can contract and expand in a direction parallel to the horizontal frames according to a voltage signal to change the volume of the multiple lattices.

[0010] The multiple piezoelectric elements may include a first piezoelectric element and a second piezoelectric element forming any one of the multiple pores, and the controller may control the voltage applied to the multiple electrodes so that the first piezoelectric element and the second piezoelectric element expand and contract simultaneously.

[0011] The plurality of piezoelectric elements may include a first piezoelectric element forming a first cavity in a plurality of cavities and a second piezoelectric element forming a second cavity, and the controller may control the voltage applied to the plurality of electrodes such that the voltage applied to the first piezoelectric element is greater than the voltage applied to the second piezoelectric element.

[0012] The first hole can be positioned closer to the center of the substrate than the second hole.

[0013] The height of each of the multiple horizontal frames, the height of each of the multiple vertical frames, and the height of each of the multiple piezoelectric elements can be the same.

[0014] The separation distance between each of the multiple horizontal frames can be equal to the width of each of the multiple vertical frames and the width of each of the multiple piezoelectric elements.

[0015] The vehicle according to an exemplary embodiment may include the flat panel speaker.

[0016] The flat panel speaker may further include an audio-video navigation (AVN) device, and the controller may control the intensity and frequency of the voltage applied to multiple electrodes based on the sound signal output from the AVN device.

[0017] The flat panel speaker according to an exemplary embodiment of this disclosure can occupy a small volume and can provide optimal sound. Attached Figure Description

[0018] These and / or other aspects of the invention will become apparent and more readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is a perspective view of a flat panel speaker according to an exemplary embodiment of the present invention;

[0020] Figure 2 This is a perspective view of a perforated grid included in a flat panel loudspeaker according to an exemplary embodiment of the present invention;

[0021] Figure 3 This is a cross-sectional view of a perforated grid included in a flat panel loudspeaker according to an exemplary embodiment of the present invention;

[0022] Figure 4 This is a diagram illustrating the expansion of a piezoelectric element according to an exemplary embodiment of the present invention;

[0023] Figure 5This is a diagram illustrating the shrinkage of a piezoelectric element according to an exemplary embodiment of the present invention; and

[0024] Figure 6 This is a diagram illustrating the sound pressure distribution of sound waves output from a plurality of apertures included in a flat panel loudspeaker according to an exemplary embodiment of the present invention. Detailed Implementation

[0025] In the following description, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When designating elements in the drawings by reference numerals, the same elements will be represented by the same reference numerals even if the same elements are shown in different drawings. Furthermore, in the following description of embodiments of the present disclosure, detailed descriptions of known functions and configurations incorporated herein will be omitted where such detailed descriptions may obscure the subject matter of the disclosure.

[0026] Throughout this specification, the same reference numerals refer to the same elements. Not all elements of embodiments of the invention will be described, and descriptions of those well-known in the art or overlapping with each other in exemplary embodiments will be omitted. Terms such as “part,” “module,” “component,” and “block” used throughout this specification may be implemented in software and / or hardware, and multiple “parts,” “modules,” “components,” or “blocks” may be implemented as a single element, or a single “part,” “module,” “component,” or “block” may include multiple elements.

[0027] It will be further understood that the term “connection” or its derivatives refer to both direct and indirect connections, and indirect connections include connections via wireless communication networks.

[0028] It will be further understood that, when used in this specification, the terms “comprising” and / or “including” identify the presence of the stated features, quantities, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or combinations thereof unless the context clearly indicates otherwise.

[0029] Ordinal terms such as "first" and "second" can be used to explain various components, but these components are not limited by these terms. These terms are only used for the purpose of distinguishing one component from another.

[0030] As used in this article, the singular forms “a,” “one,” and “the” are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0031] The reference numerals used for method steps are for illustrative purposes only and are not intended to limit the order of steps. Therefore, unless the context clearly indicates otherwise, the order may be practiced in other ways.

[0032] The operating principles and embodiments of the present invention will be described below with reference to the accompanying drawings.

[0033] Reference Figures 1 to 3 According to an exemplary embodiment, a flat panel speaker may include a substrate 10, a plurality of horizontal frames 20, a plurality of vertical frames 30, a plurality of piezoelectric elements 40, a plurality of electrodes 45, and a controller 50.

[0034] The substrate 10 can be formed in a rectangular shape, but the shape of the substrate 10 is not limited to this.

[0035] Multiple horizontal frames 20 can be disposed on the substrate 10 to divide the substrate 10 into multiple rows. The multiple horizontal frames 20 can be spaced apart from each other at the same pitch and arranged on the substrate 10 to divide the substrate 10 into multiple rows.

[0036] For example, the portion of substrate 10 blocked by the first horizontal frame 20-1 and the second horizontal frame 20-2 can be divided into a first row, the portion of substrate 10 blocked by the second horizontal frame 20-2 and the third horizontal frame 20-3 can be divided into a second row, the portion of substrate 10 blocked by the third horizontal frame 20-3 and the fourth horizontal frame 20-4 can be divided into a third row, and the portion of substrate 10 blocked by the fourth horizontal frame 20-4 and the fifth horizontal frame 20-5 can be divided into a fourth row.

[0037] Figure 1 The flat panel speaker shown is an example of a flat panel speaker according to an exemplary embodiment of the present invention, and there is no limitation on the number of the plurality of horizontal frames 20 and the number of the plurality of rows therebetween.

[0038] Alternatively, multiple vertical frames 30 can be provided on the substrate 10 to divide each of the multiple rows divided by multiple horizontal frames 20 into multiple columns. The multiple vertical frames 30 dividing the same rows can be spaced apart from each other at the same interval and arranged on the substrate 10 to divide the multiple rows into multiple columns.

[0039] For example, the portion of the first row on the substrate 10 that is blocked by the first vertical frame 30a-1 and the second vertical frame 30a-2 can be divided into the first column of the first row, the portion of the first row on the substrate 10 that is blocked by the second vertical frame 30a-2 and the third vertical frame 30a-3 can be divided into the second column of the first row, and the portion of the first row on the substrate 10 that is blocked by the third vertical frame 30a-3 and the fourth vertical frame 30a-4 can be divided into the third column of the first row.

[0040] As described above, the second, third, and fourth rows can also be divided into multiple columns by setting multiple vertical frames 30 in each row. That is, vertical frames 30b-1, 30b-2, 30b-3, and 30b-4 set in the second row can divide the second row into multiple columns, vertical frames 30c-1, 30c-2, 30c-3, and 30c-4 set in the third row can divide the third row into multiple columns, and vertical frames 30d-1, 30d-2, 30d-3, and 30d-4 set in the fourth row can divide the fourth row into multiple columns.

[0041] Multiple vertical frames 30 that divide any row into multiple columns and multiple vertical frames 30 that divide rows adjacent to any row into multiple columns can be arranged alternately.

[0042] Specifically, the multiple first vertical frames 30a that divide the first row into multiple columns and the multiple second vertical frames 30b that divide the second row into multiple columns can be arranged alternately.

[0043] Similarly, multiple second vertical frames 30b that divide the second row into multiple columns and multiple third vertical frames 30c that divide the third row into multiple columns can be arranged alternately, and multiple third vertical frames 30c that divide the third row into multiple columns and multiple fourth vertical frames 30d that divide the fourth row into multiple columns can be arranged alternately.

[0044] The alternating arrangement of multiple first vertical frames 30a and multiple second vertical frames 30b means that when multiple first vertical frames 30a extend in the vertical direction, they do not overlap with multiple second vertical frames 30b.

[0045] That is, assuming that multiple first vertical frames 30a and multiple second vertical frames 30b are arranged in the same row, the multiple first vertical frames 30a and multiple second vertical frames 30b can be arranged to intersect each other.

[0046] When multiple vertical frames 30, which divide any row into multiple columns, and multiple vertical frames 30, which divide rows adjacent to any row into multiple columns, are not arranged alternately, the arrangement of multiple cells, which will be described later, becomes a linear array, thereby inducing directionality in the flat panel speaker.

[0047] That is, since the multiple vertical frames 30 that divide any row into multiple columns and the multiple vertical frames 30 that divide the row adjacent to any row into multiple columns are arranged alternately, the sound waves generated in each grid do not interfere with each other.

[0048] Multiple horizontal frames 20 and multiple vertical frames 30 can be fixed on the substrate 10, and the angle formed by each of the multiple horizontal frames 20 and each of the multiple vertical frames 30 can be a right angle.

[0049] Multiple piezoelectric elements 40 are provided on the sides of each of the multiple vertical frames 30, which contract and expand in a direction parallel to the horizontal frame (left-right direction) according to a voltage signal.

[0050] The piezoelectric element 40 refers to an element that has the following characteristics: when pressure is applied in a specific direction, positive and negative charges proportional to the external force are formed on both sides of the plate, or when a voltage is applied to both sides of the plate, it expands or contracts.

[0051] Multiple piezoelectric elements 40 can be arranged parallel to multiple vertical frames 30 and orthogonal to multiple horizontal frames 20, thereby contracting and expanding in a direction parallel to the horizontal frames 20 according to a voltage signal applied from the electrode 45.

[0052] The height of each of the plurality of horizontal frames 20, the height of each of the plurality of vertical frames 30, and the height of each of the plurality of piezoelectric elements 40 disposed on the substrate 10 can be the same, thereby effectively forming the plurality of holes described below.

[0053] Multiple electrodes 45 may be disposed on both sides of each of the multiple piezoelectric elements 40 to apply a voltage signal to the piezoelectric element 40.

[0054] Such a plurality of electrodes 45 may include a first electrode 45-1 disposed between one side of the vertical frame 30 and one side of the piezoelectric element 40, and a second electrode 45-2 disposed on the other side of the piezoelectric element 40. One of the first electrode 45-1 or the second electrode 45-2 may be grounded, and the other electrode may be subject to a control voltage. The plurality of piezoelectric elements 40 and the plurality of horizontal frames 20 may form a plurality of independent cells (C). In this case, the plurality of cells C may represent empty spaces in which the front, back, left, right, and bottom sides are blocked.

[0055] Therefore, the spacing between the multiple horizontal frames 20 can be the same as the width of the multiple piezoelectric elements 40 and the width of the multiple vertical frames 30.

[0056] For example, an empty space surrounded by the piezoelectric element 40 disposed on the right side of the first vertical frame 30a-1, the piezoelectric element 40 disposed on the left side of the second vertical frame 30a-2, the first horizontal frame 20-1 and the second horizontal frame 20-2 can be formed on the substrate 10, and this empty space is referred to as a lattice C.

[0057] The volume of the multiple pores C can be changed according to the contraction and expansion of the piezoelectric element 40.

[0058] Reference Figure 4 When the piezoelectric element 40 forming any one of the multiple pores C1 is referred to as the first piezoelectric element 40-1 and the second piezoelectric element 40-2, if the first piezoelectric element 40-1 and the second piezoelectric element 40-2 expand simultaneously, the volume of the pore C1 may decrease.

[0059] For example, when the first electrode 45-1 is grounded and a voltage signal is applied from the controller 50 to the second electrode 45-2, the controller 50 can control the first piezoelectric element 40-1 and the second piezoelectric element 40-2 to expand simultaneously by applying a positive voltage to the second electrode 45-2.

[0060] In this case, each of the first piezoelectric element 40-1 and the second piezoelectric element 40-2 expands by dV, thereby reducing the volume of the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 by 2dV. That is, the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 can contract in response to the application of a positive voltage to the first piezoelectric element 40-1 and the second piezoelectric element 40-2.

[0061] As the volume of the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 decreases, the air inside the lattice C1 is expelled.

[0062] Reference Figure 5 When the piezoelectric element 40 that forms any one of the multiple pores C1 is referred to as the first piezoelectric element 40-1 and the second piezoelectric element 40-2, if the first piezoelectric element 40-1 and the second piezoelectric element 40-2 shrink at the same time, the volume of the pore C1 may increase.

[0063] For example, when the first electrode 45-1 is grounded and a voltage signal is applied from the controller 50 to the second electrode 45-2, the controller 50 can control the first piezoelectric element 40-1 and the second piezoelectric element 40-2 to contract simultaneously by applying a negative voltage to the second electrode 45-2.

[0064] In this case, each of the first piezoelectric element 40-1 and the second piezoelectric element 40-2 contracts by dV, thereby increasing the volume of the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 by 2dV. That is, the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 can expand in response to the application of a negative voltage to the first piezoelectric element 40-1 and the second piezoelectric element 40-2.

[0065] As the volume of the lattice C1 formed by the first piezoelectric element 40-1 and the second piezoelectric element 40-2 increases, air outside the lattice C1 is introduced into the lattice.

[0066] In this way, when the controller 50 repeatedly applies positive and negative voltages to the second electrode 45-2, the process of air being discharged to the outside of the aperture C1 and air flowing into the aperture is repeated, thereby generating sound waves.

[0067] The controller 50 can output the user's desired sound by adjusting the intensity and frequency of the voltage applied to the second electrode 45-2 based on the sound signal received from an external device.

[0068] For example, controller 50 can adjust the intensity and frequency of the voltage applied to the second electrode 45-2 based on sound signals such as music, video and navigation sounds output from the vehicle's AVN device.

[0069] Therefore, the controller 50 may include at least one memory for storing programs for performing the operations described above and below, and at least one processor for executing the stored programs.

[0070] When the controller 50 includes multiple memories and multiple processors, the multiple memories and multiple processors can be directly integrated into a single chip, or they can be physically separated.

[0071] exist Figure 3 The diagram shows a controller 50 connected to each electrode 45, but the controller 50 may be connected to a substrate 10, and the substrate 10 may be connected to each electrode to apply a voltage signal to each electrode based on a control signal from the controller 50.

[0072] As described above, assuming that a grid, two piezoelectric elements forming a grid, and four electrodes disposed on the two piezoelectric elements constitute a sound output unit, then a flat panel loudspeaker according to an exemplary embodiment may include multiple sound output units.

[0073] The controller 50 can independently control each of the multiple sound output units.

[0074] Specifically, the plurality of piezoelectric elements 40 may include a first piezoelectric element forming a first hole in a plurality of holes C and a second piezoelectric element forming a second hole, and the controller 50 may control the voltage applied to the plurality of electrodes 45 such that the voltage level applied to the first piezoelectric element is greater than the voltage level applied to the second piezoelectric element.

[0075] Relative to a first sound output unit including a first piezoelectric element forming a first aperture and a second sound output unit including a second piezoelectric element forming a second aperture, the controller 50 can independently apply voltage to the electrodes disposed in the first piezoelectric element and the electrodes disposed in the second piezoelectric element to output sounds with different sound pressure levels.

[0076] Reference Figure 6 The voltage applied to the piezoelectric element forming the first aperture C11 can be less than the voltage applied to the piezoelectric element forming the second aperture C22, and the voltage applied to the piezoelectric element forming the second aperture C22 can be less than the voltage applied to the piezoelectric element forming the third aperture C33.

[0077] Similarly, the voltage applied to the piezoelectric element forming the fourth pore C13 can be less than the voltage applied to the piezoelectric element forming the fifth pore C23, and the voltage applied to the piezoelectric element forming the fifth pore C23 can be less than the voltage applied to the piezoelectric element forming the third pore C33.

[0078] That is, the controller 50 can apply a larger voltage to the piezoelectric element that forms a grid of holes closer to the center of the substrate 10.

[0079] The sound output unit closer to the center of the substrate 10 outputs sound with a higher sound pressure level, and the sound waves generated from the flat panel speaker are arranged in a Gaussian distribution, thereby producing sound directivity and reducing sound wave cancellation.

[0080] Figure 6 The sound pressure level distribution shape shown is merely an example, and according to embodiments, the sound pressure level distribution shape can be set differently. As an example, the controller 50 can implement a directional steering technique for generating sound waves by independently controlling each sound output unit.

[0081] According to an exemplary embodiment, the flat panel speaker can be attached to the interior of a vehicle, and therefore, various sounds can be output inside the vehicle.

[0082] Furthermore, the disclosed embodiments can be implemented in the form of a recording medium storing computer-executable instructions. The instructions can be stored as program code, and when executed by a processor, the instructions can generate program modules to perform the operations of the disclosed embodiments. The recording medium can be implemented as a computer-readable recording medium.

[0083] Computer-readable recording media include various recording media in which instructions that can be decoded by a computer are stored, such as read-only memory (ROM), random access memory (RAM), magnetic tape, magnetic disk, flash memory, optical data storage devices, etc.

[0084] Although exemplary embodiments of the invention have been described for illustrative purposes, those skilled in the art will understand that various modifications, additions, and substitutions can be made without departing from the scope and spirit of the invention. Therefore, the described exemplary embodiments of the invention are not intended to be limiting.

Claims

1. A flat panel speaker, comprising: substrate; Multiple horizontal frames are disposed on the substrate and divide the substrate into multiple rows; Multiple vertical frames are arranged on the substrate, and each of the multiple rows is divided into multiple columns; Multiple piezoelectric elements are disposed on the side of each of the multiple vertical frames and contract and expand according to a voltage signal; Multiple electrodes apply voltage signals to the piezoelectric element; as well as The controller controls the voltage signals applied to the plurality of electrodes. The plurality of piezoelectric elements and the plurality of horizontal frames form a plurality of independent holes on the substrate; The plurality of piezoelectric elements contract and expand in a direction parallel to the horizontal frame according to the voltage signal, thereby changing the volume of the plurality of apertures, and the volume change of the plurality of apertures generates sound waves; and Each of the plurality of cells is surrounded by piezoelectric elements between adjacent vertical frames and adjacent horizontal frames, forming empty spaces blocked on the front, back, left, right and bottom sides.

2. The flat panel speaker according to claim 1, wherein, The plurality of vertical frames include a plurality of first vertical frames that divide any one of the plurality of rows into a plurality of columns and a plurality of second vertical frames that divide another row adjacent to the stated row into a plurality of columns, wherein the plurality of first vertical frames and the plurality of second vertical frames are arranged alternately.

3. The flat panel speaker according to claim 1, wherein, The plurality of electrodes are disposed on both sides of each of the plurality of piezoelectric elements.

4. The flat panel speaker according to claim 1, wherein, The plurality of piezoelectric elements includes a first piezoelectric element and a second piezoelectric element forming any one of the plurality of apertures; and The controller controls the voltage applied to the plurality of electrodes, causing the first piezoelectric element and the second piezoelectric element to expand and contract simultaneously.

5. The flat panel speaker according to claim 4, wherein, Any one of the plurality of pores expands in response to a positive voltage applied to the first piezoelectric element and the second piezoelectric element, and contracts in response to a negative voltage applied to the first piezoelectric element and the second piezoelectric element.

6. The flat panel speaker according to claim 2, wherein, The plurality of piezoelectric elements includes a first piezoelectric element forming a first cavity in the plurality of pores and a second piezoelectric element forming a second cavity; and The controller controls the voltage applied to the plurality of electrodes such that the voltage applied to the first piezoelectric element is greater than the voltage applied to the second piezoelectric element.

7. The flat panel speaker according to claim 6, wherein, The first aperture is positioned closer to the center of the substrate than the second aperture.

8. The flat panel speaker according to claim 1, wherein, The height of each of the plurality of horizontal frames, the height of each of the plurality of vertical frames, and the height of each of the plurality of piezoelectric elements are the same.

9. The flat panel speaker according to claim 1, wherein, The spacing between each of the plurality of horizontal frames is equal to the width of each of the plurality of vertical frames and the width of each of the plurality of piezoelectric elements.

10. The flat panel speaker according to claim 1, wherein, The flat panel speaker is installed in the vehicle.

11. A vehicle comprising: Audio and video navigation, also known as AVN devices; as well as Flat panel speakers, including: Multiple horizontal frames are disposed on a substrate, dividing the substrate into multiple rows; Multiple vertical frames are arranged on the substrate, and each of the multiple rows is divided into multiple columns; Multiple piezoelectric elements are disposed on the side of each of the multiple vertical frames and contract and expand according to a voltage signal; Multiple electrodes apply voltage signals to the piezoelectric element; and The controller, based on the sound signal output from the AVN device, controls the intensity and frequency of the voltage applied to the plurality of electrodes. The plurality of piezoelectric elements and the plurality of horizontal frames form a plurality of independent holes on the substrate; The plurality of piezoelectric elements contract and expand in a direction parallel to the horizontal frame according to the voltage signal, thereby changing the volume of the plurality of apertures, and the volume change of the plurality of apertures generates sound waves; and Each of the plurality of cells is surrounded by piezoelectric elements between adjacent vertical frames and adjacent horizontal frames, forming empty spaces blocked on the front, back, left, right and bottom sides.

12. The vehicle according to claim 11, wherein, The plurality of vertical frames include a plurality of first vertical frames that divide any one of the plurality of rows into a plurality of columns and a plurality of second vertical frames that divide another row adjacent to the stated row into a plurality of columns, wherein the plurality of first vertical frames and the plurality of second vertical frames are arranged alternately.

13. The vehicle according to claim 11, wherein, The plurality of electrodes are disposed on both sides of each of the plurality of piezoelectric elements.

14. The vehicle according to claim 11, wherein, The height of each of the plurality of horizontal frames, the height of each of the plurality of vertical frames, and the height of each of the plurality of piezoelectric elements are the same.

15. The vehicle according to claim 11, wherein, The spacing between each of the plurality of horizontal frames is equal to the width of each of the plurality of vertical frames and the width of each of the plurality of piezoelectric elements.

16. A flat panel speaker, comprising: Multiple horizontal frames are disposed on a substrate, dividing the substrate into multiple rows; Multiple vertical frames are arranged on the substrate, and each of the multiple rows is divided into multiple columns; Multiple piezoelectric elements are disposed on the side of each of the multiple vertical frames and contract and expand according to a voltage signal; Multiple electrodes apply voltage signals to the piezoelectric element; as well as The controller controls the voltage signals applied to the plurality of electrodes; The plurality of piezoelectric elements and the plurality of horizontal frames form a plurality of independent holes on the substrate; and The plurality of piezoelectric elements contract and expand in a direction parallel to the horizontal frame according to the voltage signal, thereby changing the volume of the plurality of pores, and the volume change of the plurality of pores generates sound waves; and Each of the plurality of cells is surrounded by piezoelectric elements between adjacent vertical frames and adjacent horizontal frames, forming empty spaces blocked on the front, back, left, right and bottom sides.

17. The flat panel speaker according to claim 16, wherein, The plurality of piezoelectric elements includes a first piezoelectric element and a second piezoelectric element forming any one of the plurality of apertures; and The controller controls the voltage applied to the plurality of electrodes, causing the first piezoelectric element and the second piezoelectric element to expand and contract simultaneously.

18. The flat panel speaker according to claim 17, wherein, Any one of the plurality of pores expands in response to a positive voltage applied to the first piezoelectric element and the second piezoelectric element, and contracts in response to a negative voltage applied to the first piezoelectric element and the second piezoelectric element.

19. The flat panel speaker according to claim 16, wherein, The plurality of piezoelectric elements include a first piezoelectric element forming a first cavity in the plurality of cavity grids and a second piezoelectric element forming a second cavity grid; The first aperture is positioned closer to the center of the substrate than the second aperture; and The controller controls the voltage applied to the plurality of electrodes such that the voltage applied to the first piezoelectric element is greater than the voltage applied to the second piezoelectric element.

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