JP2009278377A - Sounding body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sounding body having excellent acoustic characteristics even when a low conductive electrode material is used. <P>SOLUTION: The sounding body 1A includes a sheet-like vibration part 2 which expands and contracts or operates depending on electric field intensity and is formed of elastomer or piezoelectric polymer, a pair of electrodes 3a, 3b arranged on both surfaces of the vibration part 2 and formed of conductive polymer which generates the electric field intensity, and electrode terminals 4 arranged on the electrodes 3a, 3b. The vibration part 2 is so structured that a thickness of the vibration part 2 is reduced as distances from the electrode terminals 4 increase. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sounding body used for a speaker.

  Development of highly realistic sound devices intended for use in home environments such as SHV (Super Hi-Vision) has been actively conducted. In general, a certain number of speakers are often required to realize high realistic sound. However, a method of installing a large number of speakers in a living room or the like is not familiar with the current living environment. Therefore, it is desired to provide a thin and lightweight speaker and a sounding body used for the speaker.

  Conventionally, as a sounding body used for a thin and lightweight speaker, Patent Document 1 discloses a sheet-like composite piezoelectric material made of a flexible resin (for example, polyurethane resin) and a piezoelectric element (for example, lead titanium zirconate ceramic). A diaphragm (a sound producing body in the present invention) in which electrodes (for example, an aluminum film) are provided on both sides of the body is described. In Patent Document 2, a piezoelectric material including a ferroelectric composite oxide (for example, lead zirconate titanate ceramic) having a predetermined dielectric constant, and electrodes (for example, a silver film) formed on both surfaces of the piezoelectric material are disclosed. Is a thin plate piezoelectric element (sound-producing body in the present invention).

  In recent years, the development of sounding bodies using elastomers based on silicon or acrylic or the like has been promoted instead of piezoelectric bodies or piezoelectric materials (hereinafter referred to as piezoelectric bodies) using ceramics or the like. The elastomer has rubber-like flexibility in the air as compared to the piezoelectric body, and is easy to process because there is no restriction on the shape, and transparency can be realized by selecting the type of resin. Because of its advantages, it is suitable for the development of relatively large area sound generators. In addition, a sounding body using PVDF (polyvinylidene fluoride) instead of a titanium zirconate-based ceramic as the above-described piezoelectric body has been developed. PVDF, like elastomers, has the advantage of being excellent in flexibility, transparency and processability, and is therefore suitable for the development of a relatively large area sounding body.

In the sounding body using the above-described elastomer, an attractive force is generated between the electrodes due to Maxwell stress generated by voltage application. And by this attractive force, an elastomer is compressed and the thickness changes. At this time, by superimposing an audio signal on an appropriate DC bias voltage, the elastomer vibrates by expanding and contracting in all directions according to the voltage value, and a sound is generated.
JP 08-88896 (Claim 1, paragraph 0009, FIG. 1) JP 2001-57449 A (Claim 1, paragraph 0026, paragraph 0031, FIG. 1)

  However, in the sounding body using the above-described elastomer, it is necessary to form metal electrodes on both sides of the elastomer by a method such as vapor deposition in order to apply a voltage. When a voltage is applied to the sounding body, since the elastomer is flexible and has a large expansion / contraction width, the metal electrode may obstruct the deformation operation of the elastomer.

  Therefore, the use of a flexible electrode made of a conductive polymer instead of a metal electrode has been studied. And with the progress of development in recent years, many conductive polymers exhibiting high conductivity have come to be known. However, in comparison with a metal electrode, an electrode made of a conductive polymer remains low in conductivity at present. For this reason, when a voltage is distributed to a large-area electrode, a voltage drop corresponding to the distance from the electrode terminal cannot be avoided. In general, since the elastomer is also configured with a uniform thickness, as a result, the electric field strength between the electrodes decreases according to the distance from the electrode terminal. Since the attractive force between the electrodes is proportional to the electric field strength, the degree of expansion / contraction (vibration) of the elastomer generated by the attractive force between the electrodes decreases according to the distance from the electrode terminal. As a result, there is a problem that the entire surface of the sounding body (elastomer) is less likely to vibrate equally and the acoustic characteristics are degraded. Similarly, even in a sounding body using PVDF that vibrates according to the electric field strength, a reduction in electric field strength due to a voltage drop according to the distance from the electrode terminal cannot be avoided, and the entire surface of the sounding body (PVDF) vibrates equally. There is a problem that the acoustic characteristics are deteriorated.

  Therefore, the present invention was devised to solve such problems, and its purpose is to provide a sounding body having excellent acoustic characteristics even when an electrode material with low conductivity is used. is there.

  In order to solve the above-mentioned problem, a sounding body according to claim 1 is provided with a sheet-like vibration part made of an elastomer or a piezoelectric polymer that expands or contracts according to electric field strength, and is provided on both surfaces of the vibration part. A sounding body comprising a pair of electrodes made of a conductive polymer that generates strength, and an electrode terminal provided on the electrode, wherein the vibrating portion of the vibrating portion increases as the distance from the electrode terminal increases. It is characterized in that the thickness is reduced.

  According to the above configuration, when the vibration part is configured such that the thickness of the vibration part becomes thin as the distance from the electrode terminal increases, a voltage drop corresponding to the distance from the electrode terminal occurs in the voltage between the electrodes. Even so, since the distance between the electrodes decreases according to the distance from the electrode terminals, the electric field strength is constant at each point of the electrodes. As a result, the entire surface of the sounding body (vibrating part) vibrates uniformly.

  The sounding body according to claim 2, wherein the vibration part is formed in a rectangular shape, is provided along two sides facing the electrode terminal, and the vibration part is provided on at least one of both surfaces of the vibration part. The concave portion is formed so that the thickness of the vibration portion decreases from the two sides of the portion toward the center.

  According to the said structure, even if the voltage drop according to the distance from an electrode terminal generate | occur | produces in the voltage between electrodes because the vibration part is provided with the recessed part, it is the vibration part of the vibration part toward the center from two facing sides. Since the thickness is reduced and the distance between the electrodes is reduced, the electric field strength is constant at each point of the electrodes. As a result, the entire surface of the sounding body (vibrating part) vibrates uniformly.

  The sounding body according to claim 3, wherein the vibrating portion is formed in a circular or elliptical shape, the electrode terminal is provided along a peripheral edge, and the vibrating portion is provided on at least one of both surfaces of the vibrating portion. The concave portion is formed so that the thickness of the vibration portion becomes thinner from the peripheral edge toward the center.

  According to the said structure, even if the voltage drop according to the distance from an electrode terminal generate | occur | produces in the voltage between electrodes because the vibration part is provided with the recessed part, the thickness of a vibration part becomes thin toward a center from a periphery. Thus, since the distance between the electrodes becomes small, the electric field strength is constant at each point of the electrodes. As a result, the entire surface of the sounding body (vibrating part) vibrates uniformly.

  A sounding body according to a fourth aspect is a sounding body in which two sounding bodies according to any one of the first to third aspects are stacked and a DC voltage is applied between the electrodes. The electrodes are stacked such that the electrodes on the high potential output side of the electrodes face each other.

  According to the above configuration, since the sounding body is a laminate of two sounding bodies, the sounding body vibration part is divided into two parts, and the thickness of each sounding body vibration part is reduced. When a direct current is applied to, the voltage applied to each sounding body can be lowered. As a result, it is possible to prevent an electric shock due to a high potential. In addition, since the two sounding bodies are laminated so that the electrodes on the high potential output side face each other, when a DC voltage is applied to the sounding body, only the electrode on the ground potential (0 V) output side is the sounding body. Therefore, it is possible to further prevent an electric shock due to a high potential.

  The sounding body according to claim 5 is characterized in that a plurality of the laminated bodies are laminated.

  According to the above-described configuration, the sounding body is obtained by further laminating a plurality of stacked bodies in which two sounding bodies are stacked so that the electrodes on the high potential output side face each other, so that there are four vibration portions of the sounding body. Dividing into the above, the thickness of the vibrating portion of each sounding body is further reduced, and when a DC voltage is applied to the sounding body, the voltage applied to each sounding body can be further reduced. In addition, it is possible to further prevent electric shock due to a high potential. Furthermore, since the sounding body is composed of a plurality of laminated bodies (two sounding bodies), it is possible to efficiently increase the amplitude of the entire sounding body.

  A sounding body according to claim 6 is a sounding body in which a plurality of sounding bodies according to any one of claims 1 to 3 are stacked and an AC voltage is applied between the electrodes, An insulating portion is provided between the electrodes of the sounding body.

  According to the above-described configuration, the sounding body is a laminate of a plurality of sounding bodies, and includes an insulating portion between the electrodes of adjacent sounding bodies, so that the vibration portion of the sounding body is divided into a plurality of parts. The thickness of the vibrating portion of each sounding body is reduced, and when an AC voltage is applied to the sounding body, the voltage applied to each sounding body can be lowered. As a result, it is possible to prevent an electric shock due to a high potential. In addition, since the sounding body is composed of a plurality of sounding bodies, it is possible to efficiently increase the amplitude of the entire sounding body.

  According to the sounding body according to claims 1 to 3, since the electric field strength of the vibration part is constant and the entire surface of the vibration part vibrates uniformly, the acoustic characteristics are excellent. And the sounding body in which the vibration part is formed in a rectangular shape and the electrode terminals are provided on the two sides facing each other, or the sounding body in which the vibration part is formed in a circle or an ellipse and the electrode terminal is provided on the periphery thereof In this case, the acoustic characteristics are particularly excellent.

  According to the sounding bodies according to claims 4 to 6, the sound characteristics are excellent, and the voltage applied to each sounding body is reduced, so that the economy and safety are excellent. Further, according to the sounding body of claims 4 and 5 to which a DC voltage is applied, since only the electrode on the ground potential output side is exposed to the outside of the sounding body, electric shock due to a high potential is further prevented. Safety is even better.

  The sounding body according to claims 1 to 6 is suitably used for a thin and lightweight speaker that can be flexibly adapted to the home environment.

Embodiments of a sounding body according to the present invention will be described in detail with reference to the drawings.
Here, FIG. 1A is a perspective view showing the configuration of the sounding body, FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A, FIG. 1C is a cross-sectional view showing the configuration of the modification, and FIG. ) Is a change in potential difference in the sounding body of FIG. 1, (b) is a change in thickness, (c) is a view showing a change in electric field strength, and FIG. 3 (a) is a perspective view showing a configuration of another embodiment of the sounding body. FIG. 4B is a cross-sectional view taken along the line BB of FIG. 4A, FIG. 4C is a cross-sectional view illustrating a configuration of a modified example, FIG. 4A is a change in potential difference in the sounding body of FIG. A change in thickness, (c) is a diagram showing a change in electric field strength.

As shown in FIGS. 1A and 1B, the sounding body 1A includes a vibrating portion 2, a pair of electrodes 3a and 3b, and an electrode terminal 4, and the vibrating portion 2 includes a recess 5a.
The vibration part 2 is composed of a sheet made of an elastomer or piezoelectric polymer that expands or contracts according to the electric field strength generated when a voltage is applied to the pair of electrodes 3a and 3b. The elastomer is preferably polyurethane, natural rubber, polypropylene, polybutylene terephthalate, etc., and the piezoelectric polymer is preferably PVDF or a composite thereof, but other than the above as long as it has excellent flexibility, moldability and high temperature durability. It may be. In addition, when the sounding body 1A is required to be transparent, it is preferable to select an elastomer or a piezoelectric polymer having excellent transparency.

  The vibrating part 2 is configured such that the thickness of the vibrating part 2 decreases as the distance L from the electrode terminal 4 provided on the electrodes 3a and 3b increases. As for the thickness of the vibration part 2, it is preferable to set the thickness T1 at the end that is the maximum thickness to about 200 μm in order to meet the demand for a thinner and lighter sounding body 1A. The thickness T2 at the bottom of the concave portion 5a that is the minimum thickness is set in consideration of a voltage drop according to the distance L from the electrode terminal 4, and is specifically about 195 μm in an area of 297 mm × 210 mm.

  The electrodes 3a and 3b are sheet-like electrodes that are provided on both surfaces of the vibration unit 2 and are made of a conductive polymer that generates a predetermined electric field strength between the electrodes 3a and 3b. As the conductive polymer, a polymer having a resistivity of 3 kΩ / □ or less, for example, polyethylene dioxythiophene is preferable, but any other polymer may be used as long as it has excellent conductivity and flexibility. Good. Moreover, when transparency is desired for the sounding body 1A, it is preferable to select a conductive polymer having excellent transparency. Further, the thickness of the electrodes 3a and 3b is preferably about 1 μm which does not inhibit the vibration of the vibration part 2, and is formed on both surfaces of the vibration part 2 by a spin coating method or the like.

  The electrode terminal 4 is a conducting wire or the like for applying a high voltage between the electrode 3a and the electrode 3b, and may be provided at the end of the electrodes 3a and 3b so as not to inhibit the vibration of the vibration unit 2. preferable. The connection between the electrodes 3a and 3b and the electrode terminal 4 (conductive wire) may be a point contact, but a line contact as shown in FIG.

Next, a preferred embodiment of the sounding body will be described.
As shown in FIGS. 1A and 1B, the sounding body 1A has a vibrating portion 2 formed in a rectangular shape, provided along two sides facing the electrode terminal 4, and a vibrating portion. 2 is preferable in which the concave portion 5a is formed so that the thickness of the vibrating portion 2 becomes thinner from the two sides toward the center. Specifically, the concave portion 5a is constituted by a flat inclined surface 6a with the center of the vibration portion 2 as a valley. The details of the vibrating portion 2, the electrode 3a (3b), and the electrode terminal 4 are as described above. Further, as shown in FIG. 1C, the sounding body 1 </ b> A may be one in which concave portions 5 a are formed on both surfaces of the vibrating portion 2.

  In the sounding body 1A, changes in potential difference, thickness (vibration unit 2), and electric field strength are as follows. Further, assuming that the conductivity of the electrodes 3a and 3b is p, the length of the vibrating portion 2 (distance from the electrode terminal 4) is L, and the cross-sectional area of the electrodes 3a and 3b is S, the resistance R of the electrodes 3a and 3b is R = It can be expressed as pL / S.

As shown in FIG. 2A, the potential difference is the distance from the electrode terminal 4 because the electrode terminal 4 of the sounding body 1A is provided along the two sides facing the vibrating portion 2 (electrodes 3a and 3b). It is expressed as a linear function of L, and changes linearly (voltage drop) with the center of the vibration part 2 as a valley.
As shown in FIG. 2B, the thickness (vibrating part 2) is expressed as a linear function of the distance L, like the potential difference, and changes linearly with the center of the vibrating part 2 as a valley.
As shown in FIG. 2C, the electric field strength is always constant. This is because the potential decreases at the center of the vibration part 2 (see FIG. 2A), but the thickness of the vibration part 2 similarly decreases at the center (see FIG. 2B).

  As shown in FIGS. 3A and 3B, the sounding body 1 </ b> B has the vibrating portion 2 formed in a circular or elliptical shape, the electrode terminals 4 provided along the periphery, and the vibrating portion 2. What formed the recessed part 5b so that the thickness of the vibration part 2 may become thin toward the center from the periphery of is preferable. Specifically, the concave portion 5b is configured by a curved inclined surface 6b with the center of the vibrating portion 2 as a valley. The details of the vibrating portion 2, the electrode 3a (3b), and the electrode terminal 4 are as described above. Further, as shown in FIG. 3C, the sounding body 1 </ b> B may be one in which concave portions 5 b are formed on both surfaces of the vibrating portion 2.

  In sounding body 1B, changes in potential difference, thickness (vibrating portion 2), and electric field strength are as follows. Further, the resistance R of the electrodes 3a and 3b can be expressed by R = pL / S as in the sounding body 1A.

As shown in FIG. 4 (a), since the electrode terminal 4 of the sounding body 1B is provided along the periphery of the vibrating portion 2 (electrodes 3a and 3b), the potential difference is defined by using the center of the vibrating portion 2 as a valley. It changes logarithmically with respect to the distance L from the electrode terminal 4 (voltage drop).
As shown in FIG. 4B, the thickness (vibrating portion 2) changes logarithmically with respect to the distance L with the center of the vibrating portion 2 as a valley, similarly to the potential difference.
As shown in FIG. 4C, the electric field strength is always constant. This is because the potential decreases at the center of the vibration part 2 (see FIG. 4A), but the thickness of the vibration part 2 similarly decreases at the center (see FIG. 4B).

  Therefore, in the sounding members 1A and 1B, by forming the recesses 5a and 5b in the vibration part 2, the electric field strength that decreases due to the voltage drop is compensated by reducing the thickness of the vibration part 2, and Since the electric field strength at each point can be made constant, the entire surface of the vibration part 2 vibrates uniformly, and the acoustic characteristics are excellent.

Next, another embodiment of the sounding body will be described with reference to the drawings. Here, FIGS. 5A and 5B are side views showing the configuration of another embodiment of the sounding body according to the present invention.
As shown in FIG. 5A, the sounding body 1C is composed of a laminated body 7 in which two sounding bodies 1A (1B) (see FIGS. 1A and 3A) are stacked, A DC voltage is applied between the electrode 3a and the electrode 3b, and the electrodes 3a and 3b are stacked so that the electrodes 3a on the high potential output side face each other. Further, the sounding body 1C may be a laminate of a plurality of laminated bodies 7. The number of sounding bodies 1A (1B) constituting the sounding body 1C is preferably 2 to 10, and the total thickness of the vibration parts 2 of the sounding body 1C is set to the end of the vibration part 2 of each sounding body 1A (1B). The total of the maximum thickness T1 of the part (see FIGS. 1B and 3B) is preferably about 200 μm. Further, it is preferable that the sounding body 1A (1B) is laminated by bonding the electrodes 3a with a conductive adhesive or the like. The details of the sounding body 1A (1B) are as described above.

  In the sounding body 1C, the electrodes 3a on the high potential output side are laminated so as to face each other, so that only the ground potential (0V) output side electrode 3b is exposed to the outside of the sounding body 1C. As a result, when the sounding body 1C is touched by mistake, it is possible to prevent an electric shock due to a high potential (for example, 1500 V). Further, since the sounding body 1C is composed of a plurality of sounding bodies 1A (1B), the thickness of the vibrating portion 2 of each sounding body 1A (1B) is reduced, and the voltage applied to each sounding body 1A (1B). It is economical because it can be lowered. Moreover, since the amplitude of the entire sounding body 1C can be efficiently obtained, the acoustic characteristics of the sounding body 1C are further improved.

  As shown in FIG. 5 (b), the sounding body 1D includes a plurality of sounding bodies 1A (1B) (see FIGS. 1 (a) and 3 (a)) which are stacked to form an electrode 3a and an electrode 3b. An AC voltage is applied between them, and an insulating portion 8 is provided between the electrodes 3b and 3a of the adjacent sounding body 1A (1B). And it is preferable that the vibration part 2 consists of piezoelectric polymers (PVDF etc.). The insulating portion 8 is made of a known insulating material, and a sheet having a thickness of about 1 μm is preferable. The number of sounding bodies 1A (1B) constituting the sounding body 1D is preferably 2 to 4, and the total thickness of the vibrating parts 2 of the sounding body 1D is set to the end of the vibrating part 2 of each sounding body 1A (1B). The total of the maximum thickness T1 (see FIGS. 1B and 3B) is preferably about 100 μm.

  The sounding body 1D is composed of a plurality of sounding bodies 1A (1B), and includes the insulating portion 8 between the sounding bodies 1A (1B), so that the thickness of the vibrating portion 2 of each sounding body 1A (1B) is reduced. Since the voltage applied to each sounding body 1A (1B) can be lowered, it is economical. Further, since the amplitude of the entire sounding body 1D can be efficiently obtained, the acoustic characteristics of the sounding body 1D are further improved.

  The best mode for carrying out the present invention has been described in detail with reference to the drawings. However, the present invention is not limited to the embodiment, and may be changed as appropriate without departing from the spirit of the present invention. Is possible.

  For example, the sounding bodies 1A and 1B described above (see FIGS. 1A to 1C and FIGS. 3A to 3C) change the thickness of the vibrating portion 2 by forming the concave portions 5a and 5b. However, as shown in FIGS. 6A to 6C and FIGS. 7A to 7C, the sounding body 1E in which the thickness of the vibrating portion 2 is changed by forming the convex portions 9a and 9b. 1F may be sufficient. Here, FIG. 6A is a perspective view showing the configuration of another embodiment of the sounding body, FIG. 6B is a sectional view taken along the line CC of FIG. 6A, and FIG. 7 (a) is a perspective view showing the configuration of another embodiment of the sounding body, (b) is a sectional view taken along the line DD of (a), and (c) is a sectional view showing a modification. In the sound generators 1E and 1F, the same components as those of the sound generators 1A and 1B are denoted by the same reference numerals.

  In the sounding body 1E, the vibrating portion 2 is formed in a rectangular shape, the electrode terminal 4 is provided in the center of the rectangular shape (between two sides facing each other), and two sides (ends) from the center of the vibrating portion 2 are provided. The convex part 9a is formed so that the thickness of the vibration part 2 becomes thinner toward the part. Specifically, the convex portion 9a is configured by a flat inclined surface 6a with the center of the vibration portion 2 as a mountain. And as for the thickness of the vibration part 2, it is preferable that thickness t2 in the top part of the convex part 9a used as the maximum thickness shall be about 200 micrometers, and thickness t1 in the edge part used as minimum thickness shall be about 195 micrometers in the area of 297 mm x 210 mm. Further, the sounding body 1E may be one in which convex portions 9a are formed on both surfaces of the vibrating portion 2. Further, in the sounding body 1E, although not shown, the potential difference and the thickness (vibration part 2) are expressed as a linear function of the length of the vibration part 2 (distance L from the electrode terminal 4). However, the electric field strength is always constant. Similar to the sounding members 1A and 1B, a plurality of sounding members 1E may be stacked.

  In the sounding body 1F, the vibrating part 2 is formed in a circular shape or an elliptical shape, the electrode terminal 4 is provided at the center of the vibrating part 2, and the vibrating part 2 extends from the center of the vibrating part 2 toward the periphery. The convex portion 9b is formed so as to be thin. Specifically, the convex portion 9 b is configured by a curved inclined surface 6 b with the center of the vibration portion 2 as a mountain. The thicknesses t1 and t2 of the vibration part 2 are preferably the same as those of the sounding body 1E (convex part 9a). Further, the sounding body 1 </ b> F may be one in which convex portions 9 b are formed on both surfaces of the vibrating portion 2. Further, in the sounding body 1F, although not shown, the potential difference and the thickness (vibration part 2) change logarithmically with respect to the distance L from the electrode terminal 4 with the center of the vibration part 2 as a mountain (vibration part 2). However, the electric field strength is always constant. Note that a plurality of sound generators 1F may be stacked as in the sound generators 1A and 1B.

(A) is a perspective view which shows the structure of the sounding body based on this invention, (b) is the sectional view on the AA line of (a), (c) is sectional drawing which shows the structure of a modification. (A) is a change in potential difference in the sounding body of FIG. 1, (b) is a change in thickness, and (c) is a diagram showing a change in electric field strength. (A) is a perspective view which shows the structure of another embodiment of the sounding body based on this invention, (b) is BB sectional drawing of (a), (c) is sectional drawing which shows the structure of a modification. is there. (A) is a change in potential difference in the sounding body of FIG. 3, (b) is a change in thickness, and (c) is a diagram showing a change in electric field strength. (A), (b) is a side view which shows the structure of another embodiment of the sounding body based on this invention. (A) is a perspective view which shows the structure of another embodiment of the sounding body based on this invention, (b) is CC sectional view taken on the line of (a), (c) is sectional drawing which shows the structure of a modification. is there. (A) is a perspective view which shows the structure of another embodiment of the sounding body based on this invention, (b) is the DD sectional view taken on the line of (a), (c) is sectional drawing which shows the structure of a modification. is there.

Explanation of symbols

1A, 1B, 1C, 1D, 1E, 1F Sounding body 2 Vibrating part 3a, 3b Electrode 4 Electrode terminal 5a, 5b Recessed part 6a, 6b Inclined surface 7 Laminated body 8 Insulating part 9a, 9b Convex part

Claims (6)

A sheet-like vibration part made of an elastomer or piezoelectric polymer that expands or contracts according to the electric field strength, a pair of electrodes made of a conductive polymer that is provided on both surfaces of the vibration part and generates the electric field strength, and the electrodes A sounding body comprising electrode terminals provided in
The sounding body, wherein the vibrating portion is configured such that the thickness of the vibrating portion decreases as the distance from the electrode terminal increases.   The vibrating part is formed in a rectangular shape, provided along two sides where the electrode terminal faces, and on at least one of both surfaces of the vibrating part from the two sides of the vibrating part toward the center. The sounding body according to claim 1, wherein the concave portion is formed so that the thickness of the vibration portion is reduced.   The vibrating part is formed in a circular or elliptical shape, the electrode terminals are provided along the periphery, and the vibration is applied to at least one of both surfaces of the vibrating part from the periphery of the vibrating part toward the center. The sounding body according to claim 1, wherein the concave portion is formed so that the thickness of the portion is reduced.   A sounding body comprising a laminate in which two sounding bodies according to any one of claims 1 to 3 are stacked, and a DC voltage is applied between the electrodes, A sounding body characterized by being laminated so that electrodes on the potential output side face each other.   The sounding body according to claim 4, wherein a plurality of the stacked bodies are stacked.   A sounding body in which a plurality of sounding bodies according to any one of claims 1 to 3 are stacked and an AC voltage is applied between the electrodes, and an insulating portion is provided between the electrodes of adjacent sounding bodies. A sounding body characterized by comprising

Images