JP5871751B2 - SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE - Google Patents

Description

  Embodiments of the disclosure relate to a sound generator, a sound generation device, and an electronic apparatus.

  Conventionally, an acoustic generator using a piezoelectric element is known (see, for example, Patent Document 1). Such an acoustic generator is configured to vibrate a diaphragm by applying a voltage to a piezoelectric element attached to the diaphragm to vibrate, and to output sound by actively utilizing resonance of the vibration.

  In addition, since such a sound generator can use a thin film such as a resin film for the diaphragm, it can be made thinner and lighter than a general electromagnetic speaker.

  In addition, when using a thin film for a diaphragm, the thin film is supported in a state in which a uniform tension is applied, for example, by being sandwiched from a thickness direction by a pair of frame members so as to obtain excellent acoustic conversion efficiency. Is required.

JP 2004-023436 A

  However, the conventional acoustic generator described above actively uses the resonance of the diaphragm that is uniformly tensioned, and therefore, in the frequency characteristics of the sound pressure, the peak (the portion where the sound pressure is higher than the surroundings) and the dip There is a problem that high quality sound quality is difficult to obtain due to the fact that the sound pressure is lower than the surrounding area.

  One embodiment of the present invention has been made in view of the above, and an object thereof is to provide an acoustic generator, an acoustic generator, and an electronic apparatus that can obtain a favorable frequency characteristic of sound pressure.

An acoustic generator according to an aspect of an embodiment includes an exciter, a substantially flat vibrating body, and a support . The exciter vibrates upon receiving an electrical signal. The vibrator is attached with the exciter, and vibrates with the exciter due to vibration of the exciter. The support supports the vibrating body. The vibrating body is provided with pores so as to be distributed along a boundary between the support body and the vibrating body in a plan view .

  According to one aspect of the embodiment, a favorable sound pressure frequency characteristic can be obtained.

FIG. 1A is a schematic plan view showing a schematic configuration of a basic sound generator. 1B is a cross-sectional view taken along line A-A ′ of FIG. 1A. FIG. 2 is a diagram illustrating an example of frequency characteristics of sound pressure. FIG. 3A is a schematic cross-sectional view showing the configuration of the sound generator according to the embodiment. FIG. 3B is a schematic diagram (part 1) illustrating an example of forming voids. FIG. 3C is a schematic diagram (part 2) illustrating an example of formation of voids. FIG. 3D is a schematic diagram (part 3) illustrating a void formation example. FIG. 3E is a schematic diagram (part 4) illustrating an example of formation of voids. FIG. 4A is a schematic plan view (part 1) illustrating a void distribution region. FIG. 4B is a schematic plan view (part 2) illustrating a void distribution region. FIG. 4C is a schematic plan view (part 3) illustrating a void distribution region. FIG. 5A is a schematic cross-sectional view (part 1) illustrating an example of distribution of voids. FIG. 5B is a schematic cross-sectional view (part 2) illustrating an example of distribution of voids. FIG. 5C is a schematic cross-sectional view (part 3) illustrating an example of distribution of voids. FIG. 6A is a diagram illustrating a configuration of the sound generation device according to the embodiment. FIG. 6B is a diagram illustrating a configuration of the electronic device according to the embodiment.

  Hereinafter, embodiments of a sound generator, a sound generator, and an electronic device disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  First, prior to the description of the sound generator 1 according to the embodiment, a schematic configuration of a basic sound generator 1 ′ will be described with reference to FIGS. 1A and 1B. 1A is a schematic plan view showing a schematic configuration of the acoustic generator 1 ′, and FIG. 1B is a cross-sectional view taken along line A-A ′ of FIG. 1A.

  For ease of explanation, FIGS. 1A and 1B illustrate a three-dimensional orthogonal coordinate system including a Z-axis having a vertically upward direction as a positive direction and a vertically downward direction as a negative direction. Such an orthogonal coordinate system may also be shown in other drawings used in the following description.

  In addition, in the following, with regard to a plurality of constituent elements, only one of the plurality of constituent elements may be assigned a reference numeral, and the other reference numerals may be omitted. In such a case, it is assumed that one with the reference numeral and the other have the same configuration.

  Moreover, in FIG. 1A, illustration of the resin layer 7 (described later) is omitted. For easy understanding, FIG. 1B greatly exaggerates the sound generator 1 ′ in the thickness direction (Z-axis direction).

  As shown in FIG. 1A, the sound generator 1 ′ includes a frame body 2, a diaphragm 3, and a piezoelectric element 5. As shown in FIG. 1A, in the following description, the case where there is one piezoelectric element 5 is illustrated, but the number of piezoelectric elements 5 is not limited.

  The frame body 2 is composed of two frame members having a rectangular frame shape and the same shape, and functions as a support body that supports the diaphragm 3 by sandwiching the peripheral edge portion of the diaphragm 3. The diaphragm 3 has a plate-like or film-like shape, and its peripheral portion is sandwiched and fixed by the frame 2 and is substantially flat in a state where tension is uniformly applied within the frame of the frame 2. Supported by

  A portion of the diaphragm 3 inside the inner periphery of the frame 2, that is, a portion of the diaphragm 3 that is not sandwiched between the frames 2 and can vibrate freely is referred to as a vibrating body 3 a. That is, the vibrating body 3 a is a portion that has a substantially rectangular shape within the frame of the frame body 2.

  The diaphragm 3 can be formed using various materials such as resin and metal. For example, the diaphragm 3 can be made of a resin film such as polyethylene or polyimide having a thickness of about 10 to 200 μm.

  Further, the thickness and material of the frame body 2 are not particularly limited, and can be formed using various materials such as metal and resin. For example, a stainless steel member having a thickness of about 100 to 1000 μm can be suitably used as the frame 2 because it has excellent mechanical strength and corrosion resistance.

  Although FIG. 1A shows the frame 2 in which the shape of the inner region is substantially rectangular, it may be a polygon such as a parallelogram, trapezoid, or regular n-gon. In the present embodiment, as shown in FIG.

  Further, in the above description, the case where the frame body 2 is configured by two frame members and the peripheral portion of the diaphragm 3 is sandwiched and supported by the two frame members is described as an example. It is not a thing. For example, the frame body 2 may be constituted by a single frame member, and the peripheral edge portion of the diaphragm 3 may be bonded and supported to the frame body 2.

  The piezoelectric element 5 is an exciter that is provided by being affixed to the surface of the vibrating body 3a and that excites the vibrating body 3a by receiving a voltage to vibrate.

  As shown in FIG. 1B, the piezoelectric element 5 includes, for example, a laminate in which piezoelectric layers 5a, 5b, 5c, and 5d made of four ceramic layers and three internal electrode layers 5e are alternately laminated, Surface electrode layers 5f and 5g formed on the upper and lower surfaces of the laminate, and external electrodes 5h and 5j formed on the side surfaces where the internal electrode layer 5e is exposed. The lead terminals 6a and 6b are connected to the external electrodes 5h and 5j.

  The piezoelectric element 5 has a plate shape, and the main surface on the upper surface side and the lower surface side has a polygonal shape such as a rectangular shape or a square shape. The piezoelectric layers 5a, 5b, 5c, and 5d are polarized as shown by arrows in FIG. 1B. In other words, polarization is performed such that the direction of polarization with respect to the direction of the electric field applied at a certain moment is reversed between one side and the other side in the thickness direction (Z-axis direction in the figure).

  When a voltage is applied to the piezoelectric element 5 via the lead terminals 6a and 6b, for example, at a certain moment, the piezoelectric layers 5c and 5d on the side bonded to the vibrating body 3a contract and the upper surface of the piezoelectric element 5 is compressed. The piezoelectric layers 5a and 5b on the side are deformed so as to extend. Therefore, by applying an AC signal to the piezoelectric element 5, the piezoelectric element 5 can bend and vibrate, and the vibrating body 3a can be bent.

  In addition, the main surface of the piezoelectric element 5 is joined to the main surface of the vibrating body 3a by an adhesive such as an epoxy resin.

  The materials constituting the piezoelectric layers 5a, 5b, 5c and 5d are conventionally used, such as lead-free piezoelectric materials such as PZT (lead zirconate titanate), Bi layered compounds, and tungsten bronze structure compounds. Piezoelectric ceramics can be used.

  Various metal materials can be used as the material of the internal electrode layer 5e. For example, when a metal component composed of silver and palladium and a ceramic component constituting the piezoelectric layers 5a, 5b, 5c, and 5d are contained, the piezoelectric layers 5a, 5b, 5c, and 5d and the internal electrode layer 5e Since the stress due to the difference in thermal expansion can be reduced, the piezoelectric element 5 free from stacking faults can be obtained.

  The lead terminals 6a and 6b can be formed using various metal materials. For example, if the lead terminals 6a and 6b are configured using flexible wiring in which a metal foil such as copper or aluminum is sandwiched between resin films, the height of the piezoelectric element 5 can be reduced.

  Further, as shown in FIG. 1B, the sound generator 1 ′ is disposed so as to cover the surfaces of the piezoelectric element 5 and the vibrating body 3 a within the frame 2, and is integrated with the vibrating body 3 a and the piezoelectric element 5. The resin layer 7 is further provided.

  The resin layer 7 is preferably formed using, for example, an acrylic resin so that the Young's modulus is about 1 MPa to 1 GPa. In addition, since the moderate damping effect can be induced by embedding the piezoelectric element 5 in the resin layer 7, the resonance phenomenon can be suppressed, and the peak and dip in the frequency characteristic of the sound pressure can be suppressed small.

  FIG. 1B shows a state in which the resin layer 7 is formed so as to be the same height as the frame 2, but it is sufficient that the piezoelectric element 5 is embedded, for example, the resin layer 7 has a frame. It may be formed to be higher than the height of the body 2.

  In FIG. 1B, the piezoelectric element 5 is a bimorph multilayer piezoelectric element. However, the piezoelectric element 5 is not limited to this. For example, a unimorph type in which the expanding and contracting piezoelectric element 5 is attached to the vibrating body 3a. It does not matter.

  By the way, as shown in FIGS. 1A and 1B, the vibrating body 3 a is supported substantially flat in a state where tension is uniformly applied in the frame of the frame body 2. In such a case, since a peak dip or distortion due to resonance induced by vibration of the piezoelectric element 5 occurs, the sound pressure changes rapidly at a specific frequency, and it is difficult to flatten the frequency characteristic of the sound pressure.

  This point is illustrated in FIG. FIG. 2 is a diagram illustrating an example of frequency characteristics of sound pressure. As already described in the description of FIG. 1A, the vibrating body 3 a is supported substantially flat in a state where tension is uniformly applied within the frame of the frame body 2. Therefore, it can be said that the vibrating body 3a has a uniform Young's modulus as a whole.

  However, in such a case, since the peak concentrates on a specific frequency due to resonance of the vibrating body 3a and degenerates, steep peaks and dips are likely to be scattered throughout the entire frequency region as shown in FIG.

  As an example, attention is paid to a portion surrounded by a broken closed curve PD in FIG. When such a peak occurs, the sound pressure varies depending on the frequency, making it difficult to obtain good sound quality.

  In such a case, as shown in FIG. 2, the height of the peak P is lowered (see the arrow 201 in the figure), the peak width is widened (see the arrow 202 in the figure), and the peak P or dip (not shown) is reduced. It is effective to take measures to make it smaller.

  Therefore, in the present embodiment, by providing pores, so-called “voids”, to the vibrating body 3a, the vibrating body 3a is interspersed with regions having different Young's moduli so that the resonance frequencies are not partially aligned. did. As a result, the resonance mode degeneracy is solved and dispersed, the height of the peak P is lowered, and the peak width is widened.

  Hereinafter, the sound generator 1 according to the embodiment will be specifically described sequentially with reference to FIGS. 3A to 5C. First, FIG. 3A is a schematic cross-sectional view showing the configuration of the sound generator 1 according to the embodiment.

  For easy understanding, the size of the void V is exaggerated in the following drawings including FIG. 3A. In addition, in the following, including FIG. 3A, a schematic cross-sectional view may be shown, but all of them are assumed to be schematic cross-sectional views taken along the line A-A ′ of FIG. 1A.

  As shown in FIG. 3A, the sound generator 1 includes a void V in the vibrating body 3a in addition to the sound generator 1 'shown in FIGS. 1A and 1B. FIG. 3A illustrates a total of ten voids V, but the number is not limited.

  As an example of the size of the void V, it is preferable that the void V is smaller than half the thickness of the vibrating body 3a, assuming that the void V overlaps the thickness direction (Z-axis direction) of the vibrating body 3a. In addition, a typical example of the outer shape of the void V includes a circular shape, but other shapes may be used. In addition, the distribution form of the void V in the vibrating body 3a will be described later with reference to FIGS. 4A to 4C.

  Next, the formation example of the void V is demonstrated using FIG. 3B-FIG. 3E. 3B to 3E are schematic diagrams (No. 1) to (No. 4) showing examples of formation of the void V. FIG. FIG. 3C is an enlarged view of the portion M1 shown in FIG. 3B.

  As shown in FIG. 3B, the void V is, for example, configured such that the vibrating body 3 a is configured as a laminated body in which a plurality of diaphragms 3 are stacked, and in such a case, the void 3 is sandwiched between the diaphragms 3. Can be provided.

  Here, the intermediate layer 3b may be an adhesive layer that bonds the diaphragms 3 to each other. In such a case, for example, after using an epoxy resin two-component mixed adhesive, the void V can be provided by kneading the two components so as to entrain air.

  In this way, when the void V is provided in the intermediate layer 3b sandwiched between the diaphragms 3, the void V is provided as a so-called closed hole closed inside the vibrating body 3a.

  As described above, when the voids V are provided in the intermediate layer 3b, the voids V are distributed substantially parallel to the planar direction of the vibrating body 3a. That is, since regions having different Young's moduli can be scattered substantially parallel to the plane direction of the vibrating body 3a, the sound pressure peaks P of the resonance points vary on the surface and inside of the vibrating body 3a. The frequency characteristic can be flattened. Therefore, a favorable frequency characteristic of sound pressure can be obtained.

  The intermediate layer 3b is not limited to the adhesive layer. For example, a plate-like member having holes that can be used as pores, such as punching metal, may be sandwiched as the intermediate layer 3b.

  Further, as shown in FIG. 3C, the void V may be provided so as to darely contain a composition Va having a composition different from that of the vibrating body 3a. For example, by putting PVA (polyvinyl alcohol) together with the carbon powder of the pore material and curing it, the PVA can be left in the void V without being volatilized inside the void V.

  At this time, as shown in FIG. 3C, it is sufficient that at least a part of the inner wall of the void V is covered with the composition Va. As a result, regions having different Young's moduli can be interspersed inside the vibrating body 3a. Therefore, the sound pressure frequency characteristics of the sound pressure are varied by varying the sound pressure peak P at the resonance point on and inside the vibrating body 3a. It can be flattened. Therefore, a favorable frequency characteristic of sound pressure can be obtained.

  Moreover, as shown in FIG. 3D, the void V may be provided as an open pore opened on the surface of the vibrating body 3a. In such a case, the void V can be formed, for example, by using a shot blasting method in which an abrasive such as sand or dry ice is sprayed from the nozzle 70 as a projection material.

  Thus, by providing the voids V as open pores opened on the surface of the vibrating body 3a, regions having different Young's moduli can be scattered substantially parallel to the plane direction of the vibrating body 3a. It is possible to vary the sound pressure peak P at the resonance point on the surface and inside of the body 3a, and to flatten the frequency characteristic of the sound pressure. Therefore, a favorable frequency characteristic of sound pressure can be obtained.

  Further, when the void V is an open pore, the surface area of the vibrating body 3a can be increased, so that the sound propagation distance on the surface of the vibrating body 3a can be made different from the propagation distance inside. Therefore, the resonance of the vibrating body 3a can be smoothed, and the frequency characteristic of the sound pressure can be flattened.

  As shown in FIG. 3E, the void V may be provided by a combination of closed pores and open pores described so far. That is, they may be provided inside and on the surface of the vibrating body 3a. Moreover, as shown as M2 part in FIG. 3E, a plurality of voids V may be connected.

  Next, a distribution region that is a partial region of the vibrating body 3a in which the voids V are distributed will be described with reference to FIGS. 4A to 4C. 4A to 4C are schematic plan views (No. 1) to (No. 3) showing the distribution region of the void V. FIG.

  In addition, illustration of the void V is abbreviate | omitted in FIG. 4A-FIG. 4C. In FIGS. 4A to 4C, the distribution area of the void V is clearly shown as a hatched area filled with diagonal lines, but actually, the voids V are scattered and provided in the entire area of the vibrating body 3a. Therefore, the hatched area clearly shown in FIGS. 4A to 4C is an area provided so that the voids V are distributed more than the other partial areas of the vibrating body 3a.

  First, the void V is preferably provided in the vicinity of the piezoelectric element 5. This is because the stress generated by the vibration of the vibration source can be concentrated in the vicinity of the void V by providing more voids V in the vicinity of the piezoelectric element 5 that is the vibration source.

  Thereby, since the local distortion of the vicinity of the void V can be enlarged, a part of energy generated by the vibration can be absorbed by the void V, and the vibration can be effectively lost. Therefore, the resonance of the vibrating body 3a can be made smooth, and the frequency characteristic of the sound pressure can be flattened.

  Here, the “vicinity” of the piezoelectric element 5 will be specifically described. As shown as a hatched area in FIG. 4A, the voids V are preferably provided so as to be distributed more than the other partial areas with respect to the partial area overlapping the piezoelectric element 5 when the vibrating body 3a is viewed in plan. .

  4B, the voids V are distributed more than the other partial areas with respect to the partial areas along the contour of the piezoelectric element 5 when the vibrating body 3a is viewed in plan. It may be provided.

  4C, the voids V may be provided so as to be distributed along the boundary between the frame body 2 and the vibrating body 3a in plan view. In this case, since the void V suppresses the propagation of the vibration around the frame 2 that becomes a vibration node, it is possible to cause a deviation between the incident speed of the vibration from the piezoelectric element 5 and the reflection speed.

  Thereby, the peak P of the sound pressure at the resonance point can be dispersed on the surface and inside of the vibrating body 3a and the frequency characteristic of the sound pressure can be flattened, so that a favorable frequency characteristic can be obtained.

  In FIG. 4C, the hatched area in which the voids V are more distributed is shown inside the frame body 2, but the voids V are formed on the frame portion of the frame body 2 (that is, the peripheral portion of the diaphragm 3 to be sandwiched). It doesn't matter if you get in. In such a case, the void V also plays a role of securely biting an adhesive or the like and bonding the frame body 2 and the diaphragm 3 more firmly.

  Next, a distribution example of the void V in the thickness direction of the vibrating body 3a will be described with reference to FIGS. 5A to 5C. 5A to 5C are schematic cross-sectional views (No. 1) to (No. 3) showing examples of the distribution of voids V. FIG.

  As shown in FIG. 5A, the void V is preferably provided close to the main surface on the side where the piezoelectric element 5 is attached in the thickness direction of the vibrating body 3a. As a result, it is possible to vary the sound pressure peak P at the resonance point between the main surface on which the piezoelectric element 5 is attached and the main surface on the opposite side, and to flatten the frequency characteristics of the sound pressure. Good sound pressure frequency characteristics can be obtained.

  In addition, this point does not prevent providing the void V in multiple stages in the thickness direction of the vibrating body 3a as shown in FIG. 5B. As shown in FIG. 5B, when the voids V are provided in multiple stages, it is possible to vary the sound pressure peak P at the resonance point in the entire thickness direction of the vibrating body 3a and flatten the frequency characteristics of the sound pressure. Therefore, it is possible to obtain a good frequency characteristic of sound pressure.

  Further, when the void V is provided as an open pore as already shown in FIG. 3D and the like, the void V is different from the main surface on the side where the piezoelectric element 5 is attached to the vibrating body 3a as shown in FIG. 5C. It is preferable to be provided on the opposite main surface.

  Thereby, since the void V is not embedded by the resin layer 7, the propagation distance of the sound on the surface of the vibrating body 3a can be reliably made different from the propagation distance inside. Therefore, the resonance of the vibrating body 3a can be smoothed and the frequency characteristic of the sound pressure can be flattened, so that it is possible to obtain a good frequency characteristic of the sound pressure.

  Even if the void V as an open hole is provided on the main surface on the side where the piezoelectric element 5 is attached, and the void V is embedded in the resin layer 7, the vibrating body 3a, the piezoelectric element 5 and the resin layer Needless to say, a certain effect can be obtained in varying the sound pressure peak P at the resonance point of the entire composite vibrator integrated in step 7.

  Next, a sound generation device and an electronic apparatus equipped with the sound generator 1 according to the embodiment described so far will be described with reference to FIGS. 6A and 6B. FIG. 6A is a diagram illustrating a configuration of the sound generation device 20 according to the embodiment, and FIG. 6B is a diagram illustrating a configuration of the electronic device 50 according to the embodiment. In addition, in both figures, only the component required for description is shown and description about a general component is abbreviate | omitted.

  The sound generation device 20 is a sound generation device such as a so-called speaker, and includes, for example, a sound generator 1 and a housing 30 that houses the sound generator 1 as shown in FIG. 6A. The housing 30 resonates the sound generated by the sound generator 1 and radiates the sound to the outside through an opening (not shown) formed in the housing 30. By having such a housing 30, for example, the sound pressure in a low frequency band can be increased.

  The sound generator 1 can be mounted on various electronic devices 50. For example, in FIG. 6B shown below, it is assumed that the electronic device 50 is a mobile terminal device such as a mobile phone or a tablet terminal.

  As shown in FIG. 6B, the electronic device 50 includes an electronic circuit 60. The electronic circuit 60 includes, for example, a controller 50a, a transmission / reception unit 50b, a key input unit 50c, and a microphone input unit 50d. The electronic circuit 60 is connected to the sound generator 1 and has a function of outputting an audio signal to the sound generator 1. The sound generator 1 generates sound based on the sound signal input from the electronic circuit 60.

  The electronic device 50 includes a display unit 50e, an antenna 50f, and the sound generator 1. Further, the electronic device 50 includes a housing 40 that accommodates these devices.

  6B shows a state in which each device including the controller 50a is accommodated in one housing 40, but the accommodation form of each device is not limited. In the present embodiment, it is sufficient that at least the electronic circuit 60 and the sound generator 1 are accommodated in one housing 40.

  The controller 50 a is a control unit of the electronic device 50. The transmission / reception unit 50b transmits / receives data via the antenna 50f based on the control of the controller 50a.

  The key input unit 50c is an input device of the electronic device 50 and accepts a key input operation by an operator. The microphone input unit 50d is also an input device of the electronic device 50, and accepts a voice input operation by an operator.

  The display unit 50e is a display output device of the electronic device 50, and outputs display information based on the control of the controller 50a.

  The sound generator 1 operates as a sound output device in the electronic device 50. The sound generator 1 is connected to the controller 50a of the electronic circuit 60, and emits sound upon application of a voltage controlled by the controller 50a.

  In FIG. 6B, the electronic device 50 is described as a portable terminal device. However, the electronic device 50 is not limited to the type of the electronic device 50, and may be applied to various consumer devices having a function of emitting sound. . For example, flat-screen TVs and car audio devices can of course be used for products having a function of emitting sound such as "speak", for example, various products such as vacuum cleaners, washing machines, refrigerators, microwave ovens, etc. .

  As described above, the sound generator according to the embodiment includes an exciter (piezoelectric element) and a substantially flat vibrating body. The exciter vibrates when an electric signal is input thereto. The vibrator is provided with the exciter, and vibrates with the exciter by the vibration of the exciter. The vibrating body is provided with a void.

  Therefore, according to the sound generator according to the embodiment, it is possible to obtain a favorable frequency characteristic of sound pressure.

  In the above-described embodiment, the case where the piezoelectric element is provided on one main surface of the vibrating body is mainly described as an example. However, the present invention is not limited to this, and the piezoelectric element is provided on both surfaces of the vibrating body. It may be provided.

  Further, in the above-described embodiment, the case where the shape of the inner region of the frame is a substantially rectangular shape is taken as an example, and it may be a polygon, but is not limited thereto, and is not limited to a circle or an ellipse. It may be a shape.

  In the above-described embodiment, the case where the resin layer is formed so as to cover the piezoelectric element and the vibrating body in the frame of the frame has been described as an example. However, such a resin layer is not necessarily formed.

  Further, in the above-described embodiment, the case where the diaphragm is configured by a thin film such as a resin film has been described as an example. However, the present invention is not limited thereto, and may be configured by a plate-like member, for example.

  In the above-described embodiment, the case where the support body that supports the vibrating body is a frame body and the periphery of the vibrating body is supported is described as an example. However, the present invention is not limited to this. For example, it is good also as supporting only the both ends of the longitudinal direction or a transversal direction of a vibrating body.

  In the above-described embodiment, the case where the exciter is a piezoelectric element has been described as an example. However, the exciter is not limited to the piezoelectric element, and has a function of vibrating when an electric signal is input. What is necessary is just to have.

  For example, an electrodynamic exciter, an electrostatic exciter, or an electromagnetic exciter well known as an exciter for vibrating a speaker may be used.

  The electrodynamic exciter is such that an electric current is passed through a coil disposed between the magnetic poles of a permanent magnet to vibrate the coil. The electrostatic exciter is composed of two metals facing each other. A bias and an electric signal are passed through the plate to vibrate the metal plate, and an electromagnetic exciter is an electric signal that is passed through the coil to vibrate a thin iron plate.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1, 1 'Sound generator 2 Frame body 3 Diaphragm 3a Vibration body 3b Intermediate | middle layer 5 Piezoelectric element 5a, 5b, 5c, 5d Piezoelectric layer 5e Internal electrode layer 5f, 5g Surface electrode layer 5h, 5j External electrode 6a, 6b Lead terminal 7 Resin layer 20 Sound generator 30, 40 Housing 50 Electronic device 50a Controller 50b Transmitter / receiver unit 50c Key input unit 50d Microphone input unit 50e Display unit 50f Antenna 60 Electronic circuit 70 Nozzle P Peak V Void

Claims (12)

An exciter that vibrates upon receipt of an electrical signal;
The exciter is attached, and a substantially flat vibrating body that vibrates with the exciter due to vibration of the exciter ;
A support for supporting the vibrating body ,
The sound generator is characterized in that pores are provided in the vibrating body so as to be distributed along a boundary between the support body and the vibrating body when seen in a plan view . The pores are
The sound generator according to claim 1, wherein the sound generator is also provided in the vicinity of the exciter. The pores are
The acoustic generator according to claim 2, wherein when the vibrator is viewed in plan, the acoustic generator is provided so as to be distributed more than the other partial areas with respect to the partial area overlapping with the exciter. The pores are
The acoustic generator according to claim 2 , wherein when the vibrating body is viewed in plan, the acoustic wave generator is provided so as to be distributed more in the partial area along the contour of the exciter than in other partial areas. . The pores are
Sound generator according to any one of claims 1-4, characterized in that it is provided so as to be distributed substantially in parallel with the plane direction of the vibrating body. The vibrator is
A laminate formed by sandwiching an intermediate layer,
The pores are
The acoustic generator according to claim 5 , wherein the acoustic generator is provided as a closed pore formed inside the vibrating body by being formed in the intermediate layer. The pores are
Sound generator according to claim 5 or 6, characterized in that provided as open pores the opened in the surface of the vibrating body. The pores are
At least a part of the inner wall of the gas holes, sound generator according to any one of claims 1-7, characterized in that provided so as to be covered by the compositions of the vibrator different compositions. The vibrating body, an acoustic generator according to any one of claims 1-8, characterized in that it consists of a resin film. The sound generator according to any one of claims 1 to 9 , wherein the exciter is a bimorph type stacked piezoelectric element. The sound generator according to any one of claims 1 to 10 ,
A sound generation device comprising: a housing that houses the sound generator. The sound generator according to any one of claims 1 to 10 ,
An electronic circuit connected to the acoustic generator;
A housing for housing the electronic circuit and the acoustic generator;
An electronic device having a function of generating sound from the sound generator.

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