JP2016184786A - Acoustic generation device and electronic apparatus including the same - Google Patents

Abstract

A sound generator and an electronic device using the same are provided in which deterioration of sound due to unnecessary vibration of a frame is reduced.
SOLUTION: A casing 21 having a panel 21a positioned on the first direction side and a panel 21b positioned on the second direction side opposite to the first direction, and a peripheral edge of a through hole 24 provided in the panel 21a. It is disposed between the provided frame 5, the vibrating body 3 having a peripheral edge joined to the frame 5, the exciter provided in the vibrating body 3, and the frame 5 and the panel 21 b. It has a plurality of support columns 41a and 41b in which the end on the one direction side is joined to the frame 5 and the end on the second direction side is joined to the panel 21b.
[Selection] Figure 2

Description

  The present invention relates to a sound generator and an electronic apparatus using the same.

  2. Description of the Related Art Conventionally, an acoustic generator is known in which a sound generator that generates sound by vibrating a film stretched inside a frame with a piezoelectric element is attached to a through-hole formed in a panel of a casing (for example, , See Patent Document 1).

JP 2002-112389 A

  In the sound generator described above, it is desirable that the film vibrates so that a portion joined to the frame body becomes a fixed end in order to generate good sound. However, the above-described conventional sound generator has a problem that the generated sound is deteriorated due to unnecessary vibration generated in the frame.

  The present invention has been devised in view of such problems in the prior art, and an object of the present invention is to provide a sound generator in which deterioration of sound due to unnecessary vibration of the frame body is reduced, and an electronic device using the same. To provide equipment.

  The sound generator according to the present invention is provided on the first panel, a housing having a first panel located on the first direction side and a second panel located on the second direction side opposite to the first direction. A frame provided at the periphery of the formed through-hole, a vibrating body having a peripheral edge joined to the frame, an exciter provided in the vibrating body, and the frame and the second panel And a plurality of support columns, each having an end on the first direction side joined to the frame body, and an end on the second direction side joined to the second panel.

  The electronic device of the present invention includes the sound generator and an electronic circuit connected to the sound generator.

  According to the sound generator of the present invention, it is possible to obtain a sound generator in which deterioration of sound due to unnecessary vibration of the frame body is reduced. According to the electronic device of the present invention, it is possible to obtain an electronic device capable of generating good sound.

It is a perspective view showing typically the sound generator of a 1st embodiment of the present invention. It is the sectional view on the AB line of FIG. It is the CD sectional view taken on the line of FIG. It is a top view showing typically the sound generator of a 1st embodiment of the present invention. It is a top view which shows typically the sound generator of 2nd Embodiment of this invention. It is a block diagram which shows the structure of the electronic device of 3rd Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a sound generator and an electronic apparatus using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, directions are represented by orthogonal coordinates composed of an x-axis, a y-axis and a z-axis that are orthogonal to each other.

(First embodiment)
FIG. 1 is a perspective view schematically showing a sound generator according to a first embodiment of the present invention. 2 is a cross-sectional view taken along the line AB of FIG. 3 is a cross-sectional view taken along line CD in FIG. FIG. 4 is a plan view schematically showing the sound generator according to the first embodiment of the present invention. FIG. 4 shows a state seen from the −z direction, and shows a state seen through the panel 21b. As shown in FIGS. 1 to 4, the sound generator of the present embodiment includes an exciter 1, a vibrating body 3, a frame body 5, a resin layer 20, a housing 21, and a plurality of support columns (supports 41 a , Strut 41b, strut 41c, strut 41d).

  The frame 5 is configured by a frame 5a and a frame 5b having the same shape. Each of the frame body 5a and the frame body 5b has a rectangular frame shape, and has a thickness of about 0.1 mm to 10 mm, for example. The frame body 5a and the frame body 5b have a shape that is long in the x-axis direction. The frame body 5a and the frame body 5b can be formed using various materials, but desirably have high rigidity. For example, the frame body 5a and the frame body 5b can be formed using a resin such as a hard resin, a plastic, and an engineering plastic, a metal such as ceramics and stainless steel, and various ceramics. The shapes of the frame body 5a and the frame body 5b are not limited to rectangles, and may be hexagonal shapes or elliptical shapes, for example.

  The vibrating body 3 has a flat shape, and specifically has a film shape (film shape). The vibrating body 3 has a rectangular planar shape that is long in the x-axis direction. The vibrating body 3 can be formed using various materials. For example, the vibrating body 3 is made of a resin such as polyethylene, polyimide, polypropylene, or polystyrene, paper made of pulp or fiber, thin metal, or the like. Can be formed. The thickness of the vibrating body 3 is, for example, 10 to 200 μm. Moreover, the vibrating body 3 should just have a flat shape, for example, may be plate shape.

  Then, the vibrating body 3 is sandwiched between the frame body 5a and the frame body 5b and joined by an adhesive in a state where tension is applied. The frame body 5a and the frame body 5b It is supported so that it can vibrate. For example, when the frame 5b is not provided, for example, the vibrating body 3 may be bonded to the surface of the frame 5a in the + z direction, and the vibrating body 3 may be bonded to the inner side surface of the frame 5a. May be.

  The exciter 1 is a piezoelectric element having a rectangular plate shape. The entire surface of the exciter 1 on the + z direction side is joined to the surface of the vibrating body 3 on the −z direction side. Although not shown in detail, the exciter 1 includes a laminated body in which piezoelectric layers made of piezoelectric ceramics and internal electrode layers are alternately laminated, and a surface electrode formed on the surface of the laminated body. Has been. The internal electrode layers are alternately drawn to both end faces in the longitudinal direction (x-axis direction) of the multilayer body, and are connected to the surface electrodes, respectively. Further, the main surface of the exciter 1 on the vibrating body 3 side and the vibrating body 3 are bonded by, for example, an adhesive or a double-sided tape.

Piezoelectric layers of the exciter 1 include piezoelectric materials conventionally used such as lead-free piezoelectric materials such as lead zirconate (PZ), lead zirconate titanate (PZT), Bi layered compounds, and tungsten bronze structure compounds. Ceramics can be used. The internal electrode layer of the exciter 1 can be formed using various known metal materials. For example, a material containing a metal component composed of silver and palladium and a material component constituting the piezoelectric layer can be used. The surface electrode of the exciter 1 can be formed using various known metal materials. For example, a material containing a metal component made of silver and a glass component can be used.

  The exciter 1 is a bimorph type piezoelectric element, and when an electric signal is input to the surface electrode via a wiring (not shown), at any moment, one side in the thickness direction (z-axis direction) Expansion and contraction is reversed on the other side. Therefore, when the electric signal is input, the exciter 1 bends and vibrates in the z-axis direction, thereby causing the vibrating body 3 to bend and vibrate. Then, sound is generated when the vibrating body 3 vibrates. As the exciter 1, for example, a monomorph type vibration element configured by bonding a piezoelectric element that receives an electric signal to expand and contract and vibrates and a metal plate may be used.

  The resin layer 20 is filled over the entire inside of the frame 5a so as to embed the exciter 1 therein. The resin layer 20 can be formed using various known materials. For example, a resin such as an acrylic resin or a silicon resin, rubber, or the like can be used. In addition, the thickness of the resin layer 20 is desirably a thickness that completely covers the exciter 1. The resin layer 20 vibrates together with the vibrating body 3, and sound is also generated from the surface of the resin layer 20 on the −z direction side. The resin layer 20 is not essential and may be omitted depending on circumstances.

  The casing 21 has a rectangular parallelepiped box shape, and is configured by joining a panel 21a, a panel 21b, a panel 21c, a panel 21d, a panel 21e, a panel 21f, and a panel 21g. Each panel (21a-21g) has a rectangular plate shape.

  The panel 21a arranged on the + z direction side and the panel 21b arranged on the −z direction side are arranged so as to face each other with an interval in the z-axis direction. The ends in the + x direction of the panels 21a and 21b are generally connected by the panel 21c, and the ends in the −x direction of the panels 21a and 21b are generally connected by the panel 21d. The ends in the + y direction of the panel 21a and the panel 21b are entirely connected by the panel 21f.

  The ends in the −y direction of the panel 21a and the panel 21b are connected by the panel 21e except for the end in the + x direction. A panel 21g extending in the + y direction is disposed at the end of the panel 21e in the + x direction, and a gap is formed between the panel 21g and the panel 21c. A duct 23 is formed by a space surrounded by the panel 21g, the panel 21c, the panel 21a, and the panel 21b, and the internal space 22 of the housing 21 and the external space are connected via the duct 23. Thereby, the sound generated on the surface on the −z direction side of the resin layer 20 can be resonated in the internal space 22 and radiated from the duct 23 to the external space.

  Note that the outer shape of the housing 21 is not limited to a rectangular parallelepiped shape, and may be, for example, a regular dodecahedron, a triangular prism shape, or a cylindrical shape. The casing 21 desirably has a certain degree of rigidity, and can be formed using a known material such as wood, synthetic resin, or metal.

  A rectangular through hole 24 is formed in the panel 21a, and the surface on the + z direction side of the frame 5b is joined to the periphery of the through hole 24 on the surface on the −z direction side of the panel 21a. In this way, the through hole 24 is closed by the vibrating body 3, and the main surface in the + z direction of the vibrating body 3 is exposed to the external space through the through hole 24.

The four struts (41a to 41d) each have a columnar shape that is long in the z-axis direction, and are disposed with a space between each other between the frame 5a and the panel 21b. Specifically, one of the four support columns (41a to 41d) is disposed at each of the four corners of the rectangular frame 5a. Each of the columns (41a to 41d) has an end on the + z direction side joined to the frame 5a, and an end on the −z direction side joined to the panel 21b.

  In addition, the external shape of support | pillar (41a-41d) is not limited to a column shape, For example, you may be prismatic shape or elliptical column shape. Moreover, the center part of the support | pillar may be dented and it does not matter even if it swells. The struts (41a to 41d) desirably have high rigidity, and can be formed using a known material such as wood, synthetic resin, or metal. The diameter of each of the columns (41a to 41d) is preferably equal to or smaller than the width of the frame body 5, and is set to, for example, about 1 mm to 10 mm. In addition, it is desirable that the length of each of the columns (41a to 41d) is the same as or slightly longer than the interval between the frame 5a and the panel 21b. Thereby, since the frame 5 can be pressed with the panel 21a and the support | pillar (41a-41d), the vibration of the frame 5 can be reduced effectively.

  As described above, the sound generation device of the present embodiment includes the casing 21, the frame 5, the vibrating body 3, the exciter 1, and the plurality of support columns (41a to 41d). The housing | casing 21 has the panel 21a and the panel 21b. The panel 21a is located on the first direction (+ z direction) side, and the panel 21b is located on the second direction (−z direction) side opposite to the first direction (+ z direction). The frame 5 is provided at the periphery of the through hole 24 provided in the panel 21a. The periphery of the vibrating body 3 is joined to the frame 5. The exciter 1 is provided on the vibrating body 3. The plurality of support columns (41a to 41d) are arranged between the frame body 5 and the panel 21b, and the end on the first direction (+ z direction) side is joined to the frame body 5, and the second direction (−z direction). ) Side end is joined to the panel 21b. Since the sound generator of the present embodiment having such a configuration can suppress the vibration of the frame body 5, it is possible to reduce the deterioration of the sound due to the vibration of the frame body 5.

  When the column (41a to 41d) is not provided, if the rigidity of the casing 21 is insufficient, the fixing of the frame 5 becomes incomplete, and the frame 5 is vibrated. If the fixing of the frame 5 is incomplete, the portion joined to the frame 5 of the vibrating body 3 is no longer the fixed end, so that the vibration is disturbed and attenuated, and the generated sound deteriorates (sound quality and sound pressure). Decreases). The sound generator of this embodiment can reduce the vibration of the frame 5 by the support columns (41a to 41d), and can reduce the deterioration of the sound caused by the vibration of the frame 5.

  Moreover, in the sound generator of this embodiment, the frame 5 is pinched | interposed with the panel 21a and the some support | pillar (41a-41d). Thereby, since the vibration of the frame 5 in the z-axis direction can be effectively reduced, it is possible to further reduce the deterioration of sound caused by the vibration of the frame 5.

  Further, in the sound generation device of the present embodiment, the plurality of support columns (41 a to 41 d) are arranged along the frame body 5 at intervals. Thereby, the deterioration of the sound by the sound generated on the surface on the −z direction side of the resin layer 20 resonating in the space surrounded by the support can be reduced.

  Moreover, in the sound generator of this embodiment, the frame 5 is a rectangular shape, and support | pillars (41a-41d) are provided in the four corners of the frame 5, respectively. Thereby, the vibration of the frame 5 can be effectively suppressed with a small number of pillars, so that the deterioration of the sound due to the vibration of the frame 5 and the sound generated on the surface of the resin layer 20 on the −z direction side are the pillars. It is possible to prevent both deterioration of sound due to resonance in the enclosed space.

  The sound generator of this embodiment can be manufactured as follows, for example. First, a binder, a dispersant, a plasticizer, and a solvent are added to the powder of the piezoelectric material and stirred to prepare a slurry. As the piezoelectric material, any of lead-based and non-lead-based materials can be used. Next, the obtained slurry is formed into a sheet shape to produce a green sheet. A conductor paste is printed on the green sheet to form a conductor pattern to be an internal electrode, and the green sheet on which the conductor pattern is formed is laminated to produce a laminated molded body.

  Next, this laminated molded body is degreased, fired, and cut into a predetermined size to obtain a laminated body. If necessary, the outer periphery of the laminate is processed. Next, a conductor pattern that becomes a surface electrode layer is formed by printing a conductor paste on the surface of the laminate. And the structure used as the exciter 1 can be obtained by baking an electrode at predetermined temperature. Thereafter, in order to impart piezoelectricity to the exciter 1, a DC voltage is applied to the surface electrode to polarize the piezoelectric layer of the exciter 1. In this way, the exciter 1 can be obtained.

  Next, the peripheral part of the vibrating body 3 in a tensioned state is sandwiched between the frame body 5a and the frame body 5b and joined with an adhesive, and the exciter 1 is joined to the vibrating body 3 with an adhesive. And after joining the frame 5b to the peripheral part of the through-hole 24 of the panel 21a with an adhesive agent, the support | pillar (41a-41d) and the panel (21a-21g) are joined with an adhesive agent, and the housing | casing 21 is formed. Thus, the sound generator of this embodiment can be obtained.

(Second Embodiment)
FIG. 5 is a plan view schematically showing a sound generator according to the second embodiment of the present invention. FIG. 5 shows a state seen from the −z direction, and shows a state seen through the panel 21b. Moreover, in this embodiment, a different point from the sound generator of 1st Embodiment mentioned above is demonstrated, the same referential mark is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  As shown in FIG. 5, the sound generator according to the present embodiment includes a column 41 e and a column 41 f in addition to the four columns (41 a to 41 d). The rest is the same as the sound generator of the first embodiment described above. The support column 41e is disposed so as to be positioned at one central portion of the two long sides of the rectangular frame 5, and the support column 41f is positioned at the other central portion of the two long sides of the frame 5. Are arranged as follows. The pillar 41e and the pillar 41f are the same in material and shape as the four pillars (41a to 41d), the + z direction end is joined to the frame 5a, and the −z direction end is attached to the panel 21b. It is joined.

  Since the sound generator of the present embodiment includes the support column 41e and the support column 41f, the vibration of the frame body 5 can be further suppressed, so that the deterioration of the sound caused by the vibration of the frame body 5 can be further reduced. it can.

  Further, in addition to the central portion of the two long sides of the frame body 5, the support column may be arranged at the central portion of the two short sides of the frame body 5. In other words, in addition to the four corners of the frame body 5, pillars may be provided at the centers of the four sides of the frame body 5. Thereby, since the vibration of the frame 5 can be further suppressed, the deterioration of the sound caused by the vibration of the frame 5 can be further reduced. If the number of support columns is further increased, the vibration of the frame 5 can be further suppressed. However, since the resonance of the acoustic internal space 22 generated on the surface of the resin layer 20 on the −z direction side becomes large, In this respect, it is not preferable to increase the number of support columns.

(Third embodiment)
FIG. 6 is a block diagram showing a configuration of an electronic apparatus according to the third embodiment of the present invention. As shown in FIG. 6, the electronic apparatus of the present embodiment includes a sound generator 29, an electronic circuit 60, a key input unit 50c, a microphone input unit 50d, a display unit 50e, and an antenna 50f. Yes. FIG. 6 is a block diagram assuming an electronic device such as a mobile phone, a tablet terminal, or a personal computer.

  The electronic circuit 60 includes a control circuit 50a and a communication circuit 50b. The electronic circuit 60 is connected to the sound generator 29 and has a function of outputting a sound signal to the sound generator 29. The control circuit 50a is a control unit of the electronic device. The communication circuit 50b transmits and receives data through the antenna 50f based on the control of the control circuit 50a.

  The key input unit 50c is an input device of an electronic device and accepts a key input operation by an operator. The microphone input unit 50d is also an input device of an electronic device, and accepts an audio input operation by an operator. The display unit 50e is a display output device of an electronic device, and outputs display information based on the control of the control circuit 50a.

  The sound generator 29 is the sound generator of the first embodiment described above. The sound generation device 29 functions as a sound output device in the electronic device, and generates sound (including sound outside the audible frequency band) based on the sound signal input from the electronic circuit 60. The sound generator 29 is connected to the control circuit 50a of the electronic circuit 60, and generates a sound upon application of a voltage controlled by the control circuit 50a.

  As described above, the electronic apparatus according to this embodiment includes the sound generation device 29 and the electronic circuit 60 connected to the sound generation device 29. Since the electronic apparatus of this embodiment generates sound using the sound generator 29 of the first embodiment described above, it can generate sound with good sound quality.

  As an example of the structure of the electronic device, for example, the electronic circuit 60, the key input unit 50c, the microphone input unit 50d, the display unit 50e, the antenna 50f, and the acoustic generator 29 shown in FIG. Can be. In addition, as another example of the structure of the electronic device, a device main body including an electronic circuit 60, a key input unit 50c, a microphone input unit 50d, a display unit 50e, and an antenna 50f shown in FIG. 29 may be connected via an electrical lead or the like so that an electrical signal can be transmitted.

  Further, the electronic device of the present embodiment does not have to include all of the key input unit 50c, the microphone input unit 50d, the display unit 50e, and the antenna 50f shown in FIG. 6, and the sound generator 29 and the electronic circuit 60 at least. In addition, the electronic device may have other components. Furthermore, the electronic circuit 60 is not limited to the electronic circuit 60 having the above-described configuration, and may be an electronic circuit having another configuration.

  Further, the electronic device of the present embodiment is not limited to the above-described electronic devices such as a mobile phone, a tablet terminal, and a personal computer. In various electronic devices such as televisions, audio devices, radios, vacuum cleaners, washing machines, refrigerators, and microwave ovens having a function of generating sound and sound, the sound generator 29 of the first embodiment described above is used for sound generation. It can be used as a device. In addition, it may replace with the sound generator of 1st Embodiment, and may use the sound generator of another form which has the same performance.

(Modification)
The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, an example in which one exciter 1 is attached to the surface of the vibrating body 3 is shown, but the present invention is not limited to this. For example, a larger number of exciters 1 may be mounted on the vibrating body 3. Further, for example, the exciter 1 and the resin layer 20 may be provided on both surfaces of the vibrating body 3.

  In the above-described embodiment, an example in which a piezoelectric element is used as the exciter 1 is shown, but the present invention is not limited to this. The exciter 1 only needs to have a function of converting an electric signal into mechanical vibration, and another apparatus having a function of converting an electric signal into mechanical vibration may be used as the exciter 1. For example, an electrodynamic exciter, an electrostatic exciter, or an electromagnetic exciter well known as an exciter for vibrating a speaker may be used as the exciter 1. 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.

1: Exciter 3: Vibrators 5, 5a, 5b: Frame 21: Housing 24: Through-hole 29: Sound generators 41a, 41b, 41c, 41d, 41e, 41f: Prop 60: Electronic circuit

Claims (6)

A housing having a first panel located on the first direction side and a second panel located on the second direction side opposite to the first direction;
A frame provided at the periphery of the through hole provided in the first panel;
A vibrating body having a peripheral edge joined to the frame;
An exciter provided in the vibrator;
A plurality of frames disposed between the frame and the second panel, wherein the end on the first direction side is joined to the frame, and the end on the second direction side is joined to the second panel And
The sound generator characterized by having.   The sound generator according to claim 1, wherein the frame is sandwiched between the first panel and the plurality of support columns.   The sound generating device according to claim 1, wherein the plurality of support columns are arranged at intervals along the frame body.   The sound generator according to any one of claims 1 to 3, wherein the frame has a rectangular shape, and the pillars are respectively provided at four corners of the frame.   The sound generating device according to claim 4, wherein the support columns are respectively provided at the centers of the four sides of the frame.   6. An electronic apparatus comprising: the sound generator according to claim 1; and an electronic circuit connected to the sound generator.

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