JP2014127843A - Acoustic generator, acoustic generating device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain good sound pressure frequency characteristics.SOLUTION: An acoustic generator includes: an exciter 5 which vibrates when an electric signal is input thereto; a vibrating body 3a to which the exciter 5 is attached, the vibrating body 3a which is vibrated with the exciter 5 by vibrations of the exciter 5; and a frame body 2 which is provided at an outer peripheral part of the vibrating body 3a and supports the vibrating body 3a in a substantially flat manner. The frame body 2 has holes H1. A substrate 2a having holes 2aa corresponding to the holes H1 is fixed to a main surface of the frame body 2 by pins 8 or screws 9 which are inserted into the holes 2aa and the holes H1.

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.

  The sound generator according to one aspect of the embodiment includes an exciter, a vibrating body, and a frame. The exciter vibrates upon receiving an electrical signal. The vibrator is attached with the exciter, and vibrates together with the exciter by vibration of the exciter. The frame body is provided on an outer peripheral portion of the vibrating body and supports the vibrating body substantially flat. Moreover, the said frame has a hole part, and the board | substrate which has a hole corresponding to this hole part is being fixed to the main surface with the pin or screw inserted in the said hole and the said hole part.

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

It is a typical top view showing a schematic structure of a basic sound generator. It is an AA line sectional view (the 1) of an acoustic generator shown in Drawing 1A. It is an AA line sectional view of the sound generator shown in Drawing 1A (the 2). It is a figure which shows an example of the frequency characteristic of a sound pressure. It is the sound generator which concerns on embodiment, Comprising: (a) is typical top view (the 1) which shows an example of a structure, (b) is the frame of a sound generator shown in (a), a board | substrate, and The typical perspective view which shows a pin, (c) And (d) is a typical perspective view which shows the other example of a pin. It is a BB line sectional view at the time of fixing a substrate to a sound generator shown in Drawing 3A (a) with a screw, and (a) is a mimetic diagram showing a state before fixing a substrate to a frame with a screw. FIG. 9B is a schematic cross-sectional view showing a state after the substrate is fixed to the frame with screws. It is the acoustic generator which concerns on embodiment, Comprising: (a) is typical top view (the 2) which shows an example of a structure, (b) is the frame, board | substrate, and board | substrate of the acoustic generator shown to (a) It is a typical perspective view which shows a screw. FIG. 3C is a cross-sectional view taken along the line C-C in the case where the substrate is fixed to the sound generator shown in FIG. 3C (a) with a screw, and FIG. FIG. 9B is a schematic cross-sectional view showing a state after the substrate is fixed to the frame with screws. (a) And (b) is a modification of a screw, and is a typical sectional view showing a state after fixing a substrate with a screw, and (c) is a typical showing an other modification of a screw. It is a perspective view. (A), (b) and (c) are typical top views showing incision of the head of a screw. It is a figure which shows the structure of the sound generator which concerns on embodiment. It is a figure which shows the structure of the electronic device which concerns on embodiment. It is a typical top view showing an example of the composition of the sound generator concerning an embodiment. (Part 1) It is a typical top view showing an example of the composition of the sound generator concerning an embodiment. (Part 2) It is a typical top view showing an example of the composition of the sound generator concerning an embodiment. (Part 3) It is a typical top view showing an example of the composition of the sound generator concerning an embodiment. (Part 4)

  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 1B will be described with reference to FIGS. 1A to 1C. 1A is a schematic plan view showing a schematic configuration of an acoustic generator 1B, FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. 1A, and FIG. 1C is a cross-sectional view of FIG. It is -A 'sectional view taken on the line (the 2).

  For easy understanding, FIGS. 1A to 1C illustrate a three-dimensional orthogonal coordinate system including a Z-axis in which a vertical upward direction is a positive direction and a vertical downward direction is a negative direction. Such an orthogonal coordinate system may also be shown in other drawings used in the following description.

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

  As shown in FIG. 1A, the sound generator 1B includes a frame 2, a diaphragm 3, a piezoelectric element 5, and lead wires 6a and 6b. 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.

Further, as illustrated in FIG. 1B as an example, the frame body 2 functions as a support body that supports the diaphragm 3 at the periphery of the diaphragm 3. The diaphragm 3 has a plate-like shape or a film-like shape, and its peripheral portion is fixed to the frame body 2 and is supported substantially flat in a state where tension is uniformly applied within the frame of the frame body 2. The

  In the example shown in FIG. 1C, the frame body 2 is configured by two frame members having a rectangular frame shape and the same shape, and supports the diaphragm 3 by sandwiching the peripheral edge portion of the diaphragm 3. Functions as a body. 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

  In this case, since the tension of the diaphragm 3 can be stabilized by sandwiching the diaphragm 3 between the two frame members, the frequency characteristics of the sound generator 1 'are durable and do not fluctuate for a long time. Even better because you can.

  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.

  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, and regular n-gon, or an oval shape. There may be. In the present embodiment, as shown in FIG.

  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 or FIG. 1C, the piezoelectric element 5 includes, for example, a laminate in which piezoelectric layers 5a, 5b, 5c, and 5d made of ceramics and three internal electrode layers 5e are alternately laminated. Body, 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 wires 6a and 6b are connected to the external electrodes 5h and 5j. The lead wires 6a and 6b are conducting wires for inputting an electric signal from the outside.

  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 or 1C. 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 wires 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 wires 6a and 6b can be formed using various metal materials. For example, when the lead wires 6a and 6b are configured using flexible wiring in which a metal foil such as copper or aluminum is sandwiched between resin films, the piezoelectric element 5 can be reduced in height.

  Moreover, as shown in FIG. 1B or FIG. 1C, the sound generator 1B is arranged so as to cover the surfaces of the piezoelectric element 5 and the vibrating body 3a in the frame of the frame 2, and the vibrating body 3a and the piezoelectric element 5 An integrated 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 damper effect can be induced by embedding the piezoelectric element 5 in the resin layer 7, the resonance phenomenon can be suppressed, and the peak or dip in the frequency characteristic of the sound pressure can be suppressed to be small.

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

  As described above, the vibrating body 3a, the piezoelectric element 5, and the resin layer 7 are integrated to form a composite vibrating body that vibrates integrally.

  In FIG. 1B or 1C, the bimorph multilayer piezoelectric element is taken as an example of the piezoelectric element 5. However, the piezoelectric element 5 is not limited to this. For example, the expanding and contracting piezoelectric element 5 is attached to the vibrating body 3a. It may be a unimorph type.

  By the way, as shown in FIGS. 1A to 1C, 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. 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.

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.

  Here, focus on the frame 2. As described above, the frame body 2 is a support body that supports the vibrating body 3a while applying a uniform tension. However, when the vibrating body 3a vibrates, the frame body 2a is also induced by resonance of the vibrating body 3a. The body 2 itself is also vibrating. The frame 2 returns a reflected wave to the vibrating body 3a. Therefore, the frame body 2 can be regarded as one of the components of the above-described composite vibration body that vibrates integrally.

  Therefore, in the present embodiment, by providing the substrate 2a fixed with pins or screws to the frame body 2, the vibration wave is disturbed around the substrate 2a, so that the frame body 2 returns to the vibration body 3a. The reflected wave was disturbed. Thus, the resonance frequency is made partially ununiform so that the resonance mode degeneracy is solved and dispersed, and the height of the peak P is lowered and the peak width is widened.

  Hereinafter, the sound generators 1 and 1A according to the embodiment will be sequentially described specifically using FIGS. 3A to 7D. First, FIG. 3A (a) is a schematic plan view (part 1) showing an example of the configuration of the acoustic generator 1 according to the embodiment. FIG. 3C (a) is a schematic plan view (part 2) showing an example of the configuration of the acoustic generator 1A according to the embodiment.

  In addition, in each drawing shown below including the schematic plan view of FIG. 3A and FIG. 3B, illustration of the resin layer 7 may be abbreviate | omitted similarly to FIG. 1A for convenience of explanation. In each drawing, only one of the two frame members constituting the frame 2 is shown. Moreover, in FIG. 3A and FIG. 3C, the centerline CL1 of the frame 2 is shown.

  First, an example of the configuration of the sound generator 1 according to the embodiment shown in FIG. 3A will be described.

  As shown in FIG. 3A, the sound generator 1 includes a substrate 2a in a frame 2 in addition to the sound generator 1B shown in FIGS. 1A to 1C. As shown in FIG. 3A, the substrate 2a is provided on the upper surface of the frame 2, that is, on the main surface of the frame 2 parallel to the XY plane. FIG. 3A illustrates the case where the lead wires 6a and 6b are provided, and the lead wires 6a and 6b are not fixed on the substrate 2a. As the substrate 2a, for example, a glass epoxy substrate can be suitably used.

  As shown in FIG. 3A, the substrate 2a has a hole 2aa, the frame 2 has a hole H1, and the substrate 2a is a pin inserted into the hole 2aa of the substrate 2a and the hole H1 of the frame 2. 8 is fixed to the frame 2. The frame 2 is provided so that the hole H1 corresponds to the hole 2aa of the substrate 2a.

  That is, the substrate 2a is fixed by inserting the parallel pins 8a into the holes H1 of the frame body 2 through the holes 2aa of the substrate 2a as shown in FIG. 3A (b). The parallel pin 8a has a circular cross section in the direction perpendicular to the axial direction and the same diameter.

  Moreover, the hole H1 of the frame 2 may be provided halfway in the Z direction of the frame 2, or may be provided so as to penetrate the frame 2 in the Z direction. 2 is appropriately selected depending on stability at the time of fixing to 2.

  In the sound generator 1 of this embodiment, the effect of the substrate 2a fixed to the frame 2 with the pins 8 will be described. The substrate 2a is fixed to the frame 2 with the pins 8, so that the reflected wave returning from the frame 2 to the vibrating body 3a can be disturbed by disturbing the vibration wave around the substrate 2a. In particular, the vibration wave can be disturbed around the pin 8 fixing the substrate 2a.

  As described above, the substrate 2a is provided on the main surface side of the frame 2 that is the side on which the sound generated by the sound generator 1 propagates, so that the vibration wave induced by the sound signal can easily vibrate the substrate 2a. Thus, the vibration wave propagated around the substrate 2a is likely to be disturbed.

  Accordingly, since the resonance frequencies can be partially unbalanced, the sound pressure peak P at the resonance point can be varied to obtain a good sound pressure frequency characteristic.

  Further, when the glass epoxy substrate is used as described above, the substrate 2a has a structure in which materials having different Young's moduli are dispersed, so that the vibration wave around the substrate 2a can be violently disturbed. Therefore, it is more effective in making the resonance frequencies partially unaligned.

  Moreover, as shown to FIG. 3A (b), although the board | substrate 2a is being fixed to the frame 2 with the parallel pin 8a, it is not restricted to this. The board | substrate 2a can be fixed to the frame 2 with the taper pin 8b as shown to FIG. 3A (c), for example. The taper pin 8b has a circular cross section in a direction perpendicular to the axial direction and is tapered in the axial direction.

  Moreover, the board | substrate 2a can be fixed to the frame 2 with the taper pin 8c as shown to FIG. 3A (d), for example. The taper pin 8c has a circular cross section in a direction perpendicular to the axial direction and is tapered in the axial direction and has a head.

  Thus, the taper pin 8b or 8c has a taper portion larger than the hole 2aa of the substrate 2a, and the substrate 2a is fixed to the frame body 2 by such a large taper portion. It becomes difficult.

  Moreover, the board | substrate 2a can be fixed to the frame 2 with the screw 9 inserted in the hole 2aa of the board | substrate 2a, and the hole H1 of the frame 2 as shown to FIG. 3B. As shown in FIG. 3B, the screw 9 includes a bolt 9a1 and a nut 9a2. In the screw 9, the bolt 9 a 1 is inserted into the hole 2 aa of the substrate 2 a and the hole H 1 of the frame 2, and the bolt 9 a 1 protruding from the hole H 1 fixes the substrate 2 a to the frame 2 with the nut 9 a 2.

  The substrate 2a is fixed to the frame 2 with the screw 9, so that the reflected wave returning from the frame 2 to the vibrating body 3a can be disturbed by disturbing the vibration wave around the substrate 2a. In particular, the vibration wave can be disturbed around the screw 9 fixing the substrate 2a.

  As described above, the substrate 2a is provided on the main surface side of the frame 2 that is the side on which the sound generated by the sound generator 1 propagates, so that the vibration wave induced by the sound signal can easily vibrate the substrate 2a. Thus, the vibration wave propagated around the substrate 2a is likely to be disturbed.

  Further, the screw 9 is composed of a bolt 9a1 and a nut 9a2, and the substrate 2a is fixed to the frame 2. Therefore, the substrate 2a can be stably fixed to the frame 2.

  At least one hole H1 of the frame 2 is provided, but it is preferable to provide two or more holes H1 in order to stably fix the substrate 2a to the frame 2. The holes of the substrate 2a are provided according to the number of holes H1 provided in the frame body 2.

  The pin 8 and the screw 9 are made of, for example, a metal material such as steel, stainless steel, an aluminum alloy, or brass, and are made of, for example, a resin material or a ceramic material. On the other hand, the frame 2 is formed using various materials such as metal and resin. The pin 8 and the screw 9 are preferably made of a material different from that of the frame 2.

  For example, when the frame 2 is formed from a resin material, the pin 8 and the screw 9 are made of a metal material. When the frame 2 is formed from a resin material, the pin 8 and the screw 9 are made of a resin material or a ceramic material. That is, it is preferable to combine the frame body 2 and the pin 8 or the screw 9 so that the materials are different.

  As described above, when the frame 2 and the pin 8 or the screw 9 are made of different materials, the vibration wave propagating on the surface of the frame 2 can be violently disturbed around the frame 2 and the pin 8 or the screw 9. . Therefore, it is more effective in making the resonance frequencies partially unaligned. As a result, the sound pressure peak P at the resonance point varies, and a favorable frequency characteristic of the sound pressure can be obtained.

  Next, an example of the configuration of the acoustic generator 1A according to the embodiment illustrated in FIG. 3C will be described.

  As shown in FIG. 3C, in addition to the sound generator 1 shown in FIG. 3A, the sound generator 1A includes a substrate 2a on the frame 2 and a terminal 2b on the substrate 2a. As shown in FIG. 3C, the substrate 2a has holes 2aa, and the frame 2 has holes H2. Furthermore, the hole H2 is provided with a screw groove H2a that is screwed into the screw 10 inside. The substrate 2a is fixed to the frame 2 with screws 10 inserted into the holes 2aa of the substrate 2a and the holes H2 of the frame 2.

  That is, the substrate 2a is screwed to the frame body 2 with the screw 10 through the screw groove H2a inside the hole H2 of the frame body 2. Moreover, as shown to FIG. 3C (b), the screw 10a does not have a head, but the thread groove is cut over the whole screw (full length). In order to insert the screw 10a into the hole H2 and fasten it, a notch such as a cross shape, a single character shape, or a hexagonal hole is provided at one end.

  The substrate 2a may or may not be provided with a thread groove inside the hole 2aa. When the screw groove is not provided in the hole 2aa of the substrate 2a, the substrate 2a is fixed to the frame 2 with the screw 10 with the diameter of the hole 2aa and the diameter of the screw 10 being substantially the same, for example. Alternatively, the substrate 2a is fixed to the frame body 2 via an adhesive or the like and screwed with the screws 10. Thereby, the board | substrate 2a is fixed to the frame 2 with the screw 10 in the state in which the movement in XY plane was suppressed.

  Further, the terminal 2b is a so-called electrode terminal serving as a connection point from the outside, and at least one or more terminals are provided on the substrate 2a. The terminal 2b is connected to the piezoelectric element 5 by lead wires 6a and 6b. FIG. 3C illustrates a case where two terminals 2b are provided on the substrate 2a, but the number of terminals 2b per one substrate 2a is not limited.

Here, the terminal 2b is made of, for example, a metal material, and is provided on the substrate 2a via an adhesive. In addition, the terminal 2b may be provided on the substrate 2a via an adhesive or the like, for example, a portion serving as a connection point is made of a metal material and a portion in contact with the substrate 2a is made of an insulator.

  As shown in FIG. 3D, the screw 2 a is inserted into the hole H <b> 2 of the frame body 2 through the hole 2 aa of the substrate 2 a. Then, the screw 10a is screwed into the screw groove H2a to screw the substrate 2a to the frame body 2. Accordingly, the substrate 2a is fixed to the frame body 2 when the screw 10a is screwed into the screw groove H2a. Moreover, the hole H2 may be provided halfway in the Z direction of the frame 2 or may be provided so as to penetrate the frame 2 in the Z direction.

  As described above, in the acoustic generator 1A according to the present embodiment, the terminal 2b serving as a connection point from the outside to the lead wires 6a and 6b is provided on the substrate 2a together with the effect of the substrate 2a fixed to the frame 2 with the screws 10. By providing in, the vibration wave which propagates the frame 2 around the terminal 2b can be disturbed. As a result, the height of the peak P can be lowered and the peak width can be widened by making the resonance frequencies partially unaligned.

  Therefore, by providing the terminal 2b on such a substrate 2a, the effect by the substrate 2a and the terminal 2b fixed to the frame 2 with the screw 10 can be obtained synergistically. That is, it is possible to more effectively vary the sound pressure peak P at the resonance point and obtain a favorable frequency characteristic of sound pressure.

  Further, when an electrical signal is input to the terminal 2b, the temperature around the terminal 2b partially rises, so that thermal expansion occurs and the vibration wave is likely to be disturbed. Thereby, the reflected wave returning from the frame 2 to the vibrating body 3a can be disturbed.

  As a result, the resonance frequencies can be partially unbalanced, so that the sound pressure peak P at the resonance point can be varied and the frequency characteristics of the sound pressure can be flattened. That is, it is possible to obtain a favorable frequency characteristic of sound pressure.

  Further, the terminal 2b is provided on the substrate 2a on the main surface side of the frame 2 that is the side on which the sound generated by the sound generator 1 is propagated, so that the vibration wave induced in the sound signal vibrates the terminal 2b. It becomes easy.

  Therefore, the propagating vibration wave is likely to be disturbed around the terminal 2b, and accordingly, the resonance frequencies can be partially not aligned. That is, the sound pressure peak P at the resonance point can be varied to obtain a favorable sound pressure frequency characteristic.

  Furthermore, in the acoustic generator 1A according to the present embodiment, the hole H2 is provided with a screw groove H2a that is screwed into the screw 10, and the substrate 2a is thus provided via the screw groove H2a of the hole H2. When screwed to the frame 2, the vibration wave propagating on the surface of the frame 2 can be violently disturbed around the screw groove H2a of the hole H2a. Therefore, it is more effective in making the resonance frequencies partially unaligned. As a result, the sound pressure peak P at the resonance point varies, and a favorable frequency characteristic of the sound pressure can be obtained.

  Further, the screw 10 is not limited to the screw 10a as shown in FIGS. 3C and 3D. The screw 10 may be, for example, a screw 10b as shown in FIG. The screw 10b includes a head portion 10b1 having a diameter larger than that of the screw portion 10b2. The head 10b1 has a square cross-sectional shape in the axial direction of the screw.

Further, the screw 10 may be, for example, a screw 10c as shown in FIG. The screw 10c includes a head portion 10c1 having a diameter larger than that of the screw portion 10c2. The head 10c1 has a semicircular cross section in the axial direction of the screw. Head 10b1 (10c
In 1), the cross-sectional shape of the screw in the axial direction is not limited to a square shape or a semicircular shape. The substrate 2a is screwed to the frame body 2 using, for example, a wrench that matches the shape of the head of the screw 10.

  Further, the screw 10 may be, for example, a screw 10d as shown in FIG. The screw 10d has a head 10d1 having a circular cross section in a direction perpendicular to the axial direction and a taper in the axial direction, and a diameter larger than the diameter of the threaded portion 10d2.

  As described above, in the screw 10b (10c), the head 10b1 (10c1) and the screw portion 10b2 (10c2) have different diameters, and thus there is a difference in size in the axial direction of the screw. In this way, the vibration wave and its reflected wave can be further disturbed in the part where the size is different, that is, the part where the diameter changes in the axial direction of the screw, so that it is more effective in making the resonance frequency partially uneven. Is. Further, the screw 10d has the same effect, and is more effective in making the resonance frequency partially unaligned.

  Further, the screw 10 only needs to have a different diameter between the screw head and the screw portion. For example, the outer shape of the head may be a square shape or a hexagonal shape in plan view. In such a case, the board | substrate 2a is screwed to the frame 2 using the wrench etc. which match the shape of a head, for example.

  As shown in FIG. 5, the screw 10 may have a notch 11 in the head 10b1 (10c1, 10d1) to rotate and tighten the head. The notch 11 is formed in a groove shape or a hole shape.

  For example, as shown in FIG. 5A, the screw 10 has a notch 11 having a cross shape 11a. For screwing, for example, a plus driver is used.

  Moreover, the screw 10 may have a notch 11b having a single character shape 11b as shown in FIG. 5B, for example, and a screwdriver is used, for example, when screwing.

  Furthermore, as shown in FIG. 5C, for example, the screw 10 may have a notch 11c having a cross shape and one of which is longer. When screwing, the screw 10 is, for example, plus or minus. The driver is used.

  Thus, since the screw 10 has the notch 11 in the head part 10b1 (10c1, 10d1), the part provided with the notch 11 and the notch 11 are provided in the head part 10b (10c1, 10d1). Since the vibration wave and the reflected wave thereof can be further disturbed by the unexposed portion, it is more effective in making the resonance frequency partially unaligned.

  Further, since the above-described screw 10a can be provided with the notch 11 in the upper portion, this brings about the same effect that the resonance frequency is not partially aligned.

  For example, the screw 10 may be provided with a notch 11 in the shape of a hole such as a square hole or a hexagonal hole in the head.

  In FIG. 5, the shape of the screw head is circular when viewed in plan, but the shape is not limited thereto, and may be rectangular or hexagonal when viewed in plan.

Further, in the sound generator 1 according to the embodiment, similarly to the sound generator 1A, the terminal 2b is provided on the substrate 2a, and the terminal 2b and the piezoelectric element 5 are connected by the lead wires 6a and 6b. Good.

  As described above, the sound generators 1 and 1A according to the embodiment include an exciter (piezoelectric element), a vibrating body, and a frame. 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 frame body is provided on an outer peripheral portion of the vibrating body and supports the vibrating body substantially flat. The frame has a hole, and a substrate having a hole corresponding to the hole is fixed to the main surface with a pin or a screw inserted into the hole and the hole.

  Next, modified examples of the substrate 2a or the pins 8 and the screws 9 and 10 will be sequentially described with reference to FIGS. 7A to 7D. 7A to 7D are schematic plan views (No. 1) to (No. 4) showing modifications of the substrate 2a or the pins 8 and the screws 9 and 10. FIG. In each of the drawings shown below, for convenience of description, the pin 8 or the screws 9 and 10 will be described as a generic term using the screw 10. In addition, even if it is the pin 8 and the screw 9, as shown in the following description, there exists an effect similar to the screw 10. FIG.

  First, as illustrated in FIG. 7A, the screw 10 may be provided so as to be non-parallel to the side of the frame 2 in plan view. Specifically, this is a case where the line CL4 connecting the two screws 10 and the center line CL2 of the side of the frame 2 are non-parallel in plan view.

  In such a case, even if the frame 2 is vibrated by being induced by the vibration of the vibrating body 3a, the screw 10 is not parallel to the frame 2, so that the resonance frequency is further shifted in the region of the screw 10. Therefore, since the vibration wave of the frame 2 propagating around the screw 10 can be further disturbed, the reflected wave from the frame 2 to the vibration body 3a can be further disturbed.

  That is, it is possible to obtain a favorable frequency characteristic of sound pressure by making the resonance frequencies partially ununiform and by varying the sound pressure peak P at the resonance point.

  Next, as illustrated in FIG. 7B, the substrate 2 a may be provided so as to protrude outside or inside the frame of the frame body 2. In such a case, even if the frame 2 is vibrated by being induced by the vibration of the vibrating body 3a, the protruding frequency of the substrate 2a is further disturbed because the resonance frequency shifts in the protruding portion of the substrate 2a. be able to. As a result, the reflected wave from the frame 2 to the vibrating body 3a can be further disturbed.

  That is, it is possible to obtain a favorable frequency characteristic of sound pressure by making the resonance frequencies partially ununiform and by varying the sound pressure peak P at the resonance point.

  Further, as shown in FIG. 7C, the substrate 2a may be provided so as to be non-parallel to the sides of the frame body 2 in plan view. Specifically, this is a case where the center line CL2 of the side of the frame 2 and the center line CL3 of the substrate 2a are non-parallel in plan view.

  In such a case, even if the frame 2 is vibrated by being induced by the vibration of the vibrating body 3a, the resonance frequency is further shifted in the region of the substrate 2a because the substrate 2a is not parallel to the frame 2. Therefore, since the vibration wave of the frame 2 propagating around the terminal 2b can be further disturbed, the reflected wave from the frame 2 to the vibration body 3a can be further disturbed.

  That is, it is possible to obtain a favorable frequency characteristic of sound pressure by making the resonance frequencies partially ununiform and by varying the sound pressure peak P at the resonance point.

Further, by being non-parallel in this way, it is possible to give asymmetry to the shape of the composite vibrator. That is, the symmetry of the reflected wave can be reduced, and the resonance frequencies can be partially not aligned.

  7D, the screw 10 is provided so as to be non-parallel to the side of the frame 2 in plan view, and the substrate 2a is not parallel to the side of the frame 2 in plan view. May be provided. Specifically, the line CL4 connecting the two screws 10 and the center line CL2 of the side of the frame 2 are non-parallel in plan view, and the center line CL3 of the substrate 2a and the center line of the side of the frame 2 This is a case where CL2 is non-parallel in plan view.

  Also in this case, for the same reason as in FIG. 7A and FIG. 7C, the resonance frequency is partially unbalanced, and the sound pressure peak P at the resonance point is varied to obtain a favorable sound pressure frequency characteristic. be able to.

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

  The acoustic generator 1 (1A) 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 (1A) and has a function of outputting an audio signal to the sound generator 1 (1A). The sound generator 1 (1A) 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 acoustic generator 1 (1A). 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 only necessary that at least the electronic circuit 60 and the sound generator 1 (1A) 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 acoustic generator 1 (1A) operates as an acoustic 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), a vibrating body, and a frame. 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 frame body is provided on an outer peripheral portion of the vibrating body and supports the vibrating body substantially flat. The frame has a hole, and a substrate having a hole corresponding to the hole is fixed to the main surface with a pin or a screw inserted into the hole and the hole.

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

  In the embodiment described above, 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 body is described as an example. However, such a resin layer may not necessarily be 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 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. 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.

1, 1A, 1B Sound generator 2 Frame 2a Substrate 2aa Hole 2b Terminal 3 Diaphragm 3a Vibrator 5 Exciter (piezoelectric element)
5a, 5b, 5c, 5d Piezoelectric layer 5e Internal electrode layer 5f, 5g Surface electrode layer 5h, 5j External electrode 6a, 6b Lead wire 7 Resin layer 8 Pin 9 Screw (bolt, nut)
DESCRIPTION OF SYMBOLS 10 Screw 11 Cutting 20 Sound generator 30, 40 Case 50 Electronic device 50a Controller 50b Transmission / reception part 50c Key input part 50d Microphone input part 50e Display part 50f Antenna 60 Electronic circuit P Peak H1, H2 Hole H2a Screw groove

Claims (8)

An exciter that vibrates when an electric signal is inputted thereto, the exciter is attached, a vibrating body that vibrates with the exciter by vibration of the exciter, and provided on an outer periphery of the vibrating body, the vibrating body And a frame that supports the substantially flat,
The frame has a hole, and a substrate having a hole corresponding to the hole is fixed to the main surface with the hole and a pin or a screw inserted into the hole. Sound generator. A conductor connected to the exciter and for inputting an electrical signal to the exciter;
The acoustic generator according to claim 1, wherein the substrate is provided with a terminal on the upper surface, which is a connection point to the conducting wire.   The sound generator according to claim 1 or 2, wherein the pin and the screw are made of a material different from that of the frame.   The sound generator according to any one of claims 1 to 3, wherein a thread groove that engages with the screw is provided inside the hole.   The sound generator according to any one of claims 1 to 4, wherein the screw includes a head having a diameter larger than a diameter of the screw portion.   The sound generator according to claim 5, wherein the screw has a notch in the head. The sound generator according to any one of claims 1 to 6,
A sound generation device comprising: a housing that houses the sound generator. The sound generator according to any one of claims 1 to 6,
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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