WO2014024705A1 - Acoustic generator, sound generation device, and electronic device - Google Patents

Acoustic generator, sound generation device, and electronic device Download PDF

Info

Publication number
WO2014024705A1
WO2014024705A1 PCT/JP2013/070352 JP2013070352W WO2014024705A1 WO 2014024705 A1 WO2014024705 A1 WO 2014024705A1 JP 2013070352 W JP2013070352 W JP 2013070352W WO 2014024705 A1 WO2014024705 A1 WO 2014024705A1
Authority
WO
WIPO (PCT)
Prior art keywords
vibrating body
sound
shape
plan
generator
Prior art date
Application number
PCT/JP2013/070352
Other languages
French (fr)
Japanese (ja)
Inventor
弘 二宮
修一 福岡
徳幸 玖島
武 平山
実証 秋枝
Original Assignee
京セラ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 京セラ株式会社 filed Critical 京セラ株式会社
Publication of WO2014024705A1 publication Critical patent/WO2014024705A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2400/00—Loudspeakers
    • H04R2400/03—Transducers capable of generating both sound as well as tactile vibration, e.g. as used in cellular phones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
    • H04R2499/10—General applications
    • H04R2499/11—Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's

Definitions

  • the disclosed embodiment relates to a sound generator, a sound generation device, and an electronic apparatus.
  • piezoelectric speakers are known as small and thin sound generators.
  • a conventional piezoelectric speaker for example, there is one including a rectangular frame, a film stretched on the frame, and a piezoelectric vibration element provided on the film (see, for example, Patent Document 1). ).
  • An object of the present invention is to provide a sound generator, a sound generator, and an electronic device.
  • An acoustic generator includes a frame, a vibration body provided inside the frame, and a piezoelectric vibration element provided on the vibration body, and the vibration body is planar.
  • the shape when viewed is a shape having a plurality of diagonal lines, and the lengths of at least two of the diagonal lines are different from each other.
  • the sound quality can be improved by reducing the fluctuation of the sound pressure in the frequency characteristic of the sound pressure.
  • FIG. 1A is an explanatory diagram in plan view of the sound generator according to the first embodiment.
  • 1B is a cross-sectional view taken along line A-A ′ of FIG. 1A.
  • FIG. 2A is a graph showing an example of the frequency dependence of the sound pressure of the sound generator according to the comparative example.
  • FIG. 2B is a graph showing an example of the frequency dependence of the sound pressure of the sound generator according to the first embodiment.
  • FIG. 3 is an explanatory diagram in plan view of an acoustic generator according to a comparative example.
  • FIG. 4 is a diagram for explaining the sound generator according to the second embodiment.
  • FIG. 5 is a diagram for explaining an electronic apparatus according to the third embodiment.
  • FIG. 6 is an explanatory diagram in plan view of the sound generator according to the fourth embodiment.
  • FIG. 7A is an explanatory diagram in plan view of the sound generator according to the fifth embodiment.
  • FIG. 7B is an explanatory diagram in plan view of the sound generator according to the sixth embodiment.
  • FIG. 8A is an explanatory diagram in plan view of the sound generator according to the seventh embodiment.
  • FIG. 8B is an explanatory diagram viewed from above the acoustic generator according to the eighth embodiment.
  • the acoustic generator 100 is a so-called piezoelectric speaker, and has a configuration for generating sound pressure using a resonance phenomenon of the vibrating body itself. That is, the acoustic generator 100 includes the frame body 10, the film 25, and the piezoelectric vibration element 30 as shown in FIGS. 1A and 1B.
  • the frame body 10 is composed of an upper frame member 11 and a lower frame member 12 having the same shape (rectangular frame shape). And the peripheral part of the film 25 is pinched
  • the vibrating body 20 is configured by a portion (a portion not sandwiched between the upper frame member 11 and the lower frame member 12) of the film 25 that is positioned inside the frame body 10.
  • a piezoelectric vibration element 30 is provided on the vibrating body 20.
  • the acoustic generator 100 of the present embodiment includes a frame body 10, a vibration body 20 provided inside the frame body 10, and two piezoelectric vibration elements 30 provided on the vibration body 20.
  • FIG. 1A is an explanatory view of the acoustic generator 100 according to the first embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (the thickness direction of the vibrating body 20), and FIG. 1A is a cross-sectional view taken along the line AA ′ of FIG. FIG. 1A shows a state where the resin layer 40 is seen through.
  • FIG. 1B in order to facilitate understanding, the sound generator 100 is shown expanded and deformed in the vertical direction.
  • the vibrating body 20 is viewed in plan, it is viewed from the thickness direction of the vibrating body 20 unless otherwise specified.
  • the film 25 in the sound generator 100 of the present embodiment is formed of a resin film, and is a material having a lower elastic modulus and mechanical Q value than a metal plate or the like. For this reason, the vibrating body 20 can be bent and vibrated with a large amplitude, and the resonance peak and dip level in the frequency characteristic of the sound pressure can be reduced. As a result, the frequency characteristics of sound pressure can be flattened, and excellent sound quality can be realized.
  • a resin film such as polyethylene or polyimide can be suitably used, and the thickness can be, for example, 10 to 200 ⁇ m.
  • the film 25 is not limited to a resin film, and can be formed using various known materials such as metal, ceramic, wood, paper, and the like.
  • the frame body 10 plays a role of holding the vibrating body 20 so as to vibrate, and fixes the vibrating body 20 in a state where a predetermined tension is applied to the vibrating body 20. That is, the vibrating body 20 is provided (tensed) inside the frame body 10 in a state where tension is applied. As a result, the acoustic generator 100 including the vibrating body 20 with less deformation such as deflection even when used for a long period of time is obtained.
  • the material of the frame 10 is not particularly limited, and various known materials such as metal, plastic, glass, ceramic, and wood can be used. However, the mechanical strength and the corrosion resistance are excellent. For example, stainless steel can be suitably used. Further, the thickness of the frame body 10 is not particularly limited, and can be appropriately set according to the situation. For example, the thickness can be set to about 100 to 1000 ⁇ m.
  • the piezoelectric vibration element 30 has a plate shape in which the upper and lower main surfaces are rectangular.
  • the piezoelectric vibration element 30 includes a laminate 33 in which four piezoelectric layers 31 (31a, 31b, 31c, 31d) and three internal electrode layers 32 (32a, 32b, 32c) are alternately laminated, Including surface electrode layers 34 and 35 formed on the upper and lower surfaces of the laminate 33, and first to third external electrodes provided at ends in the longitudinal direction (Y-axis direction) of the laminate 33. Yes.
  • the first external electrode 36 is disposed at the end of the laminate 33 in the ⁇ Y direction, and is connected to the surface electrode layers 34 and 35 and the internal electrode layer 32b.
  • a second external electrode 37 and a third external electrode (not shown) are disposed at an end in the + Y direction of the stacked body 33 with a gap in the X-axis direction.
  • the second external electrode 37 is connected to the internal electrode layer 32a, and the third external electrode (not shown) is connected to the internal electrode 32c.
  • Upper and lower end portions of the second external electrode 37 are extended to the upper and lower surfaces of the multilayer body 33 to form folded external electrodes 37a, respectively. These folded external electrodes 37a are formed on the surface of the multilayer body 33. In order not to contact the surface electrode layers 34 and 35, the surface electrode layers 34 and 35 are provided with a predetermined distance therebetween. Similarly, the upper and lower ends of the third external electrode (not shown) are extended to the upper and lower surfaces of the laminated body 33 to form folded external electrodes (not shown), respectively. (Not shown) is extended at a predetermined distance from the surface electrode layers 34 and 35 so as not to contact the surface electrode layers 34 and 35 formed on the surface of the multilayer body 33.
  • the piezoelectric layer 31 (31a, 31b, 31c, 31d) is polarized in the direction indicated by the arrow in FIG. 1B, and when the piezoelectric layers 31a, 31b contract, the piezoelectric layers 31c, 31d extend. In addition, when the piezoelectric layers 31a and 31b extend, a voltage is applied to the first external electrode 36, the second external electrode 37, and the third external electrode so that the piezoelectric layers 31c and 31d contract. .
  • the piezoelectric vibrating element 30 is a bimorph type piezoelectric element, and when an electric signal is input, the piezoelectric vibrating element 30 bends and vibrates in the Z-axis direction so that the amplitude changes in the Y-axis direction.
  • the piezoelectric layer 31 existing piezoelectric ceramics such as lead-free piezoelectric materials such as lead zirconate (PZ), lead zirconate titanate (PZT), Bi layered compounds, and tungsten bronze structure compounds can be used. .
  • the thickness of the piezoelectric layer 31 can be appropriately set according to desired vibration characteristics, but can be set to, for example, 10 to 100 ⁇ m from the viewpoint of low voltage driving.
  • the internal electrode layer 32 can be formed using various existing conductive materials.
  • the internal electrode layer 32 can include a metal component composed of silver and palladium and a material component constituting the piezoelectric layer 31. .
  • the ceramic component constituting the piezoelectric layer 31 in the internal electrode layer 32 it is possible to reduce stress due to the difference in thermal expansion between the piezoelectric layer 31 and the internal electrode layer 32.
  • the internal electrode layer 32 may not include a metal component composed of silver and palladium, and may not include a material component that constitutes the piezoelectric layer 31.
  • the surface electrode layers 34 and 35 and the first to third external electrodes can be formed using various existing conductive materials, and for example, contain a metal component made of silver and a glass component. Can do.
  • the surface electrode layers 34 and 35 and the first to third external electrodes, the piezoelectric layer 31 and the surface electrode layers 34 and 35 and the first to third external electrodes contain the glass component.
  • a strong adhesive force can be obtained with the internal electrode layer 32, but is not limited thereto.
  • the thickness of the adhesive layer 26 is preferably 20 ⁇ m or less, but more preferably 10 ⁇ m or less. When the thickness of the adhesive layer 26 is 20 ⁇ m or less, the vibration of the laminate 33 can be easily transmitted to the film 25.
  • the adhesive for forming the adhesive layer 26 known ones such as an epoxy resin, a silicon resin, and a polyester resin can be used.
  • a method for curing the resin used for the adhesive any method such as thermosetting, photocuring, and anaerobic curing may be used.
  • the acoustic generator 100 of the present embodiment at least a part of the surface of the vibrating body 20 is covered with a coating layer made of the resin layer 40.
  • a resin is filled inside the frame member 11 so that the vibrating body 20 and the piezoelectric vibrating element 30 are embedded, and the resin layer 40 is formed by the filled resin. Is formed.
  • the resin layer 40 an epoxy resin, an acrylic resin, a silicon resin, rubber, or the like can be used.
  • the resin layer 40 preferably covers the piezoelectric vibration element 30 completely from the viewpoint of suppressing a peak or a dip.
  • the piezoelectric vibration element 30 may not be completely covered.
  • the resin layer 40 does not necessarily need to cover the entire vibrating body 20, and in some cases, the resin layer 40 may be provided so as to cover a part of the vibrating body 20.
  • the thickness of the resin layer 40 can be set as appropriate, but is set to about 0.1 mm to 1 mm, for example. In some cases, the resin layer 40 may not be provided.
  • the resonance of the vibrating body 20 can be appropriately damped.
  • the peak or dip in the frequency characteristic of the sound pressure generated due to the resonance phenomenon can be suppressed to a small level, and the fluctuation of the sound pressure due to the frequency can be reduced.
  • the acoustic generator 100 has a trapezoidal shape having two diagonal lines when the vibrating body 20 is viewed in plan, and includes two diagonal lines L1 and L2. The length is different.
  • the shape when the vibrating body 20 is viewed in plan is a shape having a plurality of diagonal lines, and the lengths of at least two diagonal lines among the plurality of diagonal lines are the same. Since they are different from each other, symmetry in the shape of the vibrating body 20 can be reduced.
  • the degenerated vibration mode can be dispersed into a plurality of vibration modes, and one peak in the frequency characteristic of the sound pressure can be dispersed into a plurality of peaks, thereby reducing the level of each peak.
  • the fluctuation of the sound pressure in the frequency characteristic of the sound pressure can be reduced and the sound quality can be improved.
  • the resonance frequency of a plurality of vibration modes coincides, resulting in a problem that the peak level in the frequency characteristic of sound pressure increases.
  • the symmetry in the planar shape of the vibrating body 20 can be reduced, and thereby the resonance frequencies of a plurality of vibration modes can be dispersed.
  • the shape when the vibrating body 20 is viewed in plan is a quadrangle that does not have a 4-fold symmetrical center.
  • the shape of the vibrating body 20 when viewed in plan is not limited to a quadrangle having no 4-fold symmetry center, and an n-gon (n: an integer of 4 or more) having no n-fold symmetry center.
  • n-fold symmetry center means a point where a rotated figure overlaps with a figure before rotation when a two-dimensional figure is rotated by (360 / n) ° around that point.
  • n-gon having no n-fold symmetry center means an n-gon having no n-fold symmetry.
  • the shape when the vibrating body 20 is viewed in plan is a shape that does not have a line-symmetric axis of symmetry. As described above, by further reducing the symmetry in the shape of the vibrating body 20 when viewed in plan, it is possible to further disperse the peaks in the frequency characteristics of the sound pressure and further reduce the fluctuation of the sound pressure.
  • the acoustic generator 100 has a shape having a plurality of diagonal lines when the vibrating body 20 is viewed in plan, and the lengths of at least two of the diagonal lines are different from each other.
  • the shape of the vibrating body 20 when viewed in plan may be a shape that satisfies only the first condition, such as a regular hexagon, for example. The effect of reducing the fluctuation can be obtained.
  • the shape of the vibrating body 20 when viewed in plan may be a shape that satisfies the first condition and the second condition and does not satisfy the third condition, such as a rhombus. It is possible to obtain an effect of reducing fluctuations in sound pressure by dispersing peaks in the frequency characteristics.
  • the degree to which the lengths of the diagonal lines are varied can be appropriately set according to the desired effect. For example, even if the length of the diagonal line is varied by about 0.1%, a corresponding effect can be obtained, but when a certain degree of effect is desired, the length of the diagonal line can be varied by about 1% or more. Desirably, when a great effect is desired, it is desirable to make the length of the diagonal line different by about 10% or more.
  • FIG. 2A is a graph showing an example of the frequency characteristic of the sound pressure of the sound generator 101 according to the comparative example whose shape is shown in FIG. 3, and FIG. 2B is the sound pressure of the sound generator 100 according to the present embodiment. It is a graph which shows an example of a frequency characteristic.
  • FIG. 3 is an explanatory diagram in plan view of the acoustic generator 101 according to the comparative example, and shows a state in which the resin layer 40 is seen through as in FIG. 1A.
  • the horizontal axis indicates the frequency
  • the vertical axis indicates the sound pressure.
  • the acoustic generator 101 is provided with a vibrating body 120 inside a frame 110 having a rectangular shape inside the frame, and when the vibrating body 120 is viewed in plan view.
  • the shape is rectangular. Therefore, the lengths of the two diagonals L10 and L20 of the shape when the vibrating body 120 is viewed in plan are equal.
  • the shape of the vibrating body 120 when viewed from above is a quadrangle having a 4-fold symmetrical center.
  • the shape when the vibrating body 120 is viewed in plan has two symmetrical axes of line symmetry.
  • the shape of the vibrating body 120 when viewed in plan is a structure with very high symmetry.
  • the sound generator 100 has a reduced peak or dip in the frequency characteristic of sound pressure, and fluctuations in sound pressure are reduced. I understand.
  • the piezoelectric vibration element 30 is prepared. First, a binder, a dispersant, a plasticizer, and a solvent are kneaded with the piezoelectric material powder to prepare a slurry.
  • a binder, a dispersant, a plasticizer, and a solvent are kneaded with the piezoelectric material powder to prepare a slurry.
  • the piezoelectric material any of lead-based and non-lead-based materials can be used.
  • the slurry is formed into a sheet to produce a green sheet.
  • a conductor paste is printed on this green sheet to form a conductor pattern to be an internal electrode, three green sheets on which this electrode pattern is formed are stacked, and a green pattern on which no polar pattern is printed Sheets are laminated to produce a laminated molded body.
  • the laminated body 33 is obtained by degreasing and baking the laminated molded body and cutting it into predetermined dimensions.
  • the outer peripheral portion of the multilayer body 33 is processed, and a conductive paste for forming the surface electrode layers 34 and 35 is printed on both main surfaces in the stacking direction of the multilayer body 33.
  • a conductor paste for forming the first to third external electrodes is printed on both end faces in the longitudinal direction (Y-axis direction) of the electrode, and the electrodes are baked at a predetermined temperature. In this way, the piezoelectric vibration element 30 shown in FIGS. 1A and 1B can be obtained.
  • a DC voltage is applied through the first to third external electrodes to polarize the piezoelectric layer 31 of the piezoelectric vibration element 30.
  • Such polarization is performed by applying a DC voltage so as to be in the direction indicated by the arrow in FIG. 1B.
  • the film 25 is prepared, the outer peripheral portion of the film 25 is sandwiched between the frame members 11 and 12, and the film 25 is fixed in a tensioned state. Thereafter, an adhesive to be the adhesive layer 26 is applied to the film 25, the surface electrode 34 side of the piezoelectric vibration element 30 is pressed onto the film 25, and then the adhesive is heated or irradiated with ultraviolet rays. To cure. Then, the resin layer 40 is formed by pouring the uncured resin inside the frame member 11 and curing the resin. In this way, the sound generator 100 of the present embodiment can be manufactured.
  • FIG. 4 is a diagram illustrating an example of the configuration of the sound generation device 70 configured using the sound generator 100 of the first embodiment described above. In FIG. 4, only the components necessary for the description are shown, and the detailed configuration and general components of the sound generator 100 are omitted.
  • the sound generator 70 of the present embodiment is a so-called speaker-like sounding device, and includes, for example, a housing 71 and a sound generator 100 attached to the housing 71 as shown in FIG.
  • the casing 71 has a rectangular parallelepiped box shape, and has an opening 71a on one surface.
  • a casing 71 can be formed using a known material such as plastic, metal, or wood.
  • casing 71 is not limited to a rectangular parallelepiped box shape, For example, it can be set as various shapes, such as cylindrical shape and frustum shape.
  • the sound generator 100 is attached to the opening 71a of the casing 71.
  • the sound generator 100 is the sound generator of the first form described above, and a description of the sound generator 100 is omitted. Since the sound generator 70 having such a configuration generates sound using the sound generator 100 that generates sound with high sound quality, it is possible to generate sound with high sound quality. Moreover, since the sound generator 70 can resonate the sound generated from the sound generator 100 inside the casing 71, for example, the sound pressure in a low frequency band can be increased. In addition, the place where the sound generator 100 is attached can be set freely. Further, the sound generator 100 may be attached to the housing 71 via another object.
  • FIG. 5 is a diagram illustrating an example of the configuration of the electronic device 2 configured using the acoustic generator 100 of the first embodiment described above. In FIG. 5, only the components necessary for the description are shown, and the detailed configuration and general components of the sound generator 100 are omitted.
  • the electronic device 2 includes a housing 200, a sound generator 100 provided in the housing 200, and an electronic circuit connected to the sound generator 100.
  • the electronic device 2 includes an electronic circuit including a control circuit 21, a signal processing circuit 22, and a communication circuit 23, an antenna 24, and a housing 200 that stores these. I have.
  • the communication circuit 23 receives a signal input from the antenna and outputs it to the signal processing circuit 22.
  • the signal processing circuit 22 processes the signal input from the communication circuit 23 to generate an audio signal S and outputs it to the sound generator 100.
  • the sound generator 100 generates sound based on the sound signal S.
  • the control circuit 21 controls the entire electronic device 2 including the signal processing circuit 22 and the communication circuit 23.
  • the electronic device 2 having such a configuration includes the sound generator 100 capable of generating high-quality sound with small fluctuations in sound pressure in the frequency characteristics of sound pressure, the high-quality sound can be obtained. Can be generated.
  • the sound generation device 70 in which the sound generator 100 is attached to the housing 71 may be configured to be attached to the housing 200 of the electronic device 2.
  • the electronic device 2 on which such a sound generator 100 is mounted is not limited to those conventionally known as electronic devices that generate sound, such as a mobile phone, a tablet terminal, a television, and an audio device.
  • the electronic device 2 on which the sound generator 100 is mounted may be an electrical product such as a refrigerator, a microwave oven, a vacuum cleaner, a washing machine, and the like.
  • FIG. 6 is an explanatory view of the acoustic generator 102 according to the fourth embodiment viewed in plan from the thickness direction of the vibrating body 20, and shows a state where the resin layer 40 is seen through, as in FIG. 1A.
  • the sound generator 100 of the first embodiment described above only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
  • the shape when the vibrating body 20 is viewed in plan (the same shape as the shape inside the frame body 10) is a pentagon that is not a regular pentagon.
  • the shape of the vibrating body 20 when viewed in plan is a shape in which one of rectangular corners is cut off to form a pentagon.
  • the shape of the vibrating body 20 when viewed in plan has five diagonal lines L11 to L15, and the lengths of the five diagonal lines are all different.
  • the shape of the vibrating body 20 when viewed in plan is a pentagon having no 5-fold symmetry center.
  • the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry.
  • the shape of the vibrating body 20 in plan view is such that the shape of the frame body 10 is projected inward in a triangular shape at one corner inside the rectangular frame. This is realized by forming the region 13 into a shape.
  • the acoustic generator 102 can solve the contraction of the resonance mode of the vibrating body 20 by making the shape of the vibrating body 20 when viewed from above low in symmetry. Therefore, it is possible to generate high-quality sound in which fluctuations in sound pressure due to frequency are reduced.
  • FIG. 7A is an explanatory diagram of the acoustic generator 103 according to the fifth embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). As in FIG. The state seen through the layer 40 is shown.
  • the sound generator 100 of the first embodiment described above only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
  • the shape when the vibrating body 20 is viewed in plan is a shape having two diagonal lines L31 and L32, and the lengths of the two diagonal lines L31 and L32 are different from each other. Yes. Further, the shape of the vibrating body 20 when viewed in plan is a quadrangle that does not have a 4-fold symmetrical center. Further, the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry.
  • the acoustic generator 103 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
  • FIG. 7B is an explanatory view in plan view of the acoustic generator 104 according to the sixth embodiment from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). Similarly to FIG. The state seen through the layer 40 is shown.
  • the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
  • the acoustic generator 104 has a rhombus shape when the vibrating body 20 is viewed in plan, and the lengths of the two diagonal lines L41 and L42 are different from each other. Further, the shape of the vibrating body 20 when viewed in plan is a quadrangle that has a center of two-fold symmetry and a line-symmetric symmetry axis but does not have a four-fold symmetry axis.
  • the acoustic generator 103 of this example having such a configuration has a lower degree of symmetry of the shape when the vibrating body 20 is viewed in plan, and thus is lower than the acoustic generator of the first embodiment described above. However, it is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics of sound pressure are reduced.
  • FIG. 8A is an explanatory view of the acoustic generator 105 according to the seventh embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). Similarly to FIG. The state seen through the layer 40 is shown.
  • the sound generator 100 of the first embodiment described above only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
  • the acoustic generator 105 has nine diagonal lines L51 to L59 when the vibrating body 20 is viewed in plan, and the nine diagonal lines L51 to L59 are among the nine diagonal lines L51 to L59. At least two diagonals have different lengths.
  • the shape of the vibrating body 20 when viewed in plan is a hexagon that does not have a 6-fold symmetry center.
  • the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry.
  • the acoustic generator 105 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
  • FIG. 8B is an explanatory view in plan view of the acoustic generator 106 according to the eighth embodiment from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20).
  • FIG. 1A FIG. The state seen through the layer 40 is shown.
  • the sound generator 100 of the first embodiment described above only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
  • the acoustic generator 106 has nine diagonal lines L61 to L69 when the vibrating body 20 is viewed in plan, and among the nine diagonal lines L61 to L69, The lengths of at least two diagonal lines are different from each other.
  • the shape of the vibrating body 20 when viewed in plan is a hexagon that does not have a 6-fold symmetry center.
  • the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry.
  • the acoustic generator 106 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
  • the case where the vibration body 20 is viewed in plan is a quadrangle, pentagon, or hexagon.
  • the shape is not limited to this, and may be another polygon.
  • the polygonal vertex may be rounded or the corner of the vertex may be cut off, and any shape that is regarded as a polygon may be used if not strictly.
  • the whole or part of the side of the vibrating body 20 is a curved line.
  • piezoelectric vibration elements 30 are disposed on the vibrating body 20, but one or three or more piezoelectric vibration elements 30 may be disposed.
  • the piezoelectric vibration element 30 has a rectangular shape in plan view, it may have another shape such as an elliptical shape.
  • the piezoelectric vibration element 30 a so-called bimorph type laminated type is exemplified, but the piezoelectric vibration element 30 is not limited to this.
  • the same effect can be obtained by using a unimorph type piezoelectric vibration element in which a plate made of metal or the like is attached to one main surface of a piezoelectric vibration element that expands and contracts in a plane direction instead of a bimorph type piezoelectric vibration element. Can be obtained.
  • piezoelectric vibration elements that stretch and vibrate in the plane direction may be provided on both surfaces of the film 25, or unimorph type or bimorph type piezoelectric vibration elements may be provided on both surfaces of the film 25.

Abstract

Provided are an acoustic generator that is capable of generating high-quality sound with little frequency-related fluctuation of sound pressure, a sound generation device, and an electronic device. This acoustic generator is equipped with a frame body, a vibrating body that is provided on the inner side of the frame body, and a piezoelectric vibrating body that is provided on the vibrating body. For the acoustic generator, the vibrating body has a shape with multiple diagonals when seen in a plan view, and at least two diagonals among the multiple diagonals have different lengths from each other. The sound generation device and the electronic device utilize the acoustic generator.

Description

音響発生器、音響発生装置および電子機器SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
　開示の実施形態は、音響発生器、音響発生装置および電子機器に関する。 The disclosed embodiment relates to a sound generator, a sound generation device, and an electronic apparatus.
　従来、圧電スピーカーは、小型で薄型の音響発生器として知られている。従来の圧電スピーカーとしては、たとえば、矩形形状の枠体と、枠体に張設されたフィルムと、フィルム上に設けられた圧電振動素子とを備えたものがある（例えば、特許文献１を参照）。 Conventionally, piezoelectric speakers are known as small and thin sound generators. As a conventional piezoelectric speaker, for example, there is one including a rectangular frame, a film stretched on the frame, and a piezoelectric vibration element provided on the film (see, for example, Patent Document 1). ).
特開２０１２－６０５１３号公報JP 2012-60513 A
　しかしながら、特許文献１に開示された圧電スピーカーでは、共振現象に起因して、音圧の周波数特性においてピーク（周囲よりも音圧が高い部分）やディップ（周囲よりも音圧が低い部分）が生じてしまい、周波数によって音圧が大きく変化してしまうという問題があった。 However, in the piezoelectric speaker disclosed in Patent Document 1, due to the resonance phenomenon, there is a peak (a portion where the sound pressure is higher than the surroundings) or a dip (a portion where the sound pressure is lower than the surroundings) in the frequency characteristics of the sound pressure. There arises a problem that the sound pressure changes greatly depending on the frequency.
　実施形態の一態様は、このような課題に鑑みてなされたものであって、音圧の周波数特性におけるピークやディップのレベルを小さくして音圧の変動を低減し、音質を向上させることのできる音響発生器、音響発生装置および電子機器を提供することを目的とする。 One aspect of the embodiment has been made in view of such a problem, and it is possible to reduce the fluctuation of the sound pressure by reducing the peak or dip level in the frequency characteristic of the sound pressure, thereby improving the sound quality. An object of the present invention is to provide a sound generator, a sound generator, and an electronic device.
　実施形態の一態様に係る音響発生器は、枠体と、該枠体の内側に設けられた振動体と、該振動体上に設けられた圧電振動素子と、を備え、前記振動体を平面視したときの形状が、複数の対角線を有する形状であり、前記複数の対角線のうち、少なくとも２つの対角線の長さが互いに異なる。 An acoustic generator according to an aspect of an embodiment includes a frame, a vibration body provided inside the frame, and a piezoelectric vibration element provided on the vibration body, and the vibration body is planar. The shape when viewed is a shape having a plurality of diagonal lines, and the lengths of at least two of the diagonal lines are different from each other.
　実施形態の一態様の音響発生器によれば、音圧の周波数特性における音圧の変動を低減して、音質を向上させることができる。 According to the acoustic generator of one aspect of the embodiment, the sound quality can be improved by reducing the fluctuation of the sound pressure in the frequency characteristic of the sound pressure.
図１Ａは、第１の実施形態に係る音響発生器の平面視による説明図である。FIG. 1A is an explanatory diagram in plan view of the sound generator according to the first embodiment. 図１Ｂは、図１ＡのＡ－Ａ’線断面図である。1B is a cross-sectional view taken along line A-A ′ of FIG. 1A. 図２Ａは、比較例に係る音響発生器の音圧の周波数依存性の一例を示すグラフである。FIG. 2A is a graph showing an example of the frequency dependence of the sound pressure of the sound generator according to the comparative example. 図２Ｂは、第１の実施形態に係る音響発生器の音圧の周波数依存性の一例を示すグラフである。FIG. 2B is a graph showing an example of the frequency dependence of the sound pressure of the sound generator according to the first embodiment. 図３は、比較例に係る音響発生器の平面視による説明図である。FIG. 3 is an explanatory diagram in plan view of an acoustic generator according to a comparative example. 図４は、第２の実施形態に係る音響発生装置を説明するための図である。FIG. 4 is a diagram for explaining the sound generator according to the second embodiment. 図５は、第３の実施形態に係る電子機器を説明するための図である。FIG. 5 is a diagram for explaining an electronic apparatus according to the third embodiment. 図６は、第４の実施形態に係る音響発生器の平面視による説明図である。FIG. 6 is an explanatory diagram in plan view of the sound generator according to the fourth embodiment. 図７Ａは、第５の実施形態に係る音響発生器の平面視による説明図である。FIG. 7A is an explanatory diagram in plan view of the sound generator according to the fifth embodiment. 図７Ｂは、第６の実施形態に係る音響発生器の平面視による説明図である。FIG. 7B is an explanatory diagram in plan view of the sound generator according to the sixth embodiment. 図８Ａは、第７の実施形態に係る音響発生器の平面視による説明図である。FIG. 8A is an explanatory diagram in plan view of the sound generator according to the seventh embodiment. 図８Ｂは、第８の実施形態に係る音響発生器の平面視による説明図である。FIG. 8B is an explanatory diagram viewed from above the acoustic generator according to the eighth embodiment.
　以下、添付図面を参照して、本願の開示する音響発生器、音響発生装置および電子機器の実施形態について説明する。なお、以下に示す各実施形態によりこの発明が限定されるものではない。 Hereinafter, embodiments of a sound generator, a sound generator, and an electronic device disclosed in the present application will be described with reference to the accompanying drawings. In addition, this invention is not limited by each embodiment shown below.
（第１の実施形態）
　第１の実施形態に係る音響発生器１００の構成について、図１Ａおよび図１Ｂを用いて説明する。 (First embodiment)
The configuration of the sound generator 100 according to the first embodiment will be described with reference to FIGS. 1A and 1B.
　第１の実施形態に係る音響発生器１００は、いわゆる圧電スピーカーと呼ばれるものであり、振動体自体の共振現象を用いて音圧を発生させる構成を備える。すなわち、音響発生器１００は、図１Ａおよび図１Ｂに示すように、枠体１０と、フィルム２５と、圧電振動素子３０とを有している。 The acoustic generator 100 according to the first embodiment is a so-called piezoelectric speaker, and has a configuration for generating sound pressure using a resonance phenomenon of the vibrating body itself. That is, the acoustic generator 100 includes the frame body 10, the film 25, and the piezoelectric vibration element 30 as shown in FIGS. 1A and 1B.
　図１Ｂに示すように、枠体１０は、同一の形状（矩形の枠状）を有する上枠部材１１および下枠部材１２によって構成されている。そして、フィルム２５の周縁部が、上枠部材１１および下枠部材１２によって挟まれて固定されており、フィルム２５における枠体１０の内側に位置する部分が、振動可能な状態で枠体１０に支持されている。このようにして、フィルム２５のうち枠体１０の内側に位置する部分（上枠部材１１および下枠部材１２によって挟まれていない部分）によって振動体２０が構成されている。そして、圧電振動素子３０が振動体２０上に設けられている。 As shown in FIG. 1B, the frame body 10 is composed of an upper frame member 11 and a lower frame member 12 having the same shape (rectangular frame shape). And the peripheral part of the film 25 is pinched | interposed and fixed by the upper frame member 11 and the lower frame member 12, and the part located inside the frame 10 in the film 25 is in the frame 10 in the state which can vibrate. It is supported. In this way, the vibrating body 20 is configured by a portion (a portion not sandwiched between the upper frame member 11 and the lower frame member 12) of the film 25 that is positioned inside the frame body 10. A piezoelectric vibration element 30 is provided on the vibrating body 20.
　すなわち、本実施形態の音響発生器１００は、枠体１０と、この枠体１０の内側に設けられた振動体２０と、この振動体２０上に設けられた２つの圧電振動素子３０とを備えている。なお、図１Ａは、第１の実施形態に係る音響発生器１００を振動体２０の主面に垂直な方向（振動体２０の厚み方向）から平面視した説明図であり、図１Ｂは、図１ＡのＡ－Ａ’線断面図である。なお、図１Ａにおいては、樹脂層４０を透視した状態を示している。また、図１Ｂにおいては、理解を容易にするために、音響発生器１００を上下方向に拡張してデフォルメして示している。なお、本明細書において、振動体２０を平面視する場合には、特に記載がない限り、振動体２０の厚み方向から平面視するものとする。 That is, the acoustic generator 100 of the present embodiment includes a frame body 10, a vibration body 20 provided inside the frame body 10, and two piezoelectric vibration elements 30 provided on the vibration body 20. ing. 1A is an explanatory view of the acoustic generator 100 according to the first embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (the thickness direction of the vibrating body 20), and FIG. 1A is a cross-sectional view taken along the line AA ′ of FIG. FIG. 1A shows a state where the resin layer 40 is seen through. Moreover, in FIG. 1B, in order to facilitate understanding, the sound generator 100 is shown expanded and deformed in the vertical direction. In the present specification, when the vibrating body 20 is viewed in plan, it is viewed from the thickness direction of the vibrating body 20 unless otherwise specified.
　本実施形態の音響発生器１００におけるフィルム２５は、樹脂フィルムにより形成されており、金属板などに比べて弾性率および機械的なＱ値の低い材料としている。このため、振動体２０を大きな振幅で屈曲振動させ、音圧の周波数特性における共振ピークやディップのレベルを小さくすることができる。その結果、音圧の周波数特性を平坦化することができ、優れた音質を実現させることが可能である。 The film 25 in the sound generator 100 of the present embodiment is formed of a resin film, and is a material having a lower elastic modulus and mechanical Q value than a metal plate or the like. For this reason, the vibrating body 20 can be bent and vibrated with a large amplitude, and the resonance peak and dip level in the frequency characteristic of the sound pressure can be reduced. As a result, the frequency characteristics of sound pressure can be flattened, and excellent sound quality can be realized.
　フィルム２５を形成する樹脂フィルムは、ポリエチレン、ポリイミド等の樹脂フィルムを好適に用いることができ、厚みとしては、たとえば、１０～２００μｍとすることができる。なお、フィルム２５は、樹脂フィルムに限定されるものではなく、例えば、金属，セラミック，木材，紙など、種々の既知の材料を用いて形成することができる。 As the resin film forming the film 25, a resin film such as polyethylene or polyimide can be suitably used, and the thickness can be, for example, 10 to 200 μm. The film 25 is not limited to a resin film, and can be formed using various known materials such as metal, ceramic, wood, paper, and the like.
　枠体１０は、振動体２０を振動可能に保持する役割を担っており、振動体２０に所定の張力を付与した状態で振動体２０を固定している。すなわち、振動体２０は、枠体１０の内側に、張力が加えられた状態で設けられている（張られている）。これにより、長期間使用してもたわみなどの変形の少ない振動体２０を備えた音響発生器１００となる。 The frame body 10 plays a role of holding the vibrating body 20 so as to vibrate, and fixes the vibrating body 20 in a state where a predetermined tension is applied to the vibrating body 20. That is, the vibrating body 20 is provided (tensed) inside the frame body 10 in a state where tension is applied. As a result, the acoustic generator 100 including the vibrating body 20 with less deformation such as deflection even when used for a long period of time is obtained.
　枠体１０の材質は、特に限定されるものではなく、金属，プラスチック，ガラス，セラミック，木材など、既知の種々の材料を用いることができるが、機械的強度および耐食性に優れているという理由から、たとえば、ステンレスを好適に用いることができる。また、枠体１０の厚さも、特に限定されるものではなく、状況に応じて適宜設定することができるが、例えば、１００～１０００μｍ程度に設定することができる。 The material of the frame 10 is not particularly limited, and various known materials such as metal, plastic, glass, ceramic, and wood can be used. However, the mechanical strength and the corrosion resistance are excellent. For example, stainless steel can be suitably used. Further, the thickness of the frame body 10 is not particularly limited, and can be appropriately set according to the situation. For example, the thickness can be set to about 100 to 1000 μm.
　圧電振動素子３０は、上下の主面が矩形の板状の形状を有している。圧電振動素子３０は、４層の圧電体層３１（３１ａ，３１ｂ，３１ｃ，３１ｄ）と３層の内部電極層３２（３２ａ，３２ｂ，３２ｃ）とを交互に積層してなる積層体３３と、この積層体３３の上下両面に形成された表面電極層３４、３５と、積層体３３の長手方向（Ｙ軸方向）の端部に設けられた、第１～第３の外部電極とを含んでいる。 The piezoelectric vibration element 30 has a plate shape in which the upper and lower main surfaces are rectangular. The piezoelectric vibration element 30 includes a laminate 33 in which four piezoelectric layers 31 (31a, 31b, 31c, 31d) and three internal electrode layers 32 (32a, 32b, 32c) are alternately laminated, Including surface electrode layers 34 and 35 formed on the upper and lower surfaces of the laminate 33, and first to third external electrodes provided at ends in the longitudinal direction (Y-axis direction) of the laminate 33. Yes.
　第１の外部電極３６は、積層体３３の－Ｙ方向の端部に配置されており、表面電極層３４、３５と、内部電極層３２ｂとに接続されている。積層体３３の＋Ｙ方向の端部には、第２の外部電極３７と、第３の外部電極（図示せず）とが、Ｘ軸方向に間隔を開けて配置されている。第２の外部電極３７は、内部電極層３２ａに接続されており、第３の外部電極（図示せず）は、内部電極３２ｃに接続されている。 The first external electrode 36 is disposed at the end of the laminate 33 in the −Y direction, and is connected to the surface electrode layers 34 and 35 and the internal electrode layer 32b. A second external electrode 37 and a third external electrode (not shown) are disposed at an end in the + Y direction of the stacked body 33 with a gap in the X-axis direction. The second external electrode 37 is connected to the internal electrode layer 32a, and the third external electrode (not shown) is connected to the internal electrode 32c.
　第２の外部電極３７の上下端部は、積層体３３の上下面まで延設されてそれぞれ折返外部電極３７ａが形成されており、これらの折返外部電極３７ａは、積層体３３の表面に形成された表面電極層３４、３５に接触しないように、表面電極層３４、３５との間で所定の距離を隔てて延設されている。同様に、第３の外部電極（図示せず）の上下端部は、積層体３３の上下面まで延設されてそれぞれ折返外部電極（図示せず）が形成されており、これらの折返外部電極（図示せず）は、積層体３３の表面に形成された表面電極層３４、３５に接触しないように、表面電極層３４、３５との間で所定の距離を隔てて延設されている。 Upper and lower end portions of the second external electrode 37 are extended to the upper and lower surfaces of the multilayer body 33 to form folded external electrodes 37a, respectively. These folded external electrodes 37a are formed on the surface of the multilayer body 33. In order not to contact the surface electrode layers 34 and 35, the surface electrode layers 34 and 35 are provided with a predetermined distance therebetween. Similarly, the upper and lower ends of the third external electrode (not shown) are extended to the upper and lower surfaces of the laminated body 33 to form folded external electrodes (not shown), respectively. (Not shown) is extended at a predetermined distance from the surface electrode layers 34 and 35 so as not to contact the surface electrode layers 34 and 35 formed on the surface of the multilayer body 33.
　そして、圧電体層３１（３１ａ，３１ｂ，３１ｃ，３１ｄ）は、図１Ｂに矢印で示す向きに分極されており、圧電体層３１ａ、３１ｂが縮む場合には圧電体層３１ｃ、３１ｄが延びるように、そして、圧電体層３１ａ、３１ｂが延びる場合には圧電体層３１ｃ、３１ｄが縮むように、第１の外部電極３６、第２の外部電極３７および第３の外部電極に電圧が印加される。このように、圧電振動素子３０は、バイモルフ型の圧電素子であり、電気信号が入力されるとＹ軸方向に振幅が変化するようにＺ軸方向に屈曲振動する。 The piezoelectric layer 31 (31a, 31b, 31c, 31d) is polarized in the direction indicated by the arrow in FIG. 1B, and when the piezoelectric layers 31a, 31b contract, the piezoelectric layers 31c, 31d extend. In addition, when the piezoelectric layers 31a and 31b extend, a voltage is applied to the first external electrode 36, the second external electrode 37, and the third external electrode so that the piezoelectric layers 31c and 31d contract. . Thus, the piezoelectric vibrating element 30 is a bimorph type piezoelectric element, and when an electric signal is input, the piezoelectric vibrating element 30 bends and vibrates in the Z-axis direction so that the amplitude changes in the Y-axis direction.
　圧電体層３１としては、ジルコン酸鉛（ＰＺ）、チタン酸ジルコン酸鉛（ＰＺＴ）、Ｂｉ層状化合物、タングステンブロンズ構造化合物等の非鉛系圧電体材料等、既存の圧電セラミックスを用いることができる。圧電体層３１の厚みは、所望の振動特性に応じて適宜設定することができるが、例えば、低電圧駆動という観点から、１０～１００μｍとすることができる。 As the piezoelectric layer 31, existing piezoelectric ceramics such as lead-free piezoelectric materials such as lead zirconate (PZ), lead zirconate titanate (PZT), Bi layered compounds, and tungsten bronze structure compounds can be used. . The thickness of the piezoelectric layer 31 can be appropriately set according to desired vibration characteristics, but can be set to, for example, 10 to 100 μm from the viewpoint of low voltage driving.
　内部電極層３２は、既存の種々の導体材料を用いて形成することができるが、例えば、銀とパラジウムからなる金属成分と圧電体層３１を構成する材料成分を包含するものとすることができる。内部電極層３２に圧電体層３１を構成するセラミック成分を含有させることによって、圧電体層３１と内部電極層３２との熱膨張差による応力を低減することができる。なお、内部電極層３２は、銀とパラジウムからなる金属成分を含まなくてもよく、また、圧電体層３１を構成する材料成分を含まなくてもよい。 The internal electrode layer 32 can be formed using various existing conductive materials. For example, the internal electrode layer 32 can include a metal component composed of silver and palladium and a material component constituting the piezoelectric layer 31. . By including the ceramic component constituting the piezoelectric layer 31 in the internal electrode layer 32, it is possible to reduce stress due to the difference in thermal expansion between the piezoelectric layer 31 and the internal electrode layer 32. The internal electrode layer 32 may not include a metal component composed of silver and palladium, and may not include a material component that constitutes the piezoelectric layer 31.
　表面電極層３４、３５および第１～第３の外部電極は、既存の種々の導体材料を用いて形成することができるが、例えば、銀からなる金属成分およびガラス成分を含有するものとすることができる。このように、表面電極層３４、３５および第１～第３の外部電極がガラス成分を含有することによって、表面電極層３４、３５および第１～第３の外部電極と、圧電体層３１および内部電極層３２との間に強固な密着力を得ることができるが、これに限定されるものではない。 The surface electrode layers 34 and 35 and the first to third external electrodes can be formed using various existing conductive materials, and for example, contain a metal component made of silver and a glass component. Can do. Thus, the surface electrode layers 34 and 35 and the first to third external electrodes, the piezoelectric layer 31 and the surface electrode layers 34 and 35 and the first to third external electrodes contain the glass component. A strong adhesive force can be obtained with the internal electrode layer 32, but is not limited thereto.
　また、圧電振動素子３０のフィルム２５側の主面とフィルム２５とが接着剤層２６で接合されている。接着剤層２６の厚みは、２０μｍ以下が望ましいが、１０μｍ以下が更に望ましい。接着剤層２６の厚みが２０μｍ以下である場合には、積層体３３の振動をフィルム２５に伝えやすくなる。 Further, the main surface of the piezoelectric vibration element 30 on the film 25 side and the film 25 are joined by the adhesive layer 26. The thickness of the adhesive layer 26 is preferably 20 μm or less, but more preferably 10 μm or less. When the thickness of the adhesive layer 26 is 20 μm or less, the vibration of the laminate 33 can be easily transmitted to the film 25.
　接着剤層２６を形成するための接着剤としては、エポキシ系樹脂、シリコン樹脂、ポリエステル系樹脂などの公知のものを使用できる。接着剤に使用する樹脂の硬化方法は、熱硬化、光硬化や嫌気性硬化等のいずれの方法を用いても良い。 As the adhesive for forming the adhesive layer 26, known ones such as an epoxy resin, a silicon resin, and a polyester resin can be used. As a method for curing the resin used for the adhesive, any method such as thermosetting, photocuring, and anaerobic curing may be used.
　さらに、本実施形態の音響発生器１００は、振動体２０の表面の少なくとも一部が、樹脂層４０からなる被覆層によって被覆されている。詳細には、本実施形態の音響発生器１００は、振動体２０および圧電振動素子３０を埋設するように、枠部材１１の内側に樹脂が充填されており、充填された樹脂によって樹脂層４０が形成されている。 Furthermore, in the acoustic generator 100 of the present embodiment, at least a part of the surface of the vibrating body 20 is covered with a coating layer made of the resin layer 40. Specifically, in the acoustic generator 100 of the present embodiment, a resin is filled inside the frame member 11 so that the vibrating body 20 and the piezoelectric vibrating element 30 are embedded, and the resin layer 40 is formed by the filled resin. Is formed.
　樹脂層４０には、エポキシ系樹脂、アクリル系樹脂、シリコン系樹脂やゴムなどを採用できる。また、樹脂層４０は、ピークやディップを抑制する観点から、圧電振動素子３０を完全に覆うのが好ましが、圧電振動素子３０を完全に覆わなくても構わない。さらに、樹脂層４０は、必ずしも振動体２０の全体を覆う必要はなく、場合によっては、振動体２０の一部を覆うように樹脂層４０を設けても構わない。なお、樹脂層４０の厚さは、適宜設定することができるが、例えば、０．１ｍｍ～１ｍｍ程度に設定される。また、場合によっては、樹脂層４０を設けなくても構わない。 For the resin layer 40, an epoxy resin, an acrylic resin, a silicon resin, rubber, or the like can be used. In addition, the resin layer 40 preferably covers the piezoelectric vibration element 30 completely from the viewpoint of suppressing a peak or a dip. However, the piezoelectric vibration element 30 may not be completely covered. Furthermore, the resin layer 40 does not necessarily need to cover the entire vibrating body 20, and in some cases, the resin layer 40 may be provided so as to cover a part of the vibrating body 20. The thickness of the resin layer 40 can be set as appropriate, but is set to about 0.1 mm to 1 mm, for example. In some cases, the resin layer 40 may not be provided.
　このように、樹脂層４０を設けることによって、振動体２０の共振を適度にダンピングすることができる。これによって、共振現象に起因して発生する、音圧の周波数特性におけるピークやディップを小さく抑制することができ、周波数による音圧の変動を低減することができる。 Thus, by providing the resin layer 40, the resonance of the vibrating body 20 can be appropriately damped. As a result, the peak or dip in the frequency characteristic of the sound pressure generated due to the resonance phenomenon can be suppressed to a small level, and the fluctuation of the sound pressure due to the frequency can be reduced.
　上述してきた本実施形態に係る音響発生器１００は、図１Ａに示すように、振動体２０を平面視したときの形状が２つの対角線を有する台形状であり、且つ２つの対角線Ｌ１，Ｌ２の長さが異なる。このように、本実施形態に係る音響発生器１００は、振動体２０を平面視したときの形状が、複数の対角線を有する形状であり、複数の対角線のうち、少なくとも２つの対角線の長さが互いに異なることから、振動体２０の形状における対称性を低下させることができる。これにより、縮退した振動モードを複数の振動モードに分散させ、音圧の周波数特性における１つのピークを複数のピークに分散させて、１つ１つのピークのレベルを小さくすることができる。これにより、音圧の周波数特性における音圧の変動を小さくして、音質を向上させることができる。 As shown in FIG. 1A, the acoustic generator 100 according to the present embodiment described above has a trapezoidal shape having two diagonal lines when the vibrating body 20 is viewed in plan, and includes two diagonal lines L1 and L2. The length is different. As described above, in the sound generator 100 according to the present embodiment, the shape when the vibrating body 20 is viewed in plan is a shape having a plurality of diagonal lines, and the lengths of at least two diagonal lines among the plurality of diagonal lines are the same. Since they are different from each other, symmetry in the shape of the vibrating body 20 can be reduced. Thereby, the degenerated vibration mode can be dispersed into a plurality of vibration modes, and one peak in the frequency characteristic of the sound pressure can be dispersed into a plurality of peaks, thereby reducing the level of each peak. Thereby, the fluctuation of the sound pressure in the frequency characteristic of the sound pressure can be reduced and the sound quality can be improved.
　すなわち、対称性の高い平面形状を有する振動体では、複数の振動モードの共振周波数が一致して、音圧の周波数特性におけるピークのレベルが大きくなってしまうという問題が発生する。これに対し、本実施形態の音響発生器１００では、振動体２０の平面形状における対称性を低下させ、これによって、複数の振動モードの共振周波数を分散させることができる。 That is, in a vibrating body having a highly symmetric planar shape, the resonance frequency of a plurality of vibration modes coincides, resulting in a problem that the peak level in the frequency characteristic of sound pressure increases. On the other hand, in the acoustic generator 100 of this embodiment, the symmetry in the planar shape of the vibrating body 20 can be reduced, and thereby the resonance frequencies of a plurality of vibration modes can be dispersed.
　また、本実施形態の音響発生器１００は、振動体２０を平面視したときの形状を、４回対称の中心を持たない四角形としている。このように、振動体２０を平面視したときの形状における対称性を更に低下させることにより、音圧の周波数特性において、ピークをさらに分散させて、音圧の変動をさらに小さくすることができる。なお、“４回対称の中心”とは、その点を中心として、２次元の図形を（３６０／４）°＝９０°回転させたときに、回転後の図形が回転前の図形と重なる点を意味する。そして、“４回対称の中心を持たない四角形”とは、４回対称ではない四角形を意味する。 Further, in the acoustic generator 100 of the present embodiment, the shape when the vibrating body 20 is viewed in plan is a quadrangle that does not have a 4-fold symmetrical center. As described above, by further reducing the symmetry in the shape of the vibrating body 20 when viewed in plan, it is possible to further disperse the peaks in the frequency characteristics of the sound pressure and further reduce the fluctuation of the sound pressure. The “four-fold symmetry center” is a point where a rotated figure overlaps with a figure before rotation when a two-dimensional figure is rotated by (360/4) ° = 90 ° around that point. Means. “A quadrangle that does not have a four-fold symmetry center” means a quadrangle that is not four-fold symmetric.
　なお、４回対称の中心を持たない四角形に限らず、振動体２０を平面視したときの形状を、ｎ回対称の中心を持たないｎ角形（ｎ：４以上の整数）とすることにより、同様に、音圧の周波数特性において、ピークをさらに分散させて、音圧の変動をさらに小さくすることができる。なお、“ｎ回対称の中心”とは、その点を中心として、２次元の図形を（３６０／ｎ）°回転させたときに、回転後の図形が回転前の図形と重なる点を意味する。そして、“ｎ回対称の中心を持たないｎ角形”とは、ｎ回対称ではないｎ角形を意味する。 Note that the shape of the vibrating body 20 when viewed in plan is not limited to a quadrangle having no 4-fold symmetry center, and an n-gon (n: an integer of 4 or more) having no n-fold symmetry center. Similarly, in the frequency characteristics of sound pressure, it is possible to further disperse peaks and further reduce sound pressure fluctuations. The “n-fold symmetry center” means a point where a rotated figure overlaps with a figure before rotation when a two-dimensional figure is rotated by (360 / n) ° around that point. . The “n-gon having no n-fold symmetry center” means an n-gon having no n-fold symmetry.
　さらに、本実施形態の音響発生器１００は、振動体２０を平面視したときの形状を、線対称の対称軸を持たない形状としている。このように、振動体２０を平面視したときの形状における対称性を更に低下させることにより、音圧の周波数特性において、ピークをさらに分散させて、音圧の変動をさらに小さくすることができる。 Furthermore, in the acoustic generator 100 of the present embodiment, the shape when the vibrating body 20 is viewed in plan is a shape that does not have a line-symmetric axis of symmetry. As described above, by further reducing the symmetry in the shape of the vibrating body 20 when viewed in plan, it is possible to further disperse the peaks in the frequency characteristics of the sound pressure and further reduce the fluctuation of the sound pressure.
　なお、本実施形態の音響発生器１００は、振動体２０を平面視したときの形状を、複数の対角線を有する形状であり、複数の対角線のうち、少なくとも２つの対角線の長さが互いに異なるという第１の条件と、ｎ回対称の中心を持たないｎ角形（ｎ：４以上の整数）であるという第２の条件と、線対称の対称軸を持たない形状であるという第３の条件との、３つの条件を全て満足する形状としたが、これに限定されるものではない。振動体２０を平面視したときの形状を、例えば正６角形のような、第１の条件のみを満足する形状としても良く、それだけでも、音圧の周波数特性においてピークを分散させて音圧の変動を小さくするという効果を得ることができる。また、振動体２０を平面視したときの形状を、例えば菱形のような、第１の条件および第２の条件を満足し第３の条件を満足しない形状としても良く、それだけでも、音圧の周波数特性においてピークを分散させて音圧の変動を小さくするという効果を得ることができる。また、対角線の長さを異ならせる程度については、所望する効果の大きさに応じて適宜設定することができる。例えば、対角線の長さを０．１％程度異ならせた場合でも相応の効果を得ることができるが、ある程度の効果を所望する場合には、対角線の長さを１％程度以上異ならせるのが望ましく、大きな効果を所望する場合には、対角線の長さを１０％程度以上異ならせるのが望ましい。 The acoustic generator 100 according to the present embodiment has a shape having a plurality of diagonal lines when the vibrating body 20 is viewed in plan, and the lengths of at least two of the diagonal lines are different from each other. A first condition, a second condition of an n-gon (n: an integer of 4 or more) having no n-fold symmetry center, and a third condition of a shape having no line-symmetric symmetry axis; However, the present invention is not limited to this shape. The shape of the vibrating body 20 when viewed in plan may be a shape that satisfies only the first condition, such as a regular hexagon, for example. The effect of reducing the fluctuation can be obtained. Further, the shape of the vibrating body 20 when viewed in plan may be a shape that satisfies the first condition and the second condition and does not satisfy the third condition, such as a rhombus. It is possible to obtain an effect of reducing fluctuations in sound pressure by dispersing peaks in the frequency characteristics. In addition, the degree to which the lengths of the diagonal lines are varied can be appropriately set according to the desired effect. For example, even if the length of the diagonal line is varied by about 0.1%, a corresponding effect can be obtained, but when a certain degree of effect is desired, the length of the diagonal line can be varied by about 1% or more. Desirably, when a great effect is desired, it is desirable to make the length of the diagonal line different by about 10% or more.
　図２Ａは、図３に形状を示した比較例に係る音響発生器１０１の音圧の周波数特性の一例を示すグラフであり、図２Ｂは、本実施形態に係る音響発生器１００の音圧の周波数特性の一例を示すグラフである。また、図３は、比較例に係る音響発生器１０１の平面視による説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、図２Ａ，図２Ｂに示すグラフにおいては、横軸は周波数を示しており、縦軸は音圧を示している。 2A is a graph showing an example of the frequency characteristic of the sound pressure of the sound generator 101 according to the comparative example whose shape is shown in FIG. 3, and FIG. 2B is the sound pressure of the sound generator 100 according to the present embodiment. It is a graph which shows an example of a frequency characteristic. FIG. 3 is an explanatory diagram in plan view of the acoustic generator 101 according to the comparative example, and shows a state in which the resin layer 40 is seen through as in FIG. 1A. In the graphs shown in FIGS. 2A and 2B, the horizontal axis indicates the frequency and the vertical axis indicates the sound pressure.
　比較例に係る音響発生器１０１は、図３に示すように、枠の内側の形状が矩形である枠体１１０の内側に振動体１２０が設けられており、振動体１２０を平面視したときの形状は矩形である。よって、振動体１２０を平面視したときの形状が有する２つの対角線Ｌ１０，Ｌ２０の長さは等しい。また、振動体１２０を平面視したときの形状は、４回対称の中心を有する四角形となっている。さらに、振動体１２０を平面視したときの形状は、線対称の対称軸を２本有している。このように、振動体１２０を平面視したときの形状は、対称性が非常に高い構造となっている。 As shown in FIG. 3, the acoustic generator 101 according to the comparative example is provided with a vibrating body 120 inside a frame 110 having a rectangular shape inside the frame, and when the vibrating body 120 is viewed in plan view. The shape is rectangular. Therefore, the lengths of the two diagonals L10 and L20 of the shape when the vibrating body 120 is viewed in plan are equal. Further, the shape of the vibrating body 120 when viewed from above is a quadrangle having a 4-fold symmetrical center. Furthermore, the shape when the vibrating body 120 is viewed in plan has two symmetrical axes of line symmetry. Thus, the shape of the vibrating body 120 when viewed in plan is a structure with very high symmetry.
　図２Ａおよび図２Ｂを比較すれば明らかなように、本実施形態に係る音響発生器１００は、音圧の周波数特性におけるピークやディップが小さくなっており、音圧の変動が低減されていることがわかる。 As is clear from a comparison between FIG. 2A and FIG. 2B, the sound generator 100 according to the present embodiment has a reduced peak or dip in the frequency characteristic of sound pressure, and fluctuations in sound pressure are reduced. I understand.
　次に、本実施形態の音響発生器１００の製造方法の一例について説明する。最初に、圧電振動素子３０を準備する。まず、圧電材料の粉末にバインダー、分散剤、可塑材、溶剤を混練し、スラリーを作製する。圧電材料としては、鉛系、非鉛系のうちいずれでも使用することができる。 Next, an example of a method for manufacturing the acoustic generator 100 of the present embodiment will be described. First, the piezoelectric vibration element 30 is prepared. First, a binder, a dispersant, a plasticizer, and a solvent are kneaded with the piezoelectric material powder to prepare a slurry. As the piezoelectric material, any of lead-based and non-lead-based materials can be used.
　次に、スラリーをシート状に成形してグリーンシートを作製する。そして、このグリーンシートに導体ペーストを印刷して、内部電極となる導体パターンを形成し、この電極パターンが形成されたグリーンシートを３枚積層し、その上には極パターンが印刷されていないグリーンシートを積層して、積層成形体を作製する。そして、積層成形体を脱脂、焼成し、所定寸法にカットすることによって積層体３３を得る。 Next, the slurry is formed into a sheet to produce a green sheet. Then, a conductor paste is printed on this green sheet to form a conductor pattern to be an internal electrode, three green sheets on which this electrode pattern is formed are stacked, and a green pattern on which no polar pattern is printed Sheets are laminated to produce a laminated molded body. And the laminated body 33 is obtained by degreasing and baking the laminated molded body and cutting it into predetermined dimensions.
　次に、必要に応じて積層体３３の外周部を加工し、積層体３３の積層方向の両主面に表面電極層３４、３５を形成するための導体ペーストを印刷し、引き続き、積層体３３の長手方向（Ｙ軸方向）の両端面に第１～第３の外部電極を形成するための導体ペーストを印刷し、所定の温度で電極の焼付けを行う。このようにして、図１Ａ及び図１Ｂに示す圧電振動素子３０を得ることができる。 Next, if necessary, the outer peripheral portion of the multilayer body 33 is processed, and a conductive paste for forming the surface electrode layers 34 and 35 is printed on both main surfaces in the stacking direction of the multilayer body 33. A conductor paste for forming the first to third external electrodes is printed on both end faces in the longitudinal direction (Y-axis direction) of the electrode, and the electrodes are baked at a predetermined temperature. In this way, the piezoelectric vibration element 30 shown in FIGS. 1A and 1B can be obtained.
　次に、圧電振動素子３０に圧電性を付与するために、第１～第３の外部電極を通じて直流電圧を印加して、圧電振動素子３０の圧電体層３１の分極を行う。かかる分極は、図１Ｂに矢印で示す方向となるように、ＤＣ電圧を印加して行う。 Next, in order to impart piezoelectricity to the piezoelectric vibration element 30, a DC voltage is applied through the first to third external electrodes to polarize the piezoelectric layer 31 of the piezoelectric vibration element 30. Such polarization is performed by applying a DC voltage so as to be in the direction indicated by the arrow in FIG. 1B.
　次に、フィルム２５を準備し、このフィルム２５の外周部を枠部材１１、１２間に挟み、フィルム２５に張力をかけた状態で固定する。この後、フィルム２５に接着剤層２６となる接着剤を塗布して、そのフィルム２５上に圧電振動素子３０の表面電極３４側を押し当て、この後、接着剤を加熱や紫外線を照射することによって硬化させる。そして、硬化前の樹脂を枠部材１１の内側に流し込み、樹脂を硬化させることによって、樹脂層４０を形成する。このようにして、本実施形態の音響発生器１００を作製することができる。 Next, the film 25 is prepared, the outer peripheral portion of the film 25 is sandwiched between the frame members 11 and 12, and the film 25 is fixed in a tensioned state. Thereafter, an adhesive to be the adhesive layer 26 is applied to the film 25, the surface electrode 34 side of the piezoelectric vibration element 30 is pressed onto the film 25, and then the adhesive is heated or irradiated with ultraviolet rays. To cure. Then, the resin layer 40 is formed by pouring the uncured resin inside the frame member 11 and curing the resin. In this way, the sound generator 100 of the present embodiment can be manufactured.
（第２の実施形態）
　次に、第２の実施形態に係る音響発生装置７０の構成について説明する。図４は、上述した第１の実施形態の音響発生器１００を用いて構成した音響発生装置７０の構成の一例を示す図である。なお、図４においては、説明に必要となる構成要素のみを示しており、音響発生器１００の詳細な構成や一般的な構成要素についての記載を省略している。 (Second Embodiment)
Next, the structure of the sound generator 70 according to the second embodiment will be described. FIG. 4 is a diagram illustrating an example of the configuration of the sound generation device 70 configured using the sound generator 100 of the first embodiment described above. In FIG. 4, only the components necessary for the description are shown, and the detailed configuration and general components of the sound generator 100 are omitted.
　本実施形態の音響発生装置７０は、いわゆるスピーカーのような発音装置であり、図４に示すように、たとえば、筐体７１と、筐体７１に取り付けられた音響発生器１００とを備える。筐体７１は、直方体の箱状の形状を有しており、１つの表面に開口７１ａを有している。このような筐体７１は、例えば、プラスチック、金属、木材などの既知の材料を用いて形成することができる。また、筐体７１の形状は、直方体の箱状に限定されるものではなく、例えば、円筒状や錐台状など、種々の形状とすることができる。 The sound generator 70 of the present embodiment is a so-called speaker-like sounding device, and includes, for example, a housing 71 and a sound generator 100 attached to the housing 71 as shown in FIG. The casing 71 has a rectangular parallelepiped box shape, and has an opening 71a on one surface. Such a casing 71 can be formed using a known material such as plastic, metal, or wood. Moreover, the shape of the housing | casing 71 is not limited to a rectangular parallelepiped box shape, For example, it can be set as various shapes, such as cylindrical shape and frustum shape.
　そして、筐体７１の開口７１ａに音響発生器１００が取り付けられている。音響発生器１００は、前述した第１形態の音響発生器であり、音響発生器１００についての説明は省略する。このような構成を有する音響発生装置７０は、音質が高い音響を発生させる音響発生器１００を用いて音響を発生させるので、音質が高い音響を発生させることができる。また、音響発生装置７０は、音響発生器１００から発生する音を筐体７１の内部で共鳴させることができるので、例えば低周波数帯域における音圧を高めることができる。なお、音響発生器１００が取り付けられる場所は自由に設定することができる。また、音響発生器１００が他の物を介して筐体７１に取り付けられるようにしても構わない。 The sound generator 100 is attached to the opening 71a of the casing 71. The sound generator 100 is the sound generator of the first form described above, and a description of the sound generator 100 is omitted. Since the sound generator 70 having such a configuration generates sound using the sound generator 100 that generates sound with high sound quality, it is possible to generate sound with high sound quality. Moreover, since the sound generator 70 can resonate the sound generated from the sound generator 100 inside the casing 71, for example, the sound pressure in a low frequency band can be increased. In addition, the place where the sound generator 100 is attached can be set freely. Further, the sound generator 100 may be attached to the housing 71 via another object.
（第３の実施形態）
　次に、第３の実施形態に係る電子機器の構成について説明する。図５は、前述した第１の実施形態の音響発生器１００を用いて構成した電子機器２の構成の一例を示す図である。なお、図５においては、説明に必要となる構成要素のみを示しており、音響発生器１００の詳細な構成や一般的な構成要素についての記載を省略している。電子機器２は、筐体２００と、筐体２００に設けられた音響発生器１００と、音響発生器１００に接続された電子回路とを備えている。 (Third embodiment)
Next, the configuration of the electronic device according to the third embodiment will be described. FIG. 5 is a diagram illustrating an example of the configuration of the electronic device 2 configured using the acoustic generator 100 of the first embodiment described above. In FIG. 5, only the components necessary for the description are shown, and the detailed configuration and general components of the sound generator 100 are omitted. The electronic device 2 includes a housing 200, a sound generator 100 provided in the housing 200, and an electronic circuit connected to the sound generator 100.
　詳細には、電子機器２は、図５に示すように、制御回路２１と、信号処理回路２２と、通信回路２３とを含む電子回路と、アンテナ２４と、これらを収納する筐体２００とを備えている。なお、電子機器２が備える他の電子部材（たとえば、ディスプレイ、マイクなどのデバイスや回路）については記載を省略した。 Specifically, as shown in FIG. 5, the electronic device 2 includes an electronic circuit including a control circuit 21, a signal processing circuit 22, and a communication circuit 23, an antenna 24, and a housing 200 that stores these. I have. In addition, description was abbreviate | omitted about other electronic members (for example, devices and circuits, such as a display and a microphone) with which the electronic device 2 is provided.
　通信回路２３は、アンテナから入力された信号を受信して信号処理回路２２へ出力する。信号処理回路２２は、通信回路２３から入力された信号を処理して音声信号Ｓを生成し、音響発生器１００へ出力する。音響発生器１００は、音声信号Ｓに基づいて音響を発生させる。制御回路２１は、信号処理回路２２および通信回路２３を含む電子機器２全体を制御する。 The communication circuit 23 receives a signal input from the antenna and outputs it to the signal processing circuit 22. The signal processing circuit 22 processes the signal input from the communication circuit 23 to generate an audio signal S and outputs it to the sound generator 100. The sound generator 100 generates sound based on the sound signal S. The control circuit 21 controls the entire electronic device 2 including the signal processing circuit 22 and the communication circuit 23.
　このような構成を有する電子機器２は、音圧の周波数特性における音圧の変動が小さい高音質な音響を発生させることが可能な音響発生器１００を有していることから、高音質な音響を発生させることができる。 Since the electronic device 2 having such a configuration includes the sound generator 100 capable of generating high-quality sound with small fluctuations in sound pressure in the frequency characteristics of sound pressure, the high-quality sound can be obtained. Can be generated.
　なお、図５においては、電子機器２の筐体２００に音響発生器１００が直接取り付けられた例を示したが、これに限定されるものではない。例えば、図４に示したような、音響発生器１００が筐体７１に取り付けられた音響発生装置７０が、電子機器２の筐体２００に取り付けられるような構成としても構わない。 In addition, in FIG. 5, although the example in which the sound generator 100 was directly attached to the housing | casing 200 of the electronic device 2 was shown, it is not limited to this. For example, as shown in FIG. 4, the sound generation device 70 in which the sound generator 100 is attached to the housing 71 may be configured to be attached to the housing 200 of the electronic device 2.
　また、このような音響発生器１００が搭載される電子機器２は、携帯電話機，タブレット端末，テレビ，オーディオ機器など、音響を発生させる電子機器として従来知られたものに限定されるものではない。音響発生器１００が搭載される電子機器２は、例えば、冷蔵庫、電子レンジ、掃除機、洗濯機などのような電気製品であっても構わない。 Further, the electronic device 2 on which such a sound generator 100 is mounted is not limited to those conventionally known as electronic devices that generate sound, such as a mobile phone, a tablet terminal, a television, and an audio device. The electronic device 2 on which the sound generator 100 is mounted may be an electrical product such as a refrigerator, a microwave oven, a vacuum cleaner, a washing machine, and the like.
（第４の実施形態）
　次に、第４の実施形態に係る音響発生器１０２の構成について、図６を用いて説明する。図６は、第４の実施形態に係る音響発生器１０２を振動体２０の厚み方向から平面視した説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、本実施形態においては、前述した第１の実施形態の音響発生機１００と異なる点のみについて説明し、同様の構成要素には同じ参照符号を付して、重複する説明を省略する。 (Fourth embodiment)
Next, the structure of the sound generator 102 according to the fourth embodiment will be described with reference to FIG. FIG. 6 is an explanatory view of the acoustic generator 102 according to the fourth embodiment viewed in plan from the thickness direction of the vibrating body 20, and shows a state where the resin layer 40 is seen through, as in FIG. 1A. In the present embodiment, only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
　本実施形態の音響発生器１０２では、振動体２０を平面視したときの形状（枠体１０の内側の形状と同じ形状）は、正五角形ではない五角形である。詳細には、振動体２０を平面視したときの形状は、矩形の角の１つを切り落として五角形とした形状である。また、振動体２０を平面視したときの形状は、５本の対角線Ｌ１１～Ｌ１５を有しており、５本の対角線の長さは全て異なっている。また、振動体２０を平面視したときの形状は、５回対称の中心を持たない五角形である。また、振動体２０を平面視したときの形状は、線対称の対称軸を持たない形状である。なお、このような振動体２０を平面視したときの形状は、図６に示すように、枠体１０の形状を、矩形状の枠の内側の１つの角に三角形状に内方へ張り出した領域１３を形成した形状とすることによって実現している。 In the acoustic generator 102 of the present embodiment, the shape when the vibrating body 20 is viewed in plan (the same shape as the shape inside the frame body 10) is a pentagon that is not a regular pentagon. Specifically, the shape of the vibrating body 20 when viewed in plan is a shape in which one of rectangular corners is cut off to form a pentagon. Further, the shape of the vibrating body 20 when viewed in plan has five diagonal lines L11 to L15, and the lengths of the five diagonal lines are all different. Further, the shape of the vibrating body 20 when viewed in plan is a pentagon having no 5-fold symmetry center. Further, the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry. In addition, as shown in FIG. 6, the shape of the vibrating body 20 in plan view is such that the shape of the frame body 10 is projected inward in a triangular shape at one corner inside the rectangular frame. This is realized by forming the region 13 into a shape.
　このように、本実施形態の音響発生器１０２は、振動体２０を平面視したときの形状を、対称性の低いものとしたことにより、振動体２０の共振モードの縮体を解くことができるので、周波数による音圧の変動が低減された高音質な音響を発生させることができる。 As described above, the acoustic generator 102 according to the present embodiment can solve the contraction of the resonance mode of the vibrating body 20 by making the shape of the vibrating body 20 when viewed from above low in symmetry. Therefore, it is possible to generate high-quality sound in which fluctuations in sound pressure due to frequency are reduced.
（第５の実施形態）
　次に、第５の実施形態に係る音響発生器１０３の構成について説明する。図７Ａは、第５の実施形態に係る音響発生器１０３を振動体２０の主面に垂直な方向（振動体２０の厚み方向）から平面視した説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、本実施形態においては、前述した第１の実施形態の音響発生機１００と異なる点のみについて説明し、同様の構成要素には同じ参照符号を付して、重複する説明を省略する。 (Fifth embodiment)
Next, the configuration of the sound generator 103 according to the fifth embodiment will be described. FIG. 7A is an explanatory diagram of the acoustic generator 103 according to the fifth embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). As in FIG. The state seen through the layer 40 is shown. In the present embodiment, only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
　本実施形態に係る音響発生器１０３は、振動体２０を平面視したときの形状が、２本の対角線Ｌ３１，Ｌ３２を有する形状であり、２本の対角線Ｌ３１，Ｌ３２の長さが互いに異なっている。また、振動体２０を平面視したときの形状は、４回対称の中心を持たない四角形となっている。また、振動体２０を平面視したときの形状は、線対称の対称軸を持たない形状である。このような構成を有する本例の音響発生器１０３は、振動体２０を平面視したときの形状の対称性が低いので、前述した第１の実施形態の音響発生器１００と同様に、音圧の周波数特性における音圧の変動が低減された高音質の音響を発生させることができる。 In the acoustic generator 103 according to the present embodiment, the shape when the vibrating body 20 is viewed in plan is a shape having two diagonal lines L31 and L32, and the lengths of the two diagonal lines L31 and L32 are different from each other. Yes. Further, the shape of the vibrating body 20 when viewed in plan is a quadrangle that does not have a 4-fold symmetrical center. Further, the shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry. Since the acoustic generator 103 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
（第６の実施形態）
　次に、第６の実施形態に係る音響発生器１０４の構成について説明する。図７Ｂは、第６の実施形態に係る音響発生器１０４を振動体２０の主面に垂直な方向（振動体２０の厚み方向）から平面視した説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、本実施形態においては、前述した第１の実施形態の音響発生機１００と異なる点のみについて説明し、同様の構成要素には同じ参照符号を付して、重複する説明を省略する。 (Sixth embodiment)
Next, the configuration of the sound generator 104 according to the sixth embodiment will be described. FIG. 7B is an explanatory view in plan view of the acoustic generator 104 according to the sixth embodiment from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). Similarly to FIG. The state seen through the layer 40 is shown. In the present embodiment, only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
　本実施形態に係る音響発生器１０４は、図７Ｂに示すように、振動体２０を平面視したときの形状が菱形となっており、２つの対角線Ｌ４１，Ｌ４２の長さが互いに異なっている。また、振動体２０を平面視したときの形状は、２回対称の中心および線対称の対称軸を有しているものの、４回対称の対称軸を有さない四角形である。このような構成を有する本例の音響発生器１０３は、振動体２０を平面視したときの形状の対称性が、ある程度は低いので、前述した第１の実施形態の音響発生器より程度は低いものの、音圧の周波数特性における音圧の変動が低減された高音質の音響を発生させることができる。 7B, the acoustic generator 104 according to the present embodiment has a rhombus shape when the vibrating body 20 is viewed in plan, and the lengths of the two diagonal lines L41 and L42 are different from each other. Further, the shape of the vibrating body 20 when viewed in plan is a quadrangle that has a center of two-fold symmetry and a line-symmetric symmetry axis but does not have a four-fold symmetry axis. The acoustic generator 103 of this example having such a configuration has a lower degree of symmetry of the shape when the vibrating body 20 is viewed in plan, and thus is lower than the acoustic generator of the first embodiment described above. However, it is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics of sound pressure are reduced.
（第７の実施形態）
　次に、第７の実施形態に係る音響発生器１０５の構成について説明する。図８Ａは、第７の実施形態に係る音響発生器１０５を振動体２０の主面に垂直な方向（振動体２０の厚み方向）から平面視した説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、本実施形態においては、前述した第１の実施形態の音響発生機１００と異なる点のみについて説明し、同様の構成要素には同じ参照符号を付して、重複する説明を省略する。 (Seventh embodiment)
Next, the configuration of the sound generator 105 according to the seventh embodiment will be described. FIG. 8A is an explanatory view of the acoustic generator 105 according to the seventh embodiment viewed in plan from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). Similarly to FIG. The state seen through the layer 40 is shown. In the present embodiment, only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
　本実施形態に係る音響発生器１０５は、図８Ａに示すように、振動体２０を平面視したときの形状が、９つの対角線Ｌ５１～Ｌ５９を有しており、９つの対角線Ｌ５１～Ｌ５９のうち少なくとも２つの対角線の長さが互いに異なっている。また、振動体２０を平面視したときの形状は、６回対称の中心を持たない六角形となっている。また、振動体２０を平面視したときの形状は、線対称の対称軸持たない形状である。このような構成を有する本例の音響発生器１０５は、振動体２０を平面視したときの形状の対称性が低いので、前述した第１の実施形態の音響発生器１００と同様に、音圧の周波数特性における音圧の変動が低減された高音質の音響を発生させることができる。 As shown in FIG. 8A, the acoustic generator 105 according to the present embodiment has nine diagonal lines L51 to L59 when the vibrating body 20 is viewed in plan, and the nine diagonal lines L51 to L59 are among the nine diagonal lines L51 to L59. At least two diagonals have different lengths. Further, the shape of the vibrating body 20 when viewed in plan is a hexagon that does not have a 6-fold symmetry center. The shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry. Since the acoustic generator 105 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
（第８の実施形態）
　次に、第８の実施形態に係る音響発生器１０６の構成について説明する。図８Ｂは、第８の実施形態に係る音響発生器１０６を振動体２０の主面に垂直な方向（振動体２０の厚み方向）から平面視した説明図であり、図１Ａと同様に、樹脂層４０を透視した状態を示している。なお、本実施形態においては、前述した第１の実施形態の音響発生機１００と異なる点のみについて説明し、同様の構成要素には同じ参照符号を付して、重複する説明を省略する。 (Eighth embodiment)
Next, the configuration of the sound generator 106 according to the eighth embodiment will be described. FIG. 8B is an explanatory view in plan view of the acoustic generator 106 according to the eighth embodiment from a direction perpendicular to the main surface of the vibrating body 20 (thickness direction of the vibrating body 20). Similarly to FIG. 1A, FIG. The state seen through the layer 40 is shown. In the present embodiment, only differences from the sound generator 100 of the first embodiment described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.
　本実施形態に係る音響発生器１０６は、図８Ｂに示すように、振動体２０を平面視したときの形状が、９つの対角線Ｌ６１～Ｌ６９を有しており、９つの対角線Ｌ６１～Ｌ６９のうち、少なくとも２つの対角線の長さが互いに異なっている。また、振動体２０を平面視したときの形状は、６回対称の中心を持たない六角形となっている。また、振動体２０を平面視したときの形状は、線対称の対称軸持たない形状である。このような構成を有する本例の音響発生器１０６は、振動体２０を平面視したときの形状の対称性が低いので、前述した第１の実施形態の音響発生器１００と同様に、音圧の周波数特性における音圧の変動が低減された高音質の音響を発生させることができる。 As shown in FIG. 8B, the acoustic generator 106 according to the present embodiment has nine diagonal lines L61 to L69 when the vibrating body 20 is viewed in plan, and among the nine diagonal lines L61 to L69, The lengths of at least two diagonal lines are different from each other. Further, the shape of the vibrating body 20 when viewed in plan is a hexagon that does not have a 6-fold symmetry center. The shape of the vibrating body 20 when viewed in plan is a shape that does not have a line-symmetric axis of symmetry. Since the acoustic generator 106 of this example having such a configuration has low symmetry of the shape when the vibrating body 20 is viewed in plan, the sound pressure is the same as that of the acoustic generator 100 of the first embodiment described above. It is possible to generate high-quality sound in which fluctuations in sound pressure in the frequency characteristics are reduced.
（変形例）
　上述実施形態では、振動体２０を平面視したときの形状が、四角形，五角形，六角形の場合を示したが、これに限定されるものではなく、他の多角形であっても構わない。また、多角形の頂点が丸みを帯びたものや頂点の角が削られているものでも良く、厳密ならずとも、多角形とみなされる形状であればよい。また、振動体２０の辺の全体や一部が曲線であるものも含まれる。 (Modification)
In the above-described embodiment, the case where the vibration body 20 is viewed in plan is a quadrangle, pentagon, or hexagon. However, the shape is not limited to this, and may be another polygon. Further, the polygonal vertex may be rounded or the corner of the vertex may be cut off, and any shape that is regarded as a polygon may be used if not strictly. Moreover, the whole or part of the side of the vibrating body 20 is a curved line.
　なお、上述した実施形態では、圧電振動素子３０を、振動体２０上に２個配設したものを例示したが、１個または３個以上の圧電振動素子３０を配置しても構わない。また、圧電振動素子３０を平面視で矩形状としたが、例えば楕円形状など、他の形状であってもよい。 In the above-described embodiment, two piezoelectric vibration elements 30 are disposed on the vibrating body 20, but one or three or more piezoelectric vibration elements 30 may be disposed. In addition, although the piezoelectric vibration element 30 has a rectangular shape in plan view, it may have another shape such as an elliptical shape.
　また、圧電振動素子３０として、いわゆるバイモルフ型の積層型を例示したが、これに限られるものではない。例えば、バイモルフ型の圧電振動素子に代えて、面方向に伸縮振動する圧電振動素子の一方主面に金属等の板を貼り付けて構成したユニモルフ型の圧電振動素子を用いても、同様の効果を得ることができる。また、面方向に伸縮振動する圧電振動素子をフィルム２５の両面に設けるようにしても良く、フィルム２５の両面にユニモルフ型やバイモルフ型の圧電振動素子を設けるようにしても良い。 Further, as the piezoelectric vibration element 30, a so-called bimorph type laminated type is exemplified, but the piezoelectric vibration element 30 is not limited to this. For example, the same effect can be obtained by using a unimorph type piezoelectric vibration element in which a plate made of metal or the like is attached to one main surface of a piezoelectric vibration element that expands and contracts in a plane direction instead of a bimorph type piezoelectric vibration element. Can be obtained. In addition, piezoelectric vibration elements that stretch and vibrate in the plane direction may be provided on both surfaces of the film 25, or unimorph type or bimorph type piezoelectric vibration elements may be provided on both surfaces of the film 25.
　さらなる効果や変形例は、当業者によって容易に導き出すことができる。このため、本発明のより広範な態様は、以上のように表しかつ記述した特定の詳細および代表的な実施形態に限定されるものではない。したがって、添付の特許請求の範囲およびその均等物によって定義される総括的な発明の概念の精神または範囲から逸脱することなく、様々な変更が可能である。 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.
　２：電子機器
　１０：枠体
　２０，１２０：振動体
　３０：圧電振動素子
　７０：音響発生装置
　７１，２００：筐体
　１００～１０６：音響発生器
　Ｌ１，Ｌ２，Ｌ１０～Ｌ１５，Ｌ２０，Ｌ３１，Ｌ３２，ｌ４１，ｌ４２，Ｌ５１～Ｌ５９，Ｌ６１～Ｌ６９：対角線 2: Electronic equipment 10: Frame body 20, 120: Vibrating body 30: Piezoelectric vibration element 70: Sound generator 71, 200: Housing 100 to 106: Sound generator L1, L2, L10 to L15, L20, L31, L32 , L41, l42, L51 to L59, L61 to L69: diagonal lines

Claims (6)

  1. 　枠体と、
    　該枠体の内側に設けられた振動体と、
    　該振動体上に設けられた圧電振動素子と、
    を備え、
    　前記振動体を平面視したときの形状が、複数の対角線を有する形状であり、前記複数の対角線のうち、少なくとも２つの対角線の長さが互いに異なる
    　ことを特徴とする音響発生器。     A frame,
    A vibrating body provided inside the frame;
    A piezoelectric vibration element provided on the vibrating body;
    With
    The shape of the vibrating body in plan view is a shape having a plurality of diagonal lines, and at least two of the diagonal lines have different lengths from each other.
  2. 　前記振動体を平面視したときの形状を、ｎ回対称の中心を持たないｎ角形（ｎは４以上の整数）とした
    　ことを特徴とする請求項１に記載の音響発生器。     The acoustic generator according to claim 1, wherein a shape of the vibrating body in plan view is an n-gon (n is an integer of 4 or more) having no n-fold symmetry center.
  3. 　前記振動体を平面視したときの形状は、線対称の対称軸を持たない
    　ことを特徴とする請求項１または２に記載の音響発生器。     3. The acoustic generator according to claim 1, wherein a shape of the vibrating body in plan view does not have a line-symmetric axis of symmetry.
  4. 　前記振動体の表面の少なくとも一部が、被覆層により被覆されている
    　ことを特徴とする請求項１、２または３に記載の音響発生器。     The acoustic generator according to claim 1, 2 or 3, wherein at least a part of the surface of the vibrating body is covered with a coating layer.
  5. 　筐体と、
    　該筐体に設けられた請求項１～４のいずれか一つに記載の音響発生器と、
    　を少なくとも備えることを特徴とする音響発生装置。     A housing,
    The sound generator according to any one of claims 1 to 4 provided in the housing;
    A sound generator comprising:
  6. 　筐体と、
    　該筐体に設けられた請求項１～４のいずれか一つに記載の音響発生器と、
    　該音響発生器に接続された電子回路と、
    　を少なくとも備え、
    　前記音響発生器から音響を発生させる機能を有することを特徴とする電子機器。     A housing,
    The sound generator according to any one of claims 1 to 4 provided in the housing;
    An electronic circuit connected to the acoustic generator;
    Comprising at least
    An electronic apparatus having a function of generating sound from the sound generator.
PCT/JP2013/070352 2012-08-10 2013-07-26 Acoustic generator, sound generation device, and electronic device WO2014024705A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012-179068 2012-08-10
JP2012179068 2012-08-10

Publications (1)

Publication Number Publication Date
WO2014024705A1 true WO2014024705A1 (en) 2014-02-13

Family

ID=50067938

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/070352 WO2014024705A1 (en) 2012-08-10 2013-07-26 Acoustic generator, sound generation device, and electronic device

Country Status (1)

Country Link
WO (1) WO2014024705A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015154298A (en) * 2014-02-15 2015-08-24 京セラ株式会社 Acoustic generator, acoustic generating apparatus, and electronic apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012110018A (en) * 2010-06-25 2012-06-07 Kyocera Corp Acoustic generator

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012110018A (en) * 2010-06-25 2012-06-07 Kyocera Corp Acoustic generator

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015154298A (en) * 2014-02-15 2015-08-24 京セラ株式会社 Acoustic generator, acoustic generating apparatus, and electronic apparatus

Similar Documents

Publication Publication Date Title
JP5815833B2 (en) Sound generator and sound generator using the same
JP6047575B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
JP6367693B2 (en) Piezoelectric element, piezoelectric vibration device, acoustic generator, acoustic generator, and electronic device
US20150125009A1 (en) Acoustic generator, acoustic generation device, and electronic apparatus
WO2013099512A1 (en) Vibration device, sound generator, speaker system, and electronic device
US20140233768A1 (en) Acoustic generator, acoustic generation device, and electronic device
JP5676016B2 (en) Vibration device, sound generator, speaker system, electronic equipment
JP6192743B2 (en) Sound generator, sound generator, electronic equipment
WO2014050214A1 (en) Acoustic generator, acoustic generation device and electronic device
WO2014024551A1 (en) Acoustic generator, acoustic generation device, and electronic apparatus
JP6117945B2 (en) Sound generator, sound generator, electronic equipment
JP5677637B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
JP5969863B2 (en) Piezoelectric element, sound generator, sound generator, and electronic device
JP5878980B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
WO2014024705A1 (en) Acoustic generator, sound generation device, and electronic device
JP5726375B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
WO2016017475A1 (en) Piezoelectric element, acoustic generator, acoustic generation device, and electronic apparatus
WO2014103970A1 (en) Sound generator, sound generating apparatus, and electronic apparatus
JP2016184786A (en) Acoustic generation device and electronic apparatus including the same
JP5933392B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
JP5871753B2 (en) SOUND GENERATOR, SOUND GENERATOR, AND ELECTRONIC DEVICE
JP6208595B2 (en) Sound generator, sound generator, electronic equipment
JP2014039094A (en) Acoustic generator, acoustic generating device, and electric device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13827481

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13827481

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP