JP6274385B2 - Ultrasonic element and parametric speaker - Google Patents

Description

  The present invention relates to an ultrasonic element that generates an ultrasonic wave by applying an alternating voltage and a parametric speaker using the ultrasonic element.

  The ultrasonic sounding body is a piezoelectric vibrator in which a metal plate and a piezoelectric element are bonded together, and vibrates by applying an alternating voltage in the vicinity of the resonance frequency unique to the piezoelectric vibrator to the piezoelectric vibrator to generate ultrasonic waves. The resonance frequency of the ultrasonic sounding body is an ultrasonic band (exceeding 20 kHz). In addition, by attaching a conical cylinder-shaped (including parabolic or funnel-shaped) resonator made of aluminum or an aluminum alloy to the piezoelectric vibrator, sound pressure can be increased and forward directivity can be provided. Can do.

  The ultrasonic sounding body is bonded with a silicon adhesive or the like at a node that does not move in the bending vibration of the piezoelectric vibrator, and is fixed so as not to prevent vibration as much as possible. Note that the ultrasonic sounding body has the same structure as the ultrasonic sensor, the ultrasonic sensor transmits and receives ultrasonic waves, and the ultrasonic sounding body only transmits ultrasonic waves.

  A parametric speaker is composed of a plurality of ultrasonic sounding elements arranged side by side, and the parametric speaker switches from ultrasonic waves to audible sound when the ultrasonic waves generated by the ultrasonic sounding elements reach in excess of the sound pressure that overlaps in the air. Demodulated and can be heard. Further, since only the central portion where the ultrasonic waves overlap becomes an audible sound, the speaker has a sharp directivity (see Patent Documents 1-3).

JP 2007-88886 A Japanese Patent Laid-Open No. 2001-258098 Utility Model Registration No. 3039055

  In the ultrasonic sensor described in Patent Documents 1 to 3, terminals 621 and 622 of the ultrasonic sensor 600 are provided outside the ring-shaped protrusion 612 that supports the piezoelectric element 616 as shown in FIG. The terminals 621 and 622 and the piezoelectric vibrator 650 are connected by lead wires 631 and 632 at a position above the terminal block 610.

  However, as shown in FIG. 9, when the positions of the terminals 621 and 622 are outside the diameter of the ultrasonic sounding body 650, it is necessary to increase the size of the terminal block 610 as well, and the ultrasonic sensor 600 becomes large. According to the configuration of the ultrasonic element 700 shown in FIG. 10, it can be seen that it is preferable to provide the terminals 621 and 622 between the outer periphery of the ring-shaped protrusion 612 and the outer periphery of the ultrasonic sounding body 650. There is a limit.

  As shown in FIG. 11, in the case of an ultrasonic wave generating element 700 in which a φ9 mm metal plate and a φ8 mm piezoelectric element are bonded together, a vibration node occurs at a position of φ6 mm. The ring-shaped protrusion 612 (thickness 0.5 mm) has an inner diameter φ5.75 mm and an outer diameter φ6.25 mm. In this case, the distance between the outer periphery of the ring-shaped protrusion 612 and the outer periphery of the ultrasonic sounding body 650 is 1.375 mm. After mounting on a substrate or the like, the ultrasonic element 700 is supported by the terminal 621. However, in order to withstand the vibration transmitted from the ultrasonic sound generator 650 to the terminal 621 through the terminal block 610, the terminals 621 and 622 should be somewhat thick. The thickness is preferably φ0.5 mm or more. However, the 1.375 mm width is too narrow to provide sufficient terminals 621. Further, even if it is provided, there is a concern that the terminal block 610 may be damaged.

  Thus, if the space between the outer periphery of the ring-shaped protrusion 612 and the outer periphery of the ultrasonic sounding body 650 is increased, the ultrasonic sounding body 650 is enlarged, and the ultrasonic element 600 cannot be reduced in size. In order to reduce the size of the ultrasonic sounding body 650, it is necessary to further narrow the space between the ring-shaped protrusion 612 and the ultrasonic sounding body 650, making it more difficult to provide the terminals 621 and 622.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ultrasonic element that can be easily provided with a terminal and can be reduced in size by reducing the outer diameter, and a parametric speaker using the ultrasonic element. .

(1) In order to achieve the above object, the ultrasonic element of the present invention comprises:
A terminal block having a pair of notches formed at the periphery of the disk-shaped bottom, and a ring-shaped protrusion provided on the bottom, and the disk-shaped at a position closer to the central axis than the outer diameter of the protrusion A pair of terminals inserted into the bottom of the pair, a pair of lead wires provided through the pair of notches, and supported by the ring-shaped protrusion, and connected to the pair of terminals by the pair of lead wires The ultrasonic sounding body is characterized in that the ultrasonic sounding body generates an ultrasonic wave when a voltage is applied from the pair of terminals.

  As described above, since the terminal is provided on the center axis side from the outer diameter of the protrusion, and the lead wire is connected to the terminal through the notch, the outer diameter of the terminal block is reduced to be equal to or smaller than the outer diameter of the ultrasonic element. The parametric speaker can be reduced in size. In addition, the process of providing the terminals is facilitated and easy to manufacture, and the terminal block is stable and difficult to break.

  (2) Moreover, the ultrasonic element of the present invention is characterized in that an outer diameter of the terminal block is equal to or smaller than an outer diameter of the ultrasonic sounding body. Thereby, an ultrasonic element can be produced according to the size of the ultrasonic sounding body, and the ultrasonic element can be made small. As a result, the parametric speaker can be reduced in size.

  (3) Further, in the ultrasonic element of the present invention, the terminal block has an installation part formed on the opposite side of the ring-shaped protrusion, and the installation part is placed on the substrate when the ultrasonic wave is installed on the substrate. The sound generation side surface of the sonic sound generator is supported parallel to the surface of the substrate at a constant height. Thereby, the sounding side surface of the ultrasonic sounding body on the substrate can be maintained at a constant height and parallel to the substrate. As a result, the phase of the ultrasonic wave is synchronized, and the directivity can be improved without canceling the ultrasonic wave from each element.

  (4) Moreover, the parametric speaker of this invention is equipped with said ultrasonic element and the board | substrate with which two or more said ultrasonic elements are installed, and supplies a voltage to a pair of said terminal, It is characterized by the above-mentioned. Thereby, a miniaturized parametric speaker can be realized.

  (5) Further, the parametric speaker of the present invention is characterized by further comprising a protector that is integrally formed and provided on the substrate and protects the plurality of ultrasonic elements. Thereby, since an integral protector can be installed with respect to the whole ultrasonic element, the parametric speaker provided with the protector can be further miniaturized.

  According to the present invention, the outer diameter of the terminal block can be made smaller than the outer diameter of the ultrasonic element, and the parametric speaker can be miniaturized. In addition, the process of providing the terminal is facilitated and easy to manufacture, and the stability of the terminal block can be improved and the breakage thereof can be prevented.

It is a front view which shows the parametric speaker which concerns on this invention. (A), (b) It is sectional drawing and bottom view which respectively show the ultrasonic element which concerns on 1st Embodiment, (c) It is a bottom view of a terminal block. It is sectional drawing which shows an ultrasonic sounding body, respectively (a)-(c). (D) It is a bottom view which shows an ultrasonic sounding body. (A), (b) It is sectional drawing and bottom view which respectively show the ultrasonic element which concerns on 2nd Embodiment, (c) It is a bottom view of a terminal block. It is a figure which shows the ultrasonic element which a board | substrate supports the opening end of a protective device. It is a bottom view which shows a terminal block, respectively (a)-(e). It is a front view which shows the parametric speaker which provided the individual protective equipment. (A), (b) is a top view which shows the parametric speaker without a protector and with an integral protector, respectively. It is sectional drawing which shows the conventional ultrasonic element. It is sectional drawing which shows the conventional ultrasonic element. It is an expanded sectional view showing the conventional ultrasonic element.

  Next, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

[First Embodiment]
(Configuration of parametric speaker)
FIG. 1 is a front view showing a parametric speaker. The parametric speaker 10 generates an ultrasonic wave modulated with a strong sound pressure and causes an audible sound to appear due to nonlinear characteristics when the ultrasonic wave propagates through the air. In this way, it is possible to specify the direction and distance and give directivity to convey acoustic information.

  As shown in FIG. 1, the parametric speaker 10 includes a plurality of ultrasonic elements 100 provided on a substrate 50 and connected to a signal source P. The ultrasonic element 100 generates an ultrasonic wave based on the modulation signal. The substrate 50 fixes and supports the ultrasonic element 100. In addition, in FIG. 1, the external appearance structure is shown and the electrical configuration is omitted.

(Configuration of ultrasonic element)
2A and 2B are a cross-sectional view and a bottom view showing the ultrasonic element 100, respectively. FIG. 2C is a bottom view of the terminal block. The ultrasonic element 100 includes a terminal block 110, a pair of terminals 121 and 122, a pair of lead wires 131 and 132, and an ultrasonic sounding body 150.

  In the terminal block 110, a pair of notches 113 and 114 are formed on the periphery of the disc-shaped bottom portion 111, and a ring-shaped protrusion 112 is provided on the bottom portion 111. Terminal holes 115 and 116 for inserting terminals are provided on the side of the bottom 111 opposite to the protrusion 112. The outer diameter of the terminal block 110 is preferably equal to or smaller than the outer diameter of the ultrasonic sounding body 150. Thereby, the ultrasonic element 100 can be manufactured according to the size of the ultrasonic sounding body 150, and the ultrasonic element 100 can be made small. As a result, the parametric speaker 10 can be reduced in size.

  The pair of terminals 121 and 122 are inserted into the disk-shaped bottom 111 at a position closer to the central axis than the outer diameter of the protrusion 112. The pair of lead wires 131 and 132 are provided via a pair of notches and connected to the terminals 121 and 122. Thereby, the outer diameter of the terminal block 110 can be made small. In addition, the process of providing the terminals 121 and 122 is facilitated and easy to manufacture, and is not easily damaged. The silicon adhesive 140 is applied so as to cover the lead wires 131 and 132, and is prevented by the piezoelectric vibrator 153 from breaking and abnormal noise generated by the vibration of the lead wires 131 and 132.

(Configuration of ultrasonic sound generator)
3A to 3C are cross-sectional views showing the ultrasonic sounding body 150, respectively. FIG. 3D is a bottom view showing the ultrasonic sounding body 150. The ultrasonic sounding body 150 is supported by a ring-shaped protrusion 112 of the terminal block 110 and is connected to a pair of terminals 121 and 122 by a pair of lead wires 131 and 132. The ultrasonic sounding body 150 generates ultrasonic waves by applying a voltage via the pair of terminals 121 and 122.

  The ultrasonic sounding body 150 generates a modulated ultrasonic signal by applying a voltage. The ultrasonic sounding body 150 includes a diaphragm 151, a piezoelectric element 152, and a resonator 154. The diaphragm 151 has a piezoelectric element 152 bonded to one main surface. The diaphragm 151 is formed in a disk shape from a metal such as brass, SUS304, 42 alloy, or aluminum.

  The piezoelectric element 152 is formed in a plate shape, and expands and contracts when a voltage is applied in the thickness direction. The piezoelectric element 152 is installed by being bonded to one main surface of the vibration plate 151. In the piezoelectric element 152, the other main surface of the vibration plate 151 is a vibration surface, and ultrasonic waves can be generated through the vibration surface. Electrodes are formed on both main surfaces of the piezoelectric element 152, and the piezoelectric body of the main body is polarized in the thickness direction. The vibration plate 151 and the piezoelectric element 152 form a piezoelectric vibrator 153.

  The resonator 154 is formed in a conical cylinder shape, and is made of, for example, aluminum or an aluminum alloy. The conical cylinder shape includes a parabolic shape or a funnel shape. The resonator 154 is provided on the other main surface of the diaphragm 151 and resonates with the vibration of the diaphragm 151 to generate an ultrasonic wave.

  As shown in FIGS. 3B to 3D, the ultrasonic sounding body 150 has a vibration node S, and is supported by the ring-shaped protrusion 112 of the terminal block 110 at the position of the node S. . Thereby, the ultrasonic sounding body 150 is not inhibited from vibration. The ultrasonic sounding body 150 is provided so that the sound generation side surface 156 of the ultrasonic sounding body 150 on the substrate 50 is maintained at a constant height and parallel to the substrate. As a result, the phases of the ultrasonic waves are synchronized, and the directivity can be improved without canceling the ultrasonic waves from the respective ultrasonic elements.

(Configuration method of ultrasonic element)
First, the diameter of the terminal block 110 is made equal to or smaller than the diameter of the ultrasonic sounding body 150, and the terminals 121 and 122 are arranged inside the ring-shaped protrusion 112. In that case, the lead wire is connected to the terminal 121 on the back side of the terminal block 110 by soldering. Further, in order to prevent disconnection or abnormal noise generated by the vibration of the lead wires 131 and 132 by being caught by the piezoelectric vibrator 153, the lead wires 131 and 132 are fixed with silicon adhesive 140. The notches 213 and 214 on the side of the terminal block 210 are provided so that the lead wires 131 and 132 do not go outside the piezoelectric vibrator 153.

[Second Embodiment]
(Configuration of ultrasonic element having an installation part)
In the above embodiment, the lead wire 131 and the like are exposed between the back surface of the terminal block 110 and the substrate 50, but the installation portion 218 that supports the surface of the ultrasonic element at a certain height on the back surface of the terminal block. It may be provided. 4A and 4B are a cross-sectional view and a bottom view showing the ultrasonic element 200 provided with the installation portion 218, respectively. FIG. 4C is a bottom view of the terminal block 210. The configuration of the ultrasonic element 200 shown in FIGS. 4A and 4B is basically the same as that of the ultrasonic element 100, but the terminal block 210 protrudes on the opposite side of the ring-shaped protrusion 212. An installation portion 218 is formed. The installation unit 218 can support the sound generation side surface 156 of the ultrasonic sound generator 150 parallel to the surface of the substrate 50 at a certain height when the ultrasonic element 200 is installed on the substrate 50, and does not hinder wiring. It is formed in a horseshoe shape.

  As shown in FIG. 4C, the terminal block 210 has a pair of notches 213 and 214 formed on the periphery of the disk-shaped bottom portion 211, and a ring-shaped protrusion 212 provided on the bottom portion 211. . The ring-shaped protrusion 212 supports the ultrasonic sounding body 150. Terminal holes 215 and 216 for inserting terminals are provided on the side of the bottom 211 opposite to the protrusion 212.

(Pronunciation side)
In the use of a conventionally known ultrasonic sensor, since it is used alone, there is no major problem in use even if the height and the parallel surface of the sounding surface vary. However, in the parametric speaker 10 configured by arranging a plurality of ultrasonic sound generators 150, if the height of each ultrasonic sound generator 150 is different, the phases of the ultrasonic waves emitted from the ultrasonic sound generators 150 are shifted and cancel each other. Since each ultrasonic sound generator 150 does not become parallel and the directivity of the parametric speaker 10 varies when the direction of emitting ultrasonic waves varies, the ultrasonic sound generator 150 must be parallel with a constant height.

  On the other hand, in the present invention, the ultrasonic element 200 can be miniaturized and mounted with a constant height and in parallel. Although the diameter of the ultrasonic element 100 shown in FIG. 2 is small, the solder that connects the lead wires 131 and 132 and the terminals 121 and 122 and the silicon that fixes the lead wires 131 and 132 are fixed to the back surface of the terminal block 110. There is an adhesive 140. Therefore, it is not easy to mount the ultrasonic element 100 on a substrate or the like at a constant height and in parallel.

  For this, it is also conceivable that the cylindrical opening end of the protector is supported by the substrate and the sound generation surface of the ultrasonic sound generator 150 is mounted parallel to the substrate. FIG. 5 is a view showing the ultrasonic element 300 supported by the opening end 312 of the protector 302.

  However, when the protector 302 is used, the terminal block 110 needs to have a diameter that is slightly larger than the diameter of the ultrasonic sounding body 150 so that it does not come into contact with the ultrasonic sounding body 150. Furthermore, since the protective device 302 has a thickness, the diameter of the ultrasonic element 100 is increased. Therefore, the ultrasonic element 200 is provided with an installation portion 218 that is equal to or larger than the thickness of the lead wires 131 and 132, solder, and silicon adhesive 140.

(Installation parts of various shapes)
6A to 6E are bottom views showing the terminal blocks 210a to 210e, respectively. The terminal block 210a is provided with a bottom fan-shaped installation part 218a divided into three equal parts, and the terminal block 210b is provided with a bottom fan-shaped installation part 218b divided into four equal parts. The terminal block 210c is provided with a bottom H-shaped installation portion 218c so as to avoid terminal holes and notches. The terminal block 210d is provided with a bottom X-shaped installation portion 218d so as to avoid terminal holes and notches. The terminal block 210e is provided with an installation portion 218e having a shape that avoids the terminal hole and the notch in an elliptical shape. Thus, it is preferable that the installation part 218 has a shape that avoids the notches 213 and 214 and the terminal holes 215 and 216 with a sufficient margin.

  It is possible to mount the sound generating surface at a constant height and parallel by sandwiching a spacer or the like between the substrate 50 and the terminal block 110 or using the protector 302, but this increases the number of components. It is not preferable. When providing the installation part 218 in the terminal block 210, the installation part 218 and the bottom part 211 can be integrated by resin molding.

[Third Embodiment]
(Integral protective equipment)
FIG. 7 is a front view showing the parametric speaker 30 in which the ultrasonic element 300 provided with the protector 302 is arranged. Similar to the ultrasonic sensor, the single ultrasonic element 300 is protected by a protector 302.

  FIGS. 8A and 8B are plan views showing parametric speakers 40 and 45 with and without protective equipment, respectively. The parametric speaker 40 includes a substrate 50 on which a plurality of ultrasonic elements 100 are installed and supplies a voltage to a pair of terminals. The ultrasonic element 300 includes a protector 310 that is integrally provided on the substrate 50 and protects the plurality of ultrasonic elements 300. Thereby, since the integral protector 310 can be installed with respect to the whole ultrasonic element 300, the parametric speaker 40 can be further reduced in size. If the ultrasonic elements without the protector 302 are arranged as shown in FIG. 8A and are collectively protected as shown in FIG. 8B and protected by the protector 310 with integrated protection, the parametric speaker 30 can be reduced in size.

10, 30, 40, 45 Parametric speaker 50 Substrate 100 Ultrasonic element 110 Terminal block 111 Bottom 112 Protrusion 113, 114 Notch 115, 116 Terminal hole 121, 122 Terminal 131, 132 Lead wire 140 Silicon adhesive 150 Ultrasonic sound generation Body 151 Diaphragm 152 Piezoelectric element 153 Piezoelectric vibrator 154 Resonator 156 Sound generation side surface 200 Ultrasonic element 210 Terminal block 210a-210e Terminal block 211 Bottom 212 Projection 213, 214 Notch 215, 216 Terminal hole 218 Installation portion 218a- 218e Installation unit 300 Ultrasonic element 302 Single protective device 310 Multiple integrated protective device

Claims (4)

A parametric speaker comprising a plurality of ultrasonic elements and a substrate on which the ultrasonic elements are installed,
The ultrasonic element is
A terminal block in which a pair of notches are formed at the periphery of the disk-shaped bottom, and a ring-shaped protrusion is provided on the bottom;
A pair of terminals inserted into the disc-shaped bottom at a position closer to the central axis than the outer diameter of the protrusion,
A pair of lead wires provided through the pair of notches;
An ultrasonic sounding body supported by the ring-shaped protrusion and connected to the pair of terminals by the pair of lead wires,
The lead wire is covered with an adhesive and is fixed to at least the terminal block;
The substrate supplies a voltage to the pair of terminals,
The parametric speaker , wherein the ultrasonic sounding body generates ultrasonic waves when a voltage is applied from the pair of terminals. The parametric speaker according to claim 1, wherein an outer diameter of the terminal block is equal to or smaller than an outer diameter of the ultrasonic sounding body. The terminal block has an installation portion formed on the opposite side of the ring-shaped protrusion,
The said installation part supports the sound generation side surface of the said ultrasonic sounding body in parallel with a fixed height with respect to the surface of the said board | substrate when installed in a board | substrate. Parametric speaker . The parametric speaker according to any one of claims 1 to 3, further comprising a protector that is integrally formed and provided on the substrate and protects the plurality of ultrasonic elements.

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