JPH0749912Y2 - Piezoelectric electroacoustic transducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a structure of a piezoelectric electroacoustic transducer using a diaphragm having a piezoelectric material attached thereto.

(2) Prior Art In recent years, there is a receiver that is used as a transmitter / receiver of a telephone for a hearing aid user, and is provided with a coil for generating a magnetic flux of an audio signal. This coil is used for magnetically coupling with a pickup coil provided in the hearing aid to induce an audio signal.

It is well known that an acoustic transducer of electromagnetic type, electrodynamic type, piezoelectric type or the like has been conventionally used as a receiver of a telephone, but in a piezoelectric receiver, it is magnetically coupled with a hearing aid having a pickup coil. Therefore, it becomes necessary to leak the magnetic flux. In electromagnetic type and electrodynamic type receivers, a voice signal can be obtained by magnetically coupling to a hearing aid having a pickup coil, but in piezoelectric type receivers, there is no mechanism for generating magnetic flux leakage, so magnetic Could not bind.

FIG. 4 shows a cross-sectional view of an example of a conventional piezoelectric receiver [see Jpn. Kokoku Sho 59-34239]. FIG. 5 is a bottom view of the piezoelectric diaphragm, and FIG. 4 is a sectional view thereof. The front cover 6 adopts a caulking structure and is fixed.

Here, 1 is a vibrating substrate made of a metal material, 2 is a piezoelectric ceramic plate, 3 is electrodes provided on both surfaces of the piezoelectric ceramic plate 2, and an electrode 3-1 on the vibrating substrate 1 side and a side opposite to the vibrating substrate 1 are provided. Electrode 3-2. Reference numeral 4 is an insulating layer provided on the surface of the vibrating substrate 1 on the side of the piezoelectric ceramic plate 2, and 5 is a conductive layer provided on the insulating layer 4 from the electrode 3-2 on the opposite side of the vibrating substrate 1. The electrode 3-1 on the vibration substrate 1 side is the vibration substrate 1
It is in continuity with. An insulating layer 4 is provided on at least a part of the surface of the vibration substrate 1 on the side where the piezoelectric ceramic plate 2 is attached, other than where the piezoelectric ceramic plate is attached, that is, about half in the illustrated case, and the vibration substrate 1 is formed thereon. The conductive layer 5 is arranged so as not to come into contact with, and a part of the conductive layer 5 is connected to the electrode 3-2 on the side opposite to the vibration substrate 1.

FIG. 6 shows a terminal board, in which two half conductive patterns 7-1 and 7-2 are provided on the terminal board 7, acoustic leak holes 9 are provided, and a damper material 10 is provided. .
One conductive pattern 7-1 of the terminal board 7 is electrically connected to the terminal 8-1, and the other conductive pattern 7-2 is electrically connected to the terminal 8-2.

Therefore, the conductive layer 5 is in contact with the conductive pattern 7-2 of the terminal board 7, and the portion 1-1 where the conductive layer 5 is not arranged on the same circumference of the vibration substrate 1 on which the conductive layer 5 is arranged is the terminal board 7. By stacking so as to contact the conductive pattern 7-1 of
It can be easily integrated, and the terminal 8-1 and the electrode 3-1 are electrically connected, and the terminal 8-2 and the electrode 3-2 are electrically connected. When an audio signal voltage is applied between the two terminals 8-1 and 8-2, the terminal 8-1 is electrically connected to the metal diaphragm 1 through the conductive pattern 7-1 and the terminal 8-2 is connected to the conductive pattern 7-. Two
Is conducted to the conductive layer 5 via the piezoelectric ceramic plate 2, and a voice signal current flows through the electrodes 3-1 and 3-2 on both sides of the piezoelectric ceramic plate 2, and the vibration substrate 1
Vibrates according to the voice signal current, and a voice output is obtained.

As described above, this piezoelectric receiver has a simple electrical connection with the external terminals of both electrodes of the piezoelectric ceramic plate, so that the assembly structure is simple and the manufacture is easy, and it is suitable for automated assembly.

However, in this structure, as described above, the mechanism for generating the leakage magnetic flux is necessary.

In order to solve this drawback, the inventor of the present application has filed Japanese Patent Application No. 2-30
No. 496 "Piezoelectric electroacoustic transducer" was proposed. However, in the structure according to this prior application, since the distance between the coil and the pickup coil of the hearing aid is large, the leakage magnetic flux generated from the coil cannot be efficiently transmitted to the pickup coil of the hearing aid.

(3) Purpose of the Invention The present invention solves the above-mentioned drawbacks of the prior art, has a mechanism for generating a leakage magnetic flux and efficiently magnetically coupling to a pickup coil of a hearing aid, and has a simple assembly structure and is easy to manufacture. Moreover, the present invention provides a piezoelectric electroacoustic transducer having a stable sensitivity frequency characteristic.

(4) Configuration and operation of the device To achieve this object, the piezoelectric electroacoustic transducer of the present invention is a piezoelectric electroacoustic transducer in which one electrode of a piezoelectric material having a pair of electrodes on both sides is attached to a metal vibration substrate. A vibrator and a terminal plate having two external terminals respectively connected to the pair of electrodes are provided, and the metal vibrating substrate has a concave portion formed in the central portion so that a peripheral portion thereof protrudes from the central portion. The piezoelectric material is attached to the concave portion, and an insulating layer is applied to at least a part of the surface of the metal vibration substrate other than the portion to which the piezoelectric material is attached, and the other electrode different from the one electrode. A conductive layer is applied from the electrodes to the insulating layer, the terminal plate is formed in a flat plate shape, and a first conductive pattern connected to one and the other of the two external terminals on one surface of the terminal plate. And the second conductive pattern The coil bobbin is attached to the one surface side of the terminal plate, and the coil bobbin is arranged so as to surround the recessed portion of the metal vibrating substrate. Both ends of the coil are attached to the peripheral portion of the metal vibrating substrate. A coil assembly is formed so as to be connected to the first conductor pattern and the second conductor pattern on the outer side through two terminals of the coil bobbin, respectively, and the piezoelectric vibrator and the coil bobbin are connected to the terminal plate. The first conductive pattern is contact-connected to one of the two terminals of the conductive layer and the coil bobbin by stacking and coupling the one surface side, and the second conductive pattern is the peripheral portion of the metal vibrating substrate and the one of the two terminals. The coil assembly is disposed so as to accommodate the coil assembly, the metal vibrating board, and the terminal plate, being contact-connected to the other of the two terminals of the coil bobbin. The front cover is integrally formed by a caulking structure using a peripheral portion of the front cover, and a leakage magnetic flux is generated by a signal applied from the coil to the external terminal.

An embodiment of the present invention will be described below.

FIG. 1 shows a sectional view of an embodiment of the present invention. The piezoelectric vibrating plate is the same as that shown in FIG. 5 of the conventional example, and similarly to the conventional example, the front cover 16 adopts a caulking structure and is fixed.

FIG. 2 shows the terminal board 17 of the embodiment, which is divided into two semi-circular areas divided by the diameter on the circular surface of the terminal board 17.
Two conductive patterns 17-1 and 17-2 are provided, an acoustic leak hole 9-1 is provided at the center, and a damper material 10-1 is provided on the inner wall thereof. One conductive pattern 17-1 of the terminal board 17 is electrically connected to the terminal 18-1 and
The two conductive patterns 17-2 are electrically connected to the terminal board 18-2.

FIG. 3 is a sectional view of the coil assembly 20 of the embodiment, in which the coil 22 is wound around the coil bobbin 21, and the lead wires (not shown) at both ends of the coil 22 are provided on the plane of the coil bobbin 21. 22-1 and 22-2 are respectively connected.

The coil electrodes 22-1 and 22-2 can be integrally formed by insert-molding a metal piece when the coil bobbin 21 is molded with a resin material, but the metal piece is provided on the plane of the coil bobbin 21 afterwards. The coil electrodes 22-1, 22-
The same can be obtained by forming 2.

The coil electrodes 22-1 and 22-2 are not limited to metal pieces, and may be made of a conductive substance such as a conductive adhesive or conductive rubber.

As shown in FIG. 1, these components are sequentially stacked, and a front cover 16 is used to form a caulked structure, which is integrated and fixed. At this time, one conductive pattern 17-2 of the terminal board 17 is
The coil assembly 20 is stacked so as to be in contact with the coil electrode 22-2 and the conductive layer 5. The other conductive pattern 17-1 of the terminal board 17 is in contact with the coil electrode 22-1 of the coil assembly 20 and the vibrating substrate 1 on which the conductive layer 5 is arranged.
On the same circumference, where the conductive layer 5 is not arranged 1-1
Stack so that it makes contact with.

By stacking in this way, they can be easily integrated, and the terminal 18-1 and the electrode 3-1 are electrically connected, and the terminal 18-2 and the electrode 3-2 are electrically connected.

Therefore, when an audio signal is applied between the two terminals 18-1 and 18-2, the audio signal flows through the piezoelectric ceramic plate 2 and the coil 22.

As a result, a leakage magnetic flux corresponding to the audio signal is generated in the coil 22, and the leakage magnetic flux is coupled to the coil 22 so that the leakage magnetic flux is generated.
Is efficiently guided to a pickup coil provided in a hearing aid (not shown) arranged close to the.

(5) Effects of the Invention As shown in the above embodiments, a concave portion is formed in the central portion of the diaphragm 1 so that the peripheral edge portion of the diaphragm 1 projects from the central portion, and the piezoelectric material 2 is formed in the concave portion. Because it is pasted,
The contact between the conductive patterns 17-1 and 17-2 on the terminal plate 17 and the electrodes is stable, and the shape and volume of the air chamber are stabilized. Therefore, there is an effect that the fundamental resonance frequency (f ₀₁ ) is stable.

Further, since the piezoelectric acoustic transducer according to the present invention has a simple electrical connection with the external terminals of both electrodes of the piezoelectric material, the assembly structure is simple and the manufacture is easy, and is suitable for assembly automation. In addition, since leakage magnetic flux is generated, there is an advantage that coupling to a hearing aid is easy and a sufficient hearing aid effect can be obtained.

Moreover, with respect to the structure according to the above-mentioned prior application, it is possible to more efficiently transfer the leakage magnetic flux generated from the coil to the pickup coil of the hearing aid by the appropriate structure in which the coil is arranged in the anterior chamber of the acoustic system. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing an example of the structure of a terminal plate used in the present invention, and FIG. 3 is a vertical section showing an example of the structure of a coil assembly used in the present invention. Floor plan,
FIG. 4 is a cross-sectional view showing a conventional example of a piezoelectric electroacoustic transducer which is the subject of the present invention, FIG. 5 is a bottom view showing an example of FIG. 4 and a structural example of a piezoelectric vibrator used in the present invention, Sixth
The drawing is a plan view showing a structural example of the terminal board used in the example of FIG. 1 ... Vibration substrate, 1-1 ... Portion where no conductive layer is arranged,
2 ... Piezoelectric ceramic plate, 3,3-1,3-2 ... Electrode, 4 ... Insulating layer, 5 ... Conductive layer, 6 ... Front cover, 7,27 ... Terminal plate, 7
-1,7-2,17-1,17-2 ... Conductive pattern, 8-1,8-2,18
-1,18-2 ... Terminal, 9,9-1 ... Acoustic leakage hole, 10,10-1 ...
Damper material, 20 ... Coil assembly, 21 ... Bobbin, 22 ... Coil,
22-1, 22-2 ... Coil electrodes.

Claims (1)

[Scope of utility model registration request] 1. A piezoelectric vibrator in which one electrode of a piezoelectric material having a pair of electrodes on both sides is attached to a metal vibrating substrate, and a terminal plate having two external terminals respectively connected to the pair of electrodes. The metal vibrating substrate is provided with a concave portion in the central portion so that the peripheral portion of the vibrating substrate protrudes from the central portion, and the piezoelectric material is attached to the concave portion. An insulating layer is provided on at least a part of the surface other than the portion where is attached, and a conductive layer is applied from the other electrode different from the one electrode to the insulating layer, and the terminal plate is formed in a flat plate shape. A first conductive pattern and a second conductive pattern, which are respectively connected to one and the other of the two external terminals, are adhered to one surface of the terminal plate, and the one surface of the terminal plate is further attached to the one surface side. Remove the concave portion of the metal vibrating substrate. A coil is wound around a coil bobbin arranged so that both ends of the coil are connected to the first conductor pattern and the second conductor pattern outside the peripheral portion of the metal vibrating substrate by connecting two terminals of the coil bobbin. A coil assembly is formed so as to be connected to each other via the piezoelectric vibrator and the coil bobbin, and the first conductive pattern is formed by stacking and coupling the piezoelectric vibrator and the coil bobbin on the one surface side of the terminal plate. The second conductive pattern is contact-connected to one of the two terminals, and the second conductive pattern is contact-connected to the peripheral portion of the metal vibrating substrate and the other of the two terminals of the coil bobbin, and the coil assembly includes the coil assembly and the metal. The vibrating substrate and the terminal plate are integrated by a caulking structure using a peripheral portion of the front cover arranged so as to accommodate the coil. The piezoelectric electroacoustic transducer, characterized in that the leakage magnetic flux due to the signal applied to et the external terminal is configured to generate.