JPH06125597A - Electric acoustic transducer - Google Patents

Abstract

PURPOSE:To reduce the production cost and to easily improve the production of a receiver. CONSTITUTION:The device is provided with a piezoelectric diaphragm 2 jointing a piezoelectric ceramic board 5 and a metallic sheet 6 face to face, resin case 3 housing it, and coil 4 wound around the resin case 3. Either of the piezoelectric ceramic board 5 or the metallic sheet 6 and one end 4a of the coil 4 are pulled outside of the resin case 3 through a 1st external connection terminal 12. Either of the piezoelectric ceramic board 5 and the metallic plate 6 and the other end 4b of the coil 4 are pulled outside of the resin case 3 through 2nd and 3rd external connection terminals 13 and 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electroacoustic transducer (hereinafter, referred to as
The present invention relates to a transducer incorporated in a piezoelectric receiver for a hearing-impaired person.

[0002]

2. Description of the Related Art Heretofore, as a piezoelectric receiver of this type, one generally constructed by incorporating a converter called a two-terminal type or a four-terminal type. Then, first, as shown in the equivalent circuit diagram of FIG. 3, a converter 20 called a two-terminal type is provided with a piezoelectric diaphragm 21 having required characteristics,
A resistor 22 connected in series with the piezoelectric vibration plate 21 and a resin case (not shown) that collectively stores these.
And a coil 23 which is connected in parallel with the piezoelectric vibrating plate 21 and the resistor 22. Also, although not shown,
The piezoelectric vibrating plate 21 here is configured by face-bonding a piezoelectric ceramic plate and a metal plate. The resistor 22 ensures the sound pressure-frequency characteristics required for the converter, and the coil 23 is provided to generate a leakage magnetic flux corresponding to the pickup coil in the hearing aid used by the hearing-impaired person. Is. Then, in this converter, one of the piezoelectric ceramic plate and the metal plate forming the piezoelectric vibrating plate 21 and the coil 2 is used.
One end of the coil 3 is connected to each other, and the other of the piezoelectric ceramic plate and the metal plate and the other end of the coil 23 are connected to each other. Each of these is connected to the external connection terminals 24 and 25. Through each, it is pulled out to the outside of the resin case.

A converter 30 called a four-terminal type is
As shown in the equivalent circuit diagram of FIG. 4, the piezoelectric vibrating plate 21 and the coil 23 similar to the above are provided, and each of these is provided separately and extends to the outside of the resin case (not shown). Four external connection terminals 31 to 34 pulled out
Are connected respectively. The resistor 22, which is also required in the converter 30, is mounted on a circuit board (not shown) for a receiver to which the converter 30 is attached, and then connected in series with the piezoelectric diaphragm 21. .

[0004]

By the way, in the two-terminal type converter 20 having the above-mentioned conventional structure,
The resistor 22 has to be housed in a resin case because of the necessity of configuring the terminal type, and the resin which has a narrow soldering connection using a lead wire or the like between the resistor 22 and the piezoelectric vibrating plate 21. Since it has to be carried out in the case, there has been a problem in that the assembly work requires a troublesome work, resulting in a large increase in manufacturing cost.

Further, in the four-terminal type converter 30,
Since it is necessary to separately connect as many as four external connection terminals 31 to 34 to each of the circuit patterns formed on the circuit board, the time and effort for soldering and the like at the time of attachment to the circuit board will increase, Handset productivity could not be improved.

The present invention was devised in view of such inconveniences, and an object thereof is to provide a converter capable of reducing the manufacturing cost and improving the productivity of the handset.

[0007]

In order to achieve such an object, a converter according to the present invention includes a piezoelectric vibrating plate in which a piezoelectric ceramic plate and a metal plate are face-bonded to each other, and a resin case for housing the same. And a coil wound around the resin case, and one of the piezoelectric ceramic plate and the metal plate and one end of the coil are drawn out of the resin case through a first external connection terminal commonly connected. On the other hand, the other of the piezoelectric ceramic plate and the metal plate and the other end of the coil are drawn out to the outside of the resin case through the respectively connected second and third external connection terminals.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an equivalent circuit diagram showing an electrical configuration of a converter according to this embodiment, and FIG. 2 is a sectional view showing a simplified actual configuration thereof. Reference numeral 1 in these figures denotes a converter. Shows.

As shown in FIGS. 1 and 2, the converter 1 has a piezoelectric vibrating plate 2 having required characteristics, a resin case 3 for housing the same, and a resin case 3 wound around the resin case 3. And a coil 4 for generating a leakage magnetic flux. The piezoelectric vibrating plate 2 is a piezoelectric ceramic plate 5 having electrodes (not shown) formed on both front and back surfaces.
And a metal plate 6 having an outer diameter larger than that of the metal plate 6 and the metal plate 6 facing each other concentrically, and the two are joined by a conductive adhesive (not shown) or the like to be integrated.

Further, the resin case 3 accommodates the piezoelectric vibrating plate 2 along the thickness direction thereof, and in the vibration node point of the piezoelectric vibrating plate 2, that is, in the spreading direction of the metal plate 6 constituting the vibrating plate. It is composed of an outer case 7 and an inner case 8 that sandwich the outer peripheral edge portion and hold the outer peripheral portion in a vibrating manner. A groove for winding the coil 4 is formed on the entire outer peripheral edge of the outer case 7 in the spreading direction, and a braking hole 9 is formed at a substantially central position in the spreading direction. The inner surface of the braking hole 9 is covered with the braking film 10. And
A sound emitting hole 11 is formed at a predetermined position of the inner case 8 facing the braking hole 9 via the piezoelectric vibrating plate 2.

Further, three external connection terminals 12 to 14 are attached to the outer case 7 constituting the resin case 3 in a state of being pulled out to the outside, and with respect to the first external connection terminal 12. , A metal plate 6 that constitutes the piezoelectric vibration plate 2
Is soldered and connected via the lead wire 15,
One end 4a of the coil 4 is directly soldered and connected. The second external connection terminal 13 among these is connected to the piezoelectric ceramic plate 5 constituting the piezoelectric vibration plate 2 by soldering via the lead wire 16, while it is connected to the third external connection terminal 14 by soldering. The other end 4b of the coil 4 is directly connected by soldering. At this time, of course, the first external connection terminal 12 and the piezoelectric ceramic plate 5 may be connected, and the second external connection terminal 13 and the metal plate 6 may be connected.

Therefore, one of the piezoelectric ceramic plate 5 and the metal plate 6 forming the piezoelectric vibrating plate 2 of the converter 1 and the one end 4a of the coil 4 are commonly connected.
Is pulled out to the outside of the resin case 3 through the external connection terminals 12 of the piezoelectric ceramic plate 5 and the metal plate 6.
The other of them and the other end 4b of the coil 4 are pulled out to the outside of the resin case 3 in different states through the second and third external connection terminals 13 and 14, respectively. Then, each of the external connection terminals 12 to 14 drawn out of the resin case 3 is on a circuit board (not shown) that constitutes a handset via the lead wire 17 or the like that is soldered to each of the external connection terminals 12 to 14. Connected to each of the circuit patterns. The converter 1 according to the present embodiment also uses the resistor 22 for ensuring the sound pressure-frequency characteristics, and the resistor 22 is mounted on the circuit board for the handset to which the converter 1 is attached. In addition, it is connected in series with the piezoelectric diaphragm 2.

[0014]

As described above, according to the converter of the present invention, one of the piezoelectric ceramic plate and the metal plate and only one end of the coil are commonly connected, and the piezoelectric ceramic plate and the metal plate are connected. Since the other end of the coil and the other end of the coil are left connected to each other, the number of external connection terminals drawn out from the resin case to three results in the conventional four.
Compared with the terminal type converter, it is possible to reduce the labor at the time of attachment to the circuit board and improve the productivity of the handset. Further, unlike the conventional two-terminal converter, it is not necessary to store the resistor in the resin case, so that the assembling work is simplified and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram showing an electrical configuration of a converter according to an embodiment.

FIG. 2 is a cross-sectional view showing a simplified substance structure.

FIG. 3 is an equivalent circuit diagram showing an electrical configuration of a two-terminal converter according to a conventional example.

FIG. 4 is an equivalent circuit diagram showing an electrical configuration of a 4-terminal converter according to a conventional example.

[Explanation of symbols]

 1 Transducer (electro-acoustic transducer) 2 Piezoelectric diaphragm 3 Resin case 4 Coil 4a One end 4b Other end 5 Piezoelectric ceramic plate 6 Metal plate 12 First external connection terminal 13 Second external connection terminal 14 Third external Connecting terminal

Claims (1)

[Claims] 1. A piezoelectric vibrating plate (2) formed by facing a piezoelectric ceramic plate (5) and a metal plate (6) to each other, a resin case (3) accommodating the piezoelectric vibrating plate (2), and a winding on the resin case (3). A coil (4) that is rotated, and one of the piezoelectric ceramic plate (5) and the metal plate (6) and one end (4a) of the coil (4) are commonly connected to each other. While being drawn out of the resin case (3) through the external connection terminal (12) of the other, the other of the piezoelectric ceramic plate (5) and the metal plate (6) and the other end (4b) of the coil (4) are , An electroacoustic transducer which is drawn out of the resin case (3) through the second and third external connection terminals (13, 14) respectively connected to each other.