JPS63102496A - Piezo-electric receiver with coil - Google Patents

Abstract

PURPOSE:To make a piezo-electric receiver usable even to a person who has difficulty in hearing, by coupling each input terminals of a piezo-electric sound producing body and coils directly or by means of a driven circuit element. CONSTITUTION:One of the electrodes formed on both sides of a ceramic piezo-electric body 27 is directly coupled with a vibrator input terminal 30 and the other is coupled with another vibrator input terminal 26 through a diaphragm 24. A sound hole 22, through which acoustic waves are radiated from the piezo-electric vibrator, is provided in a front case 21. Moreover, a coil 23 and their input terminals 25 and 31 are simultaneously provided in the front case 21. The input terminal and vibrator input terminal 26 and 30 are fixed to a back case 32 and a leakage hole 29 and acoustic resisting material 28 are provided in the case 32. Both of the cases 21 and 32 are closely fitted and fixed to each other so as to firmly fix the diaphragm 24.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a piezoelectric handset with a coil, which is used as a handset for a telephone or an intercom, and which provides a convenient structure particularly for hearing-impaired people when using a telephone. be.

BACKGROUND OF THE INVENTION Sounding bodies used in telephone and intercom handsets include the most common electromagnetic type, electrodynamic type with low input impedance, and piezoelectric type with high input impedance.

Based on the principle of operation, the former two generate magnetic flux by passing current through the coil, so some of the magnetic flux leaks to the outside, albeit more or less. However, since the latter utilizes the piezoelectricity of the material, no magnetic flux is generated.

Hearing aids for people with hearing loss usually use a condenser microphone to pick up voice directly, and for telephones, a pick-up coil is used to pick up the telephone call signal in the form of leakage magnetic flux.

As a telephone receiver, it is necessary to leak magnetic flux in order to be compatible with a hearing aid having a pickup coil. In the case of an electromagnetic type or an electrodynamic type, this can be done easily, or in the case of a piezoelectric type, a new mechanism for leaking magnetic flux is required.

FIG. 3 shows a cross-sectional view of a conventional electrodynamic handset.

1 is a diaphragm, and a front case 2 is provided with a sound hole 3. A coil 4 is bonded to the diaphragm 1. Coil 4 is magnet 5
It is housed in a gap 8 formed between an inner pole 6 and an outer pole 7 made of a magnetic material and fixed by adhesive. The rear case 9 is provided with a leak hole 1o that determines the frequency characteristics of the receiver and an input terminal 11.

In operation, when a call signal is applied to the input terminal 11, a signal current flows through the coil 4, and since the coil 4 is in the magnetic field formed in the gap 8 between the inner pole and the outer pole, Fleming's left-hand rule is applied. Accordingly, the coil 4 moves in directions perpendicular to the direction of the current and the direction of the magnetic field, respectively. Therefore, the diaphragm 1 to which the coil 4 is attached vibrates according to the value of the current flowing through the coil 4. The vibration becomes a sound wave and is emitted from the sound hole 3.

For people with hearing loss, a portion of the magnetic flux created by the signal current flowing through the coil 4 leaks out of the handset and is converted into a current by the pickup coil of the hearing aid installed in the hand-sent earpiece, thereby amplifying the signal and transmitting it from the earphone. It was possible to hear what was being said by amplifying the sound or by stimulating the skull.

Problems to be Solved by the Invention In such a conventional configuration, it was easy to leak the magnetic flux corresponding to the call signal to the outside, but the piezoelectric type does not have a coil, and due to its operating principle, It was also impossible to leak magnetic flux.

The present invention solves these problems and aims to provide a structure of a telephone receiver that can be used by people with hearing loss even when a piezoelectric receiver is used.

Means for Solving the Problem In order to solve this problem, the present invention consists of a piezoelectric sounding body using a ceramic piezoelectric body and a coil, and an input terminal to the piezoelectric sounding body and an input terminal to the coil. In each case, each input terminal is connected directly or by a receiving circuit element.

In this configuration, when a call signal is applied to the input terminal, current flows through the coil and the piezoelectric body, and the coil generates a magnetic flux according to the call signal, which in turn sends an induced current to the hearing aid pickup coil attached to the outside of the handset earpiece. bring about Further, the current flowing through the ceramic piezoelectric body causes the vibrator to deform in accordance with the call signal, generating sound waves that pass through the sound hole of the handset and reach the ear through the handset earpiece and can be heard.

That is, a hearing-impaired person can hear the content of a call due to leakage magnetic flux from the coil, and a healthy person can hear the content of a call due to air vibration caused by deflection of a vibrator using a ceramic piezoelectric body.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a piezoelectric telephone receiver with a coil according to an embodiment of the present invention. The coil-equipped piezoelectric receiver consists of a piezoelectric vibrator made of a diaphragm 24 to which a ceramic piezoelectric material 2 is bonded, a front case 21, a back case 32, and a coil 23. One of the electrodes formed on both sides of the ceramic piezoelectric body is directly connected to the vibrator input terminal 30, and the other is connected to the vibrator input terminal 26 via the diaphragm 24. A sound hole 22 is provided in the front case 21 and emits sound waves generated by the bending vibration of the piezoelectric vibrator, resulting in sound that can be heard by a healthy person. In addition, in this embodiment, the front case 21
Although the coil 23 and the coil input terminals 24 and 31, which are input terminals to the coil 23, are provided at the same time, it is also possible to use these coil-related components as separate parts. Input terminals to the piezoelectric vibrator, vibrator input terminals 26 and 30 are fixed to the rear case 32. Furthermore, a leakage hole 29 and an acoustic resistance material 28 are provided, which have an important influence on the frequency characteristics of the handset. The front case 21 and the rear case 32 are closely fixed to each other to securely fix the diaphragm 24. As described above, the coil-equipped piezoelectric receiver of the present invention has separate input terminals for the piezoelectric vibrator and the coil. When this piezoelectric receiver with a coil is attached to a handheld device, the coil is placed on the front of the receiver to increase the leakage magnetic flux from the coil.

Fig. 2 is a wiring diagram showing the connection method between each terminal of the piezoelectric receiver with a coil according to the present invention. d shows an example in which a resistor is connected in series to a piezoelectric sounding body and a coil is connected in parallel, and d shows an example in which a coil, a resistor, and a piezoelectric sounding body are connected in series.

As described above, according to this embodiment, the input terminal to the vibrator of the piezoelectric sounding body and the input terminal to the coil are provided separately, and the input terminals are coupled directly or by a passive circuit element, thereby generating a piezoelectric Even when a handset is used, the telephone can be used by people with hearing loss. In addition, the telephone circuit and coil,
It is possible to widen the selection range of the piezoelectric sounding body connection method, and it is also possible to adjust the frequency characteristics of the receiver.

Although not mentioned in the embodiment, by forming the bobbin around which the coil is wound and the front case from an electrical insulator, it is possible to prevent damage to the semiconductor circuit due to static electricity charged on the human body.

Effects of the Invention As described above, according to the present invention, there is a piezoelectric sounding body consisting of a vibrator made of a ceramic piezoelectric body bonded to a metal plate, a front case and a back case, and a coil, and an input terminal to the piezoelectric sounding body. By providing input terminals to the coils and coupling the input terminals directly or through passive circuit elements, it is possible to obtain the effect that even a piezoelectric receiver can be used by a hearing-impaired person.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a piezoelectric receiver with a coil according to an embodiment of the present invention, Fig. 2 is a wiring diagram of the coil and piezoelectric sounding body, and Fig. 3 is a sectional view showing a conventional electrodynamic receiver. be. 21...-Front case, 23...Coil, 2
5゜31... Coil input terminal, 26.30...
... Vibrator input terminal, 2. ... Ceramic piezoelectric body. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 2 Figure 2 (a) (b) (C) (d) Figure 3 6 Internal food

Claims (1)

[Claims] A vibrator in which a ceramic piezoelectric body is bonded to a metal plate, a coil, an input terminal to the vibrator, and an input terminal to the coil are provided, and the input terminals are connected directly or by a passive circuit element. A piezoelectric telephone receiver with a coil.