JPS5816285Y2 - Telephone loudspeaker - Google Patents

Description

[Detailed description of the invention] This invention relates to a telephone loudspeaker system, and in particular, a telephone loudspeaker system that houses a loudspeaker system for receiving calls and a loudspeaker system for sending calls in the same housing, and that allows a user to make a call without touching the handset of the telephone set. This is what we are trying to provide.

Various attempts have been made to prototype telephone loudspeaker systems.

For example, being able to talk to someone from a distance without having to touch the receiver of a telephone is convenient because the person making the call can use their hands freely, making it possible to talk while driving a car, for example. .

However, when trying to configure such a loudspeaker, a microphone is placed to face the earpiece, and a speaker is placed to face the mouthpiece, and the received sound obtained from the microphone is amplified by an amplifier to drive the loudspeaker for communication. The speaker's voice must be converted into an electrical signal by a microphone and amplified, and the amplified output must be configured to drive a speaker placed opposite the mouthpiece.

Therefore, two sets of public address systems are required, one for receiving calls and one for sending calls.

Since electrical crosstalk exists between the mouthpiece and the earpiece of a telephone, the input of one loudspeaker and the output of the other loudspeaker are acoustically coupled to the earpiece and the mouthpiece.

The inputs and outputs of these two sets of loudspeaker devices are coupled together through an earpiece and a mouthpiece.

Since the received voice is emitted into the space by the speaker, this sound enters the microphone of the transmitting loudspeaker, which causes so-called howling, which is not practical.

For these reasons, conventional systems have only been put into practical use in which a loudspeaker is provided only on the receiving side, and only the received sound is amplified.

The purpose of this invention is to provide a telephone loudspeaker system which has a howling prevention function and can house two sets of loudspeaker systems, one for receiving and one for transmitting, in the same housing.

In this device, a signal of opposite phase is applied from one set of loudspeaker to the other, or from the other to one, and the signal emitted by one loudspeaker is transmitted to the other loudspeaker by crosstalk between the mouthpiece and the earpiece. This structure is designed to counteract the amplification of noise and prevent howling.

An embodiment of this invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of this invention.

In the figure, 1 indicates a handset of a telephone (not particularly shown),
Reference numeral 2 indicates an acoustic coupler acoustically coupled to the earpiece 1a and the mouthpiece 1b of the handset 1.

A microphone 3 is attached to the acoustic coupler 2 at a position facing the mouthpiece 1a, and a speaker 4 is attached at a position facing the mouthpiece 1b.

The microphone 3 and the speaker 4 are mounted upwardly in a housing 15, for example, as shown in FIG. 1b is configured to face the speaker 4.

The acoustic coupler 20 microphone 3 has a loudspeaker device 5 for receiving calls.
is connected to the speaker 4 of the acoustic coupler 2, and a loudspeaker device 6 for transmitting speech is connected to the speaker 4 of the acoustic coupler 2.

The loudspeaker device 5 for receiving calls includes a preamplifier 5a and a volume adjuster 5b.
, a mixer 5c, and a power amplifier 5d, which amplify the reception signal captured by the microphone 3 and send it to the speaker 7.
is driven, and the speaker 7 also emits the receiving sound.

The transmitting loudspeaker device 6 includes a preamplifier 6a, an automatic volume adjuster 6b, a negative phase signal extraction circuit 6c, and a manual volume setter 6d.
and a power amplifier 6e, amplifies the voice signal of the caller captured by the microphone 8, drives the speaker 4 provided in the acoustic coupler 2, and transmits the voice of one caller to the other party through the mouthpiece 1b.

In this invention, in the two sets of loudspeaker devices 5 and 6 configured as described above, one of the loudspeaker devices is configured to give an opposite phase component of the signal transmitted from the other loudspeaker device to the other one to cancel out the crosstalk signal. It is something.

The illustrated example shows a case in which a reverse phase signal is provided from the transmitting loudspeaker 6 to the receiving loudspeaker 5.

That is, the receiving loudspeaker 5 is provided with a mixer 5c, the transmitting loudspeaker 6 is provided with a negative phase signal extraction circuit 6c, and the negative phase signal extracted by the negative phase signal extraction circuit 6c is sent to the mixer 5c.
In addition to this, the configuration is such that it is canceled by an opposite phase signal, which is a signal component that crosstalks from the speaker 4 of the acoustic coupler 2 to the microphone 3.

FIG. 3 shows a specific configuration example of the negative phase signal extraction circuit 6c and the mixer 5c.

That is, the transmitting signal component is taken out from the emitter of transistor Q0 and given to manual volume setting device 6d, and then sent to power amplifier 6e.
is supplied to

- From the collector of transistor Q□, a signal having the opposite phase to the transmitting signal is taken out.

A signal having a phase opposite to that is applied to the amplifier 10 through the level adjuster 9, and is supplied to the output of the amplifier 10, the □ fuser 5c.

The mixer 5c can be constituted by, for example, resistors R□ and R2, and is supplied to the signal path of the loudspeaker device 5 for receiving calls by being biased by the resistors R and R2.

In this configuration, the polarity of the speaker 4 and the microphone 3 and the power amplifier 6e are adjusted so that the crosstalk component of the transmission signal appearing at the supply point A of the reverse phase signal is in the same phase as the transmission signal extracted from the emitter of the transistor Q□. Set the polarity of the preamplifier.

In this way, the transmitted signal component crosstalked to point A can be canceled by the reverse phase signal.

Furthermore, even if the amount of crosstalk between the mouthpiece 1b and the earpiece 1a differs depending on the telephone set, the amount of the negative phase signal can be varied by the level adjuster 9, so even if the amount of crosstalk varies, the voice can be received reliably. It is possible to cancel the signal components crosstalked to the public address system 5.

As explained above, according to this invention, a reverse phase signal is taken out from one loudspeaker, and the crosstalk signal transmitted to the other loudspeaker is canceled by the reverse phase signal. Even if the sound mixes into the microphone 8 and crosstalks to the loudspeaker device 5 for receiving the call via the handset 1, the mixer 5
Since the sound is canceled at step c, the sound will not be emitted from the speaker 7 again, so there is no possibility of howling occurring.

From the above, it is understood that the structure electrically prevents howling, but since this invention houses two sets of loudspeakers in the same housing, howling caused by crosstalk transmitted through the housing is also avoided. must be prevented.

Therefore, in this invention, the speakers 4 and 7 are constructed as shown in FIG.

That is, a bowl-shaped sound insulating body 11 formed of a rigid body is attached to the back side of the speakers 4 and 7 to prevent sound from being emitted from the back side of the speakers 4 and 7.

The speakers 4 and 7 configured in this manner are attached to the housing via a vibration isolating material made of a foam material such as molded brain.

For example, the speaker 4 constituting the acoustic coupler 2 is attached upward to the housing 15 via a vibration isolating material 12, as shown in FIG.

Further, the speaker 7 is similarly attached to the housing 15 via the vibration isolating material 12, as shown in FIG.

Microphones 3 and 8 are also connected to the housing 1 via the vibration isolating material 12.
5vc mounting bracket.

The attached state of the microphone 3 is shown in FIG. 2 in the drawing.

By attaching the speakers 4 and 7 and the microphones 3 and 8 to the housing 15Vc through the vibration isolating material 12 in this way, it is possible to prevent crosstalk generated by propagation l- in the housing 15, and thereby prevent howling. It is configured to do so.

In the above description, the microphone 3 is mounted opposite the earpiece 1a, but instead of the microphone 3, a commercially available telephone pink amplifier may be used.

Further, instead of a commercially available telephone pickup, an electromagnetic pickup as shown in FIG. 6 may be installed facing the earpiece 1a.

In this example, the electromagnetic pickup shown in FIG. 6 is constructed by winding a coil 14a around an E-shaped core or a pot-shaped core 13.

When the diaphragm vibrates inside the earpiece 1a, a K audio current is induced in the coil 14a, and an electrical signal can be obtained.

By using such an electromagnetic pickup, it is possible to prevent the sounds emitted from the speakers 4 and 7 from being directly input to the loudspeaker device 5 for receiving calls, which is convenient.

In addition, an auxiliary winding 14b is provided separately from the coil 14a as shown in FIG.
It is possible to cancel crosstalk without providing the reverse phase signal extraction circuit 6C as described above by passing a part of the signal applied to the signal.

In FIG. 1, reference numeral 16 indicates a switch provided in the acoustic coupler 20, and this switch 16 turns on and off the power of the loudspeaker devices 5 and 6 for receiving and transmitting calls. 1 on top of the acoustic coupler 2.

This is provided in order to be linked to the removal operation.

That is, when the handset 1 is placed on the acoustic coupler 2, the switch 16 is turned on, automatically turning on the power to the public address systems 5 and 6, and when the handset 1 is removed from the top of the acoustic coupler 2, the power is automatically turned on. It was designed to be turned off.

This configuration is extremely convenient for use.

FIG. 8 shows a specific embodiment of the loudspeaker according to this invention.

This embodiment shows a case in which a tape recorder is housed in the same housing so that the contents of a call can be easily recorded.

That is, in FIG. 8, numeral 17 indicates a tape recorder circuit.

18 is a bias oscillator, 19 is an erasing head, 20 is a recording/reproducing head, and 21 is a recording amplifier.

22 is an equalizer amplifier.

Also 23a, 23b. Reference numerals 23c are recording/reproduction changeover switches that are operated in conjunction with each other.

When the switches 23a to 23c are switched to P, they are in the reproduction state, and when they are switched to R, they are in the recording state.

During recording, a receive signal and a transmit signal are supplied to the equalizer amplifier 22 through amplifiers 24 and 25;
By appropriately setting the degree of amplification, it is possible to record the received signal and the transmitted signal at the same level.

In addition, the switch 16 provided in the acoustic coupler 2 has a contact 16a.
In conjunction with turning on and off the power of the entire device, the contact 16b switches the human power of the power amplifier 5d of the loudspeaker 5 to the output side of the acoustic coupler 2 and equalizer amplifier 22, and the power amplifier 5d and the speaker 7 can be switched so that they can also be used for playback on a tape recorder.

That is, when the receiver 1 is placed on the acoustic coupler 2, the contact 16b of the switch 16 contacts the fixed contact T□ side, and the received signal received by the acoustic coupler 2 is applied to the power amplifier 5, and the received signal is released from the speaker 7. I'm trying to make it sound.

Therefore, it works as a transmitting and receiving loudspeaker. On the other hand, when the receiver 1 is removed from the top of the acoustic coupler 2, the contact 16b of the switch 16 is switched to the fixed contact T2.

In this state, the reproduction equalizer amplifier 22 of the tape recorder is connected to the input side of the power amplifier 5d.

Therefore, when a telephone call is not being made using the public address system, by putting the tape recorder in the playback state, the playback signal is amplified by the power amplifier 5d and is emitted from the speaker r, allowing the user to listen to the recorded content of the call.

FIG. 9 shows an example of the external appearance of a public address system according to this invention.

As shown in this figure, a housing 15 of the loudspeaker according to this invention is shown.
is made into a flat shape and a telephone is placed on top of it.

An acoustic coupler 2 is provided next to the telephone set, on which a receiver 1 can be placed.

A microphone 8 is attached to the front to pick up the transmitted voice sound,
A tape recorder operation section 26 is attached next to it.

A clock device 27 is attached to the opposite side of the operating section 260.

The clock device 27 has a time setting function and is used to issue an alarm at the set time.

As explained above, according to this invention, simply by placing the receiver 1 on the acoustic coupler 2, the received signal is emitted from the speaker 7, and the voice of the caller is captured by the microphone 8 and transmitted by the loudspeaker 6. Since the sound is amplified by the speaker 4 and given to the mouthpiece 1b, the caller can talk to the other party even from a distance from the telephone set, and can talk to the other party even while working.

It is easy to understand that the public address system of this invention will be effective especially when car telephones become widespread.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an embodiment of this invention, Fig. 2 is a sectional view showing an example of an acoustic coupler used in this invention, and Fig. 3 is a system diagram showing an example of an embodiment of this invention.
The figure is a connection diagram showing a specific example of the main part of this invention.
The figure is a sectional view showing an example of a speaker used in the device of this invention, FIG. 7 is a sectional view showing an example of a suitable electromagnetic pickup, FIG. 7 is a system diagram showing the electrical configuration when this electromagnetic pickup is used, FIG. 8 is a system diagram showing a specific example of the device according to this invention, and FIG. The figure is a front view showing an example of the housing of the device according to this invention. 1: Handset, 2: Acoustic coupler, 3: Microphone, 4
: speaker, 5: loudspeaker for receiving calls, 6: loudspeaker for sending calls, 6c: negative phase signal extraction circuit, 5c second square.

Claims (1)

[Scope of utility model registration request] A loudspeaker system for transmitting and transmitting ambient sounds to the mouthpiece of a telephone set via an acoustic coupler; and a loudspeaker system for receiving calls that outputs the received sound obtained from the earpiece of the telephone set via the acoustic coupler from a speaker. , a casing for housing these together, a circuit for supplying a reverse phase signal from one of the transmitting and receiving loudspeakers to the other, and a rear surface of the speaker of the transmitting and receiving loudspeaker. 1. A telephone loudspeaker comprising: a sound insulator that covers the casing; and a vibration isolator inserted between the sound insulator and the casing.