JPS5831068B2 - Buttondenwasouchiniokel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a button telephone device that selects a handset by sending out a supply current according to a selection operation performed within a main device, and calls the selected handset using an individual voice calling signal. This is related to the telephone communication system.

In this type of conventional system, as shown in FIG. 1, the selection circuit 2 selects N call signal lines 41° 4□ . Then, the voice call signal from the main amplifier 3 is sent to the selected one of the N call signal lines, and the handset 50, 52
. . 5n, a voice call is made through the calling amplifier 6 and speaker 7 of one handset connected to the selected calling signal line.

Therefore, when the called party answers, he or she must use the handset of the handset.

Furthermore, if the responder is not nearby, the calling party cannot grasp the situation of the responder and is therefore forced to wait for a long time.

Furthermore, there was no device that allowed a specific operator to individually call a handset and make a call.

In view of the above points, the present invention has been made to solve such problems, and its main purpose is to make it possible to make simple and inexpensive hands-free calls using existing calling lines,
To provide a call method in a button telephone device in which a telephone for a specific operator is added in addition to a normal handset, and each handset can be forcibly called by voice from this telephone, and the handset can answer and call hands-free. It is something.

Still another object of the present invention is to provide a telephone call system using a key telephone device which does not cause crosstalk and prevents eavesdropping when making a forced individual call call from the above-mentioned telephone set for a specified operator.

In order to achieve such an object, the present invention adds a required number of handset microphones or microphones and amplifiers controlled by a ringing signal line, and selectively operates these handsets by direct current from the ringing signal line. The output is sent back to the main device through one common line, and one voice switch installed in the main device controls the calling voice signal and answering voice signal. An individual calling circuit for making calls is provided to allow hands-free calls that do not cause crosstalk and prevent eavesdropping.

The present invention will be described in detail below using the drawings.

FIG. 2 is a block diagram schematically showing an embodiment of a telephone call system in a key telephone device according to the present invention.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same parts or corresponding parts, 41, 4□...4 is a calling signal line that has both a calling signal sending function and a power supply function, 5□...
5n is 5□ as a slave unit.

. . . 5 is a button telephone circuit included in the handset, 8 is an amplifier for response signals, and 9 is a voice switch for switching transmission/reception controlled by, for example, a response voice signal from the handset. These are connected to the selection circuit 2 and the main Amplifier 3, extension connection tube J
It constitutes the main device 1 together with the control circuit 30.

'10. ．． to□...10n is a microphone, 11□
, 112...11n are call signal lines 41, 42...4
Microphone amplifiers are operated by the power supply l from n, and these form a response signal sending section, which is connected to the calling amplifiers 6□, 62...6n and the speakers 71, 72... ...7n and the required number of slave units 5
1, 52...5n.

12 is a response signal line. 191. ,．． 19n is a control circuit for individual calling, which is controlled by the individual calling switches 21, . . . 21n of the individual calling circuit 20,
This is a circuit that enables voice calls from 4.

22 is a transformer 22□, 222 is a winding of the transformer, 23 is a capacitor, and 25 is a blockage wire for supplying direct current to the telephone 24 for a specific user.

26 to 28 are power supply terminals, respectively.

In a device configured in this manner, for example, when the handset 51 calls the handset 5° and performs mutual extension communication,
When you lift the handset and dial the extension number of handset 5n,
The signal is input to the main device 1 through the tl, is controlled by the extension connection control circuit 30 including a counting circuit, and the selection circuit 2 selects the handset 5n, forming an extension calling loop.

Next, when the voice is sent from the handset of the handset 5□, a ringing audio signal (hereinafter referred to as ringing signal) sent from the main amplifier 3 is output through the ringing signal line 4n selected by the selection circuit 2. The call amplifier 6n and speaker 7° of the selected handset 5n are activated to make a call.

At the same time, the microphone amplifier 11n is activated by the power supply from the call signal line 4n, and the microphone 10
A response voice signal (hereinafter abbreviated as response signal) is transmitted from response signal line 12 to response signal amplifier 8 in main device 1.
will be sent to.

Furthermore, the output of the response signal amplifier 8 is the voice switch 9
The call signal and response signal are controlled and switched between sending and receiving.

Here, as the transmission/reception switching control means in this voice switch 9, the switching operation may be performed by a voice call signal from the calling side, or the input signal may be determined by comparing the two as in a normal hands-free call. This method can also be applied to a method in which the switching operation is performed on the priority side of the level or the like.

In the above embodiment, it is clear that the case in which the calling amplifiers are distributed in each slave unit 5 and the central amplifier in the main unit 1 can be used in exactly the same manner. If a microphone such as a carbon microphone is used, a microphone amplifier is not required.

Next, the individual calling operation from the specific operator's telephone 24 will be explained.

First, raise the handset of the specified operator's telephone 24 and press the pushbutton switch corresponding to the called slave, for example 21□ to form a circuit. (■Power supply) - Line ring 22, -Push button switch 21, -Individual call control circuit 191 U output amplifier"=ii□Earth (e power supply) Ichlophone amplifier The terminal 27 (■power supply) - wire ring 25 - specified operator telephone 24 -
Direct current flows through the route between wire ring 25 and terminal 28 (e power supply), making it possible to transmit calls.

Therefore, the voice signal sent from the transmitter of the specified user telephone 24 is transmitted to the coil 2 of the transformer 22 via the capacitor 23.
22, induced in the wire ring 22, passed through the above-mentioned activation loop, and amplified by the calling amplifier 61, and the speaker 7,
is output from.

By pressing the pushbutton switch in this manner, an individual calling operation can be made from the telephone 24 of the specified operator.

FIG. 3 is a detailed circuit configuration diagram showing a specific embodiment of the present invention, and the same reference numerals as in FIGS. 1 and 2 indicate the same or corresponding parts.

In this embodiment, as a switch for switching between transmission and reception during hands-free calling, the output electrodes, for example, the emitters of the transistors in the output stage of the response signal sending part of each slave device are all connected in parallel directly or via a diode, and 1 constitutes an emitter follower circuit with one resistor 13 provided in transistor 1, and the emitter follower circuit of this transistor is used as a switch.

That is, 140, 14□...14n are transistors at the output stage of the response signal sending section, and the collectors are resistors 158, 152...
... Call signal line 4□ via 15n.

42...4n and Zener diode 1
61.162...16n, and the emitters are forward-connected diodes 14a□, 14a20.
.

It is connected to the response signal line 12 via 14an, and its base is further connected to the output terminals of microphone amplifiers 110, 112...11n via capacitors 17□, 172...17n.

Here, the cathodes of the diodes 14 to 14an connected to the emitters of the transistors 14□ to 14n are all connected in parallel to each other, and the connection point is connected to the resistor 13 of the main device 1 via the response signal line 12. , these constitute an emitter follower circuit.

In a circuit having such a configuration, the selection circuit 2 of the main device 1
When a DC voltage is supplied to a selected one of the calling signal lines 41, 42, . operates, and a DC voltage is generated on the response signal line 12 along with a response signal.

Here, cordless handset 5□ where voltage is not supplied to the calling signal line.
...5n transistors 142 to 14 and diodes 14 to 14an are reverse pi n
Since it becomes a2 as, it does not affect the resistor 13 which is a load.

Therefore, only the signal from the slave unit to which power is supplied is input to the response signal amplifier 8.

The voice switch 9 can control the calling signal and response signal.

Note that the operation of making a hands-free call using the calling signal line is completely the same as in FIG. 2, so a description thereof will be omitted here.

In the above embodiment, the diode can be omitted if the reverse bias voltage 1, which is explained in the case where the diode is connected to the emitter of the transistor, is equal to or lower than the reverse breakdown voltage between the base and emitter of the transistor.

As described above, the present invention eliminates the need to provide a switch means such as a relay that is activated by the DC supply voltage within the slave unit, and therefore consumes less power.

In addition, the circuit configuration can be simplified by reducing the number of circuit parts, and regardless of the number N of slave units, the transistors 141, 142, . . . 12 can be supplied.

Next, we will discuss the individual calling operation from the specified operator's telephone 24. First, by pressing the pushbutton switch 211, the DC current applied to the calling amplifier 6□, the micro amplifier 18, and the transistor 141 is , (Autopsy power supply terminal 26 - wire ring 22, - pushbutton switch 21, - diode 19b - call amplifier 6° - ground route, and (dissection power supply terminal 26 - wire ring 22 □ - pushbutton switch 21 A current flows through the route of □-diode 19b1-resistor 15, -microphone amplifier 11□-ground.

On the other hand (field power supply terminal 26 - wire ring 22, - pushbutton switch 211 - diode 19b1 - resistor 15□ - transistor 14□ - diode 14a8 - response signal line 12 -
The route between the resistor 13 and ground is between the collector and emitter of the transistor 19a0 or between the terminal 26 and the 8th wheel 21.
, -Push button switch 21□ -Resistor 26, -A current flows through the base emitter ground route of transistor 19a1 and turns on.

Therefore, the base potential of the transistor 14 becomes the ground potential, and by turning off the collector-emitter of the transistor 14, direct current is blocked.

As a result, the output of the microphone amplifier 111 is attenuated due to a decrease in AC impedance in the ON state between the collector and emitter of the transistor 19a1 connected in parallel to its output terminal, and due to the disconnection of the DC bias of the transistor 14. Decrease in magnification and diode 1
The output signal of the microphone amplifier can be greatly attenuated by the attenuation effect caused by the increase in AC impedance caused by the interruption of the 6□ DC current.

As explained above, by configuring the microphone amplifier to operate normally when making a call from the main device A, and greatly attenuating its output when making a call from the push button switch, it is possible to Interference and crosstalk can be prevented.

In the embodiment shown in FIG. 3, the transistors 14□ to 14n
Although an example has been shown in which the output electrodes of the transistors 19a1 to 19an are connected to the bases of the microphones 10.
10n and the output electrodes of the transistors 141 to 14n, it goes without saying that similar effects can be obtained.

Furthermore, although the case where the output transistors 14, to 14n are configured as emitter followers has been described, the present invention can be practiced with other follower output stage formats.

As explained above, according to the present invention, in a known key telephone system, the existing call signal line can be used as is without adding a new line, and a microphone or a microphone and a microphone amplifier can be installed on the handset side. By using a single response signal line common to the required number of handsets, and controlling the ringing signal and response signal with a voice switch installed in the main device, it is possible to make simple and low-profile hands-free calls. In addition, when a call is made, the called party can respond immediately, and even if no one is nearby, the situation can be understood from the sound heard through the microphone on the called party's side. Because you can do this, you don't have to carry the load for a long time, so you don't waste time.

Furthermore, since there are several unused wires remaining in the cable connecting the key phone main device and the handset, if these wires are used as response signal wires, there is no need to add new wires.

In addition, each handset from the specified operator's telephone, 571Jl
-1 = call can be made by simply pressing a pushbutton switch, and when making a call, the gain of the microphone amplifier for hands-free calls is changed depending on the calling system, and the Even a hands-free telephone call system using a microphone signal response line can eliminate call interference, crosstalk, etc., so its practical effects are extremely limited.

Furthermore, in the present invention, there is no need to provide a special switch means such as a relay in the slave unit as a means for receiving a response signal from the slave unit by the main unit, so power consumption is reduced and the configuration is simple. It is extremely effective in terms of cost reduction due to simplification and also in that response signals can be faithfully transmitted regardless of the number of slave units.

Furthermore, the effects of this invention are extremely significant in terms of improving the performance and reliability of devices using the present invention.

[Brief explanation of the drawing]

FIG. 1 is a connection system diagram showing an example of the configuration of a conventional hands-free telephone system, and FIGS. 2 and 3 are circuit diagrams showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Main device, 2... Selection circuit, 3... Main amplifier, 40, 4□~4n... Calling signal line, 50, 52~5
o...Slave unit, 5□o, 5□. ~5no...button telephone circuit, 61.62 s~6
o... Calling amplifier, 70, 72-7n... Speaker, 8... Response signal amplifier, 9... Voice switch, 10□, 102-10n... Microphone, 11
1,112~11n...Microphone amplifier, 12.
...Response signal line, 13...Resistance, 141, 14□~1
4. ...transistor, 14a□, 14a2-14a
n...Diode, 15□, 152~15n...Resistance, 161, 16□~16°...Diode, 1
71,17□~17n...Capacitor, 181.18
2-18o...Microphone amplifier, 19□. 19□〜19. ...Individual call control circuit, 19a1゜19a2 to 19an...Transistor, 19b1゜1
9b2...19bn...Diode, 20...Individual call circuit, 211, 212-21n...Individual call switch, 22...Transformer, 23...Capacitor,
24...Specified operator telephone, 25...Block line, 26
, 27, 28... Power supply terminal, 29, 30... Extension connection control circuit.

Claims (1)

[Scope of Claims] 1. In a button telephone device that selects a handset by sending out a supply current according to a selection operation performed within the main device, and calls the selected handset using an individual voice calling signal, A common control line is provided between the device and each slave unit, and a response signal output unit configured to send a response signal to the common line in response to the supplied current is provided to each of the required number of slave units, and , the main device is equipped with a voice switch for switching the handset to send and receive calls in response to either the voice individual call signal from the caller or the response signal, thereby enabling hands-free calling. 1. A telephone call system in a button telephone device, characterized in that the key telephone device is configured to be able to perform the following operations, and further includes an individual calling circuit for forcibly calling the handset even during the hands-free call. 2. The output stage of the response signal output section of each slave device is formed in a follower circuit connected to the common resistor on the main device side via the common line, and is further connected to a call from the push button of the individual call circuit. In response, a direct current is supplied to a base circuit of a transistor used in an amplifier in the response signal peak portion, and a direct current is supplied to a receiving circuit for the voice individual call signal in the slave unit via a diode. A telephone call system in a button telephone device according to claim 1, characterized in that the key telephone device comprises means.