JPH0514952A - Digital telephone system - Google Patents

Abstract

PURPOSE:To make it possible to suppress the large size of power source device and the cost up of the system to minimum even if the number of telephone to be connected and the total extension of a transmission line to be used for the connection are increased in a telephone system in which a main device (exchange device) and a telephone set to be connected with this are digitized and a digital transmission is performed for the sound signals between these. CONSTITUTION:A sound source 206 for the generation of various kinds of signal sound signal and a speech network means 209 performing a transmission control of the signal sound from this sound source and the control of a signal level are provided on an exchange device 20. These are eliminated from the side of telephone sets 10A, 10B, and the generation of signal sound, the control of sound level and necessary control at the time of performing speech by a lound speaker are executed on the side of the exchange device. The side of telephone set is constituted by being provided with telephone set control means 110A, 110B performing an input/output of sound signal and a signal sound output control in accordance with a received control signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital telephone system such as a PBX or a key telephone apparatus which digitizes and transmits a voice signal between a main unit and a telephone.

[0002]

2. Description of the Related Art Private branch exchanges (PBXs), key telephone systems, and the like have been put into practical use in which voice signals are digitized and transmitted between them and a telephone connected to them.

As described above, a method of digitizing and transmitting a voice signal between a telephone and a main device such as a PBX or a key telephone device to which the telephone is connected depends on the length of the transmission line as compared with the analog method. The voice level changes,
There is no problem that the frequency characteristic of the audio signal changes due to the characteristic impedance of the transmission line, and it is a method that has been widely spread in recent years.

FIGS. 6 to 8 are block diagrams showing conventional examples of such a digital telephone system. Here, FIG. 6 is a diagram showing the entire configuration, and FIGS.
Is a partially enlarged view of FIG.

A conventional system will be described with reference to the drawings.
The telephone system of the telephone 1 has two circuits, an analog circuit and a digital circuit.
Handset 1 as an analog circuit
01, microphone 102, speaker 103, and these handsets 101 and microphones 10.
2. A switch circuit 105 for switching the connection between the speaker 103 and the A / D / D / A converter 104. Also, as digital circuits, ringing tone, DTMF
A sound source 106 that produces various sounds such as a sound and a key confirmation sound that is a sound for confirming the operation at the time of key operation, a microphone 102, and a loudspeaker circuit 107 that performs a voice call transmission control for a loud voice call by a speaker 103. Alternatively, a multiplexing circuit 10 for digitally multiplexing or separating a voice signal (B channel) transmitted and received between the main device 2 and the telephone 1 and a control signal (D channel) between the main device 2 and the telephone 1.
8 and a speech network 109 that performs input / output on / off control of audio signals and various sound source signals and level control with an A / D / D / A converter 104 that performs mutual conversion between analog signals and digital signals. It is made up.

These communication systems are controlled by a control circuit 110 composed of a microprocessor or the like, and the control circuit 110 is placed under the control of the main unit 2 via a multiplexing circuit 108. There is. Further, the control circuit 110 includes a key input circuit 111 for inputting a key operation and a display 112 including an LED (light emitting diode) and an LCD (liquid crystal display) for displaying the state of the telephone 1.
Are connected. The power supply 113 for supplying power to the telephone 1 receives power from the transmission / feed line 3 which is a connection line between the main device 2 and the telephone 1.

The transmission / feed line 3 transmits a digitized voice signal and a control signal between the main unit telephone and the transmission / feed line 3 is supplied with a DC voltage from the main unit 2. Using this, the telephone 1 is supplied with power. The telephone 1 is connected to the transmission / feed line 3 via a transformer 114. The transformer 114 is used for distribution of a signal and electric power, the audio signal and the control signal isolated by the transformer 114 are transmitted to the multiplexing circuit 108, and the electric power is transmitted to the power source 113.

The main unit 2 has a multiplexing circuit 20 similar to that described above.
8, a transformer 214 for isolating signal components and power components, a trunk circuit 201 for connecting to an external line (local line), a control circuit 202 for controlling the movement of the entire system, and power for the entire system. Power supply 203
It consists of

The trunk circuit 201 has a different circuit configuration depending on whether the external line is an analog line or a digital line. However, since this difference is not relevant in this description, no particular distinction is made. Further, the above-mentioned other components of the main device 2 are all digital circuits.

The multiplexing circuit 208 and the trunk circuit 201 can time-divisionally send the digitized voice signal to the PCM highway 204, and take out from the PCM highway 204 to alternately transmit the voice signals. The multiplexing circuit 208 and the trunk circuit 201 are placed under the control of the control circuit 202 by the control bus 205. Power supply 20
The power supply 3 supplies power to the respective telephones 1 via the transmission / power supply line 3 together with the power supply in the main device 2.

The operation of the telephone system having such a configuration will be described.
A case where a telephone call is made between the extensions using the handset 101 will be described. When the telephone is off-hook in the handset call mode, the switch circuit 105 connects the transmitter and the receiver of the handset 101 to the A / D and D / A switch 104.

Next, when the operator performs a dial input by key operation, the dial number of the other party is input from the key input circuit 111 to the control circuit 110 by this key input, and the control circuit 110 receiving this input reads the dial information, This is sent to the multiplexing circuit 108 to be multiplexed, and then sent to the multiplexing circuit 208 of the main device 2 via the transformer 114, the transmission / feed line 3, and the transformer 214.

Then, the multiplexing circuit 208 separates the dial information, and the separated dial information is transmitted to the control circuit 202 via the control bus 205. In the control circuit 202, a control signal is transmitted to a control circuit of the other party's telephone (not shown) by a route reverse to this, a ringing tone is emitted from the sound source, and the off-hook by taking the handset of the other party operator causes the communication path to the handset. be opened.

The transmitted voice includes a handset 101, a switch circuit 105, an A / D / D / A converter 104, a speech network 109, a multiplexing circuit 108, and a transformer 11.
4, transmission / feed line 3, transformer 214, multiplexing circuit 20
8 to the PCM highway 204. Then, it is transmitted as the handset reception voice of the extension partner's telephone by the reverse route.

Thus, the handset call is performed. During a voice call, a voice signal is once transmitted from the speech network 109 to the voice amplification circuit 107, and the transmission and reception sounds are controlled to be switched so that the transmission and reception can be switched alternately. Except for this point, it is the same as the handset call. In addition, the extension-external line call is the same as the extension-line call except that the other party is connected via the trunk circuit 201.

[0016]

Although the digital telephone system operates in this manner, it has the following problems.

The inside of the telephone 1 is digitized to process the voice signal, but the digitization increases the circuit scale. In the case of analog circuits, a combination of an amplifier circuit and a switch circuit will suffice, but by digitizing it, it becomes necessary to perform arithmetic processing of audio signals, and an arithmetic unit (ALU)
ROM and RA in which programs for controlling this and this are written
M etc. are required. Further, since mutual conversion between analog and digital is required, an A / D / D / A converter for that is also required. In addition, the speech network 10
9, the loudspeaker circuit 107, the sound source 106, etc. are actually constituted by a digital signal processor (hereinafter abbreviated as DSP).

Therefore, the power consumption is significantly increased as compared with the analog telephone. Since the telephone set receives power from the main unit, the capacity required as the power source for the main unit must be increased according to the number of connected telephone sets, which is significantly higher than when connecting an analog telephone set. The size of the main device increases, which leads to an increase in the size of the main device, which also leads to an increase in cost. Further, the capacity of the power supply of the main device is determined at the manufacturing stage, so that the problem of power supply limitation arises when increasing the number of extensions of the telephone system. That is, _assuming that the feeding voltage is V _s and the line resistance of the transmission line is r, the power W that can be supplied to the telephone 1 is W = V _s ^2. /4r...(1)

Is given by Then, the same power as W is wastefully consumed by the resistance r of the transmission line. Therefore, as the system becomes larger, the total length of the transmission line inevitably becomes longer, so that the system becomes larger and the resistance r increases as the transmission line extends, and the power that can be supplied to the telephone decreases. That is,
Loss increases.

In order to prevent this, it is conceivable to increase the power supply voltage V _s , thicken the transmission line, or locally supply power to the telephone. Either method leads to an increase in size of the device and an increase in cost. It is inevitable.

Therefore, the object of the present invention is to
In a telephone system in which the main unit and the telephone connected to it are digitized and the voice signals between these main units and telephones are digitally transmitted, the number of connected telephones and the total extension of the transmission lines used for the connection increase. Even so, it is to provide a telephone system capable of minimizing the increase in size of the power supply device and the increase in system cost.

[0022]

In order to achieve the above object, the present invention is configured as follows. That is, it is composed of a main device (switching device) that performs an exchange operation and a plurality of telephones connected to this main device. Between the main device and each of the telephones, voice signals and control signals are multiplexed by digital transmission. In a telephone system in which the telephone is provided with voice signal expansion output means and voice signal input means, and the power supply of the telephone is supplied from the power supply of the main unit via a communication line. The main device includes a sound source that generates various signal tones, a speech network unit that controls on / off transmission of the signal tone from the sound source to the telephone, and a level of the transmitted signal, and the speech network unit. The transmission and reception of the signal of and the voice signal from the telephone are controlled so as to be carried out with respect to the telephone to be exchanged,
When transmitting and receiving a voice signal to and from a telephone set in a voice call mode, a control means is provided for controlling to give a control signal for controlling the voice call to the telephone, and each of the telephones is at least the speech network. Means and a sound source are removed, and the voice signal loudspeaker output means and the voice signal loudspeaker input means are controlled in accordance with the received control signal, and the voice to the voice signal loudspeaker output means and the voice signal loudspeaker input means is controlled. A telephone control unit for controlling signal input / output and signal sound output is provided and configured.

The control means of the main unit is provided with a function of controlling to obtain a confirmation sound by the operation from the telephone side from the sound source and send it to the operating telephone. It is configured by adding a function of controlling to send a control signal accompanying the operation of the own telephone to the main device.

[0024]

In such a structure, the main unit is provided with a sound source for generating various signal tones required on the telephone side,
There is a speech network means for controlling the on / off control and signal level of the signal sound output from this sound source,
A ringing tone, a DTMF tone, a key operation tone, etc. for a telephone are generated from a sound source, and are sent out to a telephone to be exchanged through a speech network means under the control of a control means on the main unit side. Send to the other party's phone. On the side of the telephone which receives this, a signal sound obtained by separating the multiplexed signal is sent to the communication system to notify the user of the telephone by sound. When the other party's telephone answers, the response signal is sent to the main device side, so that the control means of the main device forms a communication path to enable the exchange of voice signals. Also, in the case of making a voice call with a voice call, the control means on the main unit side knows this by the control signal from the telephone set to the voice call mode, and performs control for the voice call.
As a result, the telephone set in the voice call mode controls the switching of the voice signal voice output means and the voice signal voice input means, and the telephone call from the voice call element side becomes possible.

As described above, in the present system, the sound source for generating various signal sound signals necessary for the telephone side, which is conventionally provided in each telephone side, and the sending control and signal level control of the signal sound from this sound source are controlled. Move the speech network means to the main device and omit them from the telephone side, so that the main device side controls the generation of signal sounds and the control of voice level, and further the necessary control at the time of the voice call. As a result, the number of components on the telephone side is correspondingly reduced and the load is also reduced. Therefore, the power supply that must be supplied to the telephone side is smaller than before and the distance of the communication line becomes longer. , The loss will be smaller.

Therefore, the power supply capacity of the main unit can be suppressed, and even if the system becomes large, the power supply capacity of the main unit can be made significantly smaller than the conventional one, and the cost increase can be minimized, and Even if additional telephone terminals are installed, the degree of freedom will be greater than before.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 1 is a block diagram of the overall configuration according to an embodiment of the present invention. 2 and 3 are partially enlarged views thereof. In the following, since there are a plurality of telephones, the suffixes A, B, ... Are added to the reference numerals in the drawings in order to distinguish them, but the suffixes are omitted in the description unless necessary.

1 to 3, reference numeral 10 denotes a telephone, and the telephone communication system of the telephone 10 is divided into two systems, an analog circuit and a digital circuit. The analog circuit includes a handset 101, a microphone 102, and a speaker 10.
3, and these handset 101, microphone 102, speaker 103 and A / D / D / A converter 10
4 and a switch circuit 105 for switching the connection with the switch 4.

As the digital circuit, the main unit 2
Multiplexing circuit 108 for multiplexing or separating a voice signal (two B channels) and a control signal (D channel) exchanged with 0, A / D / D / for mutual conversion of analog signal / digital signal A sound source for producing various sounds such as a ringing sound, a DTMF sound, and a key confirmation sound that is a sound for confirming the operation of a key operator, which is provided on the telephone side only with the A converter 104, a microphone 102, a speaker. 10
The voice signal and various sound source signals are exchanged between the voice amplification circuit for controlling the voice transmission and the reception switching control for the voice communication by A.3 and the A / D / D / A converter 104 for performing the mutual conversion between the analog signal and the digital signal. The speech network for input / output on / off control and level control is omitted.

These communication systems are controlled by a control circuit 110 constructed by using a microprocessor or the like, and the control circuit 110 is placed under the control of the main unit 20 via a multiplexing circuit 108. There is. Further, the control circuit 110 includes a key input circuit 111 for inputting a key operation.
And a display 11 including an LED (light emitting diode) and an LCD (liquid crystal display) for displaying the state of the telephone 1.
2 is connected. The power supply 113 for supplying power to the telephone 1 receives power from the transmission / feed line 3 which is a connection line between the main device 20 and the telephone 10.

The transmission / feed line 3 transmits a digitized voice signal and a control signal between the main unit telephone and the transmission / feed line 3 is supplied with a DC voltage from the main unit 20. Using this, the telephone 1 is supplied with power. The telephone 10 is connected to the transmission / feed line 3 via a transformer 114. The transformer 114 is used for distribution of signals and electric power, the audio signal and the control signal isolated by the transformer 114 are transmitted to the multiplexing circuit 108, and the electric power is supplied to the power source 11.
Passed to 3.

The main unit 20 is a multiplexing circuit 20 similar to that described above.
8, a transformer 214 for isolating signal components and power components, a trunk circuit 201 for connecting to an external line (local line), a control circuit 202 for controlling the movement of the entire system, and power for the entire system. Power supply 203
Is equipped with. The trunk circuit 201 has a different circuit configuration depending on whether the external line is an analog line or a digital line, but since this difference is not relevant in this description, no particular distinction is made.

The above-mentioned other components of the main unit 20 are all digital circuits. The multiplexing circuit 208 and the trunk circuit 201 can time-divisionally send the digitized voice signal to the PCM highway 204, and can take out the digitized voice signal from the PCM highway 204 to alternately transmit the voice signals. The multiplexing circuit 208 and the trunk circuit 201 are placed under the control of the control circuit 202 by the control bus 205. The power source 203 transmits / transmits power along with power in the main device 20.
Electric power is supplied to each telephone 10 via the power supply line 3.

The main unit 20 in this system is conventionally
A sound source, a speech network, which was provided on the telephone side,
The loudspeaker circuit was relocated, and these were omitted on the telephone side. That is, in FIG.
Reference numeral 06 is a sound source, 207 is a loudspeaker circuit, and 209 is a speech network.

The functions of the sound source 206, the loudspeaker circuit 207, and the speech network 209 are the same as those described in the conventional example, but the input / output of the voice signal is performed by the PCM highway 204.
And the control circuit 202 performs this control via the control bus 205.

The operation of the telephone system having such a configuration will be described by taking a handset call between extension lines as an example. The key input by the operator is a key input circuit 111 as a dial number.
It is read by the control circuit 110A from A, and the multiplexing circuit 10
It is transmitted to the control circuit 202 as a control signal via 8A, the transformer 114A, the transmission / feed line 3A, the transformer 214A, the multiplexing circuit 208A, and the control bus 205.

The control circuit 202 analyzes this control signal and transmits the control signal to the control circuit 110B of the other party's telephone set 10B by the reverse route, and the control circuit 110B lights up the LED as an incoming call display on the display 112A. And LCD
To display characters.

Then, the ringing tone from the sound source 206 is sent to the PCM.
It is sent to the multiplexing circuit 208B via the highway 204 in sequence, and after being multiplexed there, via the transformer 214B,
Send to the transmission / feed line 3B. The telephone set 10B receives the signal via the transformer 114B and sends the signal component to the multiplexing circuit 108B. Then, the multiplexing circuit 108B separates the received signal and sends it to the A / D / D / A converter 104B, where it is converted into an analog signal, and then the switch circuit 10B.
It is transmitted to the speaker 103B through 5B.

This control is performed in the main unit 20 by the activation of the sound source 206 by the control circuit 202 and the output of the control signal to the telephone 10B, and on the telephone 10B side by the control circuit 110B in the telephone 10B controlled by this control signal. Done.

When the off-hook of the handset is performed on the other party's telephone 10B by the ringing sound from the speaker 103B, the control circuit 110B of the telephone 10B detects this and controls the main unit 20 by the same route as the key input. Tell circuit 202. In response to this, the control circuit 202 stops the operation of the sound source 206, and switches the control circuit 110A, 110B of the telephone 10A, 10B to the switch circuit 105A,
A control signal is generated and transmitted to connect the 105B to the handsets 101A and 101B. This creates a call path between both handsets 101A and 101B,
Handset call is possible.

As for the flow of the voice signal, the transmitted voice from the telephone 10A is the handset 101A and the switch circuit 1.
05A, A / D / D / A converter 104A, multiplexing circuit 1
08A, the transformer 114A, the transmission / feed line 3A, the transformer 214A, and the multiplexing circuit 208A are transmitted to the PCM highway 204. Then, the voice received by the telephone set 10B is transmitted from the PCM highway 204 to the handset 101B by the reverse route. It is also the same as transmitting the transmitted voice of the telephone 10B to the telephone 10A.

Although the telephone call is carried out in this manner, when the handset is hooked on one of the telephones 10A and 10B during the telephone call, the telephone control circuit 11
0A or 110B detects this and transmits it to the control circuit 202 of the main device 20, and the control circuit 202 of the main device 20 analyzes this and controls the control circuit 110 of both telephones 10A and 10B.
Blocking of call path and display 112 for A and 110B
Instruct to erase the display of A and 112B. And this is the end of the story.

During a voice call, for example, when the telephone 10A is set in the voice call mode, the telephone 10A,
The transmitted voice of 10B is once transmitted to the loudspeaker circuit 207 of the main device 20.
To the telephone 10A, 1
It is transmitted to 0B as a received voice.

That is, when transmitting from the telephone 10A, the transmitted voice from the telephone 10B is turned off by the loudspeaker circuit 207 of the main device 20 and is not transmitted to the telephone 10A. On the contrary, when the telephone is transmitting from the telephone 10B, the telephone
The voice transmitted from 0A is turned off by the voice amplification circuit 207 and cannot be transmitted to the telephone set 10B.

It goes without saying that this control is performed by comparing the loudness of the transmitted voice. Microphone 1 of each of the telephones 10A in the voice call mode is used for voice transmission and reception.
02A and speaker 103A.

The speech volume of the speaker 103A is adjusted by the speech network 209 of the main unit 20. That is, the telephone voice transmitted from the loudspeaker circuit 207 to the telephone 10A is once input to the speech network 209, where the level is adjusted here, and then the telephone 10A.
Is transmitted to.

This volume adjustment instruction is given by key input on the telephone 10A, and the instruction by this key input is transmitted from the control circuit 110A in the telephone 10A to the control circuit 202 of the main unit 20. And speech network 2
09 is inserted into the voice path and the adjustment amount is set by the control circuit 20.
Made by two. Besides this, the speech network 20
9 is inserted in the voice path in the following cases.

This is the case of an incoming call during a call, and when a call is made by a third party during a call, it is used for combining the received voice and the ringing sound from the sound source 206. In this case, the ringing tone is synthesized with the received voice while the level is suppressed to a low level. In addition, it is a case of a call service called three-way call, which is used when three people call
It is used for synthesizing voices received from two parties. All the input and output of the above audio signals are performed in the main device 20 by using the time division multiplexing method of the PCM highway 204. This situation is explained in FIGS. 4 and 5.

FIG. 4 shows the flow of a voice signal during a handset call. There are two PCM highways 204, series 1 and series 2, and audio signals of both parties talking here are flowing. For example, the time slot for time division is 2
It is assumed that the audio signal from the multiplexing circuits 208A and 208B is assigned to the time slot T8.

This is performed by the time slot designating signal, and each time a speech path is formed, the control circuit 202 searches for an empty slot and designates the empty slot each time. The time slot is generally 20 divisions as shown in FIG. 2 or 32 divisions.

FIG. 5 shows an example of the flow of a voice signal during a voice call. Two time slots are used to transmit the voice signal of the voice call, and in this example, time slots T7 and T11 are used. Public address circuit 207 is P
It has two sets of inputs and outputs to the CM highway 204.

The voice signal of the multiplexing circuit 208A is assigned to the time slot T7, and the multiplexing circuit 2
The 08B voice signal is assigned to the time slot T11. The voice signal of the loudspeaker circuit 207 is assigned to the time slots T7 and T11.

The transmitted voice from the multiplexing circuit 208A is input to the loudspeaker circuit 207 via the time slot T7.
Similarly, the voice transmitted from the multiplexing circuit 208B is input to the loudspeaker circuit 207 via the time slot T11.

The loudspeaker circuit 207 compares the magnitudes of both transmitted voices and selects the higher level. And
The selected voice signal is output as the received voice to the multiplexing circuit 208A or 208B via the time slots T7 and T11.

Here, the audio signal from the multiplexing circuit 208A is output to the multiplexing circuit 208B, and vice versa.
The audio signal from 8B is output to the multiplexing circuit 208A. The control circuit 202 specifies the time slot. The speech network 109, the loudspeaker circuit 107, and the sound source 10 provided in the telephone 10 in this way
6 can be moved into the main device 20.

As described above, in the telephone, except for the essential ones in the telephone, by moving to the main device, the number of constituent elements of each telephone can be reduced and the power consumption of the telephone can be reduced. . That is, the same power supply voltage V
Even with _s , the resistance value r of the transmission / feed line can be increased correspondingly, and the transmission distance can be extended.

Furthermore, since the electric power wasted in the transmission / feed line is reduced by the same amount as the energy saving on the side of the telephone, compared with the conventional system when the telephone is connected under the same conditions. The power supply capacity in the main unit can be greatly reduced. Furthermore, by moving some of the components in the telephone to the main device, the following advantages are brought about.

For example, as shown in FIGS. 1 to 3, since the sound sources 206 can be used in common, it is not necessary to have the same number of telephones. Since the control circuit 110 in the telephone has reduced the amount of information that has to be controlled, the cheaper M
It can be realized using PU. Although the speech network 209 in the main device is composed of the DSP as described above, it is suitable for the DSP because it can be combined a plurality of times.

That is, even if the DSP only executes a NOP instruction (no operation), it requires an arithmetic unit, a ROM, a RAM, a register, etc., and it is an instruction RO to collectively process a plurality of lines.
Since the increase can be dealt with only by increasing M, the integration efficiency is improved.

The loudspeaker circuits 207 do not have to be provided in the number of telephones. The same applies to the speech network 209. Not all telephones are used at the same time, and it is sufficient that the telephones are provided in proportion to the call volume. In particular, the speech amplification circuit 207 has a considerably smaller opportunity for the speech communication than the handset communication, so it can be said that a smaller number of circuits is sufficient. That is, it is possible to reduce the circuit scale of the main device by this amount, and this has a consequent ripple effect of cost reduction.

As described above, the present system is composed of the main device (switching device) for performing the exchange operation and the plurality of telephones connected to the main device, and the digital transmission is performed between the main device and each of the telephones. By multiplexing, a voice signal and a control signal are transmitted and received using a time slot designated by the main unit, the telephone has a voice signal input / output unit for a loud voice call, and the power source of the telephone is the main unit. In a telephone system in which power is supplied through a telephone line, a sound source for generating various signal sounds to the main device, a synthesis of signal sounds from this sound source and a transmission voice signal, and transmission of the signal sounds The time slot for the telephone set to be exchanged between the speech network means for performing the transmission and reception and the exchange of signals and voice signals between the speech network means. And a control means for controlling a voice signal to and from the telephone set to the voice call mode when the voice signal is transmitted / received to / from the telephone set to the voice call mode. Each telephone set is provided with telephone control means for controlling the voice call element in response to a received control signal and for inputting / outputting a voice signal to / from the voice call element and outputting a signal sound. In addition, the control means of the main device is provided with a function of controlling to obtain a confirmation sound by the operation from the telephone side from the sound source and send it to the operating telephone, and to the telephone control means on the telephone side. A function for controlling the control signal associated with the operation of the own telephone to be sent to the main unit is added, and the telephone control unit sends the control signal associated with the operation of the own telephone to the main unit on the telephone side. It is constructed by adding a function to control to.

In such a configuration, the main unit is provided with a sound source for generating various signal sound signals required on the telephone side, a synthesis of the signal sound from this sound source and a transmission voice signal, and a signal sound transmission. There is a speech network means to do, ringing to the telephone, DTMF tones,
The key operation sound is generated from this sound source, and this is sent out using the time slot for the target telephone to be transmitted / received under the control of the control means on the main unit side, and this is multiplexed to the other telephone. Then, the telephone side receiving this signal sends a signal sound obtained by separating the multiplexed signal to the communication system to notify the user of the telephone by sound. When the other party's telephone answers, the response signal is sent to the main device side, so that the control means of the main device forms a communication path to enable the exchange of voice signals.

Further, in the case of making a voice call for a voice call, the control means on the main unit side knows this by the control signal from the telephone set to the voice call, and controls for the voice call. It is said that the telephone set in the voice call mode enables the call from the voice call element side by controlling switching of the voice call element.

As described above, in the present system, the sound source for generating various signal sound signals required on the telephone side, which is conventionally provided on each telephone side, and the control of sending out the signal sound from this sound source and controlling the signal level are provided. Move the speech network means to the main device and omit them from the telephone side, so that the main device side controls the generation of signal sounds and the control of voice level, and further the necessary control at the time of the voice call. As a result, the number of components on the telephone side is correspondingly reduced and the load is also reduced. Therefore, the power supply that must be supplied to the telephone side is smaller than before and the distance of the communication line becomes longer. , The loss will be smaller. Therefore, the power supply capacity of the main device can be suppressed, and even if the system becomes large, the power supply capacity of the main device can be significantly reduced compared to the conventional one, and the cost increase can be minimized.
Even if a telephone terminal is added later, the degree of freedom becomes greater than before.

The present invention is not limited to the embodiments described above and shown in the drawings, and it is needless to say that the present invention can be appropriately modified and implemented without departing from the scope of the invention. Then, the telephone was moved from the telephone to the main device, including the sound source, the loudspeaker circuit, and the speech network.However, if the system does not carry out the loud voice call, the loudspeaker circuit is originally unnecessary. It can be deformed as necessary, such as by moving it.

[0066]

As described above in detail, according to the present invention, in the telephone system in which the main device and the telephone connected to the main device are digitized, the number of telephones to be connected and the total extension of the transmission lines used for the connection are extended. It is possible to provide a telephone system in which the increase in the size of the power supply device and the increase in the system cost can be suppressed to the minimum even if the power consumption increases.

[Brief description of drawings]

FIG. 1 is a block diagram of an overall configuration showing an embodiment of the present invention.

2 is a partially enlarged view of the configuration of FIG.

FIG. 3 is a partially enlarged view of the configuration of FIG.

FIG. 4 is a timing chart for explaining the operation of the device of the present invention.

FIG. 5 is a timing chart for explaining the operation of the device of the present invention.

FIG. 6 is a block diagram for explaining a conventional example.

7 is a partially enlarged view of the configuration of FIG.

FIG. 8 is a partially enlarged view of the configuration of FIG.

[Explanation of symbols]

10A, 10B ... Telephone, 20 ... Main device, 101 ... Handset, 102 ... Microphone, 103 ... Speaker, 111 ... Key input circuit, 108, 208 ... Multiplexing circuit, 202 ... Control circuit, 203 ... Power supply, 206 ... Sound source,
207 ... Loudspeaker circuit, 109 ... Speech network, 1
10 ... Control circuit.

Claims (2)

[Claims] 1. A switching device for performing a switching operation and a plurality of telephones connected to the switching device, wherein voice signals and control signals are transmitted between the switching device and each of the telephones by multiplexing by digital transmission. In a telephone system in which the telephone is provided with voice signal loudspeaker output means and voice signal input means while being exchanged for exchange control, and the power source of the telephone is supplied from the power source of the exchange device through a telephone line. The switching device includes a sound source for generating various signal tones, a speech network means for controlling on / off transmission of the signal sound from the sound source to the telephone and a level control of the transmitted signal, and the speech network means. The transmission and reception of the signal from the telephone and the voice signal from the telephone are controlled so as to be carried out with respect to the telephone to be transmitted and received, When transmitting and receiving a voice signal to and from a telephone set in a voice call mode, a control means is provided for controlling to give a control signal for controlling the voice call to the telephone, and each of the telephones is at least the speech network. Means and a sound source are removed, and the voice signal loudspeaker output means and the voice signal loudspeaker input means are controlled in accordance with the received control signal, and the voice to the voice signal loudspeaker output means and the voice signal loudspeaker input means is controlled. A digital telephone system comprising a telephone control means for controlling signal input / output and signal sound output. 2. A switching device for performing a switching operation and a plurality of telephones connected to the switching device, wherein a voice signal and a control signal are multiplexed between the switching device and each of the telephones by digital transmission. In the telephone system in which the telephone has an audio signal loudspeaker output means and an audio signal input means, and the power supply of the telephone is supplied from the power supply of the main device through a telephone line, the exchange device is exchanged. Is a sound source for generating signals of various signal tones, a speech network means for controlling on / off transmission of signal sounds from the sound source to the telephone and a level control of the transmitted signal, a signal from the speech network means and a telephone Control of sending and receiving of the voice signal of the target telephone to be sent and received In transmitting and receiving a voice signal to and from the set telephone, control is performed so as to give a control signal for voice communication control to the telephone, and a confirmation sound by an operation from the telephone side is obtained from the sound source to operate the telephone. And a control means for controlling to send to each of the telephones, at least the speech network means and the sound source are removed from each of the telephones, and the sound signal loudspeaker output means and the sound signal are output according to the received control signal. A digital telephone system, comprising: a telephone control means for controlling the voice input means and for transmitting a control signal associated with the operation of the own telephone to the main unit.