JPH0530221A - Telephone system with exchange function - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a telephone system having a switching function in which an attached telephone captures a telephone line and makes an extension call in a hold state without releasing the once captured telephone line during an outside line call. [Composition] A telephone system in which a main connection device A and at least one or more attached telephones 19 are connected in parallel to a telephone line 1, and the main connection device A detects the usage state of the telephone line 1 by the attached telephones 19. A line state detection circuit 17 for
During the extension transfer operation on the main connection unit A side, when the line state detection circuit 17 detects that the telephone line 1 is not used, the telephone line 1 once captured is opened to make an extension call, When the line state detection circuit 17 detects that the telephone line 1 is in use, the main control circuit 18 is provided to control the telephone line 1 that has been once captured to be put on hold and to make an extension call.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone system in which a main connection device having a plurality of terminals and capable of extension transfer and at least one or more attached telephones are connected in parallel to a telephone line. More specifically, the present invention relates to a telephone system having an exchanging function for performing an extension calling operation on the side of a main connection device in accordance with a line usage state of an attached telephone.

[0002]

2. Description of the Related Art Recently, in the field of telephones, there have been provided various types of systems constructed to meet the needs of users.

For example, a cordless telephone having a plurality of cordless handsets and an ordinary telephone are connected in parallel to a telephone line, and each cordless handset, a parent device and a telephone connected in parallel (telephone attached) to an outside line. There is provided a telephone system in a use form that enables a user to make a call.

Incidentally, cordless telephones and home telephones have a simple exchange function. According to this exchange function, the extension transfer operation captures the telephone line immediately when the extension telephone is off-hook, and then when the extension button or the like is pressed, the extension of the telephone line is released and the extension call is made. Is becoming

[0005]

As a result of connecting a cordless telephone having such a simple exchange function and an attached telephone in parallel to a telephone line, the attached telephone captures the telephone line, and the cordless telephone is used during an outside line call. When the extension transfer operation described above is performed, the following problems occur.

[0006] That is, when an off-hook is made on either the cordless telephone handset or the base unit during an outside line call on the attached telephone, the off-hook handset or base unit captures the telephone line and then pushes the extension button to call the extension line. If an instruction is given, the telephone line is uncaptured at that point, the telephone line is opened, and an extension call is made. That is, when the on-hook telephone is on-hook, the call is completely disconnected and the outside line cannot be transferred.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make an extension call as a hold state without releasing the once captured telephone line during a telephone call of an outside line by an attached telephone. The purpose of the present invention is to provide a telephone system that enables extension hold transfer.

[0008]

In order to solve the above problems, a telephone system having a switching function according to the present invention comprises a main connection device having a plurality of terminals and capable of extension transfer, and at least one or more of them. In the case where a telephone is connected in parallel to a telephone line, the main connection device, a line state detection unit for detecting the use state of the telephone line by the auxiliary telephone, and an extension transfer operation on the main connection device side, When the line status detecting unit detects that the telephone line is not being used, the once-acquired telephone line is released to make an extension call, and the line state detecting unit detects that the telephone line is in use. In this case, the telephone line once captured is put on hold and a control unit for controlling extension call is provided.

[0009]

Operation: The line state detecting section constantly monitors the use state of the telephone line by the attached telephone by detecting a change in voltage.

In this monitoring state, 1 on the main connection device side
When the extension transfer operation is performed in one terminal, the control unit of the main connection device, based on the detection signal from the line state detection unit,
Determines the line usage status of the attached telephone immediately before the extension transfer operation is performed. Then, when the telephone line is not used by the auxiliary telephone, the telephone line once captured is opened to make an extension call. That is, a calling signal is output to the called terminal, and an extension connection is established between the terminal that responded to the calling and the calling terminal.

Further, when the telephone line is being used by the side-by-side telephone, the telephone line once captured is put on hold and an extension call is made. That is, a calling signal is output to the called terminal, and an extension connection is established between the terminal that responded to the calling and the calling terminal.

After that, when the calling terminal is hooked on-hook, the called terminal is connected to the telephone line that was in the hold state, and it becomes possible to talk to an outside line.
That is, extension hold transfer becomes possible.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the electrical construction of a telephone system having the exchange function of the present invention.

In the figure, a main connection device A and an ordinary telephone (hereinafter referred to as an attached telephone) B are connected in parallel to a telephone line 1.

Further, the hook switch 2 of the main connection unit A connected to the telephone line 1 is connected with a call circuit 3 for performing 2-wire to 4-wire conversion and dial transmission operation. , The switching circuit 4 is bidirectionally connected. A handset 5, a radio circuit 6, and a call circuit 10 are bidirectionally connected to the switching circuit 4, and the call circuit 10 is connected to the extension telephone set 1 via an extension control circuit 11.
2 and bidirectionally connected.

The wireless circuit 6 is wirelessly connected to the slave 9 via the antenna 7, and the wireless circuit 6 and the wireless control circuit 8 are bidirectionally connected.

The switching circuit 4 constitutes a communication path between the telephone line 1 and the handset 5, the handset 9, and the extension telephone set 12, and an extension call between the handset 5, the handset 9, and the extension telephone set 12. It is a circuit that constitutes a path.

The call circuit 10 is a circuit for performing 2-line to 4-line conversion of a call signal between the extension telephone 12 and the handset 5 and between the extension telephone 12 and the handset 9.

The radio control circuit 8 is a circuit for controlling radio connection with the child device 9 and the like.

The extension control circuit 11 is a circuit for generating a call signal to the extension telephone 12, monitoring the line closing and opening of the extension telephone 12, and detecting a dial signal.

On the other hand, the telephone line 1 has a line state detection circuit 1 for detecting the use state of the telephone line 1 by the auxiliary telephone set B.
7 is connected, and the output of the line state detection circuit 17 is
It is guided to a main control circuit 18 that controls the operation of the entire main connection device A.

Further, the main control circuit 18 outputs the output of the handset call key 13 for calling the handset 9 and the extension telephone set 12.
And the output of the extension telephone call key 14 for calling the telephone, the main control circuit 18 sends an on / off control signal to the hook switch 2, a switching control signal to the switching circuit 4, and a speaker 16 A calling control signal is output to the calling circuit 15 connected to the respective terminals at respective timings. The main control circuit 18, the wireless control circuit 8 and the additional control circuit 11 are bidirectionally connected.

Next, the operation of the telephone system having the above-mentioned configuration will be described as follows. (1) When making a general outside line call, (2) When making an extension call when the telephone set B is on-hook, (3) Telephone set Extension hold transfer when B is off-hook (extension call transfer with external line closed)
Will be described separately.

(1) When making a general outside line call.

When making an outside line call with the handset 5, first, the hadset 5 is off-hooked. The main control circuit 18 detects the off-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to cause the handset 5 and the call circuit 3 to be connected to each other.
Form a speech path between and.

Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1.

After that, when a dial key (not shown) is operated to input the dial number of the destination, the main control circuit 1
8 detects this dial number and outputs a dial signal to the telephone line 1 through the call circuit 3.

In addition, when making an outside line call with the handset 9,
First, when the slave 9 is picked up from a charger (not shown), the slave 9 transmits an outside line capture request signal by a wireless signal. This signal is received by the antenna 7 of the main connection device A,
After being demodulated to the original outside line capture request signal in the wireless circuit 6, it is sent to the main control circuit 18 via the wireless control circuit 8.

The main control circuit 18 outputs a line connection control signal to the radio control circuit 8 based on the outside line capture request signal, and the radio control circuit 8 outputs the switching circuit 4 and the slave unit 9 based on this control signal. Wireless connection. In addition, the main control circuit 1
At 8, the switching control signal is output to the switching circuit 4 based on the outside line capture request signal to cause the wireless circuit 6 and the communication circuit 3 to be connected, and the communication path between the wireless circuit 6 and the communication circuit 3 is established. To form. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the child device 9
And telephone line 1 are connected.

Thereafter, when a dial key (not shown) of the handset 9 is operated to input a dial number of the callee, the dial request signal is transmitted from the handset 9 and is transmitted by the radio circuit 6 via the antenna 7. It is received and given to the main control circuit 18 via the wireless control circuit 8. Based on this dial request signal, the main control circuit 18 outputs a dial signal to the telephone line 1 through the call circuit 3.

When the extension telephone 12 makes an outside line call, the handset 12a of the extension telephone 12 is first off-hooked. The extension control circuit 11 detects the off-hook of the handset 12a and sends a detection signal to the main control circuit 1
Send to 8.

The main control circuit 18 uses the handset 12
Based on the detection signal indicating the off-hook of a, a switching control signal is output to the switching circuit 4 to connect the call circuit 10 and the call circuit 3, and a call path is formed between the extension telephone 12 and the call circuit 3. To do. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the extension telephone set 12 and the telephone line 1 are connected.

After that, when a dial key (not shown) is operated to input the dial number of the transmission destination, the extension control circuit 11 detects the dial signal. If the dial signal at this time is a DTMF signal, the extension control circuit 1
1 outputs the DTMF signal as it is to the telephone line 1 through the communication circuit 10, the switching circuit 4, the communication circuit 3, and the hook switch 2. If the dial signal at this time is a pulse dial signal, the extension control circuit 11 sends the detection signal to the main control circuit 18. Main control circuit 18
Receives the detection signal of the pulse dial and the call circuit 3
To the telephone line 1 from the call circuit 3 to output a dial signal.

(2) When an extension call is made when the telephone set B is on-hook. When making an extension call from the handset 5 to the cordless handset 9, first the hadset 5
Off the hook. The main control circuit 18 detects the off-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the call circuit 3 to each other, and a call path is established between the handset 5 and the call circuit 3. To form. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the handset 5 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 constantly monitors the change in the voltage of the telephone line 1, and the hook switch 2
Detects that the telephone line 1 is off-hooked by the auxiliary telephone B before the telephone line 1 is closed by turning on the telephone line 1. In this case, since the auxiliary telephone B is on-hook, it is detected that it is in the on-hook state, and the detection signal is detected.
Giving to 8. In this state, when the cordless handset call key 13 of the main connection device A is pressed and a handset handset call signal is given to the main control circuit 18, the main control circuit 18 is based on the detection signal given from the line state detection circuit 17. , Outputs an off control signal to the hook switch 2 to turn off the hook switch 2 and open the telephone line 1.

The main control circuit 18 also outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the wireless circuit 6. In addition, the main control circuit 18 is the wireless control circuit 8
Control signal is output to. Upon receiving the control signal, the wireless control circuit 8 operates the wireless circuit 6 to cause the slave unit 9 to transmit a calling signal.

The handset 5 outputs a ringing tone by receiving the ringing signal, so that the user of the handset 9 hearing the ringing tone picks up the handset 9 from the charger, and the handset 5 is released. And an extension call path is formed between the slave unit 9 and the slave unit 9 to enable extension calls.

In addition, the handset 5 to the additional telephone 12
To make an extension call to, first, the hudset 5 is off-hook. The main control circuit 18 detects the off-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the call circuit 3 to each other, and a call path is established between the handset 5 and the call circuit 3. To form.
Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the handset 5 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 detects that the auxiliary telephone set B is on-hook and therefore is in the on-hook state, and gives the detection signal to the main control circuit 18.

In this state, when the extension telephone call key 14 of the main connection unit A is pressed and the call signal of the extension telephone is given to the main control circuit 18, the main control circuit 18 is given from the line state detection circuit 17. Based on the detection signal, an off control signal is output to the hook switch 2 to turn off the hook switch 2 and open the telephone line 1.

Further, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and the handset 5 and the communication circuit 10 are connected.
And connect. Further, the main control circuit 18 outputs a control signal to the extension control circuit 11.

Upon receipt of this control signal, the extension control circuit 11 causes the extension telephone 12 to output a ringing tone, and the user of the extension telephone 12 who hears this ringing offhooks the handset 12a to extend the extension with the handset 5. An extension call path is formed between the telephone 12 and the extension call is possible.

When an extension call is made from the handset 9 to the handset 5 or the extension telephone set 12, the handset 9 is first picked up from the charger and off-hooked, and an outside line capture request signal is sent. This outside line acquisition request signal is modulated by a wireless circuit (not shown) of the child device 9 and transmitted from the antenna 9a of the child device 9. This transmitted radio wave is received by the wireless circuit 6 via the antenna 7 of the main connection unit A, demodulated into the original outside line capture request signal here, and then given to the main control circuit 18 via the wireless control circuit 8. ..

The main control circuit 18 outputs a switching control signal to the switching circuit 4 on the basis of the outside line capture request signal to cause the wireless circuit 6 and the communication circuit 3 to be connected to each other. Form a speech path between. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 based on the outside line capture request signal, and closes the telephone line 1. As a result, the cordless handset 9 and the telephone line 1 are connected via the wireless circuit 6.

On the other hand, the line state detection circuit 17 detects that the telephone set B is on-hook, so that it is in the on-hook state, and gives the detection signal to the main control circuit 18.

In this state, when a main body calling key or an additional telephone calling key (not shown) of the handset 9 is pressed, the handset 9 sends a main body calling signal or an additional telephone calling signal. When this calling signal is received by the main connection device A and sent to the main control circuit 18, the main control circuit 18 outputs an off control signal to the hook switch 2 based on the detection signal given from the line state detection circuit 17. To turn off the hook switch 2,
Open telephone line 1.

Further, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and when the transmission signal from the handset 9 is a main body calling signal, connects the radio circuit 6 and the handset 5, and the handset 5 is connected. When the transmission signal from 9 is the extension telephone calling signal, the radio circuit 6 and the communication circuit 10 are connected.
Further, the main control circuit 18 outputs a call control signal to the calling circuit 15 when the transmission signal from the slave unit 9 is the main body calling signal, and the extension control when the transmission signal from the slave unit 9 is the extension telephone calling signal. The control signal is output to the circuit 11.

As a result, the calling circuit 15 to which the calling control signal is applied drives the speaker to output the ringing tone. Further, the extension control circuit 11 to which the control signal is applied causes the extension telephone 12 to send out a ringing tone.

Then, the main connecting device A that heard this ringing tone
Or the user of the extension telephone set 12 takes off the handset 5 or the handset 12a off hook to form an extension communication path between the handset unit 9 and the handset 5 or between the handset unit 9 and the extension telephone set 12. , Extension calls are possible.

In addition, from the extension telephone 12 to the handset 5
Alternatively, when making an extension call to the handset 9, the extension telephone 12 is first hooked off. The extension control circuit 11 detects the off-hook of the extension telephone 12 and sends a signal to the main control circuit 18.

Based on this signal, the main control circuit 18 outputs a switching control signal to the switching circuit 4 to cause the call circuit 10 and the call circuit 3 to be connected to each other so that a call is made between the extension telephone 12 and the call circuit 3. Forming a path. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the extension telephone set 12 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 detects that the auxiliary telephone set B is on-hook and therefore is in the on-hook state, and gives the detection signal to the main control circuit 18.

In this state, from the extension telephone 12 to D
When calling the handset 5 by TMF, "3
Dial "0 *" and "31 *" to call the child device 9. When this dial signal is detected by the extension control circuit 11 and given to the main control circuit 18, the main control circuit 18 outputs an off control signal to the hook switch 2 based on the detection signal given from the line state detection circuit 17. Then, the hook switch 2 is turned off and the telephone line 1 is opened.

Further, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and when the dial signal from the extension telephone 12 is the main body calling signal "30 *", the call circuit 10 and the handset 5 are connected. However, when the dial signal from the extension telephone set 12 is the handset call signal "31 *", the call circuit 10 and the wireless circuit 6 are connected. Further, the main control circuit 18 outputs a call control signal to the calling circuit 15 when the dial signal from the extension telephone 12 is the main body calling signal, and wirelessly controls when the dial signal from the extension telephone 12 is the handset calling signal. The control signal is output to the circuit 8.

As a result, the calling circuit 15 to which the calling control signal is applied drives the speaker to output the ringing tone. Further, the wireless control circuit 8 to which the control signal is applied drives the wireless circuit 6 and transmits a calling signal to the slave unit 9.

Then, the main connecting device A that heard this ringing tone
Of the handset 5 or the handset 5 is off-hooked by the user of the handset 5 or the handset 9 to form an extension communication path between the extension telephone 12 and the handset 5 or between the extension telephone 12 and the handset 9. Then, the extension call becomes possible.

(3) Extension hold transfer is performed when the auxiliary telephone set B is off-hook.

In order to make an extension call from the handset 5 to the handset 9, the hadset 5 is first off-hook.
The main control circuit 18 detects the off-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the call circuit 3 to each other, and a call path is established between the handset 5 and the call circuit 3. To form. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the handset 5 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 constantly monitors the change in the voltage of the telephone line 1, and the hook switch 2
Detects that the telephone line 1 is off-hooked by the auxiliary telephone B before the telephone line 1 is closed by turning on the telephone line 1. In this case, since the auxiliary telephone B is off-hook, it is detected that it is in the off-hook state, and the detection signal is detected.
Giving to 8.

In this state, when the handset call key 13 of the main connection unit A is pressed and a handset call signal is given to the main control circuit 18, the main control circuit 18 causes the line state detection circuit 17 to operate.
Based on the detection signal given from the telephone, the telephone line 1 is kept closed without turning off the hook switch 2.

After that, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and the handset 5 and the radio circuit 6 are connected.
And connect. At this time, in the switching circuit 4, the telephone line 1
And the handset 5, the communication circuit 10, and the wireless circuit 6 are disconnected. Further, the main control circuit 18 outputs a control signal to the wireless control circuit 8.

The radio control circuit 8 receives the control signal and operates the radio circuit 6 to cause the slave unit 9 to transmit a calling signal. In the slave unit 9, a ringing tone is transmitted by receiving the ringing signal. Therefore, the user of the cordless handset 9 who hears this ringing tone picks up the cordless handset 9 from the charger, and the handset 5 and the cordless handset An extension communication path is formed between the extension communication line 9 and the extension communication line 9 so that extension communication can be performed.

After that, when the handset 5 is on-hook, the main control circuit 18 detects the on-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the radio circuit 6 and the communication circuit 3. .. At this time, since the hook switch 2 is in the off-hook state as described above, the telephone line 1 and the handset 9 are connected, and the handset 9 can make an outside call.

That is, the extension holding transfer from the handset 5 to the handset 9 is performed while holding the outside line.

In addition, the handset 5 to the additional telephone 12
To perform extension hold transfer to the
Off the hook. The main control circuit 18 detects the off-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the call circuit 3 to each other, and a call path is established between the handset 5 and the call circuit 3. To form. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the handset 5 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 detects that the telephone set B is off-hook, so that it is in the off-hook state, and gives the detection signal to the main control circuit 18.

In this state, when the extension telephone call key 14 of the main connection unit A is pressed and the extension telephone call signal is given to the main control circuit 18, the main control circuit 18 is given from the line state detection circuit 17. Based on the detection signal, the telephone line 1 is kept closed without turning off the hook switch 2.

After that, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and the handset 5 and the communication circuit 1 are connected.
Connect to 0. At this time, the switching circuit 4 disconnects the telephone line 1 from the handset 5, the communication circuit 10, and the wireless circuit 6. Further, the main control circuit 18 outputs a control signal to the extension control circuit 11.

Upon receiving this control signal, the extension control circuit 11 causes the extension telephone 12 to output a ringing tone, and the user of the extension telephone 12 who receives the ringing tone takes the handset 12a off-hook to extend the extension with the handset 5. An extension call path is formed between the telephone 12 and the extension call is possible.

After that, when the handset 5 is on-hook, the main control circuit 18 detects the on-hook of the handset 5 and outputs a switching control signal to the switching circuit 4 to connect the speech circuits 10 and 3 to each other. .. At this time, since the hook switch 2 is in the off-hook state as described above, the telephone line 1 and the extension telephone 12 are connected,
It is possible to make an outside line call using the extension telephone set 12.

That is, extension holding transfer from the handset 5 to the extension telephone set 12 is performed while holding the outside line.

When the extension hold transfer is performed from the handset 9 to the handset 5 or the extension telephone set 12, the handset 9 is first picked up from the charger and the off-hook C I and the outside line capture request signal are sent. This outside line acquisition request signal is modulated by a wireless circuit (not shown) of the child device 9 and transmitted from the antenna 9a of the child device 9. This transmitted radio wave is received by the wireless circuit 6 via the antenna 7 of the main connection unit A, demodulated into the original outside line capture request signal here, and then given to the main control circuit 18 via the wireless control circuit 8. ..

The main control circuit 18 outputs a switching control signal to the switching circuit 4 on the basis of the outside line capture request signal to connect the wireless circuit 6 and the communication circuit 3 to each other. Form a speech path between. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 based on the outside line capture request signal, and closes the telephone line 1. As a result, the cordless handset 9 and the telephone line 1 are connected via the wireless circuit 6.

On the other hand, the line state detecting circuit 17 detects that the telephone set B is off-hook, so that the off-hook state is detected, and the detection signal is given to the main control circuit 18.

In this state, when a main body calling key or an extension telephone calling key (not shown) of the handset 9 is pressed, the handset 9 sends a body calling signal or an extension telephone calling signal. When this calling signal is received by the main connection device A and sent to the main control circuit 18, the main control circuit 18 does not turn off the hook switch 2 based on the detection signal given from the line state detection circuit 17, Hold the telephone line 1 in a closed state.

Further, the main control circuit 18 outputs a switching control signal to the switching circuit 4 so that the wireless circuit 6 and the handset 5 are connected when the transmission signal from the handset 9 is the main body calling signal. When the transmission signal from the child device 9 is the extension telephone calling signal, the wireless circuit 6 and the communication circuit 10 are connected. At this time, the switching circuit 4 disconnects the telephone line 1 from the handset 5, the wireless circuit 6, and the call circuit 10.

Further, the main control circuit 18 outputs a call control signal to the calling circuit 15 when the transmission signal from the slave unit 9 is the main body calling signal, and the transmission signal from the slave unit 9 is the extension telephone calling signal. Sometimes, it outputs a control signal to the extension control circuit 11. As a result, the calling circuit 15 to which the calling control signal is applied drives the speaker to cause the ringing tone to be transmitted. Further, the extension control circuit 11 to which the control signal is applied causes the extension telephone 12 to send out a ringing tone.

Then, the main connecting device A that heard this ringing tone
Or the user of the extension telephone set 12 takes off the handset 5 or the handset 12a off hook to form an extension communication path between the handset unit 9 and the handset 5 or between the handset unit 9 and the extension telephone set 12. , Extension calls are possible.

After that, when the handset 9 is on-hook, this on-hook signal is modulated by a radio circuit (not shown) of the handset 9 and transmitted from the antenna 9a of the handset 9. This transmitted radio wave is received by the wireless circuit 6 via the antenna 7 of the main connection device A, demodulated into the original on-hook signal here, and then transmitted to the main control circuit 18 via the wireless control circuit 8.
Given to. The main control circuit 18 detects the on-hook signal from the slave unit 9 and outputs a switching control signal to the switching circuit 4 to connect the handset 5 and the communication circuit 3 or the communication circuit 10 and the communication circuit 3. Let it be done. At this time, since the hook switch 2 is in the off-hook state as described above, the telephone line 1 and the handset 5 or the telephone line 1
And the extension telephone set 12 are connected to each other, and an outside line call can be made by the handset 5 or the extension telephone set 12.

That is, extension holding transfer is performed from the handset 9 to the handset 5 or the extension telephone 12 while holding the outside line.

In addition, from the extension telephone 12 to the handset 5
Alternatively, when performing extension hold transfer to the slave 9, the extension telephone 12 is first hooked off. The extension control circuit 11 detects the off-hook of the extension telephone 12 and sends a signal to the main control circuit 18.

Based on this signal, the main control circuit 18 outputs a switching control signal to the switching circuit 4 to connect the call circuit 10 and the call circuit 3 and call between the extension telephone 12 and the call circuit 3. Forming a path. Further, the main control circuit 18 outputs an ON control signal to the hook switch 2 to turn ON the hook switch 2 and close the telephone line 1. As a result, the extension telephone set 12 and the telephone line 1 are connected.

On the other hand, the line state detection circuit 17 detects that the auxiliary telephone set B is off-hook, and therefore, the line state detection circuit 17 gives the detection signal to the main control circuit 18.

In this state, the additional telephone 12 to D
When calling Hadset 5 by TMF, select "3.
Dial "0 *" and "31 *" to call the child device 9. When this dial signal is detected by the extension control circuit 11 and given to the main control circuit 18, the main control circuit 18 does not turn off the hook switch 2 based on the detection signal given from the line state detection circuit 17,
Hold the telephone line 1 in a closed state.

Further, the main control circuit 18 outputs a switching control signal to the switching circuit 4, and when the dial signal from the extension telephone set 12 is the main body calling signal "30 *", the call circuit 10 and the handset 5 are connected. However, when the dial signal from the extension telephone set 12 is the handset call signal "31 *", the call circuit 10 and the wireless circuit 6 are connected. At this time,
The switching circuit 4 disconnects the telephone line 1 from the handset 5, the wireless circuit 6, and the call circuit 10. Also,
The main control circuit 18 outputs a call control signal to the calling circuit 15 when the dial signal from the extension telephone 12 is the main body call signal, and when the dial signal from the extension telephone 12 is the handset call signal, the radio control circuit 8 Control signal is output to.

As a result, the calling circuit 15 to which the calling control signal is applied drives the speaker to send the calling sound. Further, the wireless control circuit 8 to which the control signal is applied drives the wireless circuit 6 and transmits a calling signal to the slave unit 9.

Then, the main connecting device A that heard this ringing tone
Of the handset 5 or the handset 5 is off-hooked by the user of the handset 5 or the handset 9 to form an extension communication path between the extension telephone 12 and the handset 5 or between the extension telephone 12 and the handset 9. Then, the extension call becomes possible.

Thereafter, the handset 1 of the extension telephone set 12
When 2a is on-hook, the main control circuit 18 detects this on-hook and outputs a switching control signal to the switching circuit 4,
The handset 5 is connected to the communication circuit 3 or the wireless circuit 6 is connected to the communication circuit 3. At this time, since the hook switch 2 is in the off-hook state as described above, the telephone line 1 and the handset 5 or the telephone line 1 and the handset 9 are connected to each other, and the outside call by the handset 5 or the handset 9 becomes possible. ..

That is, extension holding transfer is performed from the extension telephone set 12 to the handset 5 or the handset 9 while holding the outside line.

As described above, in the telephone system having the exchange function of the present invention, the line state detection circuit 17 detects whether the telephone set B is off-hook immediately before the hook switch 2 is closed. When an extension calling operation is performed, the main control circuit 18 determines, based on the detection result of the line state detection circuit 17, whether the extension call is an extension call with the telephone line 1 opened or the extension hold transfer with the telephone line 1 held. It is like this.

In the above embodiment, the number of telephone lines is one, and the telephone set B connected to this telephone line 1 is one.
Although a telephone system is used in which the number of telephones is one and each of the slave 9 and the additional telephone 12 connected to the main connection device A is one, the number of telephone lines is not limited to one. Further, the numbers of the auxiliary telephone set B, the child device 9 and the additional telephone device 12 are not limited to one, and it is possible to have a system configuration in which a plurality of them are provided, and either the child device 9 or the additional telephone device 12 can be used. It is also possible to have a system configuration that has been lost.

[0093]

In the telephone system having the exchange function of the present invention, the line state detection unit detects whether or not the attached telephone is off-hook immediately before the hook switch is closed, and the extension call operation is performed. In this case, the control unit is configured to determine, based on the detection result of the line state detection unit, whether the extension call is an extension call with the telephone line opened or the extension hold transfer with the telephone line held. When an on-site telephone is on a call and one terminal connected to the main connection device is off-hook and this call is turned from this terminal to another terminal, the extension is surely held without disconnecting the outside line. This has the effect of enabling transfer.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a telephone system having a switching function of the present invention.

[Explanation of symbols]

 1 Telephone line 9 Handset 12 Extension telephone 18 Main control circuit A Main connection device B Side telephone

Claims (1)

Claims: What is claimed is: 1. A telephone system in which a main connection device having a plurality of terminals and capable of extension transfer and at least one or more side-mounted telephones are connected in parallel to a telephone line. In the connection device, a line state detection unit that detects the use state of the telephone line by the auxiliary telephone set, and during the extension transfer operation on the main connection unit side, the line state detection unit confirms that the telephone line is not used. When it is detected, the once captured telephone line is opened to make an extension call, and when the line state detection unit detects that the telephone line is in use, the once captured telephone line is put on hold and an extension call is made. A telephone system having an exchange function, comprising: