JPH06141084A - Private branch exchange - Google Patents

Abstract

PURPOSE:To provide a private branch exchange capable of enabling response for an incoming call at an extension terminal during conference communication and making a call originating source connected by the response for the incoming call participate in the conference communication. CONSTITUTION:When the incoming call to an extension telephone set during the conference communication is detected, LCD display and tone signal transmission for reporting the incoming call at the extension telephone set as a call incoming destination are performed by an incoming call display control means 21. Then, when a conference holding request and an incoming call response request are performed by a speaker on an incoming call side who receives the report. The extension telephone set is tentatively separated from the conference communication and is connected to the call originating source by a conference holding control means 22 and an incoming call response control means 23. When a re-entry request to the conference communication is performed from the extension telephone set on the incoming call side in this state, a conference addition control means 24 lets the above-mentioned extension telephone set and its communicating party participate in the conference communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a private branch exchange having a function of inviting a plurality of other extensions or outside lines from a specific extension terminal to form a conference call.

[0002]

2. Description of the Related Art Conventionally, in a private branch exchange, there is a service in which a speaker of another extension line or an outside line (station line, leased line) is called from a specific extension terminal to make a so-called conference call of three or more parties. It's being used. In general, an extension or an outside line called for a conference call is called a slave station, and a specific extension for calling a slave station is called a master station.

By the way, the calling of the slave station for making a conference call is generally performed in the following procedure. That is, the speaker of the master station, who is the conference organizer, first presses the [meeting button] on the master station terminal while talking to the first slave station.
push. Then, the private branch exchange sends a hold tone to the first slave station and a dial tone to the master station. In this state, the master station speaker is second
When the telephone number of the child station is dialed, the exchange starts calling the second child station based on the dialed telephone number. Then, when the second mobile station responds to this call, the exchange connects the second mobile station and the master station to establish a call state. The talker of the master station pushes the conference button again when a call is established between the talker and the second slave station. Then, the exchange connects the master station with each of the first and second slave stations to establish a three-party conference call state.

Next, it is assumed that the parent station pushes the conference button again to make a call between the four parties. Then, the parent station leaves the three-way conference call and receives the dial tone sent from the exchange. At this time, a communication state is established between the first slave station and the second slave station. In this state, when the speaker of the master station dials the telephone number of the third slave station, the exchange starts calling the third slave station based on the dialed telephone number. When the third slave station responds to this call, the exchange connects the third slave station and the master station to establish a call state. The talker of the master station presses the conference button again when the communication with the third slave station is established. Then, the exchange connects the master station with each of the first, second and third slave stations to establish a four-party conference call state. Similarly thereafter, the parent station can sequentially join the child stations in the conference call until the number of participating stations allowed by the system is reached.

[0005]

However, in the conventional private branch exchange equipped with such a conference call function, all incoming calls to extension telephones during a conference call are treated as "busy" and rejected. . For this reason, it was not possible to call the extension telephone during the conference call from another extension telephone.

Although the extension telephone called by the master station can participate in the conference call as described above, it cannot respond to an incoming call to the extension telephone in the conference and join the conference call. There wasn't.

The present invention has been made in consideration of the above circumstances. An object of the present invention is to enable an incoming call response at an extension terminal during a conference call and to identify a calling source connected by this incoming call response. It is to provide a private branch exchange capable of participating in a conference call.

[0008]

In order to achieve the above object, the present invention accommodates a plurality of extensions, each of which is connected to an extension terminal at its end, and selectively selects the extension terminal according to a predetermined extension calling operation. In a private branch exchange equipped with a conference call function that enables a conference call by connecting to a common circuit for conference call, when a call is received to an extension terminal connected to the common circuit for conference call by the conference call function, An incoming call display control means for causing the extension terminal to display that the own terminal is receiving a call, and an extension terminal for displaying that the own terminal is receiving a call by the incoming call display control means. When a predetermined conference hold request is sent from the conference terminal, the conference hold control means for putting the extension terminal in the hold state in the common circuit, and the conference hold control means for holding in the common circuit When a predetermined incoming call response request is sent from the extension terminal in the active state, the incoming call response control means for connecting between the extension terminal and the calling source, and the incoming call response control means is in a call with the calling source. And a conference addition control means for selectively connecting the extension terminal and the call destination to the common circuit when a predetermined conference re-input request is sent from the extension terminal.

[0009]

As a result, according to the present invention, the incoming call display control means can notify the speaker who is in the conference call of the occurrence of the incoming call, and the speaker who receives the notification requests the conference hold request from the extension terminal. Is input, the extension terminal is temporarily disconnected from the common circuit for conference call and put in a hold state. Then, when an incoming call response request is input by the speaker in this state, the extension terminal in the hold state and the caller are connected to establish a two-party call state.
Therefore, a speaker during a conference call can leave the conference call and respond to the incoming call when the incoming call arrives.

Further, when a conference holding release request is sent from the extension terminal by the speaker who is answering the incoming call, the extension terminal is released from the hold state and connected to the common circuit, and the call destination is also the above. Connected to a common circuit. Therefore, the speaker who is answering the incoming call can join the calling party together with the calling terminal after the call ends.

[0011]

1 is a circuit block diagram showing the configuration of a private branch exchange according to an embodiment of the present invention. In the figure,
This private branch exchange includes a switching circuit 1, a control circuit 2, a storage circuit 3, extension circuits LC1 to LCn, and a station line circuit TRK1.
.About.TRKm, and a control data bus line 4 for transmitting various control signals between these circuits and the control circuit 2. A maintenance terminal 5 is connected to the control circuit 2 via a control data bus line 4.

Each of the extension circuits LC1 to LCn has an extension L1.
To Ln are connected to extension telephones EKT1 to EKTn, and office lines SL1 to SLm are connected to office line circuits TRK1 to TRKm, respectively. Extension circuit LC
1 to LCn and station line circuits TRK1 to TRKm are connected to the extension lines L1 to Ln and the station line S, respectively.
While monitoring the states of L1 to SLm, control information is exchanged with the control circuit 2 to perform predetermined line control.

Under the control of the control circuit 2, the exchange circuit 1 includes the extension circuits LC1 to LCn and the station line circuits TRK1 to TRK.
Km is exchange-connected with each other, and the extension circuits LC1 to LCn are exchange-connected with each other. Further, the exchange circuit 1 is controlled by the control circuit 2 so that the extension L1
.. Ln, station lines SL1 to SLm, and a private line (not shown) form a communication path for conducting a conference call.

The extension telephones EKT1 to EKTn are, for example, as shown in FIG. 2, a telephone body 11, a handset 12, a hook mechanism 13, a dial key group 14, and a function key group 1.
5 and a liquid crystal display (LCD) 16 for displaying various information such as the telephone number of the callee and the call charge.

The control circuit 2 is provided with, for example, a microcomputer as a main control unit, and in addition to ordinary control means such as exchange control for incoming and outgoing calls, an incoming call display control means 21 and a conference hold control means 22. , Incoming call response control means 2
3 and conference addition control means 24.

The incoming call display control means 21 determines whether or not the called extension telephone is in the conference call state when an incoming call occurs, and if it is in the conference call state, the conference call is made by the LCD display and tone signal transmission on the extension telephone. This is to notify the inside speaker of the occurrence of an incoming call.

The conference hold control means 22 receives a conference hold request by the hold key operation on the extension telephone which has been informed by the incoming call display control means 21 that an incoming call has occurred. It is determined whether or not the hold is possible. If the conference can be held, the extension telephone is put on hold for the conference call and the LCD of the extension telephone displays the fact that the conference is on hold.

The incoming call response control means 23 is placed in the hold state when the incoming call response request by the operation of the function key arrives from the extension telephone set in the hold state for the conference call by the conference hold control means 22. It is determined whether or not there is an incoming call to the telephone, and if there is an incoming call, the extension telephone in the hold state and the caller are connected to establish a two-party call state and The LCD of the extension telephone displays that the conference is on hold and that a two-party call is in progress.

The conference addition control means 24 re-enters the conference call when the re-entry request by the operation of the function key arrives from the extension telephone of the receiving side which has been made into the two-party call state by the incoming call response control means 23. It is judged whether or not it is possible, and if possible, only the extension telephone on the receiving side based on the re-entry request,
Alternatively, the extension telephone of the calling side is made to participate in the conference call together with the extension telephone of the receiving side.

Next, the operation of the private branch exchange configured as described above will be described with reference to the flow charts shown in FIGS. The control circuit 2 of the private branch exchange monitors the occurrence of inter-extension transmission in a steady state. Then, when the occurrence of a call originating from any extension telephone is detected in step 4a of FIG. 4, the state of the extension corresponding to the extension number of the called party sent from this extension telephone is read (step 4b), and the read state is used as a basis. In step 4c, it is determined whether the extension telephone of the called party is in a conference call. As a result, if the extension telephone of the called party is not in a conference call and is in an idle state, for example, the control circuit 2 performs a normal incoming call process in step 4i.

On the other hand, when it is determined that the extension telephone of the called party is in a conference call, the control circuit 2 controls the extension telephone in the conference call to send a short tone (step S1). 4d), control for transmitting a ring back tone (R.B.T.) to the extension telephone on the calling side is performed (step 4e). As a result, the speaker on the receiving side in the conference call is notified that there is an incoming call, and the speaker on the calling side is notified that the called party is being called.

Then, the control circuit 2 determines in step 4f whether or not the extension telephone as the destination is the conference host terminal (master station). As a result, when it is determined that the extension telephone of the call destination is the conference host terminal, the control circuit 2 sends the call to the extension telephone of the call destination in step 4g of FIG.
The LCD display shown in is displayed. Also, the above step 4
As a result of the determination by f, if the extension telephone of the call destination is the conference participant terminal (slave station), the control circuit 2 sends the call to the extension telephone of the call destination at L shown in FIG.
Have the CD displayed. In addition, "50" in FIG.
The display of "00" represents the extension number of the last added member, and the display of "4000" in FIG. 3B represents the host telephone number.

In this state, it is assumed that the speaker of the extension telephone of the called party makes a conference hold request. This request is made, for example, by pressing the hold key on the telephone. When the control circuit 2 detects a conference hold request from the extension telephone during the conference call in step 5a of FIG. 5, it determines in step 5b whether the conference can be held. If the result of this determination is that conference hold is not possible, the control circuit 2 keeps the extension telephone for which the hold request is made in step 5f in the conference call state. On the other hand, if the conference can be put on hold, the control circuit 2 puts the extension telephone for which the hold request has been made into the holding state (step 5c), whereby only the extension telephone is temporarily disconnected from the conference call and another conference is held. The conference call by the members is continued (step 5d). Subsequently, the control circuit 2 causes the LCD of the extension telephone set in the hold state in step 5e to display "KAIGI HORYU" and re-displays the extension number of the called party.

In this state, it is assumed that the conference-holding speaker makes an incoming call response request to answer the incoming call. This request is made, for example, by pressing a predetermined function key on the telephone. When the control circuit 2 detects an incoming call response request from the extension telephone set in the conference hold mode in step 6a of FIG. 6, it determines in step 6b whether an incoming call still exists. If the result of this determination is that the incoming call has already been recovered, the control circuit 2 causes the LCD of the extension telephone set in the conference hold to display a message indicating that there is no incoming call in step 6e. If an incoming call is present, the control circuit 2 connects the caller extension telephone and the conference-holding extension telephone in step 6c to establish a two-party call state, and in step 6d, the extension of the called party. On the LCD of the telephone, it is displayed that the conference is still on hold and that the two-party call is in progress.

After shifting the extension telephone in the conference call state to the two-party call state in this way, the control circuit 2 monitors the conference re-entry request from the extension telephone on the receiving side. When such a request is detected in step 7a of FIG. 7, it is determined in step 7b whether reentry is possible. If the result of this determination is that re-entry is not possible, the control circuit 2 proceeds to step 7
Continue the two-party call state with j. On the other hand, if reentry is possible, the control circuit 2 determines in step 7c whether only the original conference member is reentrant or the callee (extension side telephone set of the calling party) is reentrant. This determination is made based on the designation made when the conference re-entry request is made. As a result of this determination, if only the original conference member is re-entered, the control circuit 2 releases the hold of the extension telephone on the receiving side to participate in the conference call in step 7d, and disconnects the callee in step 7e. . At this time, a restriction sound is sent to the extension telephone of the called party that has been disconnected.

On the other hand, as a result of the judgment in the above step 7c, if the re-entry also includes the callee, the control circuit 2 judges in step 7f whether or not the conference circuit is available. If the result of this determination is that there is no vacancy in the conference circuit, the control circuit 2 shifts to step 7d, in which only the extension telephone on the receiving side is re-entered and the callee is disconnected in step 7e. If the conference circuit has a vacancy as a result of the determination in step 7f, the control circuit 2 captures one conference circuit for one person in step 7g, and then first causes the extension telephone on the receiving side to participate in the conference call in step 7h. Then, in step 7h, the calling extension telephone, which is the other party of the call, participates in the conference call using the conference circuit captured as described above.

As described above, according to the present embodiment, when an incoming call to the extension telephone set during a conference call is detected, the LCD display and tone signal transmission of the extension telephone set cause the speaker in the conference call to receive the incoming call. Let me know
When the speaker who receives this notification makes a conference hold request and an incoming call response request following this request, the extension telephone is temporarily disconnected from the conference call and placed in the hold state. Since the extension telephone and the extension telephone of the caller are connected to form a two-party call state, the problem that the call to the extension telephone during a conference call is rejected as in the conventional case is prevented, As a result, it becomes possible to call the extension telephone in the conference call from another extension telephone to make a call.

Further, when a conference re-entry request is sent from an extension telephone set in a two-party call state after leaving the conference call once, not only the extension telephone which is holding the conference call but also the calling party Since the extension telephone is also made to participate in the conference call, it is possible to provide a private branch exchange having a higher serviceability as compared with the conventional case in which the parent station must call all the child stations.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the conference hold request and the incoming call response request in the extension telephone during the conference call and the conference re-entry request in the two-party call state are performed by the hold key and the predetermined function key. It may be performed by a set special number or the like. Other,
Various modifications can be implemented without departing from the scope of the present invention.

[0030]

As described in detail above, according to the present invention, a conference hold request and an incoming call response request are made from an extension terminal during a conference call in which an indication that an incoming call has arrived is displayed. In this case, the extension terminal and the caller are connected, and when the extension terminal in this state requests re-entry to enter the conference call, the extension terminal and the call destination are conference-called. Since it is connected to a common circuit for use in a conference call, it is possible to provide an incoming call response to an extension terminal during a conference call, and to provide a private branch exchange capable of causing a caller connected by this incoming call response to participate in the conference call. be able to.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a schematic configuration of a private branch exchange according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an extension telephone.

FIG. 3 is a diagram showing an LCD display example of an extension telephone when an incoming call occurs.

4 is a flowchart showing a control procedure and control contents of the control circuit shown in FIG.

5 is a flowchart showing a control procedure and control contents of the control circuit shown in FIG.

6 is a flowchart showing a control procedure and control contents of the control circuit shown in FIG.

7 is a flowchart showing a control procedure and control contents of the control circuit shown in FIG.

[Explanation of symbols]

1 ... Exchange circuit, 2 ... Central control circuit, 3 ... Storage circuit, 4 ...
Control data bus line, 11 ... Telephone body, 12 ... Handset, 13 ... Hook mechanism, 14 ... Dial key group, 15
... selection key group, 16 ... liquid crystal display (LCD), 21 ... incoming call display control means, 22 ... conference hold control means, 23 ... incoming call response control means, 24 ... conference addition control means, EKT1 to EKT
KTn ... extension telephone, L1-Ln ... extension, SL1-SL
m ... station line, LC1 to LCn ... extension circuit, TRK1 to TR
Km ... Station line circuit.

Claims (1)

[Claims] 1. A conference call is made by accommodating a plurality of extensions, each of which is connected to an extension terminal at a terminal end, and selectively connecting the extension terminals to a common circuit for conference calls according to a predetermined extension call operation. In a private branch exchange having a conference call function that enables the call, when an incoming call is made to an extension terminal connected to the common circuit by the conference call function, a display indicating that the own terminal is receiving the call at the extension terminal is displayed. When a predetermined conference hold request is sent from the incoming call display control means for causing the incoming call display control means and the internal terminal displaying the fact that the incoming call is being received by the incoming call display control means, A conference hold control means for putting the common circuit in the hold state, and when a predetermined incoming call response request is sent from the extension terminal in the hold state to the common circuit by the conference hold control means, Incoming call response control means for connecting between the extension terminal and the call originator, and when a predetermined conference reentry request is sent from the call originator and the extension terminal in a call by this incoming call response control means, A private branch exchange, comprising: a conference addition control means for selectively connecting the extension terminal and the call destination thereof to the common circuit.