JPH0637908A - Private branch exchange - Google Patents

Abstract

PURPOSE:To provide a private branch exchange in which the calling of slave stations can be easily attained without conference sponsor's interrupting conference speech, and the conference can forcively exclude an arbitrary slave station from the conference speech by. CONSTITUTION:A storage circuit 3 is equipped with a memory table in which the extension number of the slave station is stored corresponding to each selection key provided on each extension telephone set, and the memory table in which the communicating state of each housed extension is stored. Then, when the selection key corresponding to the slave station in an empty state is pressed in a master station in a speech or the conference speech, the pertinent slave station is called, and allowed to participate in the conference speech by a conference speech control means 21. On the other hand, when the selection key corresponding to the slave station in an already participating state is pressed in the master station in the conference speech, the pertinent slave station is allowed to leave the conference speech.

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 and the first and second slave stations to each other 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 and the first, second, and third slave stations to each other 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]

As described above, in the conventional conference call, the master station once leaves the conference call and calls the slave station every time it convenes the slave station, and waits for the response from the slave station. And return to the meeting. However, the frequent absence of the parent station, which is the organizer of the conference, may delay the progress of the conference, and the parent station has a problem that the above-mentioned series of operations required for convening the child stations is troublesome. there were.

On the other hand, when an arbitrary slave station is to be taken out of the conference during a conference call, the master station has no other choice but to urge the slave station to put a handset, and the master station actively activates. It is not possible to remove a specific slave station from the conference. Generally, there is a chairman in the meeting to control the progress, but in the conference by telephone, as described above, it is necessary to leave the meeting each time the parent station that is the chairman adds a child station, and force the meeting participants from the meeting. Since it cannot be removed, there was a problem that the parent station could not take control of the conference.

Therefore, an object of the present invention is to allow a conference organizer to easily call a slave station without leaving the conference call, and for the conference organizer to forcibly remove any slave station from the conference call. It is to provide a private branch exchange capable of

[0008]

In order to achieve the above object, the present invention is directed to a plurality of extension terminals each having at least one extension calling function key provided in correspondence with a desired extension and connected to each extension. In a private branch exchange having a conference call function that enables a conference call by selectively connecting the plurality of extension terminals to a common circuit for conference calls, for storing information indicating the call state for each extension. When the operation information of the extension call function key is sent from the call information storage means of the above and the extension terminal during a call, the call state of the extension corresponding to the operated extension call function key is stored in the call state storage means. And a conference call control unit for making a determination based on the information stored in. If the conference call control means determines that the extension corresponding to the operated extension call function key is idle by the call state determination means, the extension is called to connect to the common circuit. On the other hand, when it is determined that the extension corresponding to the operated extension calling function key is in a conference call, the extension is disconnected from the common circuit.

[0009]

As a result, according to the present invention, the call state determining means operates the one extension terminal during a two-party call or the master station (a specific extension terminal that convenes a slave station) during a conference call. If it is determined that the extension corresponding to the extension calling function key is idle, the extension is called based on the information stored in the call state storage means, and a response to the call is given. When made, this extension is automatically connected to the common circuit for conference call to which the extension terminal of the calling source is connected. Therefore, the master station, which is the organizer of the conference, does not have to leave the conference each time the slave station is convened, and the simple operation of operating the function key to which the desired slave station is assigned while continuing the call It is possible to call a station.

Further, when it is determined by the call state determining means that the extension corresponding to the extension calling function key operated in the master station during the conference call is already participating in the conference call including the master station. Is disconnected from the conference call by disconnecting the extension from the connected common circuit for the conference call. Therefore, the parent station serving as the conference organizer can forcibly remove any child station from the conference call whenever necessary according to the progress of the conference.

[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 (SW) 1, a central control circuit (CC) 2, a memory circuit (MEM) 3, and an extension circuit LC.
1 to LCn, station line circuits TRK1 to TRKm, and a control data bus line 4 for transmitting various control signals between these circuits and the central control circuit 2.

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 central control circuit 2 to perform predetermined line control.

Under the control of the central control circuit 2, the exchange circuit 1 includes the extension circuits LC1 to LCn and the station line circuits TRK1 to TRK1.
Switching connection with the TRKm is performed, and switching connection with the extension circuits LC1 to LCn is performed. Under the control of the control circuit 2, the exchange circuit 1 forms a communication path for conducting a conference call between the extension lines L1 to Ln, the office lines SL1 to SLm, and a dedicated line (not shown).

The extension telephones EKT1 to EKTn are, for example, as shown in FIG. 2, a telephone body 10, a handset 11, a hook mechanism 12, a dial key group 13, and a selection key group 1.
4 and LEs provided corresponding to these selection keys
And an indicator lamp 15 such as D. The above selection key is used to call a slave station when a conference call is held,
It is used for disconnecting a slave station during a conference call. Further, key addresses KA1 to KAj for identifying the selection keys are assigned to the selection keys in advance. The indicator lamp 15 displays various states under the control of the control circuit 2 described later.

The storage circuit 3 has a slave station registration table 31 and a communication state determination table 32, as shown in FIGS. 3 (a) and 3 (b), respectively. Slave registration table 31
Is prepared for each of the extensions L1 to Ln and stores the extension numbers of the other extension telephones corresponding to the key addresses KA1 to KAj of the selection keys provided on the extension telephones. This registration is performed from, for example, a maintenance terminal (not shown). The communication state determination table 32 is
A flag indicating the communication state is stored for each extension number (DN) given to each of the extension lines L1 to Ln to be accommodated, and the contents thereof are rewritten successively under the control of the control circuit 2. That is, the flag "0" indicating that the extension is in the idle state is registered, and the flag "2" is registered for the extension in the busy state with other extensions.
Further, the flag "1" is registered for the extension being called by the conference call request, and the flag "3" is registered in the storage area for the extension which is participating in the conference.

The central control circuit 2 is provided with, for example, a microcomputer as a main control section, and is provided with conference call control means 21 in addition to ordinary control means such as exchange control relating to incoming and outgoing calls. This conference call control means 21
When any selection key is pressed on one extension telephone during a two-party call or on the extension telephone of the master station during a conference call with three or more parties, the communication state of the extension corresponding to this selection key After making a judgment based on the stored contents of the judgment table 32, a predetermined process is executed according to the judgment result. Examples of this type of processing include calling processing when the extension selected by the selection key is in an idle state, disconnection processing when the selected extension is already in a conference call state, and the selected extension is There is a call cancellation process when the call is being made by the selection key. When the selected extension is busy with another extension, pressing the selection key itself is invalidated.

Further, the conference call control means 21 disconnects the child station from the conference call when the child station participating in the conference ends the call, and stores it in the storage area corresponding to the child station in the communication state discrimination table 32. The control for writing the flag "1" indicating "vacant" is performed.

In addition, the conference call control means 21 constantly monitors the state of each of the extensions L1 to Ln accommodated therein, performs control for writing a flag indicating the state in the communication state determination table 32, and at the same time, controls them. The lighting pattern of each indicator lamp 15 in the conference convening terminal (master station) is changed according to the state, and control is performed to constantly inform the convener of the communication state of the registered slave station.

Next, the operation of the private branch exchange configured as described above will be described. First, the procedure for convening a child station will be described. For example, in a state where the speaker of the extension telephone EKT1 and the speaker of the extension telephone EKT2, which is the first slave station, are talking with each other, the speaker of the extension telephone EKT1 calls the extension of the second slave station to request a call. It is assumed that the selection key on the telephone EKT1 is pressed. At this time, the speaker of the extension telephone EKT1 selects the selection key corresponding to the desired slave station, that is, the second slave station from the plurality of selection keys, and the indicator lamp 15 corresponding to the selection key indicates the idle state. Confirm that the message is to the effect, and then press it. Then, this pressing information is detected by the extension circuit LC1 via the extension L1,
Further, the port number of the extension L1 and the key address of the pressed selection key are sent from the extension circuit LC1 to the control circuit 2 via the control data bus line 4.

When the control circuit 2 detects that the selection key of the extension telephone EKT1 is pressed in step 401 of FIG. 4, it checks the slave station registration table 31 provided in correspondence with the extension L1 in step 402, thereby The DN registered corresponding to the pressed selection key is read, and the state of the extension corresponding to the read DN is checked in step 403 based on the stored contents of the communication state determination table 32. As a result, when it is determined that the extension corresponding to the pressed selection key is in an empty state, the control circuit 2 determines that the selection key is pressed to call a slave station having the extension telephone EKT1 as a master station. Then, the process proceeds to step 404.

In step 404, it is judged whether or not the number of conference participating stations at the present time has reached a predetermined value x (x is a natural number) allowed by the system. As a result, when it is determined that the number of conference participants including the second slave station is less than the predetermined value x, the control circuit 2 causes the second slave station requested to be called to participate in the conference call. Initiate a call to this second slave station. That is, the control circuit 2 proceeds to step 405.
Instructing the extension circuit to which the second slave station is connected to transmit a calling signal, and in step 406, the DN of the second slave station in the communication state determination table 32 is transmitted.
The flag "1" which means "calling" is written in the storage area corresponding to. At the same time, the control circuit 2 generates an indicator lamp display control signal for making the indicator lamp 15 corresponding to the pressed selection key in the extension telephone EKT1 a lighting pattern indicating "calling" in step 407. , And sends it to the extension telephone EKT1. Then, a call signal is sent to the second slave station to call the speaker, and the extension telephone EKT1 displays the indicator lamp 15 corresponding to the pressed selection key during the call. . At this time, the call between the extensions L1 and L2 is still held.

In this state, it is assumed that a response is made by the speaker at the second slave station. When the control circuit 2 detects in step 408 that the second slave station has responded, the control circuit 2 stops sending the ringing signal, and in step 409, the second slave station makes a call to the extension telephones EKT1 and EKT2. It controls the call path to make a three-party conference call by joining the station. Further, the control circuit 2 rewrites the storage area corresponding to the DN of the second slave station in the communication state discrimination table 32 to the flag "3" which means "response" in step 410, and in step 411 the extension telephone EKT1. The indicator lamp display control signal for making the indicator lamp 15 of the selection key corresponding to the second slave station in the above "response" display is generated and sent to the extension telephone EKT1. Then, the extension telephone E
In KT1, the indicator lamp 15 corresponding to the pressed selection key has a lighting pattern indicating a response state,
The master station speaker is informed of the response.

Thereafter, the control circuit 2 repeats the above series of processing each time a request for convening a slave station arrives from the master station. However, when the number of conference participating stations has reached the predetermined value x by the determination in step 4d, the pressing of the selection key at this time is invalidated and the above process is not executed. In addition, during the period from the call of the slave station to the response thereof, the master station is always kept in the call state.

Next, a procedure for removing an arbitrary slave station participating in a conference call from the conference will be described. It is assumed that the speaker of the extension telephone EKT1 as the convener of the conference presses the selection key corresponding to the second slave station during the conference call in order to remove the second slave station from the conference. The slave station participating in the conference can be identified by the display of the indicator lamp 15 on the master station terminal, and the master station speaker wants to remove it from the selection keys indicating that the display of the indicator lamp 15 is “answer”. Select a slave station and press it. This pressed information is detected by the extension circuit LC1 via the extension L1, and the extension circuit L is further detected.
The port number of the extension L1 and the key address of the pressed selection key are sent from C1 to the control circuit 2 via the control data bus line 4. When the control circuit 2 detects the pressing of the selection key in the extension telephone EKT1 in step 401 of FIG. 4 as described above, it reads the DN corresponding to the pressed selection key in step 402, and also reads this in step 403. The state of the extension corresponding to DN is checked based on the stored contents of the communication state discrimination table 32.
As a result, when it is determined that the extension corresponding to the pressed selection key is an extension that is already participating in (answering) a conference call, the control circuit 2 presses the selection key to disconnect the slave station. Then, the process proceeds to step 412.

The control circuit 2 proceeds to step 212 to execute the second
Control for disconnecting only the slave station from the conference call, and an instruction to send a predetermined restriction sound to the extension circuit to which the second slave station is connected. Then, the second slave station is removed from the conference call and receives the restriction sound from the exchange. At this time, the call is held between the master station and the remaining slave stations. Then control circuit 2
"Busy" the storage area corresponding to the DN of the second slave station in the communication state determination table 32 in step 413.
Is rewritten to the flag "2" meaning "," and at step 414, the indicator lamp display control signal for changing the display of the indicator lamp 15 corresponding to the second slave station in the extension telephone EKT1 to the lighting pattern indicating "busy". Is generated and sent to the extension telephone EKT1. In the extension telephone EKT1 which receives this control signal, the indicator lamp 15 of the pressed selection key is displayed as a ringing indication.

Thereafter, when the control circuit 2 detects in step 415 that the second slave station is on-hook,
In step 416, the storage area corresponding to the DN of the second slave station in the communication status determination table 32 is rewritten to the flag "0" which means the "empty" status, and in step 417 the second child in the extension telephone EKT1. An indicator lamp display control signal for setting the indicator lamp 15 corresponding to the station to a lighting pattern indicating "empty" is generated and sent to the extension telephone EKT1. As a result, in the extension telephone EKT1, the indicator lamp 15 of the pressed selection key is displayed as an empty display.

Next, the case of canceling the call of the slave station will be described. Extension telephone EK, the meeting convener
It is assumed that the speaker of T1 presses the selection key corresponding to the third slave station in order to cancel the call while the third slave station is calling. In this case, the master station speaker depresses the indicator lamp 15 corresponding to the selection key while the display pattern is "lighting". Then, this pressing information is transmitted to the extension circuit LC via the extension L1.
1, the port number of the extension L1 and the key address of the pressed selection key are sent from the extension circuit LC1 to the control circuit 2 via the control data bus line 4. When the control circuit 2 detects the pressing of the selection key in the extension telephone EKT1 in step 401 of FIG. 4 as described above, it reads the DN corresponding to the pressed selection key in step 402, and also reads this in step 403. The state of the extension corresponding to DN is checked based on the stored contents of the communication state discrimination table 32. As a result, when it is determined that the extension corresponding to the pressed selection key is calling for the conference call, the control circuit 2 determines that the pressing of the selection key is a call cancellation request, and step 418 Move to.

The control circuit 2 proceeds to step 418 to execute the third
To the extension circuit to which the slave station is connected, to stop the sending of the calling signal. Then, the call at the third slave station is stopped. Subsequently, the control circuit 2 determines in step 419 the communication state determination table 32
In step 420, the storage area corresponding to the DN of the third slave station is rewritten to a flag "0" indicating "empty", and in step 420, the indicator lamp 15 corresponding to the third slave station in the extension telephone EKT1 is "empty". An indicator lamp display control signal for producing a lighting pattern indicating is generated and sent to the extension telephone EKT1. In the extension telephone EKT1 which receives the display control signal, the indicator lamp 15 of the pressed selection key is displayed as an empty display.

The control circuit 2 uses the slave station registration table 31.
If there is a busy busy extension, the indicator light 15 of the selection key on the master station terminal corresponding to the busy extension is set to the "busy" display. The caller is notified that the call cannot be made.
When the speaker presses the selection key on the extension telephone EKT1 indicating "busy" (detected in steps 401 to 403), the control circuit 2 presses the selection key. Reject the convocation request of the slave station as invalid.

Next, a description will be given of processing when an arbitrary child station participating in a conference call ends the call. Now, for example, it is assumed that the speaker of the second slave station participating in the conference call ends the call by going on-hook. The control circuit 2 executes step 501 in FIG.
When the termination of the second mobile station is detected in step S502, control for disconnecting the second mobile station from the conference call is performed in step 502. Further, in step 503, the communication state determination table 32
In step 504, the storage area corresponding to the DN of the second slave station is rewritten to the flag "0" which means the "empty" state, and at step 504, the second telephone number in the extension telephone EKT1 is changed.
The indicator lamp display control signal for setting the indicator lamp 15 corresponding to the slave station of No. 1 to the lighting pattern indicating "empty" is generated and sent to the extension telephone EKT1. Through the above processing, the second slave station is removed from the conference call, and the extension key EKT1 causes the indicator lamp 15 of the selection key corresponding to the second slave station to be displayed in an empty state.

As described above, according to the present embodiment, the slave station registration table 31 in which the extension numbers of the extensions to be slave stations are stored in association with the selection keys provided for each extension telephone set, respectively.
And a communication state determination table 32 that sequentially stores the state of each extension accommodated according to the change, and when the selection key is pressed in the extension telephone in the call or the master station in the conference call, , The state of the slave station corresponding to the pressed selection key is discriminated based on the stored contents of the communication state discrimination table 32, and if the slave station is idle, the table 31 is stored. Based on the contents, I tried to call the relevant slave station and connect to the conference call, so
The speaker of the master station, which is the organizer of the conference, does not need to leave the conference each time the slave station is called, as in the conventional case, and presses the selection key assigned to the desired slave station while participating in the conference call. It is possible to convene a child station with just a simple operation. Also, because the indicator light on the master station terminal informs the master station speaker of the communication status of each slave station, it is possible to confirm the response of the slave station by calling and confirm the slave stations participating in the conference. In addition to being easy to perform, it is possible to prevent useless call processing for a slave station that is busy with another extension.

Further, if the slave station corresponding to the selected key pressed in the master station during the conference call is already participating in the conference call including this master station, the slave station is disconnected from the conference call. As a result, the parent station that is the conference organizer can forcibly remove any child station from the conference call whenever it is necessary according to the progress of the conference, and thereby take the initiative in proceeding with the conference. be able to.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the indicator lamp 15 indicating the change in the state of the slave station in the master station is displayed by changing the lighting pattern thereof, but this is expressed by changing the lighting color of the indicator lamp 15, for example. Alternatively, in the case of an extension telephone equipped with a liquid crystal display (LCD), this LCD may be used to notify the master station speaker. In addition, the configuration of the private branch exchange, the data structure of the memory table, and the like can be variously modified and implemented without departing from the scope of the present invention.

[0034]

As described above in detail, according to the present invention, when the extension calling function key corresponding to an idle extension is operated in the extension terminal during a call, the operated extension calling function key is operated. When the extension calling function key corresponding to the extension already in the conference call is operated in the master station during the conference call, the extension corresponding to the call is connected to the common circuit for the conference call. Since the extension corresponding to the operated extension calling key is disconnected from the common circuit, the conference caller can easily call the slave station without leaving the conference call and the conference caller can It is possible to provide a private branch exchange capable of forcibly removing any child station from a conference call.

[Brief description of drawings]

FIG. 1 is a 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 the extension telephone set shown in FIG.

FIG. 3 is a diagram showing a slave station registration table and a communication state determination table in the storage circuit shown in FIG.

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

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

[Explanation of symbols]

1 ... Exchange circuit (SW), 2 ... Central control circuit (CC), 3
... memory circuit (MEM), 4 ... control data bus line, 1
0 ... Telephone body, 11 ... Handset, 12 ... Hook mechanism,
13 ... Dial key group, 14 ... Selection key group, 15 ... Indicator lamp, 21 ... Conference call control means, 31 ... Slave station registration table, 32 ... Communication state determination table, EKT1
-EKTn ... extension telephone, L1-Ln ... extension, SL1-
SLm ... local line, IC1 to LCn ... extension circuit, TRK1
TRKm ... Station line circuit.

Claims (1)

[Claims] 1. A plurality of extension terminals each having at least one extension calling function key provided in association with a desired extension are connected to the extension, respectively, and the plurality of extension terminals are selectively used as a common telephone for conference call. In a private branch exchange equipped with a conference call function that enables a conference call by connecting to a circuit, a call information storage unit for storing information indicating the call state of each extension, and from the extension terminal during a call. When the operation information of the extension call function key is sent, a call for determining the call state of the extension corresponding to the operated extension call function key based on the information stored in the call state storage means. When the state determining means and the extension corresponding to the operated extension calling function key are determined to be idle by the call state determining means, the extension is called and the common circuit is called. And a conference call control means for disconnecting the extension from the common circuit when it is determined that the extension corresponding to the operated extension calling function key is in a conference call. A private branch exchange.