JP3130651B2 - Private branch exchange - Google Patents

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 used in offices and offices, and more particularly to a private branch exchange having an automatic call back function.

[0002]

2. Description of the Related Art Generally, a private branch exchange is provided with various service functions, and one of them is an automatic call back (ACB;
matic Call Back) function. This A
The CB function means that when a called extension telephone is busy during extension interconnection, a predetermined AC
The called extension number is temporarily stored in the main storage unit of the exchange body by the registration operation B, and when the end of the called extension telephone is detected, the calling extension telephone is first called.
If the call is answered by the calling extension telephone, then the called extension telephone from which the end of the call is detected is called, and if the talker of this telephone answers, the called telephone is answered. This is a function for connecting the extension telephone and the calling extension telephone to establish a call state. By providing such a function, the user of the extension telephone can eliminate the trouble of calling again when the called extension telephone is busy even when the called extension telephone is busy. be able to.

[0003]

However, in such a conventional ACB function, only one called extension number can be registered in the ACB for each extension (telephone). For this reason, for example, when a call must be made to a plurality of locations by extension, if two or more locations are busy, even if the caller attempts to perform ACB registration, The ACB function described above could not cope. Accordingly, an object of the present invention is to provide a private branch exchange that enables ACB registration corresponding to a plurality of called extension terminals for each extension terminal.

[0004]

In order to achieve the above object, the present invention provides a notification that a called extension terminal is busy.
Registration for call return processing from the extension
In a private branch exchange where recording is possible, one caller extension
Information indicating the terminal and call return processing from the calling extension terminal
Indicates the number of called extension terminals for which a registration request has been made
Storage means for storing information and the caller extension terminal
A registration request for recall arrives and said storage means
If it is determined that there is no free storage area in the
Unable to register for call extension processing with former extension terminal
Call-back processing control means for notifying the
Sign. Also, in the present invention, the called extension terminal is busy.
Call back from the extension terminal of the caller who is informed
For private branch exchanges that can be registered for processing,
Information indicating one calling extension terminal and the calling extension terminal
Callees for which a registration request for call back processing has been made
Storage means for storing information indicating an extension terminal;
Call return processing from a source extension terminal to multiple called extension terminals
Is registered in the storage means after the registration for
Based on the information
Periodically monitor the end of each called extension terminal.
If a call is detected, the calling extension is idle.
Determination means for determining whether or not the
If the calling extension is determined to be idle,
Make a call to the calling source extension terminal and call the calling source extension.
If the terminal responds within a certain period of time,
The called extension terminal calls the called extension terminal and
Connects to the calling extension terminal, and
Terminates the call-back process if does not respond within a certain period
And a call-back processing control means.
You. Further, the storage means is associated with a calling extension terminal.
And stores information indicating the number of registrations related to call back processing.
The call return processing control means includes a plurality of
Registration for call return processing to the called extension terminal
The number of called extensions that have been registered.
The number of registrations stored in the storage means is added, and the caller extension
When the call between the terminal and the called extension terminal is terminated,
The number of called extension terminals for which the call of
It is characterized in that the stored registration number is subtracted.

[0005]

As a result, according to the present invention, every time a registration request for call back processing is sent from the calling extension terminal, the private branch exchange is associated with the calling extension terminal, for example, the extension of the called extension terminal. Numbers are stored one after another, and calls are sequentially made from the ones for which extensions have been detected for the extensions of the called extension numbers. Become. Also, if the extension
When a registration request for call back processing is issued from the
If there is no call, register for call return processing at the calling extension terminal
Is notified that the call cannot be made, and
Registration for call return processing to multiple called extension terminals
After the call has been made, each of the
The call termination of the call extension terminal is periodically monitored, and the call termination is detected.
If called, whether the calling extension is idle
Is determined, and the calling extension terminal is idle
Call the calling extension terminal, and
If the end responds within a certain period, the end call is detected
The called extension terminal is paged and called with the called extension terminal.
The connection with the calling extension terminal is established, and the calling extension terminal is fixed
If no response is received within the
You. For this reason, for example, when it is necessary to call a certain business at several places by extension, even if two or more places are busy, the caller returns to each of the called extension terminals It becomes possible to perform the registration of the process continuously, compared with the conventional automatic call return function in which only one called extension terminal can be registered for each extension terminal.
Workability related to extension calling can be significantly improved.

[0006]

FIG. 1 is a schematic diagram showing an example of a private branch exchange according to an embodiment of the present invention. In this figure, this private branch exchange includes an exchange circuit 1, a central control circuit 2, a storage circuit 3, extension circuits LC1 to LCn, and a local line circuit TRK1.
~ TRKm and control data bus lines 4 for transmitting various control signals between these circuits and central control circuit 2.
And The switching circuit 1 has an extension circuit L
A relay stand 5 is connected via C. This relay station 5
Is for giving an instruction to the central control circuit 2 such as a transfer to an extension for an incoming call from an office line.

Each of the extension circuits LC1 to LCn has an extension L1.
Extension lines EKT1 to EKTn are connected via Ln to Ln, and office lines SL1 to SLm are connected to the office line circuits TRK1 to TRKm, respectively. The above extension circuit LC
1 to LCn and the line circuits TRK1 to TRKm are connected to the extensions L1 to Ln and the line S, respectively.
In addition to monitoring the status of L1 to SLm, control information is exchanged with the central control circuit 2 to perform predetermined line control.

The switching circuit 1 is controlled by the central control circuit 2 to control the extension circuits LC1 to LCn and the local line circuits TRK1 to TRK1.
In addition to performing exchange connection with TRKm, exchange connection between the extension circuits LC1 to LCn is performed.

The storage circuit 3 has an ACB registration table 31 and an ACB registration presence / absence determination table 32, as shown in FIGS. The ACB registration table 31 is prepared for each extension, and stores a called extension number every time a registration request for a call back process (ACB) is input from each extension telephone. Each ACB registration table can store up to j extension numbers to be called.
The ACB registration presence / absence determination table 32 stores A for each extension.
A flag indicating whether or not CB registration has been performed is stored. If there is an extension performing ACB registration, an ACB registration flag indicating the number of times of ACB registration is stored in a storage area corresponding to the extension. It has become. When the ACB registration is not performed, the ACB registration flag is “0”.

The central control circuit 2 includes, for example, a microcomputer as a main control unit. In addition to ordinary control means such as exchange control for incoming and outgoing calls, an ACB registration control means 2a and an ACB execution control means 2b And The ACB registration control means 2a includes the extension telephones EKT1 to EKT1.
If the called extension is busy when an EKTn extension is called,
It monitors whether or not an ACB registration request arrives from the calling extension telephone. When the arrival is detected, the called extension is stored in a predetermined storage area of the ACB registration table 31 corresponding to the extension on the calling side. The numbers are sequentially written and stored. Note that the ACB registration control means 2a is configured to control the ACB registration from one calling extension telephone to a plurality of different called extensions.
When a registration request arrives, it has a function of storing each called extension number in the table 31 in association with the extension of the caller. The ACB execution control means 2b
The termination of all the called extensions registered in the ACB by the B registration control means 2a is monitored, and when the extension that has been terminated is detected, the extension on the calling side is determined based on the registered contents of the ACB registration table 31. After the call, the called extension that has been terminated is called and the two parties are switched and connected.

As shown in FIG. 2, for example, the extension telephones EKT1 to EKTn include a telephone main body 21, a handset 22, a hook mechanism 23, a dial key group 24, and a function key group 2 as shown in FIG.
5 and LEs provided corresponding to these function keys, respectively.
An indicator lamp 26 such as D and a liquid crystal display (LCD) 27 for displaying a destination telephone number, a call charge, and the like are provided. The function keys are used to activate various service functions provided by the exchange, and service types that can be activated are assigned to the function keys in advance. As a type of such a function key, for example, AC
There is an ACB key for registering / executing the B function. When these function keys are pressed to activate a predetermined service function, the indicator lamp 26 corresponding to the function key is turned on as necessary.

Next, the operation of the private branch exchange configured as described above will be described. Suppose that the extension numbers assigned to the extensions L1 and L2 are “5601” and “560”, respectively.
2 ", and it is assumed that the extension telephone EKT2 is already busy with an arbitrary extension telephone. In this state, it is assumed that the off-hook is performed at the extension telephone EKT1 by the calling party to make an extension call. Then, the off-hook is detected by the extension circuit LC1 via the extension L1, and the occurrence of transmission is notified from the extension circuit LC1 to the central control circuit 2 via the control data bus line 4.
The central control circuit 2 determines in step 4a of FIG.
When the off-hook of KT1 is detected, a preparation for receiving a telephone number is made to make it ready for reception, and then, in step 4b, the extension circuit LC1
To instruct a response to the call. Then, a dial tone is transmitted from the extension circuit LC1 having received the instruction to the extension telephone EKT1 via the extension L1.

In this state, it is assumed that the calling party dials in, for example, "5602" as an extension number.
Then, a dial signal corresponding to the extension number input by the dial is detected by the extension circuit LC1 and transferred to the central control circuit 2. The central control circuit 2 executes step 4
When the extension number is received in step c, the extension number is temporarily held, and it is determined in step 4d whether the called extension, that is, L2 is busy or idle. As a result, when it is determined that the extension L2 is busy, the central control circuit 2 instructs the extension circuit LC2 to transmit a busy tone in step 4e. Then, a busy tone is transmitted from extension circuit LC2 to extension telephone EKT1.

When the central control circuit 2 instructs the transmission of the busy tone in step 4e, the central control circuit 2 monitors the end request from the extension telephone EKT1 in step 4f, and determines whether or not the ACB registration request is input in step 4g. To monitor. Here, when the speaker of the extension telephone EKT1 goes on-hook and ends the call, the central control circuit 2 performs predetermined end control and ends the processing. On the other hand, extension phone EKT
Suppose that one speaker makes an ACB registration request by pressing the ACB key on the telephone during reception of the busy tone. When the central control circuit 2 detects the input of the ACB registration request, in step 4h, the AC corresponding to the calling side extension L1 is detected.
The B registration table 31 is examined, and it is determined whether or not there is an empty storage area in the table 31. As a result, when it is determined that there is no empty storage area in the table 31, the central control circuit 2 determines in step 4i that the extension telephone EKT.
1 is notified that ACB registration is impossible, and the process ends. If there is an empty storage area in the table 31 as a result of the above determination, the central control circuit 2 determines in step 4j any storage area in the ACB registration table 31,
For example, the extension number “5602” is written in the storage area 1, and “1” is added to the ACB registration flag corresponding to the extension number “5601” in the ACB registration presence / absence determination table 32 in step 4k to execute the ACB registration process. Do. In order to indicate that the extension telephone EKT1 is registering the ACB, the central control circuit 2 executes the extension telephone EKT in step 41.
Indicator lamp 2 corresponding to the ACB key on KT1
6 is turned on.

Thereafter, if it is desired to continue ACB registration, the speaker can register up to j extension numbers to be called by the same procedure as described above. FIG. 3A shows that the extension number “560” is stored in the storage area 1 as described above.
2, and the extension number “5603” is registered in the storage area 2.

If it is determined in step 4d that the extension L2 is idle,
Central control circuit 2 performs normal call control. That is,
Central control circuit 2 instructs extension circuit LC2 of the connection destination to transmit a call-in signal, and instructs extension circuit LC1 to transmit a ringback tone. Then, a call signal is sent from the extension circuit LC2 to the extension telephone EKT2, and the extension telephone LC1 is sent from the extension circuit LC1.
A ring back tone is transmitted to KT1. Then, when a response is made in the extension telephone EKT2 in this state, the central control circuit 2 connects the extensions L1 and L2 by the switching circuit 1 and puts into a talking state.

Now, the extension telephone EKT is obtained by the above-described procedure.
In the state where 1 has registered two ACBs, the central control circuit 2 periodically executes the following processing. That is, first, the central control circuit 2 executes the above A in step 5a of FIG.
By accessing the CB registration presence / absence determination table 32, it is determined whether or not there is an extension telephone that has performed ACB registration. As a result, if it is determined that there is no extension telephone with which the ACB registration has been performed, the central control circuit 2 ends the processing. If it is determined that there is an extension telephone that has performed ACB registration, the central control circuit 2 refers to the extension telephone, that is, the ACB registration table 31 corresponding to the EKT 1 (step 5b). Check the vacant state of the extension of the registered called extension number. As a result, if all the extensions of the called extension number are busy, the central control circuit 2 ends the processing. If, for example, only the extension telephone EKT2 has already ended the call, the central control circuit 2 subsequently determines in step 5c whether the extension telephone EKT1 is busy or idle. As a result, when it is determined that the extension telephone EKT1 is busy, the central control circuit 2 ends the processing. on the other hand,
If it is determined that the extension telephone EKT1 is idle, the central control circuit 2 determines in step 5d that the extension circuit LC1
, And generates a predetermined LCD display control signal for visually displaying the extension number of the extension telephone EKT2 on the LCD 27 and sends it to the extension telephone EKT1. Then, the extension telephone EKT1 notifies the incoming call by a ringing tone and displays the extension number “5602” on the LCD 27.

After transmitting the call signal transmission instruction and the LCD display control signal, the central control circuit 2 monitors in step 5e whether the extension telephone EKT1 responds within a predetermined time. If the extension telephone EKT1 does not respond within a predetermined time, the central control circuit 2 stops the ringing sound and the LCD display in step 5f and ends the processing. On the other hand, if the extension telephone EKT1 responds within a certain period of time, the central control circuit 2 calls the extension circuit LKT to call the empty called extension telephone EKT2 in step 5g.
Instructs C2 to transmit a call signal. If the speaker of extension telephone EKT2 answers this call by going off-hook and responding, central control circuit 2 proceeds to step 5
At h, the extensions L1 and L2 are connected to establish a call state.

The central control circuit 2 has the extension telephone EK
The end of the call between T1 and EKT2 is monitored in step 5i. When the end of the call is detected, the central control circuit 2 deletes the extension number “5602” from the ACB registration table 31 corresponding to the extension telephone EKT1 (step 5j) and the extension number in the ACB registration presence / absence determination table 32. "1" is subtracted from the flag corresponding to "5601" (step 5k). In step 51, the central control circuit 2 determines whether or not there is still a called extension telephone that is registered in the ACB by the extension telephone set EKT1. This determination is made by referring to the ACB registration presence / absence determination table 32.
This is performed by checking whether the ACB registration flag corresponding to the extension number “5601” is “0”. As a result, if the ACB registration flag is "0", the central control circuit 2 determines that there is no called extension telephone that has been registered in the ACB by the extension telephone EKT1, and step 5
At m, the indicator lamp 26 corresponding to the ACB key on the extension telephone EKT1 is turned off, and the process ends. On the other hand, if the ACB registration flag is other than "0", central control circuit 2 determines that there is still a called extension telephone whose ACB has been registered by extension telephone EKT1, and performs the processing while keeping indicator lamp 26 lit. finish. Thereafter, the central control circuit 2 periodically repeats the above-described processing as described above.

As described above, in this embodiment, the ACB registration table 31 for storing the extension numbers of a plurality of called extension telephones in accordance with the ACB registration request for each extension.
The termination of the called extension telephone is monitored based on the contents stored in the ACB registration table 31, and the call is sequentially called from the detected termination and connected to the extension telephone on the calling side that has performed the ACB registration. As a result, ACB registration corresponding to a plurality of called extension telephones can be performed for each extension telephone. Therefore, when making a telephone call to a plurality of locations at a time, for example, when a plurality of extensions are busy, the user of the extension telephone can deal with each of them by the ACB function. This is much more convenient than the conventional ACB function in which only the called extension can register the ACB.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, when a calling extension telephone registered in the ACB is called, an LCD display of the extension number to be called is performed in addition to notification by a ringing tone.
It is not always necessary to perform the above-mentioned LCD display on an extension telephone having no LCD. In the above embodiment, A
Although the previously set ACB key is pressed at the time of CB registration, this may be entered by dialing a predetermined special number. In addition, various modifications can be made to the configuration of the private branch exchange and the data structure of the memory table without departing from the gist of the present invention.

[0022]

As described above in detail, according to the present invention, there is provided a storage means capable of storing a plurality of extension numbers to be called in accordance with a registration request of a call-back process at the extension terminal of the caller, and this storage means. The extension terminals of the called extension number stored by the means are sequentially called from the one from which the end of the call is detected and connected to the extension terminal of the calling source, so that a plurality of extension terminals are provided for each extension terminal. It is possible to register the call back process corresponding to the called extension terminal, thereby improving the work efficiency of the extension terminal user regarding the extension call.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing an ACB registration table and an ACB registration presence / absence determination table in the storage circuit shown in FIG. 1;

FIG. 4 is a flowchart showing a control procedure and control contents of a central control circuit shown in FIG. 1;

FIG. 5 is a flowchart showing a control procedure and control contents of a central control circuit shown in FIG. 1;

[Explanation of symbols]

1. Switching circuit, 2. Central control circuit, 3. Storage circuit, 4.
Control data bus line, 5 relay station, 21 telephone set, 22 handset, 23 hook mechanism, 24 dial key group, 25 function key group, 26 indicator lamp, 27 liquid crystal display (LCD) , 31 ... ACB registration table, 32 ... ACB registration presence / absence determination table, EKT1
~ EKTn ... Extension telephone, L1 ~ Ln ... Extension, SL1 ~
SLm: office line, LC, IC1 to LCn: extension circuit, TR
K1 to TRKm: office line circuits.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04M 3/58 H04M 3/42 H04Q 3/58 101

Claims (3)

(57) [Claims] 1. A process for returning a call from an extension terminal of a caller, which is informed that a called extension terminal is busy.
In a private branch exchange that can register a caller, information indicating one caller extension terminal and the caller extension terminal
From the end of the call request process.
Storage means for storing information indicating a call extension terminal; and a registration request for a call back from the call originating extension terminal.
And it is determined that there is no empty storage area in the storage means.
Is called, the call originating extension terminal is
A private branch exchange, comprising: a call-back processing control unit for notifying that registration for the system cannot be performed. 2. A notification that the called extension terminal is busy on a call.
For call back processing from the extension terminal that is performing the call
In a private branch exchange that can register a caller, information indicating one caller extension terminal and the caller extension terminal
From the end of the call request process.
Storage means for storing information indicating a call extension terminal; and a call from the call originating extension terminal to a plurality of called extension terminals.
After registration for return processing has been made,
Connection by call back processing based on stored information
Regularly monitor the end of each target called terminal.
When the end of call is detected, the calling extension terminal
Determining means for determining whether or not the call is a dollar; and determining that the calling extension terminal is idle by the determining means.
If determined, the calling extension terminal is called.
No, if the calling extension terminal responds within a certain period of time
In this case, the called extension terminal on which the
Connection between the called extension terminal and the calling extension terminal
If the calling extension does not respond within a certain period of time,
Call-back processing control means for ending the call-back processing.
Private branch exchange characterized by being equipped. 3. The storage means corresponds to a calling extension terminal.
Information indicating the number of registrations relating to the call-back processing, and the call-back processing control means transmits the information
It is registered for call-back process against the called extension terminal number
The number of called extension terminals that have registered this
The number of registrations stored in the storage means is added to the
When the call between the line terminal and the called extension terminal is terminated,
The storage means for the number of called extension terminals for which the call has been completed.
Subtracting the number of registrations stored in the storage device.
The private branch exchange according to 2.