JPS6374364A - Pushbutton telephone system - Google Patents

Abstract

PURPOSE:To attain the communication of extensions between facsimile equipments by providing a polarity inversion detection circuit detecting the polarity inversion of a trunk line to a trunk line interface circuit and providing a dial signal detection circuit detecting a dial signal to a facsimile terminal interface circuit detecting a dial signal to a facsimile terminal interface circuit. CONSTITUTION:At the call of a facsimile equipment 50, a facsimile terminal interface device 51' is not connected unconditionally. Whether the destination is a trunk line or an extension is discriminated from the dial signal of the FAX 50 and a call and connection control are applied respectively to the trunk line and the extension depending on the result of discrimination. Thus, if plural extensions connected to a facsimile equipment exist, the facsimile equipment can make communication with facsimile equipments connected via a trunk line and facsimile equipments being extension.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an improvement in a button telephone device to which a facsimile device can be connected.

(Prior Art) Conventionally, this type of button telephone device has been configured as follows, for example. Figure 3 shows its block configuration.
This device includes office line interface circuits (COLJ) 21 to 2n provided corresponding to a plurality of office lines 11 to 1n, respectively, and terminal interfaces (COLJ) provided for each of a plurality of key telephones (EKT) 31 to 3m. STU) 41-4
A facsimile terminal interface circuit (FSTtJ) for connecting the facsimile machine (FAX) 50 to
) 51, each of these interface circuits 21-
A central control circuit (CCU) connects 2n, 41 to 4m, and 51.
) 70, the crosspoint switch 60 selectively connects each button telephone l1131.
~btan phone! The facsimile device 150 is configured to perform calls or communications between the fi 31 to 3m and each of the office lines 11 to 1n, and between the facsimile machine 150 and each of the office lines 11 to 1n. Note that 80 is a tone signal generation section that generates various tone signals, and 90 is a power supply section.

Figure 4 shows the station line interface circuit 2 of the above device.
1 and a terminal interface circuit 41.51. In addition, other station line interface circuits 22~
The configurations of 2n and terminal interface circuits 42 to 4m are the same as those of the station line interface circuit 21 and terminal interface circuits 41 and 41, respectively.

The office line interface circuit 21 has a 16-channel detection circuit 214 as a calling signal detection circuit, and further has a calling signal passing circuit 219 that passes a 1300 Hz calling signal. Of these, the calling signal passing circuit 219 is a circuit in which a capacitor 219a and an audio transformer 218' are connected in series, and a changeover switch 211 is connected in series between the chip line T of the office line 11 and the cross point switch 80. It is being The capacitance of the capacitor 219a is 1300
The impedance is low for Hz ringing signals, 16
The impedance is set to be high for a Hz calling signal. Further, the changeover switch 211 operates according to instructions from a control circuit (CC) 210 to selectively connect the calling signal passing circuit 219 and the diode bridge circuit 213 to the central office line 11.

On the other hand, the 16H2 detection circuit 214 is connected between the chip 11T and the ring IR of the office line 11 via a changeover switch 216 after passing through a bypass circuit 212 for passing 18 Hz and a diode bridge circuit 213, respectively. This changeover switch 216 operates according to instructions from the control circuit 210 similarly to the changeover switch 211, and
In contrast, the 16H2 detection circuit 214 and the DC loop circuit 2
15 is alternatively connected.

On the other hand, the facsimile terminal interface circuit 51 is
The above office line interface circuit 21 and facsimile machine 5
transformer 511 and signal line 517 connecting between
A mute switch 51 is included in this signal line 517.
8 is an insertion. Also, this terminal interface circuit 51
are the 16Hz generation circuit 513 and the DC current generation circuit 5
It has 14. These 16Hz generation circuit 513 and DC current generation circuit 514 are connected to a control circuit (CC) 51
It is selectively connected to the signal line 517 via a changeover switch 512 which is activated by an instruction of 0. In addition, 515
516 is a DC current detection circuit; 516 is a DC current detection circuit;
This DC current detection circuit 516 is connected to the DC current generation circuit 5.
When direct current is supplied from 14 to facsimile device 50, this state is detected and notified to control circuit 510.

Also, a terminal interface circuit 41 for the button telephone 31
has an audio transformer 413 connected to the button telephone 1131 via an audio signal line 411, and a data transformer 414 connected to the button telephone 131 via a control signal line 412. A transformer 413 connects the audio signal line between the button telephone 31 and the crosspoint switch 60. Further, a data transformer 414 connects a control data line between the button telephone 50 and the central control circuit 70. still,
415 is an interface circuit for transmitting control data.

In such a configuration, for example, if the station 111 is connected to the subscriber telephone network and in this state a 16 Hz paging signal arrives from an exchange example (not shown) to the facsimile machine, this 16 Hz paging signal is sent to the bypass circuit 212. , diode bridge circuit 213.16Hz detection circuit 214,
Changeover switch 216 and diode bridge circuit 21
3 and is thereby detected by the 16-detection circuit 214. Then, a detection signal is generated from the 16Hz detection circuit 214, and this fact is transmitted from the control circuit 210 to the central control circuit 70, which causes the central control circuit 70 to control the control circuit 5 of the facsimile terminal interface circuit 51.
A switching control instruction i is output to 10. Then, a switching signal is generated from the control circuit 510 and the switching signal 512 is
is switched to the 16-channel generation circuit 513 side, and as a result, the 16-channel
A calling signal 16- is generated from the - generating circuit 513 and sent to the facsimile machine 50, and as a result, the facsimile machine 50 is called. At this time, the central control circuit 70 releases the mute switch 518 via the control circuit 510, so that the calling signal is transmitted to the central office line interface circuit 21.
Prevent it from being sent to the side. When the facsimile machine 50 automatically responds to this, the terminal interface circuit 5
The current is detected by the DC current detection circuit 516 of No. 1, and the fact is notified to the central control circuit 70 via the control circuit 510. Then, a switching control instruction is sent from the central control circuit 70 to the control circuit 510, and as a result, the control circuit 510
operates and the changeover switch 512 switches to the DC current generation circuit 51.
As a result, the loop current is supplied to the facsimile machine 50 from the DC current generating circuit 514. The central control circuit 70 also issues a switching control instruction to the control circuit 210 of the office line interface circuit 21, thereby switching the changeover switches 211 and 216 to the diode bridge circuit 213 side and the DC loop circuit 215 side, respectively. Then, a DC loop is formed between the Cheetub line T and the ring line R of the central office line 11, thereby establishing a connection between the calling party and the facsimile machine 50, so that the facsimile machine 50 can communicate.

Further, at this time, the formation of the DC loop is detected by the DC loop circuit 215, and this fact is notified to the central control circuit 70 via the control circuit 210. Then the central control circuit 7
0 sends display data indicating that the central office line 11 is in use to each of the button telephones 1131-3m via the terminal interface circuits 41-4m. Therefore, in this state, it is no longer possible to access the central office line 11 using the key telephones l1131-113m.

Furthermore, if the office line 11 is connected to a facsimile network and a 1300tlz paging signal arrives in this state, the 1300tlz paging signal is sent to the changeover switch 211.
and the audio transformer 218 via the capacitor 219a.
', and is sent from this audio transformer 218' to the facsimile terminal interface circuit 51 via the crosspoint switch 60. The signal is then supplied to the facsimile machine 50 through the audio transformer 511 and main signal line 517 of the terminal interface circuit 51, respectively. In addition, in the above-mentioned office line interface circuit 21, the calling signal 1300- is sent to the 16-detection circuit 2 via the bypass circuit 212 and the diode bridge circuit 213.
14, but the level of the 1300Hz ringing signal is -20 to -36 (about IBm and the ringing signal to 16 (
75Vrms), so 16H
2 detection circuit 214 will not cause false detection. When the calling signal 130082 is then supplied to the facsimile machine 50, the facsimile machine 50 detects this calling signal, automatically responds, and closes the internal DC loop circuit. Then, a DC current flows from the power supply 515 of the terminal interface circuit 51 to the facsimile machine 50 via the DC current detection circuit 516, the DC current generation circuit 514, the changeover switch 512, and the main signal line 517. It will be inspected. The detection output is sent from the DC current detection circuit 516 to the central control circuit 70 via the control circuit 510. As a result, the central control circuit 7o sends a switching control instruction to the control circuit 210 of the office line interface circuit 21, and thereby the switching control circuit 7o
216 are switched to the diode bridge circuit 213 side and the DC loop circuit 215 side, respectively, to form a DC loop of the office line 11. Thus, facsimile communication between the calling party and the facsimile 8150 is possible from now on.

On the other hand, when the facsimile device 5o makes a call, when the DC loop of the facsimile device 50 is closed, a DC current is supplied to the facsimile device 50 from the DC current generation circuit 514, and this is detected by the DC current detection circuit 516 and sent to the center. The signal is transmitted to the control circuit 7o. Then, the central control circuit 7o connects the terminal interface circuit 51 and the office line interface circuit 21 using the crosspoint switch 60, and then switches the changeover switches 211 and 216 to the diode bridge 213 and DC loop circuit 215 sides, respectively. As a result, the DC loop of the station line 11 is closed. When a dial signal is sent from the facsimile machine in this state, if the dial signal is a DTMF signal, this signal is sent to the central office line 11 via the transformer 511, crosspoint switch 60, and transformer 218'. On the other hand, when the dial signal is a dial pulse, this dial pulse is detected by the DC current detection circuit 516 and transmitted to the central control circuit 80, which controls the changeover switches 211 and 216 on and off to loop the DC current. A dial pulse is sent to the exchange by intermittent . In this way, a call is made from the facsimile device, and if the other party's device responds to the call, it becomes possible to transmit a facsimile signal.

Incidentally, when the communication is completed, the following operation is performed. That is, if the facsimile machine 50 releases the DC loop first, this is detected by the DC current detection circuit 516 and transmitted to the central control circuit 70 via the control circuit 510.
As a result, a switching instruction is output from the central control circuit 70 to the control circuit 210, the changeover switch 211 returns to the calling signal passing circuit 219 side, and the apparatus returns to the standby state. In addition, if the DC loop of the central office line 11 is released first, this is detected by the DC loop circuit 215 and transmitted to the central control circuit 70, which causes the terminal interface circuit 51 to be terminated from the central control circuit 7o to the control circuit 510 of the terminal interface circuit 51. When a call command is issued, the polarity of the loop is reversed by a polarity reversal circuit (not shown), which causes the facsimile machine to terminate the call.

As described above, with this apparatus, it is possible to perform facsimile communication with a counterpart apparatus using a subscriber network or a facsimile network, just as in the case where a facsimile apparatus is directly connected to a central office line.

However, such a conventional device is a facsimile machine 5.
0 makes a call, it is unconditionally connected to the office line 11. Therefore, even if, for example, a facsimile terminal interface circuit is added and multiple facsimile machines are installed, each of these facsimile machines is connected to the office line 11. Facsimile machines can only communicate with other devices via a line, and cannot perform extension communication between facsimile machines.

Therefore, even if facsimile machines are installed in relatively separate locations, such as on different floors, for ease of use, these facsimile machines can be effectively used as a means of communication between extensions. There wasn't.

(Problems to be Solved by the Invention) As described above, the conventional button telephone device has a problem in that even if multiple extension lines connected to facsimile devices are provided, extension communication cannot be performed between these facsimile devices. The present invention has focused on this point, and has enabled not only communication via central office lines but also extension communication between facsimile machines, thereby making it possible to use facsimile machines more effectively. The present invention aims to provide a button telephone device.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a polarity reversal detection circuit A for detecting polarity reversal of the central office line in the central office line interface circuit, and also provides a polarity reversal detection circuit A for detecting polarity reversal of the central office line, and also provides a facsimile terminal interface circuit for detecting polarity reversal from the facsimile machine. A dial signal detection circuit B is provided to detect the transmitted dial signal, and the center! The IJ control circuit includes a call determining means C for determining whether the call is an outgoing call or an incoming call from the facsimile machine based on the detection output of the polarity reversal detection circuit when the DC loop of the facsimile machine is closed, and a detection circuit for the dial signal detection circuit. Destination determination means for determining from the output whether the destination of the facsimile device is a central office line or another facsimile device connected to an extension; and facsimile call connection control means E.
The facsimile call connection control means E, when the call determination means C determines that the call is from a facsimile machine, releases the direct current loop of the central office line by the central office line interface circuit, and calls the above-mentioned destination. The determining means determines the destination, and if the destination is a central office line, the central line interface circuit closes the DC loop of the central line, and then sends out the dial signal of the destination, and if the destination is an extension. In the case of other facsimile machines, a cross-point switch circuit connects the corresponding facsimile terminal interface circuits, and a calling signal is sent from this interface circuit to the facsimile machine.

(Function) As a result, when a facsimile machine makes a call, the call is first detected from the presence or absence of polarity reversal on the office line, and the direct current loop of the office line is temporarily held in an open state, and in this state, the facsimile machine It is determined from the dial signal generated from the dial signal whether the destination is a central office line or another facsimile machine on the extension, and depending on the result of this determination, calling and connection control to the central office line or the corresponding extension is performed. , the facsimile machine operator can communicate not only with the facsimile machine connected via the central office line, but also with other facsimile machines connected to the extension, by simply inputting the telephone number or extension number corresponding to the communication partner. . Therefore, the uses of the facsimile device can be expanded.

(Embodiment) FIG. 2 shows a circuit configuration of a button telephone device according to an embodiment of the present invention. In addition, in the same figure, the fourth
Components that are the same as those in the figures are given the same reference numerals and detailed explanations will be omitted.

The office line interface circuit 21' is provided with a polarity reversal detection circuit 220 that detects the presence or absence of polarity reversal of the office line 11, and the detection output of this polarity reversal detection circuit 220 is sent to the central control circuit 70' via the control circuit 210. sent to. Further, the facsimile terminal interface circuit 51' is provided with a dial signal detection circuit (DD) 519. This dial signal detection circuit 519 detects a DTMF signal generated from the facsimile machine 50 when the facsimile machine 50 makes a call, and transmits information about the telephone number or extension number of the office line represented by this signal to the central control circuit via the control circuit 510. 70'. If the dial signal generated from the facsimile machine 50 is a dial pulse, it is detected by the DC current detection circuit 516 and transmitted to the central control circuit 70'.

By the way, the central control circuit 70' controls each button telephone 31.
~3m mutual interrogation and button telephone 31~3m and station 11
In addition to means for controlling connection between 1 and 1 m, the apparatus includes means for determining whether a call is incoming or outgoing, a means for determining a destination, and a facsimile call connection control means for connection of a facsimile machine. The incoming and outgoing call determining means detects whether or not the polarity of the central office line 11 is reversed within a certain period of time after the DC loop of the central office line 11 is formed once the DC loop of the facsimile machine 50 is formed. The determination is made from the detection output of the circuit 220, and if the polarity is reversed as a result of this determination, it is recognized as an incoming call, and if the polarity is not reversed, it is recognized as an outgoing call. The destination determining means determines whether the destination of the facsimile device 50 is a central office line or another facsimile device connected to an extension from the dial signal detected by the DC current detection circuit 516 or the dial signal detection circuit 519. The facsimile call connection control means recognizes the destination from the discrimination result of the destination discrimination means when the facsimile machine @50 makes a call based on the discrimination result of the call origination/reception discrimination means, and the destination is the central office line 1.
1, the DC loop of the central office line 11 is closed and a dial signal is sent.If it is another facsimile machine connected to an extension, the corresponding terminal interface circuits are connected by the cross-point switch 60. to send out a calling signal.

With such a configuration, when the facsimile machine 50 forms a DC loop in order to make a call in the standby state, this is detected by the DC current detection circuit 516 of the terminal interface circuit 51' and sent to the central control via the control circuit 510. is transmitted to circuit 70'. Then the central control circuit 7
0' first outputs a switching instruction to the control circuit 210 of the office line interface circuit 21' and switches the changeover switch 211.21.
6 are respectively switched to the diode bridge 213 and DC loop circuit 215 sides, thereby forming a DC loop of the central line 11. In this state, it is determined from the detection output of the polarity reversal detection circuit 220 whether or not the polarity of the central line 11 has been reversed. Here, the polarity of the central office line is reversed within several meters to several hundred meters sea after the DC loop is formed when a call is received, but it is not reversed when a call is made.

For this reason, the polarity of the office line 11 is not reversed since it is currently an outgoing call, and the central control circuit 70' detects this through the polarity reversal detection circuit 2.
Detection is made from the detection output of 20, and control for transmission is then performed.

That is, first, the changeover switches 211 and 216 are connected to the calling signal passing circuit 219 and the 161h detection circuit 214, respectively.
The terminal interface circuit 51' is then connected to the tone signal generator 80 by the cross point switch 60. Then, this tone signal generating section 80 generates a dial tone and sends it to the facsimile machine 50. On the other hand, when the facsimile machine 50 sends out a dial signal of the destination, the dial signal is detected by the dial signal detection circuit 519 if it is a DTMF signal, and by the DC current detection circuit 516 if it is a dial pulse. The number information is sent via control circuit 510 to central control circuit 70'. Then, the central control circuit 70'
Based on this number information, it is determined whether the destination is a central office line or an extension line, and call control is performed according to the result of this determination. For example, if the destination is a central office line, first connect the terminal interface circuit 51' and the central office line interface circuit 21' using the Osuboin switch 60, and then connect the changeover switches 211 and 216 to the diode bridge 213 and the DC loop, respectively. Switch to the circuit 215 side to form a DC loop of the office line 11, and in this state, first switch to the dial detection circuit 2.
The selector switch 216 is turned on and off in accordance with the telephone number of the office line detected through the DC current detection circuit 216 or the DC current detection circuit 216, thereby intermittent the DC loop and send dial pulses to the exchange.

If the destination facsimile machine responds to this call, facsimile communication between the facsimile machines is possible thereafter via the central office line.

On the other hand, if the destination is an extension, the central control circuit 70'
First, the cross point switch 60 connects the facsimile terminal interface circuit corresponding to the destination facsimile machine, and then the changeover switch 514 of this terminal interface circuit is switched to the 16-way side to connect the facsimile machine to the facsimile terminal interface circuit. A ringing signal is provided to ring the facsimile machine. Note that, at this time, the mute switch 518 is set to the released state. In response, when the facsimile machine responds and closes the DC loop, this is detected via the DC current detection circuit 516 and the mute switch 518 is closed. Thus, a communication path is formed between the facsimile machines of the extensions, and thereafter facsimile communication via the extensions becomes possible between these facsimile machines.

In this embodiment, when the facsimile device 50 makes a call, the facsimile terminal interface device 51
′ is not unconditionally connected to the central office line, it determines from the dial signal whether the destination is a central office line or an extension line, and performs paging and connection control for the central office line and extension line, respectively, according to the result of this determination. Therefore, when there are a plurality of extensions to which facsimile machines are connected, communication can be performed not only with the facsimile machines connected via the central office line, but also between the facsimile machines of the extensions.

Therefore, the uses of the facsimile device can be expanded. Furthermore, when an operator wants to send documents to a different floor, etc., the operator can use an extension line to send the documents by facsimile, which reduces the time and effort required to transport the documents, thereby improving the efficiency of office processing.

Note that the present invention is not limited to the above embodiments. For example, in the above embodiment, the office line interface circuit 21' includes a polarity reversal detection circuit 220, and the facsimile terminal interface circuit 51' includes a dial signal detection circuit 519.
Although these circuits are newly provided, if they are already provided, the circuits may be used as they are. In addition, the configurations and control procedures of the incoming/outgoing call determination means, the destination determination means, and the facsimile call connection control means may be modified in various ways without departing from the gist of the present invention.

[Effects of the Invention] As detailed above, according to the present invention, a polarity reversal detection circuit A for detecting polarity reversal of a central office line is provided in the central office line interface circuit.
In addition, the facsimile terminal interface circuit is provided with a dial signal detection circuit B for detecting the dial signal sent from the facsimile machine, and the central control circuit is configured to detect the polarity reversal detection circuit when the DC loop of the facsimile machine is closed. an incoming/outgoing call determining means C for determining from the output whether the call is an outgoing call or an incoming call from the facsimile machine;
A destination determining means for determining whether the destination of the facsimile device is a central office line or another facsimile device connected to an extension from the detection output of the dial signal detection circuit, and a facsimile call connection control device E are provided. When the facsimile call connection control means E determines that the call is from a facsimile machine by the incoming/outgoing call determining means C, the central office line interface circuit releases the direct current loop of the central office line and transmits the call to the destination determining means. If the destination is a central office line, the central line interface circuit closes the direct current loop of the central line, and then the dialing signal of the destination is sent, and if the destination is an extension, the other facsimile machine In this case, by connecting the corresponding facsimile terminal interface circuits using a cross-point switch circuit and sending a paging signal from this interface circuit to the facsimile machine, communication via the central office line as well as the facsimile machine can be performed. It is possible to provide a key telephone device that allows mutual extension communication and thereby allows a facsimile device to be used more effectively.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a circuit diagram showing a part of the configuration of a button telephone device according to an embodiment of the present invention, and FIG. 3 is an overall diagram of a conventional one-place button telephone. FIG. 4 is a circuit diagram showing the structure of a part of the device. A...Polarity reversal detection circuit, B...Dial signal detection circuit, C...Calling/incoming call discrimination means, D...Destination discrimination means, E...Facsimile call connection control means, 11-1
n...central line, ■...chip line, R...ring line,
21' to 2n'... Office line interface circuit (COU
), 31-3m...key telephone (EKT), 41
~41... Terminal interface for button telephone (
STtJ), 50...Facsimile machine, (FAX)
, 51=... facsimile terminal interface circuit (FSTtl), 60... cross point switch (XP), 70-... central control circuit (CCLJ),
80... Tone signal generation section, 90... Power supply section, 21
0.510...Control circuit (CC), 211,216,
512... Selector switch, 215... DC loop circuit, 220... Polarity reversal detection circuit, 513... 16
Hz generation circuit, 514... DC current generation circuit, 515
...DC power supply, 516...DC current detection circuit, 51
7... Main signal line, 518... Mute switch, 519... Dial signal (DTMF signal) detection circuit.

Claims (1)

[Claims] A station line interface circuit provided corresponding to the station line,
A plurality of facsimile terminal interface circuits to which facsimile machines are connected, a cross-point switch circuit for selectively connecting the central office line interface circuit and the facsimile terminal interface circuit, and a cross-point switch circuit for controlling these circuits. at least a central control circuit for selectively connecting each facsimile device to a central office line; the central control circuit includes a polarity reversal detection circuit for detecting polarity reversal of the central office line in the central office line interface circuit; The interface circuit is provided with a dial signal detection circuit for detecting a dial signal sent from the facsimile machine, and the central control circuit is configured to detect the dial signal from the facsimile machine from the detection output of the polarity reversal detection circuit when the DC loop of the facsimile machine is closed. an incoming/outgoing call determining means for determining whether a call is received or an incoming call; and a destination determining unit for determining whether the destination of the facsimile device is a central office line or another facsimile device connected to an extension line based on the detection output of the dial signal detection circuit. means, and when the calling/receiving call determining means determines that the call is from a facsimile machine, the central office line interface circuit releases the direct current loop of the central office line, and causing the calling destination determining means to determine the calling destination; If the destination is a central office line, the central line interface circuit closes the direct current loop of the central line, and then sends out the dial signal for the destination.
and facsimile call connection control means for connecting the corresponding facsimile terminal interface circuits by the cross-point switch circuit and transmitting a call signal from the interface circuit to the facsimile machine when the destination is another facsimile machine of the extension; A button telephone device characterized by being provided with.