JPS6349960B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a connection method for a button telephone device that allows a standard telephone to be connected to the button telephone device without compensating for insertion loss occurring within the main device.

In a button telephone device (simplified switching telephone device), a key telephone device is connected to the main device, and has functions such as selecting a line, putting it on hold, and making calls between telephones by operating buttons or the like. In the case of electronic button telephone devices, the main device and each button telephone device are connected by three pairs of lines or two pairs of lines in a half-duplex system. In the case of a button telephone device with three pairs of lines, one pair of lines constitutes a communication path, that is, a transmission path for communication signals. Another pair of lines constitutes an upstream transmission line, and the remaining one
The paired lines constitute a down transmission line. The uplink transmission line is a data transmission line through which the electronic button telephone transmits the number of the office line to which it wishes to connect, etc. to the main device, and the downlink transmission line is the data transmission line through which the electronic key telephone transmits the telephone number, etc. of the office line to which it wishes to connect, and the downlink transmission line is the data transmission line through which it transmits the telephone number, call, and hold status on the office line, etc. This is a data transmission line for transmitting data from the main unit to the electronic button telephone device in order to visually display the information on the electronic button telephone device. Both of these combined data transmission paths transmit time-divided pulse signals.

As described above, the electronic button telephone device in the button telephone device is susceptible to the influence of the distributed capacity of the transmission path because pulse signals are transmitted through the upstream and downstream transmission paths. For this reason, when attempting to perform long-distance transmission, a time delay of the pulse signal tends to occur, making it difficult to achieve this. Furthermore, it is not possible to connect devices such as facsimile devices that can only be connected to ordinary telephone lines to the button telephone device.

Therefore, when installing a telephone far from the main device or when using the above-mentioned equipment with a button telephone device, it is necessary to connect an ordinary telephone (hereinafter referred to as a standard telephone) that is different from a button telephone to the button telephone device. There was a demand for the ability to do so.

For this purpose, the first possible connection method is:
There is a method in which an interface circuit is provided to convert the functions of a standard telephone as if it were a button telephone, and the main device and the standard telephone are connected via this interface circuit. The interface circuit used in this connection method must have functions equivalent to the circuit selection button, ringer circuit, or line display function of a normal button telephone, even if there is some deterioration in function. It is said that

Now, when a standard telephone is connected to the key telephone device in this manner, a problem arises in the speech level. That is, in the above-mentioned electronic key telephone device having two or three pairs of lines, insertion loss may occur due to technical reasons when a cross point between the key telephone and the central office line trunk or extension trunk is configured in the main device. There is. For button telephones, for example, by providing an amplifier for compensating insertion loss in the circuitry within the telephone, the insertion loss can be compensated and the speech level can be maintained at an appropriate level. However, for standard telephones, it is not possible to compensate for such insertion loss within the telephone. Therefore, when a standard telephone is connected to a button telephone device, it is necessary to compensate for this loss using the aforementioned interface circuit. However, when providing an amplifier for insertion loss correction in the interface circuit, it is technically difficult and expensive to use bidirectional amplifiers (for example, two 2-wire to 4-wire conversion circuits, an amplifier circuit corresponding to each direction, and two (Consists of a circuit to prevent howling caused by imperfections in the wire-to-four wire conversion circuit.)
This made it difficult to put it into practical use in inexpensive devices such as key telephones.

The present invention has been made in view of the above-mentioned circumstances, and is applied to a button telephone device in which insertion loss occurring within the main device is corrected in each button telephone device.
In particular, it is an object of the present invention to provide a connection method for a button telephone device that can connect a standard telephone without compensating for insertion loss.

In the present invention, a switching device is provided in the interface circuit provided for the standard telephone, and when the standard telephone makes a private video call, the standard telephone is connected to the terminal circuit in the main device through the contacts of this switching device. On the other hand,
When making a telephone call to the central office line, connect the standard telephone in a straight line to the central telephone line through the other contacts of this switch.
Achieve the above objectives.

The present invention will be explained in detail with reference to Examples below.

FIG. 1 shows a schematic configuration of a button telephone device to which a standard telephone is connected. A plurality of button telephones 2 and 3, a standard telephone 5 via an interface circuit 4, and a central office line 6 are connected to the main device 1. The main device 1 preferably includes terminal circuits 11 to 13 provided for each telephone, an extension circuit 14 for making extension calls, a central office line circuit 15 for making central telephone calls for the button telephones 2 and 3, and a terminal circuit. A cross-point circuit 16 is provided for connection to an extension circuit or a central office line circuit.

First, an extension call using a button telephone in this button telephone device will be explained. It is assumed that button telephone 2 is a calling telephone and button telephone 3 is a called telephone.
The caller operates a line selection button corresponding to the extension circuit 14 to connect the key telephone 2 to the extension circuit 14 via the terminal circuit 11 and the cross point 16A of the crosspoint circuit 16. After this, when the caller performs a dial operation on the key telephone 3, a counting circuit (not shown) performs counting, and the key telephone 3 is called based on this. When the called party responds to this call by operating the line selection button corresponding to the extension circuit 14, the button telephone 3 is connected in parallel to the extension circuit 14 via the terminal circuit 12 and the cross point 16B of the crosspoint circuit 16. be done. This allows an extension path between the two.

Next, a central office line call using the button telephone 2 will be explained. When the operator of the button telephone 2 operates the line selection button corresponding to the central office line 6, the button telephone 2 is connected to the central office line 6 via the terminal circuit 11, the cross point 16C of the crosspoint circuit 16, and the central office line circuit 15. , local line calls are possible.

The same parts as in Fig. 1 are given the same reference numerals as in Fig. 2.
The figure is for explaining in more detail the operation of a central office line call between the main device 1 and the key telephone 2. Since the transmission distance for extension calls is short, correction of insertion loss at cross points etc. does not pose a particular problem even with standard telephones, which will be described later. Therefore, a description of the operation regarding extension calls will be omitted.

Now, when the operator of the key telephone 2 raises the handset 21 to make a call to the central office line, the hook switch 22 is operated in conjunction with this and goes off-hook.
In this state, the operator presses the line selection button 23A corresponding to the office line circuit 15 among the plurality of line selection buttons 23.
When you operate , data indicating the off-hook status of the hook switch 22 and the line selection button 23 are displayed.
Both data regarding A are supplied to the parallel-to-serial conversion circuit 24. The parallel-to-serial conversion circuit 24 converts the supplied data into serial data, and converts the supplied data into serial data, and connects the data to the data upstream path 71 in the connection cable 71 that accommodates three pairs of lines.
This is sent to the upstream data receiving circuit 11A in the terminal circuit 11 via A. Upstream data receiving circuit 1
1A supplies this upstream data 18A to the control circuit 17.

Based on this, the control circuit 17 outputs a control signal 1 that controls the connection of the cross point 16C of the cross point circuit 16.
8B and connect the fork point 16C. In addition, the control circuit 17 is connected to the station line relay 1 in the station line circuit 15.
5A is sent out, and the central office line 6, which was connected to the station arrival detection circuit 15B, is switched to the communication path transformer 15C. This enables the dial operation, and when a call is started after the dial operation and the response from the other party's telephone, the voice output from the transmitter 21T of the button telephone 2 is transmitted to the insertion loss correction amplifier 25T, the hybrid circuit 26, and the connection cable 71. audio path 71B, terminal circuit 11
the communication line transformer 11B in the internal communication line, the intersection 16C of the crosspoint circuit, and the communication line transformer 15 in the central office line circuit.
C and the make side of the station line relay contact 15A, and then sent to the station line 6.

On the other hand, the voice transmitted from the other party's telephone follows the above-mentioned route in reverse, reaches the hybrid circuit 26 in the button telephone 2, and is supplied to the receiver 21R via an insertion loss correction amplifier 25R.
This makes it possible to make telephone calls using the key telephone 2 over the central office line.

In order to display the state of this central line call on the key telephone 2, the control circuit 17 controls the downlink data 18.
Send D. This downlink data 18D is supplied to the serial-to-parallel converter 27 in the button telephone 2 via a downlink data transmission circuit 11C in the terminal circuit 11 and a data downlink path 71C in the connection cable 71.
The parallel data converted by the serial/parallel converter circuit 27 causes a corresponding element of the line display element 28 made up of a plurality of light emitting diodes to light up, for example, continuously, to indicate that the office line 6 is busy.

Next, the reception of a call on the button telephone 2 will be explained.
When a calling signal is sent from the office line 6 to the button telephone device, the office line relay contact 1 in the office line circuit
The station arrival detection circuit 15B detects this via the terminal 5A, and supplies the control circuit 17 with an arrival signal 18E.
The control circuit 17 refers to station arrival settings (not shown). For example, if the key telephone 2 is set to generate a ring tone when an incoming call is received on the central office line 6, the other key telephones will transmit downlink data indicating the line status, while the button In addition to this, the telephone 2 transmits downlink data 18D for activating the calling speaker 29. This downlink data reaches the serial/parallel converter 27 via the above-mentioned path, and the converted data causes the calling speaker 29 to ring and the line display element for the office line 6 to blink at a cycle of 1 Hz to effect a call.

When the operator of the button telephone 2 responds to this call, he or she raises the handset 21, puts it off-hook, and operates the line selection button corresponding to the office line 6 whose display is blinking. As a result, a voice path similar to that described for the central office line transmission is constructed, and an incoming call response is performed. At this time, the control circuit 17 terminates the incoming call based on the uplink data 18A supplied from the key telephone 2.

In this way, when making and receiving calls from a central office line using a button telephone, the crosspoint circuit,
The insertion loss caused by the communication line transformer in the terminal circuit and the communication line transformer in the office line circuit is
This is compensated for by the amplifiers within each button telephone, so there are no call quality problems.

Next, returning to FIG. 1, an extension call using the standard telephone 5 will be explained. It is assumed that the standard telephone 5 is the calling telephone and the button telephone 2 is the called telephone. When the caller lifts up the handset of the standard telephone 5, the switch 41 in the interface circuit 4 is connected to the terminal circuit;
A line corresponding to the extension circuit 14 is automatically selected. As a result, standard telephone set 5 is connected to extension circuit 14 via terminal circuit 13 and crosspoint 16D in crosspoint circuit 16. After this, when the caller performs a dial operation on the standard telephone 5, the above-mentioned counting circuit performs counting, and the key telephone 2 is called based on this. When the called party responds to this call by operating the line selection button corresponding to the extension circuit 14, the button telephone 2 is connected in parallel to the extension circuit 14 via the terminal circuit 11 and the cross point 16A of the crosspoint circuit. . This allows extension calls between the two parties.

When making a central office line call using the standard telephone 5, the operator of the standard telephone 5, for example, lifts up the handset and then performs a hooking operation. This connects the switch 41 to the central office line side. As a result, the standard telephone set 5 is directly connected to the office line 6 via the switch 41, and communication over the office line becomes possible.

Parts that are the same as those in Figure 1 are designated by the same symbols in Figure 3.
The figure is for explaining in more detail the operation of a central telephone call using a standard telephone.

First, the extension call using the standard telephone 5 will be explained. When the caller lifts up a handset (not shown) and puts the standard telephone 5 in an off-hook state, the telephone current is supplied from the power supply 8 to the transformer 42, the break side of the transfer contact 41A of the relay 43A,
Telephone current flows through the standard telephone 5 through the break side of the transfer contact 41B of the relay 43B and the light emitting element in the photocoupler 44. The photodetection element in the photocoupler 44 detects this and supplies a detection signal to the off-hook detection circuit 45. The off-hook detection circuit 45 thereby detects that the standard telephone 5 is off-hook, and supplies the automatic line selection circuit 46 with a signal instructing it to make an extension call. It is assumed that the off-hook detection circuit 45 is configured to continuously generate an output even if the detection signal is momentarily interrupted for a predetermined time during hooking, which will be described later. Based on this, the line automatic selection circuit 46 uses a parallel-to-serial conversion circuit 47.
A signal equivalent to when the handset of a button telephone is raised and the extension button is pressed is given to the user. As a result, the data upstream path 7 within the connection cable 72
From the parallel-serial conversion circuit 47 to the main device 1 via 2A
Upstream data regarding the standard telephone 5 is supplied to a control circuit 17 (FIG. 2) within the telephone. This causes the control circuit 17 to connect to the crosspoint 16D in the crosspoint circuit.
(Fig. 1). As a result, the standard telephone 5 has a photocoupler 44, transfer contacts 41A, 41
Break side of B, transformer 42, connection cable 7
2, the terminal circuit 13 and the cross point 16D in the crosspoint circuit to the extension circuit 1.
Connected to 4. That is, as seen from the main device 1, the same operation as when a key telephone is connected via the connection cable 72 is performed, and as a result, the standard telephone 5 can make an extension call.

Next, the reception of an extension call to the standard telephone set 5 will be explained. The standard telephone 5 is given an extension number as a type of button telephone connected to the terminal circuit 13, similar to the button telephones connected to each terminal circuit. Therefore, each key telephone can make an extension call to the standard telephone 5 using this extension number.

At this time, similar to a call between key telephones, the control circuit 17 in the main device sends out downstream data for driving a call speaker. This downlink data is supplied to the serial/parallel conversion circuit 48 via a data downlink path 72C within the connection cable 72. Among the parallel data converted by the serial/parallel conversion circuit 48, the signal that makes the calling speaker ring is sent to the relay 43A.
supplied to As a result, the transfer contact 41A operates, and the incoming signal sent from the 16Hz incoming signal source 9 is transferred to the transfer contact 4 together with the power source 8.
It is supplied to the standard telephone set 5 via the make side of 1A and the break side of transfer contact 41B. As a result, the bell inside the standard telephone 5 rings and a call is made which is equivalent to a call made by a calling speaker.

When the operator of standard telephone 5 picks up the handset to answer the call, off-hook detection circuit 45 detects that standard telephone 5 is off-hook. Then, in the same manner as described above, upstream data is supplied to the control circuit 17 in the main device, and based on this, the main device 1 stops the calling operation. As a result, the relay 43A is restored, the bell stops ringing, and a voice path similar to that used for calling an extension is formed, allowing an extension call.

Next, the central telephone call using the standard telephone 5 will be explained. When the caller picks up the handset and takes the standard telephone set 5 off-hook, the operation of making an extension call as described above takes place. If the caller attempts to hook up in this state, the telephone current will be cut off momentarily. The photo coupler 44 detects this current change by a hooking detection circuit 49.
to communicate. The hooking detection circuit 49 thereby detects the hooking of the standard telephone 5 and supplies a detection signal to the automatic line selection circuit 46. When automatic line selection circuit 46 is supplied with this signal, it drives relay 43B and operates its transfer contact 41B in order to make a central line call. As a result, the standard telephone 5 is connected to the central office line 6 via the photocoupler 44 and the make side of the transfer contact 41B. At the same time, the automatic line selection circuit 46 gives the parallel/serial conversion circuit 47 a signal equivalent to when the handset of the key telephone is raised and the central office line button for the central office line 6 is operated. This signal is converted into serial data together with other signals, and then passes through the data upstream path 72A to the control circuit 17 (second
Figure).

Since telephone current is supplied from the central telephone line 6 to the standard telephone set 5 in the state of telephone communication over the central office line, the off-hook detection circuit 45 can continuously detect off-hook of the standard telephone set 5 through the photocoupler 44. Also, at this time, the main device 1, based on the uplink data supplied from the standard telephone 5 to the control circuit 17,
The same downlink data as when normal button telephones are using the central office line 6 is sent to all button telephones. As a result, all key telephones display the line as if the central office line 6 were being used by a normal key telephone.

Next, the holding of the central office line will be explained. When performing a hold operation during a telephone call on the central office line, the operator of the standard telephone 5 performs a hooking operation. When the hooking detection circuit 49 detects the first hooking, the automatic line selection circuit 46 creates a signal for calling the central office line as described above, but when the second hooking is detected in this way, it is regarded as a hold operation. , parallel-to-serial conversion circuit 47
A signal equivalent to that when a hold operation is performed on the central office line 6 is given to the station line 6. As a result, the office line 6 is held by the office line circuit 15. At the same time, the automatic line selection circuit 46 restores the relay 43B and disconnects the standard telephone 5 from the central office line 6. If the standard telephone 5 makes an extension call at this stage, the operator must pick up the handset again after setting the handset, but at the time of the second hooking operation described above, a signal for making an extension call is also sent from the automatic line selection circuit 46. By outputting the information, it is also possible to perform a hold operation and an extension call operation at the same time.

A re-response after the station line is put on hold can be performed by the same operation as when calling the station line. That is, the operator can connect the standard telephone set 5 to the central office line 6 by performing a hooking operation while the extension line is connected.

Finally, we will explain about receiving calls from the central office line. When a calling signal is sent from the central office line 6 to the key telephone device, an incoming call signal 18E is supplied to the control circuit 17 (FIG. 2) as described above. Based on this, the control circuit 17 generates a caller from the key telephone set for the central telephone, but does not perform the central telephone setting for the standard telephone.

Therefore, the operator of the key telephone receives the incoming call and transfers the call to the standard telephone 5 on hold. This is because, according to the circuit configuration of this embodiment, even if the operator of the standard telephone 5 raises the handset to receive an incoming call, the standard telephone will be connected to the extension circuit 14 as described above. .

As described above, according to the present invention, the standard telephone operates as if it were a button telephone via the interface circuit during extension calls, while it is directly connected to the office line via the relay contact during office line calls.
Therefore, there is no insertion loss within the main device during telephone calls over the central office line, and a suitable speech level can be maintained.

In the example, the standard telephone is connected to one central office line and one extension line, but by adding an appropriate automatic line selection circuit, it is possible to increase the number of lines that can be connected to both the central office line and one extension line. . However, if there are a plurality of connectable office lines, the circuit that connects the standard telephone to these office lines in a straight line becomes complicated, so it is practical to connect only one office line to one standard telephone. Note that it is natural that a plurality of standard telephones can be installed in the button telephone device.
In this case, it is of course possible to make extension calls between standard telephones.

Furthermore, if the button telephone device of the embodiment is equipped with a busy override function, the standard telephone does not have a speaker to transmit a third party's call during a call. It cannot be realized. Therefore, when the standard telephone is off-hook, the main device must inhibit the calling function to the standard telephone.

Furthermore, although the example does not explain the secret call function of a standard telephone when making a call to a central office line, if information on the use of a central office line is extracted from the downlink data sent from the standard telephone to the main unit, it will be possible to use other key telephones. It is possible to keep the conversation confidential.

Further, in the embodiment, it was not possible to set the standard telephone to receive calls from a central office line, but it may be possible to do so. That is, the incoming signal source 9 (third
If the intermittent cycle of the 16 Hz incoming signal sent from the 16Hz incoming signal sent from the 16Hz incoming signal (Fig. The arrival of an incoming signal from the line can cause the bell of a straight-line standard telephone to ring. Moreover, in this case, it is possible to distinguish between incoming calls from central office lines and incoming calls from extension lines by sound.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a button telephone device connected to a standard telephone, FIG. 2 is a block diagram of the button telephone and the main device, and FIG. 1 is a block diagram of an interface circuit for a standard telephone; FIG. 1... Main device, 2... Button telephone, 4... Interface circuit, 5... Standard telephone, 6...
Office line, 41A, 41B...transfer contact.

Claims (1)

[Claims] 1. Prepare a switching means that detects the standard telephone's hooking or a predetermined dialing operation and thereby switches the connection of the telephone line, and connects this switching means to the telephone line to which the standard telephone is connected,
One switching contact side of this switching means is directly connected to a predetermined central office line housed in the button telephone device, and the other switching contact side is connected to the main device of the button telephone device, so that this standard telephone can be connected to a central office line. A connection method for a standard telephone in a button telephone device, characterized in that during a call, the connection is made to the predetermined office line without going through the main device, while when making an extension call, the connection is made to an extension circuit within the main device.