JPH06152796A - Communication equipment containing branch telephone connecting device - Google Patents

Abstract

PURPOSE:To provide a communication equipment which can secure the branch connection to the line of a telephone set. CONSTITUTION:A branch telephone set and a facsimile equipment are connected in parallel to a telephone line. The off-hook/on-hook operations are carried out at a voltage monitoring part. Then the incoming is confirmed (S2) and the branch telephone set is hooked off (S3). When the incoming is equal to the facsimile and the calling is through, the branch telephone set is hooked on (S4). Then the facsimile equipment is connected to the line (S5) when the on-hook state of the branch telephone set is detected. Thus the facsimile procedure is started (S6).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device connected to a telephone line in parallel with a telephone, that is, a communication device provided with a branch telephone connection device.

[0002]

2. Description of the Related Art Conventionally, a telephone line has been used as a communication line for data communication, for example, a facsimile machine or a telex, in addition to a telephone. With the spread of data communication, as facsimile machines are widely used in general households as well, a dedicated telephone line for data communication is not prepared, and a single telephone line is used for both telephone and facsimile communication. The use of it is increasing.

Both facsimile machines and telex machines perform data communication after establishing communication according to a similar protocol. Here, the relationship between the telephone and the communication device will be described by taking a facsimile device as an example. Simply connecting the telephone and the facsimile device in parallel to the telephone line will cause the facsimile device to start responding when there is an incoming call, regardless of whether the telephone is off-hook.
Since the communication sound of the protocol is received, the facsimile device cannot be branch-connected to the telephone.

Conventionally, an auxiliary telephone or a slave telephone can be connected to a facsimile machine so that telephone and facsimile communication can be carried out by an NCU (network control circuit) of the facsimile machine. As the communication mode, generally, a manual call receiving mode and an automatic call receiving mode are known. In the manual call receiving mode, an incoming call from the telephone is prioritized, and when the incoming call is a facsimile, the operator off hook switches to the facsimile reception. There are various types of automatic call receiving modes. When a call is received, a facsimile machine monitors a facsimile identification signal, for example, a CNG signal, and if a CNG signal is detected within a predetermined time, a facsimile procedure is performed. However, when the CNG signal is not detected, the telephone is placed under the control of the facsimile apparatus, such as calling the attached telephone and the slave telephone.

Therefore, a person who has an existing telephone is
If an attempt was made to install a facsimile device by sharing the same line, it was necessary to install the facsimile device in the place where the telephone was placed and use the attached telephone instead of the existing telephone. In order to install the facsimile device in a place different from the place where the telephone is placed, there is a problem that the line of the child telephone must be extended and the child telephone must be purchased separately.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to realize a communication device capable of branch connection to a telephone line.

[0007]

SUMMARY OF THE INVENTION The present invention is a communication device branch-connected to a telephone on a telephone line, which has off-hook detecting means for detecting a change in the line current of the telephone line. It is characterized in that the communication procedure is started when the on-hook of the telephone is detected after the off-hook of the telephone is detected.

[0008]

According to the present invention, the off-hook / on-hook of the branch telephone can be detected independently of the operation of the communication device by using the off-hook detecting means for detecting the change in the line current of the telephone line. Further, since the communication procedure is started when the off-hook of the branch telephone is detected after the off-hook of the branch telephone is detected, the transmitting side does not send an unpleasant signal tone.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of essential parts of an embodiment in which the present invention is applied to a facsimile machine. In the figure, 1 is a line, 2 is a branch telephone, 3 is a facsimile connection terminal,
Reference numeral 4 is a facsimile device, 5 is a slave telephone connection terminal, 6 is an auxiliary telephone connection terminal, 7, 8 are off-hook detection circuits, 9,
Reference numeral 10 is a changeover switch, 11 and 12 are transformers, 13 is a modem, 14 is a dial circuit, 15 is an incoming call detection unit, 16 is a voltage monitoring unit, 17 is a ringing voltage generation unit, 18 is a display unit, 1
9 is an operating unit, 20 is a ROM, 21 is a RAM, 22 is a timer unit, 23 is a document reading unit, 24 is a recording unit, 25 is a speaker, 26 is a silence detecting unit, 27 is a CNG detecting unit, 28 is a DTMF detecting unit. , 29 are main control units (CPU).

The branch telephone 2 is connected to the line 1, and the line 1 to which the branch telephone 2 is connected is
The facsimile machine 4 is connected in parallel at the connection terminal 3. The modem 13 of the facsimile device 4 is connected to the line 1 via the transformer 11 and the changeover switch 9. The slave telephone and the accessory telephone are connected to the slave telephone connection terminal 5 and the accessory telephone connection terminal 6. With the changeover switch 9,
The connection of the line 1 to the incoming call detection unit 15 and the modem 13 is switched, and the changeover switch 10 switches the slave telephone and the attached telephone to the line 1 or the ringing voltage generation unit 17. The ringing voltage generator 17 is configured as a DC voltage source,
When the auxiliary telephone and the slave telephone are disconnected from the telephone line, a DC voltage is supplied to them so that the off-hook detection circuits 7 and 8 can detect off-hook / on-hook. The changeover switches 9 and 10 are controlled and changed over by the CPU 29.

The dial circuit 14 sends a dial pulse corresponding to the telephone number of the other party at the time of calling. The incoming call detection circuit 15 is composed of a photo coupler and has an LED
Is connected to the line 1 side, and the ON / OFF state of the phototransistor is monitored by the CPU 29 at a predetermined sampling cycle, whereby the ringing signal (16 Hz) of the exchange arriving on the line 1 can be detected. . The off-hook detection circuits 7 and 8 detect the off-hook states of the attached telephone and the slave telephone, respectively, and the detection results are monitored by the CPU 29. The transformer 12 transmits the tone signal from the line 1 from the transformer 12 to the modem 13 when the changeover switch 9 is switched to the incoming call detection unit 15 side.

The voltage monitoring unit 16 detects the voltage of the line 1. When the branch telephone 2 goes off-hook when an incoming call is received on the line 1, the voltage of the line 1 drops.
On-hook can be detected. The display unit 18 displays the state of the facsimile device and the input data from the operation unit 19. The document reading unit 23 reads a transmission document or a copy document, and the recording unit 24 prints out a reception document or copy data. The speaker 25 outputs a pseudo bell sound and a warning sound. Silence detector 26, CNG detector 27, DTM
The F detector 28 detects the tone signal from the line 1. A main control unit (CPU) 29 controls the entire facsimile device based on a control program and fixed data stored in the ROM 20.

FIG. 6 shows a concrete example of the voltage monitoring unit 16.
In the figure, 1 is a line, 2 is a branch telephone, 31 is a voltage detection unit, 32 is a voltage storage unit, and 33 is a comparison unit. The voltage detection unit 31 converts the detected line voltage into a digital value. The voltage storage unit 32 stores the output data of the voltage detection unit 31 according to a command from a CPU (not shown). The comparison unit 33 compares the output data of the voltage detection unit 31 with the voltage storage unit 32.
The H or L signal is output according to the comparison result compared with the stored value of. The output signal is transmitted to a CPU (not shown). For example, when there is an incoming call, the DC voltage of line 1 is 4
The voltage is about 8V, and the voltage detection unit 31 converts the detected voltage into a digital value. This digital value is stored in the voltage storage unit 32 as the reference voltage of the comparison unit 33. The DC voltage of the line 1 when it is off-hook is, for example, about 5V. Therefore, if the branch telephone 2 is off-hook after the incoming call, the comparing unit 33 detects that the difference exceeds the threshold value, and the branch telephone 2 Can detect off-hook. The threshold value may be selected according to the situation to be detected. For example, when the lines are closed in both the facsimile unit and the branch telephone, a small voltage change when the branch telephone 2 is hooked on can be detected with a different sensitivity from a large voltage change when the telephone is off hook. it can. The voltage storage unit 32 does not necessarily need to store the data from the voltage detection unit 31. As mentioned above, 48V and 5V
When detecting a situation with a large difference, an intermediate voltage value may be stored. Further, even if the analog circuit such as a differential amplifier circuit is used corresponding to the comparison unit, the voltage detection unit detects the analog voltage and compares it with the comparison voltage, the voltage monitoring unit may be configured by the analog circuit. Good.

As described above, the voltage monitoring unit detects the line state due to off-hook / on-hook of the branch telephone, and can be detected by the off-hook detecting circuit 7. It is also possible to detect the voltage change within 100 msec, for example, in order to detect the differential change of the line voltage. Alternatively, the line current may be detected. That is, when an incoming call is received and the branch telephone is on-hook, the line current is small. If the branch telephone is off-hook, the line current increases. Therefore, the off-hook / on-hook of the branch telephone can be detected by directly detecting the line current. The magnetic field due to the line current may be detected using a Hall element or the like. However, in the case of detecting the line current, the detector must be provided on the station side of the branch telephone, so it is necessary to consider the arrangement of the detector.

FIG. 2 is a flow chart for explaining an embodiment of the operation of the facsimile apparatus of FIG. The branch telephone priority mode is selected and the flow starts. As described above, the line voltage is monitored, and the off-hook / on-hook of the branch telephone 2 is detected from the change, so that the line voltage before the incoming call is detected in S1 and the value is stored in the RAM 21. Keep it. Then, S2
Go to and detect the bell sound. When there is no incoming call,
The loop from S2 to S1 is repeated to enter the standby state. When there is an incoming call, the output of the incoming call detecting unit 15 is transmitted to the CPU 29, a bell sound is detected, and the process proceeds from S2 to S3. In this state, the branch telephone 2 sounds a bell and repeats the loop from S3 to S2. When branch telephone 2 is taken off-hook, the voltage on line 1 drops. The voltage monitoring unit 16 stores the detected voltage value in the RAM 21.
The off-hook is detected by comparing with the voltage value stored in step S4, the loop is exited, and the process proceeds to step S4. The detected voltage value is stored in the RAM 21. When the sub-phone or the attached telephone is off-hook, a call is made on the sub-phone or the attached telephone, and the off-hook detection circuit 7
Or in 8 the off-hook of the sub-phone or attached telephone is C
Although it is detected by the PU 29, its description is omitted.

When the branch telephone 2 is taken off-hook,
The branch telephone can make a call, and if the incoming call is a call, the call is made. Next, in S4, the voltage monitoring unit 16 monitors the on-hook of the branch telephone 2. If the call ends or if the incoming call is a facsimile, the branch telephone 2 is hooked on.

When the rise of the line voltage due to the on-hook of the branch telephone 2 is detected, the process proceeds to S5 and the CPU 29
The changeover switch 9 is changed over in response to the command, and the transformer 11 closes the line. Since the time from the on-hook of the branch telephone 2 to the closing of the line by the facsimile machine is short, the exchange on the office side does not drop during this time. Then, in step S6, a shift to the facsimile procedure is performed, and at the end of the procedure, the process returns to the start. Therefore, the facsimile reception after the call is completed by the manual transmission can be performed, and even when the incoming call is the facsimile, the facsimile reception can be immediately started by the on-hook of the branch telephone 2 as described above.

When the procedure shifts to the facsimile procedure, the receiving side sends out CED and DIS. CCITT T. Three
According to the standard of 0, the maximum transmission of CED and DIS is 30 to 4
It is necessary to do it for 0 seconds. In the present invention, CED and DIS can be sent once or twice. According to the present invention, when the branch telephone is off-hook when it is found to be a facsimile and the procedure is shifted to the facsimile procedure, the facsimile procedure can be started without a problem even if the number of CED and DIS transmissions is small. In addition, even if the call ends and the branch telephone goes off-hook by receiving an incoming call only, not by facsimile, the line can be opened promptly.

When the incoming call is only a call, the procedure proceeds to the facsimile procedure after the call is ended. In the case of a call, the sender is also on-hook with the end. Therefore, even if the facsimile device 4 executes the facsimile procedure thereafter, there is no problem.

FIG. 3 is a time chart for explaining the incoming call state. When there is an incoming call (CI) from the line (LINE), the line voltage drops when the branch telephone goes off-hook. The line voltage then rises due to the on-hook of the branch telephone. As shown in the FAX loop, when the rise of the line voltage is detected, the facsimile machine closes the line and shifts to the facsimile procedure.

FIG. 4 is a flow chart for explaining another embodiment of the operation of the facsimile apparatus of FIG. The branch telephone priority mode is selected and the flow starts. The same steps as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. In the above-described first embodiment, the line is closed by the facsimile machine when the on-hook of the branch telephone 2 is detected. In this example,
In S3, when the branch telephone 2 is off-hook, the changeover switch 9 is changed over to change the transformer 1
The line is closed at 1 so that the line is closed by the facsimile machine. However, the facsimile procedure does not proceed at this stage.

When the on-hook of the branch telephone 2 is detected in S4, the process proceeds to S6 and the facsimile procedure is performed. In this case, since the line is closed by the facsimile side before the on-hook of the branch telephone 2, the branch telephone 2 and the facsimile device 4 are connected to the line 1 in parallel. In this state, the line voltage has a lower value. When the branch telephone 2 is hooked on in this state, only the facsimile device is connected to the line 1, and the line voltage is higher than that when the parallel load is applied. Therefore, the on-hook of the branch telephone 2 in this case can also be detected by the voltage monitoring unit 16.

In the case of the embodiment shown in FIG. 4, there is no temporary disconnection of the line as shown in the time chart of FIG. Also, F
When the branch telephone goes on-hook, as shown in the AX loop, the fax procedure is initiated. Therefore, no facsimile signal tone is sent to the line until the branch telephone is hooked up.

In the above description of the embodiment, the branch telephone priority mode has been described, but it goes without saying that an automatic reception mode or a manual reception mode which has been conventionally used may be additionally provided so that this can be selected. is there.

[0025]

As is apparent from the above description, according to the present invention, since a facsimile apparatus can be connected in parallel to a branch telephone, regardless of the installation position of the telephone, the facsimile apparatus can be operated without consideration of its wiring. You can freely set the location. Then, since the facsimile procedure is not performed before the branch telephone is off-hook and then on-hook, when the incoming call is a call,
The effect is that the transmitting side does not hear an unpleasant facsimile signal sound.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an embodiment in which the present invention is applied to a facsimile device.

2 is a flow chart of an embodiment of the operation of the facsimile apparatus of FIG.

FIG. 3 is a time chart illustrating the incoming call state of FIG.

4 is a flowchart of another embodiment of the operation of the facsimile apparatus of FIG.

FIG. 5 is a time chart explaining the incoming call state of FIG.

FIG. 6 is a block diagram of a specific example of a voltage monitoring unit.

[Explanation of symbols]

 1 Line 2 Branch Telephone 3 Facsimile Connection Terminal 4 Facsimile Device 16 Voltage Monitoring Section 26 Silence Detection Section 27 CNG Detection Section 29 Main Control Section (CPU)

Claims (1)

[Claims] 1. A communication device branch-connected to a telephone on a telephone line, comprising off-hook detection means for detecting a change in line current of the telephone line, the off-hook detection means after detecting off-hook of the telephone. A communication device equipped with a branch telephone connection device, wherein a communication procedure is started when an on-hook of the telephone is detected.