JPH0697774B2 - Communication terminal - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a communication terminal device, and in particular, to a public switched telephone network or a switched network such as a private branch exchange (PBX), and voice communication, facsimile communication, data communication, etc. by an ordinary telephone. The present invention relates to a communication terminal device capable of communication other than voice.

2. Description of the Related Art For example, in a G3 facsimile recommended by the International Telegraph and Telephone Consultative Committee (CCITT), a conversation request switch is provided in a terminal device in order to enable a voice conversation with an operator. By operating this, the conversation request signal is transferred to the other party, and it is possible to shift from the facsimile communication to the voice conversation mode. As a conversation request signal, for example, CCITT Recommendation T.30, PIP (procedure interruption positive)
Signal, PIN (procedure interruption negative) signal, PRI-EOP (procedure interruption)
Signals are used.

Upon receiving this conversation request signal, the fax machine generates an operator call signal (e.g., ring a bell). For example, in the case of conversational communication before shifting to facsimile communication, when the calling station requests a conversation, the CED (called station identification) signal and DIS signal (digital identification signal) to be sent back to the automatic receiving station when it receives a call are transmitted. The calling operator does not operate the facsimile transmission switch even if he / she listens to the telephone on the side, and maintains the state as it is. On the other hand, the receiving station continues to retransmit the DIS signal for a predetermined time period, and when this time period elapses, an operator call signal is generated to prompt the incoming operator to respond. As a result, the voice conversation communication mode can be entered.

However, when the number of facsimiles becomes widespread, it is sometimes the case that a call is made from a non-facsimile telephone (general telephone) to an ordinary voice call by mistake, and the line is automatically connected to the automatic call reception facsimile device. is there. In that case, the caller often hears the CED signal or the DIS signal sent from the automatic termination facsimile terminal at the time of line connection and abandons the call. However, in the conventional automatic call receiving facsimile terminal device, even in the case of such abandonment, there is a transition from the transmission of the CED and DIS signals to the retransmission of the DIS and the generation of the operator call signal. Therefore, the operator of the terminating station will be called up to the telephone even if such an invalid call is made.

Aim The present invention, in the communication control at the time of line connection, for example, with the intention of making a call using a normal voice from a non-facsimile telephone (general telephone), the automatic call reception facsimile terminal is erroneously received and the line with the automatic facsimile terminal is connected. In such a case, avoid the situation where the called station operator is called by an invalid call due to abandonment of the called party, and call the called station operator only when the called party wants to make sure that the calling party wants a telephone call. It is an object of the present invention to provide a communication terminal device capable of

Configuration The configuration of the present invention will be described below based on an embodiment.

Referring to FIG. 1, in one embodiment of the present invention, a facsimile scanner 10 and printer 12 are connected to a telephone subscriber line loop 20 via a modulator / demodulator (MODEM) 14 and a line controller (NCU) 16. ing. The scanner 10 may be a normal operation device that operates a transmission document to input image information thereof, and the printer 12 is a normal image output device that reproduces the image information received from the line 20 as a visible image on a recording medium. is there.

The MODEM 14 is a normal modulator / demodulator that is connected to the scanner 10 and the printer 12 through a signal line 18 and performs signal processing necessary for transmission control of facsimile communication such as modulation / demodulation of facsimile signals, automatic line equalization, automatic gain control, and training. is there. These functions of the MODEM 14 are controlled by the control circuit 32 according to the progress status of the facsimile call.

The line side signal line 22 of the MODEM 14 is connected to the NCU 16. NC
U16 is a line switching device that selectively disconnects the line 20 between the connection line 26 to the telephone set 24 and the connection to the MODEM 14, and this disconnection is in response to the operation of the switch 30.
Under the control of. Therefore, by operating the switch 30, the line 20 is connected to the side of the scanner 10 and the printer 12 for facsimile communication, or the line 20 is connected to the side of the telephone 24 for conversation by voice. You can

The down line (reception line) 38 on the MODEM 14 side of the NCU 16 is connected to the signal sound detection circuit 40. The signal tone detection circuit 40 is a circuit that detects a specific service signal tone transmitted from the exchange of the central office to which the subscriber line 20 is connected. In the present embodiment, this particular service signal tone is, for example, an intermittent tone of 400 Hz for 1 second, and is used from the central office switch when, for example, the called subscriber or the line is busy or the calling subscriber is abandoned. Sent out.

The signal tone detection circuit 40 identifies such a specific service signal tone, and an analog or digital band pass filter is advantageously used. Of course, without providing the detection circuit 40 independent of such a control circuit 32, the control circuit
The signal sound detection function may be realized by a program of the processing system constituting 32. In any case, the specific signal tone sent from the central office and received on the line 20 must be clearly distinguishable from various facsimile control signals sent from the partner station and received on the line 20 for transmission control. Good.

The control circuit 32 is a control device that controls the NCU 16, the MODEM 14, the scanner 10, the printer 12, and the like, and thereby performs line control and transmission control as a transmitting station or a receiving station of the present device. Advantageously, it is realized by a processing system such as a microcomputer. Of this control, the operation flow for executing the function related to the present invention is the second.
As shown in the figure.

In connection with this, the control circuit 32 has a timer function, which sets a predetermined time, for example, a time-out period of about 12 seconds. During this period, the called station will
This is to count and monitor the time until the DCS signal (digital command signal) is returned as a predetermined control signal from the transmitting station after the (called station identification) signal is transmitted to the transmitting station. If this time period elapses without receiving a DCS signal, control circuit 32 will make an operator call.

The control circuit 32 is connected to a sounding device 44 including, for example, a piezoelectric element, a bell or a buzzer. In this embodiment, this produces an audible signal such as an operator call.

By the way, in the case of a normal call of a facsimile, as shown in FIG. 3, a selection signal SS such as a dial pulse is transmitted from the telephone 24 of the transmitting station Tx to the central office CO, and the receiving station Rx corresponding to it is sent to the central office CO. Selected, ringing signal towards this
RING is sent. Then, the NCU 16 of the terminating station Rx detects the ringing signal RING, whereby the control circuit 32 identifies the incoming call (step 100 in FIG. 2).

Then, the control circuit 32 of the receiving station Rx controls the NCU 16 to invert the loop of the subscriber line 20, and the line 20 is extended to the transmitting station Tx. Therefore, the control circuit 32 of the receiving station Rx sends a CED (callee identification) signal to the transmitting station Tx via the MODOM 14 and sets the above-mentioned timer (102). The time period T of this timer is set to a time period of about 12 seconds, for example.
When the caller hears this CED signal from the handset of the telephone set 24 and operates the switch 30 to the MODEM 14 side (SWM in FIG. 3), the control circuit 32 of the transmitting station Tx controls the NCU 16 to connect the line 20 to the MODEM 14 side.
Connect to the side.

Following the CED signal, the control circuit 32 of the receiving station Rx sends DIS (digital identification signal) (104). In response to this, the control circuit 32 of the transmitting station Tx returns DCS (digital command signal) (106). Thus, the subsequent facsimile procedure is advanced (108).

If the caller is a facsimile call and the caller requests a voice conversation with the called party before the facsimile communication starts, the caller holds the switch 30 on the side of the telephone 24 even if the caller hears the CED signal and the DIS signal. I'll do it. The control circuit 32 of the terminating station Rx continues to transmit the DIS signal toward the originating station Tx at a predetermined time interval of, for example, about 3 seconds until the above-mentioned timer times out (104). When it times out (114), the receiving station Rx
The control circuit 32 activates the sounding element 44 to generate an operator call signal (OPC in FIGS. 2 and 116 and FIG. 4). This transmission control flow is shown in FIG. Then, if the operator of the receiving station Rx operates the switch 30 to the telephone 24 side (see FIG. 4, SW
S) and thereafter, conversation communication 200, 202 can be performed.

For example, if the caller makes a call from a general telephone to a facsimile terminal instead of a facsimile machine, or if the call is received at the receiving station Rx due to an incorrect connection to the facsimile terminal, or even if it is a facsimile call, a conversation request is made. When the caller goes on-hook by hearing the CED signal or the DIS signal as in the case of abandoning the call (ONF in FIG. 5), the central office CO detects the loop break 210 of the subscriber line. When the central office CO is the last party release type switching system, the central office CO responds to this while holding the line and responds to this by the recovery signal sound, for example, the busy tone used as the service signal sound to the receiving station Rx.
Send T, or busyton.

Since the conventional automatic call receiving facsimile apparatus does not detect such a service signal tone, an operator call is made at the time-out point even though the caller has already abandoned the quasi-normal call. . This is shown by OPC in FIG. In this case, even if the call switch was operated at the receiving station Rx, the signal sound could only be heard from the handset.

In this device, such a service signal sound (in this example, an audible sound of 400 Hz for 1 second) is detected by the signal sound detection circuit 40 of the receiving station Rx (110). In response to this, the control circuit 32
Disconnects the loop of the line 20 through the NCU 16 and restores the idle state (112). Since this restoration processing is performed before the time limit T of the timer has elapsed, the control circuit of the receiving station Rx
32 does not drive the sounding element 44.

Although the present invention has been described with reference to particular embodiments, it is not limited thereto. For example, a case has been described where the facsimile connection is provided by the central office of one stage, but of course, a plurality of relay exchanges may be provided between the originating and terminating stations. Further, it is not necessarily a public line network, and may be a connection in a PBX network, for example.

Effect According to the present invention, in the communication control at the time of line connection, only when neither the busy tone nor the data transmission signal is detected within a predetermined period after the line connection, the sounding means is driven and the operator calling is started. Therefore, if there is an invalid call in which the other party abandons the call within the above-mentioned predetermined period, a busy tone is detected and the operator call is not made. It is possible to eliminate the situation where the operator of the above is called to the telephone.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment in which a communication terminal device connected to a switching network according to the present invention is applied to a telephone facsimile, and FIG. 2 is a flow chart showing the operation of the device of the embodiment shown in FIG. FIGS. 3 to 5 are transmission control flow charts showing the transmission control flow in the embodiment of FIG. 1. FIG. 3 is a normal facsimile call, FIG. 4 is a facsimile conversation request call, and FIG. 5 is a general call. Shows the case where a call arrives at a facsimile terminal and is abandoned halfway. Explanation of symbols of main parts 14 …… MODEM 16 …… Line control device 20 …… Line 24 …… Telephone 30 …… Switch 32 …… Control circuit 40 …… Signal tone detection circuit 44 …… Sound element

Claims (1)

[Claims] 1. A communication terminal device connected to a line and capable of selectively executing data transmission by a data terminal and a call by an operator, a control means, and a line control means for controlling connection and disconnection of the line. Timing means for measuring whether or not a predetermined period has elapsed, control signal detection means for detecting a predetermined control signal transmitted from the partner data terminal, and busy tone detection means for detecting a busy tone sent from the exchange. , A notification means for calling an operator, and after the line connection by the line control means, the control means,
When the measurement by the timer is started and the predetermined control signal is detected within the predetermined period from the start of measurement, the data transmission procedure is advanced, while the busy tone is detected within the predetermined period from the start of measurement. In this case, the line control means is controlled to disconnect the line, and only when the predetermined period elapses without detecting either the busy tone or the predetermined control signal, the notification means is driven to call the operator. A communication terminal device, characterized in that: