JP2640464B2 - Facsimile machine for both internal and external lines - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an internal / external line facsimile apparatus that switches and connects to both an extension from a private branch exchange and an external line which is a subscribed telephone line.

[Prior art] In a business office equipped with a private branch exchange, an extension is used for communication within the business office and a public line network is used for communication with other business offices. 2. Description of the Related Art An internal / external line facsimile apparatus which can be switched and connected to both an external line and an external line is known.

When making a call to another business office with such a facsimile machine, the outside line is selected and the call is processed.At this time, the subscriber's telephone line is disconnected due to an accident, or the facsimile machine is connected to the line. If the plug jack is disconnected, the transmission process is not performed.

In general, when a call is made from an extension of a private branch exchange, for example, if "0" is added to the first digit of the dial number and the telephone number is dialed, it is possible to make a call to an outside line. Therefore, when there is an abnormality on the subscriber telephone line side as in the above case, it is possible to make a call from an extension to an outside line.

However, the conventional extension / external line facsimile machine has a problem that the calling process is not performed in such a case.

[Purpose] It is an object of the present invention to solve the above-mentioned disadvantages and to provide an extension / external line facsimile apparatus which performs a calling process even when an abnormality occurs on a subscriber telephone line side.

[Configuration] For this reason, in the present invention, when a predetermined tone signal is not detected from the line when an outside line is transmitted from the subscriber telephone line side, the line is switched to the extension side and the call is transmitted to the public line network via the private branch exchange. is there.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a facsimile system according to one embodiment of the present invention. In FIG. 1, an external line 3, which is a subscribed telephone line forming a public line network 2, and an extension line 5 of a private branch exchange 4 are connected to the facsimile apparatus 1. An extension telephone 6 and another facsimile machine 7 are connected to the private branch exchange 4, while an office line 8 from the public line network 2 is connected to the private branch exchange 4.
Is connected.

In the facsimile apparatus 1, the scanner 101 reads an image of a transmission original at a predetermined resolution, and the plotter 102 records and outputs a received image at a predetermined resolution.

The operation display unit 103 is composed of a display unit having a large degree of freedom for displaying various operation keys and operation guidance information, and is used by an operator to operate the facsimile apparatus. Reference numeral 104 denotes a unit having a function of encoding and compressing image data and a function of decoding the encoded and compressed image data into original image data.

The incoming call detection circuit 105a detects an incoming call from the outside line 3, and the incoming call detection circuit 105b detects an incoming call from the extension line 5. The switching circuit 106 selects one of the external line 3 and the internal line 5, and the NCU (network control unit) 107 performs a calling or receiving operation for the selected line. The tone detection circuit 108 detects a response signal returned from the public line network 2 or the exchange 4 in a calling operation.

The modem 109 transmits and receives a transmission procedure signal, modulates and demodulates image information, and transmits and receives the image signal. The communication control unit 110 includes the switching circuit 106, the NCU 107, and the modem 10
9 to execute a predetermined transmission control procedure. The system control unit 111 controls the above-described circuit and causes the facsimile apparatus 1 to execute a predetermined transmission / reception operation.

The facsimile system according to the present embodiment has the above configuration. When transmitting an image using the facsimile apparatus 1, the operator sets a document to be transmitted on the scanner 101, and then designates an extension transmission or an external transmission by operating the operation display unit 103. At the same time, the user inputs a destination telephone number and performs a predetermined calling operation.

Here, assuming that an outside line is specified,
It operates as shown in FIG. That is, the switching circuit 106
Is switched to the outside line 3 side, and the NCU 107 is connected to the outside line 3 and seizes the line (process 201).

Next, the tone detection circuit 108 detects a dial tone (dial tone) from the line (process 202). When a dial tone is detected (Y in step 202), the NCU 107 sends a selection signal, which is a destination telephone number, to the line (step 20).
3). Thereafter, the tone detection circuit 108 starts the operation of detecting a ringback tone (ringing tone) and a busy tone (busy tone) from the line (process 204 and process 205), and repeats this detection operation for a certain period of time, for example, 20 seconds ( From the N of the process 204 to the process 205, from the N of the process 205 to the process 206, and from the N of the process 206 to the process 204).

If a ringback tone is detected during this time (processing 20
(4) Y) Next, a CED signal, which is a response signal from the destination facsimile machine, is detected for a certain period of time (from processing N to processing 208, from processing N to processing 207).

If the line and the destination facsimile are normal, the destination facsimile responds and sends a CED signal (Y in process 207).

At this time, the system control unit 111 controls each unit, and transmits image information of the document set on the scanner 101 according to a predetermined procedure (process 209).

On the other hand, if the CED signal is not detected within a certain period of time (Y in step 208), it is considered that there is a failure in the telephone line network, that the other party facsimile machine is not connected, or that the device has failed. At this time, an error message indicating that the other party does not respond is displayed on the display unit of the operation display unit 103 (process 210), and the process is stopped. When a busy tone is detected after the selection signal is transmitted (Y in process 205), a message of "busy" is displayed (process 210), and the process is temporarily stopped.

By the way, in addition to the above abnormal state, for example, when the connection between the facsimile machine 1 and the outside line 3 is disconnected or the line is disconnected due to a lightning strike on the line, the dial tone is not detected (N in process 202). Further, there is a case where a ringback tone or a busy tone is not detected within a predetermined time due to a failure on the exchange side of the central office (Y in process 206).

In such a case, an error message indicating an external line abnormality is displayed on the operation display unit 103 (process 211), and the switching circuit 106 is switched to the extension 5 side (process 212). Next, the NCU 107 captures the line on the extension 5 side, and a dial tone is detected in the same manner as described above (process 213). Here, when a dial tone is detected (Y in process 213), the selection signal is output in accordance with the dial operation procedure for the outside line set in the private branch exchange 4, such as "0" + the destination telephone number. Is sent out (process 214). Thus, the call is transmitted to the outside line via the private branch exchange 4.

Thereafter, as described above, when a ringback tone is detected (Y in process 215), a CED signal is detected next (process 20).
7) If the signal is received, a predetermined transmission process is executed (process 209).

As described above, in the case where the line of the external line 3 is disconnected or disconnected, the transmission processing can be performed by the transmission from the internal line 5 side.

On the other hand, when the CED signal is not received (Y in step 208),
When no dial tone is detected (N in process 213),
Alternatively, if neither a ring back tone nor a busy tone is detected within a certain time after the selection signal is transmitted (N in processes 215 and 216 and Y in process 217), as in the case of the outside line transmission, an error in the other party's facsimile machine or line occurs. Therefore, an error message is displayed (process 210), and the transmission process is stopped. Also, in the case of the busy tone (Y in step 214), the processing is temporarily stopped similarly.

In the above, the processing in the case where the operation of transmitting an outside line has been performed has been described.
6 is switched from the beginning to the extension 5 side, a selection signal indicating the extension telephone number is transmitted, and the same processing as the processing 213 and thereafter in FIG. 2 is executed. As a result, image information is transmitted between extensions.

On the other hand, when receiving the image information, the incoming call detection circuits 105a, 105b
, The incoming call is detected, and the switching circuit 106 is switched to the incoming line. Thereafter, a predetermined receiving process is performed.

As described above, according to the present embodiment, when a call is made from the outside line 3 and a predetermined tone signal is not transmitted from the line,
An external line is transmitted from the extension 5 via the private branch exchange 4. Thus, even in the case of a failure such as a disconnection of the external line itself, which is a subscribed telephone line, transmission processing can be performed by calling from the internal line.

In the above embodiment, the failure of the outside line is detected only by the tone signal. However, the failure can be determined in more detail by detecting the reversal of the line voltage at the time of the incoming call.

[Effects] As described above, according to the present invention, when a predetermined tone signal is not detected when an external line is transmitted from a subscriber line, the external line is transmitted from the internal line via the private branch exchange. Even if there is an abnormality such as a disconnection on the side, predetermined transmission processing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a facsimile system using a facsimile apparatus for both internal and external lines according to an embodiment of the present invention, and FIG. 2 is a flowchart showing an operation of the facsimile apparatus when transmitting an external line. 1,7 ... Facsimile machine, 2 ... Public line network, 3 ...
Outside line, 4 ... Private branch exchange, 5 ... Extension line, 6 ... Telephone,
101: scanner, 102: plotter, 103: operation display unit, 104: encoding / decoding, 105a, 105b: incoming call detection circuit, 106: switching circuit, 107: NCU, 108: tone Detector circuit 109 Modem 110 Communication controller 111 System controller

Claims (1)

(57) [Claims] An internal / external facsimile apparatus for connecting an extension of a private branch exchange to an external line which is a subscribed telephone line forming a public line network and arbitrarily selecting one of the two types of lines to perform facsimile transmission. An external line transmitting means for selecting the above-mentioned external line and executing a predetermined transmitting process during a transmitting operation using a public line network, and an external line for detecting an abnormality of the external line by detecting a tone signal from the line in the transmitting process. Abnormality determining means, and external line via external line transmitting means for switching to the extension side when an external line abnormality is determined, and executing predetermined transmission processing from the extension to the public line network via the private branch exchange. Facsimile machine for both internal and external lines.