JPH0522551A - Facsimile signal transmission system - Google Patents

Abstract

PURPOSE:To evade the collision of a response signal for a facsimile signal and a retransmitted facsimile signal on a digital line in a facsimile signal transmission system performing the transmission of the facsimile signal via the line. CONSTITUTION:This system is provided with facsimile equipment 11 transferring an analog facsimile signal and retransmitting the same signal as a response signal for the facsimile signal when the response signal is not received within a prescribed time and a transmitter 13 taking an interface between the facsimile equipment 11 and a digital line. The system is constituted by being provided with a transmission start control means 15 monitoring a facsimile signal transmitted by the facsimile equipment 11 for which the interface is taken and starting the transmitter 13 performing the transmission processing of the response signal by defining the detection time of the facsimile signal as a starting point within the time when the processing time of the interface, the transmission delay time of a digital line and the signal length of the response signal are eliminated from a prescribed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile signal transmission system for transmitting a facsimile signal according to a predetermined control procedure in a transmission device which interfaces an analog signal type facsimile device and a digital line.

[0002]

2. Description of the Related Art GIII facsimile machines are widely used because of their high speed transmission and their direct connection to existing subscriber lines by adopting a redundancy suppression coding system. A signal transmitted and received during communication by such a facsimile apparatus is an analog signal, but a transmission system has been proposed in which the signal is transmitted and received via a digital line (Japanese Patent Application No. 62-62).
-206940).

FIG. 8 is a diagram showing a configuration example of a conventional facsimile signal transmission system. In the figure, a facsimile device 81 ₁ is connected to one end of a digital line via a transmission device 82 _1, and the other end of the digital line is connected to a facsimile device 81 ₂ via a transmission device 82 ₂ .
Further, telephones 83 ₁ and 83 ₂ are connected in parallel to the facsimile devices 81 ₁ and 81 ₂ , respectively.

In such a system, for example, when a facsimile signal (command) is transmitted from the facsimile device 81 ₁ to the facsimile device 81 ₂ , the transmission device 82
₁ demodulates the facsimile signal using a modem,
It is converted into a digital signal and sent to the digital line.
The transmission device 82 ₂ remodulates the digital signal using a modem, converts it into an original analog signal, and supplies it to the facsimile device 81 ₂ . In addition, the transmission devices 82 ₁ and 82 ₂
Waits in a voice communication mode in which voice signals can be transmitted and received between the telephones 83 ₁ and 83 ₂ via a digital line in a state where facsimile communication is not being performed.

[0005]

By the way, in such a conventional system, there is a delay in processing such as modulation, demodulation, demultiplexing and the like performed by the transmission devices 82 ₁ and 82 ₂ and a transmission delay in a digital line. The facsimile signal sent by 81 ₁ (FIG. 9 (1)) is delayed and transmitted to the facsimile apparatus 81 ₂ (FIG. 9 (2)), and a response signal (response) to the facsimile signal (FIG. 9 (3)).
Similarly, there was a delay (Fig. 9 (4)). Further, the facsimile machine has a predetermined time (= 3) after transmitting the facsimile signal.
If the response signal is not received within the second second, the facsimile signal having the same content as the already transmitted facsimile signal is retransmitted (FIG. 9 (5)). Therefore, the retransmitted facsimile is transmitted between the facsimile device and the transmission device. In some cases, the transmission timing of the signal and the above-mentioned response signal substantially matched. In such a case, these two signals collided on the two-wire line connecting the facsimile device and the transmission device, and neither of them could be transmitted or received normally.

According to the present invention, the facsimile signal retransmitted by the facsimile apparatus and the response signal to the facsimile signal sent prior to the facsimile signal can be prevented from colliding on the line between the facsimile apparatus and the transmission apparatus. It is an object to provide a facsimile signal transmission system.

[0007]

FIG. 1 is a block diagram showing the principle of the present invention. According to the first aspect of the present invention, the facsimile device 11 transmits and receives an analog facsimile signal, and retransmits the same facsimile signal if a response signal to the facsimile signal is not received within a predetermined time, the facsimile device 11 and the digital line. In a facsimile signal transmission system including a transmission device 13 having an interface, a facsimile signal transmitted by a facsimile device 11 having an interface is monitored, and a detection time of the signal is used as a starting point from a predetermined time to a processing time of the interface and a digital signal. The transmission activation control means 15 is provided for activating the transmission processing of the response signal in the transmission device 13 within a time excluding the transmission delay time of the line and the signal length of the response signal.

According to a second aspect of the present invention, a facsimile apparatus 11 which transmits and receives an analog facsimile signal and retransmits the same facsimile signal when a response signal to the facsimile signal is not received within a predetermined time, a facsimile apparatus 11 and a digital apparatus. In a facsimile signal transmission system provided with a transmission device 13 that interfaces with a line, a facsimile device 11 that is interfaced
When the elapsed time from the time when the facsimile signal transmitted by the is detected is monitored and the elapsed time exceeds the predetermined time excluding the processing time of the interface, the transmission delay time of the digital line and the signal length of the response signal, A transmission regulation control unit 21 that regulates the transmission processing of the response signal performed by the transmission device 13 is provided.

[0009]

According to the first aspect of the present invention, when a facsimile signal is transmitted from the facsimile device 11 interfaced by the transmission device 13, the transmission start control means 15 detects the facsimile signal, and from the detection time point. Of the transmission device 1 when the elapsed time of
3 to start transmitting a response signal.

The transmission start timing is determined from the waiting time until the same facsimile signal is retransmitted when the transmission device 13 cannot receive the response signal.
Is set within the time excluding the interface processing time, the transmission delay time of the digital line, and the signal length of the response signal described above, the response signal described above and the retransmitted facsimile signal are transmitted by the transmission device 13 and the facsimile device 1.
There is no collision on the two-wire line connecting the 1 and 2.

In the second aspect of the invention, the transmission device 13
Facsimile device 1 interfaced by
When the facsimile signal is transmitted from 1, the transmission regulation control means 21 detects the facsimile signal and permits the transmission process of the response signal to the transmission device 13, and when a predetermined time has elapsed from the detection time, the transmission device is transmitted. 13 regulates the transmission of the response signal.

[0012] Such transmission restrictions include waiting time until the same facsimile signal is transmitted when the transmission device 13 cannot receive the response signal, interface processing time in the transmission device 13, transmission delay time of the digital line, and the above-mentioned. Since it is performed at the time when the time excluding the signal length of the response signal has elapsed, the facsimile signal retransmitted from the transmission device 13 and the response signal do not collide with each other in the same manner as in the first aspect of the invention.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 is a diagram showing a configuration example of a transmission device to which the present invention is applied.

In the figure, parts having the same configurations and functions as those shown in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted here. The facsimile device 81 ₁ and the telephone set 83 ₁ connected in parallel are connected to the facsimile device 81 ₂ and the telephone set 83 ₂ connected in parallel via the transmission device 31 ₁ and the digital line and the transmission device 31 ₂ . The transmission device 31 ₁ has a transmission unit 32 ₁
And a receiver 33 ₁ .

[0015] The configuration of the transmission device 31 _2,
Since it is the same as the transmission device 31 ₁ , its detailed configuration is omitted in FIG. 3, and in the following, the same reference numeral with the subscript “ ₂ ” is given to indicate each component corresponding to the transmission device 31 _1. , The description is omitted.

In the transmitter 32 ₁ , the facsimile device 81
₁ and the telephone 83 ₁ are connected to the A / D converter 34 ₁ , the demodulator 35 ₁ and the switching control unit 36 ₁ . A /
The output of the D converter 34 ₁ is connected to one input of the selector 38 ₁ via the voice encoder 37 ₁ . Demodulator 35
The output of ₁ is connected to the command reception processing unit 39 _1, the output of one of which is connected to the other input of the selector 38 _1. The other output of the command reception processing unit 39 ₁ is connected to the control input of the switching control unit 36 ₁ , and its output is given to the selection control input of the selector 38 ₁ . Selector 38
The output of ₁ is connected to the digital line.

Receiver 33₁Then, receive from digital line
The received signal is the voice decoder 40. ₁, Command transmission
Science Department 41₁And switching control unit 42₁Given to.
Speech decoder 40₁Output of the D / A converter 43₁Through
Selector 44₁Connected to one input. Coman
Transmission processing unit 41₁One output of modulator 45₁Through
Selector 44₁Is connected to the other input of
Fax machine 81 ₁And telephone 83₁Connected to
It Command transmission processing unit 41₁The other output of
Control unit 42₁Connected to the control input of the
44₁Select control input of.

The command reception processing section 39 ₁ of the transmission section 32 ₁ is connected to the command transmission processing section 41 ₁ of the reception section 33 ₁ . Hereinafter, referring to FIG. 3, the transmission device 31
The basic operation of ₁ and 31 ₂ will be described.

[0019] In the transmission unit 32 ₁ of the transmission device 31 _1, the switching control unit 36 ₁ judges whether or not in the facsimile communication by detecting the type of signal supplied from the facsimile apparatus, the determination result The corresponding selection signal is transmitted. The selector 38 ₁ responds to such a selection signal by
If the facsimile communication is not in progress, the voice encoder 37 ₁
Connect the output of the to a digital line. On the other hand, the receiving unit 33
_{At 1} , the switching control unit 42 ₁ sends a selection signal according to the type of signal given via the digital line. The selector 44 ₁ responds to such a selection signal by
D / A converter 43 ₁ when not in facsimile communication
Is connected to the telephone 83 ₁ . In such a state (voice communication mode), voice signals can be transmitted and received between the telephone 83 ₁ and the digital line.

Further, for example, when the facsimile device 81 ₁ sends a facsimile signal to the facsimile device 81 ₂ , in the transmission part 32 ₁ , the switching control part 36 ₁ detects the type of the signal given from the facsimile device 81 _1. Then, it is judged that the facsimile communication is in progress, and a selection signal corresponding to the judgment result is transmitted. Selector 38
₁ is a command reception processing unit 39 according to the selection signal.
Connect the output of ₁ to the digital line. On the other hand, the receiving unit 3
In 3 ₁ , the switching control unit 42 ₁ similarly sends a selection signal in response to a signal received from the facsimile apparatus 81 ₂ via the digital line. The selector 44 ₁ connects the output of the modulator 45 ₁ to the facsimile apparatus 81 ₁ according to the selection signal. During facsimile communication, the facsimile apparatus 81 ₁ 81 ₂ in this way, to send and receive facsimile signals to each other via a digital line.

FIG. 4 is a diagram showing an embodiment corresponding to the invention described in claim 1. In FIG. In the present embodiment, the characteristic configuration of the present invention is a command reception processing unit 39 ₁ (39 ₂ ) and a command transmission processing unit 41 ₁ (41 ₂ ), and the basic configuration of the transmission device is shown in FIG. Therefore, the description thereof is omitted here.

Regarding the correspondence relationship between the present embodiment and the block diagram shown in FIG. 1, the facsimile apparatus 81 ₁ corresponds to the facsimile apparatus 11, the transmission apparatus 31 ₁ corresponds to the transmission apparatus 13, and the command detection unit 51. ₁ and the command reception state determination unit 52 ₁ correspond to the transmission activation control means 15.

FIG. 5 is a diagram for explaining the operation of the embodiment corresponding to the invention described in claim 1. The operation of this embodiment will be described below with reference to FIGS. In the command reception processing unit 39 ₁ , the command detection unit 51 ₁ takes in a facsimile signal (command) (FIG. 5 (1)) given from the facsimile device 81 ₁ through the demodulator 35 ₁ and recognizes the reception completion. , A command reception completion notification is sent to the status determination unit 52 ₁ in the command transmission processing unit 41 ₁ , and the facsimile signal is sent to the digital line via the command relay transmission unit 53 ₁ (FIG. 5 (2)). State determining unit 52 ₁ controls the command transmitting unit 54 ₁ in response to the command reception completion notification, the command transmitting unit 54 ₁ starts the transmission of rapidly facsimile device 81 ₁ to the preamble signals under its control (Fig. 5 (3)).

Here, the preamble signal is added to the beginning of a binary code signal (including a response signal) transmitted / received between the facsimile apparatus 81 ₁ and the transmission apparatus 31 ₁ at a speed of 300 bps, and is used for frame synchronization. Is a flag sequence that is set.

On the other hand, the response signal to the facsimile signal sent in advance from the command relay transmitting unit 53 ₁ (Fig. 5 (4)) is given to the command relay-receiving unit 55 ₁ through the transmission apparatus ₃₁₂ and the digital line (Fig. 5 (5))
However, the control of the command transmission unit 54 ₁ described above is performed even before such a response signal is received.

When the response signal is received after starting the transmission of the preamble signal as described above ((6) in FIG. 5), the command transmission unit 54 ₁ sets the transmission time width of the preamble signal to the facsimile device 81 ₁ After securing a value equal to or larger than the minimum time width (= 1 second) that can be detected by, the response signal is sent to the facsimile apparatus 81 ₁ (FIG. 5 (7)).

The preamble signal is composed of a fixed bit pattern irrelevant to the contents of the subsequent response signal, and its transmission time width is as described above unless it is restricted by the sequence control procedure in the facsimile apparatus 81 ₁ . There is no problem if it is longer than the minimum time width.

As described above, in the facsimile device 81 ₁ ,
Compared with the conventional example, since the preamble signal is given earlier by a time substantially equal to the round-trip delay time of the transmission devices 82 ₁ and 82 ₂ and the digital line, the facsimile device 81 ₁ transmits the preamble signal before resending the facsimile signal. The subsequent response signal can be detected.

Therefore, on the two-wire line connecting the facsimile device and the transmission device, the facsimile signal and the response signal do not collide with each other due to the processing delay of the transmission device and the transmission delay of the digital line.

FIG. 6 is a diagram showing an embodiment corresponding to the invention described in claim 2. In FIG. In the present embodiment, the characteristic configuration of the present invention is a command reception processing unit 39 ₁ (39 ₂ ) and a command transmission processing unit 41 ₁ (41 ₂ ), and the basic configuration of the transmission device is shown in FIG. Therefore, the description thereof is omitted here. It should be noted that components having the same configurations and functions as those shown in FIG. 4 are designated by the same reference numerals, and description thereof will be omitted here.

Regarding the correspondence relationship between the present embodiment and the block diagram shown in FIG. 2, the facsimile device 81 ₁ corresponds to the facsimile device 11, the transmission device 31 ₁ corresponds to the transmission device 13, and the command detection unit 51. ₁ and the command reception state determination unit 61 ₁ correspond to the transmission regulation control means 21.

FIG. 7 is a diagram for explaining the operation of the embodiment corresponding to the invention described in claim 2. The operation of this embodiment will be described below with reference to FIGS. 3, 6 and 7. In the command reception processing unit 39 ₁ , when the command detection unit 51 ₁ takes in a facsimile signal (command) (FIG. 7 (1)) given from the facsimile device 81 ₁ through the demodulator 35 ₁ and recognizes the reception completion thereof. , Command transmission processing unit 4
1 sends a command reception completion notice to the command reception state determination unit 61 ₁ in _1, and sends it to the digital line through the command relay transmission unit 53 ₁ and the facsimile signal (FIG. 7 (2)). The state determination unit 61 ₁ permits the command transmission unit 62 ₁ to transmit a response signal in response to the command reception completion notification, and when a predetermined time (FIG. 7 (3)) elapses from that timing, the facsimile for the command transmission unit 62 _{1 is performed} . The sending of signals (response signals) is prohibited.

Here, the predetermined time refers to a waiting time (= 3 seconds) from when the facsimile device 81 ₁ sends a facsimile signal to when it retransmits the transmission device 82 ₁ , 82 _2.
Processing delay time, the transmission delay time of the digital line, and the signal length of the response signal are excluded, and the processing delay time and the transmission delay time used for the calculation are for the round-trip transmission path sandwiching the facing facsimile apparatus 81 _2. Is the integrated value of.

The command transmission unit 62 ₁ has a state determination unit 61 1.
_When the response signal is given from the digital line via the command relay receiving unit 55 ₁ in the state where the transmission of the response signal is permitted from ₁ (FIG. 7 (4)), the response signal (added to the beginning immediately) (Including the preamble signal) to the facsimile apparatus 81 ₁ . However, in the state where the transmission is prohibited, the command transmitting unit 62 ₁ retransmits the facsimile signal retransmitted from the facsimile apparatus 81 ₁ (see FIG. 7).
Until the transmission permission is given again in accordance with (5)), the contents of the response signal are held and stand by, and as soon as the transmission permission is given, the response signal is transmitted to the facsimile apparatus 81 ₁ (FIG. 7 (6)). ).

As described above, according to this embodiment, even if there is a processing delay of the transmission device and a transmission delay of the digital line,
Since the transmission timing of the response signal to the facsimile device is set to a timing different from the retransmission of the facsimile signal by the facsimile device, the facsimile signal and the response signal collide on the two-wire line connecting the facsimile device and the transmission device. There is nothing to do.

[0036] In the embodiment corresponding to the invention described in claim 1, when the facsimile signal transmitted from the facsimile apparatus ₈₁₁ is received by the command detector 51 _1, the preamble signal to the facsimile device 81 ₁ While sending the start, the present invention is not limited to such timing, for example, as long as the facsimile apparatus 81 ₁ can afford on the time until the timing axis retransmitting the same facsimile signal, set further delayed timing May be.

Further, the command reception processing section 39 ₁ (39 ₂ )
Regarding the command transmission processing unit 41 ₁ (41 ₂ ),
Dedicated hardware or a part thereof may be realized by controlling software using a microprocessor or the like.

[0038]

As described above, according to the present invention, the transmission timing of the response signal transmitted by the transmission apparatus to the facsimile signal transmitted from the facsimile apparatus is ensured until the facsimile apparatus retransmits the same facsimile signal. Set the timing so that transmission can be completed.

That is, on the two-wire line connecting the facsimile apparatus and the transmission apparatus, collision between the retransmitted facsimile signal and the response signal to the facsimile signal transmitted prior to this is avoided. In a facsimile communication system that transmits an analog facsimile signal via a digital line, retransmission and other communication procedure control corresponding to the above-mentioned collision are not performed, and the efficiency and stability of facsimile communication can be achieved.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the invention according to claim 1.

FIG. 2 is a principle block diagram of the invention described in claim 2.

FIG. 3 is a diagram showing a configuration example of a transmission device to which the present invention is applied.

FIG. 4 is a diagram showing an embodiment corresponding to the invention described in claim 1.

FIG. 5 is a diagram explaining an operation of an embodiment corresponding to the invention described in claim 1.

FIG. 6 is a diagram showing an embodiment corresponding to the invention described in claim 2.

FIG. 7 is a diagram explaining an operation of an embodiment corresponding to the invention described in claim 2;

FIG. 8 is a diagram showing a configuration example of a conventional facsimile signal transmission system.

FIG. 9 is a diagram illustrating a problem of the conventional technique.

[Explanation of symbols]

11, 81 ₁ , 81 ₂ Facsimile device 13, 31 ₁ , 31 ₂ , 82 ₁ , 82 ₂ Transmission device 15 Transmission activation control means 21 Transmission regulation control means 32 ₁ , 32 ₂ Transmission section 33 ₁ , 33 ₂ Reception section 34 ₁ , 34 ₂ A / D converters 35 ₁ , 35 ₂ demodulators 36 ₁ , 36 ₂ , 42 ₁ , 42 ₂ switching control units 37 ₁ , 37 ₂ speech encoders 38 ₁ , 38 ₂ , 44 ₁ , 44 ₂ selectors 39 ₁ , 39 ₂ command reception processing unit 40 ₁ , 40 ₂ voice decoder 41 ₁ , 41 ₂ command transmission processing unit 43 ₁ , 43 ₂ D / A converter 45 ₁ , 45 ₂ modulator 51 ₁ , 51 ₂ command Detection units 52 ₁ , 52 ₂ , 61 ₁ , 61 ₂ Command reception state determination units 53 ₁ , 53 ₂ Command relay transmission units 54 ₁ , 54 ₂ , 62 ₁ , 62 ₂ Command transmission units 55 ₁ , 55 ₂ Command relay reception unit 83 ₁ , 83 ₂ telephones

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Internal reference number for FI Technical indication H04N 1/00 104 B 4226-5C (72) Inventor Sumiko Kido 1-8 Oyama-machi, Kanazawa-shi, Ishikawa Prefecture No.Fujitsu Hokuriku Communication System Co., Ltd.

Claims (2)

[Claims] 1. Transmitting and receiving an analog facsimile signal,
A facsimile device (11) that resends the same facsimile signal if a response signal to the facsimile signal is not received within a predetermined time, and a transmission device (13) that interfaces the facsimile device (11) with a digital line. In a facsimile signal transmission system, a facsimile device (1
1) The facsimile signal transmitted by 1) is monitored, and from the time when the signal is detected, as a starting point, the processing time of the interface, the transmission delay time of the digital line, and the signal length of the response signal are excluded from the predetermined time. A facsimile signal transmission system comprising: a transmission activation control means (15) for activating the transmission processing of the response signal in the transmission device (13). 2. Sending and receiving analog facsimile signals,
A facsimile device (11) that resends the same facsimile signal if a response signal to the facsimile signal is not received within a predetermined time, and a transmission device (13) that interfaces the facsimile device (11) with a digital line. In a facsimile signal transmission system, a facsimile device (1
1) The elapsed time from the time of detecting the facsimile signal transmitted by 1) is monitored, and the elapsed time is the time obtained by removing the processing time of the interface, the transmission delay time of the digital line and the signal length of the response signal from the predetermined time. Facsimile signal transmission system characterized by comprising a transmission regulation control means (21) for regulating the transmission processing of the response signal performed by the transmission device (13).