JP6638483B2 - Facsimile machine - Google Patents

Description

  The present invention relates to a facsimile apparatus for transmitting a training result to a partner machine when a silent state continues for a predetermined signal disconnection check time after completion of receiving a training signal.

  As the communication environment used for facsimile communication, the environment (digital line) in which a network is interposed on an intermediate route, such as IP-PBX (Internet Protocol Private Branch Exchange), various Network-Gateway devices, and TA (Terminal Adapter), is increasing. I have. In such a communication environment, an echo canceling process is performed in a TA / PBX / Gateway or the like interposed in the middle of the network, but the processing causes a signal delay. On the other hand, processing such as echo cancellation is not performed on the analog line.

  The facsimile apparatus implements measures to prevent echo, instantaneous interruption, and signal batting on the apparatus side in order to support an analog line. Specifically, after receiving the training signal, wait for the duration of the silence state to reach the signal disconnection check time in order to confirm that the training signal from the transmitter has been completely terminated before checking the training result. In the control for sending to the device, the signal disconnection check time is set to a long time such as, for example, 600 ms. According to the standard, the signal disconnection check time may be set between 75 ms and 1.5 s.

  By the way, the international standard T.T. of ITU-T (International Telecommunication Union Telecommunication standardization sector), which is a facsimile communication standard. 30 defines a signal retransmission interval (3 seconds). For example, the transmitter transmits a training signal following the TSI / DCS signal (capability determination information), and then receives a CFR signal (ready for reception) as a training result from the partner before the retransmission interval elapses. Then, the process proceeds to the phase C, and the transmission of the image data is started. However, if the training result is not received from the partner device even after approximately three seconds have passed from the end of sending the training signal, the transmitter starts the retransmission process and sends the TSI / DCS signal and the training signal again. Works.

JP 2006-270377 A

  When a facsimile apparatus that sets a long time (for example, 600 ms) for a signal interruption check time as a preventive measure against echo, instantaneous interruption, signal batting, and the like in an analog line, performs facsimile communication using a digital line. Since the signal delay on the communication line is added, before the training result (CFR signal or FTT signal) transmitted by the receiver reaches the transmitter, the transmitter starts retransmission processing, and finally a communication error occurs. May occur.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a facsimile apparatus capable of coping with both a digital line and an analog line having different characteristics such as a signal delay and an echo cancellation function. I have.

  The gist of the present invention to achieve this object lies in the inventions in the following items.

[1] A facsimile apparatus for transmitting a training result to a partner machine when a silent state continues for a predetermined signal disconnection check time after completion of reception of a training signal,
Have a changing unit that changes a length of the signal interruption check time in accordance with the communication status with the other aircraft,
The status of communication with the partner device is determined by transmitting a capability information signal of the own device and then including a capability determination information signal notified from the partner device. 21 is the length of response time until the beginning of the modulated signal is received,
The change unit, when the response time is equal to or greater than a predetermined threshold, compared with the case where the response time is less than the threshold, shortens the signal disconnection check time,
A facsimile machine characterized by the above.

  In the above invention, the signal disconnection check time for judging the end of the training signal is changed according to the communication state (signal delay time generated in the communication line, signal exchange state in which a difference occurs due to the influence of delay, and the like). .

  In the above invention, the signal disconnection check time set when the response time is equal to or greater than the threshold is set shorter than the signal disconnection check time set when the response time is less than the threshold. In other words, if the response time is equal to or greater than the threshold value, it is determined that the digital line is determined, and if the response time is less than the threshold value, it is determined that the analog line is determined.

[ 2 ] A facsimile apparatus for transmitting a training result to a partner machine when a silent state continues for a predetermined signal disconnection check time after completion of reception of a training signal,
A change unit that changes the length of the signal disconnection check time according to the communication status with the partner device,
When the CFR signal is sent to the partner machine as a training result with the signal disconnection check time set to the first time, the communication status with the partner machine is set to V. 21 whether or not a modulated signal is sent,
In response to a C.V. 21 When the modulated signal is transmitted, before the line is disconnected, the change unit changes the signal disconnection check time to the second time shorter than the first time and receives the next training signal. off Akushimiri equipment it said.

  In the above invention, the V.V. When the communication state is such that the 21st modulated signal is sent, it is determined that the partner machine has missed the training result, and the signal disconnection check time is shortened to perform the next training.

  ADVANTAGE OF THE INVENTION According to the facsimile apparatus which concerns on this invention, the normal communication can be ensured corresponding to both the digital line and the analog line which differ in characteristics, such as a signal delay and an echo cancellation function.

1 is a block diagram illustrating a schematic configuration of a facsimile apparatus according to an embodiment of the present invention. FIG. 9 is a sequence diagram showing a normal communication procedure (phase B) in facsimile communication. FIG. 11 is a sequence diagram showing a communication procedure (phase B) in facsimile communication, in which a transmitter fails to receive a training result when a delay generated in a communication line is large. FIG. 4 is a diagram illustrating timings at which the facsimile apparatus according to the embodiment of the present invention measures a signal delay time of a communication line. FIG. 9 is a sequence diagram illustrating a case where a signal interruption check time is set to t1 and t2 according to a signal delay time. FIG. 4 is a diagram illustrating a state in which the failure in FIG. 3 is avoided by changing the signal disconnection check time to be short (t1; 200 ms) when the signal delay time is equal to or longer than a threshold T. 9 is a flowchart illustrating a process in which the facsimile apparatus according to the present embodiment that operates as a receiver switches signal disconnection check times (first method). If the transmitter fails to receive the training result from the receiver before the elapse of the retransmission interval, it returns to V.25 again. FIG. 11 is a diagram illustrating a state in which capability determination information is transmitted by a 21 modulation signal. 9 is a flowchart illustrating a process in which the facsimile apparatus according to the present embodiment that operates as a receiver switches the signal disconnection check time (second method).

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

  FIG. 1 is a block diagram showing a schematic configuration of a facsimile apparatus 10 according to an embodiment of the present invention. The facsimile machine 10 is connected to another facsimile machine 10 through a communication line constituted by a digital line or an analog line. The facsimile machine 10 includes a CPU (Central Processing Unit) 11 that controls the operation of the facsimile machine 10 via a bus 12, a ROM (Read Only Memory) 13, a RAM (Random Access Memory) 14, and a hard disk drive 15. , A nonvolatile memory 16, an image processing unit 17, a scanner unit 21, a printer unit 22, a display unit 23, an operation unit 24, a network I / F unit 25, and a modem 26 connected to each other. .

  The ROM 13 is a read-only memory in which various programs and fixed data are stored. Each function as the facsimile machine 10 is realized by the CPU 11 executing the processing according to the program stored in the ROM 13. The RAM 14 is used as a work memory for temporarily storing various data when the CPU 11 executes a program, an image memory for storing image data, a buffer memory for communication, and the like.

  The hard disk device 15 is a large-capacity non-volatile storage device, and is used for temporarily storing or storing a job reserved for transmission, its image data, and image data received from another facsimile device 10.

  The nonvolatile memory 16 is a memory that retains the stored contents even when the power is turned off, and registers user information, various setting information, and the like.

  The image processing unit 17 performs processing such as image data reduction, resolution conversion, encoding, and decoding.

  The scanner unit 21 has a function of optically reading a document and acquiring image data. The scanner unit 21 includes, for example, a light source for irradiating the original with light, a line image sensor that receives the reflected light and reads the original by one line in the width direction, and sequentially moves a reading position in line units in the original length direction. Moving means, an optical path including a lens or a mirror for guiding reflected light from the original to the line image sensor to form an image, a conversion unit for converting an analog image signal output from the line image sensor into digital image data, and the like. It is configured with.

  The printer unit 22 has a function of printing an image corresponding to the image data on recording paper. Here, a recording paper transport device, a photosensitive drum, a charging device, a laser unit, a developing device, a transfer separation device, a cleaning device, and a fixing device are provided, and image formation is performed by an electrophotographic process. It is configured as a so-called laser printer. Other types of printers may be used.

  The display unit 23 is configured by a liquid crystal display or the like, and displays various screens such as an operation screen and a setting screen. The operation unit 24 includes various buttons such as a start key, a stop key, and a numeric keypad, and a touch panel provided on the surface of the liquid crystal display and detecting a pressed coordinate position. Accept various operations to be performed.

  The network I / F unit 25 has a function of communicating with an external terminal through a network such as a LAN (Local Area Network) or the Internet. The modem 26 has a function of converting a digital signal into an analog modulated signal and vice versa.

  The CPU 11 performs the functions of the communication status determination unit 31 and the change unit 32 by executing the program. The communication status determining unit 31 determines the communication status with the partner device, and the changing unit 32 changes the length of the signal disconnection check time for the training signal according to the result of the communication status determination by the communication status determining unit 31. .

  A normal communication procedure in facsimile communication will be described with reference to FIG. Here, phase B after communication has been established will be described. The receiver sends receiving capability information (CSI (Called Subscriber Identification) / DIS) indicating its own capabilities (resolution, document size, maximum communication speed, etc.) to the transmitter.

  Upon receiving this, the transmitter determines the communication mode, such as resolution, from the transmission conditions (communication speed, resolution, etc.) set for itself and the capabilities of the receiver recognized based on the reception capability information. The capability determination information (TSI (Transmitting Subscriber Identification) / DCS (Digital Command Signal)) indicating the determined communication mode is transmitted to the receiver. Thereafter, the transmitter further transmits a training signal (TCF) for testing the state of the communication line to the receiver.

  Note that the signal transmitted from the receiver to the transmitter and the signal transmitted from the transmitter to the receiver each have a delay while passing through a communication line on the way and reach the partner device.

  The reception of the training signal is completed when the receiver can confirm the state of the communication line by receiving the training signal for a predetermined time. Thereafter, the end of the training signal is monitored, and when the silent state continues for a predetermined signal disconnection check time, the end of the training signal is recognized. The signal disconnection check time is a time for preventing the instantaneous interruption from being mistaken for the end of the training signal, and is set to a time of, for example, 600 ms in consideration of the influence of an echo generated in an analog line. The T.30 standard states that the signal disconnection check time should be between 75 ms and 1.5 seconds.

  When the receiver recognizes the end of the training signal due to the continuation of the silent state for the signal disconnection check time or longer, it sends the training result to the transmitter. For example, when the training signal is normally received and reception preparation is completed, a CFR (Confirmation To Receive) signal is transmitted as a training result, and when the training fails, an FTT signal is transmitted.

  If the transmitter receives the CFR signal as a training result from the receiver before the specified retransmission interval (3 seconds) elapses after the transmission of the training signal, the transmitter terminates phase B and shifts to phase C. Sends image data.

  FIG. 3 illustrates a case where the training result cannot be received from the receiver before the retransmission interval has elapsed. FIG. 3 shows a larger delay in the communication line than FIG. Therefore, the training result transmitted from the receiver to the transmitter arrives at the transmitter after a retransmission interval of 3 seconds has elapsed since the transmitter finished transmitting the training signal. Since the transmitter could not receive the training result from the receiver before the retransmission interval has elapsed, the transmitter retransmits the capability determination information and the training signal. If the training result cannot be received normally after a predetermined time has elapsed from the start of communication, a communication error occurs and the line is disconnected.

  The present invention is intended to prevent a failure in which a transmitter side misses a training result sent from a receiver due to a delay occurring in a communication line as shown in FIG. In the facsimile apparatus 10 according to the embodiment of the present invention, the length of the signal disconnection check time is changed according to the communication state with the partner machine, particularly, the state of delay occurring in the communication line. There are two methods of determining the communication status: (1) a first method of measuring and determining a signal delay time, and (2) a second method of observing a signal sent from a transmitter side with respect to a training result to determine. There are methods, which will be described respectively.

<First method>
As shown in FIG. 4, after transmitting the receiving capability information (DIS (Digital Identification Signal) signal), the receiver receives the V.V. signal including the capability determination information (DSC) transmitted from the transmitter. The length of a silent section until reception of the 21st modulated signal is started is measured as a signal delay time generated in this communication line.

  If the signal delay time is equal to or longer than a predetermined time (threshold T, for example, 2 seconds), it is determined that the communication environment (digital line) is interposed by the network device, and the signal disconnection after the completion of the training signal reception. The check time is set to a time shorter than the signal disconnection check time set when the signal delay time is less than the threshold value T. Here, the signal interruption check time t1 set when the signal delay time is less than the threshold T is 200 ms, and the signal interruption check time t2 set when the signal delay time is equal to or greater than the threshold T is 600 ms.

  As shown in FIG. 5A, when the measured signal delay time is equal to or longer than the threshold value T (2 seconds), the receiver sets the signal disconnection check time to t1 (200 ms), and after the reception of the training signal, When the silent state continues for t1 (200 ms), it is determined that the training signal has ended, and the training result is transmitted.

  On the other hand, as shown in FIG. 5B, when the measured signal delay time is less than the threshold value T (2 seconds), the receiver sets the signal disconnection check time to t2 (600 ms) and receives the training signal. After the completion, when the silent state continues for t2 (600 ms), it is determined that the training signal has ended, and the training result is transmitted.

  FIG. 6 shows a state in which the failure shown in FIG. 3 is avoided by changing the signal disconnection check time to be short (t1; 200 ms) when the signal delay time is equal to or longer than the threshold value T. By shortening the signal disconnection check time, the receiver sends the training result early, so that even if the delay in the communication line is large, the training result is transmitted before the retransmission interval (3 seconds) elapses. To reach the aircraft. In the example of FIG. 6, as a result of receiving the training result (CFR) by the transmitter, the transmitter has normally shifted to the phase C.

  In the case of a digital line, various network devices on the way perform processing such as temporarily storing data in a buffer and then transmitting the data in order to take measures against echo, so that a corresponding delay occurs. However, in the digital line, since the countermeasures against the echo are performed by the network device, the countermeasures against the echo in the facsimile apparatus 10 become unnecessary, and the signal disconnection check time can be shortened accordingly.

  On the other hand, in the case of an analog line, the delay is slight and causes no problem. However, it is necessary to take measures against the echo on the facsimile apparatus 10 side.

  Therefore, when the facsimile apparatus 10 operates as a receiver, the facsimile apparatus 10 transmits the reception capability information and then transmits the V.F. 21 The silence time (signal delay time) until the reception of the modulated signal is measured, and if this is greater than or equal to the threshold value, it is determined that the communication line used in the current communication is a digital line, and the signal disconnection check time Is set to t1 (200 ms), and when the measured signal delay time is less than the threshold value, it is determined that the communication line used in the current communication is an analog line, and the signal disconnection check time is set to t2 (600 ms). I do.

  FIG. 7 is a flowchart showing a process in which the facsimile machine 10 operating as a receiver switches the signal disconnection check time. When the reception capability information (DIS signal) is transmitted (step S101), It is monitored whether or not the 21st modulation signal (preamble) is detected (step S102). If not detected (step S102; No), the silent measurement time is counted up (step S103).

  V. When the 21 modulation signal (preamble) is detected (Step S102; Yes), the counting up of the silence measurement time is stopped, and it is determined whether or not the silence measurement time (signal delay time) at that time is equal to or greater than the threshold T (Step S102). Step S104). If the silence measurement time is equal to or longer than the threshold value T (Step S104; Yes), the signal disconnection check time is set to t1 (200 ms) (Step S105), and the process proceeds to Step 107. If the silence measurement time is less than the threshold value T (Step S104; No), the signal disconnection check time is set to t2 (600 ms) (Step S106), and the process proceeds to Step 107.

  In step 107, the process waits for the completion of the reception of the training signal (step S107; No). When the reception of the training signal is completed (step S107; Yes), it is determined whether or not the signal disconnection check time (t1 or t2) has elapsed in a silent state. Is determined (step S108). When the signal disconnection check time elapses in the silence state (step S108; Yes), the training result is sent out (step S109), and this processing ends.

<Second method>
As shown in FIG. 8, if the training result cannot be received from the receiver before the retransmission interval (3 seconds) elapses, the transmitter returns to V.11 again. The capability determination information is transmitted by the 21 modulation signal. On the other hand, if the transmitter successfully receives the training result from the receiver before the elapse of the retransmission interval, the transmitter shifts to phase C, and The image data is transmitted by a high-speed signal such as a 17-modulation signal.

  Then, after transmitting the training result, the receiver waits for reception of image data from the transmitter, and 21 to monitor whether a modulated signal arrives. When the preamble of the 21 modulation signal is detected, it is determined that the transmitter could not receive the training result transmitted by the receiver before the elapse of the retransmission interval (3 seconds).

  Factors that cannot receive the training results include packet loss in addition to delays that occur in the communication line.If delays are the cause, reduce the signal disconnection check time so that the transmitter can retransmit at the next training. It is considered that the training result is received before the interval has elapsed.

  Therefore, the receiver initially sets the signal disconnection check time to t2 (600 ms), and after transmitting the training result, the transmitter sets the V.V. It monitors whether a preamble of the 21st modulated signal arrives. And V. When the preamble of the 21 modulation signal is detected, the signal disconnection check time is changed to t1 (200 ms), the end of the next training signal is determined using the signal disconnection check time t1, and the training result is transmitted.

  FIG. 9 is a flowchart illustrating a process when the facsimile apparatus 10 that performs the second method operates as a receiver. The operation relating to the procedure before the training is not shown. The initial value of the signal disconnection check time is set to t2 (600 ms) (step S201). Then, the reception of the training signal is started, and when the reception of the training signal is completed (Step S202; Yes), it is determined whether or not the signal disconnection check time t2 (600 ms) has elapsed in a silent state (Step S203). When the signal interruption check time t2 elapses in the silence state (Step S203; Yes), the training result is transmitted (Step S204). Thereafter, when a high-speed signal arrives from the transmitter side (step S205; No, S206; Yes), the process proceeds to phase C and receives image data (step S207).

  After transmitting the training result, the V.V. If the preamble of the 21st modulation signal is detected (step S205; Yes), the line is disconnected if the capacity exchange is not established within 35 seconds after the communication starts. It is determined whether it is the right time (step S208). If the line disconnection timing has arrived (step S208; Yes), the line is disconnected as a communication error (step S209), and this processing ends.

  If it is not the timing of the line disconnection (Step S208; No), is the next training to be performed the last one in light of the provision that the line is disconnected if the capacity exchange is not established within 35 seconds after the communication starts? It is determined whether or not the training to be performed next is not the last training (step S210; No), and the process returns to step 202 to continue. In this case, the next training is performed with the signal disconnection check time kept at t2.

  If the training to be performed next is the last training before the line disconnection (step S210; Yes), the signal disconnection check time is changed to t1 (200 ms) (step S211), and the process returns to step 202 to continue the process. In this case, the next training is performed at the signal disconnection check time t1 (200 ms).

  If the communication line is a digital line and the delay is large, the signal disconnection check time is changed to t1, so that a high-speed signal is detected for the training result in the final training (step S206; Yes). The communication is continued without causing a communication error.

  The initial value of the signal disconnection check time may be set to t1, and if a communication failure such as retransmission occurs in this state, the signal disconnection check time may be changed to t2. For example, when the initial value is the signal disconnection check time t1 (200 ms), when the other party takes a long time to set up the modem in a situation where the delay on the communication line is small, the other party prepares to receive the training result. Before the training is completed, a situation may occur in which the training result reaches the partner machine and the training result cannot be received. In this case, by changing the signal disconnection check time to t2 (600 ms), normal communication becomes possible.

  When the signal disconnection check time is set to t2 and the result of step S205 is No, it is determined that the communication line is an analog line with a small delay, and the signal disconnection check time is set to t2. If the determination in step S205 is Yes, the communication line is determined to be a digital line with a large delay.

  The change of the signal disconnection check time is not limited to the case where the next training is the last round before the line disconnection. For example, the signal disconnection check time may be changed immediately when the result of step S205 is Yes.

  As described above, according to the present invention, the signal disconnection check time is changed according to the communication state (signal delay time or a signal that is delayed from the transmitter with respect to the training result), so that it is possible to appropriately adjust the delay state occurring in the communication line. And normal communication can be secured.

  As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to those shown in the embodiments, but may be changed or added without departing from the gist of the present invention. Are also included in the present invention.

  The signal disconnection check times t1 (200 ms) and t2 (600 ms) shown in the embodiment are merely examples, and if t1 <t2 and the range is 75 ms to 1.5 S, t1 and t2 are appropriate. It should be a value.

10 facsimile apparatus 11 CPU
12 ... bus 13 ... ROM
14 ... RAM
DESCRIPTION OF SYMBOLS 15 ... Hard disk drive 16 ... Non-volatile memory 17 ... Image processing part 21 ... Scanner part 22 ... Printer part 23 ... Display part 24 ... Operation part 25 ... Network I / F part 26 ... Modem 31 ... Communication status judgment part 32 ... Change part

Claims (2)

A facsimile apparatus for transmitting a training result to a partner machine when a silent state continues for a predetermined signal disconnection check time after completion of receiving a training signal,
A change unit that changes the length of the signal disconnection check time according to the communication status with the partner device,
The status of communication with the partner device is determined by transmitting a capability information signal of the own device and then including a capability determination information signal notified from the partner device. 21 is the length of response time until the beginning of the modulated signal is received,
The change unit, when the response time is equal to or greater than a predetermined threshold, compared with the case where the response time is less than the threshold, shortens the signal disconnection check time,
Off Akushimiri device you wherein a. A facsimile apparatus for transmitting a training result to a partner machine when a silent state continues for a predetermined signal disconnection check time after completion of receiving a training signal,
A change unit that changes the length of the signal disconnection check time according to the communication status with the partner device,
When the CFR signal is sent to the partner machine as a training result with the signal disconnection check time set to the first time, the communication status with the partner machine is set to V. 21 whether or not a modulated signal is sent,
In response to a C.V. 21 When the modulated signal is transmitted, before the line is disconnected, the change unit changes the signal disconnection check time to the second time shorter than the first time and receives the next training signal. off Akushimiri equipment it said.