JPH05300353A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To obtain the facsimile equipment in which the transmission time is reduced by selecting the communication in the G3 mode from the ECM mode based on the detection at a receiver side when error re-transmission of picture information takes place during the ECM mode communication. CONSTITUTION:A communication control section 2 has a changeover section 2a selecting the communication in the ECM mode or the communication in the G3 mode in addition to transmission reception control. A memory section 3 stores program for the communication in the ECM mode or the communication in the G3 mode in addition to storage of usual picture data or the like. Furthermore, a CPU 4 controls the changeover section 2a or the like. A code conversion section 5, a recording section 6 and a read section 7 implement the operation of usual facsimile communication. Through the constitution above, when a line error or the like takes place during the communication in the ECM mode, it is detected by a receiver side and the changeover section is operated based on the detection and the communication in the G3 mode is selected, then the transmission time is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to line error retransmission (EC
The present invention relates to a facsimile machine using the M) mode and the group 3 (G3) mode (CCITT recommendation).

[0002]

2. Description of the Related Art A conventional facsimile apparatus cannot automatically switch from the ECM mode to the G3 mode until the end of the communication in the ECM mode when performing the communication in the ECM mode.

[0003]

The above-mentioned conventional facsimile apparatus uses the G3 protocol in order to make a request to retransmit the data to the transmitting side when error retransmission of image data due to a line failure or the like occurs frequently during communication in the ECM mode. There is a problem that the transmission time is added more than that in the mode communication.

The present invention has been made in view of the above problems, and it is possible to shorten the transmission time by automatically switching to the G3 mode for the longer transmission time due to the repeated error resending in the ECM mode communication. The purpose is to provide a facsimile machine.

[0005]

In order to achieve the above-mentioned object, a facsimile apparatus of the present invention is a facsimile apparatus provided with a transmitting / receiving section in ECM mode and group 3 mode, in which error transmission of image information is retransmitted during communication in the ECM mode. When the above occurs, the ECM mode is switched to the group 3 mode communication based on the detection on the receiving side.

[0006]

In the present invention constructed as described above, the EC
When a line error or the like occurs during the M mode communication mode, the receiving side detects this and the switching unit operates based on this detection to switch to G3 mode communication.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of the facsimile apparatus of this embodiment. This facsimile apparatus includes a network control unit 1, a communication control unit 2, a memory unit 3, a CPU 4, a code conversion unit 5, a recording unit 6, and a reading unit 7 for communicatively connecting a telephone line and the inside of the facsimile.

The communication control section 2 has a switching section 2a for switching between ECM mode communication and G3 mode communication as well as transmission / reception control. The memory unit 3 also stores programs for performing ECM mode communication and G3 mode communication as well as storing normal image data and the like. Further, the CPU 4 controls the switching unit 2a and the like. The code conversion unit 5, recording unit 6, and reading unit 7 perform normal facsimile communication operations.

Next, the operation of this facsimile apparatus will be described. First, the G3 mode transition procedure at the time of error reception of the training signal TCF will be described with reference to the sequence diagram of FIG. In phase A, the transmitting side makes a call through the telephone line using the document set and dial, and the transmission operation is started. The receiving side detects the ringer signal sent from the line, the receiving operation is started, and the called station identification symbol CED is sent (step 11).

After the reception operation is started, the phase B is shifted to C
In response to a command from the PU 4, the communication control unit 2 generates a non-standard device NSF, a called station identification signal CSI, and a digital identification signal DIS, which signals are sent to the telephone line through the network control unit 1 (step 12). At that time, among the contents of the function information of the NSF signal, it is declared that there is communication in the ECM mode.

The transmitting side receives the initial identification signal sent from the receiving side and transmits the transmitting station identification signal TS which is a command signal.
An I, non-standard device setting signal NSS is generated in the communication control unit 2 and sent from the network control unit 1 to the receiving side via the line. At this time, the transmitting side receives the function information of the NSF signal sent from the receiving side, starts communication in the ECM mode,
The modem training signal TCF is sent to the receiving side via the line similarly to the command signal (step 13). On the receiving side, the line state is judged from the TCF data, and if it is normally received, a reception preparation confirmation signal CFR is sent to the transmitting side, and thereafter communication is continued in the ECM mode.

However, in step 13 of FIG. 2, when the line state becomes defective and an error is received, the training failure signal FTT is sent to the transmitting side, and then the fallback procedure is started (step 14). At that time, FT
On the transmission side that receives T, the switching unit 2a shifts from the ECM mode to the G3 mode in response to a command from the CPU 4.

Specifically, when the fallback procedure is started after receiving the FTT, the TSI and NSS are returned, but the ECM mode prohibition information is added to the function information of the NSS and sent to the receiving side ( Step 15). The receiver is
After receiving the NSS, the switching unit 2a is instructed by the CPU 4
Is operated to automatically switch from the ECM mode to the G3 mode, and thereafter G3 communication is performed. Again, TC from the sender
F is sent (step 16), CFR is sent from the receiving side (step 17), and the sending side sends image information PIX and page end signal RTC (step 18). After that, the process shifts to the phases D and E, and the facsimile communication is completed by transmitting and receiving the procedure end signal EOP, the message confirmation signal MCF, and the line disconnection signal DCM (steps 19 to 19).
Step 21).

Next, as shown in FIG. 3, the shift to the G3 mode due to an image information error will be described. First, two originals are set, and the TCF is normally received on the receiving side, the CFR is sent, and the process shifts to phase C.
Communicate in CM mode (Step 31 to Step 3)
4). Then, if a line failure occurs during transmission of the image information PIX from the transmission side after the shift to phase C, the ECM mode is automatically switched to the G3 mode from the next page.

Specifically, a line abnormality occurs during transmission of PIX from the transmitting side, and the receiving side monitors the error state of data (steps 35 and 36). RT from sender
After C and MPS, the receiving side receives the retraining negative signal RTN.
When returning, the ECM mode prohibition information of the function information is added to the RTN, and an instruction to switch the subsequent pages to the G3 mode is issued (step 37). After receiving the RTN, the transmission side switches the subsequent pages to the G3 mode for communication (steps 38 to 44).

[0016]

As described above, according to the present invention, the ECM mode is automatically switched to the G3 mode in accordance with the line state, and therefore, the transmission length due to the repeated error resending by the ECM mode communication is increased. The time can be automatically switched to the G3 mode to shorten the transmission time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a facsimile apparatus according to this embodiment.

FIG. 2 is a sequence diagram of G3 mode transition in the case of TCF signal error of the above.

FIG. 3 is a sequence diagram of G3 mode transition when there is a PIX error in the above.

[Explanation of symbols]

 1 network control unit 2 communication control unit 2a switching unit 4 CPU

Claims (1)

[Claims] 1. A facsimile apparatus having an ECM mode and a group 3 mode transmitter / receiver, and when an error retransmission of image information occurs during communication in the ECM mode, the ECM mode is set to the group based on detection by a receiving side. A facsimile apparatus comprising a switching unit for switching to three-mode communication.