JPH1042116A - Facsimile equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide facsimile equipment in which increase in a communication time due to re-transmission due to an error is prevented even when many re- transmission operations take place due to an error of a same page during communication through a line with a deteriorated quality. SOLUTION: On the occurrence of lots of errors, the communication is conducted by changing modulation/demodulation methods and the communication mode. A control section 1 executes a program stored in a ROM 4 to conduct sequence control of the entire facsimile equipment. When an operation section 2 is used to set permission/inhibit of change from an error re-transmission (ECM) mode to the G3 mode and to enter a specified value of number of re- transmission times or the like, the entered information is stored in a RAM 3. A recording section 5 records a facsimile message and a report or the like, and a read section 6 reads an original. A MODEM section 9 extracts image information coded by a coding/decoding section 7 from an image memory 8 to conduct modulation/demodulation of all data required for facsimile communication and to conduct framing/de-framing of the HDLC protocol. A line control section 10 controls call transmission and call reception based on an instruction of the control section 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus, and more particularly, to a facsimile apparatus, in which when a retransmission due to an error of the same page occurs frequently during communication through a poor quality line, a modulation / demodulation method is used.
The present invention relates to a facsimile apparatus capable of changing to another modulation / demodulation method capable of modulation / demodulation in three modes and changing a communication mode from an error retransmission mode (ECM mode) to a G3 mode.

[0002]

2. Description of the Related Art ITU-T recommendation In a facsimile apparatus equipped with a modem of the V.34 modulation / demodulation system, V.34 is used. Since it is necessary to transmit and receive a message in the ECM mode when communicating in the 34 modulation / demodulation method, this type of conventional facsimile apparatus transmits and receives a message in the ECM mode.

[0003]

The conventional ITU-T
Recommendation V. A facsimile apparatus equipped with 34 modems capable of modulation / demodulation transmits and receives messages in the ECM mode. However, when communication is performed in the ECM mode through a line having poor line quality and a lot of noise, error retransmission frequently occurs and a communication time is lengthened, so that there is a problem that a communication cost increases.

[0004] An object of the present invention is to provide a modulation / demodulation system that can be used when the retransmission of the same page frequently occurs during communication through a poor quality line. Preventing increase in communication time due to error retransmission by changing from 34 modulation / demodulation method to another modulation / demodulation method capable of modulation / demodulation in G3 mode and changing communication mode from ECM mode to G3 mode. It is an object of the present invention to provide a facsimile apparatus that can perform the above-described operations.

[0005]

According to the present invention, an ITU
V. of the -T Recommendation. In a facsimile apparatus equipped with a modem of the V.34 modulation / demodulation method, when the number of retransmissions due to an error of the same page exceeds the specified number during communication through a line, the modulation / demodulation method is changed to the above-mentioned V.34. A modification for changing from 34 modulation / demodulation methods to another modulation / demodulation method capable of performing modulation / demodulation in the G3 mode.
Demodulation method changing means and change communication mode from ECM mode to G
A facsimile apparatus comprising: a communication mode changing unit for changing to three modes.

Further, input means for inputting the prescribed number of error retransmissions and permission or prohibition of the change of the communication mode, storage means for storing information input from the input means, All the modulation / demodulation methods necessary for facsimile communication including the 34 modulation / demodulation methods are possible.
A facsimile apparatus comprising a demodulating means and a control means for controlling the change of the communication mode and the execution of the communication operation is obtained.

[0007] Further, the modulation / demodulation means is provided with the V.D. 34
In addition to the modulation / demodulation method, 17, V. 29 and V.I. 27
A facsimile apparatus characterized by being capable of performing modulation / demodulation including any of the ter modulation / demodulation methods.

[0008]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a facsimile apparatus of the present invention, and FIG. 2 is a sequence diagram showing a communication operation in this embodiment.

Referring to FIG. 1, a facsimile apparatus according to the present embodiment has a control unit 1 for controlling a sequence of the entire apparatus.
And an operation unit 2 for inputting destination information, setting of permission / prohibition of change from the ECM mode to the G3 mode, a prescribed value of the number of error retransmissions, and the like, and information input from the operation unit 2. RAM 3, ROM 4 storing a program to be executed by the microprocessor of control unit 1, recording unit 5 for recording facsimile messages and reports, reading unit 6 for reading an original, encoding / decoding of image information Encoding / decoding unit 7 for performing encoding, an image memory 8 for storing encoded image information, and capable of modulating / demodulating all data necessary for facsimile communication and performing framing / deframing of HDLC. And a line controller 10 for controlling outgoing and incoming calls according to instructions from the controller 1.
It is composed of

Next, the operation of this embodiment will be described with reference to FIG.

When the number of retransmissions on the same page, destination information of abbreviated dialing, and one-touch dialing and information of permission / prohibition of mode change from ECM mode to G3 mode specified for each destination are input from the operation unit 2, the control unit 1 Stores these information in the RAM 3.

When the start of transmission is designated by the one-touch dial or the abbreviated dial destination from the operation unit 2, the control unit 1 reads out the corresponding destination information stored in the RAM 3 and sends it to the line control unit 10. The destination information is notified, dial signal transmission is instructed, and connection with the other party facsimile machine is performed.

This V. In the procedure of I.8, ITU-T Recommendation V. When it is recognized that the facsimile communication capability of No. 34 is available, 34, and In the data transfer phase following the exchange of modem parameters of the control channel of ITU-T Recommendation T.34.
A signal exchange between the non-standard capability signal NSF and the non-standard setting command signal NSS shown at 30 is performed.

As a result, V.V. 34 ECM mode to other modulation schemes (V.17, V.29, V.27ter)
Etc.) is performed to determine whether or not there is a mode change capability to the G3 mode.

After that, the control unit 1 reads the image information encoded by the encoding / decoding unit 7 from the image memory 8 and converts the image information into an HDLC frame by the modem unit 9. It transmits on the 34 primary channels.

When the transmission of the page (including the partial page) is completed, the control unit 1 sends the V.V. ITU-T Recommendation T.34 using the control channel of ITU-T. Indicate the transmission of the post message shown at 30.

When the response signal from the receiver to the post message is the partial page request signal PPR, the control unit 1 increments the same page retransmission counter (not shown) in the RAM 3 by one.

When the response signal from the receiver is the message acknowledgment signal MCF, the control unit 1 clears the same page retransmission counter in the RAM 3 to zero.

Here, the control unit 1 compares the number of retransmissions of the same page stored in the RAM 3 in advance with the value of the same page retransmission counter, and if both match, the destination stored in the RAM 3 is G3. If the mode change to the mode is permitted, the facsimile information field FI
Retransmission end signal / message end signal EOR-E with F
It instructs the modem unit 9 to transmit OM + FIF (shown in FIG. 2), and notifies the receiver that the communication mode is changed to the G3 mode of another modulation method.

Hereinafter, V.P. General ITU-T Recommendation T.21 using high-speed channel Ch2. The negotiation is performed again according to the procedure of V.30. 17 (V.29, V.N.
In the G3 mode of the modulation method of 27 ter, etc., control is performed so that transmission is restarted from the retransmitted page stored in the image memory 8.

In the exchange of the non-standard capability signal NSF and the non-standard setting command signal NSS, when it is negotiated that the mode change from the ECM mode to the G3 mode of another modulation method is impossible, and retransmission of the same page occurs frequently. , The control unit 1 terminates the communication once, and 17, V. 29,
V. Control is performed so that transmission is performed in the G3 mode of another modulation method such as 27ter.

[0023]

As described above, the present invention provides an ITU-
T. Recommendation V. In a facsimile apparatus equipped with a modem of the V.34 modulation / demodulation method, the modulation / demodulation method is set to V.34 when the number of retransmissions due to the error of the same page exceeds the specified number during communication through a line. A modulation / demodulation method changing means for changing from the 34 modulation / demodulation method to another modulation / demodulation method capable of changing / demodulating in the G3 mode; and a communication mode changing means for changing the communication mode from the ECM mode to the G3 mode. Input means for inputting a prescribed number of error retransmissions and permission or prohibition of changing the communication mode; storage means for storing information input from the input means; 34, a modulation / demodulation means capable of modulating / demodulating all the modulation / demodulation methods necessary for facsimile communication including the 34 modulation / demodulation methods, and a control means for controlling the judgment of the change of the communication mode and the execution of the communication operation. Thus, furthermore, the modulation / demodulation means may have V.34 modulation / demodulation method. 17, V. 29 and V.I. Since it is possible to perform modulation / demodulation including any of the 27 ter modulation / demodulation methods, operation in the ECM mode is essential. Since the communication of the 34 modulation / demodulation method is changed to the communication of another modulation / demodulation method capable of performing the modulation / demodulation in the G3 mode so that the error retransmission is not performed, the line quality is poor and there is a lot of noise. This has the effect of suppressing an increase in communication cost when communicating.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a facsimile apparatus of the present invention.

FIG. 2 is a sequence diagram illustrating a communication operation according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 2 Operation part 3 RAM 4 ROM 5 Recording part 6 Reading part 7 Encoding / decoding part 8 Image memory 9 Modem part 10 Line control part

Claims (3)

[Claims] 1. The ITU-T Recommendation V.1 In a facsimile apparatus equipped with a modem of the V.34 modulation / demodulation method, when the number of retransmissions due to an error of the same page exceeds the specified number during communication through a line, the modulation / demodulation method is changed to the above-mentioned V.34. 34 changes /
Modulation / demodulation method changing means for changing the demodulation method to another modulation / demodulation method capable of changing / demodulating in the G3 mode, and communication mode changing means for changing the communication mode from the error retransmission mode to the G3 mode. Facsimile machine characterized. 2. An input means for inputting the specified number of error retransmissions and permission or prohibition of change of the communication mode, a storage means for storing information input from the input means, A modulating / demodulating means capable of modulating / demodulating all the modulating / demodulating methods necessary for facsimile communication including the 34 modulating / demodulating methods, and a control means for controlling the judgment of the change of the communication mode and the execution of the communication operation. The facsimile apparatus according to claim 1, further comprising: 3. The modulation / demodulation means according to claim 1, wherein V.34 modulation / demodulation method. 17, V. 29 and V.I. 27ter
3. The facsimile apparatus according to claim 2, wherein the facsimile apparatus is capable of performing modulation / demodulation including any of the modulation / demodulation methods.