JPH01200780A - facsimile machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a transmission control method for a facsimile machine.

[Prior art] In recent years, facsimile machines that have been widely used are CCIT.
Group 3 facsimile machines recommended by T (International Telegraph and Telephone Advisory Committee) are the mainstream.

The transmission control procedure in this Group 3 facsimile machine is to transmit a transmission procedure signal having the format shown in FIG. 3(a).
This is done by using a 21 modem with a transmission speed of 300 bps.

This transmission procedure signal consists of a preamble PB for synchronizing the signal timing of the transmitter/receiver, and binary code information BC that indicates the contents of the transmission procedure signal.

In addition, the preamble PB is as shown in FIG.
It has a format in which an 8-bit flag sequence F consisting of a prescribed bit pattern is continued for one second, and is added to the binary code information BC every time the transmission direction of the transmission procedure signal is switched.

As shown in the same figure (C), the binary code information BC is H
It is configured in a frame format compliant with DLC (High Level Data Link Procedure), and includes a flag sequence F, an address field A consisting of a predetermined bit pattern (global address), and a control field C consisting of a bit pattern specific to the facsimile machine. , a facsimile control field FCF in which 8-bit pattern data of a facsimile transmission procedure signal is arranged, a facsimile information field PIF in which various information added to the facsimile transmission procedure signal is arranged, a frame check sequence FC3 for error detection, and (tail) flag sequence F is sequentially formed.

For example, when a transmitting device transmits a one-page document, image information is transmitted to a receiving device according to the procedure shown in FIG.

That is, first, when the transmitting device calls the receiving device, the receiving device responds with a tone signal CED to notify that the own terminal is a non-voice terminal, and notifies the non-standard functions that the own terminal is equipped with. The terminal sends a response to the transmitting device with a signal NSF to notify the terminal and a signal DIS notifying the standard functions installed in the own terminal, with a preamble PB added to the beginning.

As a result, the transmitting device transmits the signal DC5, which determines the function (standard function) to be used at that time, to the preamble PB.
is added to the signal and sent to the receiving device, and then the signal TCP is sent for modem training.

When the receiving device properly receives the signal TCP, it responds to the transmitting device by adding a signal CFR to that effect and a preamble factor]B.

As a result, the transmitting device transmits the image information PIX formed by encoding and compressing the image signal of the transmitted original to the receiving device, and when the transmission is completed, it sends a preamble signal EOP to notify the end of the transmission procedure. It is sent to the receiving device with the PB added.

When the receiving device receives the image information PIX without error, it responds to the transmitting device by adding a signal MCF to that effect and a preamble PB.

When the transmitting device receives the signal MCF, it transmits a signal DCN warning that the line should be disconnected, with a preamble PB added thereto, to restore the line.

Further, the receiving device that has received the signal DCN restores the line, thereby ending the image information transmission.

In this way, signals NSF, DIS, signal DC3, signal C
A preamble PB is added to the beginning of each of the FR1 signal EOP, signal MCF, and signal DCN, and therefore, 6 seconds of the time for exchanging transmission procedure signals is spent transmitting the preamble PB.

For this reason, conventionally, the time required for the transmission procedure is long, resulting in the disadvantage that the time required for transmitting the image information is long.

[Objective] The present invention was made in order to solve the problems of the prior art, and it is an object of the present invention to provide a transmission control method for a facsimile machine that can shorten the time required to transmit image information.

[Configuration] In order to achieve this object, the present invention shortens the preamble added to the beginning of the transmission procedure signal.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a facsimile machine according to an embodiment of the present invention.

In the figure, a CPU (central processing unit) 1 is for controlling the entire facsimile machine and facsimile transmission control procedures, and its control program is stored in a ROM (read-only memory) 2. A work area and the like are formed in a RAM (Random Access Memory) 3.

The scanner 4 is for reading a transmitted original at a predetermined resolution, and the plotter 5 is for recording and outputting a received image at a predetermined resolution.

The operation display section 6 is for operating the facsimile machine, and the image storage device 7 is for storing encoded and compressed image information.

The encoding/decoding unit 8 encodes and compresses the transmitted image signal, and decodes the received image information into the original image signal. The network control device 10 modulates and demodulates digital data so that it can be used as a line, and the network control device 10 connects the facsimile device to the public telephone line network. The modem 9 has a low-speed (V, 21) modem function for exchanging transmission procedure signals and a high-speed modem function for exchanging image information, and the network control device 10 has an automatic call/receive function. We are prepared.

Also, CPU1. ROM2, RAM3, scanner 4,
The plotter 5, operation display section 6, image storage device 7, encoding/decoding section 8, modem 9, and network control device 10 exchange data with each other via a system bus 11.

Now, when using the domestic public telephone line network as a transmission route, the line condition is relatively good, so the length of the preamble PB added to the transmission procedure signal should be about 200 milliseconds, as shown in Figure 3. For example, it is fully possible to synchronize the low speed modem function of the modem 9 between the transmitting and receiving devices.

Therefore, in this embodiment, a non-standard function is provided to shorten the preamble PB from 1 second to 200 milliseconds, thereby shortening the time required for exchanging transmission procedure signals. In addition, in the following explanation, 2
A transmission mode using a preamble PB of 00 milliseconds is called a shortened protocol mode.

A description will be given of a case where the facsimile apparatus shown in FIG. 1 with the above configuration is used as both a transmitting and receiving apparatus and transmits one original document.

That is, first, when the transmitting device calls the receiving device, the receiving device responds with a tone signal CED to notify that the own terminal is a non-voice terminal, and notifies the non-standard functions that the own terminal is equipped with. The terminal sends a response to the transmitting device with a signal NSF to notify the terminal and a signal DIS notifying the standard functions installed in the own terminal, with a one-second long preamble LPB added to the beginning.

At this time, the signal NSF includes information indicating that the own terminal is equipped with the shortened protocol mode.

As a result, the transmitting device knows that the receiving device is equipped with shortened protocol 1 to protocol mode, and sends a signal NSS having contents that specify the shortened protocol mode to be used at that time and the transmission function to be used. A short preamble SPB of 200 milliseconds is added and sent to the receiving device, followed by a signal TCP for modem training.

When the receiving device receives the signal NSS, it knows to use the short protocol mode, and when it properly receives the signal TCP, it responds to the transmitting device by adding a greeting signal CFR and a short preamble PB. do.

As a result, the transmitting device transmits the image information PIX formed by encoding and compressing the image signal of the transmitted document to the receiving device, and when the transmission is completed, it briefly sends a signal EOP to notify the end of the transmission procedure. It is sent to the receiving device with the preamble PB added.

When the receiving device receives the image information PIX without error, it responds to the transmitting device by adding a signal MCF to that effect and a short preamble PB.

When the transmitting device receives the signal MCF, it transmits a signal DCN warning that the line should be disconnected, with a short preamble PB added thereto, to the receiving device, thereby restoring the line. Further, the receiving device that has received the signal DCN restores the line, thereby ending the image information transmission.

In this case, a 1-second long preamble LPB is added to the signals NSF and DIS, and the signal D
C5, signal CFR1 signal EOP, signal MCF and signal DCN each have a short preamble SPB of 200 milliseconds added, so that the time spent transmitting the preamble PB in the time for transmitting the transmission procedure signal is , the conventional 6 seconds will be reduced to 2 seconds, a reduction of 4 seconds.

Therefore, the time required to transmit image information is significantly shortened to 4 seconds.

Although the case where the image information of one original to be transmitted is properly transmitted has been described here, the effects of this embodiment can be similarly applied even when transmitting two or more originals. Hail!

By the way, as mentioned above, the shortened protocol mode can be used effectively especially when using the domestic public telephone network, so the shortened protocol mode can only be used when a domestic phone number is set and input as the destination. It is recommended to enable it.

That is, when an overseas telephone number is set and input as a transmission destination, the signal NSF is configured not to include information about the shortening program 1 - Cormeaux 1.

Further, the length of the short preamble in the shortened protocol mode is not limited to 200 milliseconds as in the above-described embodiment, and can also be set to an appropriate value depending on the line status.

The present invention also provides a facsimile device, etc. that transmits image information without error using a non-standard automatic retransmission method (ARQ).
The present invention can be similarly applied to group 3 facsimile machines other than the apparatuses of the above-described embodiments.

[Effect] As explained above, according to the present invention, the time required for the transmission procedure is shortened by shortening the preamble added to the beginning of the transmission procedure signal, so the time required for transmitting image information is shortened. Get the effect of being able to do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a facsimile device according to an embodiment of the present invention, FIG. 2 is a time chart showing image information transmission using the facsimile device of FIG. 1, and FIG. 3(a) is a transmission diagram. Schematic diagram showing the format of the procedure signal, figure (b)
4 is a schematic diagram showing the contents of a preamble, FIG. 4(c) is a schematic diagram illustrating the contents of binary code information, and FIG. 4 is a time chart showing how image information is transmitted in a conventional apparatus. 1...cpu (central processing unit), 2...RO (
Read-only memory), 3...RAM (random
access memory). Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A transmission control method for a facsimile machine using a transmission procedure of a group 3 facsimile machine, characterized in that the length of a preamble added when transmitting a procedure signal is shortened.