JPH0969924A - Facsimile communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time of all image data by putting a facsimile communication procedure signal in a frame together with image data and sending them together. SOLUTION: In the ECM communication mode, the image data are divided and transmitted in a plurality of FCD(facsimile encoded data) frames, and the facsimile communication procedure signals are put in the frames together with the image data and transmitted. In this case, a PPS-MPS(multi-page signal) as a post message instruction is added to the image data (facsimiles 1-5) of a 1st page, then the image data (frames 6-8) of a 2nd page and a PPS-EOP (procedure end signal) at the end are added, and those are transmitted in one block. Consequently, the PPS-MPS transmitted between pages and the PPS-EOP sent at the end of all pages can be transmitted as a high transmission speed as well as the image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a facsimile communication method in ECM communication mode.

[0002]

2. Description of the Related Art Recently, as a facsimile machine, a facsimile machine having an ECM communication mode in addition to a normal communication mode for transmitting image data of an original in page units has become widespread. The ECM communication mode is for transmitting and receiving image data in 1 block units composed of, for example, 256 frames. When an error occurs in the image data in 1 block, until 1 block of image data can be transmitted correctly. Image data communication in frame units is repeatedly executed. Therefore, in the case where a facsimile transmission to an area where a communication error is likely to occur, for example, overseas is performed, the facsimile transmission in the ECM communication mode is effective.

In such an ECM communication mode, image data is divided into, for example, 256 bytes each and transmitted / received as one frame, but an error occurs in the data due to line noise or momentary interruption. there is a possibility. In order to detect this error, a CRC check (cyclic redundancy check) is performed on the receiving side to improve data quality. This CRC
If an error frame is detected as a result of the check, the frame number in error is specified, and the transmitter is repeatedly requested to retransmit only the error frame until the error is no longer detected.

FIG. 3 shows an example of a facsimile communication method in the ECM communication mode. In the figure,
(A) to (m) are codes for signals transmitted and received in the facsimile communication procedure. CN from sender
By transmitting G (calling tone), a facsimile communication procedure is started, and a handshake with the receiving side is executed (a) to (f). After that, the image data is converted into multiple FCDs
(Facsimile coded data) is divided into frames and transmitted (g), (j), and it is judged from the response whether or not the transmitted frame is normally transmitted (i), (l).

This response is MCF (message confirmation signal)
If it is, it is determined that the transmission was normal and the next frame is transmitted (j), or DCN (disconnection command signal) is transmitted (m), and this communication procedure can be ended. it can. On the other hand, when the response is PPR (retransmission request), it is determined that the transmission is abnormal, and the frame designated in the PPR is retransmitted.

In the image data transmission shown here, image data for one page is transmitted in block units. In the figure, the first page is composed of 5 frames and the second page is composed of 3 frames. Sending.

[0007]

However, in the above-mentioned conventional facsimile communication method, the facsimile communication procedure signal (handshake, that is, post message command transmission / response reception) between pages (blocks) is frequency modulated (FSK). Communication speed (300 bp)
image data is transmitted at high speed (for example,
Even if transmission is performed at 14.4 bps by quadrature phase amplitude modulation (QAM), it is necessary to reduce the transmission speed after transmitting one page of image data. for that reason,
It takes time to transmit the image data of all pages, and it has been desired to propose a facsimile communication method that shortens the transmission time.

The present invention has been proposed in view of the above points, and when transmitting image data of a plurality of pages in the ECM communication mode, the transmission speed is kept high to shorten the entire transmission time. The purpose of the present invention is to provide a facsimile communication method.

[0009]

A facsimile communication method according to claim 1, which is proposed to achieve the above object, transmits a facsimile communication procedure signal in a frame together with image data in an ECM communication mode. It is characterized by According to this, since the facsimile communication procedure signal, which must be transmitted at a low speed, can be transmitted by the same high-speed QAM method as the image data, the transmission time for all image data can be shortened.

According to a second aspect of the present invention, there is provided the facsimile communication method according to the first aspect, in which a facsimile communication procedure signal embedded in a frame is to be transmitted by interposing it between pages of image data. It is characterized in that it is transmitted as a signal. The facsimile communication procedure signal to be transmitted by interrupting this page is a post message command, and is a PPS-MPS.
(Multi-page signal), PPS-EOM (message end signal), PPS-EOP (procedure end signal), and the like.
As a result, the time required for the handshake between pages can be greatly reduced.

A facsimile communication method according to a third aspect is the communication method according to the second aspect, characterized in that the facsimile communication procedure signal includes mode information of image data of the next page. By this, PP
Since the mode information such as the document size and the sub-scanning line density can be transmitted at the same time as the S-EOM is transmitted, the mode of the image data of the next page can be designated without transmitting / receiving the facsimile communication procedure signal. The image data can be transmitted based on the mode information.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a facsimile communication method according to the present invention. In the figure, (1) to (9) are numbers added to respective signals transmitted and received in the facsimile communication procedure.

CNG (calling tone) from the transmitting side
Upon transmission (1), the facsimile communication procedure is started. If the error correction mode bit included in the DIS (digital identification signal) from the receiving side is "1", ECM
Indicates that communication in the communication mode is possible (3). On the other hand, the transmitting side specifies "1" in the error correction mode bit of DCS (digital command signal) to start transmission in the ECM communication mode (4).

In the ECM communication mode, the image data is divided into a plurality of FCD (facsimile coded data) frames and transmitted, but in the present invention, the facsimile communication procedure signal is incorporated in the frame together with the image data and transmitted. Characterize. It should be noted that the transmission side can be designated to be transmitted in such a data format by a signal such as NSS, and the reception side receives this and identifies the facsimile communication procedure signal from the image data.

In this figure, PPS- which is a post message command is added to the image data (frames 1 to 5) of the first page.
MPS (multi-page signal) is added, followed by image data of the second page (frames 6 to 8) and finally PPS.
-EOP (procedure end signal) is added and these are transmitted as one block (7). As a result, PPS-MPS transmitted between pages and PPS-EOP transmitted at the end of all pages can be transmitted at the same high transmission rate as image data, and P
It becomes unnecessary to receive a response to PS-MPS (see (h), (i), and (k) in FIG. 3). Therefore, the transmission time can be reduced by, for example, about 5 seconds.

After transmitting the PPS-EOP, the transmission speed is set to a low speed and the response is MCF (message confirmation signal).
When (8) is received, DCN (disconnection command signal) is transmitted and communication is ended (9). When a PPR (retransmission request) specifying an error frame is received as a response,
The designated frame (including a facsimile communication procedure signal depending on the frame) is retransmitted, and the retransmission is repeated until there is no error.

Next, the configuration of blocks transmitted by the facsimile communication method according to the present invention will be described with reference to FIG. This figure shows a block configuration example when transmitting image data from the first page to the n-th page. In the ECM communication mode, image data is transmitted in the HDLC frame structure, and one frame is a flag,
It is composed of an address, control, FCS (frame check sequence), flag and arbitrary data. Arbitrary data is composed of a data identification, a frame number, and encoded image data. Depending on the data type, an FCD frame and an RCP that is added to the end of the block and transmitted.
(Return to control) frame is identified. Here, one block has a maximum of 256 frames (frame number 0
Up to 255), a maximum of 25 per frame
Assuming that 6-byte image data can be transmitted, one block enables transmission of 64 Kbyte image data.

The image data of the first page is frame number 0.
Stored in frames 4 to 4, following RTC (control return signal), PPS-EOM (message end signal)
And the mode information of the image data of the next page (second page) is added (see frame number 4). As described above, according to the present invention, conventionally, after transmitting the PPS-EOM, the mode information such as the document size and the sub-scanning line density, which is designated to the receiving side by the facsimile communication procedure signal (DCS or the like), is also included in the frame. It can be included and sent.

Between the second page and the third page, the PPS
-MPS is inserted, and the third page transmits in the same mode as the second page (see frame number 8). The image data of the nth page is transmitted over the first block (frame number 255) and the second block (frame numbers 0 to 2). At this time, the transmission speed between the blocks is switched to a low transmission speed, and the facsimile communication procedure signal (PP
S-NULL, MCF, etc.) is transmitted and received.

From the above, when the transmission speed is changed from high speed to low speed in the transmission of image data, the PPS-EOP is set when the block having the maximum block length is transmitted or the transmission of the image data of all pages is completed. When sent (second
Limited to block frame number 2).

[0021]

As can be understood from the above description, according to the facsimile communication method according to claims 1 to 3 of the present invention, in the conventional ECM communication mode, the facsimile communication procedure signal transmitted at low speed is transmitted. Since the data can be embedded in the frame together with the image data and transmitted, the number of times of changing the transmission speed can be reduced, continuous transmission can be performed at high speed, and the transmission time for all image data can be shortened. In addition, it is possible to save the communication fee.

In particular, according to claim 2, the time required for the handshake between pages can be greatly shortened, so that the transmission time for the image data of all pages is shortened as compared with the conventional ECM communication mode. You can do it. Further, according to the third aspect, since the frame information is transmitted together with the image data together with the mode information on the next page, it becomes unnecessary to transmit / receive the facsimile communication procedure which is conventionally executed to change the mode between pages. Further, the transmission time can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an example of a facsimile communication method according to the present invention.

FIG. 2 is a diagram showing an example of a block configuration transmitted by a facsimile communication method according to the present invention.

FIG. 3 is a diagram illustrating an example of a conventional facsimile communication method.

[Explanation of symbols]

(1) to (9) ... Number added to signals transmitted and received by the facsimile communication method of the present invention

Claims (3)

[Claims] 1. A facsimile communication method characterized in that, in an ECM communication mode in which image data is divided into a plurality of frames and transmitted by facsimile, a facsimile communication procedure signal is incorporated into the frame together with the image data and transmitted. 2. The facsimile communication method according to claim 1, wherein the facsimile communication procedure signal embedded in the frame is interrupted between pages of image data to be transmitted as a facsimile communication procedure signal to be transmitted. Characteristic facsimile communication method. 3. The facsimile communication method according to claim 2, wherein the facsimile communication procedure signal includes mode information of image data of the next page.