JPS5994968A - Method for facsimile communication - Google Patents

Abstract

PURPOSE:To save the file after start of transmission and to reduce the communication time by starting coding prior to the start of transmission and storing a coded data into a buffer memory. CONSTITUTION:In starting facsimile communication at a time t0, the message pre-procedure is attained between transmission and receiving facsimile devices. The coding of a picture signal is started at a time t1 when the message preprocedure is attained (between t0 and t2), and the coded data 32 is charged to a buffer memory 11. When the pre-processing is finished, the data transmission is started. Since the data 32 is charged in the memory 11 before the transmission start time t2 in this way, even if the amount of the coded data is less just after the start of transmission, the transmission of the file is decreased remarkably. Thus, the communication time is reduced by a time satisfying the formula t<= (t2-t1) in comparison with the case that no coding is attained before the start of transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a back memory for storing encoded image signal data. Regarding a communication method of a facsimile device having a conventional facsimile f
In the second book,! In order to secure time for recording line image signals, the minimum transmission time for each line is defined as TMIN (mU seconds). Such a high speed facsimile 1f
et1t, as shown in FIG. 1, reads the specific gravity signal at reading 51flS2 of the sending facsimile device fl and encodes the specific gravity signal in 1 rai/unit by encoder 3 and adds a -72in end signal (EOL signal). , the image information is modulated by the modulator 4 and then sent to the transmission path 5. In the case of image information VC, there is less encoded data for 71 lines, and the encoded data signal and F20L
The total time T with the eccentricity is the minimum transmission time T of the I line mentioned above.
Yu, there is a possibility that it will become smaller by 19. In that case, the encoder 3 inserts a film between the data signal and the EOL signal, adjusts the fill so that T≧T[1, and transmits the signal.

The modulated data Fi is demodulated by the demodulator 7 of the receiving facsimile device 6, decoded by the decoder 8, and recorded by the recording unit 9 according to the decoded image signal. Since the data is inserted, there is a drawback that the transmission time becomes longer. For this reason, as shown in Fig. 2, backup memories are inserted between the encoder and f-unit of the transmitting facsimile machine, and between the demodulator and the transmitter of the receiving side at 7 aximum lengths, thereby reducing the transmission time. The method is being used.

In this case, the encoder uses a coding control station determined according to the white run and black run of the image signal, so the encoded data 1 is different and the encoded data is not output at a constant speed, but it is strange!
1l-a (D Since the modulation speed, that is, the transmission speed is constant, the input/output speeds of the 7-block memory 110 lf#:c are not equal. This subtraction is shown in FIG. 3. This figure shows the temporal change in the image signal encoding processing speed (broken line 21) and transmission speed of the sending side 7 fax machine 10 in the facsimile system.
t is when encoding parameters are determined, t is when transmission starts, t4 is when encoding ends, and tI is when transmission ends. Is the encoding processing speed transmission speed 9? If it exceeds (hatched area 2)
3, 25) The amount of data stored in the backup memory 11 continues to increase, and if the backup memory 11 overflows, all outputs of the encoder 2 will be stopped. Also, if the encoding processing speed is lower than the transmission speed 1ia (Shaded area 22.24.
26) The amount of data stored in the buffer memory 11 continues to decrease, and when the backup memory becomes under 70, the encoder 2ri file (dummy signal) is sent to prevent the buffer memory 11 from becoming empty. □In this method, a fill is inserted into the encoded data signal because the encoding processing speed continues to be lower than the modulation speed (transmission speed a) for several lines, and the backup memory is under 70- Since this method is limited to limited cases, the number of fill generation lines is reduced and the transmission time is shortened compared to the method shown in FIG.

However, at the start of transmission t! For the purpose of determining various parameters, a pre-message procedure is required, and after the pre-message procedure is completed, encoding is started at the same time as the data transmission starts, so the data transmission start time t.

In this case, the backup memory is under 70-, and the image signal read from the RI original at the start of transmission is generally 1. Since the signal is often an all-white signal on the l line, many fills appear and the encoding processing speed slows down (between 1 and tl).

In this way, immediately after the start of transmission, the backup memory is often under 70-, and fills are inserted in several lines immediately after the start of transmission, resulting in a long transmission time.The purpose of the present invention is to solve the above drawbacks. Another object of the present invention is to provide a facsimile communication method that reduces communication time by reducing the number of fill insertion lines immediately after the start of transmission.

According to the present invention, in a facsimile system having a backup memory for storing image signal encoded data in a sending/receiving facsimile device, the sending facsimile device
Start reading and encoding the image signal before starting signal transmission,
A 7-pitch 1-f communication method is obtained in which all data is stored in the Pavf memory and data transmission is started after the data has been collected. By using the present invention, the under-70 state of the Pavf memory at the start of transmission is eliminated. Immediately after the start of transmission, 7 memory? This enables effective utilization, and reduces the number of fill insertion lines immediately after the start of MAYU transmission, thereby shortening the waiting time.

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

5- An embodiment of the invention uses the facsimile communication device Itt shown in FIG. 2, but with the start of operation of the encoder and modulator being different from the conventional case.

FIG. 4 r1 Second facsimile communication method VC according to the present invention
This is a diagram for explaining the communication operation state of the IJ device on the transmitting side of the figure, where the horizontal axis indicates time, t, is the start time of facsimile communication, t is the start time of encoding the image signal, t , is when data transmission starts, t4 is when encoding ends,
tl is the time at the end of transmission, and a is the data transmission speed to the transmission line. Broken line 31r! Encoding when an image signal read from the document ink-picking section of the transmission side 7 axis-printing device is encoded by an encoder also shows a temporal change in processing speed. Therefore, the amount of data to be charged to the backup memory is within the broken line.

Now time 1. When facsimile communication is started, pre-message procedure 1 is performed between the sending and receiving facsimile IJ devices.
◎While the message procedure is being performed (to~1
Encoding of the image signal starts at time t of time t), and all the encoded data is charged to the buffer memory (hatched area 32).
) 6 messages before 6- When the procedure is completed, data transmission to the receiving facsimile machine begins. In this way, encoded data is charged to the memory 1 degree before the start of transmission, so even if the amount of encoded data after the start of transmission is small, the amount of fills sent out is significantly reduced. If there is no underflow in the 7-memory memory from t at the start of encoding to t at the end of encoding, then the encoding processing speed is low enough to store data in the transmitter, 7 am. data (hatched area 3)
2) is the sum of the differences between the transmitted data and the encoded data when the encoding processing speed is slower than the transmission speed a (diagonal line! 35.
37) VC'S.

According to this embodiment Vc, compared to the conventional facsimile communication operation shown in FIG. 3, t≦1. , -11. The communication time is shortened by the time t that satisfies , -11.

As explained above, the present invention starts encoding before the start of transmission and stores the encoded data in the buffer memory, thereby reducing fills immediately after the start of transmission and reducing communication time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional high-speed facsimile device, FIG. 2 is a block diagram of a facsimile device having barrier memory, and FIG. 3 is a conventional communication operation 1i- of the facsimile device shown in FIG. Diagram for explanation, Figure 4 is the 7 techsimile device in Figure 2! FIG. 1 is a diagram for detailed explanation of the present invention using No. 1; 1, 1O old... facsimile transmitter, 6, 16...
Facsimile damage m, 2.11...reader, 3.12 old...encoder, 4,14...modulator, 5゜15...transmitter, 7@17・Old・・Demodulator s 8*19・・Exposure・・Decoder, 9.20・・
-Record section, 13.18...Buff Amezori ◎ Hayabusa 3 figure

Claims (1)

[Claims] In a facsimile communication system having a buffer memory for transmitting image signal encoded data to the transmitting and receiving facsimile devices, the transmitting facsimile device receives the image signal, starts encoding the image signal, and transmits the data. Starting the transmission of the data after it has started to accumulate in the buffer memory 1j-Featured facsimile communication method 0