JPS61135275A - Facsimile communication system - Google Patents

Abstract

PURPOSE:To attain transmission of picture information in a short time by informing the time corresponding to the writing speed of picture information to a memory means to the transmission side in the form of the minimum transmission time in a reception mode of picture information and in case the memory means has a margin of capacity. CONSTITUTION:The received coded and compressed picture information data is stored temporarily in a DRAM40 and then transferred to a code reproducer 34. The reproducer 34 reproduces the picture information data. This reproduced data is transferred again and stored in the DRAM40 under the control of a DMA control part 48. Then the stored data is read out by the part 48 and transferred to a picture recorder 20. The recorder 20 delivers the data in the form of a hard copy. In this case, the DRAM40 informs the writing speed to the DRAM40 not the picture output speed of the recorder 20 to a transmission station device as long as the DRAM40 has a margin of capacity. While the transmission station device transmits the picture information data at the writing speed to the DRAM40. Therefore, the data can be transmitted at a high speed even in case the output speed of the recorder 20 is lower than the data transmission speed. This improves the overall transmission efficiency of a facsimile communication system.

Description

[Detailed description of the invention] 1. The present invention relates to a facsimile communication system, and particularly to a facsimile communication system having an image information storage function.

Conventional IL Technique Conventionally, some facsimile systems designed for high speed and high performance have a store and forward (sAF) function for storing and transmitting image information. When image information is received by a facsimile device having such a storage and transfer function, the received image information is temporarily stored in an image information storage area, and then visualized and output as a /\-tocopy from the recording device.

Generally, facsimile communication is set up according to a communication method based on the CCIT↑ recommendation, for example, the G111 communication method. For example, when a facsimile machine operates as a called station, it uses a "digital identification signal (DIS)" as an initial identification signal.
) J is sent back from the called station to the calling station. As is well known, this DXS signal has a function of reporting the performance of the called station apparatus to the calling station apparatus, and includes the minimum transmission time of the called station apparatus.

This is expressed as the transmission time of image information for l scanning lines.

In conventional facsimile machines, even if they have a storage and transfer function, the hard copy output speed of the recording device included therein is reported as the minimum transmission time. Generally, the output speed of a recording device is much slower than the writing speed to memory.

There is a high possibility that there will be free space in the storage area that temporarily stores the received image information, and even if there is such space, the reception of the image information will be limited by the slow output speed of the recording device. Therefore, the transmission time will be short. It was not possible to efficiently transmit image information.

It is an object of the present invention by Watari-ichi to provide a facsimile communication system that eliminates the drawbacks of the prior art and allows image information to be transmitted in a short transmission time.

In order to achieve the above object, the present invention includes a storage means having a storage capacity capable of temporarily storing image information of a predetermined funeral position, and a recording means for outputting the received image information as a visible image. However, in a facsimile communication system that transmits image information according to the transmission time notified to the sending side as the minimum transmission time included in the initial identification signal of the communication control procedure at the start of image information transmission, when image information is received, storage When there is sufficient storage capacity of the storage means, the sending side is notified of the time corresponding to the writing speed of image information to the storage means as the minimum transmission time, and when there is no storage capacity of the storage means, the minimum transmission time is reported. The present invention is characterized in that a time corresponding to the output speed of image information in the recording means is reported to the transmitting side. Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

Referring to the figure, a document reading device WI 18 and a document recording device 20 are respectively connected to a system bus (CPυ bus) 12 of a central processing unit w (CPU) io.

As will be described later, the CPt 110 performs high-level control of the entire apparatus, and is advantageously constructed of, for example, a YACRO processor. System bus 12 includes a data bus, an address bus, and a control bus.

The drawing reading device 18 is a device that reads a document image and inputs the image information to this device as bit data.
The calligraphy and image recording device 20, which includes a document conveying system for reading a document, a reading optical system, an illumination system, an electrical system, etc., is an image information recording device that records image information as bit data as a hard copy, and is an image information recording device that records image information as bit data as a hard copy. Includes transport system and recording system.

An operating unit 22 is connected to the system bus 12 as an interface with an operator, and a keyboard 24 is connected to the bus 12 via an interface 2B and a display 28 is connected to the bus 12 via a display control unit 30. 0 indicator 28
The characters displayed are generated by a character generator 31, which is also connected to the system bus 12, in the form of, for example, a dot pattern.

This device includes an encoding and compression device 32A as an image information processing section.
and 32B, code reproducing device 34 and image processing section 3B
, which is also connected to the system bus 12. The encoding/compressing devices 32^ and 32B are devices that remove redundancy of image information and encode/compress using data compression algorithms such as Modified Huffman (MH) and Modified Read (MR), and have a plurality of compression algorithms. . Further, the code reproducing device 34 is a device that decodes and expands encoded and compressed image information data and reproduces the code into the original data, and also has a plurality of reproduction algorithms such as reduction, enlargement, linear density conversion, etc. of 0-picture information. Image processing is 1
This is performed in the image processing section 3B.

The device has a communication control unit (COO) 3B, which is also connected to the system bus 12. , ccu 38
The external communication line 39 is accommodated, and the receiving side device connected through the communication line 38 is provided with, for example, GCI
It executes communication protocols such as the GIII standard based on the TT recommendations, and also has modulation and demodulation functions.

As a system storage device, (IRAM 40.CM
OSRAM 41 and ROM 42 are system bus 1
2, and the DRAM 40 mainly stores image information data such as calligraphy information data and encoded data, as described later.
It is also used as a storage area for temporary storage of data stored on a floppy disk 50, which will be described later.

This storage area is used not only as a data buffer between the constituent units connected to the system bus 12, but also as an area for storage and transfer (SAF) of single-picture information data. A part of it is also used as a FIFO for adjusting the transfer rate between units.

In this embodiment, the CMO9RAM 41 is a storage device backed up by a backup power source such as a battery, and stores management data of this system.

The ROM 42 stores a control program for this device executed by the CPU 1G and fixed data.

A clock 44 is connected to the system bus 12, which is
This is a calendar clock unit that manages the date and time of this device.

This date and time information is transferred from the display control section 30 of the operation section 22 to the display 28 and displayed once. Further, if necessary, it is converted into a dot pattern by the character generating section 31 and superimposed on the image information.

In a non-system, data can be transferred directly between each component unit at high speed without using the CPU 10 via the system bus I2-H. Such direct memory addressing is performed by the DMA control unit 4B.

This system has a floppy disk 50 as a file storage device, which is connected to a system bus 1 via an interface 54 and a floppy disk controller 58.
Connected to 2. For example, image information is stored in these file memories.

By the way, the operation of transmitting image information by this device will be explained.

When the image information of the document is read by the image reading device file, this information is transmitted to the DNA control unit 4 regardless of the CPU.
Under the control of the day, the data is transferred to the DRAM 40 and stored in its SAF area. The image information data stored in the DRAM 4G is transferred to the encoding/compressing device 32^ or 32B by the DMA control unit 4B.

In the encoding/compressing device 32A or 32B, the redundancy of the image information data is removed by a predetermined algorithm, and the image information data is compressed and encoded. This data is again transferred to the DRAM 40 under the control of the DNA #J controller 48 and temporarily stored in its FIFO 2 area.

By the way, the clock 44 manages the system time, and for example, when the time set in the CPU 10 arrives, the COO 38 sets up a connection with the called device through the communication line under the control of the CPU 1G.

Once this connection is set up, the DMA control fi48
The compressed data stored in the FIFO of the RAM 40 is read out using first-in-first-out (FIFO) and transferred to the CCU on the third day. This FIFO area is connected to the encoding/compressing device 32A or 32B (:, C113
The function is to match the processing speed of 8. DRA
The encoded data transferred from M 40 is transferred to CCU 38
The signal is modulated by and sent to line 39.

In this way, the image information data is transferred at high speed on the system bus 12 mainly under the control of the DMA control section 48, and a transmission operation is performed. As you will see, the encoding/compressing device I32 not only performs encoding and compression for transmitting image information data to one line, but also performs encoding and compression for storing image information data in the DRAM 40 and floppy disk 50. is also used.

On the other hand, the CPo 10 sends, receives, and processes high-level commands such as reading start instructions and recording start instructions to the calligraphy reading device 18 and calligraphy recording device 20, and the responses thereof, and performs encoding to the encoding and compression devices 32A and 32B. Start, stop commands, data management of DRAM 40, D
It controls the entire system, including controlling the MA control unit 4B and instructing the C(A 38) to start and end communication procedures.

By the way, even if a protocol is established between the called station and the called station using CCTJ 38, if the compression method, linear density, or document size of the image information data compressed and stored in the DRAM 4G differs from that of the called station, the image Transmission of information becomes impossible. Therefore, it is necessary to match different requirements among the two to the partner station equipment, but this system is made possible by doing this in the following manner.

First, the image information data is read out from the DRAM 40 to the code reproducing device 34, the code is reproduced, and the image information data is read out from the DRAM 40 again.
Next, this image information is read out from the DRAM 40, encoded and compressed in accordance with the conditions of the called station by the encoder/compressor 32A or 32B, and stored in the DRAM 40 again. This re-encoded and compressed image information data is stored in DRAM 4G by CCAJ 38.
It is sent to line 39 from

Of course, data transfer between each of these two systems.

This is performed at high speed by the DMA control unit 48. Also, D.R.
In this way, the AM 40 is used for various purposes as a puffer memory for speed matching in data transfer between the code reproducing device 34 and the coding/compressing device 32A or 32B, and between the coding/compressing device 32A or 32B and the CCU 3B.

When receiving image information data from a communication line, first
IJ 38 responds to this and notifies CPU IO of data reception. The CCU 38 advances the communication control according to the reception control procedure and receives the received image information data j↓,
Although it is in encoded and compressed form, the DMA control unit 48
The data is transferred to the FIFO@ area of the DRAM 40 under the control of , and is temporarily stored there.

The image information data stored in the DRAM 40 is transferred to the DR again.
AM 40 and transferred to the code reproducing device 34. The code reproducing device 34 reproduces this code compressed data, and transfers it to the DRAM 40 again under the control of the DNA control unit 48, where it is decremented. DMA uniform 18 calls this D
It is read out from the RAM 40 and transferred to the calligraphy/image recording device 20. The calligraphy recording device 20 outputs this as a hard copy. As you will see, when the code reproducing device 34 receives image information data from one line.

It is used not only for reproducing the code for the DRA but also for reproducing the code for storing image information data in the DRA 40.

Note that the image information data stored in the DRAM 40 is retained at least until it is confirmed by the plotter 20 that a hard copy has been normally formed.

During the incoming call operation, image information is thus stored in the DRAM 4G. In addition to this, the calligraphy and drawing reading device 1B
The image information is also read from and stored in the mouth RAN 40, and at this time, encoding and compression by the encoding and compression devices 32A and 32B and storage in the DRAM 40 can be performed simultaneously.

It is also possible to read new image information from the reading device 18 and store it in the DRAM 40 while converting the linear density of the image information data stored in the DRAM 40 and transmitting it.

In that case, one encoding/compressing device, for example 32A, performs encoding and compression for transmission, that is, linear density conversion in this case, and the other encoding/compressing device 32B stores new image information data in the DRAM. Encoding compression for storage into 40 is performed.

In this embodiment, Ce11 3B executes a communication control procedure according to a facsimile communication method based on the CCITY recommendation, for example, GIII. According to this, when this device functions as a receiving station device, when a call is received from the telephone line 38, phases 1 to 5 proceed sequentially, but as is well known, at the beginning of phase 2, the signal port IS or A standard equipment signal (N!1ltF) is sent back to the originating station. This is to notify the transmitting station of various functions of the receiving station device.

The 21st to 23rd bits of the signal DS indicate the minimum transmission time of the scanning line. With traditional facsimile machines,
The possible reception speed was set in these bits based on the l scanning line recording time in the calligraphy recording device and returned.
The originating station device selects a mode that matches its own conditions from the opportunity conditions returned by the signal port IS, sets it in the digital command signal (DO3), and notifies the destination station.

However, in this embodiment, when one device is the called station device,
When there is free space in the received image information storage buffer area of the DRAM 40, the writing speed of the DRAM 40, rather than the recording speed of the image recording device 20, is set to the 21st to 23rd bits of the signal DIS as the above-mentioned possible receiving speed. do. The 21st to 23rd bits are expressed in milliseconds,
This memory storage speed is usually sufficiently faster than the image information transmission speed, and these 21st to 23rd bits are set to 0 milliseconds in this case.

When such a signal old S is returned, the transmitting station device receives the signal DI
A mode that matches the conditions of the own station is selected from the functional conditions included in S, and this is set in a digital command signal (OCS) and notified to the receiving station. In the transmitting station device, the image information read from the document/image reading device 18 is temporarily stored in the DRAM 40, so as long as this image information is read from the DRA)I 4G, ■ O milliseconds is set as the minimum scanning line transmission time. With this, image information can be sent.

In the transmitting station device, even if the image information read from the document/image reading device 18 is sent directly to the line 38, there is no contradiction in operating with the minimum transmission time of 0 milliseconds per scanning line, and the compressed image information data Additionally, fill pits may be inserted every scan line to match the transmission data rate to the input rate of the reader 18. Also, compared to the generation speed of compressed data! 138, the accumulated compressed data is read out from the DRAM 40 and sent to the CCU.
When transferring data to CCU 3B, there is a high possibility that the ;J end area of DRAM 40 will become empty.
In step 8, fill pits may be inserted into the transmitted image information data.

In this embodiment, the control of phase 4 (procedure for confirming the end of message transmission) by the multi-page transmission procedure in the G111 communication system will be explained with reference to the flowcharts illustrated in FIGS. 2 and 3. These controls are mainly executed by the CCU 38 in the facsimile machine of the transmitting station or the receiving station based on the control of the CPU IO.

In the transmitting station device, in phase 4 of multi-page transmission, when the transmission of the message for one page of the original is completed,
Sends a biplane signal (MPS) as a post command message to the receiving station and returns to phase 2 (200),
In multi-page reception, when the receiving station device receives the biplane signal MPS, the procedure end signal (EOP), and the message end signal (EOIII) (100), the DRAM
If it is being stored in the DRAM 4G storage area (102), when image information data from the next page is received, it is checked whether there is enough free space to store it in the DRAM 4G storage area (104). For example, the normal phase 2 (
After setting up the call, return to the procedure before transmitting the message).

If there is not enough space in DRAM 40, recorder 2
It is determined whether the hard copy outputted from 0 is good (10B).Next, in this embodiment, a mode change request signal (NCR) J is sent from the receiving station device to the transmitting station as a post message response. and requests the transmitting station to change the mode. At this time, if the image quality of the copy output from the recording device 20 is good, a "mode change request affirmative signal (NC
R-P) J is sent out (+08), and if it is defective, the mode change request negative signal (NCR-N) is sent out (1
12).

Therefore, the control of the receiving station device returns to phase 2, but the minimum transmission time included in the signal DC5 returned from the receiving station device to the transmitting station as a response to the initial identification signal DIS in phase 2 is not recorded in the recording device 20. The actual output speed at which information is output as hard copy is set.

On the other hand, in the transmitting station device, as shown in FIG.

When the signal MPS is transmitted (20G), it is determined whether the received image information data includes a message confirmation signal MCF, a reception confirmation retraining request signal RTP, a reception failure retraining request signal RTN, etc. (202
), if these are not included, it is determined whether the signal NCR-P or IIIcR-N is included (204), and if neither is included, the line disconnection command signal DON is sent ( 20B) Disconnect the line (20B).

If either signal NCR-P or NCR-H is included, the process returns to the beginning of phase 2. That is, the initial identification signal is received again from the receiving station device, and the minimum transmission time of the receiving device is determined again. In response to this, the image information data transmission speed of the transmitting station device is set. In other words, this indicates that there is no free space in the 0RAPI 40 of the receiving station device, and the transmission rate of the transmitting station device is set to the hard copy output speed of the recording IIc of the receiving station device. Therefore, in the receiving station device, the data buffer area of the DRAM 401 does not overflow, image information is sequentially recorded in the recording device, and the free space in the DRAM 40 gradually expands.

As the free storage area expands in the DRAM 40 of the receiving station device, control returns to phase 2 in the receiving station control step 104, and in phase 2, the signal DIS is set to 0 again.
By setting 89 seconds and sending it back to the transmitting station, the DRAM
The transmission of the image information data can be resumed at the writing speed of 40.

As described above, according to this embodiment, the receiving station device has the ORAM 40 for storing a large amount of calligraphy information, and as long as there is a remaining storage capacity in the ORAM 40, the image output speed of the calligraphy recording device 20 is not affected by the image output speed of the DRAM 4G. The transmitting station device transmits image information at this writing speed. Therefore, even if the output speed of the recording device 20 is slower than the transmission speed of image information data, Image information data can be transmitted at high speed, improving the transmission efficiency of the entire system.

Generally, a recording device having a high output speed has a complicated structure and is expensive. On the other hand, with the rapid development of semiconductor memory technology, it is now possible to supply semiconductor memories with larger storage capacities, for example, about 1 megabit, at increasingly lower prices. Using such a semiconductor memory, the system as a whole has a simple and compact configuration, and although it has a low-speed image information recording device, it is equivalent to or even faster than a system that has a high-speed recording device. A facsimile device that can achieve high transmission speeds is realized.

Furthermore, the memory for storing and forwarding image information (SAF), that is, the DRAM 4G in the embodiment, is always used efficiently.

Effect--1 According to the present invention, image information can be transmitted at the writing speed to the storage device even though the image information storage device on the receiving side has a margin. Therefore, image information can be transmitted in a short transmission time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a facsimile communication system according to the present invention, and FIGS. 2 and 3 show the following in the embodiment shown in FIG.
FIG. 7 is a flow diagram illustrating control in phase 4 according to a multi-page transmission procedure in the GIII communication system. 10, central processing unit 12, system bus 1B, document reading device 20, document recording devices 32A, 32B, encoding and compression device 34, code reproducing device 38, communication Control device 4G, , DRAM 48, , DMA control section Fig. 2 Fig. 3

Claims (1)

[Scope of Claims] A storage means having a storage capacity capable of temporarily storing image information in a predetermined unit, and a recording means for outputting the received image information as a visible image, and communication at the time of starting transmission of the image information. In a facsimile communication system that transmits image information according to a transmission time notified to the sending side as a minimum transmission time included in an initial identification signal of a control procedure, when image information is received, when there is sufficient storage capacity in the storage means. notifies the sending side of the time corresponding to the writing speed of image information in the storage means as the minimum transmission time, and when there is not enough storage capacity of the storage means, the minimum transmission time is the time corresponding to the writing speed of the image information in the recording means. A facsimile communication method characterized by reporting a time corresponding to the information output speed to the sending side.