JPS58218273A - Facsimile signal transmission controlling system - Google Patents

Abstract

PURPOSE:To realize a high-speed picture transmission, by storing at first all picture data in a negative memory when transmitting and connecting a circuit to transmit the picture. CONSTITUTION:A user sets an original to a reading device 1 when transmitting and actuates a controlling part 11. The reading device 1 reads a picture and outputs a binary-coded picture signal which is inputted in a line memory 2, encoded by a band compressing part 3 for every line, performed by the band compression and stored in a page memory 4. Thereafter, the user calls the facsimile terminal equipment of an opposite side and push a communication start button of the controlling part to start the controlling part 11 for starting the transmission. A transmission controlling part 5 reads picture data out of the page memory 4 to supply it to an MODEM 6 and transfers it to the equipment on the opposite side.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field The present invention relates to a facsimile signal transmission control system in which an image on a document is read and transmitted, and this data is restored on the receiving side. Related to signal transmission control method.

(b) Technical background.

A facsimile transmission system is known as a system for transmitting images to a remote location.

This facsimile transmission system generally scans and reads a document to obtain a signal corresponding to the density of the image in each minute area on the document, and then transmits this signal to a line such as an audio line.
A device provided on the receiving side reproduces the signal and records the image on the receiving paper.

On the other hand, transmitting an image signal requires an extremely large amount of information and a wider signal band than voice, so generally the image signal is divided according to certain rules and encoded to compress the band. A method of transmitting at high speed is employed in such facsimile transmission systems.

(C) Prior art.

Conventionally, in facsimile transmission systems, the reading mechanism on the transmitting side and the reproducing mechanism on the receiving side are synchronized, and the speed determined by the speed of the reading mechanism on the transmitting side and the reproduction speed of the reproducing mechanism on the receiving side is determined. The image is sent from the sending side.

::: Also, as a coding method that can transmit image signals at high speed and compressing the band, 2 in CCITT Recommendation T.4 is used.
It is stipulated that different types can be adopted.

One is a method (referred to as Modified Huffman encoding method or MH encoding method) in which a so-called run length, which is a continuous length of the same pixel, is assigned to each code.
A shorter code is assigned to the length that occurs more frequently.

The other is the modified read encoding method (referred to as MR encoding method), which is used in conjunction with the MH encoding method described above, and uses the image signal of the previous scan line to encode each scan line to be encoded. The position of a pixel is encoded based on the amount of difference from the signal change point position adjacent to the position to be encoded in the previous scanning line. - In other words, the MR encoding method encodes only the amount of difference from the image signal of the previous scanning line, and if the amount of difference is small, the MH encoding method is used to achieve higher compression than the high compression rate. The signal can be compressed by the K parameter, that is, the number of scanning lines to be encoded by this method. It is regulated by parameters that specify.

However, in such conventional facsimile transmission systems, when transmitting and receiving signals, both the sending and receiving devices perform the reading operation of the original and the recording operation on the receiving recording paper, which operate at a speed slower than the transmission speed of the line. Since the transmission and reception are performed in parallel, the image must be transmitted at a speed determined by the reading speed of the original and the speed at which the image is reproduced on the receiving recording paper. The disadvantage is that the overall time for image transmission cannot be shortened.

Furthermore, in the conventional technology, the mechanisms are operated in synchronization with each other, that is, once the image signal is transmitted, it is always reproduced, so the above parameters are regulated to small values to reduce errors in the reproduced image. This method has the disadvantage that a large number of codes based on the MH coding method, which has poor compression efficiency, must be sent.

(d) Object of the invention.

The purpose of the present invention is to solve the above-mentioned drawbacks of the prior art.
The object of the present invention is to provide a facsimile transmission control system that can transmit images at high speed.

(e) Key points of the invention.

In order to achieve the above object, the present invention focuses on the fact that high speed can be achieved by configuring the mechanisms on the transmitting side and the receiving side to operate asynchronously, and the present invention has a structure in which the mechanisms on the transmitting side and the receiving side are configured to operate asynchronously.
A memory capable of storing purchased images is provided, and after one page's worth of images is once stored in this memory, this stored image is transmitted from the memory.

(f) Examples.

The drawing is a block diagram of a facsimile transmitting and receiving apparatus according to an embodiment of the present invention. In the figure, 1 is a reading device, 2 is a line memory, 3 is a band compression section, 4 is a page memory, 5 is a transmission control section,
6 is a modem unit (hereinafter referred to as a modem); 7 is a network control device; 8 is a band expansion unit; 9 is a line memory; 10 is a recording unit;
11 is a control section.

The reading device l is a device that scans an image on a document, and mainly has a plurality of four optical sensors arranged in a direction perpendicular to the direction in which the document is transported, and reads the image in the main scanning direction. The sub-scanning is carried out by the movement of the image.

The line memory 2 mainly stores image signals of one scanning line obtained by main scanning, and is constituted by a shift register.

The band compression unit 3 has a main function of encoding the image signal stored in the line memory 2 using the above-mentioned MH and MR encoding power method, and encodes the image signal of the main scanning line at the time when reading the document starts. is encoded using the MH encoding method, and the image signals of subsequent lines are encoded using the MR encoding method. In the MR encoding method by the band compression section 3, the above parameters are set to infinity or, if the size of the transmitted document is constant, to the total number of scanning lines of the document.

The page memory 4 has a storage function that can store at least several pages worth of images. As will be described later, the datum supplied from each means, that is, the image data sent at the time of transmission:): The image data of the original, and the received image data are stored in the four receivers each time they are supplied. In addition, page memory 4
The larger the storage capacity, the more images of documents can be stored, but in normal facsimile systems, one document is the unit of image transfer and is transmitted all at once without waiting for a response from the receiving side. The required capacity may be a storage capacity for one page.

The main function of the transmission control unit 5 is to control the transmission of image signals based on a certain procedure between the transmission control unit 5 and the reception device. (encoding method that can be reproduced by the receiving device, size of reproduction recording paper that the receiving device has, transmission speed that can be reproduced, etc.), or, when this device becomes the receiving side, notifies the function of this device, Furthermore, it has a function of creating a check code for transmission data including image data and adding it to the transmission data for transmission.

When the modem 6 transmits images (signals, control data, etc.), it modulates the carrier and demodulates the received image signal and the signal that has been modulated and transmitted.

The network control device 7 is a device that has the function of switching between the line and a facsimile, and between the line and a telephone (not shown), and furthermore, when a call is received from the line, This is to send back a signal to confirm connection to the line. Although not explained in detail in this embodiment, in response to a command signal from another device such as a timer device, the network control unit 7 sends a dial signal, push button signal, etc. to the called subscriber to the line. It is also possible to provide a function that enables control of transmitting an image signal after transmitting a calling signal and automatically connecting a receiving device to a line.

Bandwidth expansion unit 8 includes bandwidth compression unit 3 stored in page memory 4.
The encoded image data is read out and the image signal is restored line by line and output.

The line memory 9 stores restored image signals for each scanning line.

The recording unit 10 reproduces the image signals of l scanning lines stored in the line memory 9 onto recording paper, and uses known printing means such as recording electrodes arranged perpendicular to the paper feeding direction or a print head. It is something that has.

The control section 11 starts up each of the above-mentioned sections 1 to 10 in a predetermined order.

Next, the operation will be explained.

In this apparatus, when transmitting, all image data is first stored in the page memory 4, and then a line connection is established and the image is transmitted. On the other hand, during reception, the received image data is temporarily stored in the page memory 4, and then the image is reproduced in the recording section 10.

I will explain step by step.

(when sending) 1. The user inserts the manuscript into the reading device 1.

2. The user then activates the control unit 11 by operating an operation unit (not shown).

When activated, the control unit 11 activates the reading device l. The reading device 1 thereby feeds the documents one by one into the device and starts scanning. The reading signal of each scanning line obtained by this scanning is binarized and the reading device 1 outputs an image signal.

The image signal binarized by the reading device 1 is input to the line memory 2, and is encoded every line by the band compression section 3. The band compression unit 3 performs band compression on the image signal by setting the parameters to maximum and the scanning speed to the maximum based on instructions from the control unit 11, and supplies the compressed image signal to the page memory 4. At this time, the control section 11 activates the page memory 4 in advance so that the page memory 4 can directly store the image data output from the bandwidth compression section 3 at high speed.

When one page of image data is stored in the page memory 4, the control unit 1
1 notifies the operating section that the image data has been stored in the page memory 4, and the operating section displays or notifies the user of this fact. In addition, if the capacity of the page memory 4 is increased and the image data of multiple documents can be stored, the image data of all the documents sent to the reading device 1 will be stored in the page memory 4. or page 1.1L mori 4
When it becomes full: 1, the user will be notified as described above.

3. The user uses the telephone to call the other party's facsimile machine. On the other hand, the means for calling the other party's facsimile device may be automatic calling by the network control unit 5 as described above, without having to do this manually.

The user confirms that the other party's facsimile machine has been connected by listening to the answer sound from the network control device 7 provided in the other party's facsimile machine, and presses the communication start button on the operation unit. The control unit 11 is started to transmit by this push signal,
The network control device 7 is instructed to switch from the telephone-line connection to the modem 6-line connection, and the transmission control unit 5 is activated.

As described above, the transmission control section 5 performs the pre-procedure for transmitting the image signal with the other party's facsimile machine. In this pre-procedure, a control signal is sent from the transmission control unit 5 to the receiving device via the modem 6, the network control device 7, and the line.
Alternatively, the control signal sent from the receiving device can be sent to the modem 6.
This is accomplished by receiving from:1.

Upon completion of the previous procedure, the transmission control unit 5 displays the page ``:I''.
l Read image data from the memory 4 and supply it to the modem 6.

At this time, the transmission control unit 5 may transmit all the image data stored in the page memory 4, but it may divide the image data stored in the page memory 4 into sections of a certain number of bytes and transmit each piece of data in units. It may also be transmitted as a frame. In this case, the transmitting side device sends the transmission control unit 5 every time it transfers the transmission frame.
The controller sends control data (check data, flag data, etc.) indicating that the image data has been transferred, waits for a response from the receiver, and each time an acknowledgment is received from the receiver indicating that the image data has been received without error. The image data of the next section may be transmitted.

The modem 6 modulates a carrier wave carrier signal with the image data, and sends a facsimile signal to the receiving device via the network control device 7.

After transmitting the last image data, the transmission control unit 5 supplies the modem 6 with control data indicating that all image data has been transmitted.

As a result, a response is made from the receiving side that all the image data has been received without errors, and when the transmission control unit 5 determines this, the transmission control unit 5 sends control data to the modem indicating that it is okay to disconnect the line. 6. Notify the receiving device via the network control device 7 and the line, and notify the control unit 11. Using this signal, the control section 11 sends a line disconnection instruction to the network control device 7, disconnects the transmitting side line, and ends the operation of the facsimile transmitting device.

(At the time of retransmission) If the unit-divided image data is displaced during transmission and a reception error occurs, the receiving device returns a retransmission request response.

When the transmission control section 5 receives this response, the transmission control section 5 reads out the image data from the page memory 4 again and transmits it.

In this way, it is possible to transmit the image data requested by a retransmission request for each main part of the original or for each page, so even if there is an error in the received data, the receiving side can receive an image that matches the image of the transmitted original. can be played.

5 (When receiving) When receiving, the network control device 7 is first called from the line. Accordingly, the network control device 7 activates the control section 11 and the transmission control section 5, and supplies an answer signal to the line indicating that the facsimile receiving apparatus is connected to the line.

The control unit 11 activates the page memory 4. After executing the above-described pre-procedure via the modem 6, the transmission control unit 5
A received signal output, a so-called received data line, is connected to the page memory 4.

Thereafter, the image data transmitted as described above is stored in the page memory 4 via the network control device 7 and the modem 6. On the other hand, during the period when image data is received, the transmission control section 5 inspects the received data appearing on the above-mentioned received data line in parallel with the data being stored in the page memory 4. As an inspection method, the transmission control unit 5 adds a check code to the image data and sends it out as described above in the transmission control unit on the sending side.
6 methods to check whether there is an error in the image data using this check code.
″″801′47! Various methods can be used to check whether or not 9*h<Ml, 714m.

Furthermore, the transmission control unit 5 monitors whether or not control data indicating a break is output to the received data signal line, detects that the control data indicating a break is received, and transmits the response data to the modem 6.
supply to the transmit data line.

As described above, this response data is inspected by the transmission control unit 5 on the received image data, and depending on the inspection result, either the acknowledgment data or the retransmission request response data is selected. be done.

If a positive response is returned here, the next image signal is transmitted from the transmitting side. The new image data thus transmitted is stored in a new storage area of the page memory 4. On the other hand, when a retransmission request response is returned, the corresponding image data is received again, so the page memory 4 starts retransmitting the data from the beginning of the data storage area of the transmission frame containing the error that has already been received and stored. Store the received image data.

Further, if the control data 11 indicating the end of transmission is received and the image data is received without error, the transmission control unit 5'' returns a response to the transmitting device to the effect that up to this last data was correctly received. When the transmission control unit 5 detects that a control signal indicating a line disconnection instruction has been received from the transmitting device in response to the response, the transmission control unit 5 notifies the control unit 11 of this fact.The control unit 11 thereby performs network control. Activate device 7 to disconnect the line.

Next, the control unit 11 activates the band expansion unit 8.

The band expansion unit 8 converts the image data stored in the page memory 4 into 1
The signal is restored line by line and the restored signal is supplied to the line memory 9. The restoration speed of the band expansion section 8 matches the recording speed of the recording section 10.

The recording unit IO uses the image signal stored in the line memory 9 to move the received recording paper, record and scan it, and reproduce the image of the document at the time of transmission on the received recording paper.

In this embodiment, the image data once stored in the page memory 4 is reproduced on the reception recording paper by starting the band expansion section 8 when the reception is completed. If the facsimile device has a function, for example, when the reception is completed, the receiving user is notified by means of a display means, etc., that the confidential image data has been received, and a specific confidential key, for example, the principal is The reception may be recorded only when a key such as a password for confirmation is input and the key is authenticated using a known authentication technique. Furthermore, in the above embodiment, it has been explained that the facsimile device that receives the image data reproduces the image, but the facsimile device that receives the image data does not only reproduce the image, but also allows other facsimile devices to receive the image. The image data stored in the page memory 4 may be relayed from the facsimile device and the other facsimile device may reproduce the image. In short, the present invention provides the page memory 4 in order to asynchronously perform a slow image generation means such as a reading mechanism or a mechanism for automatically reading a medium on which image signals are already stored, and a means for transferring image data. Any method can be used as long as it is suitable.

(g) Effects of the invention.

As explained in detail above, according to the present invention, image signals can be transferred from the memory without synchronizing the mechanical parts on both the transmitting side and the receiving side. Since the image data is stored in memory, a retransmission method can be adopted, and all images for one document except for the image on the first main scanning line are encoded and transmitted using the MR encoding method, which is faster than the MH encoding method. You can also.

[Brief explanation of drawings]

The drawing is a block diagram of an embodiment of the invention. In the figure, ■ is a reading device, 2.9 is a line memory 3 is a band compression section, 4 is a page memory, 5 is a transmission control section 6 is a modem, 7
is a network control device, L is a line, 8 is a band expansion section, 10 is a recording section, and 1 summer is a control section.

Claims (1)

[Scope of Claims] +11 On the transmitting side, means for generating an image signal corresponding to the image directly above the unit, and at least image data created by the image signal corresponding to the image on the page of the unit are stored. It comprises a transmission storage means, a means for reading and transmitting the image data of the unit page stored in the transmission storage means, and a reception means for reproducing the image on the reception side, the image data generated on the transmission side A facsimile signal transmission control method characterized in that after image data corresponding to a signal is stored in the transmission storage means, the image data is read out from the transmission storage means and transmitted. 4 (2) The reception means includes a reception storage means for storing received image data, and a reproduction means for reading out the stored image data from the reception storage means and reproducing it on a recording medium, A facsimile signal transmission control method according to claim 11, characterized in that image data is transmitted between the two storage means. (3) The image data stored in the transmission storage means is the image signal A facsimile signal transmission control method according to claim 11 or (2), characterized in that the facsimile signal transmission control method is an encoded image of the image stored in the reception storage means. Claim 11, characterized in that the data is decoded to reproduce the image signal, and the image is restored based on the image signal.
), (2), and (3).