JPH05145774A - Image communication method and its equipment - Google Patents

Abstract

PURPOSE:To prevent tapping with a comparatively simple device, and also, to transmit and receive image data by a simple operation. CONSTITUTION:The image communication equipment is provided with a control means 11 having data of several special transmitting/receiving methods, a means 9 for converting a read picture signal by a prescribed transmitting method, and/or a means 10 for restoring a received picture signal by a receiving method corresponding to the transmitting method. In such a state, at the time of transmitting and receiving the picture signal between the image communication equipments, several special transmitting/receiving methods are prepared in advance between the transmitting side equipment and the receiving side equipment, and each function and the transmitting/receiving methods in its transmitting/receiving operations are confirmed each other by a communication procedure operation. Thereafter, the picture signal is sent out by the transmitting method confirmed each other from the transmitting side equipment, and on the other hand, the receiving side equipment decodes a received signal by the method corresponding to the transmitting method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image communication apparatus, and more particularly to an image communication apparatus which simplifies a wiretapping prevention measure for a third party during a communication operation.

[0002]

2. Description of the Related Art In recent years, various image communication devices such as facsimiles have been provided with some measures to prevent eavesdropping on communication contents. There is one disclosed in JP 61-10364. This facsimile is composed of a document reading unit, an encoding / decoding unit, a modem, and a page memory provided between the modem and the encoding / decoding unit. When transmitting and receiving with the regularity of, the page memory is controlled by the page memory control unit that interchanges the image information in the order having the predetermined regularity, the page memory is controlled, and the image signal is reproduced and recorded. It is a thing. Since the image signals are exchanged at the time of transmission, even if there is a third party trying to eavesdrop in the middle of the communication line, completely unknown data will be recorded in the facsimile of this third party, and confidentiality will be kept. Can be prevented to some extent from leaking a large amount of information.

[0003]

However, in such a conventional image communication apparatus, since the transmission order of the image information is switched with a certain regularity, the third method for eavesdropping is attempted. If a person owns a facsimile having the same specifications and the same type and eavesdropping in the middle of a communication line, the facsimile data can be easily reproduced because the regularity is the same. For this reason, the conventional facsimile has not been sufficient in terms of wiretapping prevention.

On the other hand, there is a method of adopting a complicated encryption method in order to make the wiretapping prevention even closer to perfection. For example, there are things like the "FEAL-8" cryptosystem invented by NTT that it takes years for a supercomputer to decrypt, and this is because complicated cryptographic keys are set by each other. The encryption / decryption is performed by performing various operations. However, according to such an encryption method, in order to realize the function, if it is realized by software, a faster processing speed is required for the program, or if it is realized by hardware, it is necessary to prepare a dedicated circuit, Further, since the development period is increased, there is a problem that the cost is increased in both hardware and software.

The present invention has been made in view of the above problems, and an object thereof is an image communication method capable of preventing wiretapping with a relatively simple mechanism and capable of transmitting and receiving image data by a simple operation. It is to provide a device.

[0006]

In order to achieve the above object, the present invention provides an image communication apparatus including an image reading section, a recording section, and a communication control section for controlling a transmission / reception operation of an image signal. Control means having the data of the special transmission / reception method, means for converting the read image signal by a predetermined transmission method, and / or restoring the received image signal by a reception method corresponding to the transmission method. The point is that the means is provided.

[0007]

When the image signal is transmitted and received between the image communication devices,
Some special transmission / reception methods are prepared in advance between the transmission side device and the reception side device, and the data of this transmission / reception method is stored in the memory built in the control means. Regarding the communication procedure, in phase B, mutual functions and transmission / reception methods in their transmission / reception operations are determined and confirmed. After that, in the transmission side device, the control means instructs the signal conversion means at the time of the communication operation to the transmission method confirmed with the partner side device. For this reason, the image signal is transmitted from the transmission side device by the above-mentioned mutually confirmed transmission method. On the other hand, in the receiving side device, the control means instructs the signal restoring means on the reception method confirmed with the partner side device during the communication operation. Therefore, the receiving side device decodes the received signal by the above-mentioned mutually confirmed receiving method. As a result, the transmission / reception method can be divided into a plurality of types, and the transmission / reception method can be changed for each communication operation. Therefore, even if an attempt is made to eavesdrop using the image communication apparatus of the present invention, it is difficult to find out the content of the transmission / reception method, and eavesdropping by a third party becomes almost impossible.

[0008]

1 and 2 are diagrams showing an embodiment in which the present invention is applied to a facsimile which is an image communication apparatus. Figure 1
In FIG. 1, reference numeral 1 is an image reading unit that reads an original to generate image data, 2 is an image memory as a memory member that stores and expands the image data read and input by the image reading unit 1, and 3 is an image to be transmitted. An encoding / decoding unit 4 that performs data encoding processing and also performs decoding processing of received encoded data, and 4 is an image recording unit that outputs the image data stored in the image memory 2 as a hard copy. Reference numeral 5 denotes an operation display unit provided with various keys and a display unit for setting various modes for operating the facsimile.

Reference numeral 6 is a modem for performing modulation / demodulation processing of encoded image data for image data transmission, and reference numeral 7 is a built-in network control for dialing operation to control communication with the line 8 and to perform predetermined transmission. It is a communication control unit that realizes facsimile transmission according to a control procedure. Further, reference numeral 9 is a signal conversion unit that converts the read image signal according to a predetermined transmission method, and 10 is a signal restoration that restores the received image signal according to a reception method corresponding to the transmission method of the signal conversion unit 9. Reference numeral 11 denotes a system control unit for controlling the operation of the entire facsimile according to this embodiment. Further, reference numeral 12 is an eavesdropping device which attempts to eavesdrop on the line 8 during the communication operation of the facsimile of this embodiment.

In this embodiment, the image reading section 1 is equipped with, for example, a CCD image sensor for converting an optical signal obtained by reading a document into an electric signal. Also,
The image memory 2 has a function as a page memory, for example, and stores the image data read and input by the image reading unit 1 in page units and expands it, or has a function as a line memory. The image data recorded by the image recording unit 4 is temporarily stored for each line. In addition, the system control unit 11
Is composed of a CPU and the like, and the system control unit 11 is provided with a memory for storing data regarding some special transmission / reception methods.

The operation of the image communication apparatus having such a configuration will be described below with reference to FIG. In the facsimile transmission / reception operation, the operator of the facsimile machine on the transmission side (hereinafter referred to as the transmission terminal) sets the transmission original in the image reading unit 1, inputs the designation of the wiretapping prevention mode or the like from the operation display unit 5, and further After inputting the telephone number of the transmission destination, similarly, when the operation display unit 5 is instructed to start the transmission, the system control unit 11 transfers the input destination telephone number to the communication control unit 7 and issues an instruction to call the destination. To do. Accordingly, the communication control unit 7 transfers the destination telephone number to the built-in network control unit and dials the destination. As a result, a calling / non-voice terminal representing the calling non-voice terminal is sent from the sending terminal to the destination facsimile machine (hereinafter referred to as the receiving terminal).
A tone, that is, CNG, is sent out, and the receiving terminal that receives the tone sends back CED, which is the called terminal identification signal, to the transmitting terminal, and the line 8 is established.

When the destination is called and the line 8 is established, the receiving terminal displays the called terminal by the NSF (non-standard function identification signal) which is a transmission function indicating signal of the receiving terminal and the international telephone number to the transmitting terminal. CSI (Called Terminal Identification Signal) and DIS (Digital Identification Signal) indicating that the called terminal has a standard receiving function are transmitted. At this time, data indicating that the receiving terminal has a function corresponding to the special transmission / reception method for wiretapping prevention adopted in the present invention is added as NSF data.

When the transmitting terminal receives each of the above signals, the transmitting terminal controls the transmitting terminal by NSS (non-standard function setting signal), which is a command signal indicating a function to be set among the non-standard functions displayed by the NSF signal. The TSI (transmitting terminal identification signal) to be displayed is transmitted to the receiving terminal. In this NSS, according to the non-standard control procedure of Phase B, a simple operation, for example, simply adding the data (for example, ID, password, etc.) sent from the receiving terminal and the data set on the sending side, exclusive, Data such as determining the end number as the "transmission mode" number by taking logical OR is added to the receiving terminal to inform the receiving method of the transmission method to be used for the facsimile transmission and reception. In some cases, the transmission mode can be changed by changing the setting data from the transmitting side every time transmission is performed, and the receiving side can also change the data from time to time. Of course, a method such as no notification of a special transmission mode is also included in one implementation means.

FIG. 3 shows a specific example of the transmission mode. FIG. 3A shows that "
This is a method of inverting 1 "and" 0 "and transmitting.
(B) is a method of sending data in one line in reverse. FIG. 3C shows a method in which the order is changed every two bytes and the data is sent. In addition to this, there is a method of exchanging lines. In addition, in the transmission mode, as shown in FIG.
There is also a method of combining and repeating the method of (c). These data are stored in the memory of the system control unit 11 as described above, and the data in the memory can be updated from time to time.

When the transmission mode is determined by the exchange of the NSF signal and the NSS signal, the transmission terminal outputs a TCF (training check signal) to the reception terminal to confirm the training of the modem 6, and the reception terminal. In response to this, sends back a CFR (reception preparation confirmation signal).

As a result, image information can be sent and received between both terminals, and a facsimile message, which is a message, is sent from the sending terminal to the receiving terminal.
The receiving terminal receives this facsimile message. In the transmitting terminal, the image data read by the image reading unit 1 is coded by the encoding / decoding unit and then sent to the signal conversion unit 9 where signal conversion is performed according to the previously determined transmission method. It Then, the converted image signal format is modulated by the modem 6 and transmitted to the line 8 by the communication control unit 7. In the receiving terminal, the image signal received by the communication control unit 7 is demodulated by the modem 6, and the signal restoration unit 10
At, the restoration process corresponding to the transmission method is performed.
Then, the restored image signal is decoded by the encoding / decoding unit 3 and then output as a hard copy from the image recording unit 4 or displayed on a display screen.

Thus, in facsimile communication,
Since the image signal is converted and restored, reference numeral 12 in FIG.
Even if an eavesdropping device as shown in FIG. 6 is connected in the middle of the line 8 and takes in a signal, the reproduced signal cannot be read and cannot be eavesdropped.

When the transmission of one unit (for example, one page) of the facsimile message is completed, the transmitting terminal outputs an MPS (multi-page signal) indicating the end of the page of the facsimile message, and the receiving terminal receiving this outputs the MPS. MCF indicating that the message was completely received
(Message confirmation signal) is returned. Then, the facsimile message is subsequently transmitted from the transmitting terminal. Hereinafter, the above operation is repeated until all the image information is transmitted.

When all the facsimile messages have been transmitted, the sending terminal outputs the end of page of the facsimile message and EOP (procedure end signal) indicating that there is no other document to be sent, and this is received. The receiving terminal returns the MCF, and the transmitting terminal outputs DCN (disconnection command signal) indicating the end of operation and requiring no response. As a result, the line 8 is disconnected at each of the transmitting terminal and the receiving terminal.

[0020]

As described above, according to the present invention,
In the image communication device, a control means having data regarding some special transmission / reception methods, a means for converting the read image signal into a signal according to a predetermined transmission method, and / or a received image signal in the transmission method. Since the means for restoring according to the corresponding receiving method is provided, the image data can be reproduced only between the communicating image communication devices to prevent eavesdropping by a third party or to communicate to another person by the wrong call. Various effects can be obtained such that the contents are not known.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment in which an image communication apparatus according to the present invention is applied to a facsimile.

FIG. 2 is a flowchart for explaining the operation of the above embodiment.

FIG. 3 is a diagram showing an example of a transmission mode in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 image reading unit 2 image memory 3 encoding / decoding unit 4 image recording unit 5 operation display unit 6 modem 7 communication control unit 8 line 9 signal conversion unit 10 signal restoration unit 11 system control unit (control means) 12 eavesdropping device

Claims (3)

[Claims] 1. When transmitting / receiving an image signal between image communication apparatuses, some special transmission / reception methods are prepared in advance between the transmission side apparatus and the reception side apparatus, and the communication procedure is performed in phase B with each other. Function and the transmission / reception method in the transmission / reception operation, and then the image signal is transmitted from the transmission side device by the confirmed transmission method, while the reception side device transmits the reception signal by the method corresponding to the transmission method. An image communication method characterized by decoding. 2. An image reading unit, means for converting the read image signal according to a predetermined transmission method, a communication control unit for sending the converted image signal onto a communication line, and some special features. And a control unit having data relating to a transmission / reception method, wherein the control unit determines and confirms the transmission / reception method with the partner device during communication operation, and transmits the confirmed transmission method to the signal conversion unit. An image communication device characterized by giving an instruction. 3. A communication control unit for receiving an image signal sent through a communication line, a unit for restoring the received image signal according to a predetermined receiving method, and a unit for outputting the restored image. And a control means having data relating to the special transmission / reception method, wherein the control means determines and confirms the transmission / reception method with the partner device at the time of communication operation, and this confirmation is made to the signal restoration means. An image communication device characterized by instructing a receiving method.