JPH071918B2 - Data communication device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a data communication device, and more particularly to a data communication device applicable to a communication system in which communication cannot be performed for longer than a communicable time.

2. Description of the Related Art Conventional wired or wireless communication systems with a limited communication time generally include, for example, coin-type or card-type pay public telephones. System to use,
For example, there is the MCA (multi-channel access) method.
In these methods, the communication connection is forcibly disconnected after the available communication time elapses.

In the MCA method, the communication connection is forcibly disconnected after a predetermined length of communication time has elapsed.

In a call using a public telephone, the available call time depends on the amount of coins inserted, that is, the amount of money, as is well known. When the rest of the callable time reaches a predetermined amount, for example, the remaining frequency becomes one, an audible warning signal for notifying the caller that the remaining time is short is sent to the line. If additional coins are inserted, communication time will be extended. If additional input is not made, the line connection will be disconnected as the communication time elapses.

Therefore, when facsimile communication is performed by such a communication method, the line connection may be disconnected during the communication, for example, while transmitting a page with a document. If you want to send the rest of the manuscript, you must perform another operation to request a call connection. This operation includes various manual operations such as sending identification information (subscriber number) of a communication partner, setting a document on a reading unit, and setting a linear density at the time of sending. These operations may be almost the same as what was done when the original was first sent, so for the operator it is
On the contrary, not only is it troublesome, but the communication time as a whole is long, and the operability of the device is deteriorated.

It is troublesome to set the original again in the reading unit when retransmitting. In particular, it is difficult to determine which part of the document has been transmitted in the previous communication. Moreover, even if it can be judged, if the retransmission is started from the next part, the receiving side should judge the continuity between the information received in the previous communication and the information received in the communication after the restart. Is difficult. That is, it is difficult to determine whether or not there is information loss in the meantime and whether or not the information of the previous communication and the information of the re-communication are information having a series of the same document.

Therefore, there is a demand for a method in which information is reliably and efficiently transmitted even in such a communication system having a limited communication time, and the entire system is efficiently used.

Aim The present invention has been made in view of such a demand, and an object thereof is to provide a data communication device capable of reliably transmitting information by a simple operation.

In order to achieve the above object, the present invention provides a data communication device that cannot communicate for longer than a communicable time, a time limit means for counting an elapsed time from the start of communication, and monitoring a predetermined time limit, and untransmitted information. The detection means for detecting the remaining time, and when the time limit means reaches the predetermined time limit, there is a determination means for determining whether to continue or end the communication based on the detection result of the detection means. If it is determined that the communication is to be terminated, the predetermined communication termination procedure is performed to disconnect the communication line, and when the communication is restarted, the transmission of the untransmitted information is executed. It is a thing.

In this specification, the term "data" is to be interpreted in a broad sense, including not only digital data in a narrow sense, but also analog image information such as facsimile information and voice information. Hereinafter, a specific description will be given based on an embodiment of the present invention.

Facsimile communication can be performed by connecting a facsimile device to a coin-insertion type or card insertion type general public telephone. Further, by providing the facsimile apparatus with a control mechanism that imposes restrictions on the communicable time and the frequency by paying a fee by inserting a coin or inserting a card, facsimile communication with restricted communication time can be performed. In the latter case, the facsimile function and coin-type or card-type public telephone function are provided in a single device, and facsimile communication and voice communication can be performed as a pay public telephone.

In such a system, the available call time depends on the amount of coins inserted and the remaining amount recorded in the code. When the remaining available time reaches a predetermined frequency, a warning signal is sent to the line. When it is desired to continue the communication, if a coin is additionally inserted, the communication available time is extended, but if the additional coin is not inserted, the line connection is disconnected as the communication available time elapses.

2. Description of the Related Art There is a conventional facsimile apparatus in which a document is conveyed from a document reading unit, and if the communication is disconnected while transmitting document information, the document is discharged from the reading unit. If the document is discharged in this way, the untransmitted portion becomes unclear when the untransmitted portion is to be transmitted next. Also, when receiving the untransmitted part,
The manuscript had to be set again in the reading unit, and various manual operations such as sending the subscriber number of the other party and setting the transmission line density had to be performed.

However, in this embodiment, when the communication is disconnected during the transmission of the document information, the document is held in the reading unit in the same position as it is, leaving the untransmitted portion. Next, when transmitting the remaining document, the document held in the reading unit is conveyed in a reverse direction by a predetermined amount, and the document information is transmitted again from that position. At the time of re-transmission, a smaller number of operations than those at the time of the initial connection setting, for example, one or two button operations, automatically re-call the same destination and request a connection to the communication network. As a result, the user's operation is simplified and reliable information transmission is realized.

Referring to FIG. 1, in an embodiment of the data communication apparatus according to the present invention, the facsimile apparatus 100 has a line interface (I / F) 130, and is connected to a line through this. In the present embodiment, the line may be, for example, an MCA communication system line in which the use of radio waves is time-limited, or a public telephone line that allows a call time according to the amount of coins inserted and the record balance of the card. However, the present invention is effectively applied not only to these communication systems but also to any wireless or wired communication system with a limited communication time.

The signal line 102 from the line interface 130 is the modulator 104.
And is connected to the encoder 108 via the buffer 106. The buffer 106 is a memory that temporarily stores facsimile data to be transmitted. The modulator 104 is a modulator that modulates a facsimile signal to be transmitted by a predetermined modulation method. The encoder 108 is an encoding circuit that frames a facsimile signal to be transmitted and compresses and encodes it according to a predetermined encoding method.

The facsimile data to be transmitted is sequentially read by the photoelectric conversion element 324 of the reading unit 116 from the original 300 (FIGS. 3 and 4) by raster scanning, and stored in the line buffer 118 in units of one sub-scanning line. This is the line buffer 118
Are sequentially read out from the encoder to the encoder 108 and transferred to the buffer 106 through the encoder 108.

As shown in FIG. 3, the reading unit 116 has a mechanism in which a document 300 placed on a document tray 302 is separated by a separation roller 322.
Then, the sheets are separated one by one, and are sequentially conveyed by the conveying roller 306 toward the reading position P2. At the reading position P2, a fluorescent tube 308 is arranged below the target glass 312, and the emitted light 326 thereof is reflected by the image information carrying surface of the original 300 to form a mirror.
It is configured to enter the photoelectric conversion element 324 via 310. A document holding plate 318 is provided on the target glass 312 so as to cover it, and the gap between them is set to the document 300.
Is passed and is discharged to the document discharge tray 314 by the discharge roller 316.

The original 300 is normally conveyed in the direction of arrow A1 by a conveying roller 306 driven by a pulse motor (PM) 132 (FIG. 1). Further, at the time of re-transmission after disconnection of the communication, the transport roller 306 is driven in the opposite direction and is transported by a predetermined amount in the direction of arrow A2. Pulse motor 132
Are driven by the pulse motor drive unit 134, and the latter is controlled by the pulse motor control 138 controlled by the system control unit 136.

Immediately before the separation roller 322 in the conveyance direction of the document 300,
A document sensor 304 is provided. The document sensor 304 is a photo interrupter type or limit switch type detector, and detects the stack of the documents 300, that is, the presence or absence of a document to be transmitted next. A photo interrupter-type document sensor 320 is also arranged behind the transport roller 306.

As shown in the enlarged view of FIG. 4, the original document sensor 320 is disposed in front of the original reading position P2 by a predetermined distance in the transport direction A1, and the original 300 having a length exceeding the predetermined distance from the reading position P2 is detected. It has a function of detecting whether or not it exists. This detection, when a predetermined time has elapsed from the start of communication,
According to the output of the sensor 320, the trailing edge 330 of the original 300 is
It is performed by identifying whether or not it exists at the position of. When the passage of the trailing edge 330 of the document 300 is detected, the message to be transmitted ends if the document 300 is conveyed by the number of sub-scanning lines corresponding to the predetermined distance from that point onward. The control unit 136 can make the determination.

In this embodiment, the sensor 320 that regulates the document reading position P2 is used to determine the amount of untransmitted information of the document 300.
Other means of determining the amount of untransmitted information in 300 may be utilized.

The device 100 may have a reception function of receiving facsimile data from a line and recording the data as visible information on a recording medium. However, this receiving function is not directly related to the understanding of the present invention, so that it is omitted here and its detailed description is omitted.

A character generation circuit (CG) 126 is connected to the encoder 108 via a picture signal conversion unit 124. The image signal conversion unit 124 is a circuit that converts the character pattern data generated by the character generation circuit 126 into an image signal. When the character data generated in this device is transmitted from the line interface 130, the output of the image signal conversion unit is transferred to the buffer 106 through the encoder 108. The character generation circuit 126 may be a normal character generator that generates character pattern data according to the character data from the system controller 136.

The signal line 102 is also connected to the procedure signal detector 110 and the procedure signal transmitter 112. The procedure signal detection unit 110 has a function of detecting a procedure signal received by the line interface 130 from a partner station in a facsimile transmission control procedure such as a G3 facsimile transmission control procedure according to CCITT recommendation. Under the control of the system control unit 136, the procedure signal sending unit 112 is a functional unit that sends to the line interface 130 a procedure signal to be transmitted from the line interface 130 to the partner station in a facsimile transmission control procedure.

The functions and operations of these parts inside the device are controlled by the system controller.
Controlled by 136. The system controller 136
In this embodiment, a processing system having a processing unit (CPU) 141 such as a microprocessor is advantageously used. As will be described later, the storage device is provided with an operation memory 144 for holding operation information necessary for restarting communication that has been disconnected due to the elapse of the communicable time. The operation memory 144 holds, as such operation information, for example, a set value of the linear density at the time of transmission.

A dial memory 150 is also connected to the system control unit 136. This is a storage device that holds identification information (subscriber number) of the communication partner. A dial sending unit 152 is connected to the dial memory 150, and its output 154 is connected to a line. The dial sending unit 152 is a circuit for sending a called party selection signal to the line in the form of dial pulse or MF signal according to the data held in the dial memory 150.

The system control unit 136 may also include a timer 146. This is a counting function unit that is activated when a call is made to a partner station in a communication start state in the case of an outgoing call and counts the elapsed communication time within a predetermined communicable time T (Fig. 2) assigned to the communication. is there.

An operation unit 140 is connected to the system control unit 136. The operation unit 140 includes a manual operation button for giving an instruction to the apparatus, for example, buttons for start, stop, reset, power on / off, copy instruction, and the like, as well as a called party identification such as a subscriber number of a transmission destination. It is an operation device unit having an operation mechanism such as a key for inputting information, such as a numeric keypad.

In addition to this, the present embodiment has a "re-communication" button 142 which gives an instruction to resume the communication once disconnected by re-calling the same called party and requesting the connection to the switching network. The operation unit 140 may also have a display function for displaying to the user, for example, when the connection is disconnected due to a shortage of remaining communication time when the document 300 to be transmitted remains. . This display may be a visual display or an audio audible display.

By the way, in communication systems where communication time is limited,
The connection may be forcibly disconnected while sending 1 unit of message. In this embodiment, for example, as shown in FIG. 5, when the portion 300a of the length L1 of the original 300 is transmitted and the connection is restored, the portion 300b of the remaining length L2 is retransmitted by the operation unit 140. The button 142 can be operated to send. At that time, the document 300 is conveyed in the reverse direction A2 by a predetermined length L3, and the document information of the tail part 300c of the first half part 300a is transmitted again. The shaded portion 300c in the figure is the portion that is redundantly transmitted by re-communication. In this case, on the receiving side, the last part 30
The 0c and the second half portion 300b may be recorded subsequently to the recording paper on the same page as the first half portion 300a, or may be newly recorded on the recording paper on another page.

In the present embodiment, when transmitting the latter half portion 300b from the transmitting side, prior to that, additional information such as characters and symbols indicating that it is a continuation of the first half portion 300a is created and transmitted as image information. You may comprise. On the receiving side, this is recorded on the recording paper prior to the recording of the second half 300b. Or
A part of the latter half portion 300b is replaced with the additional information and recorded on the recording paper. This will cause the user to
It is possible to identify that the succeeding portion 300b of the first half portion 300a of the is received.

Of course, when the length of the document 300 is too long to be transmitted in the communicable time T, the transmission operation after the communication disconnection described above may be repeated.

Referring to FIG. 2, a call connection flow in which the present apparatus performs typical facsimile transmission of a document of a plurality of pages according to the CCITT recommended G3 facsimile transmission control procedure will be described. In this example, the device functions as the transmitting station TX. RX station
May be the present device or another device.

When performing facsimile communication, first, the ten-key pad of the operation unit 140 is operated to input the called subscriber number. Also, the linear density at the time of transmission is set to, for example, 3.85 lines / mm or 7.7 lines / mm. These set values are input to the system control unit 136, the subscriber number is stored in the dial memory 150, and the line density is stored in the operation memory 144.

The system control unit 136 of the transmitting station TX is the line interface 1
The line is called from 30 and the selection signal is sent to the dial sending unit 152 based on the information stored in the dial memory 150.
Therefore, the procedure signal transmitting unit 112 calls the receiving station RX through the line interface 130. This calling is performed by sending a calling signal in the automatic mode. In response to the calling signal, the receiving station RX returns a CED (called station identification) signal to the transmitting station TX, and subsequently returns a DIS (digital identification) signal. In the manual mode, the transmitting station TX calls by a voice signal, and the receiving station RX responds to this by operating the operation button.

After confirming the CED signal from the receiving station RX, the sender operates the start button of the operation unit 140. System control unit 136 of transmitting station TX
Starts the timer 146 when the partner station is called. As a result, counting of the already communicated time is started. The procedure signal detection unit 110 of the transmission station TX detects the CED and DIS signals, and the system control unit 136 responds to this by the DCS in the same manner as described above.
Send a (digital command) signal. After that, a predetermined modem training pattern signal is received by the receiving station RX according to a normal facsimile transmission control procedure, and training of the modulation / demodulation device of the receiving station RX is performed. When the receiving station RX finishes the training, it returns a CFR (reception preparation confirmation) signal to the transmitting station TX.

In the transmitting station TX, when the procedure signal detection unit 110 detects the CFR signal, the system control unit 136 controls the pulse motor control unit 138 to drive the pulse motor 132 of the reading unit 116 and set in the operation memory 144. The set linear density value is set in the pulse motor control unit 138. As a result, the reading of the image information of the original 300 is started at the linear density. The image information, that is, the message read from the original 300 by the photoelectric conversion element 324 is compression-encoded via the line buffer 118, the encoder 108, the buffer 106, and the modulator 104, assembled into a transmission frame, and modulated. It is transmitted from the line interface 130 to the line.

The receiving station RX receives this signal, demodulates it, deframes it, reproduces the code, and finally outputs it as a hard copy on recording paper from its recording unit.

Generally, at the beginning of reception, sender information and date / time information are recorded. For this, for example, the sender display function described in JP-A-54-106110 is advantageously applied. At that time, the system control unit
136 connects the encoder 108 to the image signal converter 124. As for the data of the transmission source, a necessary message is assembled according to an instruction from the system control unit 136 or the timer 146 of the transmission station TX, is expanded by the character generation circuit 126 as dot pattern data, and is transmitted. At the receiving station RX, this is recorded on the recording paper by the recording unit in the same manner as a normal message.

In this embodiment, the image information message for one unit, that is, one page in this embodiment is transmitted from the transmitting station. When the next transmission original does not exist, the system control unit 136 of the transmission station TX sends an EOP (procedure end) signal in the end processing, and the reception station RX returns an MCF signal in response to this.
When the TX of the transmitting station detects the MCF signal, it returns a DCN (disconnect command) signal to the receiving station RX to restore this connection.

Meanwhile, during that time, the system control unit 136 of the transmitting station TX monitors the count value of the timer 146. When this count value, that is, the already communicated time reaches a predetermined reference value that is slightly shorter than the communicable time T, the system control unit 136 causes the reading unit 116 to display the document 30.
Determine whether 0 remains. At this point, the output from the sensor 320 of the reading unit 116 is transferred to the system control unit 13
It is carried out by taking it in 6 and judging whether or not it indicates the existence of the document 300 at the position P1. The above-mentioned reference value is then set to a length necessary for performing termination processing including transmission of the EOP1 signal described later.

When it is determined that the sensor 320 does not detect the remaining message, that is, the presence of the document 300 having a length equal to or longer than the predetermined length, the system control unit 136 continues the transmission until the end of the message being transmitted at that time. That is, the image information up to the final end 330 of the original 300 is read by the reading unit 116 and transmitted.
When this is completed, the system control unit 136 of the transmitting station TX
Perform normal termination processing. That is, the EOP signal is sent out, and the receiving station RX sends back the MCF signal in response to this. When the TX of the transmitting station detects the MCF signal, it returns a DCN signal to the receiving station RX to restore this connection. These are done within the remaining time.

When it is determined that the sensor 320 detects the remaining message, that is, the presence of the portion of the document 300 having a predetermined length or more,
The system control unit 136 stops the transmission of the message,
Required termination processing such as sending an EOP1 signal different from the EOP signal in the normal termination processing is performed, and finally the call connection is restored. At this time, the system control unit 136 controls the pulse motor control unit 138 to stop the pulse motor 132,
As a result, the original 300 remains in the reading unit 116 as it is, with the latter half 300b left.

Therefore, the sender operates the resend button 142 of the operation unit 140. In response to this, the system control unit 136 controls the recalling, transfers the selected number of the called party stored in the dial memory 150 to the dial sending unit 152, and executes the above-mentioned calling operation again. During the transmission of this selection signal, the system control unit 136 instructs the pulse motor control unit 138 to rotate the pulse motor 132 in the reverse direction and drive the transport roller 306 in the reverse rotation direction. As a result, the document 300 is conveyed in the direction of arrow A2 by a predetermined length L3. Further, the linear density setting value of the operation memory 144 is set in the pulse motor control unit 138. The following operation proceeds in the same procedure as the setting of the facsimile call connection described above.

When the reconnection is set in the communication system and the modem training is completed in this way, as shown in FIG. 2, the image information of the tail portion 300c of the first half portion 300a is transmitted at the beginning of the message signal. Note that the system control unit 136 controls the image signal conversion unit 124 and the character generator 126 in the same manner as in the case of transmitting the source information, and the above-mentioned additional information, that is, the message of the latter half portion 300b of the original 300 from this is added. May be sent. This is generated as character string data by the character generator 126, converted into an image information pattern by the image signal conversion unit 124, and transmitted. This is the receiving station
Received by RX and recorded on recording paper as normal image information. The document 300 may be conveyed in the reverse direction while the connection setting to the partner station is completed in the communication system and the transmission control procedure is being executed. In any case, the original 300 is conveyed in the reverse direction A2 under the control of the system controller 136 between the operation of the re-send button 142 and the start of message transmission.

As can be seen from the above, in the first connection setting, the operator operates the key to input the called subscriber number, but in the subsequent reconnection, only the resend button 142 is operated.
Therefore, the operation is very simple. Of course, the operation unit 140
Even if a resend signal button is not provided on the same recipient, by combining the operations of buttons such as a numeric keypad, the same number of operations can be performed with a smaller number of operations than the initial connection setting operation and without resetting the original 300 on the reading unit 116. Alternatively, the following part 300b of the manuscript 300 and the part 300c immediately before it may be transmitted.

By the way, in the conventional method, when the transmission of the original is started during the transmission of the available time during the transmission of the original and the next original is sent again by re-communication, the receiver receives the information between the reception of the first half and the reception of the latter half. There remains anxiety that there was a lack of. Further, since the document reading unit generally uses a pulse motor, when the transmission is stopped, the document may slightly move due to an error in the pulse motor mechanism system, vibration during the period, or the like. Due to such a cause, in the conventional apparatus, there is a risk that image information for one line or several lines may be lost.

In this embodiment, as a countermeasure against this, at the time of re-communication,
Prior to the transmission of the next document portion, the end of the document portion previously transmitted is duplicated and retransmitted. Therefore, in the embodiment of the present invention, the length of the overlapping portion 300c to be retransmitted is
It can be seen that L3 should be set to include these few lines. As a result, the receiver can recognize the overlapped portion and eliminate the inconvenience caused by the mechanical system of the reading unit.

In the illustrated embodiment, the present invention has been described with respect to the standard transmission procedure of the CCITT recommendation G3 facsimile, but the present invention is effectively applied to the facsimile according to other transmission procedures such as the same G2 facsimile and other data transmission. It Further, the present invention is not limited to communication restoration due to the passage of communication available time,
It is effectively applied to any communication system in which communication may be disconnected while untransmitted information remains.

Further, in the above-described embodiment, the image information of the original 300 is directly read and transmitted from the reading unit 118, but the present invention is also applicable to a system in which a predetermined unit of message is transmitted from the information held in the memory. Is effectively applied. In that case, the remaining information can be determined by managing the address for reading the information from the memory. That is, the presence or absence of residual information is determined by comparing the final address in which the information to be transmitted is stored with the address of the information currently being transmitted. The head address of this residual information in the memory may be retained, and the transmission of information may be started from the storage position of the address traced back by a predetermined value from the address when the next communication is restarted.

Effect According to the present invention, in the data communication method in which the communication time length is restricted, if untransmitted information remains in the transmitting station when disconnected during communication, the previous call is transmitted in the next recall connection. This can be sent in duplicate with the information given. At that time, the condition set in the previous communication connection is held and used in the next retransmission. This simplifies the retransmission operation, and information can be reliably transmitted.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a data communication apparatus according to the present invention, and FIG. 2 is a CCITT recommendation G in the embodiment shown in FIG.
3 Flowchart showing an example of a call connection flow for performing facsimile transmission according to the facsimile transmission control procedure, FIG. 3 is an explanatory diagram showing a structural example of the mechanical portion of the reading unit in the embodiment shown in FIG. 1, and FIG. , An explanatory view showing an enlarged part of FIG. Fifth
The figure is an explanatory view showing an example of a transmission document. Explanation of symbols of main parts 112 …… Procedure Signal sending unit 116 …… Reading unit 126 …… Character generation circuit 132 …… Pulse motor 136 …… System control unit 138 …… Pulse motor control unit 140 …… Operating unit 141 …… CPU 142 …… Re-communication button 144 …… Operation memory 146 …… Timer 150 …… Dial memory 152 …… Dial sending part 304,320 …… Document sensor 306 …… Conveying roller

Claims (1)

[Claims] 1. In a data communication device that cannot communicate for more than the communicable time, a time limiter that counts an elapsed time from the start of communication and monitors a predetermined time limit, and a detector that detects remaining untransmitted information. When the time limit means reaches the predetermined time limit, the time limit means has a determination means for determining whether to continue or end the communication based on the detection result of the detection means, and it is determined that the communication is to be ended. In this case, the data communication device is characterized in that a predetermined communication termination procedure is performed to disconnect the communication line, and when the communication is resumed, the untransmitted information is transmitted.