JP2763527B2 - Facsimile machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an error retransmission request issued from a receiving side.
Related to facsimile machines that perform error retransmission
It is. [Prior Art] Conventionally known facsimile machines use error recovery.
Image data read by the reading means for
Stored in memory for error resend request
Read the frame from the memory and retransmitted it.
However, an error retransmission request is made for any frame.
Is unknown in advance, so be prepared for error retransmission.
Stores all image data read by the reading means in the memory
And that has been done to send. However, if the original size is large or the original image
The image data of all originals in memory at once.
Since image data cannot be stored, the image data
Read the data, store the data in memory and send it,
The image data stored and sent to memory
After confirming that the transmission request signal does not come,
A, scan the rest of the original, and scan it again.
The image data was stored again in the memory and transmitted. In this case, the image data read and transmitted first
Check that no error retransmission request signal is received
The image data of the remaining original that was newly read is
Before starting, the memory is cleared once and the remaining
Because it took time to read the original,
If no error retransmission request signal is received for the captured image data
In any case, image data exceeding the memory capacity
There is a disadvantage that transmission cannot be performed continuously. Conventionally, continuous image data transmission is possible,
As a facsimile machine that performs retransmission, error retransmission
Some facsimile machines have a dedicated memory.
This facsimile apparatus reads image data of a scanned document.
A memo dedicated to error retransmission at the same time that the image data is sent.
Remember. Then, an error retransmission request signal is
If it is received, the image data is
And resend. However, this dedicated memory has 1
Used once if no error occurs during communication
It was a memory with no low usage rate. Also, with conventional facsimile machines, the read image
Different processing speed when transmitting data continuously
A few lines to adjust the read and send processing of
Transmission buffer memo with memory capacity for image data
I have And using this buffer memory
Read processing performed at different processing speeds.
While adjusting the processing and transmission processing,
Sending. Therefore, a facsimile apparatus that performs error retransmission is provided.
In this case, the memory dedicated to error retransmission and the
Memory is provided separately, and the configuration of the
And the memory is being used effectively
There is no problem. [Purpose] The present invention relates to reading processing and sending processing at different processing speeds.
Buffer memory provided for adjusting communication processing
Is also used as a memory for error retransmission, thereby
The purpose is to simplify the configuration. [Means for Achieving the Object] In order to achieve the object, the facsimile machine according to the present invention is used.
The millimeter device includes reading means for reading a document image, and image data.
Transmitting means for transmitting an image, and an image read by the reading means.
Once the data is stored, the stored image data is
Reading the original image by the reading means
And the image data transmission process by the transmission unit is asynchronous
Buffer memory means for enabling
An error retransmission request signal for the decoded image data
Receiving means, and image data read by the reading means
Processing for storing in the buffer memory means,
The image data is read out from the memory means and transmitted by the transmitting means.
Transmission process to be transmitted by the error retransmission request signal.
The read image data from the buffer memory means again
Performing a retransmission process for causing the transmission means to retransmit,
Control means for asynchronously executing the storing process and the transmitting process;
And the memory capacity of the buffer memory means is controlled as described above.
Larger than the memory capacity required for error retransmission control by
The control means, when executing the storing process,
Sent by the sending means and retained for resending
The image data that no longer needs to be stored
Image data newly read in the area of the buffer memory means
Is stored. Embodiment First, an outline of a facsimile apparatus according to an embodiment of the present invention will be described.
The point is important. When transmitting image information (transmitting side), the encoded
An in-number is assigned to each line and transmitted together with image information.
You. Then, from the code corresponding to a certain line number,
The subsequent data can be retransmitted. On the receiver side, the line number is
Check for errors and thereby determine if there is a reception error.
You. When the data is received correctly,
Decryption is performed by removing the number. On the other hand,
When the occurrence of a communication error is recognized, the receiving device
A signal is transmitted to interrupt the transmission of the image information of the transmitting apparatus.
After that, the receiving device sets the retransmission request start line number.
Notify the sending device. This allows the transmitting device
Resumes transmission from the retransmission request start line number
You. The line number is a signal indicating the end of the code of one line.
Signal, for example, “EOL” (End of Line; based on CCITT Recommendation T4)
Modified Huffman coding or Modified
Used when performing Fed-Read coding etc.
After). This allows the receiving device to
Enables the identification of the image information and the line number. Hereinafter, this embodiment will be described in detail with reference to the drawings. In the transmitting facsimile machine, the encoded
Data is stored in FIFO (First-In First-Out) memory
It is. Fig. 1 shows the relationship between FIFO memory and various pointers.
You. Assume that the FIFO memory capacity is between 8400H and AFFFH.
(Corresponding to the “memory capacity” of the present invention). Here, the start address of the FIFO memory of the transmitting device is TF
IFS (TRN FIFO START; 8400H in this embodiment)
The final address in the FIFO memory of the receiving device is TFIFE (T
RN FIFO END; referred to as AFFFH in this embodiment. In the transmitting device, reading is performed by reading means (not shown).
After the data is encoded, it is
Stored in FIFO memory, but control FIFO memory
Use the pointer to control Used for this
This pointer is called TMHPTR (TRN MH POINTER). Also,
The data stored in the transmitter's FIFO memory is
, And sequentially transmit to the line.
You need a pointer to control the memory of the FO.
The pointer used for this is TMDPTR (TRN MODEM POIN
TER). Regarding the management of the FIFO memory included in the transmitting device,
This is described below. Encoder pointer TMHPTR, FIFO memo
In the re-space, the encoded data up to
Indicates whether it has been torred. Meanwhile, the modem pointer TMDP
TR is where data is stored in the FIFO memory space.
Indicates whether the signal has been modulated and transmitted to the line. The encoder starts from the TFIFS address at the beginning of the memory.
Stores the encrypted data, and stores the final address of memory in TFIFE
When data encoded up to the address is stored, the next code
Stores the converted data at the TFIFS address at the top of the memory
I do. At this time, 1 is set to the flag of REVRS (reverse).
Set the encoded data to the modem
The encoder pointer TMHPTR is stored up to the last address.
Informs you that you have returned to the top of the FIFO. On the other hand, as a process on the modem side, the TF
Read the encoded data from the IFS address sequentially and change
After adjusting, it is sent to the line. And the end of the memory
Reads data stored at address TFIFE
After modulating and transmitting to the line, the start address of the memory is
Reads data stored at TFIFS address and modulates
And send it out to the line. At this time, set 0 to the flag called REVRS (reverse).
For the encoding side, the last address of the FIFO is
Data modulation and transmission to the line are
That the pointer TMDPTR has returned to the beginning of the FIFO.
Let The main functions of FIFO management in the transmitting device are as follows
It is. The encoder pointer TMHPTR goes around the FIFO memory
Avoid getting too close to the modem pointer TMDPTR
(Retransmission is performed when a reception error occurs on the receiving side.
Data for resending data in the FIFO memory
Me). Next, the FIFO management will be described. In FIG.
Are sent for 3 seconds at each transmission speed
The number of bits and the number of bytes are shown. That is, round trip
In order to be able to retransmit up to a 3 second delay
Is the encoder pointer TMHPTR is the modem pointer TM
DPTR must be at least 3600 bytes apart. FIG. 3 shows the relationship between the FIFO memory and various pointers. Book
In the embodiment, the encoder pointer TMHPTR is incremented.
When comparing with the modem pointer TMDPTR,
The encoder pointer TMHPTR becomes the modem pointer TMDPTR.
4096 bytes (error retransmission control by control means of the present invention)
Memory capacity required for control. " ) Or more
To control. Next, according to the present invention, "the image data read by the reading means"
When inputting data to the memory means,
A new address is sent to the address where the transmitted image data was stored.
The storage of the read image data is
Stores the latest transmitted image data among image data
Permission except for a certain amount of addresses
explain. Hereinafter, a specific example of the control will be described. When the encoder pointer TMHPTR is incremented
Then, the REVRS (reverse) flag is checked. No.
(1) in Fig. 3 is when the REVRS (reverse) flag is 0.
FIG. At this time, the last address of the memory TFIFE
− (Encoder pointer TMHPTR)｝ + ｛(modem pointer
Inter-TMDPTR)-Start address of memory TFIFS｝ <4096 bytes
Judge whether or not the
Interrupts the code and enters the wait state. Also, the above
When the condition is not satisfied, that is, ｛TFIFE- (en
Coder pointer TMHPTR) + + (Modem pointer TM
DPTR)-Encodes when TFIFS｝ ≥4096 bytes
Then, the encoded data is stored in the FIFO memory. On the other hand, (2) of FIG. 3 shows REVRS (reverse)
FIG. 5 is a diagram illustrating a case where a flag is 1. (Point of modem
TMDPTR)-(encoder pointer TMHPTR) <4096 bytes
Judgment whether or not the above conditions are met and the above conditions are met
Suspends encoding and enters a wait state. above
If the condition is not met,
TMDPTR)-(encoder pointer TMHPTR) ≥ 4096 bytes
At the time of writing, encoding is performed, and the encoded data is
Store in FO memory. The transmitting side device reads the original by reading means (not shown).
Reads the information, encodes the data with an encoder,
A modem modulates the encoded data and sends it to the line.
Is out. At this time, the NACK signal (in this embodiment, PI
Monitoring the S signal). And it detects the NACK signal
If not, image information is transmitted and a NACK signal is detected.
In this case, transmission of image information is interrupted. And a 300b / s signal
Head for reception. In this 300b / s, the line to start retransmission
Number (lower 9 digits) is stored. When the transmitting device detects the retransmission start line number,
In the encoder pointer TMHPTR in the transmitting device
Address, modem pointer TMDPTR in the sending device
Address, REVRS (reverse) flag, retransmission start address
Check the status of each item, and perform various controls based on the results.
U. As examples of this control, there are three cases described below.
Conceivable. The first case is when the REVRS flag is 0 and the sender
The encoder pointer TMHPTR in the device is
Sent when the modem pointer TMDPTR is larger than
The modem pointer TMDPTR of the local device is
This is the case when it is larger. FIG. 4 (1) to (3) show that the retransmission start address is recognized.
Then, three cases of performing retransmission are shown. Stated here
The first solid case is shown in FIG. 4 (1). This
In the case of, the modem pointer TMDP in the transmitting device
Set the retransmission start address in TR and the line number
To resend. The second case is illustrated in FIG. 4 (2). sand
That is, if the REVRS (reverse) flag is 1 and the transmitting side
When the modem pointer TMDPTR in the device is
This is a case where the pointer is larger than the encoder pointer TMHPTR.
In this case, the pointer TM of the modem in the transmitting device
Set the retransmission start address in DPTR, and
And resend the message. Here, the encoding in the transmitting device is performed.
If the pointer TMHPTR of the
In this case, it is determined that an error has occurred, and image information is transmitted.
Without sending DCN signal etc. (by 300b / s)
And release the line. The third case is illustrated in FIG. 4 (3). sand
That is, if the REVRS (reverse) flag is 0 and the transmitting side
The encoder pointer TMHPTR in the device is
Retransmit when the modem pointer TMDPTR is larger than
The start address pointer is
This is the case when the pointer is larger than TMDPTR. In this case,
Start retransmission to the modem pointer TMDPTR in the transmitting device
Set the address and resend from that line number.
U. Here, the pointer of the encoder in the transmitting device
If TMHPTR is greater than the retransmission start address, an error is determined.
Without transmitting image information, such as DCN signals
(300b / s) and release the line. FIG. 5 is a block diagram showing the configuration of the transmission side of the facsimile apparatus.
It is a lock figure. In FIG. 5, reference numeral 2 denotes a network control device for holding a loop.
NCU (Network Control Unit)
Connect to the terminal of the line and use it for communication
Controls connection of talk switching network or data communication
Switch to the road. 2a is a telephone line. Reference numeral 4 denotes a hive that separates a transmission system signal and a reception system signal.
It is a lid circuit. The transmission signal of the signal line 28a is transmitted through the signal line 2b.
Via the network controller 2 to the telephone line 2a.
You. Also, the message sent from the other party's facsimile
The signal is output to the signal line 4a after passing through the network control device 2.
You. 6 is a retransmission request signal transmitted from the receiver (this embodiment)
Uses a PIS signal).
You. That is, the signal on the signal line 4a is introduced, and the retransmission request signal
(In this embodiment, the PIS signal)
The signal of the signal level "1" is output to the signal line 6a. on the other hand,
The signal of the signal line 4a is introduced, and a retransmission request signal (in this embodiment,
When no PIS signal is detected, the signal line 6a
A signal of signal level "0" is output. 8 is transmitted following the retransmission request signal from the receiving device.
300b / s in which the retransmission start line number to be stored is stored
Signals (NSF signals are used in this embodiment) and
Disconnect command (DC
N) A circuit that receives a signal (300 b / s signal). this
When the binary signal receiving circuit 8 detects the NSF signal,
Generates a pulse on signal line 8a and retransmits it on signal line 8b
Output the starting line number. Also, this binary
When the signal receiving circuit 8 detects the DCN signal, it connects to the signal line 8c.
Generate a pulse. Reference numeral 10 denotes a reading device, which is one line in the main scanning line direction from the transmission original.
Reads the image signal for IN and displays the binary value of white or black.
A signal sequence (corresponding to the "reading means" of the present invention)
). This reading device 10 captures an image of a CCD (charge coupled device) or the like.
It is composed of an element and an optical system. Reading one line of image signal
When there is a request, the image signal of one line is read and binarized.
The output data is output to the signal line 10a. 14 is the line inserted after the line end code (EOL)
It is a counter that counts numbers. Signal line 30c
When a pulse is generated, the line number is set to 0.
You. Each time a pulse is generated on the signal line 30d,
Increment the value of the number. That is, the line
When a pulse is generated in the signal 30d while the number is 0
The line number is 1. The same applies hereinafter. Ma
The 2-byte data indicating the line number is a signal line
Output to 14a. 16 is the binarization of one line output to the signal line 30e
The encoded data is input and encoded (in this embodiment, the
Decoded Huffman coding) data to signal line 16c
Circuit. One line of binary data
Is input, and the number of bits when encoding becomes 8
In other words, 1 byte of encoded data is complete
At this time, a pulse is generated on the signal line 16a. Meanwhile, one line
When the encoding of all has been completed, (end)
Generate a pulse. When encoding of one line is completed,
If the last data is less than 8 bits, the remaining data
Data is set to 0, and the data
Work. 18 reads the line data and stores the encoded data.
This is the FIFO memory used to perform the
Means ". ). On the other hand, the modem side is not stored in this FIFO memory.
The data is read out, modulated and transmitted to the line. Signal line
From 30f, encoded by three signal lines of signal line 30h
Write data to FIFO memory. Connect the signal line 30f
G) When a pulse is generated, it is output to signal line 30g.
Address, the byte data output on signal line 30h
Store the data. Also, the signal line 30i, the signal line 30j, and the signal line 18a
Are stored in the FIFO memory by the three signal lines
Read data. (Read) pulse is generated on signal line 30i
Address, the data of the address output on signal line 30j
Is output to the signal line 18a. In this embodiment, the FIFO
The memory has from 8400H to AFFFH. 20 is a retransmission start address storage memory, which
When a receiving error occurs on the receiving side,
Resend from the line number where the error occurred. Submit
Retransmit from a certain line number in the side device
If the line number data is
It is necessary to know if it is stored from the ground,
Store the data in this memory. Signal line 30k, signal line 30l,
Using the signal line 30m, "The data of a certain line number is F
From which address in IFO memory is stored?
The information is written in the memory 20. (Light) pass to signal line 30m
When an error occurs, the address output on signal line 30k is
The byte data of the signal line 30l is stored. Also, signal line 3
0k, signal line 30n, signal line 20a
From which address in the FIFO memory is stored
Is read from the memory 20. Then, it is assumed that a (read) pulse has occurred on the signal line 30n.
The data at the address output on signal line 30k
Output to 0a. 24 is based on the well-known CCITT recommendation V27ter (differential phase modulation).
(The "transmitting means" of the present invention)
Is equivalent to ). The modulator 24 receives the signal on the signal line 22b.
To perform modulation and output the modulated data to the signal line 24a.
You. 26 is a signal line 26a when a pulse is generated on the signal line 30p.
Is a circuit for sending a DCN signal (300 b / s signal). 28 inputs the signal of the signal line 24a and the signal of the signal line 26a,
This is an addition circuit that outputs the result of the addition to the signal line 28a. Reference numeral 30 denotes a control circuit that performs the following control. However, sign
Processing is performed according to the main routine, and signal transmission is performed
Processing is performed by a tapout routine. The encoding by the control circuit 30, that is, the main routine
FIG. 6 shows the control process in the operation. Ma
The modem pointer TMDPTR and encoder pointer
Data in the FIFO memory that stores the encoded data.
It is set to the start address (step S100). And
Reading of image information of one main scanning line is completed.
Whether the line buffer is full
(Step S102). Reading of the image information of the main scanning line in one line is completed.
(Ie the line buffer is full)
And proceeds to step S104. And one line of data
Is read (step S104). After data is read from each buffer, it is encoded and
Write the coded data to the FIFO memory (step
S106). The main controls during encoding are listed below.
You. (1) Write the encoded data to the FIFO memory. (2) Line end code (EOL signal) and line number
Is written to the FIFO memory. (3) When a receiving error occurs in the receiving device,
In the transmitting device, the error line number
Retransmit data (corresponding to “retransmission control means” of the present invention)
You. ). The following control is performed to enable this retransmission.
U. In other words, the encoder pointer TMHPTR is incremented.
The encoder pointer TMHPTR
Go around the pointer TMDPTR around the FIFO memory and get too close
Control so that it does not break. Specifically, the encoder
TMHPTR to the modem pointer TMDPTR
When approaching, the coding is interrupted and a wait state is set.
When waiting, the PIS signal is detected.
Is checked, and if a PIS signal is detected, N
Performs SF signal reception. And resend the modem pointer
Set to the start address and resend from that data
U. When performing this retransmission, training is performed again. This
This is the same as the control from step S108 to step S112 described later.
Is the same. (4) When resending from a certain line number,
From which address in the FIFO memory the in-number data is stored
Need to be aware of Start resending this information
Store in the address storage memory. When encoding of a certain line is completed,
Determine whether or not the request signal, that is, the PIS signal is detected
(Step S108). Retransmission request signal, that is, PIS signal
Stops the transmission of image information and the reception of NSF signals.
Is performed (step S110). And the modem pointer TM
The retransmission start address of DPTR (this information is included in the NSF signal)
And resend from that data
(Step S112). Next, it is determined whether encoding of one document has been completed.
(Step S114). Encoding of one document has not yet been completed
If not, the process returns to step S102. In addition, one original
If the encoding of the manuscript has been completed, the process proceeds to step S116. When encoding of one document is completed, step S118 is performed.
And returns the control return signal RTC (Return To Control) to the FIFO
Write to memory. On the other hand, the transmission process (that is, the interrupt process) consists of (a) the data stored in the modem pointer TMDPTR.
And (b) sequentially increment the modem pointer TMDPTR.
That is the main content. Steps S328 to S354 shown in FIG. 7
Is the encoder pointer TMHPTR increment processing
Is shown. Here, in step S330, the encoder
Increment TMHPTR. And the encoder
Is incremented, the process proceeds to step S334.
Proceed to. In steps S334 to S338, the
The pointer TMHPTR of the
Control so that it is not too close to the DPTR.
"The image data read by the reading means is stored in the memory
An image that has been sent by the sending means when inputting to the means
Image newly read to the address where data was stored
Storing the data in the transmitted image data
A certain amount of address storing the latest transmitted image data
Permitted except for the address). ). Sand
The encoder pointer TMHPTR is replaced by the modem pointer.
If it is 4096 or more away from the TMDPTR, return.
At this time, the encoder pointer TMHPTR
Check in step S350 whether the end has been reached,
If the end of the FIFO memory has been reached,
Set 8400H (first address of FIFO memory) to pointer TMHPTR.
And set the REVRS flag to 1. Encoder pointer TMHPTR is modem pointer TMDP
If the TR is not more than 4096 apart, stop coding and
Enter the wait state. While waiting, retransmission request
Determine if a signal (ie PIS signal) has been detected
(Step S340). And when the PIS signal is detected,
Suspends transmission (step S342) and stops receiving the NSF signal.
Perform (step S344). Then, the retransmission start line number
Key (step S346), and the modem pointer TMHPTR
To the resend address. In this embodiment, when a PIS signal is received, NSF
Going to receive signal, but receive DCN signal at this time
Then, the line is disconnected and the error processing ends. The flowchart shown in FIG.
Details of the transmission process (ie, the interrupt process)
A detailed control process will be described. In this embodiment, the modulator 24 has one
This interrupt processing is performed every time data transmission is completed.
Be executed. The main control here is the data stored in the FIFO memory.
Are sequentially read (steps S370 to S376).
And When the modem pointer reaches the end of the FIFO memory
Sets the modem pointer TMDPTR to the start address of the FIFO memory.
8400H and the REVRS flag to 0
Steps S398, S400). Also, the encoding is completed (MHEND = 1) and the modem
Sent all the encoded data (TMHPTR = TMDPTR)
At this time (step S364), TRNEND is set to 1 (step S364).
Step S366), the transmission of the encoded data has all ended.
To the main processing routine (encoding processing routine)
Inform. [Effects] As described above, according to the present invention, reading is performed by the reading unit.
Once the captured image data is stored, the stored image data
Is supplied to the transmitting unit, and the reading process of the original image is performed by the reading unit.
The image data transmission process by the transmission means asynchronously
It has buffer memory means to make it executable
Buffering of image data read through the storing process and the transmitting process
Storage processing in the buffer memory means and image data from the buffer memory means.
Asynchronous execution of transmission process for reading and transmitting image data
Buffer the image data specified by the error retransmission request signal.
Read out again from the buffer memory means and resend
The memory capacity of the means is equal to the memory capacity required for error retransmission control.
When executing the storage process, it has been sent and
Image data that no longer needs to be retained for retransmission
Newly read in the area of the buffer memory means that was stored
Buffer memory for transmission
And memory for error retransmission, and memory dedicated to error retransmission
And the configuration of the device can be simplified.
The storage of the image data in the buffer memory means and the buffer
Transmission of image data read from the memory means
Error retransmission control of the memory capacity of the buffer memory means
Sent and resent
Image data that no longer needs to be stored for
Newly read in the area of the buffer memory
By storing image data, continuous image transmission can be performed.
And keep it for retransmission
Prevent inconvenience of losing necessary image data
Wear.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (1) and 1 (2) are diagrams for explaining the relationship between a FIFO memory and various pointers, and FIG. 2 is the number of bits transmitted in 3 seconds at each transmission speed. FIGS. 3 (1) and 3 (2) show the relationship between the FIFO memory and various pointers, and FIGS. 4 (1) to 4 (3) show the retransmission start address. FIG. 5 is a block diagram showing an embodiment of a transmitting side in a facsimile apparatus to which the present invention is applied, and FIG. 6 is an encoding process of the control circuit 30 shown in FIG. 7 is a flowchart showing the encoding process (ie, main process) of the control circuit 30 shown in FIG. 5, and FIG. 8 is controlled by the control circuit 30 shown in FIG. The procedure for transmitting encoded data (ie, It is a flowchart which shows a (rupture process). 2 ... NCU, 4 ... Hybrid circuit, 6 ... Retransmission request signal detection circuit, 8 ... Binary signal receiving circuit, 10 ... Reader, 14 ... Line number counter circuit, 16 ... Coding circuit, 18 FIFO memory, 20 retransmission start address storage memory, 24 modulator, 26 DCN signal transmission circuit, 28 addition circuit, 30 control circuit.

Claims (1)

(57) [Claims] Reading means for reading a document image; transmitting means for transmitting image data; temporarily storing the image data read by the reading means; supplying the stored image data to the transmitting means; Reading processing, buffer memory means for enabling asynchronous execution of image data transmission processing by the transmission means, reception means for receiving an error retransmission request signal for the transmitted image data, and reading by the reading means Storing the received image data in the buffer memory, transmitting the image data from the buffer memory and transmitting the image data by the transmitting unit, and reading out the image data indicated by the error retransmission request signal again from the memory unit. Executing retransmission processing for causing the transmission means to retransmit, and asynchronously executing the storage processing and the transmission processing; Control means, wherein the memory capacity of the buffer memory means is larger than the memory capacity required for error retransmission control by the control means, and the control means has already transmitted by the transmission means when executing the storage processing. A facsimile apparatus wherein newly read image data is stored in an area of the buffer memory means in which image data no longer required to be held for retransmission is stored.