JPH0515342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a facsimile device, and particularly to a plain paper recording type facsimile device using cut paper.

(b) Prior Art Recently, plain paper recording type facsimile machines have been put into practical use that incorporate electrophotographic PPC (plain paper copier) technology in the printing section for the purpose of high-speed, high-definition recording. Such a facsimile device is disclosed, for example, in the article ``Ultrahigh-speed facsimile device'' on pages 197 to 206 of Research and Practical Application Report of the Institute of Telecommunications, Vol. 33, No. 11 (1984).

By the way, such a facsimile device has a recording speed of 1 ms/line or more, and therefore there is a large difference between the signal transmission speed and the recording speed, so it is not possible to record while receiving, so it is difficult to reproduce one page. After storing an image signal (a signal obtained by decoding an encoded signal into a code format necessary for recording) in memory, recording must be started. Therefore, such a facsimile apparatus requires a page memory with a capacity capable of storing a reproduced image signal equivalent to at least one page of a document. Also,
In the case of PPC technology, the recording paper is cut to a predetermined size, so the documents to be sent and received must be of a predetermined size.

If the document exceeds the specified size and is a so-called "long document," the page memory may overflow and the image may not be received correctly, or the document to be sent may be divided into multiple sheets during recording even though it is one sheet. There are shortcomings that must be recorded. The problem of overflow of the page memory on the receiving side can be solved by sending the long document in multiple batches on the sending side, but this is only applicable to communication between facsimiles of the same type and is not common. Furthermore, as a countermeasure against page memory overflow, simply increasing the memory capacity is not a good idea because it increases cost and increases the size of the device. Therefore, a method can be considered in which the encoded image signal, that is, the coded signal (hereinafter referred to as the coded image signal) is stored in the memory as it is. According to this method, since the coded image signal is data compressed (bandwidth compression) to a fraction of the original image signal, the amount of documents that can be stored at one time increases in proportion to the compression ratio. It is valid. This method therefore avoids memory overflow when receiving long documents.

However, this method causes the following inconvenience when receiving a document within a predetermined size. That is,
According to the current facsimile communication control procedure, the length of the document cannot be known on the receiving side except when the sender and receiver communicate by telephone, and the length is known only after reception is completed. Therefore, on the receiving side, the code image signal must be stored at all times in preparation for a long document that may arrive at an unknown time. As a result, the period from the end of receiving a document within a predetermined size to the end of printing includes decoding processing time (a time comparable to the time required for communication), making the processing time longer than in conventional facsimile. This can be viewed as a reduction in the throughput of the device, as the time required to perform one task increases.

In view of the above-mentioned difficulties, the present applicant has proposed that a plain paper recording type facsimile machine can receive long originals without the problem of overflow, while also reducing processing capacity when receiving originals within a predetermined size. He had previously proposed a facsimile device that did not cause degradation (details can be found in Japanese Patent Application No. 59-242692).

In this method, at the time of reception, the decoded reproduced image signal is stored in the first storage means, and in parallel, the received encoded signal is stored in the second storage means, and after the reception is completed, the reproduced image signal is stored in the first storage means. There is no overflow of the storage means. That is, if the original is within a predetermined size, recording is immediately started. If there is an overflow, the following processing is performed. First, the first
When the storage means overflows, the decoding operation and writing to the first storage means are stopped, and after the reception is completed, recording is immediately started based on the decoding signal in the first storage means, and one page worth of data is recorded. When recording is finished,
Subsequently, the encoded signal corresponding to the remaining portion in the second storage means is decoded and transferred to the first storage means, and when the first storage means becomes full, decoding is stopped and recording begins, and recording ends. At the same time, decoding is restarted, and this operation is repeated until recording for one long document is completed.

(C) Problems to be Solved by the Invention In the above-described method, documents within a predetermined size can be processed quickly, and even long documents can be received without being missing.

However, the processing time for a long document is very short, because after the reception is completed, the process moves to the decoding process for the part that cannot be stored in the first storage means, so the processing time from the end of reception to the end of all recording is very short. processing capacity is reduced.

The main object of the present invention is to provide a facsimile device that does not cause a decrease in processing capacity even when receiving documents within a predetermined size, and can shorten the processing time when receiving long documents. be.

(d) Means for solving the problem The facsimile device of the present invention includes a decoding means,
A first storage means for storing a decoded signal, a recording speed, a second storage means for storing a received encoded signal, an overflow detection means, and a transfer means, the overflow detection means In response to the output of
At the same time, stopping the decoding operation of the decoding means,
Stopping the writing in the first storage means, and recording all the decoded signals stored in the first storage means by the recording means, and immediately after the recording is finished, by the transfer means, The encoded signal stored in the second storage means is transferred to the decoding means, and the decoding operation of the decoding means and writing to the first storage means are restarted.

(E) Effects The present invention can speed up the decoding process even when the document is of a predetermined size. Furthermore, if the document is long, that is, when the overflow detection means detects an overflow in the first storage means, the decoded signal stored in the first storage means is recorded, and immediately after recording, the decoded signal is stored in the second storage means. Transferring the encoded signal stored in the storage means to the decoding means,
The decoding operation and writing to the first storage means are restarted, and decoding and recording are performed even while the document is being received, thereby shortening the reception processing time.

(F) Embodiment Fig. 1 is a block diagram of a facsimile device according to an embodiment of the present invention, Fig. 2 is a flow diagram for explaining the operation of the main controller, and Fig. 3 is a flow diagram for explaining the operation of the sub-controller. FIG. FIG. 4 is a timing diagram showing the transfer state of the code picture signal at each stage of the reception state.
is the transfer timing of the code picture signal at the time of reception before recording the first page, FIG. 4b is the transfer timing of the code picture signal at the time of reception after recording the first page,
FIG. 4c shows the transfer timing of the code picture signal at the time of reception while the reproduced picture signal stored in the page memory is being recorded.

In FIG. 1, a facsimile device 10 includes a system control section 12. As shown in FIG. System control unit 12
is composed of a microcomputer, and its functions include a main controller 12a, a subcontroller 12b, and an internal memory 12c.
The main controller 12a executes operations shown in FIG. 2, which will be described later. Sub controller 1
2b executes the operation shown in FIG. 3, which will be described later. Internal memory 12c includes an area for storing data necessary for reception processing and a flag area for storing various operating states.

The modem 14 takes in the band-compressed encoded signal transmitted via the network control circuit/line, performs processing necessary for data transmission such as error control, and then provides it to the system control unit 12.

A page memory 16 that functions as a first storage means is connected to the system control unit 12, and this page memory 16 stores a reproduced image signal obtained by decoding a code image signal (a signal decoded into a code format necessary for recording). remember. And this page memory 16
includes a storage area for a predetermined number of pages (for example, one page of a manuscript). A code memory 18 is also connected to the system control unit 12 and serves as a second storage means. It also has a capacity that can store code image signals for a much larger number of pages.
The physical configuration of code memory 16 and code memory 18 is, for example,
In the IC memory, the code memory 18 is composed of a magnetic disk memory. Further, part of the page memory 16 may be allocated to the code memory.

The buffer memory circuit 20 is connected to the system control unit 12
and is inserted between the code memory 18 and a sequential code decoding circuit 22 that decodes the code image signal line by line. This buffer memory circuit 20 includes a first buffer memory 20a, a second buffer memory 20a, and a second buffer memory 20a.
buffer memory 20b and a third buffer memory 20c. Buffer memory 20a and 20
B stores the received code image signals alternately until each buffer memory is full, and while one buffer memory stores the received code image signal and is being decoded, the other buffer memory The contents of are transferred to the code memory 18 by direct memory access (hereinafter referred to as DMA). That is, the buffer memories 20a and 20b are divided into decoding and transfer purposes, and the roles are alternately assigned to prevent a decrease in decoding speed.
Further, the buffer memory 20c is used as a buffer memory for decoding source when the operation mode is set to decode the code image signal stored in the code memory 18, that is, when receiving a long document and after recording the first page. It works as a. The sequential code decoding circuit 22 includes line memories 22a and 22b that store one line.

The DMA controller 24 is the system control unit 1
DMA transfer from line memory 22a or 22b to page memory 16 in response to instructions from 2;
It also performs DMA transfer from the page memory 16 to the printer interface 28. DMA
The controller 26 controls the buffer memory 20a or 20 in response to a command from the system control unit 12.
b is directly accessed to perform DMA transfer of the stored data to the code memory 18, or DMA transfer from the code memory 18 to the buffer memory 20c.

System control unit 1 through interface 28
2 is connected to a printer 30 as an example of recording means. The printer 30 includes an electrophotographic (or electrostatic recording) printing section and records a received image based on a reproduced image signal stored in the page memory 16.

Next, the specific operation of this embodiment will be explained with reference to FIGS. 1 to 4.

First, the operation of the main controller will be mainly explained along the flowchart of FIG.

(a) When the received original has a predetermined size and is less than one page When the modem 14 receives the code image signal, the main controller 12a starts the operation shown in FIG. That is, in step S1, the code picture signals received by the modem 14 are sequentially transferred to the buffer memory (initially 20a) and temporarily stored by interrupt processing by the modem clock.
In step S2, it is checked whether the first page has been recorded or not, that is, when a long document is received and the page memory 16 overflows,
It is determined whether the first memory content (first page) in 6 has been recorded. If the received original is of a predetermined size, it is determined that the first page has not been recorded, and in step S3, it is determined whether or not the code image signal reception operation has been completed. If it is determined that the reception has not been completed, the process advances to step S4. In step S4, it is determined whether the reproduced image signal decoded by the process described later is of the final line. Initially, it is determined that it is not the final line, and the process proceeds to step S5.

In step S5, it is determined whether the page memory 16 is overflowing, that is, whether it is full. Immediately after the start of reception, it is determined that there is no overflow, and decoding processing is performed in step S6. In this decoding process, one line of the received sequential code image signals stored in the buffer memory 20a is sequentially sent to the code decoding circuit 20a.
2, decoded into a reproduced image signal, and loaded into the line memory 22a. In step S7, it is determined whether the decoding process for one line has been completed. If decoding for one line has not been completed, the process advances to step S8. Step S8
, one buffer memory (currently
20a), it is determined whether all of the code image signals stored in 20a) have been decoded. In this case, it is determined that the decoding has not been completed, and the process proceeds to step S2.
Return to In this way, the operations of steps S2 to S8 are repeated until the decoding process for one line is completed.

When the sequential code decoding circuit 22 completes the decoding operation for one line, this is determined in step S7 and the process proceeds to step S9. In step S9, a switch is made to the line memory 22b to which next one line of image signals is to be loaded. In step S10, an image signal transfer request flag is set. As a result, the image signal for one line loaded in the line memory 22a is transferred to the page memory 16 in step S34, which will be described later.
DMA transfer will be performed. Next step S8
, and the above-described operations are repeated.

Thereafter, the operations of steps S2 to S10 described above are repeated for each line until the last line of the original is transferred to the page memory. Then, before the final line is detected in step S4, the step
One buffer memory in S8 (currently
When it is determined that the decoding for 20a) has been completed, the process advances to step S12. In step S12, the buffer memory is switched, and the process proceeds to step S13, where the load transfer request 1 flag is set, and the process returns to step S2. As a result, the code image signal is transferred from the buffer memory to the code memory 18 at the timing shown in FIG. 4a.
DMA transfer is performed.

While the above-mentioned operations are repeated, if the document is of a predetermined size and less than one page, at the time when the code image signal reception operation is completed, in step S3, the code image signal reception operation is terminated. When it is determined, reception termination processing is performed in step S11. Subsequently, when the code picture signal for one final line has been decoded, it is determined in step S4 that this is the final line, and the process proceeds to step S14. In step S14, a recording request flag is set. Based on this, one page is recorded in step S43 (see FIG. 3), which will be described later. Then, the process proceeds to step S15 via step S17, which will be described later.
In step S15, it is determined whether recording of one page (or one sheet) has been completed, and the process waits until recording of one page is completed.
Proceed to S16. In step S16, it is determined that recording based on all the received data (code image signals) has been completed, and the series of operations ends.

(b) When the received original is long If the received original is long, steps S1 to S13 are performed in the same way as when the received original is less than one page. In this case, before the final line is detected in step S4, it is determined in step S5 that the page memory 16 has overflowed, and the process advances to step S14. Further, since the reproduced image signal of the first page is not recorded immediately after reception, it is determined in step S2 that the recording of the reproduced image signal of the first page is not completed.

In steps S14 to S16, the recording request flag is set in the same manner as described above, and one page's worth (all contents of the image information stored in the page memory 16) is set.
Wait until recording is finished. However, even during this standby, image signals are sequentially transferred from the modem to the buffer memory 20a or 20b, and the transferred code image signals are the same as the code image signals received from the buffer memory in steps S17 to S20.
DMA transfer is performed. That is, step
In S17, it is determined whether one buffer memory is full or not, and if it is determined that either buffer memory 20a or 20b is full, the process advances to step S18, and the buffer memory is switched in step S18. Next, the main controller 12a instructs the DMA controller 26 to transfer, and in step S19, DMA transfer is performed from the buffer memory 20a or 20b to the code memory 18 as shown in FIG. Wait until the transfer is finished.

Then, in step S15, the process waits until the recording of one page is completed, that is, the entire contents of the page memory 16 have been recorded, and after it is determined in step S15 that the recording of one page has been completed, all data recording is completed in step S16. If it is determined that the code transfer request 1 has not been completed, the code transfer request 1 flag described above is set in step S13, and then the process returns to step S2. After the recording of the first page is completed, the steps are performed as shown in Figure 4b.
S2 to step S13, steps S21 and S22 to be described later,
In S23, decoding of the code image signal and transfer of the decoded image signal to the page memory 16 are repeated. Furthermore, step S2 to step S13, S21,
In the transfer of the code picture signal in S22, the received code picture signal is DMA transferred from the buffer memory 20a or 20b to the code memory 18 in step S23 and step S39, which will be described later. 20c, DMA transfer is performed in steps S8, S12, S13 and step S48, which will be described later.

That is, when it is determined in step S2 that the first page has been recorded, the process proceeds to step S21.
Proceed to. In step S21, the buffer memory 20
It is determined whether or not a or 20b is full. If it is full, the process proceeds to step S22; otherwise, the process proceeds to step S3. At this time, the steps described below
At S48, the code image signal received from the code memory 18 as a data source for decoding is transferred to the buffer memory 20c by DMA transfer. Then, the code image signal of this buffer memory 20c is transferred to step S3.
~ S8 decodes and DMA transfers to page memory 16. On the other hand, when either buffer memory 20a or 20b becomes full, in step S22,
The buffer memory 20a or 20b is switched and the process proceeds to step S23. In step S23, the code transfer request 2 flag is set, and the process proceeds to step S3. As a result, the code is stored in the code memory 18 at step S39, which will be described later, at the timing shown in FIG. 4b.
DMA transfer is performed.

After the decoding process progresses and the page memory 16 becomes full again, the above-described operation is performed.

During reception, the page memory 16
When it is full, it stops decoding and starts recording.
After recording is completed, decoding is restarted, the reproduced image signal is transferred to the page memory 16, and decoding and recording are performed alternately to confirm that recording of all received data has been completed.
If the determination is made in step S24, this operation ends.

Next, the operation of the sub-controller 12b will be mainly explained along the flowchart of FIG.

Before the image signal transfer request flag is set in step S10, and before the code transfer request 1 or 2 flag is set in step S13 or S23, the image signal transfer is performed in step S31. It is determined that the flag is not set, and the process proceeds to step S32.
At step S33, it is determined that the code transfer request 2 flag is not set, and at step S33, it is determined that the code transfer request 1 flag is not set, and the operations of steps S31, S32, and S33 are repeated.

On the other hand, if the image signal transfer request flag is set in step S10, this is determined in step S31, and the process advances to step S34. In step S34, sub controller 1
The image signal transfer command from 2b is sent to the DMA controller 2.
given to 4. Therefore, the DMA controller 24 directly accesses the line memory 22a or 22b, reads out one line of image signals, and transfers it to the page memory 16. Step S35
At this point, the process waits until the image signal transfer for one line is completed. Thereafter, the image signal transfer request flag is reset in step S36. step
In S37, it is determined whether the page memory 16 has overflowed. Before the page memory 16 overflows, it is determined that the page memory 16 has not overflowed, and the process proceeds to step S32, where the above-described operations are repeated.

By the way, in the state before the code transfer request 2 flag is set in step S23, this is determined in step S32 and the process proceeds to step S33. At this time, the above-mentioned step S13
If the code transfer request 1 flag is set in step S33, this is determined and the process advances to step S38. In step S38, it is determined whether recording of the image signal of the first page has been completed. If it is determined that the process has not been completed, the subcontroller 12
The code transfer command is sent from b to the DMA controller 26.
given to. The DMA controller 26 uses direct memory access to read the code image signal stored in the buffer memory 20a or 20b that is not being written, and transfers it to the code memory 18. In step S40, the process waits until the transfer is completed. When the transfer operation is completed, the code transfer request flag is reset in step S41, and then the process returns to step S31.

On the other hand, in step S37, the page memory 16
If it is determined that there has been an overflow, the process advances to step S42. In step S42, the process waits until the recording request flag is set in step S14. Thereafter, in step S43, the reproduced image signal for one page stored in the page memory 16 is given to the printer 30 via the interface 28, and recorded on paper of a predetermined size (print recording).
be done. In step S44, the recording request flag is reset. In step S45, all reproduced image signals stored in the page memory 16 are cleared. If it is determined in step S46 that recording of all received data has not been completed, the start address to which the next code should be transferred is calculated in step S47, and
The data is loaded into the internal memory 12c. Here, among the data transferred to the code memory 18 by DMA, the address corresponding to the code image signal at the time when the code memory 16 overflows is transferred from the code memory 18 to the buffer memory circuit 2.
Since this is the read address when transferring to 0, that address is calculated. After that, the process returns to step S31.

As described above, after the contents of the page memory 16 at the time of overflow are recorded (printed out), the code image signal to be recorded on the next page is read from the code memory 18, decoded, and then written to the page memory 16. There is a need. Therefore, steps S31, S32 and S33 mentioned above
Repeated operation or steps S31, S34 ~
If the code transfer request 1 flag is set again during the repeated operations of S37, S32, and S33, this is determined in step S33, and then the process advances to step S38. In step S38,
It is determined that the first page has been recorded,
Proceed to step S48. In step S48, the code picture signal transfer command and the start address data to be transferred are sent from the subcontroller 12b.
DMA controller 26. For this reason, the DMA controller 26 uses the code memory 18
is directly accessed to sequentially read out data corresponding to code image signals after the previous time when the page memory 16 overflowed. This data is written to buffer memory 20c. In step S40, the process waits until the transfer operation is completed, and then, in step S41, the code transfer request flag is reset, and then the process returns to step S31.

Furthermore, as mentioned above, after the recording of the first page is completed, the data is sequentially received and sequentially stored in the buffer memory 2.
The code image signal transferred and stored in 0a or 20b is transferred to the code memory 18. That is, when the code transfer request 2 flag is set in step S23, the process proceeds to step S39, where it is determined in step S32. In step S39, subcontroller 1
Code transfer command from 2b to DMA controller 2
given to 6. The DMA controller 26 reads out the code image signal stored in the buffer memory 20a or 20b that is not being written in by direct memory access, and transfers it to the code memory 18. Then, in step S40, the process waits until the transfer is completed. When the transfer operation is completed, the code transfer request flag is reset in step S40, and then the code transfer request flag is reset in step S40.
Return to S31.

Thereafter, in the same manner as described above, the received code image signal is sequentially decoded into a reproduced image signal by the code/decoder circuit 22, and the reproduced image signal for one line is stored in the line memory 22a or 22b. are loaded alternately. and line memory 22a
Or the playback image signal loaded in 22b is
Page memory 1 by DMA controller 24
Transferred to 6. When the decoding and recording processing of all received data is completed, the step
This is determined in S46 and the operation ends.

(G) Effects of the Invention As described above, in the present invention, in parallel with storing the reproduced image signal decoded from the received code image signal in the first storage means, the code format when the code image signal is received is If the first storage unit does not overflow and the reception is completed, that is, if the original is within a predetermined size, recording is started immediately; Decryption processing is possible. Furthermore, when an overflow occurs in the first storage means during reception, that is, when a long original is received, recording of the reproduced image signal and decoding processing of the coded image signal are alternately repeated during reception. Since long originals are recorded, the processing time for long originals can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a facsimile apparatus according to an embodiment of the present invention. FIG. 2 is a flow diagram for explaining the operation of the main controller. FIG. 3 is a flow diagram for explaining the operation of the sub-controller. FIG. 4 is a timing diagram showing the transfer state of the code image signal in each state. 12... System control unit, 16... Page memory, 18... Code memory, 20... Buffer circuit, 22... Sequential code decoding circuit, 24, 26...
...DMA controller, 28...interface, 30...printer.

Claims (1)

[Claims] 1. Decoding means for decoding the received encoded signal, first storage means for storing the decoded signal decoded by the decoding means, and decoding stored in the first recording means. storage means for storing based on a signal; second storage means for storing the received encoded signal; overflow detection means for detecting that the storage state of the first storage means has overflowed; and the overflow detection means. After outputting, the second
A facsimile apparatus, comprising a transfer means for transferring the encoded signal stored in the storage means to the decoding means, in response to an output of the overflow detection means,
At the same time, stopping the decoding operation of the decoding means,
Stopping the writing in the first storage means, and recording all the decoded signals stored in the first storage means by the recording means, and immediately after the recording is finished, by the transfer means, A facsimile apparatus characterized in that the encoded signal stored in the second recording means is transferred to the decoding means, and the decoding operation of the decoding means and writing to the first storage means are restarted.