JP3389698B2 - Facsimile machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus, and more particularly to a facsimile apparatus which corrects a data error at the time of data transmission by retransmitting correct data in facsimile communication. . [0002] In recent years, ITU-T Recommendation T. 30 ANN
EXC recommends a new communication protocol (hereinafter referred to as G3C protocol). The G3C protocol has been proposed as a combination of the concepts of the G3 protocol and the G4 protocol. As prior art, an error control method of full-duplex communication is disclosed in Japanese Patent Publication No. 5-48.
No. 013 has been proposed. In this publication, when an error frame is detected on the receiving side, a tone signal requesting retransmission is transmitted to the transmitting side by full-duplex communication. Also,
The transmitting side that has received the tone signal requesting retransmission, measures the frame in which the error has occurred from the time until the receiving side transmits the tone signal and receives the tone signal, and determines the frame in which the error has occurred. After that, it is resent immediately. [0003] However, G3C
In a facsimile apparatus to which the protocol is applied, it is not known which block is transmitted in response to a partial page request (hereinafter referred to as PPR) command for the occurrence of an error. That is, just because the receiving side transmits the PPR command does not necessarily mean that the transmitting side immediately retransmits the corresponding block, and that the transmitting side has already started transmitting the next block. There is. The technique disclosed in Japanese Patent Publication No. 5-48013 is completely unrelated to the G3C protocol.
This is devised on the premise that the transmitting side immediately retransmits a block in response to a retransmission request from the receiving side. Therefore, as described above, there is a problem that when the transmitting side does not know which block is to be retransmitted, it cannot cope at all. In the above-described conventional facsimile apparatus, when the error of one block has disappeared, the process proceeds to the next page. For this reason, control could be performed if the reception buffer was one block (64 Kbytes).
In a facsimile machine to which the G3C protocol is applied,
Even if there is an error, there is a possibility that the program may proceed to the next block or page, and the conventional facsimile machine does not consider such an operation at all and cannot cope with it. In the above-described conventional facsimile apparatus, when there is a retransmission request for an erroneous block,
It is resent back to the block where the error occurred. So if the next block has already been sent,
This block is also transmitted, and there is a problem that useless transmission is performed. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-described problem of the conventional technology and to respond to a data retransmission request for a data error in any order and in which data is transmitted. A facsimile machine is provided. [0007] To achieve the above object, the present invention provides a first storage means for storing one block or one frame of received image data, and a plurality of received image data. Is stored in an area corresponding to each block or frame in the order received, address data relating to received image data stored in the second storage means, and a post message command. Management data storage means for storing a page number and a block or frame number stored therein, and data corresponding to received image data stored in the first storage means, wherein the management data storage means is searched. Search means for searching whether or not the second message is stored, and a second storage device corresponding to the page number and block or frame number of the post message command. It is characterized in that a transfer means for transferring the received image data stored in the first storage means is provided in the area of the stage. According to the present invention, the received image data is temporarily stored in the first storage means one block or one frame at a time, and after searching the management data storage means, the received image data is stored in one block. Alternatively, the data is sequentially transferred to and stored in the area in the second storage means for each frame. As a result of the search, when the page number and the block or frame number of the post message command of the received image data do not exist in the management data storage unit, these are stored in correspondence with the area number of the second storage unit. I do. As a result,
Even if the retransmitted image data is sent out of order, the received image data is accurately stored in the area in the second storage unit by referring to the management data stored in the management data storage unit. It becomes possible. An embodiment of a facsimile apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 2 is a block diagram showing a schematic configuration of a facsimile apparatus to which the present invention is applied. In the figure, 11 is a CPU for controlling the entire facsimile apparatus, 12 is a RAM as a work area used by a control program, 13 is an operation display device for an operator to operate the facsimile apparatus, 14 is a document for transmission or a document for copying. A reading device 15 for recording the copy original or the received image, an image processing device 16 for encoding, decoding, or scaling image signals; and a storage device 17 for storing image information. An image storage device 18; a system control unit 18 in which the CPU 11 controls the entire system of the facsimile machine and stores a program for controlling the facsimile device; and 19, a digital controller for controlling communication suitable for a digital network. Communication control device, 20
Is an analog communication control device that controls communication suitable for an analog network, and has an automatic transmission / reception function. Reference numeral 21 denotes a digital network interface for connecting a facsimile apparatus to a digital network, 22 denotes a modem having a function of switching between a low-speed mode function and a high-speed mode function, 23 denotes an analog network interface for connecting the facsimile apparatus to an analog network, 24 Is a system bus for exchanging data with each other, and 25 is a line switching control device for connecting external line interfaces such as the digital network interface 21 and analog network interface 23 to a plurality of internal communication circuits. FIG. 1 is an explanatory diagram showing an outline of functions of an embodiment of the present invention. In the figure, reference numeral 1 denotes a temporary buffer for storing one block of received image data, and 2 denotes a storage buffer N for storing a plurality of blocks of received image data for each block.
o. n, where n is a storage buffer for storing data corresponding to n = 1, 2, 3,...
Address data related to the received image data stored in the
This is a management data storage unit that stores a page number, a block number, or a frame number added to the post message command as necessary. The temporary buffer 1 corresponds to, for example, a RAM 12, the storage buffer 2 corresponds to an image storage device 17, and the management data storage unit 3 corresponds to, for example, a system control unit 18. Next, the operation of data reception control according to the present embodiment will be described with reference to the drawings. FIG. 3 is a diagram showing an example of transmission and reception of commands, image information, and the like between facsimile machines of the present invention. Note that “3 ×” at the beginning of each command in FIG. 3 means that the command is transmitted three times. FIGS. 4 and 5 are flowcharts showing the operation of data reception control according to this embodiment. First, in step S1, it is determined whether there is an incoming call from another facsimile machine. In step S2, it is determined whether or not an exchange identification procedure (hereinafter, referred to as XID) command has been received. If the determination is affirmative, the process proceeds to step S3, where the XID command, the non-standard A multi-frame command {XID, (NSF), (CSI), D> in which a function signal (hereinafter, NSF) command, a called terminal identification signal (hereinafter, CSI) command, and a digital identification signal (hereinafter, DIS) command are combined.
IS｝ is transmitted. In step S4, it is determined whether a digital command signal (hereinafter, DCS) has been transmitted. If this determination is affirmative, the process proceeds to step S5, while if negative, the multi-frame command is transmitted again. Here, in FIG. 3, since the DCS command has not been transmitted from the transmitting side with respect to the first multi-frame command, the determination in step S4 is negative, and the multi-frame command is transmitted again. Since the DCS command has been transmitted from the transmitting side in response to the second multi-frame command, and the receiving side has received the DCS command, the determination in step S4 is affirmative, and the process proceeds to the next step. In step S5, the received image data, that is, facsimile coded data (hereinafter, referred to as FCD) is stored in the temporary buffer 1. In step S6, it is determined whether one block of the received image data has been received. If this determination is affirmative, the process proceeds to step S7, where the post message command (hereinafter, P
It is determined whether or not a PS-Q command has been received. The PPS-Q command is added with a page number, a block number, and a frame number, and includes a null signal of a partial page signal (hereinafter, referred to as PPS-NULL) and a multi-page signal of a partial page signal (hereinafter, PPS-MP).
S), a partial page signal procedure end signal (hereinafter referred to as P
PS-EOP), and a message end signal of a partial page signal (hereinafter, referred to as PPS-EOM).
In step S7, as shown in FIG.
Since UL (1,1, z) has been transmitted, this determination is affirmative, and the process proceeds to step S10 in FIG. here,
Returning to step S6, if the judgment is negative,
Proceeding to step S8, it is determined whether or not a command has been received, and if this determination is affirmative, processing proceeds to step S9. In step S9, it is determined whether a PPS-Q command has been received. If the determination is affirmative, step S10
Proceed to. On the other hand, if step S8 or S9 is negative, the process returns to step S5, and the operation of storing the received image data in the temporary buffer 9 is continued. Next, in step S10, the received PP
The search means provided in the system control unit 18 searches whether information corresponding to the page number and block number of the SQ command is already stored in the management data storage unit 3. In step S11, the information is stored in the management data storage unit 3 based on the search result.
Is determined. If this determination is negative, the process proceeds to step S12, where the accumulation buffer 2
The received image data stored in the temporary buffer 1 is transferred to the unused area and the uppermost area by, for example, a transfer unit provided in the system control unit 18. Subsequently, in step S13, the storage buffer No. of the storage buffer 2 to which the received image data has been transferred. , The PP
The page number and block number of the SQ command
It is stored in the management data storage unit 3. Here, returning to step S11, if the judgment is affirmative, the process proceeds to step S15, where the corresponding storage buffer No. of the storage buffer 2 is set. In the area of
The normal received image data stored in the temporary buffer 1 is transferred. In this case, the fact that the information is stored in the management data storage unit 3 means that some kind of received image data, for example, erroneous received image data is already stored in the accumulation buffer 2. For this reason,
The new normal received image data will be overwritten.
In step S14, the received image data stored in the accumulation buffer 2 is subjected to a frame check sequence (FC
S) A check is performed to determine whether retransmission is required. If this determination is affirmative, that is, if there is an error in the received image data, the flow advances to step S16 to transmit a PPR command. On the other hand, if the determination is negative, that is, if normal received image data has been obtained, the process proceeds to step S17, and a message confirmation (hereinafter, MCF) command is transmitted. Here, the operation of transmitting and receiving commands and image data of the facsimile apparatus to which the present invention is applied will be described with reference to FIGS. First, the PPS-NULL (1, 1, 1) transmitted to the temporary buffer 1 is transmitted.
z) is stored in the storage buffer No. of the storage buffer 2. 1 and store the page data, page number = 1, block number = 1 and storage buffer No. =
1 is stored in the management data storage unit 3. Then, PPS
Similarly, for the FCD frame of the MPS (1, 2, y), the accumulation buffer No. of the accumulation buffer 2 is used. 2 and store it, page number = 1, block number = 2 and storage buffer No. = 2 is stored in the management data storage unit 3. Here, the PPS-NULL
The FCD frame of (1,1, z) and PPS-MPS (1,2, y) was subjected to FCS check, and as a result, there was a data error.
(1, 1, z) is transmitted. Next, the FPS of the PPS-MPS (2, 1, x)
Similarly to the above-described frame, the CD frame has the storage buffer No. of the storage buffer 2. 3 and store the same, page number = 2, block number = 1 and storage buffer No. = 3 is stored in the management data storage unit 3. This FCD frame transmits MCF (2, 1) because there was no data error as a result of the FCS check. Subsequently, the accumulation buffer No. of the accumulation buffer 2 is similarly set for the FCD frame of the PPS-EOP (3, 1, w). 4 and stored therein, and the page number = 3, the block number = 1, and the storage buffer No. =
4 is stored in the management data storage unit 3. As a result of a data error as a result of the FCS check, the PPR (3, 1,
Send a). Next, corresponding to the PPR, PPS-E
When the FCD error frame of OP (3, 1, a) is retransmitted, the search means searches the management data of the management data storage unit 3 and searches for the management data corresponding to page number = 3 and block number = 1. The accumulation buffer No. of the accumulation buffer 2 Remove 4. Thus, the storage buffer No. Area 4 is rewritten with the retransmitted frame. As a result of the FCS check, no data error is detected, so that MCF (3, 1) is transmitted. Subsequently, PPS-MPS (1, 2, v) and PPS-MPS
As for the FCD error frame of (1, 1, z), similarly to the FCD error frame of PPS-EOP (3, 1, a), the accumulation buffer No. 2 and No. 1 area is rewritten with the retransmitted frame, and the MCF
(1,2) and MCF (1,1) are transmitted. Although the PPS-MPS (1, 1, z) command is transmitted twice, the MCF
Since (1, 1) was not transmitted, PPS-MP is transmitted again.
It is merely transmitting S (1,1, z). As described above, in the G3C protocol, the transmitting side retransmits the FCD frame in any order with respect to the PPR transmitted from the receiving side, but according to the present embodiment, the FCD frame is added to the post message command. Storage buffer N based on the current page number and block number.
o. Is searched, and the received FCD frame is stored in the corresponding storage buffer No. , So that the receiving side can obtain the image information in the correct order. As a result, if this is displayed on a display device or printed by a printing device, a clear image or a printed document can be obtained. Further, only one temporary buffer capable of storing one block of data is prepared.
Since normal received image data can be obtained in a correct order, there is an effect that it can be realized by preparing a small memory area. In addition, since retransmission of normal image data can be avoided, the problem of unnecessary transmission is eliminated, and retransmission of normal data for a data error can be efficiently performed. In the present embodiment, data is stored for each block. However, the present invention is not limited to this, and data may be stored for each frame. In this case, if data is accumulated for each frame, error correction can be performed more finely, and unnecessary data transmission is reduced as compared with the case where data is accumulated for each block. Can be performed efficiently. As is apparent from the above description, according to the present invention, image data that can be normally received is stored in the second image data.
Can be accurately stored in the area of the storage means,
Also, the received image data retransmitted out of order with respect to the PPR command can be received in conformity with the normally received image data. As a result, a receiver suitable for image data received according to the G3C protocol can be provided. The present invention can be realized by preparing only one small-capacity first storage means capable of storing data of one block or one frame. In addition, the problem of unnecessary transmission of image data can be solved, and normal data retransmission for a data error can be efficiently performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an outline of functions of an embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of a facsimile apparatus to which the present invention is applied. FIG. 3 is an explanatory diagram showing an example of transmission and reception of commands, image information, and the like between facsimile apparatuses of the present invention. FIG. 4 is a flowchart illustrating an operation of data reception control according to the embodiment; FIG. 5 is a flowchart showing an operation continued from FIG. 4; [Description of Signs] 1 temporary buffer, 2 storage buffer, 3 management data storage unit, 11 CPU, 12 RAM, 13 operation display device, 14 reading device, 15 printing device, 16 printing device
Image processing device 17 Image storage device 18 System control unit 19 Digital communication control device 20 Analog communication control device 21 Digital network interface 22
... Modem, 23 ... Analog network interface, 2
4 ... System bus, 25 ... Line switching controller.

Continuation of front page (56) References JP-A-3-286675 (JP, A) JP-A-1-164167 (JP, A) JP-A-3-132158 (JP, A) JP-A 1-220967 (JP) JP-A-2-53381 (JP, A) JP-A-1-292938 (JP, A) JP-A-5-91091 (JP, A) JP-A-3-247136 (JP, A) 2-205130 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/32-1/36 H04N 1/42-1/44 H04L 1/00 H04L 1/08-1 /twenty four

Claims (1)

(57) [Claim 1] In a facsimile apparatus which corrects a data error by retransmitting correct data in response to a data error at the time of data transmission, a received image for one block or one frame is provided. A first storage unit for storing data; a second storage unit for storing a plurality of received image data in an area corresponding to each block or frame in the order of reception; and a second storage unit for storing the plurality of received image data in the second storage unit. Management data storage means for storing address data relating to received image data, a page number and a block or frame number added to a post message command, and searching for the management data storage means, the first storage means The data corresponding to the received image data stored in
Retrieval means for retrieving whether or not the received image data is stored; and received image data stored in the first storage means in an area of the second storage means corresponding to a page number and a block or frame number of the post message command. A transfer unit that transfers the received image data. If it is determined that the received image data is already stored in the first storage unit,
The received image data stored in the first storage means is transferred to the corresponding area of the second storage means, and when it is determined that the received image data is not stored, the page number and the block or frame number are stored in the corresponding area. A facsimile apparatus, wherein the received image data is stored in a management data storage unit, and the received image data stored in the first storage unit is transferred to a corresponding area of the second storage unit.