JPH03250862A - Image communication device - Google Patents

Abstract

PURPOSE:To improve the communication speed by implementing the communication procedure for deciding the transmission speed with a receiver again even during picture transmission and using a transmission speed as fast as possible so as to send a picture. CONSTITUTION:The picture communication equipment consists of a microprocessor (MPU) 1, a memory 2, a printer 3, a large capacity storage device 4, a ROM 5, a scanner 6, an operation display section 7, a MODEM 8, a network controller (NCU) 9 and a bus 10. After a picture data in a prescribed unit is sent, since a prescribed procedure signal for transmission speed decision communication procedure is sent to a receiver side, the communication procedure for deciding the transmission speed with a receiver is implemented again even during picture transmission and the picture transfer is executed by adopting a transmission speed as fast as possible. Thus, the communication speed is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image communication device, in particular, to an image communication device, which performs a communication procedure for determining the transmission speed with a receiving device before image transmission, and determines the transmission rate by this communication procedure. The present invention relates to an image communication device that transmits images using transmission speed.

[Prior Art] When transmitting an image using a facsimile device, if an error occurs in the image information received by the receiving device, such as when the line condition is poor, the receiving device cannot reproduce an accurate image.

Therefore, in conventional 63 facsimile machines, when the receiving side returns image information to an image, it counts the number of bits in one line to find an erroneous line, and if the number of lines exceeds a certain value, the page An RTN (return to procedure) signal was used to inform the transmitting side that the image information would be retransmitted.

[Problem to be Solved by the Invention] On the other hand, once the transmission speed is determined in Phase B, all documents are transmitted at a constant speed unless a mode change such as a paper size change occurs. Once it was determined that 2,400 bps was used, all subsequent image information was transmitted at 2,400 bps.

However, in the above conventional example, even if the line condition temporarily deteriorates in Phase B, image information is transmitted at the transmission speed determined in Phase B, so when transmitting image information for a long time, it is difficult to Even if the line condition improves, the transmission speed cannot be increased, and the time required to transmit image information becomes long.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an image communication device that can perform communication as fast as possible even if the line status changes during communication.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, before image transmission, a communication procedure for determining the transmission speed is performed with the receiving device, and the transmission rate determined by this communication procedure is In an image communication device that performs image transmission using a transmission rate, the apparatus is provided with a control means for transmitting a predetermined procedure signal for performing the transmission rate determination communication procedure to a receiving side after transmitting a predetermined unit of image data. The configuration was adopted.

[Operation] According to the above configuration, even during image transmission, the communication procedure for determining the transmission speed is performed again with the receiving device,
Image transmission can be performed using as high a transmission rate as possible.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows the configuration of an image communication device employing the present invention.

In FIG. 1, reference numeral l denotes a microprocessor (hereinafter referred to as MPU) that controls the entire device, and is connected to a memory indicated by reference numeral 2.5 via a bus IO. The memory 2 is a RAM that temporarily stores image information and serves as a work area used for processing by the MPU 1. ROM 5
stores the processing procedure described below as an MPUI control program.

The following members are connected to the bus IO.

Reference numeral 3 is a printer that prints out the received image; reference numeral 4 is a printer that prints out the received image;
is a large-capacity storage device for storing image information and device-specific parameters, and is composed of a hard disk device and the like.

Reference numeral 6 is a scanner consisting of a CCD line sensor document conveyance system for reading images, reference numeral 7 is an operation display section consisting of a keyboard, display, etc. for interfacing with the operator, and reference numeral 8 is an input/output of digital data through a line. 9 is a network control unit (NCU) for making and receiving calls, maintaining loops, etc.

Next, image transmission control in the above configuration will be explained with reference to FIGS. 2 and 3. FIG. 2 shows the MPUI control program stored in the ROM 5.

FIG. 2 shows the procedure after calling and line connection (phase A) are performed according to a known procedure. First, in step S1, after determining the transmission mode in phase B, training and TCF signals are performed. The transmission rate is determined (period t1 in FIG. 3).

At this time, if the line condition is poor and phase alignment fails,
Since an FTT (training failure) signal is returned from the receiving side, the transmission speed can be changed from 9600 bps to 7200 bp.
Lower it to s and try training/TCP again from the sender side.
Send a signal. Repeat this fallback operation until phase alignment is performed normally (up to 2400 bps)
. If the line condition is poor at this point, subsequent transmission of image information is performed at a low speed. In the case of Fig. 3, during period tl, the line condition deteriorates as follows, and the transmission rate is 4
It has a fallback to 800 bps.

On the other hand, when a CFR (receiving readiness confirmation) signal is returned from the receiving side, phase matching has been completed and the transmission speed has been determined, so the next step is to move to phase C and transmit image information for 1 page (step S2 , and period t3 in FIG.

When the transmission of the image information is completed, the amount of information of the image just transmitted is checked in step S3.

If the amount of information is small, there is a low possibility that the line status has changed. The facsimile communication is carried out under the same control as the conventional one.A description of this conventional processing will be omitted.

On the other hand, if it is determined in step S3 that the image information of the next page or subsequent pages is equal to or greater than a certain amount, the process moves to step S6.

The reason why the amount of image information is checked in step S3 is that the amount of image information is directly reflected in the communication time. Specifically, when restarting facsimile communication from the beginning of Phase B using the EOM signal, it takes at least about 4 seconds to move from the beginning of Phase B to the image transmission phase, while the Funny's D signal (for example, MPS and MCF)
Since it takes about 2 seconds, there is no point in implementing the present invention when the amount of image information of the next page to be transmitted does not exceed 2 seconds, so proceeding from step S3 to step S4, the method is compared to conventional facsimile communication. is checked, and if there is no next page, the process advances to step S4 and the same control as before is performed.

Note that if the transmission speed currently in use is the maximum speed of this device or the maximum speed that can be used by the receiving side, the process moves from step S3 to step S54.

If there is a next page, a phase D command is sent to the receiving side as an E OM' (message end) signal in step S7. In this case, in step S8, the transmission status is confirmed by the MCF (message confirmation) signal of the other station (period t3 in FIG. 3).

If there are few errors in the transmitted document (or if the transmission is successful, the MCF signal is returned from the receiving side, so if the MCF signal is received, the process returns to the beginning of phase B in step S8 and repeats the process from step Sl).

On the other hand, if the MCF signal is not received, the process returns to step S2 and continues communication at the same transmission speed, as in conventional facsimile communication. In the case of Figure 3, the period t4
Training is performed again at , and since the line condition is now good, the transmission rate is reset to 9600 bps.

According to the above embodiment, when transmitting a certain amount of communication data or more, the phase D signal sent by the transmitting side after transmitting one document is set to EOM each time, so that optimal transmission is achieved for each document. Speed can be determined. Therefore, even if the line condition improves after fallback as in the past, image information will not be sent forever at a slow transmission speed (this has the effect of shortening the transmission time. In the example, once the transmission rate is 4800 bp
However, the EOM transmission returns to phase B again and the communication speed is increased to 9600 bps, making it possible to quickly transmit images.

Moreover, according to the above embodiment, in step S3,
Since the above-mentioned control is performed only when the image data is equal to or higher than a certain value, the communication procedure is not wasted and the transmission state as high as possible can be maintained.

[Effects of the Invention] As is clear from the above, according to the present invention, a communication procedure for determining the transmission rate is performed with the receiving device before image transmission, and the transmission rate determined by this communication procedure is used. An image communication device that transmits an image by using a control means that transmits a predetermined procedure signal for performing the transmission rate determination communication procedure to a receiving side after transmitting a predetermined unit of image data. Therefore, even during image transmission, the communication procedure for determining the transmission speed is performed again with the receiving device, and the image transmission can be performed using the highest possible transmission speed. can be significantly improved,
Furthermore, it is possible to provide an excellent image communication device that can reduce communication costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an image communication device adopting the present invention, FIG. 2 is a flowchart showing the transmission control procedure of the device in FIG. 1, and FIG. 3 is the device in FIG. FIG. 2 is an explanatory diagram showing a signal sequence exchanged between devices. l-...MPU 2...Memory 3...Printer 4...-Mass storage device 5...ROM
6...Scanner 7-...Operation display section 8...
・Modem 9-...NCU Fax! AI's 1"O-, Fuki 1st figure

Claims (1)

[Scope of Claims] 1) An image communication device that performs a communication procedure for determining a transmission rate with a receiving device before transmitting an image, and transmits an image using the transmission rate determined by this communication procedure, An image communication apparatus comprising: a control means for transmitting a predetermined procedure signal for performing the transmission rate determination communication procedure to a receiving side after transmitting a predetermined unit of image data. 2) A control means is provided for determining whether or not to transmit a predetermined procedure signal for performing the transmission rate determination communication procedure after transmitting the predetermined unit of image data, depending on the amount of image data to be transmitted. The image communication device according to claim 1.