JPS61116469A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To shorten a transmission time by informing the receiving side with one-stage accelerated digital image transmission speed from the analyzed result of a decoding error degree informing signal received by a modulator/demodulator when the decoding error is a specified value or below and providing a control circuit for retraining of a demodulator circuit. CONSTITUTION:When a decoder 3 monitors received image signal data by the data group and recognizes the decoding error due to a noise on a facsimile communications circuit, it outputs said error to a counter 4, which counts decoding errors. After the 1st communications control circuit 5 finishes decoding image signal data of one page, it gives to the modulator circuit 1 instructions for generating and transmitting a communications sequence signal for informing a transmitting side 10' of the degree of the decoding error with the aid of the value outputted by the counter 4. An analysis circuit 6' analyes the informed communications sequence signal data. When the error count value is below the specified one, the 2nd communications control circuit 7' indicates the receiving side 10 the higher image signal transmission speed than the previous time. The modulator circuit 1 at the receiving side 10 is trained at the new image signal transmission speed, which is improved, and the transmission time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile machine, and more particularly to a control system for special picture signal communication.

[Prior Art and Problems to be Solved by the Invention] Conventionally, this type of facsimile apparatus has been known to transmit digital image signals at a slower speed than when the facsimile communication line is in good condition due to the influence of noise. to send the image signal. but.

Noise generation on facsimile communication lines is often caused by burst-like external influences, and even if the noise decreases during 2-picture signal transmission and the 9 line returns to a good condition,
The drawback was that facsimile communication continued and ended at a slow speed.

According to the present invention, during two-picture signal communication in facsimile communication, when the transmitting side determines that the state of the facsimile communication line has been restored based on a decoding error degree notification signal from the receiving side, the transmitting side instructs the receiving side to increase the speed by one level. Then, the demodulation circuit on the receiving side is retrained to increase the 8-picture signal transmission speed,
An object of the present invention is to provide a facsimile device that reduces transmission time.

[Structure of the invention]

According to the present invention, a modulation/demodulation circuit for transmitting and receiving digital image signals on a facsimile communication line.

a decoding device that decodes the digital image signal received by the modulation/demodulation circuit; a counter that counts decoding errors of the received digital image signal caused by noise on the facsimile communication line; a signal generating circuit that generates a decoding error degree notification signal for notifying the degree of decoding error, provides the decoding error degree notification signal to the modulation/demodulation circuit to transmit it on the facsimile communication line, and receives the signal by the modulation/demodulation circuit; an analysis circuit that analyzes the decoding error degree notification signal; and when the analysis result by the analysis circuit indicates that the decoding error is below a specified value, notifying the receiving side of a digital image signal transmission speed that is one step faster than the previous time; A facsimile apparatus is obtained, characterized in that it has a control circuit for retraining a demodulation circuit on the receiving side.

That is, in one aspect of the present invention, when the external influence is reduced during facsimile image signal communication and the state of the facsimile communication line is restored, the transmitting side receives and analyzes the signal sent by the receiving side indicating the degree of decoding error. . As a result, if it is determined that the conditions of the two lines are better than before, it notifies the receiving side of a higher image signal transmission rate, and then immediately retrains the receiving side's demodulation circuit at the new image signal transmission rate and performs training. If successful, the image signal is transmitted at that transmission speed (this is called the step-up function). In this way, the above-mentioned conventional drawbacks are eliminated, the two-image signal transmission speed is increased, and the transmission time is shortened.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, two facsimile machines 10 and 10' are shown according to one embodiment of the present invention. A receiving facsimile machine is indicated at 10.

The sending facsimile machine is indicated at 10'.

Both facsimile machines 1o and 10' have exactly the same configuration, but the decoding device, counter, and first communication control circuit in the sending facsimile machine 10' are omitted.

In the figure, ■ and 1' are modulation/demodulation circuits for transmitting and receiving digital image signal data and communication procedure signals, 3 is a decoding device that decodes the image signal data received and demodulated by the modulation/demodulation circuit 1, and 4 is a decoding device. A counter 5 that counts decoding error outputs from the device 3 is a first communication control circuit that creates two communication procedures based on the output from the counter 4.

6' is an analysis circuit that analyzes the received communication procedure signal; 7'
is a second communication control circuit that outputs an output to the modulation/demodulation circuit 1' for retraining the demodulation circuit on the receiving side based on the output of the analysis circuit 6. 6 is an analysis circuit similar to 6' described above, and 7 is a second communication control circuit similar to 7' described above.

In the receiving facsimile device 10, the decoding device 3 monitors the received image signal data for each predetermined data group, and if it detects a decoding error due to noise on the facsimile communication line, it outputs it to the counter 4, Counter 4 counts the number of decoding errors. After the first communication control circuit 5 has finished decoding the image signal data for one page, the first communication control circuit 5 starts the counter 4
Based on the output value, an instruction is given to the modulation circuit 1 to create and send a communication procedure signal (ie, a decoding error degree notification signal) for notifying the transmitting side 10' of the degree of decoding error. That is, the first communication control circuit 5 serves as a circuit for generating a decoding error degree notification signal. Sending side 10'
receives the communication procedure signal sent from the receiving side 10 from the demodulation circuit 1'.

The analysis circuit 6' is notified. The analysis circuit 6' analyzes the notified communication procedure signal data, and when the error count value becomes less than the specified value, notifies the second communication control circuit 7'. The second communication control circuit 7' is connected to the receiving side 10.
A procedure signal for instructing a higher image signal transmission speed than the previous one is created and sent to the modulation/demodulation circuit 1'. Modulation circuit 1
' modulates the notified procedure signal and transmits it to the receiving side 10, and trains the demodulation circuit 1 on the receiving side 10 at the new image signal transmission rate. If the training is successful, the receiving side 10
notifies the sending side 10' of an acknowledgment by means of a procedure signal. The transmitting side 10', which has received the acknowledgment, transmits a 9-image signal for the second page to the receiving side at the newly determined image signal transmission speed. Note that the analysis circuit 6' may be placed between the receiving side counter 4 and the first communication control circuit 5 to determine whether step-up is possible.

The same effect as in the above case can be achieved.

When the state of the facsimile communication line is restored as described above, it is possible to increase the 9-picture signal transmission speed and shorten the transmission time.

In other words, - For example, a device having a modem with a maximum transmission capacity of 9,600 bits/second can transmit up to 4,800 bits/second due to the influence of single-line noise.
If you start facsimile communication by falling back to 9600 bits/second and the line condition becomes good during the second communication, and you step up to 9600 bits/second, the communication speed will double.
This more than makes up for the wasted time required for step-up communication procedures. As a result, the larger the amount of data in subsequent facsimile communications, the higher the communication efficiency.

〔Effect of the invention〕

As described above, the present invention has the effect that image signal communication can be performed at a faster transmission speed when the quality of the facsimile communication line is improved by monitoring decoding errors on the receiving side.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention. 1.1'...Modulation/demodulation circuit, 3...Decoding device, 4.
... Counter, 5... First communication control circuit, 6 and 6'... Analysis circuit, 7 and 7'... Second communication control circuit, 10... Receiving side facsimile device, 10'・
...The sending facsimile device.

Claims (1)

[Claims] 1. A modulation/demodulation circuit for transmitting and receiving a digital image signal over a facsimile communication line, a decoding device for decoding the digital image signal received by the modulation/demodulation circuit, and the received digital image signal caused by noise on the facsimile communication line. A counter for counting decoding errors, and a decoding error degree notification signal for notifying the transmitting side of the decoding error degree according to the output of the counter, and the decoding error degree notification signal is given to the modulation/demodulation circuit to a signal generation circuit for sending out on a facsimile communication line; an analysis circuit for analyzing the decoding error degree notification signal received by the modulation/demodulation circuit; and when the analysis result by the analysis circuit indicates that the decoding error is less than a specified value. 1. A facsimile apparatus comprising: a control circuit for notifying a receiving side of a digital image signal transmission speed that is one step faster than the previous time, and retraining a demodulation circuit on the receiving side.