JPS5887969A - Communication method of facsimile device - Google Patents

Abstract

PURPOSE:To attain the correspondence between transmission and reception even during the transmission of a picture, by forming a signal stop period to make the transmitter side facsimile device receivable between specified picture scanning lines. CONSTITUTION:A controller 1 switches a mode changeover switch 6 from (a) to (b) during the normal transmission when a picture signal for, e.g., 10-lines' share is transmitted. If no flag transfer is detected from the receiver side during the ''window'' period T, the controller 1 at the transmitter side 1 is switched to (a), an original feeding roll 2 is started, data transfer from the reader 1' to the buffer memory 3 is started and a picture signal for 10-lines' share is transmitted. Further, when a failure occurred at the receiver side, and an emergency stop button 13, e.g., is depressed, the controller 11 at the reception side is switched to (c), and starts the transfer of flag after the system is switched to the transmission mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication method for a facsimile machine that employs a half-duplex communication method.

In conventional facsimile machines using half-duplex communication, it is difficult for the receiver to stop the facsimile machine while the transmitter is transmitting an image. In other words, conventionally, the transmission from the receiving side is 9+tl +
On the other hand, a method has been proposed in which a special frequency is transmitted backwards, and the transmitter side that is transmitting an image detects and stops the reversely propagating frequency, but the frequency is attenuated through the line. Detecting the component from the transmitted image signal is generally (
This has the disadvantage that the receiving circuit of the fax machine becomes complicated. In addition, with facsimile machines that do not have a stop function from the receiving side, communication between operators is not possible until the sending side finishes transmitting the image, and it is not necessary if the receiving side cannot receive normal images (capturing two lines) It turns out.

Therefore, the present invention has been made in view of the above points, and provides a communication method for a facsimile machine in which a stop function is provided from the receiver side to the transmitter side during image reception without changing the circuit configuration of the conventional facsimile machine. The purpose is to

According to the present invention, in order to achieve this object, a no-signal period is formed between predetermined image scanning lines, and a transmitter-side facsimile device is placed in a receiving state during this no-signal period. According to the present invention, during this no-signal period, the receiver side sends a signal to the transmitter side to stop the image failure signal.

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 shows the structure of image information transmitted and received in a facsimile machine, and in the figure, an image signal A of one scanning line is composed of a synchronizing signal A1 and image information A2. Such image signals are transmitted continuously, but as long as the transmitting side continues to transmit a series of signals, it becomes difficult for the receiving side to detect upstream messages. Therefore, in order to solve this problem, in the present invention, as shown in FIG. 2, the transmitting side creates a no-signal state between the scanning lines T, and the transmitting side is configured to be set in the receiving mode during this period.

By doing this, it is possible to detect a message from the receiving side, for example, a transmission stop signal B (-).For example, if a message from the receiving side is a facsimile machine of the CCITT (International Telegraph and Telephone Consultative Committee) Gl standard, For use in the binary control procedure, transfer the flag using a 21 modem, or by using a 2.1'00 ratio carrier in the case of a 3-mm device compatible with the GIT standard. Transmit a message from the receiving side.In any case, the length of the message signal and the period T should be 70 seconds, which is enough time for the receiving device on the transmitter side to operate. If a stop message is received during period T, image transmission is stopped and the line is released.On the other hand, the receiving side sends a stop message for a predetermined period of time and releases the line.When the sending side detects a stop message during period T, If not, ζ2 continues image transmission.

The above-mentioned no-signal period T will be referred to as a "window" hereinafter. The transmitting side does not need to provide this window for each line; for example, in this embodiment, a window is provided for every 10 lines. Since this embodiment targets a facsimile machine of the G2 standard, the maximum time required for 10 lines is 10 to 20 seconds. Therefore, the stop message (300 bps in this example)
The length of the flag transfer is 25 seconds, and the window length is 1 second. An emergency stop button is provided on the receiver side, and when the above button is pressed during reception, it will switch to reception mode (4
) switches to transmission mode and sends a stop message to release the line.

A configuration implementing the above principle is illustrated in FIG. In the figure, the upper part shows the transmitter side,
On the other hand, the lower side shows the receiver side. Also, Fig. 4(a),
Flowcharts of the operating procedures are shown in fbl. Under the control of a control device 1 provided on the transmitter side, a document is sent by a document feed roller 2, and is sequentially read in main and sub-scanning directions (two directions) by a reading device 1', which is temporarily stored in a buffer memory 3. The image information stored in the buffer memory 3 is encoded via the encoding circuit 4, then modulated via the modulator filter 5, and sent to the line 7 via the terminal a of the changeover switch 6 to the receiver side (
- sent. The transmission procedure is shown in FIG. 4 (at).

On the other hand, after the image information transmitted from the line 7 reaches the receiver side, it enters the receiving system via the changeover switch 21 and the d terminal of the changeover switch 8, and then passes through the filter 9 and is demodulated by the demodulator 1o. The demodulated image information is recorded as an image signal by an image signal recording device 12 that is controlled by a control device 11. The reception procedure is shown in FIG. 4(b).

On the other hand, an emergency stop button 13 is provided on the receiver side, and when this emergency button 13 is operated, the control device 11 activates the binary procedure signal transmission system 14 and the changeover switch 8.
Switch to terminal C side.

This binary procedure signal transmission system 14 consists of a modulator 14a and a filter 14b, and transmits the binary procedure signal over the line 7 (2).

On the other hand, the control bag @1 on the sending side stops transferring data to the reading device 1', document feed roller 2, and buffer memory 3 after transmitting image signals for 10 scanning lines (-n lines), and switches the switch. 6 to side b. At this time, the transmitter side changes to the receiving system, and the binary procedure signal receiving system 15
Receive binary procedure signals via. This binary procedure signal receiving system 15 is composed of a filter 15a1, a demodulator 15b, and a flag detection circuit 15c. A flag is transferred from the receiver side, and when it is detected via the detection circuit 15c, the control device 1 switches the switch 6 to the telephone. Side (fold down twice to release the line.

In the above configuration (2), the changeover switch 6 on the transmitter side is normally placed on the a side to transmit images.

- The force control device 1 switches the mode changeover switch 6 to the b side after transmitting, for example, 10 lines of image signals. If flag transfer is not detected from the receiver side during the above-mentioned "window" period T, the control device 1 on the transmitter side again turns the changeover switch to the a side (two-fold, starts the original feed roller 2, and reads the buffer memory by the reading device 1. Start data transfer to 3, 10
Transmit image signals for lines.

On the other hand, on the receiver side (- When an abnormality occurs and, for example, the emergency stop button 13 is pressed, the control device 11 on the receiver side turns the changeover switch to the C side, switches the system to transmission mode, and then transfers the flag for 25 seconds, for example. After transmitting the flag, the control device 11 on the receiver side switches the changeover switch 21 to the telephone side (turning off the line 7). This flag transfer from the receiver side is detected by the detection circuit 15c on the transmitter side. Therefore, for example (7), flag transfer is detected during the "window" period, and the control device 1 on the transmitter side flips the switch 20 to the telephone side and releases the line 7.

In the example described above, the stop message according to the present invention uses the Gl standard binary procedure flag transfer, but the present invention is not limited to this as long as the receiving device on the transmitting side has a reception capability. In addition to the stop message, the request state of the receiver such as an emergency call message can be transferred to the transmitter by simply increasing the number of types of message signals.

As explained above, according to the present invention, a stop period in which no signal is sent is formed between predetermined image scanning lines, and the transmitter side facsimile device is kept in the receiving state during this period. The receiver side can send a signal to the transmitter side to stop transmitting image signals, etc.
This allows the transmitter side and the receiver side to communicate with each other even while transmitting images, making it possible to always transmit normal images.

(8)

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the structure of a facsimile transmission image signal, FIG. 2 is an explanatory diagram showing the communication method according to the present invention, and FIG.
The figure is a block diagram showing the configuration of a transmitting/receiving device that embodies the method of the present invention, and FIGS. '...Reading device 2...
・Document feed roller 3...Buffer memory 4...
Encoding circuit 5/modulator filter 7... line
9... Filter 10... Demodulator AGC
11...Control device 12...Image signal recording device 13
...Emergency stop button 14...Binary procedure signal transmission system 15...Binary procedure signal reception system Patent applicant: Canon Co., Ltd. Agent Patent attorney Takashi Kato

Claims (2)

[Claims] (1) Between predetermined image scanning lines (forms one no-signal period, and during this no-signal period, the transmitter side facsimile machine cannot receive one
A communication method for a facsimile device, characterized in that the facsimile device is set in a state. (2) During the no-signal period (from the two receivers 4ti:j to the transmitter side), a signal is sent to stop image transmission. A communication method for facsimile machines.