JPH0422067B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile device, and more particularly, a first initial identification signal having a first frequency component, a second initial identification signal having the first frequency component and a second frequency component. a facsimile device that identifies a third initial identification signal that has the first frequency component and the second frequency component and has a generation pattern of the two frequency components that is different from the second initial identification signal. It is related to.

When image transmission is performed using a facsimile apparatus having a conventional transmission method conforming to CCITT Recommendation T.3 and a redundancy suppressed analog high-speed transmission (hereinafter referred to as analog high-speed transmission) mode, there are the following drawbacks.

Figure 1 shows the above group 2 (hereinafter referred to as G2).
This figure shows the signal exchange in the pre-transmission procedure when transmitting an image using a facsimile machine. Here, it is assumed that the facsimile device on the receiving side is a facsimile device (G2+G3) that has a transmission mode that conforms to CCITT Recommendations T.3 and T.4, and does not have a high-speed transmission mode.

In FIG. 1, when the line is acquired in a known manner, the receiving facsimile machine sends a series of initial identification signals (CED1, preamble signal 2,
It is composed of NSF, CSI, DIS3, and GI24, and these comply with CCITT's T.30 recommendation. ) will be sent. The sending facsimile device sends an identification signal GI indicating the group G2 to which the receiving device belongs.
2, a tonal signal SGC (Skip Group
Command) 5 is sent. Since the receiving facsimile device does not have an analog high-speed transmission mode,
Without sending SCFR (Skip Confirmation) corresponding to SGC, GI24, preamble signal 2 again,
Sends NSF/CSI/DIS3. In response to this GI2, the sending facsimile sends out a tonal signal GC26 indicating that transmission is to be performed in a transmission mode conforming to the T.3 recommendation, and sends out a transmission line adjustment signal LCS7 and a phase signal PHS8 to the line. After receiving PHS8, the facsimile receiver sends a reception preparation completion confirmation signal CFR9 to the line. Thereafter, the image is transmitted using a transmission method that complies with CCITT Recommendation T.3.

As described above, the conventional facsimile apparatus which also has analog high-speed transmission conforming to T.3 has to transmit both SGC5 and GC26 twice, regardless of the group of the receiving side apparatus.

In addition, even if the receiving facsimile device has a transmission method that conforms to CCITT Recommendation T.2 or T.4 (it does not have an analog high-speed transmission method), the first GI2
Sending the SGC signal for the signal and sending the GC2 signal for the second GI2 signal is the same as above, but the point is that the pre-procedure takes longer.
Another problem was that this SGC signal increased the possibility that the facsimile machine on the receiving side would malfunction.

The present invention has been made in view of the above-mentioned problems, and is capable of quickly detecting three types of initial identification signals having a first frequency component or a first frequency component and a second frequency component without erroneously detecting them. The purpose is to provide a facsimile device that can perform

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

Facsimile machines that use a transmission method that complies with CCITT Recommendation T.3 and a redundancy suppressed analog high-speed transmission method usually have only a simple tonal counter. In the present invention, by using this tonal counter, the initial identification signal from the other receiver is
Identification signal GI2, group 1 or 2 identification signal (GI1/2), or a binary signal indicating that the other receiver has G3 function and can perform analog high-speed transmission, and thereby The configuration is such that it is determined whether to send out the GC2 signal or the SGC signal.

These three types of signals will be explained below.

Signal GI2 is a group 2 identification signal, which is sent from the receiving side and indicates that the device is in receiving mode and that at least 1 A-4 original is in group 2 mode.
Indicates that the page can be received. Figure 2 shows the format of the GI2 signal. as shown
The GI signal is a 1850Hz signal with a length of 1.5 seconds and an interval of 3.0 seconds.

In addition, the signal GI1/2 is a group 1 or 2 identification signal and indicates that the device is in reception mode and that at least A-2 is in group 1 or group 2 mode.
4 Indicates that one page of the original can be received. G.I.
The format of the 1/2 signal is shown in FIG. As shown in the figure, GI1/2 is 1650Hz1.5 seconds, 1850Hz0.75
It consists of seconds, and the interval is 3.0 seconds. Normally, the tolerance for both GI2 and GI1/2 signals is set to approximately ±15% in timing and ±6Hz in frequency.

Next, the aforementioned binary signal will be described.

When the other party's receiver also has the G3 function, the first initial identification signal sent to the line by the receiver is not a tonal signal but a binary signal. These are shown with reference numeral 3 in Figure 1, and are digital identification signals.
DIS, called station terminal identification signal CSI, non-standard equipment signal
These signals are composed of NSF etc.
At 300bps, information "0" is 1850Hz, information "1" is
It is FSK modulated at 1650Hz and sent to the line. Here, DIS is a signal indicating that the called device has a standard CCITT function, and CSI is an optional signal, which is used to confirm the called station by the number assigned to the called station or the telephone number, etc. The NSF signal is an optional signal used to identify specific user requests that are outside the scope of the T-series recommendations.

In addition, a preamble signal is always sent to the line for 1 ^sec (±15%) with the above binary signal.
This preamble signal is a signal that ensures that all components of the communication channel are properly adjusted so that subsequent data can be transmitted without loss. The format is a series of "01111110", "0" is FSK at 1850Hz and "1" is FSK at 1650Hz.
It is modulated and sent out on the line.

FIG. 4 shows a block diagram of an embodiment of a circuit for receiving tonal signals according to the present invention.

In FIG. 5, what is indicated by the reference numeral 10 is
This is a network control unit (hereinafter referred to as NCU). The signal line 10a is a telephone line, and the symbol 12 is an equalizer having a function of correcting attenuation distortion, group delay distortion, etc. of the telephone line.

The tonal signal sent from the other party's facsimile machine is attenuated by the telephone line, which is the transmission medium, before reaching the facsimile machine on the other side. Therefore, since the signal on the signal line 12a that has passed through the NCU 10 and equalizer 12 is an attenuated signal, an amplifier 14 is provided to amplify this signal. The amplified signal here is transmitted to the signal line 14
The signal is output to the binarization circuit 16 and the signal presence/absence detection circuit 20 via the signal a. This binarization circuit 16 is a circuit that binarizes an input signal with respect to a certain reference voltage, and the binarized tonal signal is sent to a tonal counter circuit 18 via a signal line 16a. It is being output. The tonal counter circuit 18 measures the time of one cycle of the input tonal signal, and the frequency of the tonal signal can be recognized from the time of one cycle.

The signal presence/absence detection circuit 20 is composed of an integrating circuit, a comparator, etc., and receives the output signal of the amplifier 14 described above, and uses this signal to enable the facsimile machine on this side to receive a signal from the facsimile machine on the other side. A detection circuit that detects whether or not
With respect to the control circuit 22, if the facsimile device on this side is currently receiving a signal from the facsimile device on the other side, it outputs a high level to the signal line 20a, and the facsimile device on this side is currently receiving a signal from the facsimile device on the other side. If no signal is received from the signal line 20a, a low level is output to the signal line 20a.

The outputs of the tonal counter circuit 18 and the signal presence detection circuit 20 are connected to a control circuit 22. The control circuit 22 is connected to a tonal data table 24 made up of a ROM or the like and a memory 26 made up of a RAM or the like, and performs control described later by referring to these. The control circuit 22 also connects the GI2,
A G2 mode signal sending circuit 30 that sends out each signal of GC2, LCS, and PHS corresponding to GI1/2, and the above-mentioned binary signal NSF,
It is connected to an SGS signal sending circuit 32 that sends out SGC signals corresponding to CSI and DIS. Further, the control circuit 22 is connected to a timer 28 by signal lines 28a and 28b.

Next, FIG. 5 shows the above-mentioned tonal counter circuit 1.
A specific example of No. 8 will be shown in detail.

In FIG. 5, what is indicated by the reference numeral 34 is:
This is a timing clock used to measure the time of one period of a tonal signal. In this embodiment, two outputs of the timing clock 34 are provided, and a 61920 Hz frequency clock is output to the signal line 34a, and a 30960 Hz frequency clock is output to the signal line 34b.

The D flip-flop 36 receives the inverted output (signal line 36b) signal level of the D flip-flop 32 itself when the input level from the binarization circuit 16 sent via the signal line 16a changes from "0" to "1". It is set or reset depending on whether it is "1" or "0". Therefore, the non-inverted output (signal line 36a) of the D flip-flop 36 is at level "1" when set, and at level "0" when reset.
becomes. The inverted output (signal line 36b) of the flip-flop 36 has an opposite relationship to the output 36a,
When the signal line 36a is at the level "0", the signal line 36b is at the level "1", and when the signal line 36a is at the level "1", the signal line 36b is at the level "0". Further, when the level of the signal line 22a is "1", the flip-flop 36 is reset.

Further, the reference numeral 38 is also a D flip-flop, which is set when the input level from the inverted output (signal line 36b) of the D flip-flop 36 changes from "0" to "1", and the level of the signal line 46a is set. Set when it is "1". Similarly, the flip-flop 38 is set when the level of the signal line 22a is "1".
The signal line 38a becomes level "0" when the flip-flop 38 is set, and becomes level "1" when it is reset.

A counter 40 counts the number of timing clocks input from the signal line 34a only while the input level from the signal line 36a of the flip-flop 36 is "1".
Output the count value from a to 40h. Further, the output of the counter 40 is cleared when the level of the signal line 48a becomes "0". That is, the signal line 40
Values a to 40h are level "0".

The counter 42 also counts the number of timing clocks input from the signal line 34b only while the input level from the signal line 38a of the flip-flop 38 is "1". When 256 timing clocks are input from the signal line 42a,
Outputs level "1" for one clock. The counter 42 is cleared when the level of the signal line 50a becomes "0". In addition, here, what is indicated by the reference numeral 44 is an inverter circuit, 46 is a NOR circuit, and 4 is an inverter circuit.
8 is a NOR circuit, 50 is an inverter circuit, and 52 is an inverter circuit.

Next, the operation of the tonal counter shown in FIG. 5 will be explained using the timing chart shown in FIG. 6.

When a clear pulse p is generated on the signal line 22a,
Flip-flops 36 and 38 are reset.
As a result, the signal line 36a becomes level "0", the signal line 36b becomes level "1", the signal line 38a becomes level "1", and the signal line 52a becomes level "0".

Binarized tonal signal, that is, signal line 16
When a changes from level "0" to level "1" at the time point q, the signal level of signal line 36b is "1", so flip-flop 36 is set. As a result, the signal line 36a becomes level "1" and the signal line 36b becomes level "0".

At the point in time when the signal line 16a is indicated by r, the level is "0".
When the level changes from 1 to 1, the flip-flop 36 is reset because the signal level of the signal line 36b is 0. As a result, the signal line 36a
is at the level "0", and the signal line 32b is at the level "1". At this time, the signal line 36b changes from level "0" to level "1" (shown at s), and the flip-flop 34 is set. As a result, signal line 38
a is level “0” and signal line 52a is level “1”
becomes.

Next, FIG. 7 shows a memory map of the tonal data table shown in FIG. 4, 24. In the figure, each data corresponds to 8 bits for addresses 0 to 9.

Further, FIG. 8 shows a memory map of the memory 26 of FIG. 4. In Figure 8, CNT462,
CNT110, CNT165, CNT185, CNT
A 2-byte memory area is reserved in 210. Then, count the 462Hz signal, 1100Hz signal, 1650Hz signal, 1850Hz signal, and 2100Hz signal, respectively.

9a to 9c illustrate the control flow of the control circuit of FIG. 4. However, in FIGS. 9a to 9c, flows labeled with the same alphabet indicate that they are connected at that location.

In step 54 of FIG. 9a, the contents of the B register are set to 0. This is set to 0 as an initial value in order to check whether a preamble signal has been received before when the GI2 signal is received.

In step 56, it is determined for 30 ms continuously whether the signal line 20a, that is, the output of the signal presence/absence detection circuit 20, is at a high level, that is, whether a signal is coming from the other party's facsimile receiver. If there is no signal from the other party's facsimile receiver, proceed to step 58; if there is a signal from the other party's facsimile receiver, proceed to step 62.
Proceed to.

In step 58, it is determined whether 35 seconds have elapsed since the line was connected to the facsimile machine. If 35 seconds have not elapsed, the process returns to step 56; if 35 seconds have elapsed, the process ends as in step 60, resulting in an error termination.

In step 62, a pulse is generated on signal line 28a to start a one second timer.

In step 64, CNT in memory 26 is
Set -310 to 165. Here, the contents of the CNT 165 are incremented by one every time a 1650 Hz signal is received for two cycles. That is,
It takes 1650Hz before the content of CNT165 becomes 0.
It is necessary to receive the signal for 0.38 seconds (1/1650 x 2 x 310 ≒ 0.38) using the integrated type.

In the following step 66, the memory 26 is
Set -463 to CNT185. Here, 1850
Every time the Hz signal is received for two cycles, the contents of the CNT 185 are incremented by one. That is, CNT1
In order for the contents of 85 to become 0, it is necessary to receive a 1850 Hz signal in an integrated manner for 0.50 seconds (1/1850×2×463≈0.50).

In step 68, it is determined whether the signal line 20a is at a high level, that is, whether a signal is coming from the other party's facsimile receiver. If there is no signal from the other party's facsimile receiver,
The process returns to step 56, and if a signal is received from the other party's facsimile receiver, the process proceeds to step 70.

In step 70, a pulse is generated on the signal line 22a, and the flip-flops 36, 38 and counters 40, 4 of the tonal counter circuit of FIG.
Clear 2.

In step 72, it is determined whether the signal line 52a, that is, the output of the tonal counter circuit 18, is at a high level, that is, whether the measurement of one period of time has been completed. Measuring the time of one cycle (actually,
Step 72 is repeated until the number of clocks during one cycle is counted using a certain fixed clock, and then the process proceeds to step 74.

In step 74, TONPTR is set to 4, and in step 76, CNTPTR is set to 2.
Set to .

In step 78, the signal lines 40a to 40
Input h, that is, the number of clocks during one cycle. This clock frequency is 61920Hz.

In FIG. 9b from step 80,
Enter the contents of TONPTR. In step 82, the signal line 4 inputted in step 78 is
0a to 40h and entered in step 80.
Compare the value with the contents of TONPTR. If the contents of TONPTR are less than but equal to the values on signal lines 40a-40h, the process proceeds to step 98; if the contents of TONPTR is greater than the values on signal lines 40a-40h, the process proceeds to step 84.

At step 84, TONPTR is incremented by one, and at step 86, the contents of TONPTR are input.

In step 88, similarly to step 82, the signal line 40a inputted in step 78 is
~40h and entered in step 86
Compare the value with the contents of TONPTR. If the contents of TONPTR are smaller than or equal to the values of signal lines 40a to 40h, proceed to step 90,
If the content of is greater than the value of signal lines 40a-40h, the process advances to step 92.

In step 90, the contents of CNTPTR are
That is, the content of the counter corresponding to the frequency of the input signal is increased by one.

In step 92, it is determined whether CNTPTR is 3. If CNTPTR is 3, the process proceeds to step 98; if CNTPTR is not 3, the process proceeds to step 94.

In step 94, TONPTR is increased by 1, and in step 96, CNTPTR is increased by 1.
Increase by one.

Steps 68 to 96 have been described above. In steps 68 to 96, the frequency is determined by measuring the time of one cycle, and when this frequency is between 1588 Hz and 1720 Hz, the contents of CNT 165 are incremented by 1, and between 1769 Hz and 1935 Hz. When , CNT
Increment the contents of 185 by one.

In step 98, CNT165 or
The content of CNT185 has become positive, that is, it is an integration type, 1650Hz for 0.38 seconds or 1850Hz for 0.5 seconds.
It is determined whether the signal is received in seconds. Integrating type, 1650Hz
If 0.38 seconds or 1850Hz is not received for 0.5 seconds, proceed to step 100 and use the integration type to receive 1650Hz for 0.38 seconds.
If the signal is received for 0.5 seconds or 1850 Hz, the process proceeds to step 108.

At step 100, it is determined whether the signal line 28b is at level 1, that is, whether one second starting at step 62 has elapsed. If one second has not elapsed, the process proceeds to step 68; if one second has elapsed, the process proceeds to step 102.

In step 102, as in step 58, it is determined whether 35 seconds have elapsed. If 35 seconds have not elapsed, the process proceeds to step 104; if 35 seconds have elapsed, the process ends with an error as in step 106.

In step 104, it is determined whether the signal line 20a is at a low level for 20 ms continuously, that is, whether there is no signal from the other party's facsimile receiver. If there is a signal from the other party's facsimile receiver, proceed to step 102; if no signal is received from the other party's facsimile receiver, proceed to step 102.
Proceed to step 56.

In step 108, check whether the content of CNT165 is positive, that is, 1650Hz is 0.38 in the integrated type.
It is determined whether the signal is received in seconds. If the content of CNT 165 is not positive, the content of CNT 185 is positive. In this case, 1850Hz is integrated and 0.5
It recognizes that it has received the GI2 signal. If the content of CNT165 is positive, the process advances to step 120.

In step 110, the GI2 signal is currently being received, but it is determined whether a preamble signal has been received before that. If the contents of the B register are not 0, that is, a preamble signal has been received before then, the process proceeds to step 118. If the content of the B register is 0, ie, no preamble signal has been previously received, the process proceeds to step 112.

In step 112, a command pulse is generated on the signal line 32a, and the SGC signal sending circuit 32 is
Send the SGC signal to the line.

In step 114, it is determined whether the signal sent to the receiving side after sending the SGC signal to the line is a GI2 signal or an SCFR signal.

The signal sent to the other receiver in G2 mode is
If it is an SCFR signal, the image is transmitted using a known redundancy suppression analog high-speed transmission method (step 116). The above operation is shown in FIG. If the signal from the other receiver is a GI2 signal, the process advances to step 118.

In step 118, a command pulse is generated on the signal line 30a, and the G2 mode signal sending circuit 30
GC2 signal, LCS signal, and PHS signal are sent to the line. These operations are shown in FIG.

In step 120, 404 is added to the contents of CNT 185. Here, if pure 1650Hz is being received, in step 120
Even if 404 is added to the contents of CNT185, CNT1
The content of 85 is -59. However, if the preamble is being received, while receiving 1650Hz for 0.38 seconds,
Since 1850Hz is also received for approximately 0.13 seconds (0.38 x 1/3 = 0.13), the content of CNT185 is also positive.

In step 122, it is determined whether the content of CNT 185 is positive. If the content of CNT 185 is positive, it is recognized that a preamble has been received, and 1 is placed in the B register in step 124. When the content of CNT185 is not positive,
Proceed to step 126.

In step 126, the memory 26 is
Set -278 to CNT185. Here, 1850
Every time the Hz signal is received for two cycles, the contents of the CNT 185 are incremented by one. That is, CNT1
In order for the contents of 85 to become 0, it is necessary to receive a 1850 Hz signal in an integrated manner for 0.30 seconds (1/1850×2×278≈0.30). Based on the judgment in step 122, the process proceeds to step 126 when a pure 1650 Hz signal is received, and after that, the signal being sent from the other party's receiver does not cut off and the 1850 Hz signal is transmitted.
If received for 0.30 seconds, it is recognized as a GI1/2 signal.

In step 128, it is determined whether the signal line 20a is at a high level, that is, whether a signal is being received from the other party's facsimile receiver. If a signal is coming from the other party's facsimile receiver, the process advances to step 130. If there is no signal from the other party's facsimile receiver, proceed to step 5.
Proceed to step 6. If you proceed to step 56,
After receiving a 1650Hz signal for 0.38 seconds, the signal from the other party's facsimile receiver cuts out at 1850Hz.
This is the case when the GI1 signal is not received, and it is recognized that the GI1 signal has been received.

In step 130, a pulse is generated on the signal line 22a to clear the flip-flop counter of the tonal counter circuit of FIG.

In step 132, it is determined whether the signal line 52a, which is the output of the tonal counter circuit 18, is at a high level, that is, whether the measurement of one period of time has been completed. Step 1 continues until the time measurement for one cycle (actually, counting the number of clocks during one cycle using a certain clock) is completed.
After repeating step 32, the process advances to step 134.

In step 134, CNTPTR is set to 3, and in step 136, TONPTR is set to 3.
Set to 6.

In step 138, the signal lines 40a to 4
Input 0h, that is, the number of clocks during one cycle.

In step 140, the contents of TONPTR are input. In step 142, the signal lines 40a to 40h inputted in step 138 are
The value is compared with the contents of TONPTR input in step 140. When the contents of TONPTR are smaller than or equal to the values of signal lines 40a to 40h,
The process proceeds to step 152, and if the contents of TONPTR are greater than the values on the signal lines 40a-40h, the process proceeds to step 144.

In step 144, TONPTR is increased by one, and in step 146, TONPTR is increased by one.
Enter the contents.

In step 148, the signal lines 40a to 40b inputted in step 138 are
The value is compared with the contents of TONPTR input in step 46. The contents of TONPTR are signal lines 40a to 40
If it is less than or equal to the value of h, step 15
0, and the contents of TONPTR are transferred to signal lines 40a to 4.
If the value is greater than 0h, the process advances to step 152.

In step 150, the contents of COTPTR, that is, the contents of CNT 185, are incremented by one.

In step 152, it is determined whether the content of CNT185 has become positive, that is, 1850 in the cumulative type.
It is determined whether a Hz signal is received for 0.30 seconds. If the integration type is receiving a 1850Hz signal for 0.30 seconds,
This is a case in which a 1850Hz signal is received following a 1650Hz signal, and it is recognized that a GI1/2 signal has been received, and the process proceeds to step 154. If the integration type is not receiving a 1850 Hz signal, proceed to step 128.

In step 154, a command pulse is generated on the signal line 30a, and as in step 118, the G2 mode signal transmission circuit 30 sends the GC2 signal, LCS signal, and PHS signal to the line. The above operations are shown in FIGS. 12, 13, and 14.

The above-described operation will be summarized below with reference to FIGS. 10 to 14 again.

First, if the other party's facsimile receiver is a G2 group facsimile device as shown in FIG. Sends tonal signals and SGC signals for analog high-speed transmission methods. Here, if the other party's facsimile receiver has the function of transmitting images using the redundancy suppression analog high-speed transmission method described above, the receiver will
After recognizing the SGC signal, sends the SCFR signal to the line,
The previous step ends. After this, analog high-speed transmission can be performed.

On the other hand, as shown in FIG. 11, if the other party's facsimile receiver has the G2 mode but does not have the function of transmitting images using the redundancy suppression method analog high-speed transmission method, the receiver , sends the group 2 identification signal to the line again. The transmitter responds to the second Group 2 identification signal GI2 that the receiver sends out to the line using CCITT Recommendation T.
A tonal signal for carrying out the transmission method conforming to No. 3, that is, a group 2 command signal GC2, is sent to the line. After that, the transmitter sends a transmission line adjustment signal
Sends LCS and phase signal PHS to the line. After receiving the PHS signal, the facsimile receiver sends a reception preparation confirmation signal CFR2 to the line, and the previous procedure ends. Thereafter, the image can be transmitted electronically using a transmission method that complies with CCITT Recommendation T.3.

In addition, as shown in FIGS. 12 to 14, the other party's facsimile device is in G1+G2 (FIG. 12) mode, G2+G3 mode (FIG. 13), and G1+G2+G3 (FIG. 14) mode, which does not have analog high-speed transmission.
If the device has a mode, the first group 2 identification signal GI sent from the receiver to the transmitter.
2, it has now become possible to send a tonal signal for carrying out a transmission method conforming to CCITT Recommendation T.3, that is, a group 2 command signal GC2, to the line. This makes it possible to shorten the time required for the pre-procedure and further reduce the possibility of malfunction of the facsimile receiver.

In addition to the above embodiments, a display device may be provided to display the transmission mode of the receiving facsimile device identified as described above. As a result, if the other party's facsimile receiver does not have analog high-speed transmission using the redundancy suppression method described above, the group of the other party's facsimile receivers can be displayed on the transmitter side, and the operator on the transmitter side can If the other party's receiver recognizes this display as a G2+G3 group or G1+G2+G3 group, and there is also a G3 device on the transmitter side, stop transmitting the document in G2 mode and make the call again. It is also possible to switch to electronic transmission of originals in G3 mode.

As described above, according to the present invention, the frequency of a received signal is detected, and the detected first frequency and second frequency are
The time of the frequency is determined, and based on the determination result, it is determined which of the three initial identification signals has been received, so the three initial identification signals each having a common frequency component are detected by frequency detection. In the case of identification, the received initial identification signal can be quickly identified without erroneous detection.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining the pre-procedures of a conventional facsimile device, FIGS. 2 and 3 are explanatory diagrams of an initial identification signal used in the facsimile device, and FIG. 4 is a block diagram of the control system of the facsimile apparatus of the present invention, FIG. 5 is a more detailed circuit diagram of FIG. 4, and FIG. 6 is an explanation of the operation of the circuit of FIG. 5. FIG. 7 is an explanatory diagram showing a memory map of the tonal data table in FIG. 4, FIG. 8 is an explanatory diagram showing a memory map of the memory in FIG. 4, and FIGS. Flowchart diagram showing the operation of the control circuit of FIG.
FIG. 14 is an explanatory diagram illustrating the pre-transmission procedure of the facsimile apparatus of the present invention. 10... NCU, 12... Equalizer, 14... Amplifier, 16... Binarization circuit, 18... Tonal counter circuit, 20... Signal presence detection circuit, 22...
...control circuit, 24...tonal data table,
26...Memory, 28...Timer, 30...G
2 signal sending circuit, 32...SGC signal sending circuit.

Claims (1)

[Scope of Claims] 1. A first initial identification signal having a first frequency component, a second initial identification signal having the first frequency component and a second frequency component, the first frequency component and the above. In a facsimile device for identifying a third initial identification signal having a second frequency component and a generation pattern of the two frequency components different from the second initial identification signal, means for detecting the frequency of the received signal; The time between the first frequency and the second frequency detected by the detection means is determined, and the first initial identification signal and the second frequency are determined based on the determination result.
A facsimile apparatus comprising means for identifying the initial identification signal and the third initial identification signal.