JPH07235976A - Automatic answering telephone set - Google Patents

Abstract

PURPOSE:To dispense with the storage of data to judge a busy tone in advance corresponding to an installing area of a device and to accurately judge disconnection of line by surely detecting the busy tone irrespective of the area where the device is installed. CONSTITUTION:A CPU 7 detects the rise of an intermittent signal on a telephone line 5 based on input data from a signal level detection circuit 11 which a recorder 3 is being operated, and measures the period of the rise of the intermittent signal. The CPU 7 compares past three periods measured continuously from the rise time of the signal at every rise of the intermittent signal, respectively, and judges that the period of the rise of the intermittent signal is kept constant when the time difference among the periods is within 100msec. When it is judged that the invariability of the period of the rise is kept for continuous three times, the CPU 7 assumes the intermittent signal on the telephone line 5 as the busy tone, and judges that the line disconnection is performed on the transmission side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an answering machine having a recording device for recording a voice message from a calling side.

[0002]

2. Description of the Related Art In an answering machine of this type, a telephone line is closed and an incoming call is received on the basis of reception of a calling signal transmitted from a telephone exchange over a telephone line. Then, after the response message is sent to the calling side, the voice message from the calling side is recorded by the recording device. When the calling side is on-hook and the line is disconnected in the operating state of the recording device, a busy tone is transmitted from the telephone exchange. When the busy tone is detected, it is determined that the line is disconnected, and the operation of the recording device is stopped.

The busy tone is an intermittent tone signal of a predetermined frequency which is transmitted by the telephone exchange at a constant cycle. Here, as shown in FIG. 2, when the busy tone is transmitted for an on time and the time until the busy tone is stopped and transmitted again is an off time, the total time of the on time and the off time is set. Is the time of one cycle of the busy tone. For example, in Japan, the busy tone has a frequency of 400 Hz and a cycle of 1 second (on time and off time are both 0.5 seconds).

Conventionally, condition data such as frequency, on-time and off-time for determining a busy tone is preset and stored in the memory of the device. Then, when a signal transmitted over the telephone line is received, and if the frequency and period (on time and off time) of the signal correspond to the condition data, it is determined that the signal is a busy tone. Then, the disconnection of the line is determined.

[0005]

However, the frequency and period (on time and off time) of the busy tone are
It depends on the region such as the country. Therefore, in order to make the device usable in all areas, it is necessary to change the condition data stored in the memory of the device according to the installation area of the device, which is very complicated and troublesome. It was a thing.

The present invention has been made to solve the above problems. The purpose is that it is not necessary to store the data for determining the busy tone in advance in correspondence with the area where the device is installed.The busy tone can be reliably detected and the line disconnected regardless of the area where the device is installed. An object is to provide an answering machine that can accurately determine the answer.

[0007]

In order to achieve the above object, in the invention according to claim 1, in an answering machine having a recording device for recording a voice message from a calling side, an operation of the recording device is performed. In this state, a measuring means for measuring the rising cycle of the intermittent signal transmitted over the telephone line, and a judging means for judging whether or not the cycle is constant at each rising edge of the intermittent signal, and being constant. Is provided for a plurality of times in a row, and a determining means for determining a line disconnection is provided.

Further, in the invention as set forth in claim 2, the judging means keeps the cycle constant when the rising cycle of the intermittent signal measured by the measuring means is in the range of 250 msec to 2.5 sec. It is to determine whether or not there is.

Further, in the invention according to claim 3, the judging means compares at least three or more consecutively measured cycles among the rising cycles of the intermittent signal measured by the measuring means. Then, when the time difference between these cycles is within a predetermined time, it is determined that the rising cycle of the intermittent signal is constant.

[0010]

Therefore, according to the first aspect of the invention, when an incoming call arrives, the recording device is activated to record the voice message from the calling side. Then, in the operating state of the recording device, the measuring means measures the rising cycle of the intermittent signal transmitted on the telephone line. Then, the determination means determines whether or not the rising cycle is constant for each rising edge of the intermittent signal. At this time, if it is continuously determined that the cycle is constant a plurality of times, the determining unit determines that the intermittent signal on the telephone line is a busy tone, and determines the line disconnection.

In other words, since the busy tone is transmitted from the telephone exchange at a constant rising cycle, the intermittent signal has a constant rising cycle, and the constant number of times is provided at each rising edge of the intermittent signal. If the determination is made continuously, it is possible to reliably determine that the intermittent signal is a busy tone, not a voice message from the calling side. In addition, since only the rising cycle of the intermittent signal is detected, the busy tone in every region can be reliably detected regardless of the frequency, on-time and off-time, and the line disconnection can be accurately determined. In addition, it is not necessary to store the data for determining the busy tone in advance corresponding to the area where the device is installed.

According to the invention of claim 2, the rising cycle of the intermittent signal measured by the measuring means is 2
If it is not within the range of 50 msec to 2.5 sec, the intermittent signal is considered not to be a busy tone, and it is not determined whether the period is constant. Therefore, even if the intermittent signal has a constant rising cycle, the intermittent signal other than the busy tone, for example, the signal that seems to be a voice message from the calling side can be reliably excluded, and the line disconnection can be determined more accurately. .

Further, according to the third aspect of the invention, among the rising cycles of the intermittent signal measured by the measuring means, at least three or more continuously measured cycles are compared with each other. Then, when the time difference between these cycles is within a predetermined time, it is determined that the rising cycle of the intermittent signal is constant.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the answering machine of the present invention is embodied in a facsimile machine with an answering machine recording function will be described below with reference to the drawings.

As shown in FIG. 1, the facsimile apparatus 1 has a facsimile apparatus main body 2, an attached telephone 4 having a recording device 3, and an NCU (network control unit) 6. Facsimile device body 2
Transmits and receives image data to and from the other side, that is, performs a facsimile operation. The recording device 3 records a voice message from the calling side. The NCU 6 controls the connection with the telephone line 5. Further, the attached telephone 4 is the facsimile device 1
In addition to this, a slave telephone 37 that can be connected to the facsimile apparatus 1 via a cable (not shown) is provided.

Now, the facsimile apparatus main body 2 will be described. A CPU (Central Processing Unit) 7 has a ROM (Read Only Memory) 8 storing programs for controlling the operation of the entire facsimile apparatus main body 2 and the operation of the NCU 6, and a RAM for temporarily storing various information.
(Random access memory) 9 is connected. The modem 10 modulates and demodulates transmitted / received data, and at the same time, a push tone signal (DTM) corresponding to the telephone number of the other party.
F), digital command signal (DCS), digital identification signal (DIS), etc. are generated and detected. Also, the modem 10
A signal level detecting circuit 11 is provided in the signal level detecting circuit 11, and the signal level detecting circuit 11 samples the level of a signal transmitted on the telephone line 5 to obtain digital data C
Output to PU7. Then, the CPU 7 recognizes the signal level on the telephone line 5 based on the input data.

The CPU 7 also has a reading unit 12 for reading an image on a document, a recording unit 13 for printing on a recording sheet based on received image data, and a facsimile operation. Various operation keys (not shown) such as the start key of FIG.

Next, the attached telephone 4 will be described. The attached telephone 4 is provided with a dial CPU 21 for controlling the operation of the entire telephone 4 excluding the recording device 3. A dial key 22 for inputting a telephone number or the like is connected to the dial CPU 21.
A handset 23 is connected to the attached telephone 4.

The recording device 3 is provided with a CPU 24 for controlling the operation of the entire recording device 3, and an attached telephone 4
The CPU 24 controls the operation related to the absence recording. The CPU 24 is connected to the dial CPU 21 via a photo coupler 25, and is also connected to the CPU 7 of the facsimile apparatus main body 2 via a bus (serial bus) 26 for performing serial communication. Serial communication is performed between the CPU 24 of the recording device 3, the dial CPU 21 of the attached telephone 4, and the CPU 7 of the facsimile apparatus main body 2.

DSP (Digital Signal Processor)
27 is for digitally processing the audio signal,
The CP via the address bus 28 and the data bus 29
It is connected to U24. The DSP 27 includes a RAM 30 for storing audio data in an encoded state, and an encoding / decoding circuit 31 for encoding and decoding the audio data.
have. In addition, the CPU 24 of the recording device 3
Various operation keys such as an answering key 32 for setting and canceling an answering machine / FAX mode (described later) and a reproducing key (not shown) for reproducing voice data stored in the RAM 30 are connected.

Next, the NCU 6 will be described. C
The ML relay 36 is provided to selectively connect the telephone line 5 to the modem 10 side of the facsimile apparatus main body 2 and the telephones 4 and 37 side. Then, when the CML relay 36 is switched to the contact a side by the control of the CPU 7 of the facsimile apparatus main body 2, the telephone line 5
Is connected to the telephones 4, 37 side. On the other hand, when the CML relay 36 is switched to the contact b side, the telephone line 5
Is connected to the modem 10 side via the transformer 38.
The CML relay 36 is switched to the contact a side in the communication standby state of the device.

The incoming call detection circuit 39 has a photocoupler, the LED 39a is connected to the contact a side of the CML relay 36, and the phototransistor 39b is connected to the CPU 7 of the facsimile apparatus main body 2. And CPU7
Monitors the on / off state of the phototransistor 39b and detects the presence or absence of a 16 Hz ringing signal transmitted from the telephone exchange on the telephone line 5. The first and second off-hook detection circuits 40 and 41 are connected to the auxiliary telephone 4 or the slave telephone 37, respectively. Then, the off-hook detection circuits 40 and 41 detect the off-hook state of each of the telephones 4 and 37 (including the state of picking up the handset and the operating state of the recording device 3 in the case of the attached telephone 4),
The detection result is output to the CPU 7 of the facsimile apparatus main body 2. The detection result from the first off-hook detection circuit 40 on the side of the attached telephone 4 is the dial CP of the attached telephone 4.
It is also output to U21.

The DC voltage generating circuit 42 is used for the telephones 4, 3
In order to detect the off hook of No. 7, a predetermined current is supplied to each of the telephones 4 and 37, and + 24V is given as an input voltage. That is, when the telephones 4 and 37 are off-hooked, the change in the current supplied to the telephones 4 and 37 is detected by the off-hook detection circuits 40 and 41. Then, based on the detection of the current change by the off-hook detection circuits 40 and 41, the CPU 7 of the facsimile apparatus body 2 and the dial CPU 21 of the attached telephone 4 are detected.
Recognizes an off-hook condition.

The DC voltage generating circuit 42 is connected to the telephones 4 and 37 via the TEL relay 43 and the telephone line 5 is connected.
And is switchably connected. Then, under the control of the CPU 7 of the facsimile apparatus main body 2, when the TEL relay 43 is connected to the contact a side, the telephones 4 and 37 are connected to the telephone line 5 side. On the other hand, when the TEL relay 43 is connected to the contact b side, the telephones 4 and 37 are connected to the DC voltage generating circuit 42 side. In addition, this TEL relay 4
3 is switched to the contact a side in the communication standby state of the device. The transformer 44 is connected to the telephones 4 and 37, and the output side thereof is connected to the modem 10.

As described above, this facsimile machine 1
Then, by operating the absence key 32, the absence / FAX mode is set or released. That is, when a call signal of 16 Hz is transmitted from the telephone exchange when the answering machine / FAX mode is set, the CPU 7 of the facsimile apparatus main body 2
Detects the calling signal via the incoming call detection circuit 39. When the CPU 7 detects the calling signal a predetermined number of times (twice in the present embodiment), the CPU 24 of the recording device 3
An incoming call command signal is sent to the CPU 24 to notify the CPU 24 of the incoming call. Then, the CPU 24 of the recording device 3 operates the DSP 27 to read the data of the voice response message which is prerecorded in the RAM 30 and stored and held therein.
Then, the DSP 27 decodes the data of the voice response message by the encoding / decoding circuit 31 and sends it to the telephone line 5 via the NCU 6.

After that, when the reading of the voice response message is completed, the CPU 24 of the recording device 3 starts the recording operation of the DSP 27 and at the same time sends a recording start signal to the CPU 7 of the facsimile main body 2 to start recording to the CPU 7. Let me know. Then, when the voice message is transmitted from the transmitting side, the DSP 27 encodes the data of the voice message by the encoding / decoding circuit 31, and the R
Store in AM30.

After the recording operation is started, C from the calling side is sent.
When an NG signal is detected or a silent state is continuously detected for a predetermined time (8 seconds in this embodiment), the CPU 7 of the facsimile apparatus main body 2 switches the CML relay 36 from the contact a side to the contact b side. That is, the CPU 7 of the facsimile apparatus main body 2 determines that the calling side is the facsimile apparatus, switches the connection with the telephone line 5 from the telephone 4, 37 side to the modem 10 side, and performs the facsimile operation according to a predetermined facsimile procedure. To start.

Further, in this embodiment, the CPU 7, the ROM 8, the RAM 9, and the signal level detection circuit 11 in the modem 10 of the facsimile apparatus main body 2 constitute a measuring means. That is, as shown in FIG. 2, the CPU 7 of the main body 2 of the facsimile device inputs the recording start signal from the CPU 24 of the recording device 3 and then transmits it on the telephone line 5 based on the input data from the signal level detection circuit 11. Recognize the level of the incoming signal. Then, the CPU 7 determines that the generation of the signal has started, that is, the signal has risen, when the signal level becomes equal to or higher than a predetermined level (-33 dBm in this embodiment). Then, the CPU 7 measures the time from the rising edge of the signal thus determined to the next rising edge, that is, the rising cycle of the intermittent signal.

Further, in the present embodiment, the judgment means is composed of the CPU 7, ROM 8 and RAM 9 of the facsimile apparatus main body 2. That is, C of the facsimile apparatus main body 2
The PU 7 determines, for each rising edge of the intermittent signal, whether or not the measured rising cycle of the intermittent signal is constant. Specifically, for each rising edge of the intermittent signal, the CPU 7 compares the past three consecutively measured periods T1, T2, T3 from the time of the rising edge. That is, the cycle T1 measured this time and the cycle T2 measured last time
And three cycles of the cycle T3 measured two times before are compared with each other. Then, the CPU 7 causes the cycles T1, T
The time difference between T2 and T3 is a predetermined time (100 m in this embodiment).
If it is within the second), it is determined that the rising cycle of the intermittent signal is constant. The CPU 7 determines whether or not the cycle is constant only when the cycle T1 measured this time is within the range of 250 msec to 2.5 sec.

Further, in this embodiment, the CPU 7, the ROM 8 and the RAM 9 of the facsimile apparatus main body 2 constitute a judging means. That is, when the CPU 7 of the facsimile apparatus main body 2 determines that the rising edge of the intermittent signal is constant a plurality of times (three times in this embodiment) as described above, it outputs the intermittent signal. The disconnection is judged by assuming that the tone is a busy tone transmitted from the telephone exchange. In other words, it is determined that the caller is on-hook and disconnected. Then, the CPU 7 sends a recording end command signal to the CPU 24 of the recording device 3, and the CPU 24 of the recording device 3 stops the recording operation of the DSP 27 when the recording end command signal is input.

Next, the operation of the facsimile apparatus with an absence recording function constructed as described above will be described with reference to the timing chart of FIG. 2 and the flow charts of FIGS. The program shown in FIG. 3 and the program shown in FIG. 4 are mutually related and proceed in parallel.

At the time of reception by the facsimile machine with the absence recording function, the facsimile machine main body 2
Under the control of the CPU 7, the operation shown in the flowchart of FIG. 3 is performed. The device is set to the absence / fax mode, and in this state, the CML relay 36 and the TEL relay 43 are switched to the contact a side.

As shown in FIG. 3, when a call signal of 16 Hz is transmitted from the telephone exchange through the telephone line 5 and the call signal is detected twice by the incoming call detection circuit 39, the recording device 3 The serial bus 2 to the CPU 24 of
An incoming call command signal is sent via 6 to notify the incoming call (steps S101 to S102). After that, recording device 3
It is waited for the recording start signal indicating the start of the recording operation to be input from the CPU 24 of the recording device 3 after the transmission of the voice response message by the is completed (step S103).

When a recording start signal is input from the CPU 24 of the recording device 3, the following judgment operation is performed. That is, while the recording device 3 is recording, the CN
Presence / absence of detection of G signal, presence / absence of detection of continuous silence for 8 seconds, status of determination flag set in “line disconnection determination routine” of FIG. 5 described later, and presence / absence of detection of on-hook of recording device 3 And the like are performed (step S1)
04-S107).

The above-mentioned determination operation will be described below in order.
First, in step S104, it is determined whether or not the CNG signal is detected. Here, when the CNG signal is detected, a recording end command signal is sent to the CPU 24 of the recording device 3 (step S108). Then, at the same time when this recording end command signal is transmitted, the CML relay 3
6 is switched to the contact b side, and the telephone line 5 is the modem 1
Then, the facsimile reception operation for receiving the image data from the transmission side is started in accordance with a predetermined facsimile procedure (step S109).

That is, when the CNG signal from the calling side is detected, it is determined that the calling side is a facsimile machine.
Then, after a predetermined facsimile signal such as the transmission of the CED signal and the DIS signal to the transmission side and the reception of the DCS signal from the transmission side is performed, the recording unit 13 is operated and transmitted from the transmission side. The incoming image data is printed on the recording paper. When the facsimile reception operation is completed, the line is disconnected and the communication standby state is restored in the absence / FAX mode.

In step S104, CN
If the G signal is not detected, it is determined whether or not a continuous silent state for 8 seconds has been detected (step S10).
5). Here, when the silent state is detected, the process proceeds to step S108, and as described above, the recording end command signal is sent to the CPU 24 of the recording device 3 and the facsimile receiving operation is started.

That is, the fact that no voice signal or the like is detected for a continuous period of 8 seconds and the voice message is in a silent state means that the transmission of the voice message from the calling side has been completed or there is no voice message. To be judged. When the CNG signal is not detected in step S104, it is determined that the CNG signal is not detected because the facsimile communication is manually performed on the transmitting side, and then the facsimile operation is started.

If no silence is detected in step S105, it is determined whether or not the determination flag is set to "1" in the "line disconnection determination routine" of FIG. 5 described later (step). S106). Here, when the determination flag is set to "1", it is determined that the calling side is on-hook and the line is disconnected, and the recording end command signal is sent to the CPU 24 of the recording device 3 (step S110). Then, in the absence / FAX mode, the communication standby state is restored.

If the determination flag is not set to "1" in step S106, it is determined whether or not the on-hook of the recording device 3 is detected by the first off-hook detection circuit 40 (step). S107).
Here, if the on-hook of the recording device 3 is not detected, the process returns to step S104. When the on-hook of the recording device 3 is detected, the line is disconnected and the standby state is restored. That is, in the present embodiment, the maximum recording time in one recording operation is set to 5 minutes, and when 5 minutes elapse during the recording operation, the recording device 3 is stopped and the on-hook operation is performed. . When the first off-hook detection circuit 40 detects the on-hook of the recording device 3, the determination in step S107 becomes affirmative, the line is disconnected and the standby state is restored.

Although not shown in this flow chart, the CPU of the recording device 3 is used in step S102.
If the handset 23 of the attached telephone 4 or the sub-telephone 37 is off-hook between the time when the incoming call command signal is sent to the terminal 24 to notify the incoming call and the recording operation is stopped in the recording device 3, the recording is performed. The operation of the device 3 is stopped, and the call is ready.

On the other hand, in response to the operation of the main body 2 of the facsimile apparatus, the recording apparatus 3 operates under the control of the CPU 24 as shown in the flowchart of FIG. That is, when an incoming call command signal is input from the CPU 7 of the facsimile apparatus main body 2 (step S201), the DSP
27 is activated to read the data of the voice response message in RAM 30. Then, the data of the voice response message is decoded by the encoding / decoding circuit 31 and transmitted to the calling side via the NCU 6 and the telephone line 5 (step S202).

After that, when the transmission of the voice response message is completed (step S203), the recording operation of the DSP 27 is started (step S204), and a recording start signal is transmitted to the CPU 7 of the facsimile apparatus main body 2 (step). S205). Then, when the voice message is transmitted from the transmitting side, the data of the voice message is encoded by the encoding / decoding circuit 31, and the RAM 30
Be stored in.

Also, before the maximum recording time of 5 minutes has elapsed from the start of the recording operation, the CP of the facsimile apparatus main body 2
When a recording end command signal is input from U7 (step S
206 to S207), the recording operation of the DSP 27 is stopped (step S208), and then the standby state is restored. Also, when 5 minutes have elapsed without inputting the recording end command signal, the process proceeds to step S208, the recording operation of the DSP 27 is stopped, and then the standby state is returned.

Although not shown in this flow chart, after the incoming call command signal is input from the CPU 7 of the facsimile apparatus main body 2 in step S201, D
If the handset 23 or the sub-telephone 37 of the auxiliary telephone 4 is off-hook before the recording operation of the SP 27 is stopped, the operation of the recording device 3 is stopped and the call becomes ready.

Next, the processing operation for setting the state of the determination flag determined in step S106 of the flow chart shown in FIG. 3 will be described. Now,
The flowchart shown in FIG.
2 is a "line disconnection determination routine" for determining a line disconnection executed by the CPU 7. This "line disconnection determination routine" is performed in step S10 of the flowchart shown in FIG.
In step 3, after a recording start signal is input from the CPU 24 of the recording device 3, the recording start signal is executed at regular intervals every predetermined time (5 msec in this embodiment). When the recording start signal is input and the "line disconnection determination routine" is first started, as a default value in the routine, a previous cycle T2, which will be described later, set in the RAM 9 and a cycle T two times before are set.
3, the signal flag, the measurement time t, and the count value N are set to "0". The description of this flowchart will be given with reference to the timing chart of FIG.

When the processing shifts to this routine, first, 5 msec corresponding to the interruption time is added to the measurement time t obtained at the previous interruption, and the result is stored in the RAM 9 as the current measurement time t. It is set (step S301). Next, it is determined whether or not the level of the signal on the telephone line 5 input from the signal level detection circuit 11 is equal to or higher than a predetermined level (-33 dBm in this embodiment) (step S302). Here, the signal level is -33d
If it is not Bm or more, it is considered that the signal is stopped, that is, the off time of the intermittent signal, and R
The signal flag set in the AM 9 is set to "0" (step S303), and the subsequent processing is temporarily terminated.

On the other hand, when the signal level is -33 dBm or higher, it is determined whether or not the signal flag is currently set to "0" (step S304). here,
When the signal flag is not set to "0", it is considered that the signal is currently being generated, that is, the on-time of the intermittent signal, and the subsequent processing is temporarily terminated. If the signal flag is currently set to "0", it is considered that the intermittent signal has been stopped in the previous control cycle, and this intermittent signal is started to be generated and risen. Will be moved to.

Then, in step S305, the signal flag is set to "1", and the previously determined measurement time t is the rising cycle T1 measured this time.
Is set in the RAM 9. Also, the measured time t is cleared to "0". That is, the rising cycle T1 is the time from the previous rising of the intermittent signal to the current rising.

Next, the cycle T1 of this time obtained earlier
Is determined to be within the range of 250 msec to 2.5 sec (step S306). Here, this cycle T1
Is not within the range of 250 msec to 2.5 sec, this intermittent signal is regarded as not a busy tone but another intermittent signal, for example, a voice message from the calling side, and is set in the RAM 9. The count value N is cleared to "0" (step S307). Then, the process proceeds to step S312, where the previous cycle T2 is the cycle T before the previous cycle T2.
3 is set in the RAM 9 and the current cycle T1 is set in the RAM 9 as the previous cycle T2, and the subsequent processing is temporarily terminated.

On the other hand, in step S306, when the current cycle T1 is within the range of 250 msec to 2.5 seconds, the three cycles of the current cycle T1, the previous cycle T2, and the cycle T3 before two times are performed. It is determined whether or not each time difference is within a predetermined time (100 msec in this embodiment) (step S308). That is, the time difference between the current cycle T1 and the previous cycle T2, the time difference between the previous cycle T2 and the cycle T3 two times before, and the time difference between the cycle T1 this time and the cycle T3 two before two are calculated, respectively. It is determined whether the time differences are all within 100 ms. Here, if the time difference between the three cycles T1, T2, T3 is not within 100 msec, it is determined that the rising cycle of the intermittent signal is not constant, the process proceeds to step 307, and the count value N is "0". Will be cleared.

When the time difference between the three cycles T1, T2 and T3 is within 100 msec, it is determined that the rising cycle of the intermittent signal is constant and the previous count value N
Is incremented by 1, and the result is the current count value N
Is set as (step S309). Next, the count value N set this time is a predetermined value (“3” in this embodiment).
It is determined whether or not the above has been reached (step S31).
0). If the count value N is not "3" or more, the process proceeds to step S312 and the previous cycle T
2 is set as the previous cycle T3, the current cycle T1 is set as the previous cycle T2, and the subsequent processing is once ended.

On the other hand, when the count value N is "3" or more, that is, when it is determined that the rising period of the intermittent signal is constant three times in a row, the intermittent signal is sent from the telephone exchange. It is considered to be a busy tone transmitted, and it is determined that the caller side is on-hook and the line is disconnected, and the process proceeds to step 311. And
In step 311, the determination flag indicating the line disconnection set in the RAM 9 is set to "1". After that, the process is temporarily terminated after shifting to the step S312.

In this way, the line disconnection on the calling side is determined, and the determination flag is set to "1". Then, in this "line disconnection determination routine", the determination flag is "1".
3 is set, it is determined that the determination flag is set to "1" in step S106 of the flowchart shown in FIG. 3, and a recording end command signal is sent to the CPU 24 of the recording device 3 to set the recording device. The operation of 3 is stopped.

As described above, in this embodiment, the recording device 3
In this operating state, the rising edge of the intermittent signal transmitted on the telephone line 5 is detected and the rising cycle is measured. Then, for each rising edge of the intermittent signal, the past three consecutively measured cycles are compared from the time of the rising edge, and if the time difference between these cycles is within 100 msec, the rising cycle of the intermittent signal is constant. It is determined that When it is determined that the rising cycle is constant three times in a row, the intermittent signal on the telephone line 5 is regarded as a busy tone transmitted from the telephone exchange, and the line is disconnected at the originating side. I am determined to have been done.

That is, the busy tone is transmitted from the telephone exchange in a regular and constant rising cycle, even if the frequency, the on-time and the off-time greatly differ depending on the region such as the country. Therefore, if the rising cycle of the intermittent signal on the telephone line 5 is constant, and if it is determined that the constant cycle is repeated a plurality of times at each rising edge of the intermittent signal, the intermittent signal is the voice from the calling side. It can be surely judged that it is a busy tone, not a message or the like. In addition, since only the rising cycle of the intermittent signal is detected, the busy tone in every region can be detected reliably regardless of its frequency, on-time and off-time, and the line disconnection can be accurately determined. . As a result, the operation of the recording device 3 can be reliably stopped when the line is disconnected on the calling side. Further, it is possible to save the trouble of pre-storing the data for determining the busy tone in correspondence with the area where the device is installed.

In this embodiment, the line disconnection is determined when it is determined that the rising cycle is constant three times in succession. Instead of being able to determine the line break faster,
The determination result may be slightly unreliable. Further, when the number of times is 4, the reliability of the line disconnection determination result is improved, but the time until the determination becomes long. Therefore, considering the reliability of the determination result of line disconnection and the time until the determination, it is most desirable to set the number of times to three. In addition, in the present embodiment, it is determined whether or not the cycle is constant by comparing each of the three cycles measured continuously. It is most desirable to compare the two cycles.

Further, in this embodiment, when the rising cycle of the intermittent signal measured this time is not within the range of 250 msec to 2.5 seconds, the intermittent signal is regarded as not a busy tone and the cycle is constant. It does not judge whether or not. Therefore, even if the intermittent signal has a constant rising cycle, it is possible to reliably exclude the intermittent signal other than the busy tone, for example, the signal that seems to be a voice message from the calling side, and to judge the line disconnection more accurately. be able to.

The present invention is not limited to the above embodiments, but can be embodied in the following modes, for example. (1) Step S of "line disconnection determination routine" shown in FIG.
In 310, when the count value N becomes "2" or "4" or more, the determination flag should be set to "1". That is, when it is determined that the rising cycle of the intermittent signal is constant twice or four times or more consecutively, the line disconnection is determined. Further, the count value N for determining the line disconnection may be arbitrarily changed by the operator by operating a predetermined key.

(2) "Line disconnection determination routine" shown in FIG.
In step S308, when determining whether or not the rising cycle is constant, four or more continuously measured cycles are compared with each other. Also, the time difference in determining whether or not those cycles are constant is 10
Change to a time difference within a predetermined time other than 0 ms, for example within 120 ms, within 80 ms, or within 50 ms.

(3) "Line disconnection determination routine" shown in FIG.
In step S306, the time range of 250 ms to 2.5 seconds, which is the allowable time range of the current cycle T1, is changed.

(4) "Line disconnection determination routine" shown in FIG.
In step S302, change the signal level for determining whether the intermittent signal is on time or off time to a level other than -33 dBm.

(5) DSP for the signal level on the telephone line 5
It should be detected by 27. (6) The present invention is embodied in a simple answering machine having no facsimile function.

The technical ideas other than the claims which can be understood from the above-described embodiments will be described below together with their effects. (1) The answering machine according to claim 1, wherein the determining means determines the line disconnection when it is determined that the rising edge of the intermittent signal is constant three times in a row.

As described above, it is most desirable to set the number of times to three in consideration of the reliability of the determination result of the line disconnection and the time until the determination. (2) The answering machine according to claim 1, further comprising a control means for controlling the operation of the recording device 3 to be stopped when a line disconnection is determined.

In this structure, the control means is composed of the CPU 7, the ROM 8 and the RAM 9 of the facsimile apparatus main body 2 and the CPU 24 of the recording apparatus 3. With this configuration, the operation of the recording device 3 can be reliably stopped when the line is disconnected on the calling side.

[0067]

As described above in detail, according to the present invention,
It is not necessary to store the data for determining the busy tone in advance in correspondence with the area where the device is installed, and regardless of the area installed, the busy tone can be reliably detected and the line disconnection can be accurately determined. It has an excellent effect of being able to do.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment in which an answering machine of the present invention is embodied in a facsimile machine with an answering machine recording function.

FIG. 2 is a timing chart showing the level of a signal on a telephone line detected by a signal level detection circuit.

FIG. 3 is a flowchart showing an operation of the facsimile apparatus main body at the time of reception by the facsimile apparatus.

FIG. 4 is a flowchart showing an operation of the recording device when the facsimile device receives it.

FIG. 5 is a flowchart illustrating a “line disconnection determination routine” executed by the CPU of the facsimile apparatus main body for determining a line disconnection.

[Explanation of symbols]

3 ... Recording device, 4 ... Attached telephone, 5 ... Telephone line, 7 ... CPU constituting measuring means, judging means and judging means, 8 ...
ROM constituting measurement means, determination means, and determination means, 9
... a RAM constituting the measuring means, the judging means, and the judging means,
11 ... Signal level detection circuit constituting measuring means, 27 ...
DSP, 32 ... Answer key, T1, T2, T3 ... Cycle.

Claims (3)

[Claims] 1. An answering machine having a recording device for recording a voice message from a calling side, in an operating state of the recording device, measuring means for measuring a rising cycle of an intermittent signal transmitted over a telephone line. And a judging means for judging whether or not the cycle is constant at each rising edge of the intermittent signal, and a judging means for judging the line disconnection when the constant is judged a plurality of times consecutively. Answering machine. 2. The determination means has a rising cycle of the intermittent signal measured by the measurement means of 250 msec to 2.5 msec.
The answering machine according to claim 1, wherein the answering machine determines whether or not the cycle is constant when it is within the range of seconds. 3. The determination means compares at least three or more consecutively measured periods among the rising periods of the intermittent signals measured by the measuring means,
The answering machine according to claim 1 or 2, wherein when the time difference between these cycles is within a predetermined time, it is determined that the rising cycle of the intermittent signal is constant.