JPH04336756A - Facsimile device with voice response function - Google Patents

Abstract

PURPOSE:To detect a CNG signal while transmitting a response signal and to provide the response signal whose specific frequency component can be left as much as possible, as to a facsimile device performing a voice response to an incoming call, detecting the CNG signal of the facsimile device on the calling side and automatically switching to a facsimile receiving side. CONSTITUTION:A filter means 10 is provided between a telephone line interface circuit 5 and response sound signal transmission circuit 2 generating the response signal. Since the filter means 10 is changed over between a notch filter characteristic and a flat characteristic at a prescribed cycle during the generation period of the response signal, the specific frequency component of the response signal to be transmitted to a telephone line 6 is intermittently removed at the prescribed cycle. Accordingly, by detecting the consecutive specific frequency component beyond the consecutive time of the specific frequency component, a CNG detection circuit 7 detecting the CNG signal from the telephone line can detect the aimed CNG signal without being affected by an echo from the telephone line, and thus, time of retaining line and the time of waiting for the response of the opponent facsimile device can be shortened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine that responds by voice to an incoming telephone call, detects a CNG signal from a calling facsimile machine, and automatically switches to facsimile receiving operation.

0002

2. Description of the Related Art A facsimile machine having a voice response function is constructed as shown in FIG. When the called side facsimile machine 1 detects an incoming call from the calling side facsimile machine (not shown, hereinafter referred to as automatic transmission facsimile machine), a response voice signal [hereinafter referred to as The OGM signal] is generated, and this OG signal is generated.
The M signal is sent to a telephone line 6 via a changeover switch 3, an input/output amplifier circuit 4, and a telephone line interface circuit 5. The input/output amplifier circuit 4 includes a CNG detection circuit 7 that detects a CNG signal from an automatic sending facsimile machine.
is connected, and a CNG signal applied from a telephone line 6 via a telephone line interface circuit 5 is supplied to a CNG detection circuit 7 via an input/output amplifier circuit 4.

[0003] After the response audio signal sending circuit 2 finishes sending out the OGM signal, the CNG detection circuit 7 determines whether or not there is a signal component of "1100 Hz" included in the CNG signal.

[0004] When the CNG detection circuit 7 confirms the input of the CNG signal, the facsimile receiving circuit 8 shifts to a facsimile signal receiving operation. FIG. 4 shows a time chart from sending an OCM signal to receiving a facsimile signal. In FIG. 4, A indicates the point in time when the transmission of a response OCM is started after receiving a call from the transmitting side, and B indicates the point in time when the CNG detection circuit 7 shifts to a CNG signal detection operation. C indicates the point in time when the CNG detection circuit 7 detects the CNG signal and shifts to facsimile reception operation.

[0005] In this example, when the CNG detection circuit 7 detects the CNG signal twice, the facsimile receiving operation is started. When the facsimile machine 1 on the receiving side shifts to a facsimile reception operation, it sends out a response signal, and upon receiving this response signal, the automatic transmission facsimile machine shifts to a transmission operation at "time D".

Reference numeral 9 denotes a facsimile transmission circuit of the facsimile machine 1 on the receiving side, and during a transmission operation, the changeover switch 3 is set to the contact b side, and a facsimile signal is transmitted to the telephone line 6.

[0007]

[Problem to be solved by the invention] In such a configuration,
“1100” included in the OGM signal output from the response audio signal sending circuit 2 and passed through the changeover switch 3
Conventionally, the input/output amplifier circuit 4 includes a sidetone circuit in order to prevent the input/output amplifier circuit 4 from directly inputting the CNG component into the CNG detection circuit 5 from the input/output amplifier circuit 4. “1100Hz” included in the OGM signal
If the component returns as an echo from the telephone line 6, the CNG detection circuit 7 will react to this echo, causing a malfunction that indicates "CNG signal present" even when there is no CNG signal from the other party. Conventionally, the CNG detection circuit 7 is operated when the response audio signal transmission circuit 2 is turned off.
After "time point B" after finishing transmitting the GM signal, "1"
The system is configured to determine the presence or absence of a signal component of 100 Hz, and there is a problem in that the CNG signal cannot be detected while the OGM signal is being transmitted.

[0008] In this case, since it is not possible to respond to the CNG signal during the period from line connection to point B, the other party's facsimile machine continues to wait for a response. This is a problem because the transmission time of the CCITT recommendation of the other party's facsimile machine may time out and transmission becomes impossible before the transmission of the OGM signal ends.

[0009] Furthermore, it is uneconomical because the line is held unnecessarily long until the transmission of the OGM signal is finished. Therefore, in order to prevent the "1100 Hz" component from returning as an echo from the telephone line 6, a notch filter is provided between the response voice signal sending circuit 2 and the changeover switch 3 shown in FIG. It is conceivable that the "1100 Hz" component contained in the OGM signal generated from the signal sending circuit 2 is removed by a notch filter before being sent to the telephone line 6, but the configuration in which the notch filter is added in this way is Then, the OMC signal sent to telephone line 6 is “
Since the sounds centered around 1100 Hz are removed, a new problem arises in that the quality of the voice response signal is degraded.

The present invention has been made in view of the above-mentioned prior art, and is an audio system that can detect a CNG signal while transmitting an OGM signal, and also allows the "1100 Hz" component in the OGM signal to remain as much as possible. The purpose of this invention is to provide a facsimile device with a response function.

[0011]

[Means for Solving the Problems] A facsimile machine having a voice response function of the present invention detects an incoming call, transmits a response signal, detects a CNG signal from the calling party, and automatically switches to facsimile reception operation. In addition to configuring
Between the telephone line interface circuit and the response audio signal sending circuit that generates the response signal, switching is performed between a notch filter characteristic that attenuates a specific frequency component included in the CNG signal and a flat characteristic that does not attenuate the specific frequency component. The present invention is characterized in that a filter means is provided, and the filter means is configured to switch between a notch filter characteristic and a flat characteristic at prescribed intervals during the generation period of the response signal.

0012

According to this structure, by switching the filter means at a specified period, specific frequency components of the response signal sent to the telephone line are intermittently removed at the specified period.

Therefore, the CNG detection circuit that detects the CNG signal from the telephone line detects the CNG signal continuously for a predetermined period of time exceeding the continuous time of the specific frequency component of the response signal sent to the telephone line by the facsimile machine 1 on the receiving side. By detecting the specific frequency component, the CNG signal can be detected without being affected by echoes from the telephone line, thereby reducing the line holding time and the response waiting time of the other party's facsimile machine.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A facsimile apparatus with a voice response function according to the present invention will be described below based on one embodiment.

Components having the same functions as those in FIG. 3 showing the conventional example will be described with the same reference numerals. The facsimile apparatus with a voice response function of the present invention has the following feature: as shown in FIG.
This is different from the configuration diagram of the conventional device shown in FIG. 3, and accordingly, in this embodiment, the frequency characteristics of the filter means 10 and the detection timing and detection conditions of the CNG signal of the CNG detection circuit 7 are as follows. has been changed.

First, the configuration of the filter means 10 will be explained. [ The switching circuit 12 selects and outputs one of the FOGM signals (hereinafter referred to as the FOGM signal), and the switching circuit 12 is connected to the contact C.
When the switching circuit 12 is connected to the contact d side, the pass characteristic of the filter means 10 becomes a notch filter characteristic that attenuates a specific frequency component, and when the switching circuit 12 is connected to the contact d side, the pass characteristic of the filter means 10 is that the OGM signal is transmitted as is. It has a flat characteristic that allows it to pass through.

Here, in response to an incoming call from an automatic sending facsimile machine, an OGM signal is sent from the answering voice signal sending circuit 2, and the switching circuit 12 closes the contact c for a period "T1" as shown in FIG. 2(a). The switching operation of connecting to the side of contact d and connecting to the side of contact d over the next period "T2" is repeated at a period T.

Therefore, if we focus only on the "1100 Hz" component of the response signal actually sent to the telephone line 6 during the OGM signal sending period, the period "T1"
Due to the effect of 0, even if there is a 1100 Hz component in the OGM signal, it will not be sent out, and if the OGM signal has a 1100 Hz component in the period "T2", it will be sent out.

Specifically, “T1 > T2” and “T1=
2・T2''. Also, the period T is set to 100 seconds considering the auditory sense and the length of the CNG signal of 0.5 seconds.
It is set as m seconds.

Since the input/output amplifier circuit 4 includes a sidetone circuit as in the conventional case, the CNG detection circuit 7 is directly connected to the changeover switch 3 via the input/output amplifier circuit 4.
This situation can be reliably avoided by supplying the "1100 Hz" component to the "1100 Hz" component.

When a "1100 Hz" component is transmitted to the telephone line 6 at a period T as shown in FIG. 2(a),
As shown in (b), the "1100 Hz" component is intermittently returned from the telephone line 6 as an echo. This echo does not continue for more than the period "T2" from the operation timing of the switching circuit 12.

Therefore, in the CNG detection circuit 7 of this embodiment, as shown in FIG. 2(d), the "1100 Hz" component is
If the signal continues for more than T2'', it is determined that there is a CNG signal.Therefore, in this embodiment, the switching circuit 12 is fixed to the contact c side from time E in FIG. 2(a). Since the CNG signal interval is 3 seconds as shown in Figure 2 (c), the next CNG signal can be detected after a maximum of about 3 seconds. .

Here, the reason why the switching circuit 12 is fixed to the contact c side is to avoid the echo of the "1100 Hz" component of the OGM signal and the C
This is to prevent a part of the CNG signal from being canceled by the echo of the OGM signal and becoming discontinuous when the NG signals have opposite phases and similar levels.

In this embodiment, the switching period T of the switching circuit 12 is set to "T1>T2", and the reason for this will be explained. Considering the case of "T1≦T2", in this case, the echo duration of the "1100 Hz" component of the OGM signal is the maximum "T2". It is conceivable that a CNG signal of opposite phase and same level is input simultaneously with this echo. At this time, the echo and CNG signal cancel each other out,
The duration of the "1100 Hz" component input to the CNG detection circuit 7 is T1. However, the CNG detection circuit 7
is the switching circuit 1 when the “1100Hz” signal is input.
It is not possible to determine which switching state the signal is in. Therefore, if "T1≦T2", it may not be possible to determine whether the signal is a CNG signal or a signal of the "1100 Hz" component of an OGM signal. In particular, even when "T1=T2", under the above-mentioned conditions, it is not possible to determine whether the "1100 Hz" component of the "T1" period is input or the echo input of the "T2" period is present.

Therefore, by setting "T1>T2" and setting the ratio to about "2:1", discrimination becomes easier. In the above embodiment, the filter means 10 is replaced by a notch filter circuit 11.
and a switching circuit 12, which uses a filter that can switch the input/output characteristics between a notch filter characteristic that attenuates a specific frequency component and a flat characteristic that does not attenuate a specific frequency component according to the signal at the control terminal. It can also be achieved.

[0026]

[Effects of the Invention] As described above, the facsimile device with voice response function of the present invention detects an incoming call, transmits a response signal,
The system is configured to automatically switch to facsimile reception operation by detecting a CNG signal from the calling side, and is provided between the telephone line interface circuit and the response audio signal transmission circuit that generates the response signal, which is included in the CNG signal. filter means that can be switched between a notch filter characteristic that attenuates a specific frequency component and a flat characteristic that does not attenuate the specific frequency component, and the filter means is defined between the notch filter characteristic and the flat characteristic during the generation period of the response signal. Since the configuration is configured to switch periodically, specific frequency components of the response signal sent to the telephone line are intermittently removed at the specified period.

Therefore, the CNG detection circuit that detects the CNG signal from the telephone line detects the specified frequency component continuously for a predetermined time period exceeding the continuous time period of the specific frequency component of the response signal sent to the telephone line by the facsimile machine on the receiving side. By detecting the frequency component, the CNG signal can be detected without being affected by echoes from the telephone line, thereby reducing the line holding time and the response waiting time of the other party's facsimile machine.

Furthermore, rather than completely removing specific frequency components in the response signal, the specific frequency components are intermittently removed to prevent them from disappearing as much as possible, which significantly deteriorates the quality of the voice response. The device can be realized without any

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a facsimile apparatus with a voice response function according to the present invention.

FIG. 2 is a waveform diagram of main parts of the device.

FIG. 3 is a configuration diagram of a conventional facsimile device with a voice response function.

FIG. 4 is a waveform diagram of main parts of the device.

[Explanation of symbols]

2 Response audio signal sending circuit 3
Selector switch 4 Input/output amplifier circuit 5 Telephone line interface circuit 6
Telephone line 7 CNG detection circuit 8 Facsimile reception circuit 10 Filter means 11 Notch filter circuit 12 Switching circuit

Claims (2)

[Claims] 1. A system configured to detect an incoming call and transmit a response signal, detect a CNG signal from a calling side and automatically switch to facsimile receiving operation, and generate a telephone line interface circuit and the response signal. A filter means capable of switching between a notch filter characteristic that attenuates a specific frequency component included in the CNG signal and a flat characteristic that does not attenuate the specific frequency component is provided between the response audio signal sending circuit and the response signal generating circuit. A facsimile machine with a voice response function configured to switch filter means between a notch filter characteristic and a flat characteristic at specified intervals during a period. [Claim 2] The characteristic switching period of the filter means is
2. A facsimile apparatus with a voice response function according to claim 1, wherein the notch filter characteristic period is set to be longer than the flat characteristic period.