JPH10322421A - Telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a telephone set in which mis-detection of a DTMF signal due to a side tone is avoided without deteriorating the quality of a talker voice. SOLUTION: A telephone set has a device control section 15 that controls the operation of the telephone set based on information of presence of a DTMF signal detected from a connected trunk line or a content of the DTMF signal, a couple of DTMF signal detection sections 12, 13 that detect a DTMF signal from a reception voice path and a transmission voice path, and a detection result discrimination section 14 that compares outputs of a couple of the DTMF signal detection sections 12, 13. In the case that the detection result discrimination section 14 discriminates presence of the DTMF signal in a reception signal only from a trunk line 10, the discrimination section 14 informs the content of the DTMF signal or presence signal information of the DTMF signal or both the content of the DTMF signal and the presence signal information to the device control section 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a dual tone multi-
All telephones and mobile communication devices having a function of controlling the operation of the apparatus by a frequency signal (hereinafter referred to as a DTMF signal) will be collectively referred to as telephones.

[0002]

2. Description of the Related Art Examples of a conventional telephone including a device for detecting a DTMF signal received from an office line will be described with reference to the drawings. 3 is a block diagram showing a circuit configuration of a first example of a conventional telephone, FIG. 4 is a block diagram showing a circuit configuration of a second example of the conventional telephone, and FIG. 5 is a circuit configuration of a third example of the conventional telephone. FIG. 6 is a block diagram showing a circuit configuration of a fourth example of a conventional telephone.

First, the example of FIG. 3 will be described. In this circuit, a DTMF detector 32 receives a signal received from a local line 30 via a two-wire / four-wire conversion circuit 31 and a DTMF detector 32.
A signal is detected, and signaled information and signal content of the DTMF signal are notified to the device control unit 33. The device control unit 33 receives the DTMF signal from the office line, and
Simultaneously with the detection of the TMF signal, a voice is recorded in the voice recording unit 34, or the voice is reproduced by the voice reproducing unit 35, and the voice is transmitted to the office line 30 through the call control unit 36. Sound collection microphone when transmitting or during a call
When the speaker's voice is input from 38 and the voice signal is transmitted to the central office line 30, the voice signal transmitted from the voice reproducing unit 35 or the sound collecting microphone 38 is converted to the sidetone by the two-wire / four-wire conversion unit 31. As a result, there is a possibility that the signal may wrap around the receiving voice path and be erroneously detected as a DTMF signal. Further, when a DTMF signal is included in the audio signal reproduced and transmitted from the audio reproducing unit 35, the DTMF signal from the office line 30 is also erroneously detected due to the side tone.

Next, the example of FIG. 4 will be described. The circuit configuration shown in FIG. 4 is different from the circuit configuration shown in FIG.
Since the echo canceller section 40 is inserted between the line conversion circuit 31 and the DTMF detection section 32, and the other configuration is the same, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. In this configuration, the DTMF detection unit 32 is removed by removing the side tone of the signal transmitted from the sound reproduction unit 35 or the sound collection microphone 38 to the local line 30 by the echo canceller unit 40.
Erroneous detection due to sidetones in the above can be reduced. However, in this configuration, if the echo canceller unit 40 cannot obtain a sufficient amount of echo reduction, the configuration is substantially the same as that of FIG. 3 and erroneous detection due to side sounds occurs.
In general, the echo canceller unit 40 cannot obtain a sufficient amount of echo reduction when the transfer characteristic of the echo path has nonlinearity. However, the two-wire / four-wire conversion unit 31 of the telephone depends on the connected line conditions. Signal distortion often occurs in sidetones, and it is very difficult for the sidetone path, that is, the echo path, to have sufficient linearity. In the configuration of FIG. Depending on conditions, it is not only impossible to completely eliminate erroneous detection due to sidetones, but inserting the echo canceller 40 is disadvantageous in terms of cost.

Next, an example shown in FIG. 5 will be described. The circuit configuration shown in FIG. 5 differs from the circuit configuration shown in FIG.
Are inserted, and the other configurations are the same. Therefore, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. In this configuration, the device control unit 33 includes a DTMF detection unit.
When the result of the detection of the presence of the DTMF signal is notified from 32, the voice cutoff unit 50 temporarily cuts off the transmission signal to the office line 30. At this time, if the DTMF detection unit 32 has erroneously detected a side tone, the detection result changes to a detection result indicating that there is no DTMF signal due to the disconnection of the transmission signal. As a result, the device control unit 33 determines that the signal information from the DTMF detection unit 32 is an erroneous detection due to sidetone. DTMF
If the detection result that there is a signal is not a false detection due to sidetone,
Even after the transmission signal is cut off, the detection result of the presence of the DTMF signal is continuously notified, and the device control unit 33 determines that the presence signal information is notified by the DTMF signal received from the station line, and determines the signal content. Is performed according to. However, in the case of this configuration, the transmitted voice is cut off due to erroneous detection by the transmitted voice, and there is a problem of giving a sense of incongruity to the other speaker. It is necessary to simultaneously cut the transmission signal while the signal information is notified, and if the detection delay time from the input of the DTMF signal to the notification of the signal information is large, the actual signal input timing Therefore, there is a problem in that the detection result does not change even after the signal disconnection because the time difference occurs in the transmission signal disconnection timing.

Next, the example of FIG. 6 will be described. The circuit configuration shown in FIG. 6 differs from the circuit configuration shown in FIG. 3 in that a DTMF frequency removal filter 60 is inserted in the transmission voice path. Are the same, the same parts are denoted by the same reference numerals and detailed description thereof will be omitted. in this case,
Since the frequency component of the DTMF signal is removed from the transmission signal, erroneous detection does not occur due to side sounds, but the same component as the DTMF signal is removed from the voice of the speaker, thereby deteriorating the transmission sound quality. There is.

[0007]

As described above, in the configuration of FIG. 3, erroneous detection occurs due to the wraparound of the side tone by the two-wire / four-wire conversion circuit, and in the configuration of FIG. 4, erroneous detection is performed by the echo canceller. Although the frequency is reduced, erroneous detection occurs due to the condition of the telephone line to be connected. In the configuration of FIG. 5, the sense of incongruity to the speaker for temporarily cutting off the signal transmitted to the office line, and the detection of the DTMF detection unit There is a problem that the effect of removing the erroneous detection is only effective when the delay time is very small. Further, in the configuration of FIG. 6, since the frequency component of the DTMF signal is removed from the speaker voice, the sound quality of the speaker voice is reduced. Each of the conventional examples has various problems in that the image quality deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a telephone capable of eliminating erroneous detection of a DTMF signal due to a side tone without deteriorating the sound quality of a speaker's voice. I do.

[0009]

According to the present invention, there is provided a telephone having a device control section for controlling the operation of the device based on information on the presence or absence of a DTMF signal detected from a connected office line or the content of the DTMF signal. And a pair of Ds for detecting a DTMF signal from the reception voice path and the transmission voice path.
A TMF signal detector, and a detection result determiner for comparing the outputs of the pair of DTMF signal detectors. Only when the detection result determiner determines that there is a DTMF signal only in the received signal from the office line, The content of the DTMF signal, or the signal information of the DTMF signal, or the DTMF
The information of both the content of the signal and the signal information is notified.

According to the present invention, erroneous detection of a DTMF signal due to side sounds can be eliminated without deteriorating the sound quality of a speaker's voice.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows Embodiment 1 of a telephone according to the present invention.
2 is a block diagram showing a circuit configuration in the embodiment, in which 10 is a connected office line, 11 is a 2-wire 4-wire conversion circuit, 12 and
Reference numeral 13 denotes a pair of DTMF detection units connected to the reception voice path and the transmission voice path, respectively, 14 denotes a detection result determination unit that compares and detects the detection results of the DTMF detection unit 12 and the DTMF detection unit 13, and 15 denotes the entire telephone set. Device control unit for controlling the operation,
Reference numeral 16 denotes a voice recording unit for recording received voice, etc., 17 denotes a voice recording unit for reproducing voice data and the like stored in the telephone 16 and the telephone in advance, and 18 denotes a source of a signal to be transmitted to an office line. A call control unit for switching to the reproduction unit 17 or the sound collecting microphone 110, a receiver 19 for converting a received voice into an acoustic signal, and a sound collecting microphone 110 for converting a speaker's voice into an electric signal.

[0012] Here, the detection result judging section 14 sets the D on the receiving side.
Only when the signal information is notified from the TMF detection unit 12 and the DTMF detection unit 13 on the transmitting side notifies that there is no DTMF signal, the device control unit 15 is notified of the presence of the DTMF signal. When both the DTMF detecting unit 12 on the receiving side and the DTMF detecting unit 13 on the transmitting side are notified of the presence signal, the operation is performed so as not to notify the device control unit 15 of the presence of the DTMF signal. . When the telephone is connected to the office line 10 and the DTMF signal in the reception signal from the office line 10 is detected and the operation of the telephone is controlled based on the content of the signal, the operation from the audio reproducing unit 17 to the user is performed. Guidance voice, voice message for automatic answering machine, etc. may be sent to the office line.
May transmit the voice of the speaker to the office line. In these cases, the voice transmitted to the office line 10 is circulated as a side tone generated by the two-wire / four-wire conversion circuit 11 to the receiving voice path, and is input to the DTMF detection unit 12 connected to the receiving voice path. DTMF detector connected to the transmission voice path
13 is also entered at the same time.

Next, the operation when the DTMF signal is erroneously detected in the DTMF detector 12 due to the side tone will be described below. When the sidetone is input, the receiver D
If the TMF detector 12 detects a DTMF signal by mistake,
The presence / absence information of the DTMF signal is notified to the detection result determination unit 14 as the detection result. At this time, since the transmitted voice that is the basis of the side tone is input to the transmitting side DTMF detecting unit 13, the DTMF detecting unit 13 also determines that there is a DTMF signal, and detects the presence signal information as a detection result. The result determination unit 14 is notified. Thus, both DTMF detectors 12 and DT
When signal information is notified from the MF detection unit 13, the detection result determination unit 14 sends a DTMF to the device control unit 15.
Since the notification of the presence of the signal is not performed, the apparatus does not perform an erroneous operation due to the signal content erroneously detected by the DTMF detector 12.

Next, the operation when a DTMF signal is received from a station line will be described. In this case, DTMF
The signal is sent to the DTMF detector 12 connected to the receiving voice path.
Therefore, the DTMF detection unit 12 notifies the detection result determination unit 14 of the presence signal information. However, since the reception signal from the local line 10 is not input to the DTMF detection unit 13 connected to the transmission voice path, the DTMF detection unit 13 does not notify the detection result determination unit 14 of the signal information. At this time, the detection result judging unit 14 reads the contents of the DTMF signal received from the DTMF detecting unit 12 on the receiving side, and controls the operation of the telephone. Also, the DTM included in the transmission signal to the office line 10
The DTMF detection unit 13 on the transmitting side uses the DTMF
There may be a slight time difference between the section in which the signal is detected and the section in which the DTMF detector 12 on the receiving side detects the presence of the DTMF signal due to the side tone of the signal. Even when sound is being input, the DT of the receiver
Only the MF detector 12 detects that the DTMF signal is present, and the transmitting side DTMF detector 13 has a section in which the DTMF signal is detected to be absent. However, since this section is considered to be a very short section, if the maximum time width of the section is grasped in advance, the device control unit 15 will set the detection result determination unit 14 to a time longer than the maximum time width. Only when the notification of the presence of the DTMF signal from
By judging that the F signal has been received, it is possible to remove erroneous detection due to the sidetone.

As described above, according to the present embodiment, the DTM based on the side tone can be used without deteriorating the sound quality of the transmission signal.
Erroneous detection of the F signal can be eliminated.

(Embodiment 2) FIG. 2 is a block diagram showing a circuit configuration of a telephone set according to Embodiment 2 of the present invention. In FIG. Circuit, 22 and 23 are a pair of TMF detecting sections connected to the receiving voice path and the transmitting voice path, respectively.
A detection result determination unit that compares and detects the detection results of the MF detection unit 22 and the DTMF detection unit 23, 25 is a device control unit that controls the operation of the entire telephone, 26 is a voice recording unit that records a received voice, and 27 is a voice The sound reproducing unit 28 reproduces sound data and the like stored in the recording unit 26 and the telephone in advance. The sound reproducing unit 28 generates a signal to be transmitted to the office line.
A speech control unit 29 for converting a received voice into an audio signal; a sound collecting microphone 210 for converting a speaker's voice into an electric signal; a 211 DTMF detecting unit 22 on the receiving side and a DTMF on the transmitting side; This is a DTMF signal content comparison unit that compares the contents of the signals detected by both the detection units 23.

The operation will now be described. DTM
The F signal content comparison unit 211 compares the content of the signal detected by the DTMF detection unit 22 on the receiving side with the content of the signal detected by the DTMF detection unit 22 on the transmission side, and determines whether the content is the same. The detection result determination unit 24 is notified whether the contents are different. The detection result determination unit 24 is notified of the presence signal information from the DTMF detection unit 22 on the receiving side, and the DTMF detection unit 23 on the transmission side.
Is notified that there is no DTMF signal, the DTMF signal is sent to the device control unit 25 as in the first embodiment.
Notification that the F signal is present is performed. Also, when signaled information is notified only from the DTMF detection unit 13 on the transmitting side,
As in the first embodiment, the operation is performed so as not to notify the device control unit 25 of the presence of the DTMF signal. Embodiment 1
The operation different from the above is performed by the DTMF detector 22 on the receiving side,
This is a case where signal information is notified from both the DTMF detection unit 23 on the transmitting side. At this time, in Embodiment 1,
Although the device control unit 25 is not notified of the presence of the DTMF signal, in this embodiment, when the comparison result of the DTMF signal content comparison unit 211 determines that the content of both DTMF signals is different, The detection result determination unit 24 is a device control unit.
25 is notified that a DTMF signal is present. Conversely, both D
If it is determined that the contents of the TMF signals are the same, the detection result determination unit 24 operates so as not to notify the device control unit 25 of the presence of the DTMF signal. In the first embodiment, when the DTMF detection unit 23 detects the presence of the DTMF signal by the transmission signal to the office line and simultaneously receives the DTMF signal from the office line, the detection result determination unit 24 notifies the presence of the DTMF signal. Does not go to the device control unit 25, the DTMF signal received from the central office is ignored. However, in the present embodiment, the transmitting side DTMF detecting unit 23
When the DTMF signal is notified to the detection result judging unit 24 at the same time as the DTMF signal is received from the office line at the same time, if the contents are different, the detection result judging unit 24 In order to notify the control unit 25 of the presence of the DTMF signal, the device control unit 25 can control the operation of the telephone by the DTMF signal received from the office line.

As described above, according to the present embodiment, erroneous detection of a DTMF signal due to a side tone can be more reliably removed without deteriorating the sound quality of a transmission signal.

[0019]

As described above, according to the present invention, the frequency component of the DTMF signal included in the transmission signal to the office line is received from the office line while being included in the reception signal as the side tone. Even if a DTMF signal is detected, erroneous detection due to sidetones can be reliably removed, and processing for cutting off a signal transmitted to the office line or removing a part of the frequency can be performed. Since false detection due to side sounds can be eliminated without performing, there is an advantageous effect that erroneous detection due to side sounds can be eliminated without a problem of giving a sense of incongruity to a user without interruption of a transmitted signal or deterioration of sound quality. Can be

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a telephone according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a telephone according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of a first example of a conventional telephone.

FIG. 4 is a block diagram showing a circuit configuration of a second example of a conventional telephone.

FIG. 5 is a block diagram showing a circuit configuration of a third example of a conventional telephone.

FIG. 6 is a block diagram showing a circuit configuration of a fourth example of a conventional telephone.

[Explanation of symbols] 10, 20 ... office line, 11, 21 ... 2-wire 4-wire conversion circuit, 12, 22
… Reception path DTMF signal detector, 13, 23… Transmission path D
TMF signal detection unit, 14, 24 ... detection result judgment unit, 15, 25
... Device control unit, 16, 26 ... Voice recording unit, 17, 27 ... Voice reproduction unit, 18, 28 ... Call control unit, 19, 29 ... Receiving receiver, 110, 210 ... Sound collecting microphone, 211 ... DTMF signal content comparison Department.

Claims (2)

[Claims] 1. DT detected from a connected office line
What is claimed is: 1. A telephone having a device control unit for controlling the operation of a device based on information on the presence or absence of an MF signal or the content of a DTMF signal, comprising: a pair of DTMF signal detection units for detecting a DTMF signal from a reception voice path and a transmission voice path And a detection result determination unit that compares the outputs of the pair of DTMF signal detection units. Only when the detection result determination unit determines that only the reception signal from the station line has a DTMF signal, the device control unit A telephone set for notifying the content of a DTMF signal, the signal information of a DTMF signal, or the information of both the content of a DTMF signal and the signal information. And a signal content comparing section for comparing the contents of the signals detected by the pair of DTMF signal detecting sections, and when the contents of the signals are different, signaled information of the DTMF signal or the contents of the DTMF signal, or 2. The telephone according to claim 1, wherein both the signaled information and the content of the DTMF signal are notified to the device control unit, and when the content of the signal is the same, the information is not notified. .