JP3492257B2 - Telephone equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of simultaneously reproducing a received voice signal input from a telephone line as an acoustic output from a speaker and transmitting a transmitted voice signal collected by a microphone to a telephone line. The present invention relates to a telephone device (speakerphone) that enables heavy hands-free communication.

[0002]

2. Description of the Related Art In recent years, a telephone device has been provided with a speakerphone function which enables a telephone conversation without having a receiver. A speaker that acoustically reproduces a received voice signal is used so that the receiver does not have to be held in the hand and brought close to the ear. If the received voice signal acoustically reproduced from the speaker enters the microphone for collecting the transmitted voice signal, howling may occur. However, this can prevent the howling of a telephone with a speaker by the echo canceller technology (device: these days, these are dedicated devices). by this,
A more natural full-duplex speakerphone is possible. Further, in a telephone having a speakerphone function, it is also necessary to keep the level of the received voice signal acoustically reproduced from the speaker appropriate. This has a built-in AGC (auto gain controller) circuit and fulfills this function. Also,
There is a half-duplex speakerphone that does not have an echo canceller, but this is a method for making a call by switching between transmitting and receiving.

[0003]

However, when the line is closed by the line closing circuit when an incoming call arrives, the
The line current suddenly flows to the secondary side, and large pulse-shaped noise is generated on the secondary side of the transformer. This noise is received AG
When input to the C circuit, the reception AGC circuit makes the gain extremely small, and adjusts the output for a large noise so that the output is within an appropriate level. Although the operation of automatic gain adjustment responds momentarily in the direction of suppressing the increase in volume,
The operation in the direction of increasing the volume has a characteristic of being slow. Although such a characteristic is preferable to suppress an excessive output, if the recovery takes time after the gain becomes extremely small due to the large pulse noise generated in the transformer, the speakerphone immediately after the call starts The received voice reproduced from is initially small, and the volume gradually becomes appropriate over time, which is unnatural.

Further, in recent years, in order to select a carrier and make a call, it is necessary to download data such as a call charge at that time. At that time, even if the speakerphone responds, the microphone is muted for a certain period of time in order to determine whether it is a download data or a call. Speakerphone circuit (modem section) is used to judge whether it is download data or a call
DTMF detection, etc. are performed to make a judgment. Microphone mute is muted by the transmission AGC circuit in the speakerphone circuit (modem section). As a result, the received voice reproduced during mute and after mute release is changed. This is because when the microphone and speaker are both deactivated, it operates at full duplex, but at this time, the echo canceller works on the AGC circuit to suppress the speaker volume and the microphone volume so that howling does not occur. It works by suppressing the input level. Then, when the microphone is muted, howling does not occur, so the echo canceller does not work (becomes half-duplex movement), and the reception AGC circuit is held at the gain amount when operating at full duplex. . Therefore, the speaker volume always changes depending on the gain amount of the reception AGC circuit immediately before the mute of the microphone. This is initially small, and the problem is that the volume gradually becomes appropriate and unnatural as time goes by, and the problem that it becomes large and suddenly appropriate and unnatural at first, sometimes large and sometimes small The problem arises.

Similarly, even when a call is made, when the line is closed by pressing the speakerphone key of the operation unit, dial operation is performed from now on. Therefore, the transmission AGC circuit in the speakerphone circuit (modem unit) mutes the microphone. There is.
As a result, the volume of the received voice output from the speaker 21 is changed between when muted and after unmuting. This is because it operates in full duplex when both the microphone and speaker are deactivated, but at this time, it operates by suppressing the speaker volume and suppressing the microphone input level so that howling does not occur. To do. And if you mute the microphone, howling will not occur,
The echo canceller does not work (becomes half-duplex operation), and the receiving AGC circuit is held at the gain amount when it was operating at full duplex. Therefore, the speaker volume always changes depending on the gain amount of the reception AGC circuit immediately before muting the microphone. Therefore, the volume of DT (dial tone) heard from the speaker is suddenly high or low at first, and the volume gradually becomes appropriate as time goes by, which is unnatural, or it remains high or low. There is a problem that it is.

The same applies to RBT (ringback tone) after dialing.

In addition, since the polarity of the line voltage is inverted due to the telephone line being closed on the other side, the direction of the current flowing through the primary side of the transformer changes abruptly. However, there is an unnatural problem that the volume is low immediately after the start of a call and becomes appropriate over time.

Similarly, there is a microphone mute operation during a call, which is a function used, for example, in an operation of only listening to information such as a weather forecast from a speaker. At this time, it is difficult to hear in full-duplex operation. In some cases, the user performs mute operation on the microphone and changes to half-duplex operation. At this time, since the echo canceller does not work (becomes a half-duplex operation), the reception AGC circuit when operating in full-duplex is held by the gain amount at that time, as in the above description. Therefore, the speaker volume always changes depending on the gain amount of the reception AGC circuit immediately before muting the microphone. This may be done if the gain value of the AGC circuit is appropriate, but if the gain value is small, the volume heard from the speaker is very small, and if the gain value is large, the sound is broken and it is difficult to hear.

In the prior art, regarding the volume change due to the polarity reversal noise due to the closing of the telephone line, there is a thing that the circuit is disconnected for a certain time after the polarity reversal, but the modem setting is performed before and after the polarity reversal. Change, microphone mute operation related to a series of speakerphone operations, and reception side AG
Turn off C, set a fixed gain value in this AGC circuit as a set value, and receive AGC when microphone mute is released.
There is nothing to deal with an unnatural change in volume by turning on and operating as a full-duplex speakerphone.

An object of the present invention is to perform a microphone mute operation and a reception side AGC off in a series of operations of a speakerphone, set a fixed gain value as a set value in this AGC circuit section, and when the microphone mute is released. By turning on the receiving AGC and operating as a full-duplex speakerphone,
It is an object of the present invention to provide a telephone device capable of suppressing an unnatural volume change and producing a clear volume.

[0011]

Therefore, in the present invention, the full-duplex operation of the speakerphone and the half-duplex operation in which the reception AGC is turned off and the fixed gain is set are set separately to make a more stable and natural operation. It allows you to get a call.

In the present invention, the telephone line is connected to the primary side of the transformer, the secondary side of the transformer, the speaker for reproducing the received voice signal as an acoustic output, and the microphone for collecting the transmitted voice signal. It is equipped with an automatic gain adjusting means and an echo canceling means for performing an echo canceling process for keeping the levels of the received voice signal and the transmitted voice signal appropriately, respectively, and operates as a full-duplex speakerphone, but echoes when the microphone is muted. In a telephone device that operates as a half-duplex speakerphone by canceling the canceller's operation and holding the automatic gain adjustment means on the receiving side by the amount of gain at that time, mutes the microphone when calling to the telephone line and automatically A control procedure for turning off the gain adjusting means and setting a fixed gain value as a set value in the automatic gain adjusting means. The provided.

According to another aspect of the present invention, the control means turns off the automatic gain adjusting means on the receiving side as it is when the RBT is received after transmitting the dial signal and sets a fixed gain value to the automatic gain adjusting means as a set value. Leave it set and use the polarity reversal detection means to detect the polarity reversal, and after the fixed time has passed, turn on the receiving side automatic gain adjustment means and cancel the microphone mute so that the call is ready. Control.

In the present invention, the telephone line is connected to the primary side of the transformer, the secondary side of the transformer, the speaker for reproducing the received voice signal as an acoustic output, and the microphone for collecting the transmitted voice signal. It is equipped with an automatic gain adjusting means and an echo canceling means for performing an echo canceling process for keeping the levels of the received voice signal and the transmitted voice signal appropriately, respectively, and operates as a full-duplex speakerphone, but echoes when the microphone is muted. In a telephone device that operates as a half-duplex speakerphone by canceling the canceller's operation and holding the automatic gain adjustment means on the receiving side with the amount of gain at that time, turn off the automatic gain adjustment means on the receiving side when receiving a call from the telephone line. However, the automatic gain adjusting means includes a control means for setting a fixed gain value as a set value. Apparatus.

According to another aspect of the present invention, the control means uses means for counting the passage of a fixed time after the arrival of an incoming call, and turns on the receiving side automatic gain adjusting means after the passage of the fixed time.
The microphone is muted and the call is controlled so that it can be used.

In the present invention, the telephone line is connected to the primary side of the transformer, the secondary side of the transformer, the speaker for reproducing the received voice signal as an acoustic output, and the microphone for collecting the transmitted voice signal. A full-duplex speakerphone is provided with an automatic gain adjusting means for keeping the levels of the received voice signal and the transmitted voice signal appropriately, an echo canceling means for performing echo canceling processing, and an operating means for performing a mute operation of the microphone. Although it operates, the echo canceller does not work when the microphone is muted, and the automatic gain adjusting means on the receiving side is held by the gain amount at that time and operates as a half-duplex speakerphone. In response to the microphone mute operation, the automatic gain adjustment means on the receiving side is turned off and this automatic gain adjustment It provided a control means for setting the gain value of the fixed as a set value in the unit. In claim 6, the control means, after the mute operation of the microphone during a call,
In response to the microphone mute release operation, the microphone mute is released, and the receiving side automatic gain control means is turned on so that the communication is possible.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic electrical configuration of a speakerphone 24 according to an embodiment of the present invention. A telephone line network 1 such as a public telephone line network has a line closing circuit 2 for closing a line.
Is connected to the primary side of the transformer 3. Transformer 3
A hybrid circuit 4 is connected to the secondary side of the above, and sorts a received voice signal and a transmitted voice signal. A main controller 5 that is realized by a microcomputer or the like and controls the telephone device 24 according to a preset program.
Controls the operation of the speakerphone when the user presses down the operation unit (speakerphone key) 6. Amplifiers 7, 8, 9, and 10 are provided for electrically amplifying the transmitted voice signal and the received voice signal. Signal processing for the transmitted voice signal and the received voice signal is performed in the speakerphone communication circuit (modem unit) 11.

The speakerphone communication circuit (modem section) 11 is
Echo cancellation and automatic gain adjustment (abbreviated as "AGC") are performed as one digital signal processing semiconductor integrated circuit. In the speakerphone call circuit 11, a D / A that outputs a transmission voice signal to the hybrid circuit 4 via the amplifier 7
(Digital-analog conversion circuit) 12, D / A (analog-digital conversion circuit) 13 that outputs a reception voice signal via the amplifier 10, A / D 14 that inputs the reception voice signal from the amplifier 8, and transmission from the amplifier 9 An A / D 15 for inputting a voice signal is included. An LEC: line-side echo cancel circuit 16 is provided to remove the transmitted voice signal component from the received voice signal. An AEC: acoustic echo cancel circuit 17 is provided to remove the received voice signal component from the transmitted voice signal. A transmission AGC circuit 18 and a reception AGC circuit 19 are respectively provided as automatic gain adjustment means for performing automatic gain adjustment so that the levels of the transmission voice signal and the reception voice signal become appropriate.

The transmitted voice signal is collected by the microphone 20, amplified by the amplifier 9, input to the A / D 15, and converted into a digital signal. The received voice signal is D /
After being converted into an analog signal by A13, the amplifier 1
The power is amplified by 0 and reproduced as an acoustic output from the speaker 21. AEC: Acoustic side echo cancellation circuit 17
Prevents the reception voice signal reproduced as a sound output from the speaker 21 from being collected by the microphone 20 and being transmitted together with the transmission voice signal. LEC: The line side echo cancellation circuit 16 is a state in which the transmission voice signal output from the amplifier 7 and given to the hybrid circuit 4 is amplified by the amplifier 8 as a reception side voice signal and converted from the A / D 14 into a digital signal. Eliminate wraparound with.

In this embodiment, the path of the received voice signal from the secondary side of the transformer 3 to the amplifier 8 via the hybrid circuit 4 and the transmission of the received voice signal from the secondary side of the transformer 3 to the amplifier 7 via the hybrid circuit 4. A cross point SW circuit 23 capable of switching the path disconnection of the voice signal is provided and can be controlled by the control unit 5. This cross point S
Although not shown in the figure, the handset W also makes a handset call and switches a call path of a cordless handset or the like.
Further, a telephone line polarity reversal detection circuit 22 is inserted between the telephone line network 1 and the line connection circuit 2, and when a polarity reversal of the telephone line is detected, a detection output is given to the control unit 5.

FIG. 2 shows the operation of the control unit 5 of the speakerphone 24 of FIG.

The operation is started from S200. In this state, both the microphone and the speaker are muted. S201
Then, it is determined whether or not an input operation of pressing down the speakerphone key 6 is performed. When it is determined that the push-down operation is performed, the telephone line network 1 is determined in step S202.
It is determined whether or not the call signal from is received. When it is received, first in S216, the line is closed, and a command for connecting to the speakerphone communication circuit 11 side is sent to the crosspoint SW23. Then, in step S217, a weight of a fixed time is applied according to an instruction from the control unit 5. This is because the polarity reversal noise that occurs when the line is closed, the noise that occurs when the crosspoint SW23 is connected, and the time until the connection is made considering that a wireless unit such as a cordless telephone is connected. Is set. The speakerphone call circuit 11 is executed in S218 by the command of the control unit 5.
First, the speakerphone setup process is performed. In the process, the reception AGC is set to OFF. In step S219, a fixed gain is written in the reception AGC. This allows
The state is such that only the received voice signal enters the call state. Here, in S220, a data download signal (DTMF or the like) from the carrier is detected. Here, if detected, the speaker is also muted and the data download process of S221 is performed. Return to standby and wait for speakerphone key input. If no data download signal (DTMF or the like) from the carrier is detected in S220, the reception AGC is set to ON in S206 by an instruction from the control unit 5,
The microphone mute is released in S207, and the setting of the full-duplex speakerphone is completed in S208. As a result, the voice signal input from the other side and the voice input on the own side are opened to the speakerphone call circuit 11, and the call becomes possible.
At 09, a call in the speakerphone state is formed.

Next, when it is determined in S202 that the call signal is not received, the control unit 5 issues an instruction to S203.
Sets the reception AGC of the speakerphone communication circuit 11 to OFF, and the reception AG of the speakerphone communication circuit 11 is set in S204.
Write a fixed gain in C. As a result, DT (dial tone) from the telephone network is heard, but it always sounds as a constant volume. In S205, it is determined whether or not a calling operation is being performed on the telephone line network 1. If there is no call operation, the speakerphone key is pressed again to return to standby. If it is determined in S205 that there is a calling operation, a calling operation is executed in S222. After the calling operation is completed, an RBT (ringback tone) is heard, and at this time, the settings of S203 and S204 are held and the microphone mute operation is continued. Then, the polarity reversal detection circuit 22 detects the polarity reversal. When the polarity reversal is detected in S223, the wait is executed for a fixed time set by the command of the control unit 5, the reception AGC is set to ON in S206, and S207 is set. The microphone mute is canceled with, and the setting of the full-duplex speakerphone is completed in S208. As a result, the voice signal input from the other side and the voice input on the own side are opened in the speakerphone call circuit 11, and the call becomes possible.
At 209, a call is formed in the speakerphone state.

Next, the microphone mute operation during the call in S209 will be described.

First, in S210, if an operation for disconnecting the call ending line is performed, the operation ends in S230 and the process returns to the standby. If the call termination line is not disconnected in S210, it is determined in S211 whether the microphone mute operation during the call is performed. If the mute operation during the call is not performed, the call continues in S209. When the microphone mute during the call is executed in the operation unit 6 in S211, the reception AGC of the speakerphone communication circuit 11 is set to OFF in S212 by the command of the control unit 5, and fixed in the reception AGC of the speakerphone communication circuit 11 in S213. Write the gain. As a result, the device operates as a call monitor in S214, and the volume of sound coming in from the telephone line network is always constant. S2
If the microphone mute release operation during the call is not performed in 15, the call monitor state of S214 is continued. S21
If the microphone mute release operation during the call in 5 is performed, the control unit 5 gives an instruction to set the reception AGC to ON in S206,
The microphone mute is released in S207, and the setting of the full-duplex speakerphone is completed in S208. As a result, when the voice signal from the other side is input to the speakerphone call circuit 11 again, the voice input on the own side is opened and the call becomes possible.
At 209, a call is formed in the speakerphone state.

As described above, according to the embodiment of the present invention, in a series of operations of the speakerphone, when the microphone is muted, the reception side AGC is turned off, and a fixed gain value is set in the AGC circuit section. By setting as, it is possible to prevent unnatural volume change when making a call, unnatural volume change when receiving a call, and unnatural volume change when the microphone mute operation is performed during a call. It is possible to prevent unnatural volume changes even at times.

[0028]

As described above, according to the first aspect of the present invention.
According to the method, a telephone line is connected to the primary side of the transformer, and the received voice is provided between the secondary side of the transformer and the speaker that reproduces the received voice signal as an acoustic output and the microphone that collects the transmitted voice signal. Equipped with automatic gain adjusting means and echo canceling means for performing echo canceling processing, which keep the levels of the signal and the transmitted voice signal appropriately, and operates as a full-duplex speakerphone, but when the microphone is muted, the echo canceller does not work, In the telephone device that operates as a half-duplex speakerphone by holding the automatic gain adjustment means on the receiving side with the amount of gain at that time, mutes the microphone when making a call to the telephone line and turns off the automatic gain adjustment means on the receiving side. However, since the automatic gain adjusting means includes a control means for setting a fixed gain value as a set value, It is possible to realize a speaker phone there is no change in the natural change in volume and earpiece volume.

According to a second aspect of the present invention, the control means turns off the automatic gain adjusting means on the receiving side as it is after receiving the RBT after transmitting the dial signal, and sets a fixed gain value to the automatic gain adjusting means. When the polarity inversion detection means is used to detect the polarity inversion, the reception side automatic gain adjustment means is turned on and the microphone mute is released to enable the call. Since it is controlled so that R after dial transmission at the time of calling
Even when receiving BT, it is possible to realize a speakerphone that does not cause an unnatural change in volume or a change in received volume.

Further, according to claim 3, the telephone line is connected to the primary side of the transformer, the secondary side of the transformer, the speaker for reproducing the received voice signal as an acoustic output, and the transmitted voice signal are collected. It is equipped with an automatic gain adjusting means for keeping the levels of the received voice signal and the transmitted voice signal properly and an echo canceling means for performing echo canceling between the microphone and the microphone. When muted, the echo canceller does not work, and in the telephone device that operates as a half-duplex speakerphone by holding the automatic gain adjustment means on the receiving side with the amount of gain at that point, when the incoming call is received from the telephone line, the automatic gain adjustment on the receiving side is performed. Since the control means for turning off the means and setting a fixed gain value as a set value in the automatic gain adjusting means is included, It is possible to realize a speaker phone there is no change in the natural change in volume and earpiece volume.

According to a fourth aspect of the present invention, the control means uses a means for counting the passage of a fixed time after the arrival of a call, and after the fixed time has passed, the receiving side automatic gain adjusting means is turned on and the microphone mute is released. However, since it is controlled so that the call can be made, if the fixed time is the time that is not affected by the line current that suddenly flows to the primary side of the transformer when the line is closed, the line will be closed when a call is received. It is possible to realize a speakerphone that does not have an unnatural volume change due to the influence of or the fluctuation of the listening volume, and if that time is extended to the time when data download is detected, even when muting the microphone for data download, It is possible to realize a speakerphone that does not have an unnatural volume change or a change in the listening volume.

Further, according to claim 5, the telephone line is connected to the primary side of the transformer, the secondary side of the transformer, the speaker for reproducing the received voice signal as an acoustic output, and the transmitted voice signal are collected. An automatic gain adjusting means for keeping the levels of the received voice signal and the transmitted voice signal properly, an echo canceling means for performing an echo canceling process, and an operating means for performing a mute operation of the microphone are provided between the microphone and the microphone. Although it operates as a speakerphone, the echo canceller does not work when the microphone is muted, the automatic gain adjustment means on the receiving side is held by the gain amount at that time, and the telephone device operates as a half-duplex speakerphone, during a call, In response to the microphone mute operation in the operation means, the automatic gain adjustment means on the receiving side is turned off, and this automatic gain adjustment is performed. Because it contains a control means for setting a set value of fixed gain value adjusting means, a microphone mute operation is unnatural volume changes and earpiece volume speakerphone no variation of even be realized during a call.

According to a sixth aspect of the present invention, the control means releases the microphone mute and turns on the receiving side automatic gain control means in response to the microphone mute release operation performed after the microphone mute operation during a call. Since the call is controlled to be in a callable state, it is possible to realize a speakerphone that does not cause an unnatural volume change or a change in the listening volume when the microphone mute operation is performed and then released during the call.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system according to a first embodiment of this invention.

FIG. 2 is a flowchart when operating as a speakerphone.

FIG. 3 is a flowchart when operating as a speakerphone.

[Explanation of symbols]

1 telephone network 11 Speakerphone call circuit (modem section) 24 telephone equipment

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Claims (6)

(57) [Claims] 1. A telephone line is connected to a primary side of a transformer, and a receiving side is provided between a secondary side of the transformer and a speaker which reproduces a receiving voice signal as an acoustic output and a microphone which collects a transmitting voice signal. An automatic gain adjusting means and an echo canceling means for performing an echo canceling process for properly maintaining the levels of the voice signal and the transmitted voice signal, respectively,
Although it operates as a full-duplex speakerphone, the echo canceller does not work when the microphone is muted, and the automatic gain adjusting means on the receiving side is held by the gain amount at that time, and the telephone device operates as a half-duplex speakerphone.
While muting the microphone when calling to the telephone line,
A telephone device comprising a control means for turning off the automatic gain adjusting means on the receiving side and setting a fixed gain value as a set value in the automatic gain adjusting means. 2. The control means according to claim 1, when the RBT is received after the dial signal is transmitted, the automatic gain adjusting means on the receiving side is turned off, and a fixed gain value is set to the automatic gain adjusting means. When the polarity reversal detection means is used to detect the polarity reversal, the automatic gain adjustment means on the receiving side is turned on after the fixed time has elapsed, and the microphone mute is released to enable the call. A telephone device characterized by being controlled to. 3. A telephone line is connected to the primary side of the transformer, and the receiving side is connected between the secondary side of the transformer and a speaker for reproducing the received voice signal as an acoustic output and a microphone for collecting the transmitted voice signal. An automatic gain adjusting means and an echo canceling means for performing an echo canceling process for properly maintaining the levels of the voice signal and the transmitted voice signal, respectively,
Although it operates as a full-duplex speakerphone, the echo canceller does not work when the microphone is muted, and the automatic gain adjusting means on the receiving side is held by the gain amount at that time, and the telephone device operates as a half-duplex speakerphone.
A telephone device comprising a control means for turning off the automatic gain adjusting means on the receiving side when an incoming call is received from a telephone line and setting a fixed gain value as a set value in the automatic gain adjusting means. 4. The control means according to claim 3, wherein the control means uses means for counting the passage of a fixed time after the arrival of an incoming call, and turns on the receiving side automatic gain adjusting means after the passage of the fixed time.
A telephone device in which the microphone mute is released and control is performed so that a call is possible. 5. A telephone line is connected to the primary side of the transformer, and the receiving side is connected between the secondary side of the transformer and a speaker for reproducing the received voice signal as an acoustic output and a microphone for collecting the transmitted voice signal. The automatic gain adjusting means for keeping the levels of the voice signal and the transmitted voice signal proper, the echo canceling means for performing the echo canceling processing, and the operating means for performing the mute operation of the microphone are provided and operate as a full-duplex speakerphone. When the microphone is muted, the echo canceller does not work, and in the telephone device that operates as a half-duplex speakerphone by holding the automatic gain adjustment means on the receiving side with the gain amount at that time, the microphone mute operation is performed by the operation means during a call. In response to this, the automatic gain adjustment means on the receiving side is turned off, and a fixed gain is set in this automatic gain adjustment means. A telephone device comprising a control means for setting a value as a set value. 6. The control means according to claim 5, wherein the microphone mute is released and the reception side automatic gain control means is turned on in response to the microphone mute release operation being performed after the microphone mute operation during a call. A telephone device characterized by being controlled so as to be in a callable state.