JP2001285410A - Cordless telephone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cordless telephone system which can suppress the unnatural sound volume change caused by the closed telephone circuit without using a polarity inversion detecting circuit. SOLUTION: When a call is made, this cordless telephone system performs RBT detection and initializes a speaker telephone by means of a speaker telephone speaking circuit 11 by an instruction from a control section 5 in accordance with the detected RET. When an incoming call arrives, the telephone system detects the completion of the connection of a radio channel between a master set 24 and a slave set 101 and initializes the speaker telephone by an instruction from the control section 5 in accordance with the trigger detected when the connection is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for reproducing a received voice signal input from a telephone line as a sound output from a speaker and simultaneously transmitting a transmitted voice signal collected by a microphone to the telephone line. The present invention relates to a cordless telephone device that enables heavy hands-free communication.

[0002]

2. Description of the Related Art In recent years, telephone apparatuses have come to have a speakerphone function capable of making a telephone call without having a telephone receiver. Since the speakerphone function normally converts the received voice signal into an acoustic signal and reproduces the sound from the speaker, when the received voice signal reproduced from the speaker reaches the microphone for collecting the transmitted voice signal, howling occurs. Can occur. By using an echo canceller, this howling is prevented, and a more natural full-duplex speakerphone is possible.

A telephone device having a speakerphone function also needs to maintain an appropriate level of a received voice signal that is reproduced from a speaker.
The optimization is performed by the C circuit. There is also a half-duplex speakerphone that does not have an echo canceller, but this is a system in which a call is switched by switching between transmission and reception.

[0004]

However, in a telephone device having a speakerphone function, when a line is closed by a line closing circuit at the time of an incoming call, a line current suddenly flows to the primary side of the transformer, and the line current of the transformer is reduced. Large pulse noise is generated on the secondary side. When this noise is input to the reception AGC circuit, the reception AGC circuit makes the gain extremely small and adjusts the output for large noise to be within an appropriate level. Further, the operation of the automatic gain adjustment has a characteristic that, although it responds instantaneously in the direction of suppressing the increase in volume, the operation in the direction of increasing the volume is slow. Therefore, such a characteristic is preferable to suppress the increase in volume, but if the recovery takes a long time after the gain becomes extremely small due to the large pulse-like noise generated in the transformer, it will be immediately after the speakerphone call starts. There is a problem that the received voice sound reproduced from the speaker is low at first, and the volume gradually becomes appropriate over time, which is unnatural.

[0005] Even when a call is made, the volume reproduced from the speaker when the telephone line is closed by pressing the speakerphone key on the operation unit changes the polarity of the line voltage when the other party's telephone line is closed. Since the direction of the current flowing to the primary side changes abruptly, the above-mentioned problem similarly occurs.

[0006] For this reason, regarding the volume change due to the polarity reversal noise generated when such a telephone line is closed,
The polarity inversion detection circuit is provided to detect the polarity inversion and then set the speakerphone device, thereby preventing the above-described problem from occurring.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cordless telephone device capable of suppressing an unnatural change in volume caused by closing a telephone line without using a polarity inversion detecting circuit.

[0008]

In order to achieve the above object, a cordless telephone device according to the present invention is connected to a telephone line, and has an automatic gain for properly maintaining the levels of a received voice signal and a transmitted voice signal. A cordless telephone comprising: a base unit having an adjusting unit and an echo canceling unit for performing an echo canceling process; and a slave unit connected to the base unit via wireless and having a speakerphone key input unit for operating a speakerphone function. In the apparatus, the parent device includes a ringback tone detection unit that detects a ringback tone, and a control unit that controls operations of the automatic gain adjustment unit and the echo cancellation unit,
If the end of the ringback tone is detected by the ringback tone detecting means when making a call to the telephone line, the control means sets the operations of the automatic gain adjusting means and the echo canceling means in a preset state. It is characterized by.

According to a second aspect of the present invention, in the cordless telephone apparatus according to the first aspect, when the end of the ring back tone is detected by the ring back tone detecting means, the control means sets a predetermined time. The operation of the automatic gain adjusting means and the operation of the echo canceling means is set to a preset state after the weight is reduced.

According to a third aspect of the present invention, in the cordless telephone apparatus according to the first or second aspect, the master unit detects connection completion of a wireless line in response to an input operation by the speakerphone key input means. When the wireless detection unit detects the completion of connection of the wireless line at the time of an incoming call from the telephone line, the control unit presets the operations of the automatic gain adjustment unit and the echo cancellation unit. It is characterized by being in a state.

According to a fourth aspect of the present invention, in the cordless telephone apparatus according to any one of the first to third aspects, when the wireless detection means detects the completion of the connection of the wireless line, the control is performed. After the means waits for a preset time, the operations of the automatic gain adjusting means and the echo canceling means are brought into a preset state.

According to a fifth aspect of the present invention, in the cordless telephone apparatus according to any one of the first to fourth aspects, the preset state is an initial state.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an internal configuration of a base unit of a cordless telephone device according to an embodiment of the present invention.

In FIG. 1, a base unit 24 of the cordless telephone device is connected to a telephone network 1 such as a public telephone network, and is connected to a primary side of a transformer 3 via a line closing circuit 2 for closing the line. Connected to. A hybrid circuit 4 is connected to the secondary side of the transformer 3, and sorts a received voice signal and a transmitted voice signal. The control unit 5 including a microcomputer or the like includes a line closing circuit 2, an operation unit (speaker phone key) 6, a speaker phone communication circuit (modem unit) 11,
It is connected to the radio unit 22 and the crosspoint SW circuit 23, and controls each unit according to a preset program. In addition, when a user (user) presses a key from the operation unit 6, the control unit 5 performs control to activate a function as a speakerphone.

The cross point SW circuit 23 is connected to 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 to the amplifier 7 via the hybrid circuit 4 from the secondary side of the transformer 3. The switching is performed for disconnection from the path of the transmitted voice signal. The speaker 21 of the main body and the microphone 2 are connected via the amplifiers 9 and 10.
0 or as an audio signal of the radio section 22.
The connection is switched to the wireless unit 22 via the communication devices 6 and 27.
The cross point SW circuit 23 is controlled by the control unit 5.

The amplifiers 7, 8, 9, 10, 26, 27
The transmission voice signal and the reception voice signal are electrically amplified.
The speakerphone communication circuit (modem unit) 11 outputs a transmission voice signal to the hybrid circuit 4 via the amplifier 7.
/ A converter 12, D / A converter 13 for outputting a received voice signal via amplifier 10, A / D converter 14 for receiving a received voice signal from amplifier 8, and transmission from amplifier 9. An A / D converter 15 for inputting an audio signal, a line-side echo cancellation circuit (LEC) 16 for removing a transmission audio signal component from the reception audio signal, and a reception audio signal component from the transmission audio signal Acoustic echo canceling circuit (AEC) 17 for removal, and transmission AGC circuit 18 and reception AGC circuit as automatic gain adjustment means for performing automatic gain adjustment so that the levels of the transmission voice signal and the reception voice signal are appropriate. 19.

The speakerphone communication circuit 11 is one digital signal processing semiconductor integrated circuit, and performs signal processing on a transmission voice signal and a reception voice signal, echo cancellation, automatic gain adjustment (hereinafter, referred to as "AGC"), and tone detection. And a ringback tone (hereinafter referred to as “RBT”) is detected without adding any parts. Although not shown, the speakerphone communication circuit 11 includes a tone transmitting unit and a tone detecting unit, and detects a tone by performing frequency analysis of a signal input as a received voice signal from the amplifier 8. This tone detection function can detect not only a single tone but also a modulated signal.

The microphone 20 is connected to the cross point SW circuit 23 via the amplifier 9. Parent machine 24
Amplifies the transmission voice signal collected by the microphone 20 by the amplifier 9 and outputs the amplified signal via the cross point SW circuit 23 to A
The signal is input to the / D converter 15 and converted from an analog signal to a digital signal. The received voice signal is converted to a D / A converter 13.
The signal is amplified by the amplifier 10 via the cross point SW circuit 23, and reproduced as an audio output from the speaker 21.

The AEC 17 prevents the received voice reproduced as an audio output from the speaker 21 from being collected by the microphone 20 and transmitted together with the transmitted voice signal. The LEC 16 collects sound from the microphone 20 and outputs the hybrid circuit 4 via the cross point SW circuit 23.
Is amplified by the amplifier 8 as a voice signal on the receiving side and is prevented from wrapping around in a state converted from the A / D converter 14 into a digital signal.

The radio section 22 receives the voice signal of the other party transmitted from the telephone line network 1 via the cross point SW circuit 23 by the radio transmission circuit in the radio section 22, and transmits the FM signal to a predetermined carrier frequency. The signal is modulated and transmitted from the antenna 25 to the slave unit 101. Further, the radio unit 22 receives the FM modulation signal received by the antenna 25 by the radio reception circuit of the radio unit 22, demodulates the signal, and then cross-points the signal.
Output to the telephone network 1 via the W circuit 23. The communication control including the control of the transmission frequency and the reception frequency of the wireless unit 22 is generally performed by the control unit 5, but may be performed by a control unit (not shown) built in the wireless unit 22.

FIG. 2 is a block diagram showing the internal configuration of the slave unit of the cordless telephone device according to the embodiment of the present invention.

In FIG. 2, slave unit 101 is a portable unit connected to master unit 24 via radio. Slave device 101,
An operation unit (speaker phone key) 102, a control unit 103 connected to the operation unit 102, the control unit 103, and the wireless unit 1
05, etc., a radio unit 105 connected to the antenna 110, and a baseband unit 1
A speaker driver amplifier 106 connected to the speaker driver amplifier 04, a speaker 107 connected to the speaker driver amplifier 106 and outputting sound during a speakerphone, a receiver 108 connected to the baseband unit 104 and outputting sound,
It is composed of a microphone 109 that collects audio for amplifying the audio signal and outputs a microphone signal (audio signal), and an antenna 110. The control unit 103 controls the baseband unit 104 and the radio unit 105,
The operation processing is performed according to the operation input from the operation unit 102. When the speakerphone is used, the signal received from the antenna 110 is transmitted to the radio unit 105 and the baseband unit 10.
4 and output from the speaker 107 via the speaker driver amplifier 106 as audio.

FIG. 3 is a flowchart showing a control process of the control unit 5 and the control unit 103.

In FIG. 3, if an input operation is performed by pressing the speakerphone key from one of the operation units of master unit 24 or slave unit 101 (YES in step S201), a call signal from telephone line network 1 is received. It is determined whether or not the call signal has been received (step S202). When the call signal has been received (YES in step S202), the process proceeds to step S211. On the other hand, when the call signal has not been received (step S20).
2; NO), it is determined whether or not a dial tone (hereinafter referred to as “DT”) from the telephone line network 1 can be heard, that is, whether or not a call operation for the telephone line network 1 has been performed (step S203).

If the result of this determination is that a calling operation has not been performed (NO in step S203), step S20
On the other hand, if a call operation is being performed (YES in step S203), a call operation corresponding to the call operation is executed (step S204). After the calling operation is completed, the speakerphone communication circuit 11 detects whether or not the RBT is heard, that is, whether or not the RBT is detected (step S205), and the detection is continued as long as the RBT is heard (step S205). And YE
S). When RBT is no longer heard, ie RBT
Is no longer detected (N in step S205).
O), wait (standby) is executed for a preset time according to a command from the control unit 5 (step S207).
The determination of whether to perform the wait in step S206 may not be performed. Next, the speakerphone call circuit 1
In step 1, the speakerphone is initialized according to a command from the control unit 5 (step S208). As a result, the voice signal from the other party is input, the circuit of the voice signal on the own side is opened, and a call can be made (step S209), a call in a speakerphone state is formed, and this processing ends.

On the other hand, in step S211, it is determined whether the input operation by pressing the speakerphone key is the parent device 24 or the child device 101, and if the input operation is performed from the child device 101 (step S211). YES), it is determined whether the connection of the wireless line is completed (step S21).
2) The process is repeated until the connection of the wireless line is completed (NO in step S212). When the connection of the wireless line is completed (YES in step S212), it is determined whether or not to additionally wait, in consideration of the time required for the connection of the wireless line (step S213), and when the wait is not performed (step S213). (NO), while proceeding to step S208, if additional wait is to be performed (YES in step S213), a certain time suitable for the wait is waited (step S214), the process proceeds to step S208, and the command from the control unit 5 is issued as described above. Performs initialization processing of the speakerphone. In this initialization process, initialization settings suitable for the child device 101 can be made.

On the other hand, if the result of determination in step S211 is that the input operation has been performed from parent device 24 (NO in step S211), it is determined whether or not to wait (step S206). Step S20
6), polarity inversion noise generated when the line is closed,
Alternatively, a wait is performed for a predetermined time in consideration of noise or the like when the cross point SW circuit 23 is connected (step S207), and
If the process in step S208 is executed and the wait is not performed (NO in step S206), the process from step S208 is performed without waiting for a fixed time, and the process is terminated. In the present embodiment, both the speakerphone function of the base unit 24 and the speakerphone function of the slave unit 101 can be operated by the speakerphone communication circuit 11 provided in the base unit 24.

Next, the operation of the slave unit 101 when receiving an incoming call will be described with reference to FIG.

FIGS. 4A and 4B are time charts showing the operation of the slave unit 101 when receiving an incoming call. FIG. 4A shows a line transmitted from the telephone line network 1 to the cordless telephone device, and FIG. (C) shows a wireless line connected from the master unit 24 to the slave unit 101,
(D) shows a line connection in which the base unit 24 closes the line by the line connection circuit 2, and (e) shows a speakerphone process for setting the speakerphone communication circuit 11 of the base unit 24.

First, as shown in FIG. 4A, a CI signal is transmitted to a cordless telephone device, and a calling signal is transmitted from a base unit 24 to a slave unit 101 connected via a wireless line. As shown in FIG. 4B, when the speakerphone key of the operation unit 102 is pressed by the slave unit 101 (speakerphone key on), a wireless line is connected as shown in FIG. Path connection completed), and accordingly (d) of FIG.
The line connection operation is performed as shown in (1) (line connection). After detecting the completion of the wireless path connection as shown in FIG. 4 (e), the system waits for a certain period of time to perform speakerphone setting (speakerphone setting). Thus, as shown in FIG. 4A, the speakerphone circuit is set after the occurrence of the transient pulse-like noise generated by the polarity inversion (polarity inversion).

Next, the operation of the master unit 24 and the slave unit 101 at the time of transmission will be described with reference to FIG.

FIGS. 5A and 5B are time charts showing the operation of the base unit 24 and the handset unit 101 when making a call. FIG. 5A shows the line after the calling operation, and FIG. ,
(C) shows the RBT detection in the speakerphone communication circuit 11 and the control unit 5, and (d) shows the speakerphone processing for setting the speakerphone communication circuit 11 of the master unit 24.

As shown in FIG. 5A, when an RBT is transmitted, the RBT is detected. Next, as shown in FIG. 5B, when the other party answers (the answer of the other party).
As shown in FIG. 5C, it is detected that there is no RBT to come. As shown in FIG. 5D, the control unit 5
After waiting for a certain period of time, the speakerphone is set (speakerphone setting). As a result, as shown in FIG. 5A, the speakerphone circuit can be set after the occurrence of transient pulse-like noise caused by polarity inversion.

According to the present embodiment, at the time of transmission, RB
T is detected (step S205), and the detected RB
The speakerphone communication circuit 11 performs speakerphone initialization processing according to a command from the control unit 5 according to T (step S
208) At the time of an incoming call, the completion of the connection of the wireless line between the master unit 24 and the slave unit 101 is detected (step S212).
Since the speakerphone initialization process is performed according to a command from the control unit 5 in response to the detection of the trigger when the wireless line connection is completed (step S208), the polarity inversion detection circuit is not provided even in the cordless handset, and the telephone line is closed. , An unnatural change in volume caused by the

[0036]

As described above in detail, according to the cordless telephone set of the first aspect, the base unit detects the end of the ring back tone by the ring back tone detecting means when making a call to the telephone line. In this case, the control unit sets the operations of the automatic gain adjustment unit and the echo cancellation unit in a preset state, so that the polarity inversion detection circuit is not provided, and an unnatural volume change due to the closing of the telephone line can be suppressed. it can.

According to the cordless telephone apparatus of the present invention, when the ringback tone control means detects the end of the ringback tone, the control means waits for a preset time and then sets the automatic gain adjustment means and Since the operation of the echo canceling unit is set to a preset state, it is possible to protect against the occurrence of polarity inversion noise generated when the line is closed, noise generated when the cross point SW circuit is connected, and the like.

According to the third aspect of the present invention, when the wireless line detecting means detects the completion of the connection of the wireless line in response to the input operation by the speakerphone key input means at the time of an incoming call from the telephone line, the control means causes Since the operations of the automatic gain adjusting means and the echo canceling means are set in advance, the cordless handset is not provided with the polarity reversal detection circuit, so that an unnatural volume change due to the closing of the telephone line can be suppressed. .

According to the cordless telephone device of the present invention, when the wireless line detecting means detects the completion of the connection of the wireless line, the control means waits for a preset time, and then the automatic gain adjusting means and the echo canceling means. Since the operation of the means is set to a preset state, it is possible to protect against the occurrence of polarity inversion noise generated when the line is closed, noise generated when the cross point SW circuit is connected, and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal configuration of a base unit of a cordless telephone device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a slave unit of the cordless telephone device according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating a control process of a control unit 5 and a control unit 103;

4A and 4B are time charts showing the operation of the slave unit 101 at the time of an incoming call, FIG. 4A shows a line transmitted from the telephone line network 1 to the cordless telephone device, and FIG. 102 shows the operation of the slave unit 102, (c) shows a wireless line connected from the master unit 24 to the slave unit 101, and (d) shows a line in which the master unit 24 closes the line by the line closing circuit 2. (E) shows a speakerphone process for setting the speakerphone communication circuit 11 of the master unit 24.

FIGS. 5A and 5B are time charts showing the operation of the base unit 24 and the mobile unit 101 at the time of calling, where FIG. 5A shows a line after a calling operation, FIG. ) Shows the RBT detection in the speakerphone call circuit 11 and the control unit 5, and (d) shows the speakerphone call circuit 11 in the base unit 24.
Is shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Telephone network 5,103 Control part 6,102 Operation part 11 Speaker phone communication circuit 23 Cross point SW circuit 24 Master 101 Child

Claims (5)

[Claims] A master unit connected to a telephone line, comprising: an automatic gain adjustment unit for maintaining appropriate levels of a reception voice signal and a transmission voice signal, and an echo cancellation unit for performing echo cancellation processing, and the master device. A cordless telephone device that is connected to a wireless device and has a speakerphone key input unit that operates a speakerphone function, wherein the base unit device includes a ringback tone detection unit that detects a ringback tone; Control means for controlling the operation of the automatic gain adjusting means and the echo canceling means, and when the end of the ringback tone is detected by the ringback tone detecting means during transmission to the telephone line, the control means Sets the operations of the automatic gain adjustment means and the echo cancellation means to a preset state. A cordless telephone device characterized in that: 2. When the end of the ringback tone is detected by the ringback tone detecting means, the control means waits for a preset time and then controls the operations of the automatic gain adjusting means and the echo canceling means. 2. A state set in advance.
Cordless telephone device as described. 3. The master device includes a wireless detection unit that detects connection completion of a wireless line in response to an input operation by the speakerphone key input unit, and the wireless detection unit detects the wireless connection when an incoming call is received from the telephone line. 3. The cordless telephone device according to claim 1, wherein when the completion of the line connection is detected, the control unit sets the operations of the automatic gain adjustment unit and the echo cancellation unit to a preset state. 4. When the wireless detecting means detects the completion of connection of the wireless line, the control means waits for a preset time and then sets the operations of the automatic gain adjusting means and the echo canceling means in advance. The cordless telephone device according to any one of claims 1 to 3, wherein the cordless telephone device is set in a state in which the cordless telephone is in a state of being set. 5. The cordless telephone device according to claim 1, wherein the preset state is an initial state.