JPH11284715A - Hand-free type portable telephone terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable telephone terminal equipment capable of giving optimum echo return loss E.R.L. to an echo cancellation circuit even when a vehicle or a mount position differs. SOLUTION: In the case of attaching this terminal equipment 20 to a vehicle, the terminal equipment is initialized. An initial setting state signal is given to an initial setting signal input 24 of a microcomputer 25. Upon the receipt of the signal, the microcomputer 25 replaces an output of a speaker amplifier 26 with an output of a reference voice generating source 22. The output is picked up by a microphone 4, a microphone input is rectified by a full wave rectifier circuit 23 and the rectified signal is applied to an A/D input of the microcomputer 25. The microcomputer 25 variably controls a gain of a microphone input adjustment section 27 in response to an output level of the full wave rectifier circuit 23 to set the optimum E.R.L. value to an echo cancellation circuit 21a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hands-free type portable terminal device, and more particularly to an echo canceling operation of the same unit by varying a gain from a speaker output to a microphone input, regardless of a vehicle. The present invention relates to a hands-free type mobile terminal device that has improved satisfactorily.

[0002]

2. Description of the Related Art A hands-free portable telephone terminal device 1 shown in FIG. 2 is a portable telephone terminal 2 in which a hands-free unit comprising a hands-free adapter 3, a microphone 4 and a speaker 5 is assembled. The microphone 4 and the speaker 5 are connected to the hands-free adapter 3 having a built-in charger through dedicated connection cables. Generally, the speaker 5 is fixed to the passenger seat side, and the microphone 4 is connected to the sun visor on the driver's seat side and set in the passenger compartment.

[0003] When a call is made, the voice of the driver is extended from the microphone 4 to the voice of the other party via the speaker 5 into the passenger compartment. However, unlike the case where a telephone call is directly made with the receiver of the mobile phone terminal 2, the voice of the other party expanded into the vehicle interior from the speaker 5 is collected by the microphone 4 and transmitted to the other party again, and is sent to the other party as an acoustic echo There was a problem of hearing and giving discomfort.

In order to eliminate such echoes,
As shown in FIG. 3, the conventional hands-free type mobile phone terminal device 1 has a configuration in which an echo canceling unit 7 is built in. The echo canceling unit 7 has a microphone input terminal Tm and a receiving input terminal Tr, and supplies them to a mobile phone terminal transmitting terminal Tt and a speaker output terminal Ts via an amplifier circuit 8 and a speaker amplifier 9, respectively.

The microphone input and the reception input are supplied to the echo cancel circuit 7a via the amplifier circuits 7m and 7r in the echo cancel unit 7, respectively. The echo cancel circuit 7a passes through the speaker input for the reception input and sends it to the speaker amplifier 9, and the microphone input is a value indicating the difference between the microphone input and the reception input optimal for echo cancellation which is set in advance. R. L (Echo Retur
The received input is subtracted based on the (n Loss) value, and the acoustic echo is canceled and output to the amplifier circuit 8 to cancel the echo.

[0006]

In the above-mentioned conventional hands-free type portable telephone terminal device 1, the reception input collected by the microphone 4 and included in the transmission output is converted from the microphone input by the echo cancellation circuit 7a. Subtracting and canceling out echo cancellation.

However, E.I. R. The L value is not always the optimum value depending on the difference in the vehicle or the mounting position. If the transmission / reception is performed in that state, howling or the like occurs, and sufficient echo cancellation cannot be performed.

For this reason, in order to make full use of the echo canceling function, the E.E. R. There was a problem that the L value had to be changed.

Therefore, the present invention has been made in order to solve the above-mentioned problems. Therefore, even if the vehicle or the mounting position is different, the optimum E.C. R. It is an object of the present invention to provide a hands-free mobile phone terminal device that can be given an L value.

[0010]

SUMMARY OF THE INVENTION Accordingly, in order to achieve the above object, the present invention provides a method of receiving a microphone input from a microphone and a reception input of a portable telephone terminal, and canceling the reception input included in the microphone input. An echo canceling unit that transmits and outputs a speech to the mobile phone terminal, a speaker amplifier that outputs a reception input of the mobile phone terminal to a speaker, and a pseudo voice of the reception input that is output as an initial setting when the vehicle is mounted, as the microphone input. A gain control unit for detecting and variably controlling the gain of the microphone input input to the echo canceling unit according to the size of the microphone input.

The present invention also provides a reference sound output unit for outputting, via a speaker, a pseudo sound serving as a reference for obtaining an optimum difference between a microphone input and a reception input, and the echo canceling unit. And a full-wave rectifier circuit for inputting the pseudo-voice output from the speaker as a microphone input through a microphone, and performing full-wave rectification on the microphone input. A control circuit for variably controlling the gain of the microphone input to be input to the echo canceling unit in response thereto, and a variable gain amplifier circuit for varying the gain of the microphone input in multiple stages according to the output from the control circuit. It is characterized by the following.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a hands-free type portable telephone terminal according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a hands-free portable telephone terminal according to the present invention. As shown in FIG. 1, the hands-free type mobile phone terminal device 20 receives the microphone input from the microphone 4 and the reception input of the mobile phone terminal, cancels the reception input included in the microphone input, and sends the same to the mobile phone terminal. An echo canceling unit 21 for outputting a speech, and a speaker 5 for receiving a speech input of a mobile phone terminal.
And a pseudo-voice of a reception input output as an initial setting when the vehicle is mounted is detected as a microphone input, and a microphone input to be input to the echo canceling unit 21 according to the size of the microphone input. And a gain control unit 28 for variably controlling the gain.

The echo canceling section 21 has a transmission output terminal Tt and a reception input terminal Tr, supplies a speaker output to a speaker output terminal Ts via a speaker amplifier 26, and outputs a microphone via a gain control section 28. A microphone input is supplied from the input terminal Tm.

The reception input is transmitted to the echo canceling circuit 21 via the amplifier circuit 21r in the echo canceling section 21.
a. The transmission output is supplied from the echo cancellation circuit 21a to the transmission output terminal Tt via the amplifier circuit 21t in the echo cancellation unit 21. The echo cancel circuit 21a passes through the reception input and sends it to the speaker amplifier 26.
The E.C. set in the echo cancellation circuit 21a by the gain control unit 28. R. The reception input is subtracted based on the L value, and the echo is canceled by canceling the acoustic echo and outputting the result to the amplifier circuit 21t.

The gain control unit 28 specifically has an optimum E.C. R. A reference audio output unit 22 for outputting a pseudo audio serving as a reference for obtaining the L value via the speaker 5, and a pseudo audio output from the speaker 5 and provided at a stage preceding the echo cancellation circuit 21 a in the echo cancellation unit 21. Is input as a microphone input via the microphone 4, and the microphone input is input to the echo canceling circuit 21a in accordance with the magnitude of the output of the full-wave rectifier circuit 23 for full-wave rectification of the microphone input. And a microphone input adjusting unit 27 which is a variable gain amplifier circuit that varies the gain of the microphone input in multiple stages in accordance with the output from the microcomputer 25. I have.

The microcomputer 25 increases the gain of the microphone input as the output of the full-wave rectifier circuit 23 decreases, and decreases the gain of the microphone input as the output of the full-wave rectifier circuit 23 increases.

The operation of the hands-free portable telephone terminal device 20 according to the present invention in such a configuration will be described.

First, a hands-free type mobile phone terminal device 2
When attaching 0 to the vehicle, perform initial settings. At this time,
The initial setting state signal is input to the microcomputer 25 as the initial setting signal input 2.
4 is input. Upon receiving the signal, the microcomputer 25 switches the output of the speaker amplifier 26 to the output of the reference sound generation source 22. The sound is collected by the microphone 4, and the microphone input is rectified by the full-wave rectifier circuit 23 and applied to the A / D input of the microcomputer 25. The microcomputer 25 variably controls the gain of the microphone input adjustment unit 27 in accordance with the output level of the full-wave rectifier circuit 23, so that the optimum E.C. R. L
The value is set in the echo cancellation circuit 21a. That is, when installed in a vehicle, if the output of the full-wave rectification circuit 23 is small, the gain of the microphone input is increased by the microphone input adjustment unit 27. Conversely, if the output of the full-wave rectification circuit 23 is large, the microphone input adjustment unit 27 is increased. Reduces the gain of the microphone input for optimum E.C. R. L value is echo cancellation circuit 21
is set to a.

[0020]

As described above, according to the hands-free mobile phone terminal of the present invention, the microphone input and the reception input of the mobile phone terminal are received, and the reception input included in the microphone input is canceled. The microphone input gain input to the echo cancellation circuit for transmitting and outputting the speech to the mobile phone terminal is set to E.E. R. L is adjusted so as to be an appropriate value. R. Each time the vehicle or mounting position changes, the E.L. R. There is no need to change the L value, and no adjustment of the device is required, and accurate echo cancellation can be performed with the same device without impairing the function of the echo cancellation operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a hands-free mobile phone terminal device according to the present invention.

FIG. 2 is a schematic configuration diagram illustrating an example of use of a hands-free mobile phone terminal device.

FIG. 3 is a block diagram showing a conventional example of a hands-free mobile phone terminal device.

[Explanation of symbols]

 Reference Signs List 20 hands-free type mobile phone terminal device 21 echo canceling unit 22 reference sound generating unit 23 full-wave rectifying circuit 25 microcomputer (control circuit) 26 speaker amplifier 27 microphone input adjusting unit 28 gain control unit

Claims (2)

[Claims] An echo canceling unit that receives a microphone input from a microphone and a reception input of a mobile phone terminal, cancels the reception input included in the microphone input, and outputs a transmission to the mobile phone terminal; A speaker amplifier that outputs a reception input to a speaker, and a pseudo-voice of the reception input that is output as an initial setting when the vehicle is mounted is detected as the microphone input, and is input to the echo canceling unit according to the size of the microphone input. A gain control unit for variably controlling the gain of the microphone input to be performed. 2. A gain control section comprising: a reference audio output section for outputting, via a speaker, a pseudo audio serving as a reference for obtaining an optimum difference between a microphone input and a reception input; And a pseudo-voice output from a speaker as a microphone input through a microphone, and a full-wave rectifier circuit for full-wave rectifying the microphone input; and the echo according to the magnitude of the output of the full-wave rectifier circuit. A control circuit for variably controlling the gain of the microphone input input to the cancel unit; and a variable gain amplifier circuit for varying the gain of the microphone input in multiple stages according to the output from the control circuit. The hands-free mobile phone terminal device according to claim 1.