JPH118667A - Portable communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable communication equipment where a noise level at a high sound frequency is surely reduced through noise elimination. SOLUTION: The communication equipment is configured with a transmission microphone 106 that picks up at least the user voice, a reception section 102 that processes a signal received from an antenna 101, a receiver use speaker 105 that converts the received voice signal processed by the reception section 102 into a voice, a 2nd microphone 105 that is placed in the vicinity of the receiver speaker 105 and picks up sound around the receiver speaker, and a noise elimination circuit that uses the voice signal from the 2nd microphone 103 to eliminate noise as to the received voice signal to be transduced by the receiver speaker 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable communication device, and more particularly to a portable communication device capable of surely reducing a noise level in a high frequency range by removing noise.

[0002]

2. Description of the Related Art Conventionally, portable communication devices such as portable telephones have been considered to be used in various environments. In particular, the difficulty of hearing sounds caused by noise around the portable communication device is a serious problem. there were.

In order to cope with this, conventionally, there has been adopted a technique of providing a noise elimination circuit using sound obtained by a microphone for a transmitter and canceling the surrounding noise.

[0004]

However, in the above-mentioned conventional portable communication device, the speaker for the receiver and the microphone for the transmitter are generally set apart from each other. Depending on the physical distance,
In particular, there is a problem that the noise removal effect is low with respect to noise in a high-tone range.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a portable communication device capable of surely reducing a noise level in a high frequency range by removing noise. To provide.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem by collecting sounds around a speaker for a receiver and removing the noise by using the collected sounds.

That is, according to the invention of claim 1 of the present application, a microphone for a transmitter that collects at least a user's voice, a receiving unit that processes a signal received from an antenna, and a signal that is processed by the receiving unit A receiver speaker for converting a received voice signal into voice, a second microphone for collecting sound around the receiver speaker, and a second microphone for receiving voice signals to be converted by the receiver speaker.
A portable communication device comprising: a noise removal circuit that removes noise using a voice signal from a microphone.

[0008] The invention described in claim 2 of the present application is:
The mobile communication device according to claim 1, wherein the second microphone is installed near the receiver speaker.

The invention described in claim 3 of the present application provides
The said 2nd microphone is installed so that directions other than the direction with the highest directivity which the speaker for a receiver have may become the direction with the highest directivity which the said 2nd microphone has. 2. The mobile communication device according to item 2.

Further, the invention according to claim 4 of the present application is characterized in that the second microphone is installed on a back surface opposite to the surface on which the receiver speaker is installed. 3. The portable communication device according to 1 or 2.

According to the first or second aspect of the present invention, the sound around the handset speaker is collected by the second microphone installed near the handset speaker, and the noise removing circuit is provided. Then, noise is removed from the received voice signal to be converted by the receiver speaker using the voice signal from the second microphone. As described above, since the noise is removed by using the audio signal from the second microphone having a short physical distance from the receiver speaker, the noise level in the high-frequency range, which has little effect conventionally, can be reduced.

According to the third aspect of the present invention, a direction other than the highest directivity of the handset speaker is the direction of the highest directivity of the second microphone. Claim 4
According to the invention described in (1), it is desirable that the second microphone be installed on the back surface opposite to the surface on which the receiver speaker is installed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a portable communication device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of a portable communication device according to an embodiment of the present invention. As shown in the figure, the portable communication device of the present embodiment includes an antenna 101, a receiving unit 102 for processing a signal received from the antenna, and a receiver for converting a received voice signal processed by the receiving unit 102 into a voice. Speaker 105, a transmitter microphone 106 that collects the voice of the user, and a noise reduction microphone (second microphone) that is installed near the receiver speaker 105 and that collects the sound around the receiver speaker 105. 103, an active noise reduction circuit (noise removal circuit) 104 for removing noise from a received voice signal to be converted by the receiver speaker 105 using a voice signal from the noise reduction microphone 103, and a transmitter microphone 106. Signal processing of the uttered user's utterance and antenna 1 Is constituted by a transmission unit 107 that transmits through the 1.

FIG. 2 shows an example of a specific circuit configuration of the active noise reduction circuit 104 used in the portable communication device of the present embodiment.

In FIG. 1, an active noise reduction circuit 104 includes an operational amplifier 201 and resistors 202 to
205. That is, the operational amplifier 2
The audio signal from the noise reduction microphone 103 is connected to the (−) input terminal of the amplifier 01 via the resistor 202, and the received audio signal processed by the receiving unit 102 is input to the (+) input terminal of the operational amplifier 201. , The received audio signal potential with respect to the ground potential is divided by resistors 202 and 203 as a potential. The output signal of the operational amplifier 201, which is a noise reduction audio signal, is fed back to the (-) input terminal via the resistor 204.

Here, the voice signal from the noise reduction microphone 103 is vn, and the received voice signal is v
Assuming that r is the resistance of the resistor 202, R1 is the resistance of the resistor 203, R2 is the resistance of the resistor 203, Rc is the resistance of the resistor 203, and Rf is the resistance of the resistor 204, the noise reduction audio signal v is given by the following equation (Equation 1). Given by

## EQU1 ## v = (R1 + Rf) Rc / (R2 + Rc) R1
Vr-Rf / R1.vn If R1 = R2 and Rf = Rc, v = Rf / R1 (vr-vn) (Equation 1). From the received voice signal vr, the noise reduction microphone 103 Is output as the noise reduction audio signal v.

Next, FIG. 3 is a structural diagram for explaining a position where main components are installed in the portable communication device of the present embodiment.

As shown in FIG. 1, generally, in a portable communication device 301, a speaker 1 for a receiver is provided above a surface of the device.
In FIG. 5, a transmitter microphone 106 is provided below, and a liquid crystal display unit, an input key unit, and the like are provided between the receiver speaker 105 and the transmitter microphone 106.

In the portable communication device of the present embodiment, the noise reduction microphone 103 is provided on the back surface opposite to the front surface on which the receiver speaker 105 is provided. As described above, by installing the noise reduction microphone 103 at a physically short position near the receiver speaker 105, the noise reduction microphone 103 can reliably collect sound around the receiver speaker 105. Can be. In particular, when the noise reduction microphone 103 is installed on the back surface opposite to the front surface on which the receiver speaker 105 is installed as in the present embodiment, the user's face is placed on the installation surface of the receiver speaker 105. Because the ears are put on,
It can be imagined that the sound around the receiver speaker 105 can be collected more reliably.

The voice signal collected by the noise reduction microphone 103 is supplied to an active noise reduction circuit 104 formed on a circuit board in the portable communication device 301, and the voice signal generated by the noise reduction microphone 103 is supplied to the active noise reduction circuit 104. A noise reduction audio signal from which noise has been removed using the signal is supplied to the receiver speaker 105.

As described above, in the portable communication device of the present embodiment, the sound around the receiver speaker 105 is collected by the noise reduction microphone 103 installed near the receiver speaker 105, and the active noise reduction is performed. In the circuit 104, the noise is removed by using this, so that the noise level in the high-frequency range, which had little effect conventionally, can be surely reduced.

In the above description, the installation position of the noise reduction microphone 103 is opposite to the surface 401a on which the receiver speaker 105 is installed, as shown in FIG. Although installed on the back surface 401b, the present invention is not limited to this, and the same effect can be obtained by installing the device near the receiver speaker 105, such as the upper surface 401c and the side surfaces 401d and 401e.

[0024]

As is apparent from the above description, according to the present invention, the sound around the handset speaker is collected by the second microphone installed near the handset speaker. For a received voice signal to be converted by a receiver speaker, noise is removed using a voice signal from a second microphone, and a voice signal from a second microphone having a short physical distance from the receiver speaker is used. Since the noise is removed in this manner, it is possible to provide a portable communication device that can surely reduce the noise level in a high-frequency range, which has little effect in the related art.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a portable communication device according to an embodiment of the present invention.

FIG. 2 is a specific circuit configuration of an active noise reduction circuit used in the mobile communication device of the embodiment.

FIG. 3 is a structural diagram illustrating positions where main components are installed in the mobile communication device according to the embodiment.

FIG. 4 is an explanatory diagram illustrating candidates for installation positions of a noise reduction microphone.

[Explanation of symbols]

Reference Signs List 101 antenna 102 receiving unit 103 noise reduction microphone (second
Microphone) 104 Active noise reduction circuit (noise removal circuit) 105 Receiver speaker 106 Transmitter microphone 107 Transmitter 201 Operational amplifier 202 to 205 Resistance 301 Portable communication device 401a Receiver speaker installation surface 401b to 401e Installation position of noise reduction microphone Candidate

Claims (4)

[Claims] A microphone for a transmitter that collects at least a user's voice; a receiving unit that processes a signal received from an antenna; a speaker for a receiver that converts a received voice signal processed by the receiving unit into a voice. A second microphone that collects sounds around the receiver speaker; and a noise removal circuit that removes noise using a voice signal from the second microphone for a received voice signal to be converted by the receiver speaker. A portable communication device comprising: 2. The mobile communication device according to claim 1, wherein the second microphone is installed near the handset speaker. 3. The second microphone is installed such that a direction other than the highest directivity of the handset speaker is the highest directivity of the second microphone. Claim 1 or 2
A portable communication device according to claim 1. 4. The portable communication device according to claim 1, wherein the second microphone is provided on a back surface opposite to a surface on which the handset speaker is provided.