JPH1065767A - Telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily make calling without being affected by ambient noise. SOLUTION: The voice of a caller is detected by a transmitter 2. A microphone 4 detects ambient noise. An opposite phase amplifier 5 inverting the phase of the output signal of the microphone 4. A mixing circuit 6 mixes a voice signal from the transmitter 2 and that from the amplifier 5. The components of noise in the voice signals is cancelled by mixing the speech signal from the transmitter 2 and that from the amplifier 5. On the other hand, a mixing circuit 7 mixes a signal from the amplifier 5 and a received voice signal from a voice signal processing circuit 8. Since the sound obtained by making the phases of a received voice and ambient noise opposite to each other is outputted from a receiver 3, noise infiltered to the ear of a callee is cancelled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone, and more particularly to a telephone capable of making a good call without being affected by ambient noise.

[0002]

2. Description of the Related Art In recent years, portable telephones and PHS (Personal Digital
Telephones such as a handy phone system) are widely used, but since these telephones are often used outdoors, there is a problem that transmission quality and reception quality are easily affected by ambient noise. .

[0003]

In other words, in these telephones, since the transmitter picks up ambient noise, a voice in which noise is mixed into the voice of the transmitter is transmitted. There is a problem that it is necessary to distinguish only the voice of the sender from the voice of the receiver mixed with noise. In addition, there is a problem that the receiver needs to distinguish only the sound of the receiver from the surrounding noise that enters the ear.
The present invention has been made to solve the above problems,
An object of the present invention is to provide a telephone capable of making a good call without being affected by ambient noise.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a transmitter for detecting a speaker's voice, a microphone for detecting ambient sound, and a phase for inverting a phase of an output signal of the microphone. It has an inverting amplifier circuit and a mixing circuit for transmitting a signal obtained by mixing a voice signal from a transmitter and a signal from a phase inverting amplifier circuit to a telephone network. As described above, when the audio signal from the transmitter and the signal from the phase inversion amplifier are mixed by the mixing circuit, the ambient noise component detected by the transmitter and the noise component from the phase inversion amplifier are inverted. Because of the phase, noise components in the audio signal are canceled.

Further, a microphone for detecting ambient sounds, a phase inverting amplifier circuit for inverting the phase of an output signal of the microphone, a receiver for outputting voice to a receiver, and a telephone line network. And a mixing circuit for outputting to the receiver a signal obtained by mixing the audio signal of (1) with the signal from the phase inversion amplifier circuit. In this way, when the audio signal from the telephone line network and the signal from the phase inversion amplifier circuit are mixed by the mixing circuit, the receiver outputs a sound in which the received voice and the surrounding noise are in opposite phases, so that the receiver's voice is output. The surrounding noise that enters the ear is canceled.

[0006]

FIG. 1 is a block diagram of a telephone showing a first embodiment of the present invention, and FIG. 2 is an external view of the telephone. The telephone 1 of the present embodiment is a mobile phone or a PHS.
Mobile communication telephone. First, the operation on the transmitting side will be described. The sender's voice is detected by the transmitter 2 in the telephone 1 and converted into a voice signal.

On the other hand, the microphone 4 detects noise around the telephone 1 and converts the noise into an audio signal. The microphone 4 is disposed on the back side of the transmitter 2 and the receiver 3 provided in front as shown in FIG. 2 (a) in order to better pick up ambient noise and not to pick up the voice of the transmitter. (FIG. 2B). Furthermore, by lowering the sensitivity to the human voice frequency band, the voice of the sender is not picked up.

An antiphase amplifier 5 which is a phase inversion amplifier circuit
Inverts and amplifies the phase of the audio signal output from the microphone 4. Subsequently, the mixing circuit 6 mixes the audio signal output from the transmitter 2 and the audio signal output from the antiphase amplifier 5.

The audio signal processing circuit 8 encodes the audio signal output from the mixing circuit 6 and
Modulates the output signal of the audio signal processing circuit 8 and
Output to 0. As a result, the radio wave transmitted from the antenna 10 is received by a wireless base station (not shown), and the wireless base station makes a line connection to a telephone network via an exchange or the like.
Thus, the voice from the telephone 1 is transmitted to the telephone of the receiver connected to the telephone line network or the like.

As described above, when the voice signal from the transmitter 2 and the signal from the antiphase amplifier 5 are mixed, the ambient noise component detected by the transmitter 2 and the noise from the antiphase amplifier 5 are mixed. Since the components are out of phase with each other, ambient noise components in the audio signal are canceled. Therefore, it is possible to improve the ratio of the voice level of the sender to the noise level, transmit clear voice with less noise to the receiver side, and improve the transmission quality.

Next, the operation of the receiver will be described. The transmission / reception circuit 9 demodulates the radio wave from the wireless base station received by the antenna 10, and the audio signal processing circuit 8 decodes the output signal of the transmission / reception circuit 9. Then, the mixing circuit 7 mixes the signal obtained from the antiphase amplifier 5 and the audio signal output from the audio signal processing circuit 8 in the same manner as described above.

As a result, the receiver 3 simultaneously outputs the received voice transmitted from the telephone on the side of the transmitter and a sound in which the surrounding noise is in an opposite phase. Will be countered. Therefore, the received voice can be heard with the surrounding noise reduced, and the received quality can be improved.

In this embodiment, a mobile phone or a PH
Although a mobile communication telephone such as S has been described as an example, it is needless to say that the invention may be applied to a home telephone fixed indoors.

[0014]

According to the present invention, by mixing the audio signal from the transmitter and the signal from the phase inversion amplifier circuit by the mixing circuit, the surrounding noise component in the audio signal can be canceled. Therefore, it is possible to improve the ratio of the voice level of the transmitter to the noise level, transmit clear voice with less noise to the receiver side, and improve the transmission quality.

Further, by mixing the voice signal from the telephone line network and the signal from the phase inversion amplifier circuit by a mixing circuit, it is possible to cancel the surrounding noise that enters the ear of the receiver, so that the surrounding noise is eliminated. , The reception voice can be heard, and the reception quality can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a telephone showing a first embodiment of the present invention.

FIG. 2 is an external view of the telephone shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... telephone, 2 ... transmitter, 3 ... receiver, 4 ... microphone, 5 ... antiphase amplifier, 6, 7 ... mixing circuit, 8 ... audio signal processing circuit, 9 ... transmission / reception circuit, 10 ... antenna.

Claims (2)

[Claims] 1. A transmitter for detecting a voice of a transmitter, a microphone for detecting ambient sound, a phase inversion amplifier circuit for inverting a phase of an output signal of the microphone, and a transmitter. And a mixing circuit for transmitting a signal obtained by mixing a voice signal from the amplifier and a signal from the phase inversion amplifier circuit to a telephone network. 2. A microphone for detecting ambient sounds, a phase inversion amplifier for inverting the phase of an output signal of the microphone, a receiver for outputting voice to a receiver, and a telephone line network. A mixing circuit for outputting to the receiver a signal obtained by mixing the voice signal and the signal from the phase inversion amplifier circuit.