JPH11164006A - Transmitter/receiver and portable communication terminal system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent acoustic echo or howling, to simplify the circuit configuration and to prevent the top of transmission voices from being cut concerning a hands-free talky. SOLUTION: This system has plural earphones 4 to be mounted in ears for outputting voices, a plug 2 connected to the earphone jack of a portable mobile communication terminal for extracting transmitted and received audio signals, a microphone 5 for collecting voices, an amplifier circuit 9 for amplifying the audio signals collected by the microphone 5, a volume circuit 11 for controlling the volume level of the microphone 5, an amplifier circuit 8 for received signals from the portable mobile communication terminal, and a volume circuit 10 for controlling the volume level of the received signals. Besides, a plurality of amplifier circuits 8 and a plurality of volumes 10 are provided corresponding to the plurality of earphones 4, and plural persons can simultaneously speak with the microphones 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a portable mobile communication terminal,
For example, the present invention relates to a handset that is used by being connected to a mobile phone radio or the like, and that can be mounted on an auricle to perform sending and receiving without using a hand, and a portable communication terminal system.

[0002]

2. Description of the Related Art There is a hands-free communication device as a conventional technology in which a plurality of persons simultaneously talk using one portable mobile communication terminal. This hands-free communication device has a speaker and a microphone, and is connected to a mobile communication terminal.
The receiving voice when making a call with the hands-free communication device is
A receiving voice signal of a mobile communication terminal is amplified and generated from a speaker so that a plurality of persons can hear the voice. On the other hand, the transmitted voice is collected by the microphone of the hands-free device and the sounds emitted by a plurality of persons and the environmental sound, and is output to the mobile communication terminal as a transmitted voice signal. This transmission voice signal is emitted to the antenna of the base station by radio at high frequency modulation by the mobile communication terminal, and the base station demodulates the received radio wave of the mobile communication terminal, which is a hands-free communication device,
It has a function that allows you to talk to the target partner terminal over a public line.

[0003] Therefore, as a general problem occurring in the hands-free communication device, there is an acoustic echo or howling caused by a microphone of the device picking up a received voice. As a means for solving this problem, a method of muting the microphone output when the received voice is output from the speaker, or a method of inputting a signal having the opposite phase to the received voice to the microphone output to prevent the above problem (echo canceller) It has been known.

[0004]

The microphone output mute method and the echo canceller method have a complicated circuit configuration and are expensive, and when a call is made by a plurality of persons, the transmitted voice tends to be cut off. When the terminal is changed, there is a problem that the terminal cannot be used due to a difference in input / output terminals or a difference in system.

However, in the conventional method, the circuit configuration is complicated and the apparatus is expensive. When a plurality of people talk, the transmitted voice tends to be cut off. There is a problem that it cannot be used if it changes.

To explain these problems in more detail, the causes of the above-described acoustic echo and howling are due to the configuration of the hands-free communication device. Specifically, a received voice is output from the speaker of the device,
Although the transmitted voice is collected by the microphone of the device, the microphone is easy to collect the received voice from the speaker because the speaker and the microphone are close to each other.

Further, if a method for muting the microphone output or an echo canceller, which is a means for solving this problem, is employed, the circuit becomes complicated and the apparatus becomes expensive.

[0008] Further, there are cases where the mobile communication terminal cannot be used depending on the portable mobile communication terminal to be connected, and even if the mobile communication terminal can be used, the versatility is low such that good call characteristics cannot be obtained due to a difference in the level of transmission and reception.

(Object of the Invention) It is an object of the present invention to provide an inexpensive handset which can be connected to a portable mobile communication terminal so that a plurality of persons can talk at the same time without hands (hands-free).

Another object of the present invention is to provide a highly versatile handset which does not select a type of portable mobile communication terminal.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and a hands-free type handset comprises a plurality of earphones which are attached to ears and output sound, and a portable mobile communication terminal. From a plug that can be connected to the earphone jack to take out audio signals transmitted and received, a microphone that collects audio, an amplifier circuit that amplifies the audio signal collected by the microphone, a volume circuit that adjusts the level, and a portable mobile communication terminal And a volume circuit for amplifying the reception signal.

[0012] Further, the present invention is characterized in that a plurality of earphones are provided, and a single microphone enables hands-free simultaneous communication even if only one person is the other party.

Further, referring to FIG. 1, the simultaneous telephone handset 1 of the present invention is a portable mobile communication terminal 3 which transmits and receives a voice signal through a plug 2 connected to an earphone jack 8 of the mobile communication terminal. It is characterized in that it is possible to carry out delivery.

A receiving signal of the portable mobile communication terminal 3 is amplified by a receiving amplifier circuit 9, a receiving voice is output from a plurality of earphones connected to the transmitter / receiver, and the transmitting voice is collected by the microphone 5 of the main body. It is characterized in that the level of the transmission signal can be adjusted by the sound transmission amplifier circuit 10 and the transmission voice signal is output to the portable mobile communication terminal via the plug 2.

Furthermore, the earphone of the transmitter / receiver can prevent the microphone from collecting the received voice output from the device, thereby preventing generation of acoustic echo and howling.

(Operation) The simultaneous telephone handset 1 of the present invention
The transmission / reception voice signal of the portable mobile communication terminal 3 is transmitted and received by the plug 2 connected to the earphone jack 8 of the portable mobile communication terminal, thereby enabling connection to all portable mobile communication powder having the earphone jack. Is increasing the character.

Further, a reception signal of the portable mobile communication terminal 3 is amplified by a reception amplification circuit 9, and a reception sound is output from a plurality of earphones 4 connected to the main body, and a transmission sound is collected by a microphone 5 of the handset. Sound allows multiple people to make a call at the same time.

Further, at the same time, the microphone does not collect the received voice from the speaker, thereby preventing the occurrence of acoustic echo and howling.

Further, since the circuit configuration is simple, the device can be constructed at low cost.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Description of Configuration) First, an embodiment of a handset according to the present invention will be described in detail with reference to FIG.

Hands-free simultaneous telephone handset 1
Has a plug 2 and is connected to an earphone jack section of the portable mobile communication terminal 3 to perform transmission and reception of voice signals for transmission and reception. Earphones 4-1 and 2. . n are prepared and connected to the simultaneous telephone handset 1 directly or via an earphone jack. . The received voice from the mobile communication terminal 3 received by the mobile communication terminal 3 is output to n. The reception volume can be adjusted by the reception volume knob 6. The microphone 5 functions to collect the user's transmission voice and convert it into an electric signal, and adjusts the level by operating the transmission volume knob 7.

Next, the configuration of the handset according to the present invention will be described in detail with reference to FIG.

The receiving amplifier circuit 9 is specifically composed of an OP-AMP
(Operational amplifier) to amplify the reception signal from the portable mobile communication terminal 3, and adjust the volume of the reception sound from the earphone 4 by operating the reception volume knob 6. The transmission amplification circuit 10 amplifies or attenuates the transmission signal collected and output by the microphone 5 and adjusts the transmission signal level to the portable mobile communication terminal 3. The level-adjusted transmission signal is transmitted to the portable mobile communication terminal 3 via the plug 2.
Is transmitted to

Next, the detailed structure of the simultaneous telephone handset 1 will be described with reference to FIG. The receiving amplifier circuit 8
For example, an OP-AMP is configured to amplify a reception signal from the mobile communication terminal 3, control the amplification of the reception amplification circuit 8 by the volume control circuit 10, and operate the reception volume knob 6 to receive a signal from the earphone 4. The sound volume can be adjusted. At this time, all the plurality of earphones 4 have the same volume. However, the reception amplifier circuit 8 and the volume control circuit 10 may be provided for each earphone, and the volume may be adjusted by the reception volume knob 6 for each earphone. .

Further, the transmission amplifier circuit 9 collects the voices of a plurality of callers by the microphone 5, amplifies or attenuates the output transmission signal, and adjusts the level of the transmission signal to the mobile communication terminal. Volume control circuit 1 by adjusting the transmission volume knob 7
Perform in step 1. Then, the level-adjusted transmission signal is transmitted to mobile communication terminal 3 via plug 2.

(Explanation of operation) Next, the simultaneous telephone handset 1
1 will be described with reference to FIGS. 1 and 2. FIG. Usually, an earphone jack attached to the mobile communication terminal 3 is provided with a handset having an earphone called an earphone microphone and a small microphone, for example, to transmit a transmission / reception talk signal. The transmission signal of the mobile communication terminal 3 when using the earphone microphone is switched from the transmission signal of the microphone of the main body to the transmission signal of the earphone microphone. Similarly, the reception signal is output to the earphone without being output to the speaker of the main body. The transmission / reception signal at this time is transmitted to the earphone microphone via the plug.
In this apparatus, the transmission / reception of the transmission / reception signal with the mobile communication terminal 3 is performed using the same method. Therefore, the shape and electrical characteristics of the plug 2 can be the same as those of a commonly used plug of an earphone microphone.

The voice signal of the transmission / reception is taken into the simultaneous communication handset 1 via the plug 2 and divided into a transmission signal and a reception signal. The reception signal is amplified or attenuated in the reception amplification circuit 8 by the control signal of the volume control circuit 10 and transmitted to the plurality of earphones 4. Here, the receiving amplifier circuit 8 is a negative feedback amplifier circuit composed of, for example, an OP-AMP, and changes the feedback resistance value by operating the receiving volume knob 6 or sets the input level of the amplifier circuit 8 to a three-terminal resistance. It is used to adjust the amplification factor. The user can wear the earphone 4 on his / her ear and operate the reception volume knob 6 to adjust the reception voice to an optimum volume and listen.
In addition, a receiving amplifier circuit 8 and a volume control circuit 1 are provided for each earphone.
By adjusting the reception volume knob 6 of each individual with 0, it is possible to adjust the volume optimally for each individual.

The transmitted voice of the user is collected by the microphone 5 and converted into a transmitted voice signal. Next, the transmission voice signal is amplified or attenuated by the control signal of the volume control circuit 11 in the transmission amplification circuit 9 and output to the mobile communication terminal 3 via the plug 2. The transmission voice signal here is transmitted to a transmission amplification circuit 9 by operating the volume knob 7 of the user.
For example, the amplification factor is adjusted by changing the feedback resistance value.

In the above embodiment, the simultaneous telephone handset 1 has been described as being of a placement type that is placed on a desk, but may be a portable simultaneous telephone handset. That is, a plurality of earphone jacks to which a plurality of earphones 4 can be connected, a volume control knob for the earphone 4, an omnidirectional microphone, a signal line for transmission / reception signals to the mobile communication terminal 3, and a power supply from the mobile communication terminal 3. With a plug for connection including a line,
It is possible to receive a power supply from the mobile communication terminal 3 and control the volume with a knob so that the mobile phone can be a portable simultaneous telephone handset. As a result, a portable telephone handset with good portability can be obtained more easily.

Further, when talking with a plurality of people, the microphone can be omnidirectionally received and hands-free, so that the head of the transmitted voice does not occur, and when the environmental sound is loud, It is also possible to provide an audio filter capable of limiting the frequency band in the output section of the microphone, so that only the voices of a plurality of persons can be transmitted, and clear transmission and reception can be performed with sound quality.

[Other Embodiments] Other embodiments of the present invention will be described. In the above embodiment, the simultaneous call in the case of using the mobile communication terminal has been described, but by replacing the plug, or by attaching a jack corresponding to the plug, even in a home fixed telephone, This simultaneous call handset can be used.

Further, by changing the diameter of the plug and connecting to a radio, a television, a compact disc player, or the like, a plurality of persons can listen to the same sound at the same time, and can also listen to music and information. It becomes possible.

[0033]

According to the present invention, by distributing the reception signal of the portable mobile communication terminal to a plurality of earphones, a plurality of persons can listen to the reception voice at the same time, and a call can be made to the microphone of the handset. , So that multiple people can talk at the same time using one portable mobile communication terminal.

Also, unlike the ordinary hands-free device, the structure of the present invention is such that the received voice is not output from the speaker but is output from the earphone, so that the acoustic coupling between the transmitted and received voices is very small and a complicated circuit configuration is required. In addition, since it is possible to suppress the occurrence of acoustic echo and howling, it has become possible to realize a simultaneous telephone handset without acoustic echo and howling at low cost.

Furthermore, since the voice signal of the transmission / reception of the portable mobile communication terminal is transmitted and received by the plug connected to the earphone jack of the portable mobile communication terminal, connection to most portable mobile communication terminals is possible. That is.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Simultaneous call transmitter / receiver 2 Plug 3 Portable mobile communication terminal 4 Earphone 5 Microphone 6 Reception volume knob 7 Transmission volume knob 8 Earphone jack of portable mobile communication terminal 9 Reception amplification circuit 10 Transmission amplification circuit

Claims (5)

[Claims] A plurality of earphones attached to an ear for outputting sound, a plug connected to an earphone jack of a portable mobile communication terminal and capable of extracting a transmission / reception voice signal, a microphone for collecting sound, An amplifier circuit for amplifying an audio signal collected by a microphone; a volume circuit for adjusting a volume level to the earphone; an amplifier circuit for a reception signal from the portable mobile communication terminal; and adjusting a volume level of the reception signal. A handset having a volume circuit. 2. The handset according to claim 1, wherein the handset has a plurality of amplifying circuits and a plurality of volumes in accordance with the plurality of earphones, and allows a plurality of persons to perform a simultaneous call using the microphone. . 3. The plug according to claim 1, wherein the plug has a power supply line, and the microphone is an omnidirectional type, and is a portable type like the portable mobile communication terminal. Handset as described. 4. The handset according to claim 1, wherein the amplifier comprises an operational amplifier, and the volume circuit changes a feedback amount of the operational amplifier. 5. A portable communication terminal system, wherein the handset according to claim 1 is connected to the portable mobile communication terminal.