JP2000349708A - A plurality of voice simultaneous communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a plurality of voice simultaneous communication system that can sent/receive 3 kinds or more of voice signals wirelessly within a specific space simultaneously at a low cost without leakage of the voice signals externally. SOLUTION: A wireless transmission medium uses an infrared ray signal Ir and adopts AM modulation/demodulation (AM modulation section 1d and AM demodulation section 2c) for a modulation/demodulation system. Since the transmission medium uses the infrared ray signal Ir, the voice signal is not leaked to the outside of a specific space and since the transmission medium adopts the AM modulation/demodulation system, the system can be built up at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of audio signals capable of simultaneously transmitting and receiving three or more kinds of audio signals having different languages, contents, voice qualities and the like in a specific and same space. The present invention relates to a voice simultaneous communication system.

[0002]

2. Description of the Related Art For example, in the case of an international conference, if audio signals of different languages are simultaneously transmitted wirelessly at different frequencies into a conference hall, each visitor borrows a receiver tuned to a frequency corresponding to a desired language. This makes it possible to listen to the interpreter's voice in the specific language previously desired when desired, which is convenient for the progress of the international conference.

[0003] When exhibiting a product, if different guides (contents) are simultaneously transmitted wirelessly to the exhibition hall at different frequencies, each visitor may rent a receiver that tunes to a frequency corresponding to the desired guide. When desired, the user can listen to a specific guide previously desired, which is convenient for each exhibition guide.

Therefore, a simultaneous multiple voice communication system capable of simultaneously wirelessly transmitting and receiving a plurality of types of audio signals having different languages, contents, and voice qualities has been proposed.

[0005] As a conventional system of this type, a system adopting a frequency multiplexing system in which a different frequency is assigned to each audio signal, modulated, and transmitted as one transmission radio wave to space is mainly used.

[0006]

However, the above-mentioned conventional system has the following problems.

That is, there is a case where it is desired to transmit and receive an audio signal only in one spatially partitioned specific venue due to circumstances such as holding the conference or exhibition confidentially or for a fee. In such a case, in the above-mentioned conventional system, since radio waves are used as a wireless transmission medium, an audio signal transmitted wirelessly in the venue propagates outside the venue and is intended for public disclosure such as confidential or paid information. There is a problem that information that is not leaked to the outside.

[0008] In view of the above, a system has been considered in which infrared rays are used as a wireless transmission medium so that information that is not intended to be disclosed to the general public is prevented from leaking from one spatially partitioned specific venue to the outside.

In this type of conventional transmission system, in order to maintain a certain transmission quality, a carrier signal is secondarily modulated with an FM-modulated voice signal, and an infrared signal based on the secondary modulation signal is transmitted as a transmission medium. And on the receiving side:
An FM signal is demodulated from the photoelectrically converted infrared signal to obtain an audio signal. However, components for FM modulation and demodulation that can transmit and receive in a plurality of different frequency bands, particularly components that perform FM modulation in different desired frequency bands, are difficult to obtain on the market and are expensive. . For example, C
Although there is a transmission system that performs FM modulation / demodulation in a specific frequency band for D (compact disc) and audio, there are two channels, that is, two types because it is a component for stereo (two channels) broadcasting. Can only transmit and receive audio signals simultaneously. Therefore, three or more channels cannot be transmitted and received simultaneously by dividing the frequency band, and it has not been possible to construct a system at a low cost by using the system as it is.

[0010] It is an object of the present invention to simultaneously transmit and receive three or more types of audio signals within a specific and same space,
Moreover, it is an object of the present invention to provide a multiple voice simultaneous communication system which can be realized at a low cost without leaking a voice signal to the outside.

[0011]

According to a first aspect of the present invention, there is provided a multiple voice simultaneous communication system, which converts a voice into an electric signal, amplifies the signal, modulates a carrier of a specific frequency based on the signal, and
Wireless transmission and reception of audio signals is performed between a transmitter that sends out to a space using a wireless transmission medium and a receiver that receives, tunes, demodulates, amplifies, and then converts the signals sent out from the transmitter into audio. An audio communication system comprising three or more transmitters having different carrier frequencies and three or more receivers each of which has a tuning frequency adjusted to the carrier frequency of the transmitter, and which is specified in the same space. In a multiple voice simultaneous communication system capable of wirelessly transmitting and receiving more than one kind of voice signal at the same time, the wireless transmission medium is an infrared ray and modulation / demodulation is AM modulation / demodulation.

From each transmitter, an infrared signal obtained by AM-modulating a carrier having a frequency unique to the transmitter with an audio signal is transmitted to the receiver. The receiver tunes at a frequency unique to the transmitter from the signal obtained by photoelectrically converting the infrared signal, and performs AM demodulation to obtain an audio signal of the specific transmitter. Since each transmitter transmits an infrared signal at a unique frequency different from each other, three or more types of audio signals can be transmitted and received in the same space. In addition, since the AM modulation / demodulation method is employed, inexpensive components can be used.

[0013]

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

FIG. 1 is a block diagram showing one embodiment of a multiple voice simultaneous communication system according to the present invention.

In FIG. 1, reference numerals 1 ₁ , 1 ₂ ,... 1 _{n denote} first to n-th transmitters 2 ₁ , 2,.
2 _2, ... _{2 n} is the first to n receiver comprising AM demodulation is used in the demodulation system.

Each of the transmitters 1 (1 ₁ , 1 ₂ ,... 1 _n ) includes a transmitter 1 a composed of a microphone or the like and an audio signal amplifier 1.
b, a carrier oscillating section 1c, an AM modulating section 1d, and a light emitting section (infrared transmitting section) 1e. Carrier oscillator 1
oscillation frequency (carrier frequency) f of c is different for each transmitter 1, wherein the transmitter 1 ₁ f1, the transmitter 1 ₂
Is f2, ... transmitter 1 _n is set to fn.

The transmitter 1a converts voice into an electric signal (voice signal) s1a, and the voice signal amplifier 1b transmits the voice signal to the transmitter 1a.
The carrier signal s1a is amplified, and the carrier oscillation section 1c generates a carrier (carrier) s1c of a predetermined frequency. The AM modulator 1d AM modulates (amplitude modulates) the carrier s1c with the amplified audio signal s1b from the audio signal amplifier 1b, and the light emitting unit 1e converts the output signal (modulated wave) s1d from the AM modulator 1d into infrared light. It is converted into a signal Ir1 and output (wireless transmission). In addition, Ir
2 to Irn are the _second to _n- th transmitters 12 1 to 1 _n (each light emitting unit 1
This is an infrared signal output from e).

Each receiver 2 (2 ₁ , 2 ₂ ,... 2 _n ) includes a light receiving section (infrared ray receiving section) 2a, a tuning section 2b, and an AM demodulating section 2.
c, an audio signal amplifier 2d and a receiver 2e including an earphone, a speaker, and the like. Here, the receiver is formed as a wireless headphone type. The tuning frequency f of the tuning portion 2b different from each receiver 2 where the receiver 2 ₁ f1, receiver 2 ₂ f2, ... receiver 2 _n is fn
Is set to

The light receiving section 2a receives (receives) the infrared signal Ir (Ir1, Ir2... Irn) output from the transmitter 1 and converts it into an electric signal s2a, and the tuning section 2b receives the electric signal from the light receiving section 2a. It selects and outputs only the electric signal (modulated wave) s2b of frequency f1 from s2a.

The AM demodulation unit 2c performs AM demodulation on the electric signal s2b from the tuning unit 2b to perform AM demodulation (sound signal) s.
2c, the audio signal amplifier 2d amplifies the audio signal s2c from the AM demodulator 2c, and the receiver 2e converts the amplified audio signal s2d from the audio signal amplifier 1b into audio and outputs the audio.

Next, the operation of the system of the present invention will be described with reference to FIGS.

[0022] In this case, the above-described system of the present invention is applied to the audio conferencing system in the international conference, the voice of the speaker, the first transmitter 1 ₁ Japanese, the second transmitter 1 ₂ English, the n-th French the transmitter 1 _n, is voice translated each input, the language interpreter audio 3 countries in a particular 1 hall partitioned spatially selective, the case was made to be listened.

When a Japanese voice is input to the transmitter 1a of the first transmitter ₁₁ , the transmitter 1a converts the input Japanese voice into an electric signal (voice signal) s1a. The audio signal s1a is amplified by the audio signal amplifying unit 1b, and then supplied to the AM modulation unit 1d. The AM modulator 1d includes:
The carrier s1c of the frequency f1 generated by the carrier oscillating unit 1c is converted into an amplified audio signal s from the audio signal amplifying unit 1b.
AM modulation is performed at 1b, and the resultant is given to the light emitting unit 1e. The light emitting section 1e converts the output signal s1d from the AM modulation section 1d into an infrared signal Ir.
Convert to 1 and output to the venue (wireless transmission).

[0024] The first receiver _{2 1} is a portable receiver that can listen to the Japanese, the first receiver _{2 1} of the light-receiving portion 2a
Represents the infrared signal Ir (Ir1, Ir1) output from the transmitter 1.
Ir2... Irn) is received (received) and converted into an electric signal s2a. This electric signal s2a is given to the tuning unit 2b,
After only the electric signal s2b of the frequency f1 is selected from the electric signals s2a, the electric signal s2b is supplied to the AM demodulation unit 2c. The AM demodulation unit 2c performs AM demodulation on the electric signal s2b from the tuning unit 2b and outputs an AM signal (audio signal) s2c. The audio signal s2c is amplified by the audio signal amplifier 2d,
e converts the amplified audio signal s2d from the audio signal amplifier 2b into audio (Japanese audio) and outputs it.

[0025] borrowed this by the first receiver _{2 1,}
Visitors who wish to speak Japanese can listen to the contents of the meeting in Japanese.

[0026] voice translated into English in the second transmitter 1 ₂ transmitter 1a is input, the second transmitter 1 ₂ operates in the same manner as in the first transmitter 1 _1, also, the also 2 receiver 2 ₂ operates in the same manner as in the case of the first receiver 2 _1, the second receiver 2 ₂ borrowed, English voice hope of visitors can listen to the conference content in English voice. In addition, s1a, s1b, s1 in FIG.
c (f2), s1d and Ir2 are electrical signals from the transmitter 1a to the second transmitter _{1 2} (audio signal), the amplified audio signal from the audio signal amplifier 1b, the carrier (carrier wave from the carrier oscillation unit 1c ), An output signal (modulated wave) from the AM modulation section 1d and an infrared signal output from the light emitting section 1e.

[0027] Similarly, when the voice translated into French third transmitter 1a of the transmitter 1 ₃ is inputted, the third receiver 2
Visitors who have borrowed ₃ and wish to speak French can listen to the contents of the meeting in French.

[0028] Each transmitter _{1 (1 1, 1 2,} ... 1 n) when at the same time from the infrared signal Ir (Ir1, Ir2 ... Irn) is transmitted, the receiver 2 (the light-receiving portion 2a) is All these infrared signals Ir will be received. However, each receiver 2 has a carrier frequency f (f
1, f2,... Fn) are provided with tuning units 2b which tune separately from each other. Among the electric signals (electric signals based on all the infrared signals Ir) s2a from the light receiving unit 2a, the electric signals of the specific frequency f Since only the modulated wave s2b is selected and demodulated by the AM demodulation unit 2c, it is possible to hear from the receiver 2e a voice (voice without interference) made only by the target voice signal.

In the above embodiment, the case where the system of the present invention is applied to a voice conference system has been described.
It goes without saying that the present invention is not limited to this.

[0030] For example, in the above embodiment has been described in the system for transmitting the one-way audio signals to the receiver 2 from the transmitter 1, the transmitter 1 (1 _{1, 1} 2, _... 1 _n) to the receiver 2
Alternatively, the function of the transmitter 1 may be provided in the receiver 2 so that voice transmission and reception can be performed in both directions.

Each receiver 2 (2 ₁ , 2 ₂ ,... 2 _n )
Are portable types so that they can be carried by individuals. However, as shown by broken lines in FIG.
The output of each receiver 2 may be connected to the input of the handset 3 as a part of the handset 3, and each audio signal may be output from the common handset 3 to, for example, the telephone line 4 or a speaker in the field. .

Furthermore, the light receiving section (infrared ray receiving section) 2a has been described as an example provided for each of the receivers 2 (2 ₁ , 2 ₂ ,... 2 _n ), but is shared by a plurality of receivers 2. It may be something.

[0033]

As described above, according to the present invention, since infrared rays are used as a wireless transmission medium, there is an effect that sound signals can be prevented from leaking out of a specific space.

Further, since AM modulation / demodulation is used as the modulation / demodulation method, there is also an effect that simultaneous wireless transmission / reception of three or more types of audio signals in the same specific space can be realized at low cost.

That is, when the FM modulation / demodulation is used as the modulation / demodulation method as described above, only components for stereo (2 channel) broadcasting are inexpensively available as components thereof. For a low-cost system configuration, only two types of audio signals could be transmitted and received simultaneously. However, when AM modulation / demodulation is used as the modulation / demodulation method as in the system of the present invention, inexpensive parts for AM radio can be used as the parts.

Also, as specified in AM radio broadcasting, it is specified at a low frequency of the medium wave band (a frequency capable of sufficiently coping with general-purpose light-emitting and light-receiving elements constituting a main structure of a light-emitting portion and a light-receiving portion) and placed in the same space. Wireless transmission and reception of three or more types of audio signals at the same time. Therefore, as described above, simultaneous wireless transmission and reception of three or more types of audio signals in a specific and same space can be realized at low cost.

According to the AM modulation / demodulation method, the FM modulation / modulation
Although the sound quality is more likely to be lower than in the case of the demodulation method, the required sound quality performance can be satisfied because the system of the present invention transmits and receives voice.

[0038]

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the system of the present invention.

FIGS. 2 (a), (b), (c), (d), (e),
(F), (g), (h), (i) is a signal waveform diagram of each part of the first transmitter and the first receiver in FIG.

FIGS. 3 (a), (b), (c), (d), (e)
FIG. 2 is a signal waveform diagram of each part of a second transmitter in FIG. 1.

[Explanation of symbols]

1 (1 ₁ , 1 ₂ ,... 1 _n ) transmitters (first to n-th transmitters) 1a transmitter 1b audio signal amplifier 1c carrier oscillator 1d AM modulator 1e light emitter (infrared transmitter) 2 ( 2 ₁ , 2 ₂ ,... 2 _n ) Receivers (first to n-th receivers) 2a Light receiving unit (infrared receiving unit) 2b Tuning unit 2c AM demodulation unit 2d Audio signal amplifier unit 2e Receiver Ir (Ir1, Ir2,...) Irn) Infrared signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/04 10/06 H04R 23/00 320

Claims (1)

[Claims] 1. A transmitter (1) which converts a sound into an electric signal, amplifies the signal, modulates a carrier of a specific frequency (f) based on the signal, and transmits the modulated signal to a space through a wireless transmission medium. An audio communication system for wirelessly transmitting and receiving an audio signal to and from a receiver (2) that receives, tunes, demodulates, amplifies, and converts the signal sent from a transmitter (1) to an audio signal. Three or more transmitters (1) having different frequencies (f) and tuning frequencies individually adjusted to the carrier frequencies (f) of the transmitters (1).
In a multiple voice simultaneous communication system including at least three receivers (2) and capable of wirelessly transmitting and receiving three or more types of voice signals simultaneously in a specific and same space, the wireless transmission medium is infrared, and modulation / demodulation is AM modulation / demodulation. A simultaneous multiple voice communication system characterized by demodulation.