JPH06224821A - Communication equipment - Google Patents

Abstract

PURPOSE:To provide a communication equipment which can surely and occasionally transmit the messages to the users as necessary. CONSTITUTION:A transmitter 1 consists of a 1st transmitter 10 which transmits a message to a specific user and a 2nd transmitter 20 which transmits the voices, etc., to all users. A 1st transmitter circuit 14 applies the AM modulation to the carrier signal of frequency fm by the voice signal supplied from a microphone 11 and outputs the modulated output signal. A call signal generator circuit 22 produces the signals (call signals of frequency f11-f1n) out of the audibel bands corresponding to the receivers of users so that the receiver 3 of the specific user is called. A mixer 23 superposes the call signal produced by the circuit 22 onto the voice signal produced by a CD player 21 and inputs these superposed signals to a 2nd transmitter circuit 24. The circuit 24 applies the AM modulation, for example, to the carrier signal of frequency fa by the output signal of the mixer 23 and then transmits the modulated carrier signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device for transmitting a voice or the like having the same content to a certain range of users and transmitting predetermined information only to a specific user.

[0002]

2. Description of the Related Art Background music (BGM) is conventionally played in an office in order to provide a comfortable work environment and improve work efficiency. This BGM is usually provided by, for example, installing a speaker on a wall or ceiling of an office, supplying an audio signal from a CD player or the like to the speaker through an amplifier, and flowing the BGM into the office. Is.

Alternatively, for example, music broadcasting is performed using weak radio waves, and the broadcast radio waves are received by the receivers owned by the respective users, and each user receives the B-wave through the headphones.
It may be done by listening to GM.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the case of providing the message to the user via the speaker, noise such as the voice of the person at work or the sound of the OA device may be mixed with BGM, which may hinder the work. Alternatively, there is a problem that the user has no choice to listen or not listen to the BGM, and the BGM can be heard even by a person who does not want to listen to the BGM.

On the other hand, as described above, BG is generated by using radio waves.
When M is provided, the user listens to BGM by using headphones because of the above problems. For this reason, even if an attempt is made to inform the user who is listening to BGM that a call is being made by using, for example, headphones, the user may miss the voice. That is, there is a problem in that it is difficult for such a user to hear a necessary voice other than BGM.

Further, the reduction of working hours is the most important issue in modern times, and it is necessary to shorten the working hours without lowering the productivity. Among these issues, how to improve the productivity of intellectual work is an important issue. The solution to this problem depends on how focused the work is. In order to improve such concentration of work, BGM
The use of is one of the effective means.

The present invention has been made in view of the above-mentioned demands and the problems of the prior art.
Despite being able to select whether or not to listen to M, it is possible to reliably and reliably transmit a message to the user as needed, and further improve the productivity of intellectual work by using BGM. It is an object of the present invention to provide a communication device that can be operated.

[0008]

In order to solve the above-mentioned problems of the prior art, the communication apparatus of the present invention has a transmitter and a plurality of receivers, and the transmitter has a common receiver. Signal transmitting means for transmitting a common reception signal to be received and further transmitting a calling signal of a different frequency uniquely assigned to each receiver, and an information signal to a specific receiver designated by the calling signal. And a plurality of receivers, each of which receives a common reception signal from the signal transmission unit, a calling signal, and an information signal from the information transmission unit, and demodulates the received signal.
Receiving means for obtaining a demodulated signal, signal detecting means for detecting a demodulated signal of the receiving means, which signal is assigned to itself among the calling signals, and assigning itself to the calling signal in the signal detecting means And a reception frequency control means for controlling the reception means so as to switch the reception signal based on the detection result from the signal of the signal transmission means to the signal of the information transmission means when the detected signal is detected. .

The information signal transmitted by the information transmitting means is a message signal to the receiver to which the unique frequency component is assigned.

Further, the calling signal is a signal outside the audible frequency band.

[0011]

In the communication device of the present invention, in addition to the voice provided to all users, a signal outside the audible band is assigned to each of the receivers that receive broadcast waves. Further, in addition to the frequency for broadcasting voice and the like provided to all users, a frequency for transmitting a message to a specific user is provided.

When calling a specific user, the transmitter side superimposes a calling signal corresponding to the receiver owned by the intended user, for example, a voice or the like which provides a signal outside the audible band to all users. To do. The receiver, which has detected the signal outside the audible band, transmits the received message to the user by switching the reception frequency by the reception frequency control means and receiving the frequency for transmitting the message for a certain time.

[0013]

Embodiments of the communication device of the present invention will be described below. FIG. 1 is a diagram showing a configuration of a transmitter 1 of a communication device of the present invention. The transmitter 1 includes a first transmitter 10 for transmitting a message to a specific user and a second transmitter 20 for transmitting a voice or the like provided to all users.

In FIG. 1, the microphone 11 inputs a message to a specific user into the first transmitter 10. The first transmission circuit 14 transmits the carrier wave signal of the frequency f _m to the microphone 1
For example, AM modulation is performed on the voice signal input from the signal No. 1 and the modulated wave output signal is transmitted from the first antenna 15. C
The D player (CDP) 21 is a BG provided to the user.
Generate M audio signals.

The call signal generation circuit 22 is for calling a receiver 3 _i (i = 1 to n) owned by a specific user, and is a signal outside the audible band corresponding to the receiver owned by each user ( Call signal: Generates frequencies fl _{1 to} fl _n ). The selection switch 221 is used to select any one of the call signals. Sending switch 22
2 is selected by the selection switch 221 and the oscillation circuit (O
(SC) 223 superimposes the call signal generated in 223 on the BGM. The oscillator circuit 223 generates a calling signal of the frequency selected by the selection switch 221, and inputs it to the mixer 23.

The mixer 23 is a calling signal generation circuit 2
The calling signal generated in 2 is superimposed on the audio signal generated in the CD player 21 and input to the second transmission circuit 24. The second transmission circuit 24, for example, AM-modulates the carrier signal of the frequency f _a with the output signal of the mixer 23, and sends it from the second antenna 25. The first transmitter 10
Also, the transmission output of the second transmitter 20 is weak within the range that can be used without permission, and in the present embodiment, the frequency f _m is 1400 KHz and the frequency f _a is 1500.
KHz. The receiver 3 _i is possessed by each user of the communication device of the present invention, and receives a signal from the transmitter 1.

FIG. 2 shows a receiver 3 of the communication device of the present invention.
It is a figure which shows the structure of _i (i = 1-n). The system of one communication device has n receivers 3 _i . It is owned by each user and is used for receiving BGM and messages. The tuning circuit 32 includes the receiving antenna 31.
The radio wave from the transmitter 1 captured by the
To enter.

The antenna coil 321 is, for example, a general type.
It is a bar antenna used for AM radio and is the secondary side.
The coil of is with variable capacitance diodes 322, 323
It constitutes an LC tuning circuit. This variable capacitance diode
The capacities of 322 and 323 are the calling signal detection circuit (fl _i
Detection) 35, the tuning circuit 32 is controlled by the output voltage of
Number f_mOr frequency f _aTune to one of the frequencies
It

The receiving circuit 33 amplifies the received signal input from the tuning circuit 32 and inputs it to the detection circuit 34. The receiving system of the receiving circuit 33 may be a super-heterodyne system or any other system, for example, an autodyne system. However, when the frequency conversion method is adopted, the output signal of the calling signal detection circuit 35 is input as shown by the dotted line in FIG. 2 for controlling the oscillation frequency of the local oscillation circuit.

The detection circuit 34 AM-detects the output signal of the reception circuit 33 and reproduces the audio signal sent from the transmission side. The call signal detection circuit (fl _i detection) 35 is provided with a frequency fl uniquely assigned to each receiver 3 _i.
The call signal of _i is detected and the reception frequency control signal is generated. The configuration of the call signal detection circuit 35 will be described later.

The low frequency amplifier (AF) 36 is a detector circuit 3
The audio signal output from the speaker 4 is amplified and output from the speaker 37. Here, other components such as headphones may be connected to the low frequency amplifier 36.

FIG. 3 is a diagram showing the configuration of the call signal detection circuit 35. In FIG. 3, a bandpass filter (BPF) 351 extracts the component of the frequency fl _i of the calling signal corresponding to the receiver 3 _i from the output signal of the detection circuit 34. The rectifier circuit 352 is a bandpass filter 3
The output signal of 51 is rectified into a positive DC signal.

The comparison circuit 353 compares the power supply voltage (V +) with the reference voltage (V _ref ) obtained by dividing the power supply voltage (V +) by the resistors R1 and R2, and based on this reference voltage, the rectifier circuit 3
When the value of the output voltage of 52 is high, the logical value 1 is output, and in other cases, the logical value 0 is output.

The control voltage generation circuit 354 is a comparison circuit 35.
3 has a logical value of 0, the variable capacitance diodes 322 and 323 of the tuning circuit 32 output _a voltage (V _a ) that tunes to the frequency f _a, and the output signal of the comparison circuit 353 has a logical value of 0 to a logical value. When it changes to 1, the variable capacitance diodes 322, 3 of the tuning circuit 32 for a predetermined time, for example, 20 seconds.
23 outputs a voltage (V _m ) which is tuned to the frequency f _m .

The operation of the transmitter 1 and the receiver 3 _i of the present invention will be described below with reference to the drawings. In addition, the first transmission circuit 14, the first antenna 15, the second transmission circuit 24, the second antenna 25, and the reception circuit 33 of the receiver 3 _i of the transmitter 1.
Since each part such as is equivalent to a commonly used part, the description of the operation is appropriately omitted.

FIG. 4 is a diagram showing the frequency relationship of radio waves used in the transmitter 1 and the receiver 3 _i . Transmitter 1
Audio broadcasting, for example, BGM broadcasting is always performed at the frequency f _a , and each receiver 3 _i normally receives the audio broadcasting at the frequency f _a . The frequency fs ₁ shown in the figure is the frequency f
shows the occupied bandwidth of the audio broadcast at _a.

Here, it is assumed that the operator (operator) operating the transmitter 1 needs to call a user who is using the receiver 3 _k (1 ≦ k ≦ n), for example. The operator operates the selection switch 221 to set the calling frequency fl _k corresponding to the receiver 3 _k used by the intended user in the oscillation circuit 223. Oscillation circuit 223 generates a call signal of a frequency fl _k on the basis of this setting.

The operator further operates the sending switch 22.
2 is operated to input a calling signal to the mixer 23.
This calling signal is sent by the mixer 23 to the CD player 21.
Is superimposed on the audio signal (BGM) output from the input terminal and input to the second transmission circuit 24. The second transmission circuit 24 modulates the carrier signal of the frequency f _m by the voice signal and the calling signal, and the respective receivers 3 _i via the second antenna 25.
Send to.

The frequency of the calling signal is as shown in FIG. 4. For example, the calling frequency fl ₁ = 50 kHz.
z, fl ₂ = 51 kHz, ..., fln = (49+
n) Hz. This signal is received at each receiver 3 _i, in order to call signal detecting circuit 35 of each receiver 3 _i is different from the frequency of the call signal to be detected, the receiver 3 _k only call frequency fl _k The signal can be detected.

The call signal detection circuit 35 of the receiver 3 _k outputs the voltage V _a to the normal tuning circuit 32 while receiving the frequency f _a . Here, the call signal detection circuit 35 of the receiver 3 _k includes the frequency f in the output signal of the detection circuit 34.
When the call signal of l _k is detected, the voltage V _{m is set} to 2 for the variable capacitance diodes 322 and 323 of the tuning circuit 32.
Output for 0 seconds. Due to this voltage, the tuning frequency of the tuning circuit 32 becomes the frequency f _m , and the receiver 3 _k receives the frequency f _m . Here, fs ₂ in the figure indicates the occupied band of the audio signal at the frequency f _m .

On the other hand, the operator, after the above series of operations,
By the microphone 11 and the first transmission circuit 14, the receiver 3
_{Send a} message at frequency f _{m to} users using _k . This message is received by the receiver 3 _k, the receiver 3 _k of the user can listen to this message.
After 20 seconds from the call signal transmission start frequency fl _k, the output voltage of the calling signal detection circuit 35 becomes V _a, 3 _k receiver again returns to the reception frequency f _a.

The transmitter 1 and the receiver 3 _i of this embodiment are
Although it is configured to transmit a voice signal by AM modulation,
The audio signal may be transmitted by another method, for example, the FM modulation method. Further, it may be configured to perform stereo broadcasting instead of monaural broadcasting.

Each part of the transmitter 1 and the receiver 3 _i can be replaced with a circuit having an equivalent function. Further, the frequencies used by the transmitter 1 and the receiver 3 _i are not limited to those described above, and other frequencies such as the FM broadcast frequency band may be used. Also, transmitter 1
The information transmitted between the receiver 3 _i and the receiver 3 _i is not limited to voice information, and may be various data, for example.

Further, the transmitter 1 side is also provided with a receiving means, and the receiver 3 _i side is also provided with a transmitting means. When the receiver 3 _i detects a calling signal, it responds to the transmitter 1. May be returned, and various controls may be performed based on this response. Further, the receiver 3 _i may be provided with means for returning the reception frequency from the frequency f _m to the frequency f _a according to the judgment of the user.

Further, the receiver 3 _i may be configured to be able to receive frequencies other than the frequencies f _m and f _a . The sound source is not limited to the CD player, but may be, for example, a radio or the like. In addition to the embodiments described above, the communication device of the present invention is
For example, it is possible to adopt various configurations as in the above-described modified example. The embodiments described above are merely examples.

[0036]

As described above, according to the present invention, although the user can select whether or not to listen to the BGM, a message to the user can be sent as needed at any time.
It is possible to provide a communication device capable of surely transmitting and further improving the productivity of intellectual work by using BGM.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a transmitter of a communication device of the present invention.

FIG. 2 is a diagram showing a configuration of a receiver of the communication device of the present invention.

FIG. 3 is a diagram showing a configuration of a calling signal detection circuit.

FIG. 4 is a diagram showing a frequency relationship of radio waves used in a transmitter and a receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transmitter 10 ... 1st transmitter 11 ... Microphone 14 ... 1st transmission circuit 15 ... 1st antenna 20 ... 2nd transmitter 21 ... CD player 22 ... Call signal generation circuit 221 ... Selection switch 222 ... Sending switch 223 ... Oscillation circuit 23 ... Mixer 24 ... Second transmission circuit 25 ... Second Antenna 3 ... Receiver 31 ... Receiving antenna 32 ... Tuning circuit 321 ... Antenna coil 322, 323 ... Variable capacitance diode 33 ... Receiving circuit 34 ... Detection circuit 35. ..Call signal detection circuit 351 ... Band pass filter 352 ... Rectifier circuit 353 ... Comparison circuit 354 ... Control voltage generation circuit 36 ... Low frequency amplifier 37 ... Speaker

Claims (3)

[Claims] 1. A transmitter and a plurality of receivers, wherein the transmitter transmits a common reception signal commonly received by each receiver, and further, calls of different frequencies uniquely assigned to each receiver. A signal sending unit for sending a signal, and an information sending unit for sending an information signal to a specific receiver designated by the calling signal, wherein each of the plurality of receivers is common to the signal sending unit. A receiving unit for receiving and demodulating a received signal, a calling signal, and an information signal from the information sending unit to obtain a demodulated signal; and a demodulated signal of the receiving unit, a signal assigned to itself among the calling signals And a signal detection unit that detects the signal assigned to itself in the signal detection unit by the signal detection unit based on the detection result. Communication device a signal received from the signal of the signal transmitting means and a receiving frequency control means for controlling said receiving means to switch to signal the information transmitting unit Te. 2. The information signal transmitted by the information transmitting means is
The communication device according to claim 1, wherein the communication signal is a message signal to the receiver to which the unique frequency component is assigned. 3. The communication device according to claim 1, wherein the calling signal is a signal outside the audio frequency band.