JP7090801B2 - Transmitter, receiver, and wireless microphone system - Google Patents

Description

The present invention relates to a transmitter, a receiver, and a wireless microphone system.

The wireless microphone system described in Patent Document 1 includes a transmitting device and a receiving device. The transmitting device transmits a predetermined tone signal and an audio signal. When the receiving device receives a predetermined tone signal, the receiving device outputs an audio signal to an external device (for example, a speaker).

Japanese Unexamined Patent Publication No. 4-356826

By the way, in order to improve the selection accuracy of receiving a specific audio signal, an identification signal (identification signal indicating that it is a specific audio signal, for example, an ID signal) may be superimposed on the transmission signal. In this case, since the transmission signal includes the identification signal and the audio signal, there arises a problem that the audio signal cannot be properly extracted from the transmission signal.

An object of the present invention is to provide a transmitting device, a receiving device, and a wireless microphone system capable of appropriately extracting an audio signal.

(1) A transmission device according to one aspect of the present invention includes a voice acquisition unit that acquires a voice signal, a radio signal formation unit that forms a transmission signal including the voice signal, and a transmission unit that transmits the transmission signal. The transmission signal further includes a first tone signal, an identification signal superimposed on the first tone signal, and a second tone signal following the first tone signal, and the voice signal is the second tone. Overlaid on the signal.

According to this configuration, the audio signal is superposed on a second tone signal different from the first tone signal on which the identification signal is superposed. Therefore, it is possible to accurately inform the receiving device of the transmission timing of the audio signal. As described above, according to this transmission signal, the audio signal can be appropriately taken out.

(2) The receiving device according to one aspect of the present invention includes a first tone signal, an identification signal superimposed on the first tone signal, a second tone signal following the first tone signal, and the second tone signal. A receiving device that receives a transmission signal including an audio signal superimposed on the above, and the received signal includes an audio signal based on a receiving unit that receives the transmission signal and a reception signal received by the receiving unit. A determination unit for determining whether or not to use the determination unit and an extraction unit for extracting an audio signal from the received signal based on the determination result of the determination unit are provided, and the determination unit detects the first tone signal from the received signal. A first detection unit, a second detection unit that detects the second tone signal from the received signal, and a third detection unit that detects the identification signal from the received signal are provided, and the determination unit is the first. The second is based on the detection unit detecting the first tone signal, the third detection unit detecting the identification signal, and the second detection unit detecting the second tone signal. After the tone signal is detected, a signal for extracting an audio signal from the received signal is output to the extraction unit.

According to this configuration, when the determination unit detects the first tone signal, the identification signal, and the second tone signal, the determination unit determines that the signal including these includes an audio signal. Then, the extraction unit extracts the audio signal from the received signal after the detection of the second tone signal. As a result, it is possible to suppress that the first part of the audio signal is not extracted, and it is possible to appropriately extract the audio signal.

(3) Preferably, in the receiving device, the determination unit includes an intensity determination unit that determines whether or not the intensity of the received signal is larger than the first threshold value, and whether the noise intensity is smaller than the second threshold value. Further provided with a noise determination unit for determining whether or not, the determination unit determines that the intensity of the received signal is larger than the first threshold value, and the noise intensity is smaller than the second threshold value. The noise determination unit determines, the first detection unit detects the first tone signal, the third detection unit detects the identification signal, and the second detection unit detects the first tone signal. Based on the detection of the two-tone signal, after the detection of the second tone signal, a signal for extracting an audio signal from the received signal is output to the extraction unit.

According to this configuration, the determination unit outputs a signal for extracting an audio signal from the received signal to the extraction unit when the five requirements are met. As a result, the quality of the output audio signal can be improved as compared with the case where the presence or absence of the audio signal is determined based on the requirement of less than five.

(4) Preferably, in the receiving device, the taking-out unit includes a switching unit and a filter unit, and the switching unit outputs the received signal to the filter unit based on the determination result of the determination unit. The output state is switched between the output state and the non-output state in which the received signal is not output to the filter unit, and the filter unit outputs the audio signal by removing the second tone signal from the received signal. According to this configuration, an audio signal can be output.

(5) The wireless microphone system according to one aspect of the present invention includes the transmitting device and the receiving device.
According to this configuration, the audio signal can be appropriately taken out.

According to the transmitter, receiver, and wireless microphone system, the audio signal can be properly extracted.

Schematic diagram of a wireless microphone system. Block diagram of the transmitter. Schematic diagram of the transmission signal. Block diagram of the receiver. A timing chart showing the timing of each flag.

The wireless microphone system 1 will be described with reference to FIGS. 1 to 5.
The wireless microphone system 1 (hereinafter, simply referred to as “WL system 1”) includes a transmitting device 3, a receiving device 4, and a speaker 5. The transmission device 3 wirelessly transmits the transmission signal ST including the audio signal SD. The receiving device 4 receives the transmission signal ST transmitted from the transmitting device 3. The speaker 5 is connected to the receiving device 4. The speaker 5 magnifies the audio signal SD output from the receiving device 4.

The transmission device 3 will be described with reference to FIG.
The transmission device 3 includes a voice acquisition unit 10 (microphone) for acquiring the voice signal SD, a radio signal forming unit 11, and a transmission unit 12 for transmitting the transmission signal ST. The voice acquisition unit 10 outputs voice as a voice signal SD. The voice acquisition unit 10 is connected to the radio signal forming unit 11. The transmission unit 12 includes a transmission antenna. The transmission unit 12 wirelessly transmits the transmission signal ST. For example, the transmission unit 12 converts the transmission signal ST into radio waves and transmits the radio waves.

The radio signal forming unit 11 forms a transmission signal ST including an audio signal SD. The radio signal forming unit 11 includes an amplifier unit 20, an identification signal output unit 21, a first tone forming unit 22, a second tone forming unit 23, a superimposing unit 24, a modulation circuit 25, and a high frequency transmission circuit 26. To prepare for. Further, the radio signal forming unit 11 includes a first switch 27 and a second switch 28.

The amplifier unit 20 amplifies the audio signal SD. The amplifier unit 20 may have one stage or multiple stages.
The identification signal output unit 21 outputs the identification signal SC. The identification signal SC is a signal indicating that it is a specific audio signal, and is an ID signal corresponding to an ID code individually set for each transmission device 3. The ID code is composed of a plurality of codes. The identification signal output unit 21 may hold a preset identification signal SC or may form an identification signal SC. The identification signal SC is a signal for causing the receiving device 4 in the WL system 1 to authenticate that the transmission signal ST is transmitted from the transmitting device 3 in the WL system 1. The transmitting device 3 and the receiving device 4 in the WL system 1 hold a common identification signal SC.

The first switch 27 switches between a first connection mode for connecting the output unit of the amplifier unit 20 and the superimposing unit 24 and a second connection mode for connecting the identification signal output unit 21 and the superimposing unit 24. By the operation of the first switch 27, one of the audio signal SD and the identification signal SC is output to the superimposing unit 24.

The first tone forming unit 22 forms a first tone signal SA having a predetermined frequency. The second tone forming unit 23 forms a second tone signal SB different from the first tone signal SA. The second tone signal SB may be discriminated from the first tone signal SA. For example, the frequency of the second tone signal SB is different from the frequency of the first tone signal SA. The frequency of the first tone signal SA is preferably higher than the audible sound band so that the tone signal does not become jarring. Further, the frequency of the second tone signal SB is preferably a frequency higher than the audible sound band.

The second switch 28 is between a third connection mode for connecting the output unit of the first tone forming unit 22 and the superimposing unit 24 and a fourth connection mode for connecting the second tone forming unit 23 and the superimposing unit 24. To switch. By the operation of the second switch 28, one of the first tone signal SA and the second tone signal SB is output to the superimposition unit 24.

The first switch 27 and the second switch 28 are interlocked with each other. There are two switch states, the first switch state and the second switch state, which are configured by the operation of the first switch 27 and the operation of the second switch 28. The first switch state is a state in which the identification signal is switched to be transmitted. In the first switch state, the first switch 27 is set to the above-mentioned second connection mode, and the second switch 28 is set to the above-mentioned third connection mode. The second switch state is a state in which the audio signal SD is switched to be transmitted. In the second switch state, the first switch 27 is set to the above-mentioned first connection mode, and the second switch 28 is set to the above-mentioned fourth connection mode.

The superimposing unit 24 superimposes either one of the first tone signal SA and the second tone signal SB and one of the audio signal SD and the identification signal SC. Specifically, in the first switch state, the superimposing unit 24 superimposes the identification signal SC and the first tone signal SA. In the second switch state, the superimposing unit 24 superimposes the audio signal SD and the second tone signal SB.

The modulation circuit 25 modulates the signal output from the superimposition unit 24. The high frequency transmission circuit 26 converts the modulated signal into a high frequency frequency, and outputs the signal converted into the high frequency frequency to the transmission unit 12 as a transmission signal ST.

As described above, the transmission device 3 forms the transmission signal ST. As described above, the transmission signal ST includes the first tone signal SA, the identification signal SC superimposed on the first tone signal SA, the second tone signal SB following the first tone signal SA, and the second tone signal SB. Includes an audio signal SD superimposed on.

An example of the transmission signal ST will be described with reference to FIG.
A predetermined number of identification signal SCs are repeatedly superimposed on the first tone signal SA. The identification signal SC may be repeatedly superimposed on the first tone signal SA at predetermined intervals. The second tone signal SB follows the first tone signal SA. The audio signal SD is superimposed on the second tone signal SB. The first tone signal SA is a signal informing the receiving device 4 that the identification signal SC is being output. The second tone signal SB is a signal informing the receiving device 4 that the audio signal SD is being output.

The receiving device 4 will be described with reference to FIG.
The receiving device 4 includes a receiving unit 30, a determination unit 31, and an extraction unit 32. Preferably, the receiving device 4 further includes a high frequency receiving circuit 33 and a demodulation circuit 34.

The receiving unit 30 receives the transmission signal ST. The receiving unit 30 outputs the received transmission signal ST as a reception signal to the subsequent high-frequency reception circuit 33. The high frequency receiving circuit 33 receives a received signal from the receiving unit 30. The high frequency receiving circuit 33 converts the high frequency received signal into an intermediate frequency signal.

The demodulation circuit 34 receives the received signal converted to the intermediate frequency from the high frequency receiving circuit 33. The demodulation circuit 34 demodulates an intermediate frequency signal. The extraction unit 32 receives the demodulated received signal.

The extraction unit 32 extracts the audio signal SD from the received signal based on the determination result of the determination unit 31. When receiving the signal extraction command described later from the determination unit 31, the extraction unit 32 extracts the audio signal SD from the received signal and outputs the audio signal SD to the external device (speaker 5 in this embodiment). The take-out unit 32 does not output the audio signal SD from the received signal to the external device when it does not receive the signal take-out command described later from the determination unit 31.

For example, the take-out unit 32 includes a switching unit 35 and a filter unit 36.
The switching unit 35 switches between an output state in which the received signal is output to the filter unit 36 and a non-output state in which the received signal is not output to the filter unit 36, based on the determination result of the determination unit 31. In one example, the switching unit 35 is configured by the mute circuit 35C. The mute circuit 35C includes a signal line 35c connecting the circuit input unit 35a and the circuit output unit 35b, a ground line 35d connected to the ground, and a switch 35e connecting the signal line 35c and the ground line 35d. The signal line 35c transmits the received signal to the filter unit 36. When the signal line 35c and the ground line 35d are connected by the switch 35e, the received signal falls to the ground, so that the received signal is not output from the mute circuit 35C (“non-output state”). When the signal line 35c and the ground line 35d are not connected by the operation of the switch 35e, the received signal is transmitted through the signal line 35c and output to the circuit output unit 35b of the mute circuit 35C (“output state”). The filter unit 36 removes the second tone signal SB from the received signal and outputs the audio signal SD.

The determination unit 31 determines whether or not the reception signal includes the audio signal SD based on the reception signal received by the reception unit 30. Specifically, the determination unit 31 includes a calculation unit 40, a first detection unit 41, a second detection unit 42, and a third detection unit 43.

The calculation unit 40 outputs the determination result to the extraction unit 32 based on the signal input to the calculation unit 40. In the present embodiment, the arithmetic unit 40 fetches a command (hereinafter, “signal fetch command”) (for example, an on signal) for fetching the audio signal SD from the received signal when all five flags described later are on. Output to unit 32. Further, the arithmetic unit 40 does not output the signal extraction command to the extraction unit 32 when at least one of the five flags described later is off.

The first detection unit 41 detects the first tone signal SA from the received signal. When the first detection unit 41 detects the first tone signal SA, the first detection unit 41 outputs an on signal to the calculation unit 40. The second detection unit 42 detects the second tone signal SB from the received signal. When the second detection unit 42 detects the second tone signal SB, the second detection unit 42 outputs an on signal to the calculation unit 40. The third detection unit 43 detects the identification signal SC from the received signal. When the third detection unit 43 detects the identification signal SC, the third detection unit 43 outputs an on signal to the calculation unit 40.

Preferably, the determination unit 31 includes an intensity determination unit 44 and a noise determination unit 45 in addition to the first detection unit 41 to the third detection unit 43. The intensity determination unit 44 determines whether or not the intensity of the received signal is greater than the first threshold value. When the strength determination unit 44 determines that the strength of the received signal is larger than the first threshold value, the strength determination unit 44 outputs a signal indicating that the reception strength is sufficient (hereinafter, “receivable strength signal”) to the calculation unit 40. The noise determination unit 45 determines whether or not the noise intensity is smaller than the second threshold value. When the noise determination unit 45 determines that the noise intensity is smaller than the second threshold value, the noise determination unit 45 outputs a signal indicating that the noise is small (“allowable noise signal”) to the calculation unit 40.

As described above, the arithmetic unit 40 outputs a signal extraction command to the extraction unit 32 when all of the five flags described later are on. Specifically, the calculation unit 40 determines that (a) the intensity determination unit 44 determines that the intensity of the received signal is larger than the first threshold value, and (b) the noise determination unit 45 determines that the noise intensity is the second threshold value. (C) The first detection unit 41 detects the first tone signal SA, (d) the third detection unit 43 detects the identification signal SC, and (e) the first. 2 Based on the fact that the detection unit 42 detects the second tone signal SB, the signal extraction command is output to the extraction unit 32.

The operation of the receiving device 4 will be described with reference to FIG.
The transition of each flag in the calculation unit 40 when the transmission device 3 outputs the transmission signal ST will be described. The arithmetic unit 40 has a noise flag, an intensity flag, a first tone flag, a second tone flag, and an identification flag.

The noise flag is a signal based on the signal received from the noise determination unit 45. The noise flag is turned on based on the allowable noise signal of the noise determination unit 45. The noise flag is kept on for the state in which the calculation unit 40 is receiving the allowable noise signal, and is kept off when the calculation unit 40 is not receiving the allowable noise signal.

The intensity flag is a signal based on the signal received from the intensity determination unit 44. The intensity flag is turned on based on the receivable intensity signal of the intensity determination unit 44. The intensity flag remains on for the duration of the arithmetic unit 40 receiving the receivable intensity signal and remains off when the arithmetic unit 40 does not receive the receivable intensity signal.

The first tone flag is a signal based on the signal received from the first detection unit 41. The first tone flag is turned on based on the calculation unit 40 receiving an on signal from the first detection unit 41, and remains on even after the calculation unit 40 no longer receives the on signal from the first detection unit 41. Continue to do.

The second tone flag is a signal based on the signal received from the second detection unit 42 by the calculation unit 40. The second tone flag is turned on based on the calculation unit 40 receiving an on signal from the second detection unit 42. The second tone flag is kept on for the state in which the calculation unit 40 is receiving the on signal, and is kept off when the calculation unit 40 is not receiving the on signal.

The identification flag is a signal based on the signal received from the third detection unit 43. The identification flag is turned on based on the calculation unit 40 receiving an on signal from the third detection unit 43, and continues to be on even after the calculation unit 40 no longer receives the on signal from the third detection unit 43. ..

The operation of the arithmetic unit 40 will be described below.
When the transmission signal ST is transmitted from the transmission device 3, at time t1, the noise determination unit 45 determines the noise intensity based on the sufficiently high intensity of the received signal, and the noise intensity is higher than the second threshold value. Outputs an allowable noise signal based on its small size. When the noise determination unit 45 outputs an allowable noise signal, the noise flag is turned “on”.

After the time t1 (the period between the time t1 and the time t2), the first detection unit 41 detects the first tone signal SA. Depending on the configuration of the detection means of the first detection unit 41, the first tone signal SA may be detected at substantially the same time as the determination time (time t1) of the noise determination unit 45. The first detection unit 41 outputs an on signal during the period during which the first tone signal SA is being detected. At this time, the first tone flag becomes "on" and then continues to maintain the "on" state.

The intensity determination unit 44 constantly determines whether or not the intensity of the received signal is greater than the first threshold value. In this example, at the time t1 when the transmission signal ST is transmitted, the intensity determination unit 44 determines that the intensity of the received signal is larger than the first threshold value, and outputs an on signal. At this time, the strength flag is turned "on".

Since the signal demodulated by the demodulation circuit 34 includes the first tone signal SA and the identification signal SC, the third detection unit 43 detects the identification signal SC at time t2 after a while at time t1. To detect. When the third detection unit 43 detects the identification signal SC, the third detection unit 43 outputs an on signal. At this time, the identification flag is turned "on" and then continues to remain "on".

After that, at time t3, the second detection unit 42 receives the second tone signal SB. The second detection unit 42 outputs an on signal during the period during which the second tone signal SB is being detected. At this time, the second tone flag is turned "on".

At this point, the noise flag is on, the intensity flag is on, the first tone flag is on, the second tone flag is on, and the identification flag is on. At this time, the switching unit 35 is switched to the “output state”, and the received signal is output from the receiving device 4 to the external device (for example, the speaker 5) through the filter unit 36. When the noise flag is on, the intensity flag, the first tone flag, the second tone flag, and at least one of the identification flags are off, the switching unit 35 switches to the “non-output state”. In this case, the received signal from the receiving device 4 is not output to the external device. For example, at time t4, when the second tone flag is turned off by the second detection unit 42 not detecting the second tone signal SB, the switching unit 35 switches to the “non-output state”.

The operation of this embodiment will be described.
A reference example compared with the present embodiment will be described. In the transmission signal of the reference example, the identification signal SC and the audio signal SD are superimposed on one type of tone signal. In order to increase the accuracy of detecting the identification signal SC, the identification signal SC is repeatedly superimposed on the tone signal. After receiving the transmission signal, the receiving device switches the switching of the switching unit 35 to the "output state" when the identification signal SC is detected. However, when the receiving device detects the identification signal SC in the middle of the plurality of identification signal SCs on the time axis and the switching unit 35 switches to the "output state" at this point, the identification signal SC and the audio signal SD A tone signal including is output to an external device. Then, the external device receives the tone signal including the identification signal SC and the audio signal SD. Although the tone signal is removed by the filter, the identification signal SC and the audio signal SD remain in the signal received by the external device. Therefore, when the external device is the speaker 5, an unpleasant sound corresponding to the identification signal SC is reproduced. Become so. As a countermeasure, it is conceivable that the switching timing of the switching unit 35 is set after a predetermined period has elapsed from the time when the identification signal SC is detected. However, if the timing at which the identification signal SC is detected is late, the switching timing of the switching unit 35 is delayed, so that the first part of the audio signal SD out of the audio signal SD following the identification signal SC on the time axis is taken out. There is a risk that it will not be done. That is, in the case of the reference example, the receiving device cannot detect the boundary between the identification signal SC and the audio signal SD on the time axis, so that the signal output from the receiving device is not appropriate.

On the other hand, in the present embodiment, the identification signal SC is superimposed on the first tone signal SA, and the audio signal SD is superimposed on the second tone signal SB following the first tone signal SA. As a result, the boundary between the identification signal SC and the audio signal SD on the time axis can be detected as the switching point between the first tone signal SA and the second tone signal SB, so that the audio signal SD is appropriately output. become.

The effect of this embodiment will be described.
(1) The transmission signal ST is superimposed on the first tone signal SA, the identification signal SC superimposed on the first tone signal SA, the second tone signal SB following the first tone signal SA, and the second tone signal SB. The audio signal SD is included.

According to this configuration, the audio signal SD is superimposed on the second tone signal SB different from the first tone signal SA on which the identification signal SC is superimposed. Therefore, it is possible to accurately inform the receiving device 4 of the transmission timing of the audio signal SD. As described above, according to this audio signal SD, the audio signal SD can be appropriately taken out.

(2) The receiving device 4 superimposes the first tone signal SA, the identification signal SC superimposed on the first tone signal SA, the second tone signal SB following the first tone signal SA, and the second tone signal SB. Receives the transmission signal ST including the audio signal SD. The receiving device 4 has a determination unit 31 that determines whether or not the received signal includes the audio signal SD based on the received signal, and an extraction unit 32 that extracts the audio signal SD from the received signal based on the determination result of the determination unit 31. And prepare. The determination unit 31 detects the first detection unit 41 that detects the first tone signal SA from the received signal, the second detection unit 42 that detects the second tone signal SB from the received signal, and the identification signal SC from the received signal. A third detection unit 43 is provided. In the determination unit 31, the first detection unit 41 detects the first tone signal SA, the third detection unit 43 detects the identification signal SC, and the second detection unit 42 detects the second tone signal SB. Based on this, after the detection of the second tone signal SB, a signal for extracting the audio signal SD from the received signal is output to the extraction unit 32.

According to this configuration, when the determination unit 31 detects the first tone signal SA, the identification signal SC, and the second tone signal SB, the determination unit 31 determines that the signal including these includes the audio signal SD. Then, the extraction unit 32 extracts the audio signal SD from the received signal after the detection of the second tone signal SB. As a result, it is possible to prevent the first part of the audio signal SD from being extracted, and to appropriately extract the audio signal SD.

(3) Preferably, the determination unit 31 further determines whether or not the intensity of the received signal is larger than the first threshold value, and whether or not the noise intensity is smaller than the second threshold value. A noise determination unit 45 for determination is further provided. In the determination unit 31, the intensity determination unit 44 determines that the intensity of the received signal is larger than the first threshold value, the noise determination unit 45 determines that the noise intensity is smaller than the second threshold value, and the first detection unit 41. 2nd tone based on the fact that the first tone signal SA is detected, the third detection unit 43 detects the identification signal SC, and the second detection unit 42 detects the second tone signal SB. After the detection of the signal SB, the signal for extracting the audio signal SD from the received signal is output to the extraction unit 32.

According to this configuration, the determination unit 31 outputs a signal (signal extraction command) for extracting the audio signal SD from the received signal to the extraction unit 32 when the five requirements are met. As a result, the quality of the output audio signal SD can be improved as compared with the case where the presence or absence of the audio signal SD is determined based on the requirement of less than five. Here, the high quality of the audio signal SD means that the intensity is sufficiently high, the noise is small, and the signal is not an interfering signal.

(4) The take-out unit 32 includes a switching unit 35 and a filter unit 36. The switching unit 35 switches between an output state in which the received signal is output to the filter unit 36 and a non-output state in which the received signal is not output to the filter unit 36, based on the determination result of the determination unit 31, and the filter unit 36 switches between the output state and the non-output state in which the received signal is not output to the filter unit 36. , The audio signal SD is output by removing the second tone signal SB from the received signal. According to this configuration, the audio signal SD can be output.

(5) The WL system 1 includes the transmission device 3 and the reception device 4.
According to this configuration, the audio signal SD can be appropriately taken out. Therefore, it is suppressed that the first sound of the audio signal SD is not reproduced.

<Other embodiments>
The description of the embodiment is an example of the transmitting device 3, the receiving device 4, and the WL system 1. The transmitting device 3, the receiving device 4, and the WL system 1 may take a form in which the following modifications and at least two variants that do not contradict each other are combined. In the following modification, the parts common to the embodiment are designated by the same reference numerals as those in the embodiment, and the description thereof will be omitted.

The second tone signal SB may be discriminated from the first tone signal SA. In the embodiment, the frequencies of both tones are different. On the other hand, it may be configured as follows. The amplitude of the second tone signal SB may be larger than the amplitude of the first tone signal SA, and the amplitude of the second tone signal SB may be smaller than the amplitude of the first tone signal SA. In this case, in this case, the second tone signal SB may be the same as the tone frequency of the first tone signal SA, or may be a different tone frequency. By detecting the amplitude level, it is possible to determine the time point at which the first tone signal SA is switched to the second tone signal SB.

The audio signal SD may be superimposed from a time point delayed by a predetermined time from the time point of the boundary between the first tone signal SA and the second tone signal SB. As a result, it is possible to suppress an error that the first part of the audio signal SD is not taken out.

-The configuration of the receiving device 4 can also be applied to a receiving device having a diversity function. For example, in a receiving device having a plurality of antennas and a common circuit and switching antennas depending on a receiving state, the configuration of the receiving device 4 of the present embodiment can be applied to the common circuit of the receiving device. Further, in a receiving device having a plurality of receiving circuits (including an antenna) and switching the receiving circuit depending on the receiving state, the configuration of the receiving device 4 of the present embodiment can be applied to the receiving circuit of the receiving device.

SA ... 1st tone signal, SB ... 2nd tone signal, SC ... identification signal, SD ... voice signal, ST ... transmission signal, t1 ... time, t2 ... time, t3 ... time, t4 ... time, 1 ... wireless microphone system (WL system), 3 ... Transmitter, 4 ... Receiver, 5 ... Speaker, 10 ... Audio acquisition unit, 11 ... Radio signal forming unit, 12 ... Transmitter, 20 ... Amplifier, 21 ... Identification signal output unit, 22 ... 1st tone forming unit, 23 ... 2nd tone forming unit, 24 ... superimposing unit, 25 ... modulation circuit, 26 ... high frequency transmission circuit, 27 ... 1st switch, 28 ... 2nd switch, 30 ... receiving unit, 31 ... Judgment unit, 32 ... Extraction unit, 33 ... High frequency reception circuit, 34 ... Demodulation circuit, 35 ... Switching unit, 35a ... Circuit input unit, 35b ... Circuit output unit, 35C ... Mute circuit, 35c ... Signal line, 35d ... Ground line , 35e ... switch, 36 ... filter unit, 40 ... arithmetic unit, 41 ... first detection unit, 42 ... second detection unit, 43 ... third detection unit, 44 ... intensity determination unit, 45 ... noise determination unit.

Claims (5)

A voice acquisition unit for acquiring a voice signal, a radio signal forming unit for forming a transmission signal including the voice signal, and a transmission unit for transmitting the transmission signal are provided.
The transmission signal further includes a first tone signal, an identification signal superimposed on the first tone signal, and a second tone signal following the first tone signal.
The audio signal is a transmission device superimposed on the second tone signal. Receives a transmission signal including a first tone signal, an identification signal superimposed on the first tone signal, a second tone signal following the first tone signal, and an audio signal superimposed on the second tone signal. It is a receiving device that
The receiving unit that receives the transmission signal, the determination unit that determines whether or not the reception signal includes an audio signal based on the reception signal received by the reception unit, and the determination unit based on the determination result of the determination unit. Equipped with an extraction unit that extracts audio signals from received signals
The determination unit detects the first tone signal from the received signal, the second detection unit that detects the second tone signal from the received signal, and the identification signal from the received signal. The determination unit includes a third detection unit, the first detection unit detects the first tone signal, the third detection unit detects the identification signal, and the second detection unit. Is a receiving device that outputs a signal for extracting an audio signal from the received signal to the extraction unit after the detection of the second tone signal based on the detection of the second tone signal. The determination unit further includes an intensity determination unit for determining whether or not the intensity of the received signal is greater than the first threshold value, and a noise determination unit for determining whether or not the noise intensity is smaller than the second threshold value. ,
The determination unit determines that the intensity of the received signal is greater than the first threshold value, and the noise determination unit determines that the noise intensity is smaller than the second threshold value. Based on the fact that the first detection unit detects the first tone signal, the third detection unit detects the identification signal, and the second detection unit detects the second tone signal. 2. The receiving device according to claim 2, wherein after the detection of the second tone signal, a signal for extracting an audio signal from the received signal is output to the extraction unit. The take-out unit includes a switching unit and a filter unit.
Based on the determination result of the determination unit, the switching unit switches between an output state in which the received signal is output to the filter unit and a non-output state in which the received signal is not output to the filter unit.
The receiving device according to claim 2 or 3, wherein the filter unit removes the second tone signal from the received signal and outputs the audio signal. A wireless microphone system including the transmitting device according to claim 1 and the receiving device according to any one of claims 2 to 4.

Images