JP4438573B2 - Wireless audio apparatus and wireless audio system - Google Patents

Description

  The present invention relates to a wireless audio device that includes a transmission unit that transmits a wireless signal including audio data, a wireless audio device that includes a reception unit that receives these wireless signals, and a wireless device that includes these wireless audio devices. The audio system.

  In a conventional audio apparatus and an audio system composed of these, an audio signal or audio data is often transmitted by a wired connection such as a cable. On the other hand, audio devices using wireless (wireless) connection include those using infrared rays and those using radio signals using modulation such as FM (frequency modulation) and PSK (phase shift modulation). It may be used between a source device and a speaker device with a built-in amplifier.

In recent years, with the spread of a surround system having five or more audio signal channels, wireless connection is used for connection between an AV center as a source device and five or more speakers arranged indoors. Specifically, there is an AV center provided with a wireless transmission unit and an amplifier built-in surround speaker arranged beside or behind the viewer with a wireless reception unit. Compared with the speaker cable connection, there is no troublesome speaker cable, so there is an advantage that the arrangement becomes relatively free. As a method of wireless connection, there is typically one in which voice data is transmitted by a wireless LAN (local area network) (Patent Document 1).

JP 2001-359200 A (FIG. 1)

  However, the conventional wireless audio apparatus cannot avoid the problem of sound interruption caused by a transmission failure peculiar to the wireless system. For example, when a digital transmission method such as a wireless LAN is used, the usable frequency band including legal regulations is limited, so that it can be used with other wireless transmission devices (for example, a personal computer connected to a wireless LAN). When the transmission channels are overlapped or when a disturbing radio signal arrives, there is an adverse effect, and the radio audio apparatus has a problem that the reproduction of the audio signal is interrupted, that is, the sound is interrupted. Due to the characteristics of the audio signal, sound interruption is undesirable because it is harsh, and even if sound interruption occurs, the shorter the time, the better.

Conventionally, various measures have been taken in order to avoid a transmission failure peculiar to each wireless system. When using a digital transmission system such as a wireless LAN, the transmission data transmission channel, that is, the carrier wave frequency of the carrier wave that modulates the transmission data into a radio signal is prepared, and the used transmission channel overlaps. In such a case, there is one that attempts to solve the problem by switching to another transmission channel. In this case, if the transmission side device switches the transmission channel to another transmission channel, detection will be lost on the reception side and transmission of audio data will be interrupted, so the reception side device will detect the switched transmission channel again. There must be. Therefore, there is a problem that the reproduction of the audio signal is interrupted until the transmission channel is switched in order to confirm the reception and the transmission of the audio data is resumed.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention relates to a wireless audio apparatus and a wireless audio system, and to solve the problem of sound interruption caused by a transmission failure peculiar to a wireless system. The object of the present invention is to provide a wireless audio device and a wireless audio system that are minimized and good for the user.

A wireless audio device of the present invention is a wireless audio device including a transmission unit that transmits a wireless signal including audio data to another wireless audio device including a reception unit by packet communication , and a control unit that controls the transmission unit. The transmission unit includes a modulation unit that modulates audio data and control data from the control unit into a radio signal, and a modulation setting unit that sets a carrier frequency in the modulation unit, and the control unit has one set carrier frequency. To generate switching control data including at least information defining switching timing for switching to another different set carrier frequency, information defining other set carrier frequency, and a packet number indicating the order of packets in packet communication , The switching control data is given to the transmission unit, and the transmission unit transmits a radio signal including the switching control data.

  Preferably, in the wireless audio device of the present invention, the control unit gives a control signal for switching the set carrier frequency to a different set carrier frequency to the modulation setting unit of the transmission unit at a specified switching timing based on the switching control data. The modulation setting unit of the transmission unit switches the set carrier frequency to another set carrier frequency.

  Preferably, the wireless audio device of the present invention includes an instruction input unit connected to the control unit, the control unit receives a signal from the instruction input unit, generates switching control data, and provides the switching control data to the transmission unit. The transmitting unit transmits a radio signal including the switching control data.

  More preferably, the wireless audio apparatus of the present invention includes a wireless signal strength detection unit that is connected to the control unit and detects the strength of the wireless signal, and a display unit that is connected to the control unit, and the display unit includes: The signal from the control unit is received and the wireless signal strength is displayed.

More preferably, in the wireless audio device of the present invention, when the control unit receives a signal from the instruction input unit or when the signal level from the wireless signal strength detection unit becomes lower than a specified value, the switching control data is generated. Then, the switching control data is given to the transmitting unit, and the transmitting unit transmits a radio signal including the switching control data.

Also, wireless audio device of the present invention includes a receiving unit that receives a radio signal by packet communications sent from the wireless audio device, a reception control unit that controls the receiving unit, a reception unit, a radio signal A demodulating unit for demodulating the data into audio data and switching control data , and a demodulation setting unit for setting a carrier frequency in the demodulating unit, wherein the reception control unit switches from one set carrier frequency to another different set carrier frequency. Demodulation setting of the receiver in a specified switching timing based on switching control data including at least information specifying timing, information specifying other set carrier frequency, and packet number indicating the order of packets in packet communication A control signal for switching the set carrier frequency to a different set carrier frequency, and the demodulation setting unit of the demodulator Switching the wave number different other settings carrier frequency.

Preferably, in the wireless audio device of the present invention, the reception unit is connected to the reception control unit, and the reception signal strength detection unit that detects the strength of the received radio signal, the display unit connected to the reception control unit, The display unit receives the signal from the reception control unit and displays the received signal strength.

  More preferably, the wireless audio device of the present invention includes a transmission unit connected to the reception control unit and an instruction input unit connected to the reception control unit, and the reception control unit receives a signal from the instruction input unit. The switching control data is generated, the transmission unit transmits a radio signal including the switching control data, and the reception control unit transmits a different set carrier frequency to the demodulation setting unit at a specified switching timing based on the switching control data. A control signal for switching to the set carrier frequency is provided, and the demodulation setting unit of the demodulator switches the set carrier frequency to another set carrier frequency.

More preferably, in the wireless audio device of the present invention, the reception control unit generates the switching control data when the signal from the instruction input unit is received or when the signal level from the reception intensity detection unit becomes lower than a specified value. To do.

Preferably, the wireless audio device of the present invention further includes a receiving unit that receives a wireless signal including switching control data transmitted from the wireless audio device, and the receiving unit demodulates the wireless signal into switching control data. The switching control data is supplied to the connected control unit, and the control unit supplies the switching control data to the modulation setting unit.

Preferably, in the wireless audio device of the present invention, the information defining the switching timing included in the switching control data is time information equal to a relative time from when the switching control data is generated until the set carrier frequency is switched, or Contains time information equal to the absolute time to switch the set carrier frequency.

Preferably, the wireless audio system of the present invention includes the plurality of wireless audio devices described above.

  The operation of the present invention will be described below.

  The wireless audio system of the present invention is composed of a wireless audio device on the transmission side, and other wireless audio devices on the reception side. These wireless audio devices transmit a radio signal including audio data, prepare a carrier frequency of a carrier wave that modulates the transmission data into a radio signal, that is, prepare a plurality of data transmission channels, and overlap the used transmission channels. If this occurs, switch to another transmission channel. At this time, the wireless audio apparatus of the present invention can minimize the problem of sound interruption by the action described below.

The transmission-side wireless audio device includes a transmission unit that transmits a radio signal including audio data to another wireless audio device that includes a reception unit, and a control unit that controls the transmission unit. A modulation unit that modulates control data from the control unit into a radio signal; and a modulation setting unit that sets a carrier frequency in the modulation unit. The modulation setting unit sets a carrier frequency that means a transmission channel, and switches the transmission channel to another transmission channel according to the control unit.

The reception-side radio audio apparatus includes a reception unit that receives a radio signal and a reception control unit that controls the reception unit, and the reception unit demodulates the radio signal into audio data and switching control data. And a demodulation setting unit for setting a carrier frequency in the demodulation unit meaning a transmission channel.

The control unit of the wireless audio device on the transmission side includes switching control data including at least information defining a switching timing for switching from one set carrier frequency to another set carrier frequency and information defining another set carrier frequency. The switching control data is generated and given to the transmission unit, and the transmission unit transmits a radio signal including the switching control data. In addition, the control unit gives a control signal for switching the set carrier frequency to a different set carrier frequency to the modulation setting unit of the transmission unit at a specified switching timing based on the switching control data, and the modulation setting unit of the transmission unit The set carrier frequency is switched to a different set carrier frequency. In addition, the reception control unit of the wireless audio device on the receiving side gives a control signal for switching the set carrier frequency to a different set carrier frequency to the demodulation setting unit of the reception unit to the switching time specified based on the switch control data, The demodulation setting unit of the demodulation unit switches the set carrier frequency to another set carrier frequency.

That is, the control unit of the wireless audio device on the transmission side performs switching including information defining a switching timing indicating timing (timing, timing, time) for switching the transmission channel to another transmission channel and information on the other transmission channel to be switched. Generate control data. The control unit provides the switching control data to the transmitting unit, the transmitting unit transmits a radio signal including the switching control data, and the control unit transmits the transmission channel of the transmitting unit to a specified switching timing based on the switching control data. Change the setting to another transmission channel. Therefore, in the wireless audio device that has received the transmitted wireless signal, the reception control unit can switch the transmission channel to another transmission channel at the switching timing defined based on the switching control data included in the wireless signal. As a result, the transmission channel of the wireless audio device on the transmission side and the reception side can be switched almost simultaneously, so that the problem of sound interruption caused by the change of the transmission channel can be minimized.

  Various methods can be adopted for the information specifying the switching timing included in the switching control data depending on the configuration of the wireless audio device, but the time equal to the relative time from when the switching control data is generated until the set carrier frequency is switched. Any information including information (for example, when switching after 0.1 second) may be used. Alternatively, it may include time information equal to the absolute time for switching the set carrier frequency (for example, when switching to a designated 0 hour 0 minute 0 second). As a result, the transmission channels of the transmission side and reception side wireless audio apparatuses can be switched almost simultaneously.

  The information defining the switching timing included in the switching control data may include a packet number indicating the order of packets in packet communication. That is, a packet number indicating a packet to be switched (switching target packet) may be included. Since the wireless audio devices on the transmission side and the reception side constantly monitor the packet number in packet communication, it is possible to switch the transmission channel almost simultaneously by determining that it is a packet to be switched.

  Preferably, the wireless audio apparatus of the present invention includes an instruction input unit connected to a control unit on the transmission side, and the control unit receives a signal from the instruction input unit, generates switching control data, and transmits the switching control data. The transmission unit transmits a radio signal including the switching control data. Therefore, the user who has detected the failure of the transmission channel in the reproduction state of the audio signal can arbitrarily switch the transmission channel on the transmission side according to the intention of the user.

  More preferably, the wireless audio device of the present invention is connected to the control unit on the transmission side and displays the wireless signal strength by receiving a signal from the control unit and a wireless signal strength detection unit that detects the strength of the wireless signal. A display unit is provided. In the wireless audio device of the present invention, the reception unit is connected to the reception control unit, and the reception signal strength detection unit that detects the strength of the received radio signal, and the display unit that is connected to the reception control unit, The display unit receives the signal from the reception control unit and displays the received signal strength. Therefore, the user can easily determine whether the radio signal strength or the received signal strength displayed on the display unit on the transmission side or the reception side is insufficient.

More preferably, in the wireless audio device of the present invention, when the control unit on the transmission side receives a signal from the instruction input unit or the signal level from the wireless signal strength detection unit becomes lower than a specified value, the switching control is performed. Data is generated, switching control data is given to the transmission unit, and the transmission unit transmits a radio signal including the switching control data. In the wireless audio device of the present invention, it is preferable that the reception control unit receives the signal from the instruction input unit or the switching control data when the signal level from the reception intensity detection unit becomes lower than a specified value. The transmitting unit transmits a wireless signal including the switching control data. Therefore, when a failure occurs in the transmission channel of the radio signal, the transmission channel can be changed arbitrarily or automatically, so that the problem of sound interruption caused by the change of the transmission channel can be further reduced.

Preferably, the wireless audio apparatus according to the present invention includes a transmission unit connected to the reception control unit and an instruction input unit connected to the reception control unit, and the reception control unit switches in response to a signal from the instruction input unit. Control data is generated, and the transmission unit transmits a radio signal including the switching control data. Therefore, when the user determines that the radio signal strength displayed on the display unit is insufficient, the transmission channel can be arbitrarily switched on the receiving side according to the user's intention.

Preferably, the wireless audio device of the present invention further includes a receiving unit that receives a wireless signal including switching control data transmitted from the wireless audio device, and the receiving unit demodulates the wireless signal into switching control data. The switching control data is supplied to the control unit to be connected, the control unit generates the switching control data based on the switching control data, the switching control data is supplied to the modulation setting unit, and the transmission unit is a radio signal including the switching control data. Send. Accordingly, the switching control data transmitted from the reception-side wireless audio device, that is, the transmission-side wireless audio device gives an instruction to change the transmission channel by the user or automatically transmitted from the reception-side wireless audio device. The transmission channel can be changed more appropriately.

  The wireless audio apparatus and the wireless audio system of the present invention can provide a wireless audio apparatus and a wireless audio system that are good for the user by minimizing the problem of sound interruption caused by transmission failure peculiar to the wireless system.

  A wireless audio device of the present invention is a wireless audio device including a transmission unit that transmits a wireless signal including audio data to another wireless audio device that includes a reception unit, and a control unit that controls the transmission unit. A modulation unit that modulates audio data and control data from the control unit into a radio signal, and a modulation setting unit that sets a carrier frequency in the modulation unit, and the control unit is different from one set carrier frequency. Switching control data including at least information for specifying a switching timing for switching to the set carrier frequency and information for specifying another set carrier frequency is generated, and the switching control data is provided to the transmission unit, and the transmission unit provides the switching control data. This is realized by transmitting a radio signal including

  Hereinafter, a wireless audio apparatus and a wireless audio system according to preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram illustrating a wireless audio system 1 according to a preferred embodiment of the present invention. The wireless audio system 1 includes an AV center 2, speakers 3L, 3C and 3R, and amplifier built-in speakers 4LS and 4RS. The AV center 2 and the speakers 3L, 3C and 3R are wiredly connected by speaker cables. The center 2 and the amplifier built-in speakers 4LS and 4RS are wirelessly connected by radio signals. That is, in this embodiment, the amplifier built-in speakers 4LS and 4RS corresponding to the surround channel are wirelessly connected, so that when the speaker cable is placed in the lateral direction or the rear of the listener far away from the AV center 2, the speaker cable There is an advantage that is not controlled by the length.

In the AV center 2, a digital audio signal encoded with a multi-channel surround signal is input to the signal input 9 from a DVD (Digital Versatile Disc) playback device or the like. This digital audio signal is decoded by the decoder 6 into a left channel signal L, a center channel signal C, a right channel signal R, a left surround channel signal LS, and a right surround channel signal RS. The decoded signal of each channel is supplied to a corresponding speaker arranged in the surround sound field to provide the user with a surround sound field. The AV center 2 includes a main microcomputer 5. The main microcomputer 5 controls the AV center 2 and the entire wireless audio system 1.

Specifically, the left channel signal L, the center channel signal C, or the right channel signal R is supplied to the speakers 3L, 3C, or 3R via output circuits 7L, 7C, or 7R each including a D / A converter and an amplifier, respectively. The Further, the left surround channel signal LS or the right surround channel signal RS is supplied to the transmission circuit 10LS or 10RS, respectively. The transmission circuit 10LS or 10RS modulates the supplied surround channel signal, that is, digital audio data, into a radio signal and transmits it. The amplifier built-in speaker 4LS or 4RS includes a reception circuit 20LS or 20RS, respectively. The left surround channel signal LS or the right surround channel signal RS received as a radio signal is an output circuit 7LS or 7RS including a D / A converter and an amplifier. And then supplied to the speaker unit 8LS or 8RS.

FIG. 2 is a diagram illustrating a transmission circuit 10 and a reception circuit 20 corresponding to one audio channel signal according to a preferred embodiment of the present invention. The transmission circuit 10 includes a wireless transmission unit 11, a microcomputer 12 that controls the wireless transmission unit 11, and an instruction button 17 that detects a user (user) operation. The reception circuit 20 includes a wireless reception unit 21 and a microcomputer 22 that controls the wireless reception unit 21. Specifically, the wireless transmission unit 11 is a packet wireless transmission module that converts digital audio data into a packet communication signal, further modulates this into a wireless signal, and outputs it. The wireless reception unit 21 receives a wireless signal. It is a packet radio reception module that demodulates in this way. That is, the digital audio data is transmitted from the packet radio transmission module 11 to the packet radio reception module 21. Typically, the modulation method of the radio signal is PSK (phase shift keying) or SS (spread spectrum), and the frequency band of the carrier wave to be modulated is 2.4 GHz band or 5 Hz band. A plurality of transmission channels having different frequencies are set. For example, in the legally regulated 2.4 GHz band, the carrier frequency is selected within the permitted frequency band. Note that these modules may use a packet radio module having both transmission and reception functions by selecting the transmission or reception function. In addition, the noise source 40 represents another wireless transmission device (for example, a personal computer connected to a wireless LAN) that causes the duplication of the transmission channel being used or a wireless signal that causes disturbance.

The packet radio transmission module 11 includes a packet processing circuit 13 that converts input digital audio data into a packet signal, a modulation circuit 15 that modulates the packet signal into a radio signal, an antenna 16 that outputs a radio signal, and a modulation circuit 15. And a modulation setting circuit 14 for setting the carrier wave frequency in FIG. Further, the microcomputer 12 is connected to the instruction button 17 and controls the transmission circuit 10. On the other hand, the packet radio reception module 21 includes an antenna 26 that receives a radio signal, a demodulation circuit 25 that demodulates the radio signal, a packet decoding circuit 23 that converts the demodulated packet signal into digital audio data, and a demodulation circuit 25. A demodulation setting circuit 24 for setting the carrier frequency is provided and connected to the microcomputer 22. The microcomputer 22 is further connected to a received signal strength detection circuit 29 that detects the strength of the received radio signal and a display circuit 28 that displays the received signal strength, and the microcomputer 22 controls the receiving circuit 20.

FIG. 3 is a diagram schematically illustrating packet data transmitted by packet wireless communication between the transmission circuit 10 and the reception circuit 20 of the present invention. One packet data is composed of a packet header, control data, and audio data. The packet header indicates the head of the packet and includes a packet number indicating the order of the packets. The audio data includes digital audio data necessary for audio reproduction of a certain unit time, and constitutes one packet in combination with control data transmitted within the unit time. Here, the control data includes other control data, and further includes information defining a switching timing for switching from one set carrier frequency to another set carrier frequency, and information defining another set carrier frequency. The switching control data including at least is included. That is, the control data includes information for defining a switching timing indicating timing (timing, timing, time) for switching a transmission channel to another transmission channel, and switching control data including information on other transmission channels to be switched. Yes.

FIG. 4 is a flowchart for explaining the operation of the transmission circuit 10 and the reception circuit 20 of this embodiment. In this embodiment, audio data is packet-transmitted from the transmission circuit 10 to the reception circuit 20 (packet transmission: S101, packet reception: S201). When a problem such as sound interruption occurs due to the duplication of transmission channels used due to the influence of the noise source 40 or the like, when the user presses the instruction button 17 to solve this problem, the transmission channel switching operation is performed. The instruction is determined by the microcomputer 12 that controls the transmission circuit 10 (S102), and switching control data is generated. Specifically, the packet number for switching the channel and another transmission channel are determined (S103). The microcomputer 12 gives the switching control data to the packet radio transmission module 11, and the packet radio transmission module 11 transmits a radio signal including the switching control data (S104). After repeatedly transmitting a predetermined number of times (S105), the microcomputer 12 further switches the transmission channel setting of the transmission unit to another transmission channel at a specified switching time based on the switching control data. Specifically, after continuing the normal packet transmission process (S106), the microcomputer 12 determines whether the packet is switched from the packet number of the packet to be transmitted (switching target packet). An instruction to switch the transmission channel is given to the modulation setting circuit 14 (S107).

On the other hand, the microcomputer 22 that controls the receiving circuit 20 always monitors the packet header and control data of the packet data. When the packet radio reception module 21 receives the packet including the switching control data (S202), the microcomputer 22 determines the packet number of the switching target packet to be switched and other transmission channels to be switched based on the switching control data from the demodulated control data. Determine (S203). Therefore, normal reception is continued until the packet number included in the packet data becomes the packet number of the switching target packet (S204), and if the next packet is received as a switching target packet (S205), the packet After the above processing is performed, the transmission channel is switched to another determined transmission channel (S206). Specifically, the microcomputer 22 gives an instruction to switch to another transmission channel to the demodulation setting circuit 24, and the carrier frequency in the demodulation circuit 25 is switched to another carrier frequency.

Therefore, in the transmission circuit 10 and the reception circuit 20 of the present invention, the microcomputer 12 and the microcomputer 22 can switch the transmission channel to another transmission channel at the switching time specified by the packet number of the packet to be switched. As a result, since the transmission channel between the transmission circuit 10 and the reception circuit 20 can be switched almost simultaneously, it is possible to minimize the problem of sound interruption caused by the change of the transmission channel.

The reception circuit 20 includes a reception signal strength detection circuit 29 that detects the strength of the received radio signal and a display circuit 28 that is connected to the microcomputer 22, so that the display circuit 28 receives a signal from the microcomputer 22 and receives a received signal. Display strength. When a problem such as sound interruption occurs due to the influence of the noise source 40 or the like, the user not only detects the sound reproduction state by audibility but also observes the received signal strength of the display circuit 28 and The instruction button 17 may be pressed. Note that the transmission channel switching instruction determined by the microcomputer 12 of the transmission circuit 10 (S102) is not limited to the case where the user presses the instruction button 17 of the transmission circuit 10. When an instruction to switch the transmission channel is given to the main microcomputer 5 (not shown) that controls the AV center 2 by another remote control circuit or the like, the main microcomputer 5 instructs the microcomputer 12 of the transmission circuit 10 to switch the transmission channel again. May be given.

  In this embodiment, the audio signal data is configured as a packet, and the timing for switching the transmission channel is defined in units of packets. However, the information specifying the switching timing included in the switching control data is the packet number of the switching target packet. Any information including relative time or absolute time information defined between the transmission circuit 10 and the reception circuit 20 may be used. Also, as time information equal to the relative time from when the switching control data is generated by the microcomputer 12 to when the set carrier frequency is switched, for example, when switching after 0.1 second, data including “0.1 second” is included. Or may include data “after 1000 packets”. In this case, the relative time information transmitted decreases as the specified switching time approaches. Further, when the transmission between the transmission circuit 10 and the reception circuit 20 takes a stream configuration, as the absolute time information for switching the transmission channel, for example, when switching to the designated 0 hour 0 minute 0 second, the microcomputer 12 It may include time information that is equal to the time information transmitted by the internal clock. The microcomputer 22 of the receiving circuit 20 may extract the above switching timing information from the received switching control data and compare it with an internal clock possessed by the microcomputer 22.

When the microcomputer 12 determines another transmission channel to be switched from one transmission channel, the transmission channel with the farthest carrier frequency is preferentially selected in order to prevent duplication of the transmission channel. When one of the transmission circuits 10 of the present invention, for example, the transmission circuit 10LS switches from one transmission channel to another transmission channel, the microcomputer 12 of the transmission circuit 10LS is used in the transmission circuit 10RS of the AV center 2. Based on information from the main microcomputer 5, another transmission channel is determined so as not to overlap the transmission channel. Similarly, if there are other transmission channels that are known and used, the transmission channels should not overlap.

Furthermore, in the present embodiment, the transmission circuit 10LS or 10RS is a transmission circuit having different transmission channels, that is, having different carrier frequencies, but a plurality of left surround channel signals LS and right surround channel signals RS are transmitted by one transmission circuit. May be sent. The multi-channel surround signals may be separated by the amplifier amplifier speaker on the reception side, and only the channel corresponding to the surround sound field at the position where the amplifier speaker is arranged may be selected.

Furthermore, in this embodiment, the wireless connection of the present invention is applied to surround speakers in multi-channel surround, but is not limited to only surround channels. You may apply to transmission of the audio | voice signal containing the multichannel surround signal by the wireless connection of AV center 2 and another AV apparatus.

FIG. 5 is a diagram illustrating a transmission circuit 10 and a reception circuit 20 according to another preferred embodiment of the present invention. In FIG. 5, the description of the parts common to the first embodiment described in FIG. 2 is omitted.

The transmission circuit 10 includes a packet radio transmission module 11, a microcomputer 12 that controls the packet radio transmission module 11, and an instruction button 17, and is further connected to the microcomputer 12 and detects a radio signal intensity. An intensity detection circuit 19 and a display circuit 18 connected to the microcomputer 12 are provided. The display circuit 18 receives the signal from the microcomputer 12 and displays the wireless signal strength. Further, the microcomputer 12 receives the signal from the instruction button 17 and the signal from the wireless signal strength detection circuit 19, and generates the switching control data when the signal level from the wireless signal strength detection circuit 19 becomes lower than the specified value. The switching control data is given to the packet radio transmission module 11, and the packet radio transmission module 11 transmits a radio signal including the switching control data.

  Therefore, when there is a duplication of transmission channels used due to the influence of the noise source 40 or the like, and a problem such as sound interruption occurs, the user looks at the display circuit 18 of the transmission-side device provided with the transmission circuit 10. Thus, it can be determined whether the radio signal strength is insufficient. When the user presses the instruction button 17, the microcomputer 12 generates switching control data and switches the transmission channel to solve the problem of sound interruption. Further, not only the instruction from the user, but when the signal level from the wireless signal strength detection circuit 19 becomes lower than the specified value, the microcomputer 12 may automatically generate the switching control data and switch the transmission channel.

The receiving circuit 20 according to another preferred embodiment of the present invention shown in FIG. 5 includes a packet radio reception module 21, a microcomputer 22 that controls the packet radio reception module 21, and an instruction button 27 that is connected to the microcomputer 22. Further, a reception signal strength detection circuit 29 that detects the strength of the received radio signal and a display circuit 28 that displays the reception signal strength are connected to the terminal 22. The packet radio reception module 21 functions as a packet radio transmission module by switching transmission / reception functions in a time division manner. On the other hand, the packet radio transmission module 11 of the transmission circuit 10 in FIG. 5 also functions as a packet radio reception module by switching the transmission / reception function. Therefore, when the microcomputer 22 receives the signal from the instruction button 27 or when the signal level from the reception intensity detection circuit 29 becomes lower than the specified value, it generates the switching control data, and the packet radio reception module 21 A radio signal including control data is transmitted. The packet radio transmission module 11 demodulates the radio signal into the switching control data, gives the switching control data to the microcomputer 12 connected, the microcomputer 12 gives the switching control data to the modulation setting circuit 14, and the packet radio transmission module 11 A radio signal including switching control data is transmitted.

Therefore, if the user determines that the received signal strength represented by the display circuit 28 detected by the received signal strength detection circuit 29 of the receiving circuit 20 is insufficient, the transmission channel can be arbitrarily selected on the receiving side according to the user's intention. Can be switched. In this embodiment, since the transmission channel can be switched on the side of a device such as a surround speaker provided with the receiving circuit 20, the user can select the sound from the indication of the reception intensity and the state of the reproduced audio signal. There is an advantage that it is easy to judge the cut.

When the microcomputer 22 determines that the received signal strength is insufficient, the receiving circuit 20 of this embodiment can automatically instruct switching of the transmission channel on the receiving side. FIG. 6 is a flowchart for explaining the operation when the receiving circuit 20 automatically gives a transmission channel switching instruction in the transmitting circuit 10 and the receiving circuit 20 of this embodiment. In this embodiment, audio data is packet-transmitted from the transmission circuit 10 to the reception circuit 20 (packet transmission: S111, packet reception: S211). When duplication of transmission channels used due to the influence of the noise source 40 or the like occurs and a problem such as sound interruption occurs, the microcomputer 22 determines that the received signal strength is below the reference value (S212) and below the reference value. If it is determined that the state continues for a certain time (S213), switching control data is generated. Specifically, the packet number for switching the channel and another transmission channel are determined (S214). The microcomputer 22 gives the switching control data to the packet radio reception module 21, and the packet radio reception module 21 switches the transmission / reception function and transmits a radio signal including the switching control data (S215). The microcomputer 22 repeatedly transmits a predetermined number of times (S216), and then switches the transmission / reception function of the packet radio reception module 21 again to perform normal packet reception processing (S217).

On the other hand, when the packet radio transmission module 11 of the transmission circuit 10 receives the packet including the switching control data (S112), the microcomputer 12 determines the packet number of the switching target packet to be switched and other switching based on the demodulated switching control data. Determine the transmission channel. Then, normal transmission is continued until the packet number of the packet to be transmitted becomes the packet number of the switching target packet (S113), and when it is determined that the next packet is a packet to be switched (S114). Then, the transmission channel is switched to another determined transmission channel (S115). Specifically, the microcomputer 12 gives an instruction to switch to another transmission channel to the modulation setting circuit 14, and the carrier frequency in the modulation circuit 15 is switched to another carrier frequency.

The microcomputer 22 that controls the receiving circuit 20 always monitors the packet header and control data of the packet data, and switches the setting of the transmission channel of the receiving circuit 20 to another transmission channel at a specified switching time based on the switching control data. . Specifically, the microcomputer 22 continues normal reception until the packet number included in the packet data becomes the packet number of the switching target packet (S217), and receives the packet in which the next packet becomes the switching target packet. If the packet is processed (S218), the packet is switched to another determined transmission channel (S219). Specifically, the microcomputer 22 gives an instruction to switch to another transmission channel to the demodulation setting circuit 24, and the carrier frequency in the demodulation circuit 25 is switched to another carrier frequency.

If the microcomputer 22 determines that the received signal strength is below the reference value (S212), the microcomputer 22 counts the number of times the state below the reference value is shown, not only when the state below the reference value continues for a certain period of time. If it is determined that the number of times has reached the specified number of times within a certain time (S213), switching control data may be generated (S214). Of course, not only when the microcomputer 22 automatically determines, but the microcomputer 22 determines that the user has pressed the support button 27 in order to switch the transmission channel by detecting a problem such as sound interruption and the switching control data. May be generated (S214).

Therefore, in the transmission circuit 10 and the reception circuit 20 of the present invention, the transmission channel is switched to another transmission channel at the switching timing specified by the packet number of the packet to be switched by operation from the transmission side or from the reception side or automatic determination. be able to. As a result, the transmission channel between the transmission circuit 10 and the reception circuit 20 can be switched almost simultaneously. It is possible to minimize the problem of sound interruption caused by the change of the transmission channel, which increases convenience for the user.

  The switching control data transmitted by the packet radio reception module 21 of the receiving circuit 20 is not limited to data including the packet number for switching channels and other determined transmission channels. The switching control data only needs to include at least a status instructing switching of the transmission channel, and the microcomputer 12 of the transmission circuit 10 that has received the radio signal including the switching control data determines the packet number to be switched and other transmission channels. May be. In that case, the microcomputer 12 may generate switching control data again, give the switching control data to the packet radio transmission module 11 of the transmission circuit 10, and the packet radio transmission module 11 may transmit a radio signal including the switching control data. .

  The wireless audio apparatus and the wireless audio system of the present invention are not limited to between the AV center and the speaker with a built-in amplifier, but can be applied to AV devices such as other amplifiers, electrical and electronic devices, and personal computers. It is. The transmitted audio data is not limited to audio but may be accompanied by video data, and is particularly suitable for video / audio distribution in a wireless transmission system.

1 is a diagram illustrating a wireless audio system according to a preferred embodiment of the present invention. Example 1 It is a figure explaining the transmission circuit and receiving circuit by preferable embodiment of this invention. Example 1 It is a figure which illustrates typically the packet data transmitted by the packet radio | wireless communication between the transmission circuit of this invention, and a receiving circuit. Example 1 3 is a flowchart illustrating operations of a transmission circuit and a reception circuit according to the present invention. Example 1 It is a figure explaining the transmission circuit by other preferable embodiment of this invention, and a receiving circuit. (Example 2, Example 3) 3 is a flowchart illustrating operations of a transmission circuit and a reception circuit according to the present invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wireless audio system 2 AV center 3 Speaker 4 Amplifier built-in speaker 5 Main microcomputer 6 Decoder 7 Output circuit 8 Speaker unit 9 Signal input 10 Transmission circuit 11 Wireless transmission part, packet wireless transmission module 12 Microcomputer 13 Packet processing circuit 14 Modulation setting circuit 15 Modulation circuit 16 Antenna 17 Instruction button 18 Display circuit 19 Radio signal strength detection circuit 20 Reception circuit 21 Radio reception unit, packet radio reception module 22 Microcomputer 23 Packet decoding circuit 24 Demodulation setting circuit 25 Demodulation circuit 26 Antenna 27 Instruction button 28 Display circuit 29 Received signal strength detection circuit 40 Noise source

Claims (12)

A wireless audio device comprising: a transmission unit that transmits a wireless signal including audio data by packet communication to another wireless audio device including a reception unit; and a control unit that controls the transmission unit,
The transmission unit includes a modulation unit that modulates audio data and control data from the control unit into a radio signal, and a modulation setting unit that sets a carrier frequency in the modulation unit,
Information for defining a switching timing at which the control unit switches from one set carrier frequency to another set carrier frequency, information for defining the other set carrier frequency, and a packet number indicating the order of packets in the packet communication And switching control data including at least the switching control data is provided to the transmission unit,
The transmitter transmits a radio signal including the switching control data;
Wireless audio device. The control unit gives a control signal for switching a set carrier frequency to the different set carrier frequency to the modulation setting unit of the transmission unit at the specified switching timing based on the switching control data,
The modulation setting unit of the transmission unit switches a set carrier frequency to the different set carrier frequency;
The wireless audio apparatus according to claim 1. An instruction input unit connected to the control unit;
The control unit receives the signal from the instruction input unit, generates switching control data, and provides the switching control data to the transmission unit,
The transmitter transmits a radio signal including the switching control data;
The wireless audio apparatus according to claim 1 or 2. A wireless signal strength detection unit connected to the control unit and detecting the strength of the wireless signal; and a display unit connected to the control unit;
The wireless audio apparatus according to claim 1, wherein the display unit receives a signal from the control unit and displays a wireless signal strength. When the control unit receives a signal from the instruction input unit or when the signal level from the wireless signal strength detection unit becomes lower than a specified value, the control unit generates the switching control data, and the switching control data is To the transmitter,
The transmitter transmits a radio signal including the switching control data;
The wireless audio apparatus according to claim 1. A wireless audio device comprising: a reception unit that receives a wireless signal by packet communication transmitted from a wireless audio device; and a reception control unit that controls the reception unit,
The receiving unit is provided with a demodulator for demodulating the wireless signal to the audio data and the switching control data, a demodulator setting unit that sets a carrier frequency in the demodulation unit, and
A packet indicating the order of packets in the packet communication , information defining a switching timing when the reception control unit switches from one set carrier frequency to another different set carrier frequency, information defining the other set carrier frequency, and number and, in a based on at least including the switching control data defined the switching time, provides a control signal for switching the setting carrier frequency to the demodulation setting of the receiver to the different other settings carrier frequency,
The demodulation setting unit of the demodulation unit switches the set carrier frequency to the different other set carrier frequency;
Wireless audio device. The reception unit includes a reception signal strength detection unit that is connected to the reception control unit and detects the strength of the received radio signal, and a display unit that is connected to the reception control unit,
The display unit receives a signal from the reception control unit and displays a received signal strength.
The wireless audio apparatus according to claim 6. A transmission unit connected to the reception control unit, and an instruction input unit connected to the reception control unit,
The reception control unit receives the signal from the instruction input unit and generates switching control data,
The transmitter transmits a radio signal including the switching control data;
The reception control unit gives a control signal for switching a set carrier frequency to the different set carrier frequency to the demodulation setting unit at a specified switching timing based on the switching control data,
The demodulation setting unit of the demodulation unit switches the set carrier frequency to the different other set carrier frequency;
The wireless audio apparatus according to claim 7. The reception control unit receives the signal from the instruction input unit, or generates the switching control data when the signal level from the reception intensity detection unit is lower than a specified value.
The wireless audio apparatus according to claim 8. The wireless audio device according to any one of claims 1 to 5, further comprising a receiving unit that receives a wireless signal including the switching control data transmitted from the wireless audio device.
The receiving unit demodulates the radio signal into switching control data, and supplies the switching control data to the control unit connected;
The control unit provides the switching control data to the modulation setting unit;
Wireless audio device. The information defining the switching timing included in the switching control data is time information equal to the relative time from when the switching control data is generated to when the set carrier frequency is switched, or absolute time when the set carrier frequency is switched. Contains equal time information,
The wireless audio apparatus according to claim 1. A plurality of the wireless audio devices according to any one of claims 1 to 11,
Wireless audio system.

Images