JP7698482B2 - SOUND OUTPUT SYSTEM, SOUND OUTPUT CONTROL DEVICE, AUDIO DEVICE, AND AUDIO CONNECTION SWITCHING METHOD - Google Patents

Description

The present invention relates to a sound output system, a sound output control device, an audio device, and an audio connection switching method.

Conventionally, devices are known that connect an audio device capable of outputting sound to a television receiver (hereinafter also referred to as "television") and switch the sound output destination between the television and the audio device. For example, Patent Document 1 discloses a device that switches the sound output destination between a television and headphones as an audio device. When the device disclosed in Patent Document 1 detects that headphones are being worn, it switches the sound output destination to the headphones and mutes the television so that sound is not output from the television's speakers.

JP 2013-051532 A

Conventionally, as in the device disclosed in Patent Document 1, for example, only one external device connected to a television set could function as an audio device that outputs sound. However, in recent years, with the emergence of a variety of audio devices such as speakers, there have been cases where different audio devices are connected to a television set and different audio devices are used to output sound depending on the situation. In addition, when switching the sound output destination between multiple audio devices, the switching operation can become cumbersome.

The present disclosure has been made in consideration of the above-mentioned problems. The purpose of the present disclosure is to provide a sound output system, a sound output control device, an audio device, and an audio connection switching method that can easily switch the sound output destination between multiple external audio devices connected to the sound output control device.

A sound output system according to one embodiment of the present disclosure includes a sound output control device and a plurality of audio devices including a first audio device and a second audio device communicatively connected to the sound output control device, and the sound output control device outputs sound from an audio device among the plurality of audio devices with which an audio connection with the sound output control device has been established, and when the first audio device has established its audio connection with the sound output control device and the second audio device has not established its audio connection with the sound output control device, when the second audio device detects that the power of the second audio device has been turned on, the second audio device transmits a query command inquiring as to whether or not there is an audio device with which the audio connection has been established, and In response to the inquiry command, the first audio device transmits an answer command to the second audio device indicating that there is an audio device with which the audio connection is established, and the second audio device transmits a change command to instruct a change of the audio device with which the audio connection is established based on receiving the answer command, the first audio device releases the audio connection with the sound output control device based on receiving the change command, and transmits a release command to the second audio device notifying the second audio device that the audio connection has been released based on releasing the audio connection, and the second audio device executes a process to establish the audio connection with the sound output control device based on receiving the release command.

A sound output control device according to one embodiment of the present disclosure is a sound output control device that is communicatively connected to a plurality of audio devices including a first audio device and a second audio device, and includes a control unit that transmits a signal of a sound to be output to an audio device among the plurality of audio devices that has established an audio connection with the sound output control device, and when the first audio device has established the audio connection with the sound output control device and the second audio device has not established the audio connection with the sound output control device, the control unit establishes the audio connection with the second audio device based on the second audio device having executed a process for establishing the audio connection with the sound output control device as a result of the second audio device being powered on.

A first audio device according to one embodiment of the present disclosure includes a sound output control device that outputs sound from an audio device with which an audio connection has been established, a command control unit that controls the transmission and reception of commands, and a connection control unit that controls the audio connection with the sound output control device, and when the command control unit receives a query command from a second audio device with which the audio connection has not been established to inquire as to whether or not there is an audio device with which the audio connection has been established, the command control unit transmits to the second audio device a response command indicating that there is an audio device with which the audio connection has been established, the command control unit receives a change command instructing a change of the audio device with which the audio connection has been established, the connection control unit releases the audio connection with the sound output control device based on the reception of the change command, and the command control unit transmits a release command to the second audio device notifying that the audio connection has been released based on the release of the audio connection.

A second audio device according to one embodiment of the present disclosure is a second audio device communicably connected to a sound output control device that outputs sound from an audio device with which an audio connection has been established, and includes a power detection unit that detects when the power is on, a command control unit that controls the transmission and reception of commands, and a connection control unit that controls the audio connection with the sound output control device. When the power detection unit detects that the power is on, the command control unit transmits a query command inquiring as to whether or not there is an audio device with which the audio connection has been established, and based on receiving a response command in response to the query command indicating that there is a first audio device with which the audio connection has been established, the command control unit transmits a change command instructing a change of the audio device with which the audio connection has been established, and based on receiving a release command notifying that the first audio device has released the audio connection, the connection control unit executes a process for establishing the audio connection with the sound output control device.

An audio connection switching method according to one embodiment of the present disclosure is an audio connection switching method executed by a sound output system, the audio connection switching method comprising a sound output control device and a plurality of audio devices, including a first audio device and a second audio device, communicably connected to the sound output control device, and the sound output control device causes an audio device among the plurality of audio devices that is audio-connected to the sound output control device to output sound, the audio connection switching method including the steps of: transmitting an inquiry command inquiring whether or not there is an audio device with which the audio connection is established when the second audio device detects that the second audio device has been powered on, in a state in which the first audio device has established an audio connection with the sound output control device and the second audio device has not established an audio connection with the sound output control device; The method includes a step in which the first audio device transmits to the second audio device, in response to the inquiry command, a response command indicating that there is an audio device with which the audio connection is established; a step in which the second audio device transmits a change command instructing a change of the audio device with which the audio connection is established based on receiving the response command; a step in which the first audio device releases the audio connection with the sound output control device based on receiving the change command, and transmits a release command to the second audio device notifying the release of the audio connection based on releasing the audio connection; and a step in which the second audio device executes a process to establish the audio connection with the sound output control device based on receiving the release command.

1 is a diagram showing a schematic configuration of a sound output system according to a first embodiment. 2 is a functional block diagram showing an example of the configuration of the sound output system of FIG. 1; 3 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 2. 3 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 2. 3 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 2. 3 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 2. 3 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 2. FIG. 6 is a sequence diagram showing a modified example of the sequence of FIG. 5 . FIG. 11 is a functional block diagram showing an example of the configuration of a sound output system according to a second embodiment. 10 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 9 . 10 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 9 . 10 is a sequence diagram showing an example of a process performed by the sound output system of FIG. 9 .

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the drawings, identical or equivalent components are given the same reference numerals, and duplicate descriptions of identical or equivalent components will be omitted as appropriate.

[First embodiment]
Fig. 1 is a diagram showing a schematic configuration of a sound output system 1 according to a first embodiment. As shown in Fig. 1, the sound output system 1 according to the first embodiment includes a television 30 and a plurality of audio devices. In the example shown in Fig. 1, the sound output system 1 includes two audio devices, a first audio device 10 and a second audio device 20, as the plurality of audio devices. However, the number of the plurality of audio devices included in the sound output system 1 is not limited to two. The sound output system 1 may include three or more audio devices.

The first audio device 10 and the second audio device 20 are connected to the television 30 so as to be able to communicate with each other. Here, being able to communicate specifically includes being able to send and receive commands. A command is a signal that notifies specific information or instructs the execution of specific processing. In this embodiment, the first audio device 10, the second audio device 20, and the television 30 send and receive CEC (Consumer Electronics Control) commands. The specific content of the CEC commands that are sent and received will be described later.

In this embodiment, the first audio device 10 and the second audio device 20 are connected to the television 30 via HDMI (High-Definition Multimedia Interface) (registered trademark). That is, the first audio device 10, the second audio device 20, and the television 30 each have an HDMI terminal. The HDMI terminal of the first audio device 10 is connected to the HDMI terminal of the television 30 via an HDMI cable. Similarly, the HDMI terminal of the second audio device 20 is connected to the HDMI terminal of the television 30 via an HDMI cable. As a result, the television 30 is connected to the first audio device 10 and the second audio device 20 so as to be able to send and receive CEC commands. As a result, the first audio device 10 and the second audio device 20 are also able to send and receive CEC commands via the television 30.

In this embodiment, the first audio device 10 and the second audio device 20 are devices capable of outputting sound. For example, the first audio device 10 is a sound bar. The sound bar is a rod-shaped speaker. The sound bar is placed, for example, in front of the television 30. For example, the second audio device 20 is a neck speaker. The neck speaker is a speaker that is worn on the shoulder by a user watching the television 30. The neck speaker is also called a shoulder speaker, a neck speaker, or a wearable speaker. Note that the form of the audio device is not limited to the example shown here. For example, both the first audio device 10 and the second audio device 20 may be sound bars. In addition, any other speaker may be used as the audio device in this embodiment.

In this embodiment, the television 30 functions as a sound output control device. The television 30 as a sound output control device can output sound from one of a plurality of audio devices. Specifically, the television 30 as a sound output control device outputs sound from one of a plurality of audio devices with which an audio connection with the television 30 has been established. In this embodiment, the television 30 transmits a signal of the sound to be output (hereinafter also referred to as an "audio signal") to the audio device with which an audio connection with the television 30 has been established, of the first audio device 10 and the second audio device 20 connected via HDMI. As a result, the television 30 outputs sound from the audio device with which the audio connection has been established. Here, a state in which an audio connection has been established refers to a state in which a selective connection is made so that an audio signal is transmitted from the sound output control device.

In recent years, for example, as the TV 30 becomes thinner and has a narrower frame, it is difficult to incorporate a large speaker in the TV 30. Therefore, a sound bar, which is the first audio device 10, may be connected to the TV 30 and sound may be output from the sound bar. In addition, when only one user listens to sound, a shoulder speaker, which is the second audio device 20, may be connected to the TV 30 and sound may be output from the shoulder speaker. Furthermore, some users may wish to connect multiple audio devices with different purposes to the TV 30 and use different audio devices to output sound depending on the situation. In this case, it is necessary to switch which audio device outputs sound in the sound output system 1. On the other hand, when switching the sound output destination between multiple audio devices, if the switching operation is complicated, it is difficult for the user to use. The present disclosure makes it possible to easily switch the sound output destination between multiple external audio devices connected to the TV 30 as a sound output control device.

Fig. 2 is a functional block diagram showing an example of the configuration of the sound output system 1 of Fig. 1. As shown in Fig. 2, the first audio device 10 and the television 30 are connected to each other via a first HDMI cable 41 so as to be able to communicate information. Similarly, as shown in Fig. 2, the second audio device 20 and the television 30 are connected to each other via a second HDMI cable 42 so as to be able to communicate information.

As shown in FIG. 2, the first audio device 10 includes, as functional units, a first audio control unit 11, a first audio memory unit 12, a first CEC control unit 13, a first connection control unit 14, a first signal processing unit 15, a first speaker 16, a first power supply detection unit 17, and a first signal receiving unit 18.

The first audio control unit 11 controls and manages the entire first audio device 10, including each functional unit of the first audio device 10. The first audio control unit 11 includes at least one processor. The first audio control unit 11 is configured with a processor such as a CPU (Central Processing Unit) that executes a program that defines a control procedure, or a dedicated processor specialized for processing each function.

The first audio storage unit 12 is a storage medium capable of storing programs and data. The first audio storage unit 12 can be configured, for example, with a semiconductor memory or a magnetic memory. The first audio storage unit 12 may store, for example, a program for operating the first audio device 10.

The first CEC control unit 13 controls the transmission and reception of CEC commands. The first CEC control unit 13 also executes various processes based on the received CEC commands. In this embodiment, the first CEC control unit 13 functions as a command control unit in the first audio device 10 of the present disclosure. Specific examples of the CEC commands transmitted and received by the first CEC control unit 13 and the processes it executes will be described later.

The first connection control unit 14 controls the audio connection with the television 30, which is a sound output control device. Specifically, when an audio connection between the television 30 and the first audio device 10 is established, the first connection control unit 14 releases the audio connection with the television 30, which is a sound output control device, based on the first CEC control unit 13 receiving a change command instructing a change of the audio device to which the audio connection is established. Also, when an audio connection between the television 30 and the first audio device 10 is not established, the first connection control unit 14 executes a process for establishing an audio connection with the television 30, which is a sound output control device, based on the first CEC control unit 13 receiving a release command from the audio device with which the audio connection with the television 30, which is a sound output control device, is established, notifying that the audio connection has been released. In this embodiment, the first connection control unit 14 functions as a connection control unit in the first audio device 10 of the present disclosure.

The first signal processing unit 15 extracts an audio signal from the signal input from the first HDMI cable 41 connected to the television 30, performs a predetermined signal processing, and outputs the signal to the first speaker 16. The predetermined signal processing is a known signal processing, and includes, for example, equalization processing, D/A conversion processing, and signal amplification processing.

The first speaker 16 outputs sound based on the audio signal processed by the first signal processing unit 15. The first speaker 16 can be configured using any known speaker.

The first power supply detection unit 17 detects when the power supply is on. The first power supply detection unit 17 can be configured, for example, with a known detection circuit capable of detecting when the power supply is on.

The first signal receiving unit 18 receives a signal transmitted from a remote controller (hereinafter also referred to as a "remote control") for remotely operating the first audio device 10. Specifically, when a user operates the remote control, an operation signal corresponding to the operation content is transmitted from the remote control by infrared rays. The first signal receiving unit 18 receives the operation signal transmitted by infrared rays. For example, a user operates the remote control when switching the power of the first audio device 10 between a standby state and an on state. The remote control transmits a signal corresponding to these operations. The first signal receiving unit 18 receives the signal transmitted from the remote control. The first audio control unit 11 executes processing corresponding to the content of the signal received by the first signal receiving unit 18.

Although the remote control has been described as transmitting an operation signal by infrared rays, the method of transmitting the operation signal does not necessarily have to be infrared. The remote control may transmit the operation signal by another method. The first signal receiving unit 18 receives the operation signal by a method corresponding to the method of transmitting the operation signal of the remote control.

The first audio control unit 11 may have some or all of the functions of the first CEC control unit 13, the first connection control unit 14, and the first signal processing unit 15 described above.

As shown in FIG. 2, the second audio device 20 includes, as functional units, a second audio control unit 21, a second audio memory unit 22, a second CEC control unit 23, a second connection control unit 24, a second signal processing unit 25, a second speaker 26, a second power supply detection unit 27, and a second signal receiving unit 28.

The second audio control unit 21 controls and manages the entire second audio device 20, including each functional unit of the second audio device 20. The second audio control unit 21 includes at least one processor. The second audio control unit 21 is configured with a processor such as a CPU that executes a program that defines a control procedure, or a dedicated processor specialized for processing each function.

The second audio storage unit 22 is a storage medium capable of storing programs and data. The second audio storage unit 22 can be configured, for example, with a semiconductor memory or a magnetic memory. The second audio storage unit 22 may store, for example, a program for operating the second audio device 20.

The second CEC control unit 23 controls the transmission and reception of CEC commands. The second CEC control unit 23 also executes various processes based on the received CEC commands. In this embodiment, the second CEC control unit 23 functions as a command control unit in the second audio device 20 of the present disclosure. Specific examples of the CEC commands transmitted and received by the second CEC control unit 23 and the processes it executes will be described later.

The second connection control unit 24 controls the audio connection with the television 30, which is a sound output control device. The second connection control unit 24 is configured similarly to the first connection control unit 14. That is, the second connection control unit 24 releases the audio connection with the television 30, which is a sound output control device, based on the second CEC control unit 23 receiving a change command. Furthermore, the second connection control unit 24 executes processing to establish an audio connection with the television 30, which is a sound output control device, based on the second CEC control unit 23 receiving a release command. In this embodiment, the second connection control unit 24 functions as a connection control unit in the second audio device 20 of the present disclosure.

The second signal processing unit 25 extracts an audio signal from the signal input from the second HDMI cable 42 connected to the television 30, performs a predetermined signal processing, and outputs the signal to the second speaker 26. The predetermined signal processing is a known signal processing, and includes, for example, equalization processing, D/A conversion processing, and signal amplification processing.

The second speaker 26 outputs sound based on the audio signal processed by the second signal processing unit 25. The second speaker 26 can be configured using any known speaker.

The second power supply detection unit 27 detects when the power supply is on. The second power supply detection unit 27 can be configured, for example, with a known detection circuit capable of detecting when the power supply is on. The second power supply detection unit 27 functions as a power supply detection unit in the second audio device 20 of the present disclosure.

The second signal receiving unit 28 receives a signal transmitted from a remote control for remotely operating the second audio device 20. Specifically, when a user operates the remote control, an operation signal corresponding to the operation content is transmitted from the remote control by infrared rays. The second signal receiving unit 28 receives the operation signal by infrared rays. For example, the user operates the remote control when switching the power of the second audio device 20 between a standby state and an on state. The remote control transmits a signal corresponding to these operations. The second signal receiving unit 28 receives the signal transmitted from the remote control. The second audio control unit 21 executes processing corresponding to the content of the signal received by the second signal receiving unit 28. Note that the remote control may transmit an operation signal by a method other than infrared rays. The second signal receiving unit 28 receives the operation signal by a method corresponding to the transmission method of the operation signal of the remote control.

The second audio control unit 21 may have some or all of the functions of the second CEC control unit 23, the second connection control unit 24, and the second signal processing unit 25 described above.

When the second audio device 20 is a neck speaker, the second audio device 20 is not actually expressed as one functional block as shown in FIG. 2, but is composed of a speaker body 20a and a transmitter 20b as shown in FIG. 1, for example. The speaker body 20a and the transmitter 20b are connected by wireless communication according to any standard such as Bluetooth (registered trademark). The transmitter is connected to the television 30 by a second HDMI cable 42. When an audio connection with the television 30 is established, the transmitter 20b receives an audio signal received from the television 30, and outputs sound from the speaker body 20a worn by the user by wireless communication based on the audio signal. Therefore, when the second audio device 20 is a neck speaker, each functional unit of the second audio device 20 described with reference to FIG. 2 or the function of each functional unit is distributed and installed in the speaker body 20a and the transmitter 20b.

As shown in FIG. 2, the television 30 includes, as functional units, a television control unit 31, a television memory unit 32, a remote control signal receiving unit 33, a television CEC control unit 34, a display unit 35, a television speaker 36, a tuner 37, a decoder 38, and a switching control unit 39.

The television control unit 31 controls and manages the entire television 30, including each functional unit of the television 30. The television control unit 31 includes at least one processor. The television control unit 31 is configured with a processor such as a CPU that executes a program that defines a control procedure, or a dedicated processor specialized for processing each function. For example, the television control unit 31 transmits an audio signal to be output to an audio device among multiple audio devices (i.e., the first audio device 10 and the second audio device 20) that has established an audio connection with the television 30, which is a sound output control device. In this embodiment, the television control unit 31 functions as a control unit in the television 30, which is a sound output control device of the present disclosure.

The television storage unit 32 is a storage medium capable of storing programs and data. The television storage unit 32 can be configured, for example, with a semiconductor memory or a magnetic memory. The television storage unit 32 may store, for example, programs for operating the television 30.

The remote control signal receiving unit 33 receives a signal transmitted from a remote control for remotely controlling the television 30. Specifically, when a user operates the remote control, an operation signal corresponding to the operation is transmitted from the remote control by infrared rays. The remote control signal receiving unit 33 receives the operation signal transmitted by infrared rays. For example, a user operates the remote control when selecting a channel of a broadcast program to be displayed on the television 30, changing the output volume, or making some other setting for the television 30. The remote control transmits a signal corresponding to these operations. The remote control signal receiving unit 33 receives a signal transmitted from the remote control. The television control unit 31 executes processing corresponding to the content of the signal received by the remote control signal receiving unit 33. The remote control may transmit an operation signal by a method other than infrared rays. The remote control signal receiving unit 33 receives the operation signal by a method corresponding to the transmission method of the operation signal of the remote control.

The TV CEC control unit 34 controls the sending and receiving of CEC commands. The TV CEC control unit 34 also executes various processes based on the received CEC commands.

The display unit 35 is a device that displays images. The display unit 35 may be configured with a well-known display such as a liquid crystal display (LCD), an organic electro-luminescence display (OELD), or an inorganic electro-luminescence display (IELD). For example, images of broadcast programs and a setting screen for the television 30 are displayed on the display unit 35.

The television speaker 36 is a speaker built into the television 30. The television speaker 36 outputs sound under the control of the television control unit 31 when no audio device is connected to the television 30, and when an audio device is connected to the television 30 but an audio connection has not been established.

Tuner 37 receives broadcast programs broadcast by terrestrial digital broadcasting and broadcast programs broadcast by satellite broadcasting. In addition to these broadcast programs, tuner 37 may also receive data broadcasts such as superimposed text and subtitles that are displayed superimposed on the broadcast programs, such as emergency earthquake alerts.

The decoder 38 decodes the video content of the broadcast program received by the tuner 37 into a video signal and an audio signal. The decoder 38 includes, for example, an RF unit that converts the received signal indicating the broadcast program received by the tuner 37 into an analog baseband signal, an ADC unit that converts the analog baseband signal into a digital baseband signal, a demodulation unit that demodulates the digital baseband signal into an MPEG2 stream, and a decoding unit that decodes the MPEG2 stream into a video signal and an audio signal.

The switching control unit 39 executes control for establishing an audio connection with an audio device. Specifically, the switching control unit 39 has a plurality of HDMI terminals capable of inputting and outputting video signals and audio signals. In the example shown in FIG. 2, the switching control unit 39 has two HDMI terminals. The switching control unit 39 establishes an audio connection with an audio device by selectively using an ARC (Audio Return Channel) function. In this embodiment, the switching control unit 39 selectively connects one of the plurality of HDMI terminals so that video signals and audio signals can be transmitted, thereby establishing an audio connection with an audio device connected to the selectively connected HDMI terminal.

The switching control unit 39 selectively uses the ARC function for an audio device that has acquired target device identification information among multiple audio devices, thereby establishing an audio connection with the audio device. Here, the target device identification information is information that identifies the audio device as a target device of sound output control by the television 30, which is a sound output control device. Specifically, the target device identification information is, for example, a logical address that can be acquired by the audio device by sending a polling message, and is a logical address (Audio System) that indicates that the audio device is a device that operates as a target of sound output control by the television 30. Only one audio device in an audio system can acquire the target device identification information.

Next, an example of processing executed by the sound output system 1 will be described. Figures 3 to 7 are sequence diagrams showing an example of processing by the sound output system 1. Figures 3 to 7 show a series of processing procedures executed by the sound output system 1. In other words, Figures 3 to 7 taken together show the entire processing executed by the sound output system 1.

At the start of the sequence shown in FIG. 3, the first audio device 10 and the second audio device 20 are in a state of being HDMI-connected to the television 30. Also, at the start of the sequence shown in FIG. 3, the first audio device 10 is in a state of having acquired target device identification information.

At the start of the sequence shown in FIG. 3, the first audio device 10, the second audio device 20, and the television 30 are in a standby state. Here, the standby state is a waiting state in which output of images and sounds cannot be performed, but transmission and reception of signals and commands can be performed.

In the sequence shown in FIG. 3, first, the user wishes to watch the television 30 and performs an operation on the remote control for the television 30 to turn on the power of the television 30 (step S11).

When the user performs an operation to turn on the power of the television 30, the remote control transmits a power-on signal to the television 30 based on the operation, instructing the television 30 to turn on the power (step S12).

When the television 30 receives the power-on signal via the remote control signal receiver 33, the television control unit 31 controls the television 30 based on the power-on signal to turn the power on (step S13).

When the television 30 is turned on, the CEC control unit 34 transmits a power-on command to the audio device with which an audio connection has been established. Here, since an audio connection has been established between the television 30 and the first audio device 10, the CEC control unit 34 transmits a power-on command to the first audio device 10 (step S14). The power-on command is a command that instructs turning on the power. The power-on command may include information that can uniquely identify the device to be turned on. For example, here, the power-on command may include information that can uniquely identify the first audio device 10. In this case, the power-on command is a command that instructs turning on the power of the first audio device 10.

When the first CEC control unit receives the power-on command, the first audio device 10 is turned on by the control of the first audio control unit 11 based on the power-on command (step S15).

When the first audio device 10 detects that the HDMI terminal has been connected, it transmits an inquiry command from the first CEC control unit 13 (step S16). The inquiry command is a command for inquiring whether or not there is an audio device with which an audio connection has been established. Specifically, for example, the first audio device 10 can inquire whether or not it is possible to obtain target device identification information by using the inquiry command. In step S16, the first audio device 10 transmits the inquiry command to inquire whether or not another audio device has already obtained target device identification information. The inquiry command includes information that can uniquely identify the device that transmitted the inquiry command. Specifically, the information that can uniquely identify the device is, for example, a physical address.

If another audio device has already acquired the target device identification information, when the other audio device that has acquired the target device identification information receives the inquiry command, it sends a reply command in response to the inquiry command indicating that there is an audio device with which an audio connection has been established. When the audio device that sent the inquiry command receives the reply command, it can determine that it cannot acquire the target device identification information because the other audio device has already acquired the target device identification information. In this case, since the audio device that sent the inquiry command cannot acquire the target device identification information, it acquires a logical address indicating that it does not have a specific role in the CEC network. A logical address indicating that it does not have a specific role is, for example, an address indicating "unregistered."

On the other hand, if there is no audio device that has acquired the target device identification information, no answer command will be sent from any audio device. In other words, if the audio device that sent the inquiry command does not receive a reply command, it can determine that there is no audio device that has acquired the target device identification information. In this case, the audio device that sent the inquiry command can acquire the target device identification information.

In the example shown in FIG. 3, other than the first audio device 10, no other audio devices are HDMI-connected to the television 30. Therefore, no audio device has acquired the target device identification information, and therefore no reply command is sent in response to the inquiry command sent by the first audio device 10.

In the flow of FIG. 3, since it is assumed that the first audio device 10 has acquired the target device identification information, it is not necessarily necessary to inquire whether the target device identification information can be acquired by sending an inquiry command in step S16. If the first audio device 10 that has acquired the target device identification information leaves the CEC network while it has acquired the target device identification information, another audio device may acquire the target device identification information while the first audio device 10 is away. In this state, when the first audio device 10 is reconnected to the CEC network, the CEC network will have two audio devices that have acquired the target device identification information. Therefore, even if the first audio device 10 has already acquired the target device identification information, it is preferable that the first audio device 10 transmits an inquiry command as described in step S16 when the power is turned on. This makes it possible to prevent the existence of multiple audio devices that have acquired the target device identification information. In this way, it is possible to prevent inconsistencies that may occur in the CEC network in advance.

Since the first audio device 10 has not received the answer command, it acquires the target device identification information (step S17). In this case, since the first audio device 10 has acquired the target device identification information at the start of the flow in FIG. 3, the first audio device 10 maintains the state of having acquired the target device identification information in step S17.

The first audio device 10 also transmits a notification command from the first CEC control unit 13 (step S18). The notification command is a message notifying that the audio device 10 itself can operate as a target device of the sound output control. The notification command may include information that can uniquely identify the audio device that transmitted the notification command (i.e., the first audio device 10 in this case). When the established state of the audio connection has changed, the notification command is transmitted from the audio device whose established state of the audio connection has changed. The established state of the audio connection is a state regarding whether or not the audio connection is established. The established state of the audio connection changes when the target device identification information is acquired (step S18 in FIG. 3, step S43 in FIG. 5 to be described later, and step S72 in FIG. 6 to be described later, etc.) and when the target device identification information is released (step S38 in FIG. 4 to be described later, and step S68 in FIG. 6 to be described later, etc.). The notification command may be transmitted from the audio device that is connected to the television 30 in a communicable manner when the audio device is connected to the television 30 as the sound output control device in a communicable manner.

By receiving the notification command sent in step S18, the television 30 can identify the audio device that sent the notification command and recognize that the audio device that sent the notification command is capable of operating as a target device for sound output control.

When the television 30 receives the notification command, for example, it stores the audio device that sent the notification command in the television storage unit 32 as an audio device that can operate as a target device for sound output control. The television 30 can present the user with a list of audio devices that can output sound by displaying, for example, on the display unit 35, a list of audio devices that can operate as target devices for sound output control that are stored in the television storage unit 32. The user can select an audio device that will output sound from the audio devices displayed in the list, or switch between audio devices that will output sound, for example, by operating a remote control.

In step S18, the first audio device 10 may transmit information about the first audio device 10 in the notification command. The information about the first audio device 10 may include, for example, the model name of the first audio device 10 and the physical address to which the first audio device 10 is assigned. This allows the television 30 to obtain information about the first audio device 10 when it receives the notification command.

However, the timing at which the information about the first audio device 10 is transmitted is not limited to this. The information about the first audio device 10 may be transmitted separately at a timing different from the timing at which the notification command is transmitted. For example, the information about the first audio device 10 may be transmitted when the television 30 and the first audio device 10 are HDMI-connected, when the first audio device 10 is powered on (step S15), etc.

The television 30 establishes an audio connection with the audio device (here, the first audio device 10) from which the target device identification information has been obtained (step S19). Specifically, the television 30 establishes an audio connection with the first audio device 10 by the switching control unit 39 selectively using the ARC function for the first audio device 10 based on the control of the television control unit 31. More specifically, the switching control unit 39 establishes an audio connection with the first audio device 10 by selectively connecting, among multiple HDMI terminals, the HDMI terminal to which the first audio device 10 is connected so that video signals and audio signals can be transmitted.

With an audio connection thus established between the television 30 and the first audio device 10, the television 30 transmits an audio signal to the first audio device 10 (step S20).

When the first audio device 10 receives the audio signal transmitted from the television 30, it outputs sound corresponding to the audio signal (step S21). In this way, after the television 30 is turned on by the user's operation, an audio connection between the television 30 and the first audio device 10 is established, and sound is output from the first audio device 10. In this way, the user only needs to perform an operation to turn on the television 30, and the first audio device 10, which has acquired the target device identification information, will be switched from a standby state to an on state, and sound will be output from the first audio device 10,

The sequence shown in FIG. 4 is executed following the sequence shown in FIG. 3. That is, at the start of the sequence shown in FIG. 4, the first audio device 10 has established an audio connection with the television 30, which is a sound output control device, and the second audio device 20 has not established an audio connection with the television 30, which is a sound output control device. FIG. 4 shows a part of the audio connection switching method executed by the sound output system 1.

Assuming that, as described in FIG. 3, while sound is being output from the first audio device 10, the user wishes to output sound from the second audio device 20. In this case, the user performs an operation on the remote control of the second audio device 20 to turn on the power of the second audio device 20 (step S31).

When the user performs an operation to turn on the power of the second audio device 20, the remote control transmits a power-on signal to the second audio device 20 based on the operation, instructing the second audio device 20 to be powered on (step S32).

When the second signal receiving unit 28 receives the power-on signal, the second audio device 20 is turned on by the control of the second audio control unit 21 based on the power-on signal (step S33).

When the second power supply detection unit 27 detects that the power supply of the second audio device 20 has been turned on, the second audio device 20 transmits a query command from the second CEC control unit 23 (step S34). The query command transmitted here is the same as the query command described in step S16.

Here, the first audio device 10 has already acquired the target device identification information through the sequence described in FIG. 3. In other words, an audio device with which an audio connection has been established already exists. Therefore, when the first audio device 10 receives an inquiry command from the second audio device 20, it transmits a response command from the first CEC control unit 13 to the second audio device 20 (step S35).

Based on receiving the answer command in step S35, the second audio device 20 transmits a change command to instruct a change of the audio device to which the audio connection is established (step S36). The change command is a command to instruct a change of the audio device to which the audio connection is to be established. The change command may include information that specifies the audio device to which the audio connection is to be switched (here, the second audio device 20). The change command may also include an instruction to put the power supply into standby state after releasing the target device identification information.

The audio device that is audio-connected releases the target device identification information based on receiving the change command, and acquires an address indicating "unregistered". The audio device that is audio-connected releases the audio connection with the television 30 by releasing the target device identification information. Here, the first audio device 10 receives the change command in the first CEC control unit 13. The first audio device 10 releases the audio connection with the television 30 by releasing the target device identification information based on receiving the change command (step S37). After releasing the target device identification information, the first audio device 10 also acquires an address indicating "unregistered" (step S37).

Then, the first audio device 10 that has released the target device identification information transmits a notification command (step S38). As a result, the first audio device 10 is recognized by the television 30 as an audio device that can operate as a target device for sound output control, even after the audio connection has been released.

The first audio device 10 transmits a release command based on the release of the audio connection (step S39). The release command is a command that notifies the audio device that was audio-connected that it has released the audio connection. The release command allows the television 30 and the second audio device 20 to recognize that the audio connection has been released.

After transmitting the release command in step S39, the first audio device 10 puts the power of the first audio device 10 into standby mode. That is, the first audio device 10 puts the power of the first audio device 10 into standby mode from an on state based on the instruction to put the power into standby mode contained in the change command (step S40). In this way, the first audio device 10 that has released the target device identification information automatically puts the power into standby mode without receiving a separate operation input from the user, for example. That is, an audio device that will no longer be used due to a change in the audio device connected to the audio device will automatically put the power into standby mode. This increases convenience because the user does not need to perform a separate operation.

The sequence shown in FIG. 5 is executed following the sequence shown in FIG. 4. FIG. 5 shows a part of the audio connection switching method executed by the sound output system 1.

Based on receiving the release command transmitted in step S39 of FIG. 4, the second audio device 20 executes processing to establish an audio connection with the television 30, which is a sound output control device. Here, as shown in step S42, the second audio device 20 executes processing to establish an audio connection with the television 30 by acquiring target device identification information. In this embodiment, before acquiring the target device identification information, the second audio device 20 inquires in step S41 whether there is an audio device with which an audio connection has been established.

That is, when the second CEC control unit 23 receives the release command, the second audio device 20 transmits an inquiry command (step S41). The inquiry command transmitted here is the same as the inquiry command described in step S16. That is, here, the second audio device 20 inquires as to whether another audio device has already acquired the target device identification information.

At this time, since the first audio device 10 has already released the audio connection, there is no audio device that has acquired the target device identification information, so no response command is sent in response to the inquiry command sent by the second audio device 20 in step S41.

Since the second audio device 20 has not received the response command, it acquires the target device identification information (step S42).

The second audio device 20 also transmits a notification command from the second CEC control unit 23 (step S43). The notification command transmitted here is the same as the notification command described in step S18. By receiving the notification command transmitted in step S43, the television 30 can identify the second audio device 20 that transmitted the notification command, and can recognize that the second audio device 20 is capable of operating as a target device for sound output control.

The television 30 causes the television control unit 31 to establish an audio connection with the second audio device 20 (step S44) based on the second audio device 20 having executed a process for establishing an audio connection with the television 30 as a result of the second audio device 20 being turned on (in this embodiment, acquisition of target device identification information in step S42). Specifically, the television 30 establishes an audio connection with the second audio device 20 by the switching control unit 39 selectively using the ARC function for the second audio device 20 based on the control of the television control unit 31. More specifically, the switching control unit 39 establishes an audio connection with the second audio device 20 by selectively connecting, among a plurality of HDMI terminals, the HDMI terminal to which the second audio device 20 is connected so that video signals and audio signals can be transmitted.

With an audio connection thus established between the television 30 and the second audio device 20, the television 30 transmits an audio signal to the second audio device 20 (step S45).

When the second audio device 20 receives the audio signal transmitted from the television 30, it outputs sound corresponding to the audio signal (step S46). In this way, when the power of the second audio device 20 is turned on by the user's operation, the audio device audio-connected to the television 30 is automatically switched to the second audio device 20 whose power is turned on, and sound is output from the second audio device 20.

In this way, the user only needs to perform an operation to turn on the second audio device 20, and the audio device audio-connected to the television 30 is automatically switched to the second audio device 20. In other words, when the user performs an operation to turn on the power of the second audio device 20, it is presumed that the user intends to output sound from the second audio device 20. In such a case, the audio device audio-connected to the television 30 is automatically switched to the second audio device 20, thereby switching the sound output destination in line with the user's intention. Therefore, the user does not need to perform a separate operation to switch the sound output destination. This allows the sound output system 1 to easily switch the sound output destination without requiring a separate operation by the user.

Next, assume that the user attempts to stop the sound output from the second audio device 20 by performing an operation on the remote control of the second audio device 20 to put the power of the second audio device 20 into standby mode (step S47).

When the user performs an operation to put the power of the second audio device 20 into standby, the remote control transmits a power standby signal to the second audio device 20 based on the operation, instructing the second audio device 20 to put the power of the second audio device 20 into standby (step S48).

When the second signal receiving unit 28 receives the power standby signal, the second audio device 20 stops the audio connection with the television 30 (step S49). For example, the second audio device 20 transmits a command to the television 30 to instruct it to stop the audio connection, and the television 30 stops using the ARC function based on the command, thereby stopping the audio connection between the television 30 and the second audio device 20. Stopping the use of the ARC function can be executed, for example, by the switching control unit 39 disconnecting the connection to the HDMI terminal to which the second audio device 20 is connected.

When the audio connection between the second audio device 20 and the television 30 is stopped, the second audio device 20 goes into a power standby state under the control of the second audio control unit 21 based on the power standby signal (step S50).

Furthermore, when the audio connection between the second audio device 20 and the television 30 is stopped, the television 30 outputs sound from the television speakers 36 since it is no longer audio connected to any audio device (step S51).

The sequence shown in FIG. 6 is executed following the sequence shown in FIG. 5. That is, at the start of the sequence shown in FIG. 6, the television 30 is not audio-connected to any audio device. FIG. 6 is an example of a process that is executed when a user wishes to output sound from the first audio device 10.

First, the user operates the remote control of the first audio device 10 to turn on the power of the first audio device 10 (step S61).

When the user performs an operation to turn on the power of the first audio device 10, the remote control transmits a power-on signal to the first audio device 10 based on the operation, instructing the first audio device 10 to be turned on (step S62).

When the first signal receiving unit 18 receives the power-on signal, the first audio device 10 is turned on by the control of the first audio control unit 11 based on the power-on signal (step S63).

When the first power supply detection unit 17 detects that the power supply of the first audio device 10 has been turned on, the first audio device 10 transmits an inquiry command from the first CEC control unit 13 (step S64). The inquiry command transmitted here is the same as the inquiry command described in step S16. In other words, here, the first audio device 10 inquires as to whether or not another audio device has already acquired the target device identification information.

Here, the audio connection between the second audio device 20 and the television 30 has been stopped in step S49 of FIG. 5, but the second audio device 20 still has acquired the target device identification information. Therefore, when the second audio device 20 receives an inquiry command from the first audio device 10, it transmits a response command from the second CEC control unit 23 to the first audio device 10 (step S65).

Based on receiving the answer command in step S65, the first audio device 10 transmits a change command to instruct a change of the audio device to which the audio connection is established (step S66). The change command transmitted here is the same as the change command described in step S36.

Based on receiving the change command, the second audio device 20 releases the target device identification information and obtains an address indicating "unregistered" (step S67).

Then, the second audio device 20, which has released the target device identification information, transmits a notification command (step S68). As a result, the second audio device 20 is recognized by the television 30 as an audio device that can operate as a target device for sound output control, even after the audio connection has been released.

The second audio device 20 transmits a release command based on the release of the audio connection (step S69). The release command transmitted here is the same as the release command described in step S39. The release command enables the television 30 and the first audio device 10 to recognize that the audio connection has been released.

Based on receiving the release command, the first audio device 10 executes processing to establish an audio connection with the television 30, which is a sound output control device. Here, as shown in step S71, the first audio device 10 executes processing to establish an audio connection with the television 30 by acquiring target device identification information. In this embodiment, before acquiring the target device identification information, the first audio device 10 inquires in step S70 whether there is an audio device with which an audio connection has been established.

That is, when the first CEC control unit 13 receives the release command, the first audio device 10 transmits an inquiry command (step S70). The inquiry command transmitted here is the same as the inquiry command described in step S16. That is, here, the first audio device 10 inquires as to whether another audio device has already acquired the target device identification information.

At this time, since the second audio device 20 has already released the target device identification information, there is no audio device that has acquired the target device identification information, and therefore no response command is sent in response to the inquiry command sent by the first audio device 10 in step S70.

Since the first audio device 10 has not received a response command, it acquires the target device identification information (step S71).

The first audio device 10 also transmits a notification command from the first CEC control unit 13 (step S72). The notification command transmitted here is the same as the notification command described in step S18. By receiving the notification command transmitted in step S72, the television 30 can identify the first audio device 10 that transmitted the notification command, and can recognize that the first audio device 10 is capable of operating as a target device for sound output control.

The television 30 establishes an audio connection with the first audio device 10 from which the target device identification information has been obtained (step S73). Specifically, the television 30 establishes an audio connection with the first audio device 10 by the switching control unit 39 selectively using the ARC function for the first audio device 10 based on the control of the television control unit 31. More specifically, the switching control unit 39 establishes an audio connection with the first audio device 10 by selectively connecting, among multiple HDMI terminals, the HDMI terminal to which the first audio device 10 is connected so that video signals and audio signals can be transmitted.

With an audio connection thus established between the television 30 and the first audio device 10, the television 30 transmits an audio signal to the first audio device 10 (step S74).

When the first audio device 10 receives the audio signal transmitted from the television 30, it outputs sound corresponding to the audio signal (step S75). In this way, when the first audio device 10 is turned on by a user operation, the audio device audio-connected to the television 30 is automatically switched to the first audio device 10 that has been turned on, and sound is output from the first audio device 10. As a result, for the same reason as described with reference to FIG. 5, the sound output system 1 can easily switch the sound output destination without requiring a separate operation by the user.

The sequence shown in FIG. 7 is executed following the sequence shown in FIG. 6. That is, at the start of the sequence shown in FIG. 7, an audio connection is established between the television 30 and the first audio device 10. FIG. 7 shows an example of a process that is executed when the user ends watching the television 30.

First, the user operates the remote control of the television 30 to put the power of the television 30 into standby mode (step S81).

When the user performs an operation to put the power of the television 30 into standby, the remote control transmits a power standby signal to the television 30 based on the operation, instructing the television 30 to put the power of the television 30 into standby (step S82).

When the TV 30 receives the power standby signal at the remote control signal receiving unit 33, the TV CEC control unit 34 transmits a power standby command to the audio device connected to the TV 30 to instruct it to put the power into standby mode (step S83). Here, the TV 30 transmits the power standby command to the first audio device 10 and the second audio device 20.

Then, the television 30 goes into power standby state under the control of the television control unit 31 based on the power standby signal (step S84). The first audio device 10 and the second audio device 20 go into power standby state under the control of the first audio control unit 11 and the second audio control unit 21 based on the power standby command received from the television 30 (step S84). Note that here, the second audio device 20 is already in power standby state, so the power standby state is maintained.

In this way, when a user operates to put the power of the television 30 into standby, the television 30 goes into standby and the first audio device 10 and the second audio device 20 connected to the television 30 also go into standby. This eliminates the need for the user to perform a separate operation to put the power of the first audio device 10 and the second audio device 20 into standby.

According to the sound output system 1 of the present embodiment, the second audio device 20 transmits an inquiry command when it detects that the power has been turned on, and the first audio device 10 transmits an answer command to the second audio device 20 in response to the inquiry command. The second audio device 20 transmits a change command based on receiving the answer command, and the first audio device 10 releases the audio connection with the television 30 based on receiving the change command, and transmits a release command to the second audio device 20 based on releasing the audio connection. The second audio device 20 executes a process for establishing an audio connection with the television 30 based on receiving the release command. In this way, the television 30, which is a sound output control device, can switch the sound output destination between multiple external audio devices connected to the television 30, which is also a sound output control device. In particular, in the sound output system 1, the second audio device 20 automatically switches the sound output destination by detecting that the power has been turned on, so that the sound output destination can be easily switched without requiring a separate operation by the user.

In this embodiment, the second audio device 20 transmits the notification command after acquiring the target device identification information (step S43 in FIG. 5) and after releasing the target device identification information (step S68 in FIG. 6). The second audio device 20 may transmit the notification command when it is communicatively connected to the television 30, which is a sound output control device. When it is communicatively connected to the television 30, it means that the HDMI terminal of the second audio device 20 and the HDMI terminal of the television 30 are connected by an HDMI cable. The second audio device 20 may be configured to transmit the notification command at least either after it is communicatively connected to the television 30 and after it acquires the target device identification information.

In the above embodiment, the change command has been described as including an instruction to put the power supply into standby mode after releasing the target device identification information. However, the change command does not necessarily have to include an instruction to put the power supply into standby mode after releasing the target device identification information. For example, an instruction to put the power supply into standby mode after releasing the target device identification information may be sent as a command (power supply standby command) separate from the change command.

Figure 8 is a sequence diagram showing a modified example of the sequence shown in Figure 5. Specifically, Figure 8 is a sequence diagram showing an example in which the change command does not include an instruction to put the power supply into standby state after the target device identification information is released, and a separate power supply standby command is sent. Regarding Figure 8, the description of the processes common to Figure 5 will be omitted as appropriate, and the differences will be mainly described.

When the user operates the remote control of the second audio device 20 to power on the second audio device 20 (step S31), the remote control transmits a power-on signal to the second audio device 20 (step S32). The second audio device 20 turns on based on the power-on signal (step S33). It transmits an inquiry command (step S34). The first audio device 10 transmits a response command in response to the inquiry command received from the second audio device 20 (step S35).

The second audio device 20 transmits a change command based on the response command received in step S35 (step S85). The change command transmitted in step S85 is a command to instruct a change of the audio device to which the audio connection is established. The change command transmitted in step S85 may include information that identifies the audio device to which the audio connection is to be switched (here, the second audio device 20). The change command transmitted in step S85 does not include an instruction to put the power into standby state after releasing the target device identification information.

Based on receiving the change command, the first audio device 10 releases the target device identification information and obtains an address indicating "unregistered" (step S37). The first audio device 10 then transmits a notification command (step S38) and a release command (step S39).

In the modified example shown in FIG. 8, after transmitting the change command in step S85, the second audio device 20 transmits a power standby command to the first audio device 10 (step S86). The power standby command is a command to instruct the power to be placed in a standby state.

When the first audio device 10 receives the power standby command transmitted in step S86, it places the power in standby state (step S40). The process executed after step S40 may be the same as that shown in FIG. 6.

In this way, even if a power standby command separate from the change command is sent, it is possible to execute processing equivalent to the sequence described in the first embodiment.

Also, even if the change command does not include an instruction to put the power supply in standby state after the target device identification information is released, a power supply standby command does not necessarily have to be sent. In this case, for example, when the user performs an operation on the remote control of the first audio device 10 to put the power supply of the first audio device 10 in standby, the first audio device 10 may put the power supply in standby state. That is, when the user performs an operation on the remote control of the first audio device 10 to put the power supply of the first audio device 10 in standby, the remote control transmits a power supply standby signal instructing the power supply of the first audio device 10 to be in standby. The first audio device 10 may put the power supply in standby state based on receiving the power supply standby signal. In this case, the power supply of the first audio device 10 is put in standby state by the user performing an operation to put the power supply in standby state, so that the power supply of the first audio device 10 can be put in standby state at the timing desired by the user.

[Second embodiment]
FIG. 9 is a functional block diagram showing an example of the configuration of the sound output system 2 according to the second embodiment. As shown in FIG. 9, the sound output system 2 according to the second embodiment includes a television 130 which is a sound output control device, and a plurality of audio devices. In the example shown in FIG. 9, the sound output system 2 includes two audio devices, a first audio device 110 and a second audio device 120, as the plurality of audio devices. However, the number of audio devices included in the sound output system 2 is not limited to two. The sound output system 2 may include three or more audio devices. Hereinafter, for the sound output system 2 according to the second embodiment, the same reference numerals are given to components that are the same or equivalent to those in the first embodiment, and descriptions of the same or equivalent contents as those in the first embodiment are omitted as appropriate, and differences are mainly described.

The configuration of the first audio device 110 according to the second embodiment is the same as that of the first audio device 10 according to the first embodiment, except that it has an optical digital connection unit 19 as a functional block. The optical digital connection unit 19 is an interface for establishing an optical digital connection with an external device using an optical digital cable 43. The optical digital connection unit 19 is formed, for example, of an optical digital terminal. The other configurations and functions of the first audio device 110 are similar to those of the first audio device 10 described in the first embodiment, so detailed description will be omitted here.

The configuration and functions of the second audio device 120 according to the second embodiment are similar to those of the second audio device 20 according to the first embodiment, and therefore a detailed description thereof will be omitted here. However, in this embodiment, the change command transmitted by the second audio device 120 does not include an instruction to put the power supply into standby mode after releasing the target device identification information.

The configuration of the television 130 according to the second embodiment is the same as that of the television 30 according to the first embodiment, except that the television 130 has an optical digital connection unit 40 as a functional block. The optical digital connection unit 40 is an interface for establishing an optical digital connection with an external device using an optical digital cable 43. The optical digital connection unit 40 is formed, for example, of an optical digital terminal. The other configurations and functions of the television 130 are similar to those of the television 30 described in the first embodiment, so detailed description will be omitted here.

In this embodiment, an optical digital connection is established between the first audio device 110 and the television 130 via an optical digital cable 43. In this embodiment, the television 130, which is a sound output control device, outputs sound from the first audio device 110 that has an optical digital connection with the television 130 when the first audio device 110 has not established an audio connection with the television 130.

Next, an example of processing executed by the sound output system 2 according to the second embodiment will be described. Figs. 10 to 12 are sequence diagrams showing an example of processing by the sound output system 2. Figs. 10 to 12 show a series of processing procedures executed by the sound output system 2. In other words, Figs. 10 to 12 taken together show the entire processing executed by the sound output system 2.

In the sound output system 2 according to the second embodiment, an audio connection is established between the first audio device 110 and the television 130 by a process equivalent to the process described in FIG. 3 for the sound output system 1 according to the first embodiment, and sound is output from the first audio device 110.

The sequence shown in FIG. 10 is executed following the execution of a process equivalent to the sequence shown in FIG. 3. That is, at the start of the sequence shown in FIG. 10, the first audio device 10 has established an audio connection with the television 30, and the second audio device 20 has not established an audio connection with the television 30.

In the sequence shown in FIG. 10, when a user operates the remote control of the second audio device 120 to power on the second audio device 120 (step S101), the remote control transmits a power-on signal to the second audio device 120 (step S102). The second audio device 120 turns on based on the power-on signal (step S103). It transmits an inquiry command (step S104). The first audio device 110 transmits a response command in response to the inquiry command received from the second audio device 120 (step S105). The details of the processing in steps S101 to S105 are equivalent to the processing in steps S31 to S35 in FIG. 4, respectively.

The second audio device 120 transmits a change command based on the response command received in step S105 (step S106). The change command transmitted in step S106 is the same as the change command described in step S85 of FIG. 8. That is, the change command here is a command to instruct a change of the audio device to which the audio connection is established, and does not include an instruction to put the power into standby mode after releasing the target device identification information.

Based on receiving the change command, the first audio device 110 releases the target device identification information and obtains an address indicating "unregistered" (step S107). The first audio device 10 then transmits a notification command (step S108) and a release command (step S109). The details of the processes in steps S107 to S109 are equivalent to the processes in steps S37 to S39 in FIG. 4, respectively.

In this way, when the audio connection between the first audio device 110 and the television 130 is released, the television 130 becomes capable of transmitting an audio signal to the first audio device 110 via the optical digital cable 43 (step S110).

Based on the audio signal received at the optical digital connection unit 19, the first audio device 110 outputs sound corresponding to the audio signal (step S111). In this way, the first audio device 110 can continue to output sound based on the audio signal input via the optical digital cable 43 even after the audio connection with the television 130 is released.

The sequence shown in FIG. 11 is executed following the sequence shown in FIG. 10.

When the second audio device 120 receives the release command transmitted in step S109 in FIG. 10, it transmits an inquiry command (step S121). At this time, since the first audio device 110 has already released the audio connection, there is no audio device that has acquired the target device identification information, and therefore no reply command is transmitted in response to the inquiry command transmitted by the second audio device 120 in step S121. Since the second audio device 20 has not received the reply command, it acquires the target device identification information (step S122). In addition, the second audio device 120 transmits a notification command from the second CEC control unit 23 (step S123). Then, the television 130 establishes an audio connection with the second audio device 120 by the television control unit 31 (step S124). With the audio connection thus established between the television 130 and the second audio device 120, the television 130 transmits an audio signal to the second audio device 120 (step S125). The second audio device 120 outputs a sound corresponding to the received audio signal (step S126). The details of the processes in steps S121 to S126 are the same as those in steps S41 to S46 in FIG. 5, respectively.

Note that the content of the audio signal transmitted via the audio connection in step S125 of FIG. 11 is the same as the content of the audio signal transmitted via the optical digital connection in step S110 of FIG. 10. Therefore, in this embodiment, the sound output from the first audio device 110 in step S111 of FIG. 10 is the same as the sound output from the second audio device 120 in step S126 of FIG. 11. In other words, in this embodiment, the same sound is output from both the first audio device 110 and the second audio device 120. In this way, according to the sound output system 2 of the second embodiment, sound can be output simultaneously from multiple audio devices.

Next, assume that the user operates the remote control of second audio device 120 to put second audio device 120 into standby mode (step S127). Based on the user's operation, the remote control transmits a power standby signal to second audio device 120 (step S128). When second signal receiving unit 28 receives the power standby signal, second audio device 120 stops the audio connection with television 130 (step S129). Details of the processing from step S127 to step S129 are equivalent to the processing from step S47 to step S49 in FIG. 5, respectively.

When the audio connection between the second audio device 120 and the television 130 is terminated, the second audio device 120 transmits a standby notification command from the second CEC control unit 23 to the first audio device 110 to notify the first audio device 110 that the power supply of the second audio device 120 will be switched to standby mode (step S130). The standby notification command is transmitted when the audio device that has acquired the target device identification information (here, the second audio device 120) switches the power supply to standby mode.

After transmitting the standby notice command in step S130, the second audio device 120 is controlled by the second audio control unit 21 to switch to a standby state (step S131).

The sequence shown in FIG. 12 is executed following the sequence shown in FIG. 11. That is, at the start of the sequence shown in FIG. 12, the television 130 is not audio-connected to any audio device.

By receiving the standby notice command in step S130 of FIG. 11, the first audio device 110 can recognize that the audio device that sent the standby notice command (here, the second audio device 120) will put the power supply into standby state. In this case, the first audio device 110 sends an inquiry command from the first CEC control unit 13 (step S141). Here, since the second audio device 120 still has the target device identification information, when it receives the inquiry command from the first audio device 110, it sends an answer command from the second CEC control unit 23 to the first audio device 110 (step S142). The first audio device 110 sends a change command based on the reception of the answer command (step S143). The second audio device 120 releases the target device identification information based on the reception of the change command, and acquires an address indicating "unregistered" (step S144). Then, the second audio device 120 sends a notification command (step S145). Furthermore, the second audio device 120 transmits a release command based on the release of the audio connection (step S146). The details of the processes in steps S141 to S146 are equivalent to the processes in steps S64 to S69 in FIG. 6, respectively.

When the first audio device 110 receives the release command, it transmits an inquiry command (step S147). At this time, since the second audio device 120 has already released the target device identification information, there is no audio device that has acquired the target device identification information, and therefore no response command is transmitted to the inquiry command transmitted by the first audio device 110 in step S147. Since the first audio device 110 has not received the response command, it acquires the target device identification information (step S148). Then, the first audio device 110 transmits a notification command from the first CEC control unit 13 (step S149). The television 130 establishes an audio connection with the first audio device 110 (step S150). With the audio connection thus established between the television 130 and the first audio device 110, the television 130 transmits an audio signal to the first audio device 110 (step S151). The first audio device 110 outputs a sound corresponding to the received audio signal (step S152). The details of the processing in steps S147 to S152 are equivalent to the processing in steps S70 to S75 in FIG. 6, respectively.

According to the sound output system 2 of the second embodiment, the television 130, which is a sound output control device, can output sound from the first audio device 110 with which an optical digital connection has been established, even in a state in which an audio connection with the first audio device 110 has not been established. Therefore, the sound output system 2 can continue to output sound from the first audio device 110 even in a state in which an audio connection between the first audio device 110 and the television 130 has not been established.

Furthermore, according to the sound output system 2 of the second embodiment, when the power supply of the second audio device 120 is turned on, an audio connection is established between the second audio device 120 and the television 130, and sound can be output from the second audio device 120, and sound can also be output from the first audio device 110 using an optical digital connection. Furthermore, in the sound output system 2, when the power supply of the second audio device 120 is in a standby state, an audio connection between the first audio device 110 and the television 130 is automatically established without requiring a separate operation from the user. Then, the first audio device 110, whose audio connection with the television 130 has been established, can output sound using the audio connection. In this way, the sound output system 2 can appropriately change the established state of the audio connection between the first audio device 110 and the television 130 in response to switching between the power supply of the second audio device 120 being on and being in standby.

In the above first and second embodiments, an example has been described in which a sound output system establishes an audio connection between two audio devices. However, the present disclosure is also applicable to a sound output system having three or more audio devices.

In the above embodiment, an audio device that has established an audio connection with the television 30, which is a sound output control device, may be configured to be able to transmit to the television 30 the device name of the audio device to be displayed on the OSD (On-Screen Display) of the television 30. The television 30 stores the device name transmitted from the audio device, for example, in the television storage unit 32. For example, when the power of an audio device is switched from a standby state to an on state, the television 30 receives the device name from the audio device that has been switched on. The television 30 determines whether the device name received in this manner matches the device name of an audio device with which an audio connection was previously established. For example, the television 30 determines whether the received device name matches the device name stored in the television storage unit 32. If the received device name does not match the device name of an audio device with which an audio connection was previously established, the television 30 displays the received device name on the OSD.

In addition, in the above embodiment, the audio device may be configured to be able to transmit the device name of the audio device to the television 30 when the audio connection with the television 30 is released. In this case, the television 30 may display on the display unit 35 that the audio connection of the audio device with the received device name has been released. This allows the user who checks the display on the display unit 35 to recognize that the audio connection of the audio device with that device name has been released.

Although the present disclosure has been described based on the drawings and embodiments, it should be noted that a person skilled in the art would easily be able to make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present disclosure. For example, the functions included in each functional unit or step can be rearranged so as not to cause logical inconsistencies, and multiple functional units or steps can be combined into one or divided.

1, 2 Sound output system 10, 110 First audio device 11 First audio control unit 12 First audio storage unit 13 First CEC control unit 14 First connection control unit 15 First signal processing unit 16 First speaker 17 First power supply detection unit 18 First signal receiving unit 19, 40 Optical digital connection unit 20, 120 Second audio device 20a Speaker body 20b Transmitter 21 Second audio control unit 22 Second audio storage unit 23 Second CEC control unit 24 Second connection control unit 25 Second signal processing unit 26 Second speaker 27 Second power supply detection unit 28 Second signal receiving unit 30, 130 Television (sound output control device)
Reference Signs List 31 Television control unit 32 Television storage unit 33 Remote control signal receiving unit 34 Television CEC control unit 35 Display unit 36 Television speaker 37 Tuner 38 Decoder 39 Switching control unit 41 First HDMI cable 42 Second HDMI cable 43 Optical digital cable

Claims (10)

a sound output control device; and a plurality of audio devices including a first audio device and a second audio device communicatively connected to the sound output control device,
the sound output control device causes a sound to be output from an audio device that has established an audio connection with the sound output control device, among the plurality of audio devices;
1. A sound output system, comprising:
In a state in which the first audio device has the audio connection with the sound output control device established, and the second audio device has the audio connection with the sound output control device not established,
When the second audio device detects that the second audio device is powered on, the second audio device transmits a query command to inquire whether there is an audio device with which the audio connection has been established;
the first audio device transmits, in response to the inquiry command, a reply command to the second audio device, indicating that there is an audio device with which the audio connection has been established;
the second audio device transmits a change command instructing a change of the audio device to which the audio connection is established based on the reception of the answer command;
the first audio device releases the audio connection with the sound output control device based on receiving the change command, and based on the release of the audio connection, transmits a release command to the second audio device notifying that the audio connection has been released;
the second audio device executes a process for establishing the audio connection with the sound output control device based on the receipt of the release command.
Sound output system. The sound output system according to claim 1, wherein the sound output control device selectively uses an ARC (Audio Return Channel) function to establish the audio connection for an audio device that has acquired target device identification information that can identify the audio device as a target device for sound output control by the sound output control device. the second audio device executes a process for establishing the audio connection by acquiring the target device identification information;
The sound output system according to claim 2 , wherein the sound output control device establishes an audio connection with the second audio device from which the target device identification information has been obtained, by using the ARC function for the second audio device. The sound output system according to claim 2 or 3, wherein the second audio device transmits a notification command to the sound output control device to notify the sound output control device that the second audio device can operate as a target device for sound output control by the sound output control device at least either after the second audio device is communicatively connected to the sound output control device or after the second audio device acquires the target device identification information. The sound output system according to any one of claims 1 to 4, wherein the change command includes information that identifies the second audio device to which the audio connection is to be switched. The sound output system according to any one of claims 1 to 5, wherein the first audio device places the power supply of the first audio device in a standby state after transmitting the release command. the first audio device has an optical digital connection established with the sound output control device;
the sound output control device outputs sound from the first audio device with which the optical digital connection with the sound output control device is established in a state in which the audio connection with the first audio device is not established with the sound output control device;
A sound output system according to any one of claims 1 to 6. A sound output control device that outputs sound from an audio device with which an audio connection has been established, and a first audio device with which an audio connection has been established and which is communicably connected to the sound output control device,
a command control unit that controls transmission and reception of commands;
a connection control unit for controlling an audio connection with the sound output control device;
Equipped with
the command control unit, upon receiving from a second audio device with which the audio connection has not been established with the sound output control device an inquiry command inquiring as to whether or not there is an audio device with which the audio connection has been established, transmits to the second audio device a reply command indicating that there is an audio device with which the audio connection has been established;
the command control unit receives a change command instructing a change of the audio device to which the audio connection is established;
The connection control unit releases the audio connection with the sound output control device based on the reception of the change command,
the command control unit transmits, based on the release of the audio connection, a release command notifying the second audio device that the audio connection has been released;
First audio device. A second audio device is communicatively connected to a sound output control device that outputs sound from an audio device with which an audio connection has been established,
A power supply detection unit that detects when the power supply is on;
a command control unit that controls transmission and reception of commands;
a connection control unit for controlling an audio connection with the sound output control device;
Equipped with
the command control unit transmits an inquiry command to inquire whether or not there is an audio device with which the audio connection is established when the power detection unit detects that the power has been turned on;
the command control unit transmits a change command instructing to change the audio device to which the audio connection is established, based on receiving a reply command indicating that a first audio device with which the audio connection is established exists in response to the inquiry command;
the connection control unit executes a process for establishing the audio connection with the sound output control device based on the command control unit receiving a release command notifying that the first audio device has released the audio connection.
Second audio device. 1. An audio connection switching method executed by a sound output system, comprising: a sound output control device; and a plurality of audio devices including a first audio device and a second audio device communicably connected to the sound output control device, wherein the sound output control device causes one of the plurality of audio devices that is audio-connected to the sound output control device to output sound,
In a state in which the first audio device has the audio connection with the sound output control device established, and the second audio device has the audio connection with the sound output control device not established,
sending a query command when the second audio device detects that the second audio device has been powered on to inquire whether there is an audio device with which the audio connection has been established;
a step of the first audio device transmitting, in response to the inquiry command, a reply command to the second audio device, indicating that there is an audio device with which the audio connection has been established;
a step of transmitting a change command by the second audio device, based on receiving the answer command, for instructing a change of the audio device to which the audio connection is established;
the first audio device releasing an audio connection with the sound output control device based on receiving the change command, and transmitting a release command to the second audio device notifying the second audio device of the release of the audio connection based on the release of the audio connection;
executing a process by the second audio device to establish the audio connection with the sound output control device based on receiving the release command;
An audio connection switching method comprising:

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