Audio device and audio system

Abstract

To provide an audio device with which it is possible to prevent the degradation of audio reproduction signals over a longer time and generate an audio reproduction signal of the quality suitable for the genre of the musical piece to be reproduced.SOLUTION: In an audio device 1, a power supply control unit 16 supplies DC power outputted from an AC power supply connection unit 14 to units 10, 13, 16, 17 other than a reproduction unit 11 and an amplification unit 12 that affect the sound quality of an audio reproduction signal. Furthermore, the power supply control unit 16 supplies DC power outputted from a DC power supply source selected from among the AC power supply connection unit 14, a battery mounting unit 15a, and a battery mounting unit 15b and determined in advance corresponding to the genre of the music to be reproduced, to the reproduction unit 11 and the amplification unit 12 that affect the sound quality of an audio reproduction signal, in accordance with a wireless terminal 2 switching indication.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power control technology for audio devices.

Background Art

[0002] Generally, an audio device converts AC power supplied from an AC (Alternating Current) power source such as a household outlet into DC (Direct Current) power and supplies it to each part of the audio device.

[0003] However, the DC power converted from AC power generates ripple and noise due to the influence of the rectifying and smoothing circuit and the ground connection of the electronic circuit including the rectifying and smoothing circuit. Therefore, if this is used in the playback section or amplification section of an audio device, it may cause deterioration of the sound quality of the audio playback signal. Therefore, conventionally, a battery-powered audio device that supplies high-quality DC power supplied from a DC power source such as a dry battery or a rechargeable battery to each part of the audio device is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, some battery-powered audio devices as described in Patent Document 1 also support an AC power source such as a household outlet. When an AC power source is connected, the AC power source is prioritized as a drive source. Thereby, power consumption of the DC power source can be suppressed and the life of the DC power source can be extended. However, when the AC power source is prioritized, the sound quality of the audio playback signal deteriorates for the above reasons.

[0006] In addition, although dry batteries and rechargeable batteries are standard products, there are variations within an allowable range in battery capacity, output voltage, and output current depending on the manufacturer, materials used, internal structure, and the like. Also, the variation range of the output voltage and the change rate (responsiveness) of the output current during load fluctuations are different. For this reason, changing the manufacturer, type, etc. of the dry battery or rechargeable battery to be used may cause a change in the sound quality of the audio reproduction signal. However, conventional battery-powered audio devices do not consider this point.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide an audio device that can prevent deterioration of an audio reproduction signal over a longer period of time and can generate an audio reproduction signal with a sound quality suitable for the genre of the music to be reproduced.

Means for Solving the Problems

[0008] In order to solve the above problems, the audio device of the present invention switches the DC power supplied to each part of the DC power supply destination constituting the audio device to either an AC power connection part that converts the AC power supplied from the connected AC power supply into DC power and outputs it, or a battery mounting part that outputs the DC power supplied from the mounted battery. Specifically, among the parts constituting the audio device, for the reproduction part and the amplification part that affect the sound quality of the audio reproduction signal, in accordance with an instruction from a wireless terminal that functions as a controller of the audio device, DC power from a predetermined DC power supply source corresponding to the genre of the music to be reproduced is supplied, and for the other parts, the DC power output from the AC power connection part is supplied. Here, a plurality of battery mounting parts may be provided, and by mounting batteries with different manufacturers, types, etc. for each battery mounting part, the genres of music suitable for reproduction may be made different from each other between the battery mounting parts.

[0009] For example, the audio device of the present invention is an audio device including reproduction means for reproducing music and generating an audio reproduction signal, and amplification means for amplifying the audio reproduction signal. AC power supply connection means for converting AC power supplied from a connected AC (Alternating Current) power supply into DC (Direct Current) power and outputting it; Battery mounting means for outputting DC power supplied from a mounted battery; Power control means for supplying the DC power output from the AC power supply connection means and the battery mounting means to each DC power supply destination in the audio device; The power control means is Among the DC power supply destinations of the audio device, for DC power supply destinations other than the playback means and the amplification means, the DC power output from the AC power supply connection means is supplied, and for the playback means and the amplification means, in accordance with an instruction from a wireless terminal functioning as a controller of the audio device, DC power output from any one of the AC power supply connection means and the battery mounting means determined in advance according to the genre of the music to be played is supplied.

[0010] Also, the audio system of the present invention is The audio device, A wireless terminal functioning as a controller of the audio device; The wireless terminal is For each genre of music, supply source storage means in which either the AC power supply connection means or the battery mounting means is registered as a DC power supply source to the playback means and the amplification means; Switching instruction means for transmitting to the audio device a switching instruction accompanied by a designation of a DC power supply source stored in the supply source storage means associated with the music to be played; The power control means is In accordance with the switching instruction received from the wireless terminal, DC power output from the DC power supply source designated by the switching instruction is supplied to the playback means and the amplification means.

Advantages of the Invention

[0011] In the present invention, among each part constituting the audio device, DC power obtained by AC / DC conversion is supplied to each part other than the playback part and the amplification part that affect the sound quality of the audio playback signal. Therefore, it is possible to suppress the power consumption of the mounted battery and extend the battery life, thereby preventing the deterioration of the audio playback signal over a longer period of time.

[0012] Further, in the present invention, for the playback part and the amplification part that affect the sound quality of the audio playback signal, among the DC power obtained by AC / DC conversion and the DC power output from the mounted battery, DC power determined in advance according to the genre of the music to be played is supplied. Therefore, it is possible to generate an audio playback signal with a sound quality suitable for the genre of the music to be played.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, an embodiment of the present invention will be described.

[0015] FIG. 1 is a schematic configuration diagram of the audio system according to the present embodiment.

[0016] As shown in the figure, the audio system according to the present embodiment includes an audio device 1 and a wireless terminal 2 that functions as a controller of the audio device 1.

[0017] The audio device 1 plays the audio data of the music received from the wireless terminal 2 and outputs an audio playback signal from the speaker 3. Further, among each part of the DC power supply destination (refer to FIG. 2) constituting the audio device 1, for each part 10, 13, 16, 17 other than the playback part 11 and the amplification part 12 that affect the sound quality of the audio playback signal, DC (Direct Current) power obtained by converting AC (Alternating Current) power supplied from an AC power source such as a household outlet is supplied, and for the playback part 11 and the amplification part 12, in accordance with the instruction of the wireless terminal 2, either DC power obtained by converting AC power supplied from an AC power source such as a household outlet or DC power obtained from the batteries 18a and 18b attached to the audio device 1 is supplied.

[0018] The wireless terminal 2 downloads the audio data to be played back from the media server 4 via the access point 5 and the network 6, together with metadata including the music name, genre, etc. Then, according to the genre included in the metadata, a predetermined DC power supply source (either DC power obtained by converting AC power supplied from an AC power source such as a household outlet or DC power obtained from the batteries 18a and 18b attached to the audio device 1) is specified, and a switching instruction accompanied by the designation of the specified DC power supply source is transmitted to the audio device 1. Then, the audio data is transmitted to the audio device 1 to cause the audio device 1 to play the audio data.

[0019] Next, the details of the audio device 1 and the wireless terminal 2 constituting the audio system according to the present embodiment will be described.

[0020] First, the details of the audio device 1 will be described.

[0021] FIG. 2 is a schematic functional configuration diagram of the audio device 1.

[0022] As shown in the figure, the audio device 1 includes a wireless interface unit 10, a playback unit 11, an amplification unit 12, an output unit 13, an AC power connection unit 14, a plurality (for example, two) of battery mounting units 15a and 15b (hereinafter also simply referred to as the battery mounting unit 15), a power control unit 16, and a main control unit 17.

[0023] The wireless interface unit 10 is an interface for wirelessly connecting to the wireless terminal 2 via the access point 5.

[0024] The playback unit 11 plays the audio data received from the wireless terminal 2 via the wireless interface unit 10 and outputs the audio playback signal.

[0025] The amplification unit 12 amplifies the audio playback signal output from the playback unit 11.

[0026] The output unit 13 is connected to the speaker 3 and outputs the audio playback signal amplified by the amplification unit 12 from the speaker 3.

[0027] The AC power connection unit 14 is connected to an AC power source such as a household outlet via a plug, and converts and outputs the AC power supplied from this AC power source into DC power.

[0028] The battery mounting unit 15 is configured such that batteries 18a and 18b (hereinafter also simply referred to as the battery 18), such as dry batteries and rechargeable dry batteries, can be freely mounted thereon, and outputs the DC power supplied from the battery 18 mounted thereon.

[0029] The power control unit 16 controls the supply of the DC power output from the AC power connection unit 14 and the battery mounting unit 15 to each of the units 10 - 13, 17 that make up the audio device 1. Specifically, for units 10, 13, 16, 17 other than the playback unit 11 and the amplification unit 12 that affect the sound quality of the audio playback signal, the DC power output from the AC power connection unit 14 is supplied. Also, for the playback unit 11 and the amplification unit 12 that affect the sound quality of the audio playback signal, a DC power supply source predetermined according to the genre of the music to be played back is selected from among the AC power connection unit 14, the battery mounting unit 15a, and the battery mounting unit 15b according to the instruction of the main control unit 17, and the DC power output from this DC power supply source is supplied.

[0030] The main control unit 17 comprehensively controls each of the units 10 - 16 of the audio device 1.

[0031] Also, when the main control unit 17 receives a switching instruction from the wireless terminal 2 via the wireless interface unit 10, it instructs the power control unit 16 to supply the DC power output from the DC power supply source specified by this switching instruction among the AC power connection unit 14, the battery mounting unit 15a, and the battery mounting unit 15b to the playback unit 11 and the amplification unit 12.

[0032] Furthermore, when the main control unit 17 receives a playback instruction from the wireless terminal 2 via the wireless interface unit 10, it instructs the wireless interface unit 10, the playback unit 11, the amplification unit 12, and the output unit 13 to perform audio playback. In response to this, the wireless interface unit 10 receives audio data from the wireless terminal 2 and outputs it to the playback unit 11. The playback unit 11 plays back the audio data output from the wireless interface unit 10 and outputs the audio playback signal. The amplification unit 12 amplifies and outputs the audio playback signal output from the playback unit 11, and the output unit 13 outputs the audio playback signal output from the amplification unit 12 to the speaker 3.

[0033] In addition, the main control unit 17 monitors the remaining battery levels of the batteries 18a and 18b mounted on the battery mounting units 15a and 15b. When either one of the battery mounting units 15a and 15b is selected as the DC power supply source for the playback unit 11 and the amplifier unit 12, if the remaining battery level of the battery 18 mounted on the DC power supply source becomes less than a predetermined value and the remaining battery level of the battery 18 mounted on the other battery mounting unit 15 is equal to or greater than the predetermined value, the main control unit 17 instructs the power control unit 16 to use the other battery mounting unit 15 as the DC power supply source for the playback unit 11 and the amplifier unit 12. If the remaining battery level of the battery 18 mounted on the other battery mounting unit 15 is also less than the predetermined value, the main control unit 17 instructs the power control unit 16 to use the AC power connection unit 14 as the DC power supply source for the playback unit 11 and the amplifier unit 12.

[0034] The functional configuration of the audio device 1 shown in FIG. 2 is realized either hard by an integrated logic IC such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), or soft by a computer such as a DSP (Digital Signal Processor).

[0035] Next, the details of the wireless terminal 2 will be described.

[0036] FIG. 3 is a schematic functional configuration diagram of the wireless terminal 2.

[0037] As shown in the figure, the wireless terminal 2 includes a wireless interface unit 20, a man-machine interface unit 21, a music acquisition unit 22, a source storage unit 23, a switching instruction unit 24, a playback instruction unit 25, and a main control unit 26.

[0038] The wireless interface unit 20 is an interface for wirelessly connecting to the audio device 1 and the media server 4 via the access point 5.

[0039] The man-machine interface unit 21 is an interface for displaying information to the user and receiving various operations from the user, and is composed of an input / output device such as a display with a touch sensor, for example.

[0040] The music acquisition unit 22 accesses the media server 4 via the wireless interface unit 20 and downloads the audio data of the music together with metadata including the music name, genre, etc.

[0041] In the supply source storage unit 23, information on the DC power supply source for the playback unit 11 and the amplification unit 12 of the audio device 1 is stored for each genre of music.

[0042] FIG. 4 is a diagram schematically showing an example of the registration contents of the supply source storage unit 23.

[0043] As shown in the figure, in the supply source storage unit 23, a record 230 of the DC power supply source of the audio device 1 is stored for each genre of music. The record 230 of the DC power supply source has a field 231 in which the genre of the music is registered and a field 232 in which the DC power supply source (any one of the AC power connection part 14, the battery mounting part 15a, and the battery mounting part 15b) suitable for playing the audio data of this genre is registered.

[0044] In the present embodiment, as the battery 18 mounted on the battery mounting part 15 of the audio device 1, standard products such as dry batteries and rechargeable batteries are used. Standard products such as dry batteries and rechargeable batteries have variations in battery capacity, output voltage, and output current depending on the manufacturer, materials used, internal structure, etc. within their allowable ranges. Also, the variation range of the output voltage and the change speed (responsiveness) of the output current during load fluctuations are different.

[0045] Generally, a battery with a small variation width of the output voltage with respect to load fluctuations is suitable for classical, pops, etc., and a battery with good responsiveness of the output current with respect to load fluctuations is said to be suitable for rock, jazz, etc. Therefore, the battery 18 suitable for playing music of different genres is mounted on the battery mounting parts 15a and 15b, and for each genre of music, the information on the DC power supply source for the playback unit 11 and the amplification unit 12 of the audio device 1 is stored in the supply source storage unit 23. In the example shown in FIG. 4, the case where the battery 18a with a small variation width of the output voltage with respect to load fluctuations is mounted on the battery mounting part 15a and the battery 18b with good responsiveness of the output current with respect to load fluctuations is mounted on the battery mounting part 15b is illustrated.

[0046] In addition, for genres of music that do not require strict attention to the sound quality of the audio playback signal, by selecting the AC power connection part 14 as the DC power supply source for the playback unit 11 and the amplification unit 12 of the audio device 1, the consumption of the batteries 18a and 18b mounted on the battery mounting parts 15a and 15b can be suppressed and the battery life can be extended.

[0047] The switching instruction unit 24 transmits a switching instruction with a designation of the DC power supply source for the playback unit 11 and the amplification unit 12 of the audio device 1 to the audio device 1 via the wireless interface unit 20.

[0048] The playback instruction unit 25 transmits a playback instruction with the audio data to be played back to the audio device 1 via the wireless interface unit 20.

[0049] The main control unit 26 comprehensively controls each part 20 to 25 of the wireless terminal 2.

[0050] The functional configuration of the wireless terminal 2 shown in FIG. 3 is realized either hard by an integrated logic IC such as an ASIC or an FPGA, or realized software by a computer such as a DSP. Alternatively, in a mobile computer such as a smartphone or a tablet PC (Personal Computer) equipped with a CPU (Central Processing Unit), a memory, an auxiliary storage device such as a flash memory, and a wireless LAN (Local Area Network) adapter, the CPU loads a predetermined program from the auxiliary storage device onto the memory and executes it to realize it as a process.

[0051] FIG. 5 is a flowchart for explaining the operation of the wireless terminal 2.

[0052] When the main control unit 26 receives from the user a DC power supply source registration operation for the playback unit 11 and the amplification unit 12 of the audio device 1 via the man-machine interface unit 21 (YES in S100), it updates the supply source storage unit 23 (S101). Specifically, if a record 230 of the DC power supply source in which the genre of the music specified by the DC power supply source registration operation is registered in the field 231 is stored in the supply source storage unit 23, the registration content in the field 232 of this record 230 is changed to the DC power supply source (any one of the AC power connection unit 14, the battery mounting unit 15a, and the battery mounting unit 15b) specified by the DC power supply source registration operation. Also, if a record 230 of the DC power supply source in which the genre of the music specified by the DC power supply source registration operation is registered in the field 231 is not stored in the supply source storage unit 23, a new record 230 of the DC power supply source is added to the supply source storage unit 23, and the genre of the music and the DC power supply source specified by the DC power supply source registration operation are registered in the fields 231 and 232 of the added record 230, respectively.

[0053] Further, when the main control unit 26 receives from the user a playback operation accompanied by the designation of the name of the music piece to be played back (YES in S102) via the man-machine interface unit 21, it notifies the music piece acquisition unit 22 of the name of the music piece designated by this playback operation and instructs the acquisition of the music piece. In response to this, the music piece acquisition unit 22 accesses the media server 4 via the wireless interface unit 20, and downloads from the media server 4 the audio data of the name of the music piece notified from the main control unit 26, together with the metadata including the name and genre of the music piece (S103).

[0054] Next, the main control unit 26 specifies, as the DC power supply source for the playback unit 11 and the amplification unit 12 of the audio device 1, the DC power supply source stored in the supply source storage unit 23 that is associated with the genre included in the metadata downloaded from the media server 4 together with the audio data by the music piece acquisition unit 22 (S104). Then, it notifies the switching instruction unit 24 of the specified DC power supply source.

[0055] In response to this, the switching instruction unit 24 transmits, via the wireless interface unit 20 to the audio device 1, a switching instruction accompanied by the designation of the DC power supply source notified from the main control unit 26 (S105).

[0056] Then, the main control unit 26 passes the audio data downloaded from the media server 4 by the music piece acquisition unit 22 to the playback instruction unit 25 and instructs playback. In response to this, the playback instruction unit 25 transmits, via the wireless interface unit 20 to the audio device 1, a playback instruction accompanied by the audio data received from the main control unit 26 (S106).

[0057] The above describes one embodiment of the present invention.

[0058] In this embodiment, in the audio device 1, DC power output from the AC power connection unit 14 is supplied to each unit 10, 13, 16, 17 other than the playback unit 11 and the amplification unit 12 that affect the sound quality of the audio playback signal. Therefore, according to this embodiment, it is possible to suppress the power consumption of the battery 18 mounted on the battery mounting unit 15 and extend the battery life. As a result, deterioration of the audio playback signal can be prevented over a longer period of time.

[0059] Also, in this embodiment, in the audio device 1, for the playback unit 11 and the amplification unit 12 that affect the sound quality of the audio playback signal, a DC power supply source predetermined according to the genre of the music to be played is selected from among the AC power connection unit 14, the battery mounting unit 15a, and the battery mounting unit 15b according to an instruction from the wireless terminal 2, and DC power output from this DC power supply source is supplied. Therefore, according to this embodiment, it is possible to generate an audio playback signal with a sound quality suitable for the genre of the music to be played.

[0060] Also, in this embodiment, the audio device 1 monitors the remaining battery levels of the batteries 18a and 18b mounted on the battery mounting units 15a and 15b. When either one of the battery mounting units 15a and 15b is selected as the DC power supply source for the playback unit 11 and the amplification unit 12, when the remaining battery level of the battery 18 mounted on the DC power supply source becomes less than a predetermined value, the other battery mounting unit 15 is switched to the DC power supply source for the playback unit 11 and the amplification unit 12. Here, if the remaining battery level of the battery 18 mounted on the other battery mounting unit 15 is also less than the predetermined value, the AC power connection unit 14 is switched to the DC power supply source for the playback unit 11 and the amplification unit 12. For this reason, when it becomes necessary to switch the DC power supply source during playback, it is possible to suppress the influence on the sound quality of the audio playback signal due to this switching of the DC power supply source.

[0061] Also, in the present embodiment, for each genre of music, in the wireless terminal 2, a DC power supply source to be supplied to the playback unit 11 and the amplification unit 12 is registered among the AC power connection unit 14, the battery mounting unit 15a, and the battery mounting unit 15b. When the wireless terminal 2 receives a playback operation from the user, it transmits a switching instruction accompanied by the designation of the DC power supply source registered in association with the genre of the music to be played back to the audio device 1. Then, the audio device 1 supplies the DC power output from a predetermined DC power supply source according to the genre of the music to be played back to the playback unit 11 and the amplification unit 12 that affect the sound quality of the audio playback signal in accordance with the switching instruction of the wireless terminal 2. Therefore, according to the present embodiment, since the user only needs to perform a playback operation and a predetermined DC power supply source is automatically selected according to the genre of the music to be played back, the convenience is improved.

[0062] Note that the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0063] For example, in the above-described embodiment, the wireless terminal 2 updates the registration content (the correspondence relationship between the genre of music and the DC power supply source) in the supply source storage unit 23 according to the DC power supply source registration operation received from the user. However, the present invention is not limited to this.

[0064] In the audio device 1, the main control unit 17 may perform a characteristic test of the battery 18 mounted on each battery mounting part 15 (a test including measurement of output voltage, output current, variation width of output voltage with respect to load variation, and change speed of output current with respect to load variation) according to a test instruction received from the wireless terminal 2, and transmit the test result to the wireless terminal 2. On the other hand, the wireless terminal 2 is provided with a battery characteristic storage unit in which battery characteristics (battery characteristics including at least one of output voltage, output current, variation width of output voltage with respect to load variation, and change speed of output current with respect to load variation) suitable for reproducing music of each genre are stored. The main control unit 26 of the wireless terminal 2 transmits a test instruction to the audio device 1 according to a test start operation received from the user via the man-machine interface unit 21, acquires the test result of the battery 18 mounted on the battery mounting part 15 of the audio device 1 for each battery mounting part 15 from the audio device 1, and associates the battery mounting part 15 on which the battery 18 to be tested is mounted as a DC power supply source with the genre of music stored in the battery characteristic storage unit associated with the battery characteristics indicated by the test result, and registers it in the supply source storage unit 23. By doing so, the user does not need to perform a DC power supply source registration operation, and the convenience is further improved.

[0065] Also, in the server, for each battery product information (manufacturer name, product name, model number, etc.), a genre of music suitable for using the battery specified by this product information as a DC power supply source for reproduction is registered. For example, when the battery 18 is mounted on the battery mounting part 15 of the audio device, etc., the wireless terminal receives the designation of the product information of the mounted battery 18 for each battery mounting part 15 of the audio device from the user, makes an inquiry to the server about the genre of music associated with the specified product information, and based on the information (music genre) returned from the server and the mounting destination (battery mounting part 15) of the battery being inquired, the registration content (correspondence relationship between music genre and DC power supply source) of the supply source storage unit 23 may be automatically updated.

[0066] Also, in the above-described embodiment, for each genre of music, a DC power supply source to be supplied to the playback unit 11 and the amplification unit 12 of the audio device 1 is registered in the wireless terminal 2. When the wireless terminal 2 receives a playback operation from the user, it transmits a switching instruction with the designation of the DC power supply source registered in association with the genre of the music to be played back to the audio device 1. However, the present invention is not limited to this. For example, in the wireless terminal 2, for each battery mounting portion 15 of the audio device 1, an audio manufacturer (for example, an audio manufacturer highly evaluated for playing classical music, an audio manufacturer highly evaluated for playing rock, etc.) associated with the sound quality of the audio reproduction signal obtained by DC power supply from the battery 18 mounted on the battery mounting portion 15 may be registered in association. Then, when the wireless terminal 2 receives a designation of an audio manufacturer from the user, it transmits a switching instruction designating the battery mounting portion 15 associated with the designated audio manufacturer as the DC power supply source to the audio device 1.

[0067] Also, in the above-described embodiment, the case where the audio device 1 is provided with two battery mounting portions 15a and 15b has been described as an example, but the number of battery mounting portions 15 may be one or three or more.

[0068] Also, in the above embodiment, the audio device 1 monitors the remaining battery levels of the batteries 18a and 18b mounted on the battery mounting portions 15a and 15b, and when either one of the battery mounting portions 15a and 15b is selected as the DC power supply source for the playback unit 11 and the amplifier unit 12, when the remaining battery level of the battery 18 mounted on the DC power supply source becomes less than a predetermined value, the DC power supply to the playback unit 11 and the amplifier unit 12 is switched to another DC power supply source. However, the present invention is not limited to this. For example, as follows, the DC power supply to the playback unit 11 and the amplifier unit 12 may be sequentially switched to another DC power supply source. That is, when the remaining battery level of the battery 18 mounted on the DC power supply source for the playback unit 11 and the amplifier unit 12 becomes less than a first predetermined value, among the playback unit 11 and the amplifier unit 12, the DC power supply to the playback unit 11 is first switched to another DC power supply source. Further, if the remaining battery level of the battery that continues to supply DC power to the amplifier unit 12 becomes less than a second predetermined value that is lower than the first predetermined value, the DC power supply to the amplifier unit 12 is also switched to another DC power supply source. By doing so, it becomes possible to use the battery 18 that is the initial DC power supply source, that is, the battery suitable for the music to be played back, for a longer time with respect to the amplifier unit 12, which is considered to have the greatest impact on the sound quality of the audio playback signal, and the influence on the sound quality of the audio playback signal can be further suppressed.

[0069] Also, in this embodiment, the wireless terminal 2 downloads the audio data to be played back from the media server 4 together with its metadata, and transmits a playback instruction accompanied by this audio data to the audio device 1. However, the present invention is not limited to this. The wireless terminal 2 may transmit a playback instruction accompanied by a designation of the playback target to the audio device 1 in accordance with a playback operation received from the user, and the audio device 1 may download the audio data of the playback target designated by the playback instruction received from the wireless terminal 2 from the media server 4 together with its metadata. Then, the audio device 1 transmits the metadata to the wireless terminal 2, and the wireless terminal 2 transmits a switching instruction accompanied by a designation of the DC power supply source associated with the genre included in the metadata to the audio device 1. In response to this, the audio device 1 switches the DC power supply source in accordance with the switching instruction received from the wireless terminal 2, and then plays and outputs the downloaded audio data.

[0070] Furthermore, in this embodiment, the audio device 1 may incorporate the speaker 3.

Explanation of Reference Numerals

[0071] 1: Audio device 2: Wireless terminal 3: Speaker 4: Media server 5: Access point 6: Network 10: Wireless interface unit 11: Playback unit 12: Amplification unit 13: Output unit 14: AC power connection unit 15a, 15b: Battery mounting part 16: Power control unit 17: Main control unit 18a, 18b: Batteries 20: Wireless interface unit 21: Man-machine interface unit 22: Music acquisition unit 23: Supply source storage unit 24: Switching instruction unit 25: Playback instruction unit 26: Main control unit

Claims

1. An audio device comprising: playback means for playing a music piece to generate an audio playback signal; and amplification means for amplifying the audio playback signal, AC power supply connection means for converting AC power supplied from a connected AC (Alternating Current) power supply into DC (Direct Current) power and outputting the DC power, battery mounting means for outputting DC power supplied from a mounted battery, power control means for supplying the DC power output from the AC power supply connection means and the battery mounting means to each of the DC power supply destinations in the audio device, wherein the power control means, supplies the DC power output from the AC power supply connection means to each of the DC power supply destinations other than the playback means and the amplification means among the DC power supply destinations of the audio device, and supplies the DC power output from any one of the AC power supply connection means and the battery mounting means determined in advance according to the genre of the music piece to be played, in accordance with an instruction from a wireless terminal functioning as a controller of the audio device, to the playback means and the amplification means An audio device characterized by the above.

2. The audio device according to claim 1, having a plurality of the battery mounting means, wherein the power control means, in accordance with an instruction from the wireless terminal, supplies the DC power output from any one of the AC power supply connection means and the plurality of battery mounting means determined in advance according to the genre of the music piece to be played, to the playback means and the amplification means An audio device characterized by the above.

3. The audio device according to claim 2, further comprising remaining amount monitoring means for monitoring the remaining amount of the battery mounted on each of the plurality of battery mounting means, wherein the power control means, while supplying the DC power output from any one of the plurality of battery mounting means to the playback means and the amplification means, when the monitoring result by the remaining amount monitoring means of the remaining amount of the battery mounted on the battery mounting means which is the DC power supply source becomes less than a predetermined value, if there is another battery mounting means among the plurality of battery mounting means on which a battery having a monitoring result by the remaining amount monitoring means of a predetermined value or more is mounted, supplies the DC power output from the battery mounting means to the playback means and the amplification means An audio device characterized by the above.

4. The audio device according to any one of claims 1 to 3, and a wireless terminal that functions as a controller of the audio device, an audio system comprising: wherein the wireless terminal for each genre of music, a supply source storage means in which any one of the AC power connection means and the battery mounting means is registered as a DC power supply source to the playback means and the amplification means; a switching instruction means for transmitting to the audio device a switching instruction accompanied by a designation of a DC power supply source stored in the supply source storage means associated with a music to be played back; wherein the power control means in accordance with the switching instruction received from the wireless terminal, supplies DC power output from the DC power supply source designated by the switching instruction to the playback means and the amplification means An audio system characterized by that.

5. The audio system according to claim 4, wherein the audio device in accordance with a test instruction received from the wireless terminal, further has a test means for performing a test including measurement of an output voltage, an output current, a variation range of the output voltage with respect to a load variation, and a change rate of the output current with respect to a load variation of a battery mounted in the battery mounting means, and transmitting a test result to the wireless terminal; wherein the wireless terminal for each genre of music, battery characteristic storage means storing battery characteristics including at least one of an output voltage, an output current, a variation range of the output voltage with respect to a load variation, and a change rate of the output current with respect to a load variation of a battery suitable for playing music of the genre; a test result acquisition means for transmitting the test instruction to the audio device and acquiring a test result of a battery mounted in the battery mounting means from the audio device; a supply source update means for registering the battery mounting means as a DC power supply source to the playback means and the amplification means in the supply source storage means in association with the genre of music stored in the battery characteristic storage means associated with the battery characteristics indicated by the test result acquired by the test result acquisition means; An audio system characterized by that.

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