Patent Publication Number: US-8526631-B2

Title: Audio device

Description:
TECHNICAL FIELD 
     The present invention relates to an audio device. 
     BACKGROUND ART 
     In recent years, portable audio devices, which have functions to store music data being distributed via a communication network or read down from a music CD (Compact Disk) into an internal storage media and to replay audio on the basis of data stored upon such storage media, have become commercially available. Such a portable audio device is compact and also light in weight, and they have become very widespread, since it is possible to enjoy music and so on anywhere without difficulty. 
     As the portable audio device, many different types of model are currently supplied to be utilized on a portable basis for enjoying music outdoors as well as for enjoying the music under a satisfactory audio replay environment, wherein the portable audio device is connected to another audio device such as a home audio device or a car audio device or the like, each of which has perfected speakers and so on. Moreover, as an audio device to which a portable audio device can be connected, a type of device has also come on the market which has the function to supply charging power to a portable audio device to which it is connected, because generally a portable audio device can be charged up with electrical power. 
     As a technique related to such an audio device which is endowed with a function of supplying charging power to a portable audio device, the technique for enhancing the ease of use for performing audio replay by using the data stored in the storage medium in the portable audio device, while charging (refer to Patent Reference #1; hereinafter it is referred to as the “prior art”). In the technique disclosed in the prior art, while the portable audio device is charged, actuation input is performed by using actuation input part, not to an inherent actuation input part configured to be” provided to the portable audio device, but rather to an actuation input part configured to be provided to the audio device having the function for supplying charging power. Then, audio replay may be performed by using the data stored in the internal storage medium of the portable audio device, and thereby replay audio may be outputted from the speakers of the audio device.
     Patent Reference #1: Japanese Patent Publication 3,714,882.   

     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, in the above described prior art, if a novel type of the portable audio device having extended functions are appeared upon the market, it becomes necessary to perform a version upgrade on the audio device in order to be able to deal with this novel type of device. If the version upgrade is not performed, operation control of the portable audio device with the audio device as normal becomes impossible. As a result, it may become impossible to perform the actuation input to the actuation input part configured to provide to the audio device to perform audio replay by using the data being stored upon the internal storage medium of the portable audio device, while charging up. 
     Moreover, according to the circumstances of the user, an inherent actuation input part of the portable audio device is sometimes preferably used for inputting a control command for audio replay by using the data stored upon the storage medium in the portable audio device. On the other hand, an actuation input part of the audio device to which the portable audio device is connected is sometimes preferably used. 
     Due to this, there is a requirement for a technique for outputting the replay audio from the speaker of the audio device by using the data stored in the storage medium in the portable audio device. Moreover, there is a requirement for a technique for performing the actuation input for replaying audio by using the data being stored upon the storage medium in the portable audio device through the most preferably actuation input part for the users. As one of issues to be solved by the invention, it is mentioned such as the technique to respond the needs. 
     The present invention has been conceived in consideration of the circumstances described above. The object of the present invention is to provide a novel audio device, being operated together with the portable audio device and improve the convenience for the user. 
     Means for Solving the Problem 
     The audio device of the present invention is an audio device which performs replay of audio based on an external audio signal outputted from a portable audio device, comprising: a power supply part configured to supply power of a predetermined voltage to said portable audio device; an operability notification part configured to notify operability information to said portable audio device, wherein the operability information specifies whether or not inherent actuation input using an inherent actuation input part configured to provide to said portable audio device is to be possible; a control part configured to control the content of notification from said operability notification part to said portable audio device; and an audio replay part configured to replay audio depending on said external audio signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram schematically showing the configuration of an audio device according to an embodiment of the present invention; 
         FIG. 2  is a block diagram showing the configuration of a control unit of  FIG. 1 ; 
         FIG. 3  is a block diagram showing the configuration of a function reporting unit of  FIG. 2 ; 
         FIG. 4  is a block diagram showing the configuration of an audio output selection unit of  FIG. 2 ; and 
         FIG. 5  is a figure for explanation of inputs to and outputs from a power supply unit of  FIG. 1 . 
     
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     In the following, an embodiment of the present invention will be explained with reference to  FIGS. 1 to 5 . Note that, in the following explanation and drawings, the same reference symbols are appended to elements which are the same or equivalent, and duplicated explanation will be omitted. 
     Configuration 
     In  FIG. 1 , the schematic configuration of an audio device  100  according to the embodiment is shown as a block diagram. Note that, in the following explanation, it will be supposed that the audio device  100  is a device which is mounted to a vehicle CR. 
     As shown in  FIG. 1 , the audio device  100  operate by using power SEP which is supplied from a vehicle power supply  920  such as a vehicle battery or the like. The vehicle power supply  920  includes a back up power supply and an accessory power supply. One of the power supplies is chosen depending on the operating status of the vehicle, which is determined by rotational operation of the key inserted in the key cylinder  910  by the user, as a power source. Note that the rotational state of the key inserted into the key cylinder  910  is reported from the key cylinder  910  to the audio device  100  as key position information KPD. 
     Moreover, a portable audio device  500  is connectable to the audio device  100  via a cable  610 . The portable audio device  500  decides whether or not actuation input through an actuation input part  510  is possible based on a function setting report FRP reported from the audio device  100 . If the result of the decision is affirmative, then the portable audio device  500  performs processing for audio replay or for display on a display part  520 , according to the actuation input performed on the actuation input part  510  by itself. On the other hand, if the result of the decision is negative, then the portable audio device  500  performs the processing for audio replay or for display on the display part  520 , according to control commands CTS from the audio device  100 . Moreover, the portable audio device  500  charges up its internal battery using charging power CPW supplied from the audio device  100 . 
     The portable audio device  500  has the function for replaying audio content recorded on an audio recording medium. When it is connected to the audio device  100  via the cable  610  connected to a connector  530 , it supplies analog audio signals PAS L  and PAS R  to the audio device  100 . 
     As shown in  FIG. 1 , the audio device  100  comprises a replay processing unit  160  and a power supply unit  170  as a power supply part. Moreover, the audio device  100  comprises a connector  180  to which the cable  610  is connected. 
     The replay processing unit  160  comprises a control unit  110 , a drive unit  120  as an internal sound generation part, and a left speaker  130   L  and a right speaker  130   R  as audio replay part. Moreover, the audio device  100  comprises a display unit  140 , an actuation input unit  150  which serves as an actuation input part, and a power supply unit  170  which serves as a power supply part. 
     Note that the above described elements  120  through  150  and  170  are connected to the control unit  110 , and operate under the control of the control unit  110 . 
     The control unit  110  controls the audio device  100  as a whole. The details of the control unit  110  will be described hereinafter. 
     When the drive unit  120  is received the replay command for the audio content from the control unit  110  under the condition wherein a recording medium, on which some audio content is recorded, is loaded to the drive unit  120 , it reads out the audio content, specified by the command, from the recording medium. The read out result of the audio content is sent to the control unit  110  as content data CTD, an audio signal. 
     The left speaker  130   L  performs replay output of the audio corresponding to the left audio signal AOS L  from the control unit  110 . The right speaker  130   R  performs replay output of the audio corresponding to the left audio signal AOS R  from the control unit  110 . 
     The display unit  140  comprises: (i) a display device such as a liquid crystal display panel, an organic EL (Electro-Luminescence) panel, a PDP (Plasma Display Panel), and the like; (ii) a display controller such as a graphic renderer and the like for performing overall control of the display unit  140 , based on display control data sent from the control unit  110 ; and (iii) a display image memory or the like for storing display image data. The display unit  140  displays actuation guidance information and so on, under the control of the control unit  110 . 
     The actuation input unit  150  is composed of a key unit arranged on the main body portion of the audio device  110 , or of a remote input device and the like having a key unit. Here, as the key unit provided upon the main body portion, a touch panel arranged on the display device of the display unit  140  may be used. Note that, instead of a structure having the key unit, the structure for audio input may also be used. 
     The details of the operation of the audio device  100  are set, according to the input actuation to the actuation input unit  150  by the user. For example, setting for audio content, setting for audio content search, volume adjustment for the audio signals outputted from the speakers  130   L  and  130   R , and so forth may be performed by using the actuation input unit  150 , which sends this input content to the control unit  110 . 
     The control unit  110  performs overall control of the audio device  100 , as described above. As shown in  FIG. 2 , the control unit  110  comprises a control processing unit  111  as a control part, and a function reporting unit  112  as an operability notification part. The control unit  110  comprises an audio processing unit  113 , an audio output selection unit  114  as a signal selection part, and a volume adjustment unit  115  as a volume adjustment part. 
     The control processing unit  111  analyzes the actuation input data IPD received from the actuation input unit  150 . Then, based on the results of the analysis, the control processing unit  111  controls the power supply unit  170 , the function reporting unit  112 , the audio processing unit  113 , the audio output selection unit  114 , and the volume adjustment unit  115 . Commands issued in the control include a power supply control command PSC for the power supply unit  170 , a function reporting control command SWC for the function reporting unit  112 , an audio content processing control command APC for the audio processing unit  113 , an output audio selection control command ASC for the audio output selection unit  114 , and a volume adjustment control command VLC for the volume adjustment unit  115 . 
     If the control processing unit  111  let the function reporting unit  112  send a function report that it is impossible to perform actuation input through the actuation input part  510  arranged in the portable audio device  500 , the control processing unit  111  outputs control commands CTS for controlling the operation of the portable audio device  500  to a terminal  181   c  of the connector  180 . As a result, the control commands CTS is sent to the portable audio device  500  via the cable  610 . 
     The function reporting unit  112  reports to the portable audio device  500  function setting information FRP (expressed as two signal lines FRP H  and FRP L ), which is operability information showing whether or not actuation input is possible by using the actuation input part  510  arranged on the portable audio device  500  via the cable  610 . In this embodiment, the resistance value between the signal line FRP H  and the signal line FRP L  is varied depending on a function reporting control command SWC from the control processing unit  111 , thereby reporting to the portable audio device  500  as to whether or not actuation input is possible through the actuation input part  510 . 
     As shown in  FIG. 3 , the function reporting unit  112  comprises resistance elements  211   1  and  211   2  and a switching element  212 . The resistance element  211   1  has a resistance value R 1 , and the resistance element  211   2  has a resistance value R 2 . The switching element  212  has two terminals, one of which is connected to a terminal  181   d  of the connector  180 , and the other is connected to a terminal  181   e  of the connector  180 . The ON/OFF operation of the switching element  212  is performed according to the function reporting control commands SWC from the control processing unit  111 . 
     Note that the portable audio device  500  determines the functions of the audio device  100 , namely, the type of the audio device  100 , by measuring the resistance value between the terminals  181   d  and  181   e  of the connector  180 . In other words, when the switching element  212  is OFF, then the portable audio device  500  recognizes that the audio device  100  is a mere charging up device based on the resistance value between the terminals  181   d  and  181   e  (R 1 +R 2 ) thereby deciding that actuation input through the actuation input part  510  is possible. When the switching element  212  is ON, the portable audio device  500  recognizes that this audio device  100  is a remote actuation device based on the resistance value between the terminals  181   d  and  181   e  (R 1 ), and the operation for the portable audio device  500  is placed under the control by the audio device  100 . Then, the portable audio device  500  decides that that actuation input through the actuation input part  510  arranged on the portable audio device  500  is impossible. 
     Returning to  FIG. 2 , when the audio processing unit  113  is received a report that the content including audio content to be replayed is designated from the actuation input unit  150 , the audio processing unit  113  reads out the content data CTD corresponding to the content to be replayed from the drive unit  120  according to an audio content processing control command APC. Then it generates digital audio sound data signal from the content data CTD read out from the drive unit  120 . Subsequently, the audio processing unit  113  analyzes the generated digital audio data signal, and separates it according to channel setting information included in the digital audio data signal for supplying individual digital audio data signals to the above described speakers  130   L  and  130   R . 
     The audio processing unit  113  includes two DA (Digital to Analog) converters which have mutually similar structures, corresponding to the above two digital audio data signals. The audio processing unit  113  converts the digital audio data signals separated as described above into analog audio signals. In this way, two analog audio signals PDS L  and PDS R  separated for the two speakers  130   L  and  130   R  respectively are outputted to the audio output selection unit  114 . 
     According to an output audio selection control command ASC from the control processing unit  111 , the audio output selection unit  114  selects either one of the analog audio signals PAS L  and PAS R , which are the audio signals outputted from the portable audio device  500 , or the analog audio signals PDS L  and PDS R  which have sent from the audio processing unit  113 , as the audio to be outputted from the speakers  130   L  and  130   R  respectively. 
     As shown in  FIG. 4 , the audio output selection unit  114  comprises switching elements  221   L  and  221   R . The switching element  221   L  is used for selecting the audio to be output from the speaker  130   L , while the switching element  221   R  is used for selecting the audio to be output from the speaker  130   R . 
     The switching element  221   L  has terminals A, B, and C. On the switching element  221   L , the terminal A is connected to a terminal  181   a  of the connector  180 , and the terminal B is connected to the audio processing unit  113 . The terminal C is connected to the volume adjustment unit  115 . On this switching element  221   L , the analog audio signal PAS L  output from the portable audio device  500  is supplied to the terminal A, while the analog audio signal PDS L  from the audio processing unit  113  is supplied to the terminal B. 
     Similarly to the switching element  221   L , the switching element  221   R  has terminals A, B, and C. On this switching element  221   R , the terminal A is connected to an output terminal  181   b  of the connector  180 , and the terminal B is connected to the audio processing unit  113 . The terminal C is connected to the volume adjustment unit  115 . On this switching element  221   R , the analog audio signal PAS R  output from the portable audio device  500  is supplied to the terminal A, while the analog audio signal PDS R  from the audio processing unit  113  is supplied to the terminal B. 
     Each of these switching elements  221   L  and  221   R  operates according to the audio selection control command ASC from the control processing unit  111 . The audio signal selected by the audio output selection unit  114  is sent from the C terminals of the switching elements  221   L  and  221   R  to the volume adjustment unit  115  as the analog audio signals PBS L  and PBS R . 
     Returning to  FIG. 2 , the volume adjustment unit  115  adjusts the volumes of the analog audio signals PBS L  and PBS R  sent from the audio output selection unit  114 , according to the volume adjustment control commands VLC from the control processing unit  111 . The volume adjustment unit  115  comprises two amplifiers having mutually similar structures, corresponding to the speakers  130   L  and  130   R , thereby adjusting the levels of the analog audio signals. The results of the adjustment are output towards the speakers  130   L  and  130   R  as a left audio signal AOS L  and a right audio signal AOS R . 
     Returning to  FIG. 1 , the power supply unit  170  uses power SEP supplied from the vehicle power supply  920  to generate power APW for the operation of the replay processing unit  160 , and charging power CPW being supplied to the portable audio device  500 . Here, the generation of the charging power CPW is performed according to a power supply control command PSC from the control processing unit  111 . 
     Note that, as shown in  FIG. 5 , the power SEP is supplied at two levels: a higher supply level SEP H  and a lower supply level SEP H  [sic]. In this embodiment, the lower supply level SEP L  is set as ground level. 
     The power supply unit  170  supplies the operating power APW to the replay processing unit  160  at two levels: a higher supply level APW H  and a lower supply level APW L . In this embodiment, the low supply level APW L  is set as the ground level. The potential difference between the lower supply level APW L  and the higher supply level APW H  is an appropriate voltage value for the replay processing unit  160  to operate. 
     The power supply unit  170  supplies the charging power CPW to the terminals  181   f  and  181   g  of the connector  180  at two levels: a higher supply level CPW H  and a lower supply level CPW L . In this embodiment, the lower supply level CPW L  is set as ground level, and the potential difference between the lower supply level CPW L  and the higher supply level CPW H  is an appropriate voltage value for charging of the portable audio device  500 . 
     Note that, in this embodiment, as the above described vehicle operational states, there are mentioned such as an OFF state in which only operating power is supplied from the back up power supply, an accessory ON state in which operating power is supplied from both of the back up power supply and from the accessory power supply, an ignition ON state in which operating power is also supplied from the accessory power supply to a control system vehicle device, and a starting state in which the vehicle is put into a state in which it is capable of moving. The control processing unit  111  issues a power supply control command PSC that the power should be supplied to the power supply unit  170  when the operational state of the vehicle is any one of the states among the accessory ON state, the ignition ON state, and the starting state. When the operational state of the vehicle is the OFF state, the control processing unit  111  does not issue any power supply control command that the power should be supplied to the power supply unit  170 . Therefore, the charging power CPW is not supplied to the portable audio device  500 . 
     (Operation) 
     Next, the operation of the audio device  100  having the configuration described above will be explained, mainly focusing on the replay of an external audio signal which is output from the portable audio device  500 . 
     As a premise, the portable audio device  500  is connected to the audio device  100  via the cable  610 . The analog audio signals PAS L  and PAS R  from the portable audio device  500  selected in the audio output selection unit  114  is output as the analog audio signals PBS L  and PBS R  in the audio device  100 . The analog audio signals PAS L  and PAS R  is selected in the audio output selection unit  114  by using that the actuation input should make output replay audio based on the analog audio signals PAS L  and PAS R  from the speakers  130   L  and  130   R  through the actuation input unit  150 , and the control processing unit  111  sends that the audio output selection control command ASC for selecting the audio signals outputted from the portable audio device  500  to the audio output selection unit  114 . Note that, in this case, the A terminals and the C terminals of the switching elements  221   L  and  221   R  are electrically connected in the audio output selection unit  114 . 
     Insertion of the key to key cylinder  910  and rotation of the key make the operational state of the vehicle, which is depending on the key position, set one state among the accessory ON state, the ignition ON state, and the starting state. In these states, the accessory power supply provides the operation power to the audio device  100 , and the audio device  100  executes normal operation. The operational state of the vehicle is sent to the control processing unit  111  from the key cylinder  910  as the key position information KPD. 
     After the control processing unit  111  recognizes the operational state of the vehicle is any one of the accessory ON state, the ignition ON state, and the starting state based on the key position information KPD, the control processing unit  111  sends to the power supply unit  170  a power supply control command PSC for supplying the power to the portable audio device  500 . The power supply unit  170  that received the power supply control command PSC generates the charging power CPW from the power SEP supplied from the vehicle power supply  920 . Thus, the charging power CPW generated is supplied to the portable audio device  500  via the connector  180  and the cable  610 . As a result, charging up of the battery in the portable audio device  500  is performed. 
     Note that the power supply unit  170  generates the power APW for operation of the replay processing unit  160  to supply it to the replay processing unit  160 , irrespective of whether or not it has received any power supply control command PSC. 
     During execution of normal operation in the audio device, the input that allows user to enable for performing actuation input utilizing the actuation part  510  arranged on the portable audio device  500  by using the actuation input unit  150  is performed, then the actuation input data IPD showing above is sent to the control processing unit  111 . When the control processing unit  111  receives the actuation input data IPD, it sends a function reporting control command SWC for switching element  212  should be turned OFF to the function reporting unit  112  (refer to  FIG. 3 ). As a result, the portable audio device  500  recognizes the audio device  100  as a charging device. Thus, the portable audio device  500  recognizes the audio device  100  as a charging device, thereby the actuation input by using the actuation unit arranged on the portable audio device  500  becomes possible. In this state, when the user utilizes the actuation part  510  of the portable audio device  500  to replay the audio content recorded on the internal audio recording medium in the portable audio device  500 ; the analog audio signals PAS L  and PAS R , audio signals, are sent to the audio device  100  via the cable  610 . 
     On the other hand, during execution of normal operation in the audio device  100 , the input that prevents user to enable for performing actuation input utilizing the operation part  510  arranged on the portable audio device  500  by using the actuation input unit  150  is performed, then the actuation input data IPD showing above is sent to the control processing unit  111 . After receiving of the actuation input data IPD, the control processing unit  111  sends to the function reporting unit  112  the function reporting control command SWC for switching element  212  should be turned ON (refer to  FIG. 3 ). As a result, the portable audio device  500  recognizes the audio device  100  as a remote actuation device. Thus, the portable audio device  500  recognizes the audio device  100  as a remote actuation device, thereby the actuation input by using the actuation part arranged on the portable audio device  500  becomes impossible, while remote actuation with the audio device  100  becomes possible. 
     In this state, when the user utilizes the actuation unit  150  of the audio device  100  to replay the audio content recorded on the internal audio recording medium in the portable audio device  500 , the analog audio signals PAS L  and PAS R , the audio signals, are sent to the audio device  100  via the cable  610 . 
     In the audio device  100  which has received the analog audio signals PAS L  and PAS R , as described above, these analog audio signals PAS L , and PAS R  are selected by the audio output selection unit  114 , and are sent to the volume adjustment unit  115  as the analog audio signals PBS L  and PBS R . 
     The volume adjustment unit  115  adjusts the volume of the analog audio signals PBS L  and PBS R  sent from the audio output selection unit  114 , according to the volume adjustment control VLC from the control processing unit  111 . Then, the left audio signal and the right audio signal AOS L  and AOS R , which are obtained as the result from the adjustment, are output to the speakers  130   L  and  130   R  respectively. Then, replay audio based on the result on the adjustment is output from the speakers  130   L  and  130   R  towards the music space. 
     Note that, if actuation input for making the replay audio based on the analog audio signals PDS L  and PDS R  output from the speakers  130   L  and  130   R  is performed by using the actuation input unit  150 , then the audio bore by the content data CTD read by the drive unit  120  is reproduced and output from the speakers  130   L  and  130   R . In this case, according to the actuation input for outputting the replay audio based on the analog audio signals PDS L  and PDS R , the control processing unit  111  sends to the audio output selection unit  114  an output audio selection control command ASC for selecting the audio signals output from the audio processing unit  113 . As a result, the B terminal and the C terminal of the switching elements  221   L  and those on the element  221   R  in the audio output selection unit  114  are electrically connected. 
     In this state, when the user performs input of a replay command for audio content, specifying the audio content recorded on the recording medium loaded into the drive unit  120 , to the actuation input unit  150 , the content data CTD for the audio content is sent from the drive unit  120  to the audio processing unit  113 . In the audio processing unit  113 , the content data CTD is processed as described above to generate analog audio signals PDS L  and PDS R . The analog audio signals PDS L  and PDS R  thus generated are selected by using the audio output selection unit  114 , and are sent to the volume adjustment unit  115  as the analog audio signals PBS L  and PBS R . 
     Hereinafter, similarly to these for the analog audio signals PAS L  and PAS R , the volume is adjusted by the volume adjustment unit  115 , and replay audio based on the result of the adjustment is output from the speakers  130   L  and  130   R  into the music space. 
     As has been explained above, in this embodiment, the resistance value of the function reporting unit  112  is switched by using actuation input to the actuation input unit  150  of the audio device  100 , and it makes possible to transfer the actuation function of the portable audio device  500  to the audio device  100  side, or return to the portable audio device  500  side, as desired. In this manner, the position where the actuation for replaying audio recorded in the portable audio device  500  is performed can be switched. Therefore, it is possible to perform replay of audio recorded in the portable audio device  500  by using the speakers of the audio device  100  in a reliable manner, by returning the position of actuation to the portable audio device  500 , even if the version of the audio device  100  and the version of the portable audio device  500  do not match one another. 
     Depending on the actuation input to the actuation input unit  150  of the audio device  100 , the permission/prohibition of the actuation by the person owns the portable audio device  500  is placed under the control of the audio device  100  side. 
     In this embodiment, when the operational state of the vehicle is on any one of the accessory ON state, the ignition ON state, and the starting state, the charging power CPW to the portable audio device  500  is supplied; however, when it is on the OFF state, the charging power CPW to the portable audio device  500  is not supplied. Due to this, the power consumption of the vehicle power supply  920  while the engine is stopped can be reduced. 
     Further, in this embodiment, as the audio to be output from the speakers  130   L  and  130   R , either the analog audio signals PAS L  and PAS R , which is output from the portable audio device  500 , or the analog audio signals PDS L  and PDS R , on which audio content recorded on the recording medium is replayed and loaded into the drive unit  120 . Due to this, through the actuation of the actuation input unit  150 , the user can freely select the audio signal to be output. 
     Consequently, according to this embodiment, cooperation between the portable audio device and the other device can be promoted, thereby promoting the convenience for the user. 
     Modified Embodiments 
     The present invention is not limited to that described above; and it may be varied in many ways. 
     For example, in the embodiment described above, it was arranged to provide two speakers, however, it would also be possible to arrange to output the sound from only one speaker, or to output the sound from three or more speakers adaptive to a multi-channel setup. 
     In the embodiment described above, as the switching element  212  in the function reporting unit  112 , it is possible to employ a switching element such as electronic type one, a transistor, and a mechanical type one, a reed relay, and the like. 
     Furthermore, in the embodiment described above, when the function reporting unit  112  changes the content reported to the portable audio device  500  by changing the resistance value seen from externally. In contrast, configuration of the function reporting unit  112  may be these that match to the decision methods for the function employed in the portable audio device, and desirable one can be employed. 
     In the embodiment described above, the present invention was applied to an audio device which was mounted to a vehicle, it would also be possible to apply the present invention to an audio device mounted to some mobile device other than a vehicle; or it would also be possible to apply the present invention to an audio device for household use. 
     Further, in the embodiment described above, the present invention was applied to an audio device for replaying audio content, it would also be possible to apply the present invention to a device for replaying a moving image along with audio content. 
     Note that a part or the entire control unit  110  in the embodiment described above may be constituted by using a computer as a calculation part, comprising a central processing device (CPU), a DSP (Digital Signal Processor), a read only memory (ROM), a random access memory (RAM), and the like; then a part or the entire of the processing may be executed by the previously prepared program. The program is recorded on the medium such as the hard disk, CD-ROM, DVD and the like, which can be read out by the computer, and it is read out by the computer to be executed. The program may be obtained as a form recorded on the portable type medium such as CD-ROM, DVD and so forth, or the form being distributed via a network such as the internet or the like.