Abstract:
A system that links a mobile device with a vehicle on-board unit includes a data control section that restricts use of at least one of a plurality of registered application software products provided on the mobile device, and a data output section that outputs an indication representing the at least one registered application software product to a display section of the vehicle on-board unit when the at least one application software product is available according to conditions of the vehicle.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a system that links a vehicle on-board unit and a mobile device. 
     BACKGROUND OF THE INVENTION 
     A system that links a mobile device with a vehicle on-board unit has been proposed as an information service system disclosed in Japanese Patent Application Laid-open Publication (JP-A) No. 2010-250376. In the information service system, a display mode to be displayed on a display part of a vehicle on-board unit is specified previously, a mobile device acquires content data and converts the acquired content data into the previously specified display mode, and the vehicle on-board unit displays the converted content data on its display part. This arrangement is advantageous in that the vehicle on-board unit does not have to have the same on-board browser as the mobile device. 
     The mobile device such as mobile phone can be used with various application software products (hereinafter referred to, for brevity, as “applications”), however, for some sort of applications, execution is not desirable while the vehicle is moving or in motion. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a system that links a vehicle on-board unit with a mobile device without hindering safe driving the vehicle. 
     According to the present invention, there is provided a vehicle on-board unit and mobile device linkage system, comprising: an on-board unit installed in a vehicle, the on-board unit having a display section; a mobile device having a plurality of application software products registered therein; a data control section that restricts use of at least one of the plurality of registered application software products; and a data output section that outputs an indication representing the at least one registered application software product to the display section of the on-board unit when the at least one registered application software product is available according to conditions of the vehicle 
     With this arrangement, since the data control section restricts use of at least one of a plurality of registered application software products, it is possible to selectively place the application software products in an available state according to conditions of the vehicle. Furthermore, since the data output section outputs an indication representing each respective available registered application software product to the display section of the vehicle on-board unit, an indication representing an unavailable registered application software product does not come into driver&#39;s attention. The driver is allowed to concentrate on continuing driving operation, which will lead to safe driving of the vehicle. 
     Preferably, the vehicle on-board unit and mobile device linkage system further comprises a vehicle travel determining section that determines as to whether the vehicle is in motion or in park, wherein the at least one registered application software product includes a first registered application software product which is available while the vehicle is in motion, and a second registered application software product which is available while the vehicle is in park, and wherein when the data output section outputs the indication of the at least one registered application software product to the display section of the on-board unit, the data output section automatically switches between a first screen on which the first registered application software product is displayed and a second screen on which the second registered application software product is displayed, based on a determination made by the vehicle travel determining section. 
     By virtue of the vehicle travel determining section, the data output section can automatically switch between the first screen and the second screen. This arrangement makes the driver freer from a laborious manual operation required to switch the screens and allows the driver to concentrate on continuing safe driving of the vehicle. 
     In one preferred form of the present invention, the vehicle travel determining section uses information from a parking brake of the vehicle in order to determine conditions of the vehicle. By thus using information from the parking brake, the vehicle travel determining section can surely determine a moving state of the vehicle. 
     Preferably, the first registered application software product which is available while the vehicle is in motion is such an application software product which is capable of recognizing a voice-activation command from a driver of the vehicle. This arrangement allows the driver to activate the first registered application software product by voice and provides a substantive reduction in driving operation loads on the driver, leading to highly safe driving of the vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One preferred structural embodiment of the present invention will be described in detail herein below, by way of example only, with reference to the accompanying sheets of drawings, in which: 
         FIG. 1  is a diagrammatical view showing a general configuration of a vehicle on-board unit and mobile device linkage system according to one embodiment of the present invention; 
         FIG. 2  is a schematic functional block diagram of the system; 
         FIG. 3A  is a diagrammatical view illustrative of the manner in which a group of applications available while the vehicle is moving or in motion is displayed; 
         FIG. 3B  is a diagrammatical view illustrative of the manner in which a group of applications available while the vehicle is stopped or in park is displayed; 
         FIG. 4  is a block diagram showing a configuration of hardware of the mobile device shown in  FIG. 1 ; and 
         FIG. 5  is a schematic functional block diagram showing functional sections that can be added to the linkage system shown in  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and  FIG. 1  in particular, there is shown a general configuration of a vehicle on-board unit and mobile device linkage system according to an embodiment of the present invention. As shown in  FIG. 1 , the system  300  generally comprises a mobile device  100  and a vehicle on-board unit  200  that can be linked with each other. More particularly, the mobile device  100  serves as a controller or master, while the vehicle on-board unit  200  serves as an external monitor or slave. The vehicle on-board unit  200  has a display section  210  that can be controlled by executing an application provided on the mobile device  100 . In the embodiment shown in  FIG. 1 , an image shown on a screen of the display section  210  of the vehicle on-board unit  200  represents an image shown on a screen of a display section  110  of the mobile device  100 . When the display section  210  is larger in size or pixel density than the display section  110 , the image shown on the screen of the display section  110  of the mobile device  100  is enlarged on the side of the display section  210 . 
     In the embodiment shown in  FIG. 1 , the mobile device  15  is a mobile phone unit (so-called “smartphone”, for example) which is linkable with the vehicle on-board unit  200 . The mobile device (mobile phone unit)  100  can communicate with a mobile telephone network (and Internet) via a base station  50 , for example. The mobile device  100  does not have to be connectable with the mobile telephone network and may include a portable tablet personal computer, a personal digital assistant (PDA) and another type of portable personal computer. The vehicle on-board unit  200  may include a monitor unit, audio unit, navigation unit and the like. The vehicle on-board unit  200  is installed in a vehicle such as automobile (not shown) and has a display section  210 . While the vehicle on-board unit  200  and the mobile device  100  are linked together, the display section  210  of the vehicle on-board unit  200  serves as an external monitor of the mobile device  100 . 
       FIG. 2  shows in functional block diagram the general configuration of the system  300 . As shown in this figure, the system  300  comprises a data control section  310  and a data output section  320 . The system  300  may further include a vehicle travel determining section  330 . Though not shown in  FIG. 2 , the system  300  may further include another functional section to achieve any desired function where appropriate. 
     In case where the mobile device  100  has a plurality of applications running on an operating system (OS) such as Android, the data control section  310  shown in  FIG. 2  can restrict use of some of the plurality of applications. More particularly, the data control section  310  is able to separate and register the plurality of applications depending on their availability while the vehicle is moving or in motion. Especially, the data control section can determine whether or not each individual application corresponds to a predetermined recommended application. With this determination, only those applications, which are determined as corresponding to the predetermined recommended application (and classified in a first group of applications), are registered as non-restricted registered applications that are available while the vehicle is moving or in motion. Other applications, which are determined as not corresponding to the predetermined recommended application (and classified in a second group of applications), are registered as restricted registered applications that are available while the vehicle is in park. 
     For instance when vehicle is moving or in motion (first case), the data output section  320  shown in  FIG. 2  is allowed to output a representation of each one of the non-restricted applications (first group of applications) to the display section  210  of the vehicle on-board unit  200  shown in  FIG. 2 . At the same time, the data output section  320  does not output a representation of any one of the restricted applications (second group of applications) to the display section  210  of the vehicle on-board unit  200 . 
     The data output section  320  makes the second group of applications unavailable in the first case where the vehicle is actually moving or in motion. Alternatively, the data output section  320  makes the second group of applications available in a second case where the vehicle is actually stopped or in park. In the first case, since the data output section  320  outputs only the representations of the first group of applications to the display section  210  of the vehicle on-board unit  200 , it does never occur that the representatives of the second group of applications come into driver&#39;s attention. Thus, the driver is allowed to concentrate continued driving operation, which will lead to safe driving of the vehicle. Alternatively, in the second case, the data output section  320  outputs the representatives of the second group of applications to the display unit  210  of the vehicle on-board unit  200 , thereby allowing the driver to look at the representatives of the second group of applications on the display section  210  while the vehicle is stopped or in park. In other words, when the safety of the vehicle is assured, the driver is allowed to use the second group of applications. 
     The vehicle travel determining section  330  determines as to whether or not the vehicle is moving or in motion, by using, for example, information from a parking brake of the vehicle. More particularly, a parking brake sensor  400  is configured to detect activation and deactivation of the parking brake and generate a signal corresponding to the detected activation or deactivation of the parking brake. For instance, when a detection signal from the parking brake sensor  400  is a low-level signal, the vehicle travel determining section  330  determines that the vehicle is moving or in motion. Alternatively, when a detection signal from the parking brake sensor  400  is a high-level signal, the vehicle state determining section  330  determines that the vehicle is not moving or the vehicle is in park. The parking brake is activated, for example, when a parking brake lever is manually pulled by a driver&#39;s hand, or alternatively when a parking brake pedal is depressed by a driver&#39;s foot. The parking brake is normally disposed in a deactivated state. 
       FIG. 3A  diagrammatically illustrates the manner in which a group of applications available while the vehicle is moving or in motion is displayed, and  FIG. 3B  diagrammatically illustrates the manner in which a group of applications available while the vehicle is stopped or in park is displayed. In the example shown in  FIG. 3A , while the vehicle on-board unit  200  and the mobile device  100  are linked together, from among a plurality of applications provided on the mobile device  100 , a cooperative application (or a tab launcher application) has been executed to control the display sections  110  and  210 . The display section  110  of the mobile device  100  shows on its screen an A-tab (first tab)  120 , a B-tab (second tab)  130 , a C-tab (third tab)  140 , and a plurality of registered applications  121 ,  122 ,  123 ,  124  and  125  which has been registered on the A-tab  120 . The A-tab (first tab)  120  is a specific tab which is available when the vehicle is moving or in motion. The B-tab (second tab)  130  is a specific tab which is available when the vehicle is stopped or in park. The C-tab (third tab)  140  is an additional tab which is available when the vehicle is stopped or in park. 
     The tab launcher application transmits a video signal representing a screen of the display section  110  to the vehicle on-board unit  200  through SPP (Serial Port Profile) for Bluetooth communication (“Bluetooth” is a trademark for a wireless technology), so that the display section  210  of the vehicle on-board unit  200  can serve as an external monitor of the mobile device  100 . The screen of the display section  110  is zoomed up or enlarged and forms another or external screen of the display section  210 . The display section  210  also shows on its screen an A-tab  220 , a B-tab  230 , a C-tab  240  and a plurality of registered applications  221 ,  222 ,  223 ,  224  and  225 , which has been registered on the A-tab  220 . 
     In the illustrated embodiment, the display section  110  and the display section  210  are touch panels. While the vehicle is actually moving or in motion, the tab launcher application allows the driver to select only the A-tab  120  or  220  (specific tabs available while the vehicle is in motion) so that only those icons of the registered applications  121 - 125  and  221 - 225  which are shown in  FIG. 3A  can be displayed. The tab launcher application can receive manual input operation of one or both of the touch panel display sections  110 ,  210  via Bluetooth HID (Human Interface Device Profile) to thereby realize UMI (User-Machine Interface) control. 
     Even when the driver manually selects the B-tab  130  or  230  (which is a specific tab available while the vehicle is stopped or in park) while the vehicle is actually moving, the tab launcher application does not allow the display units  110 ,  210  to display icons of those registered applications  131 - 134  and  231 - 233  which are shown in  FIG. 3B . Alternatively while the vehicle is actually stopped or in park, the tab launcher application allows the driver to select with its finger the B-tab  130  or  230  so that the icons of the registered applications  131 - 134  and  231 - 233  are displayed on the display units  110  and  210 , respectively. While the vehicle is stopped or in park, the tab launcher application allows the driver to selectively choose with its finger all of the tabs  120 ,  130  and  140 . 
     It is desirable that while the vehicle is moving or in motion, the tab launcher application automatically selects only the A-tab  120 . In other words, it is desirable that when the vehicle changes from a stopped or parked state to a moving state, the tab launcher application automatically switches from, for example, the B-tab  130  to the A-tab  120 . With this arrangement, the driver is freed from manual operation required for switching the B-tab  130  to the A-tab  120 . Thus, by automatically determining whether the vehicle is in motion or in park, it is possible to reduce operational loads on the driver. In case where the A-tab  120  is already selected while the vehicle is in park, the tab launcher application may continue to keep the selection of the A-tab  120 . 
     The registered applications  121 - 125  fall under predetermined recommended applications and are available while the vehicle is moving or in motion. The tab launcher application allows the registered applications  121 - 125  to be registered on the A-tab  120  (which is available while the vehicle is in motion). In the example shown in  FIG. 3A , the registered application  121  is a navigation application which guides the vehicle into a desired destination; the registered application  122  is a traffic information application which provides traffic information including traffic jam-up information; the registered application  123  is a search application which searches information about the desired destination; the registered application  124  is a map application which provides map information; and the registered application  125  is a telephone application which can communicate with a mobile phone network. The registered applications to be registered on the A-tab  120  are also displayed on the display section  210  or in the A-tab  220  of the display section  210 . 
     For example, when the driver selects with its finger the navigation application  121 , the navigation application  121  is executed. During running of the navigation application, the display section  110  of the mobile device  100  is directly controlled by the navigation application, while the display section  210  of the vehicle on-board unit  200  is controlled indirectly, for example, by SPP for Bluetooth communication. The navigation application can receive a destination via Bluetooth HID (Human Interface Device Profile) and also can transmit or output a stereo audio signal to the vehicle on-board unit  200  or a speaker connected to the vehicle on-board unit  200  through A2DP (Advanced Audio Distribution Profile) for Bluetooth communication. 
     When the driver selects with its finger the telephone application, the selected telephone application is executed. During running of the telephone application, the display section  110  is directly controlled by the telephone application, while the display section  210  is controlled indirectly via SPP of Bluetooth communication. The telephone application can receive or input a voice signal from the driver via the vehicle on-board unit  200  or a microphone connected to the vehicle on-board unit  200  through Bluetooth HFP (Hands-Free Profile) and also can transmit or output a voice signal from a caller to the on-board unit  200  or the speaker connected to the on-board unit  200  via Bluetooth HFP. The mobile device  100  may be connected with the vehicle on-board unit  200  via USB (Universal Serial Bus) connection in which instance the mobile device  100  can receive electric power from the on-board unit  200  or a battery connected to the vehicle on-board unit  200 . 
     Preferably, the tab launcher application and the registered applications  121 - 125  are applications which can recognize voice action commands issued from the driver. In this case, the driver is allowed to operate the registered applications  121 - 125  by voice while the vehicle is moving so that operation loads on the driver can be reduced. It is also preferable that the registered applications  131 - 134  can recognize voice action commands issued from the driver. 
     The registered applications  131 - 134  do not fall under predetermined recommended applications and are available while the vehicle is stopped or in park. The tab launcher application allows the registered applications to be registered on, for example, the B-tab  130  (which is available while the vehicle is stopped or in park). The mobile device  100  has a capacity to contain many applications and this will allow the driver to sort the registered applications to be registered on the B-tab  130 . The C-tab  140  accepts registration of other recorded applications that are available while the vehicle is stopped or in park. In the example shown in  FIG. 3B , the registered application  131  is a motion picture application that can play videos on the Internet; the registered application  132  is a TV application that enables TV reception; the registered application  133  is a music application that can replay promotion videos on the mobile device  100 ; and the registered application  134  is a photo application that can replay picture images like a slide show. The registered applications  131 - 134  registered on the B-tab  130  are also displayed on the display section  210  or the B-tab  230  of the display section  210 . 
     When the driver selects the TV application  132  with its finger, the selected TV application is executed. While the TV application  132  is running, the display section  110  is directly controlled by the TV application  132 , while the display section  210  is indirectly controlled via WiFi (Wireless fidelity), for example. The TV application  132  can receive a desired channel via Bluetooth HID and transmit or output a stereo audio signal to the vehicle on-board unit  200  or the speaker connected to the vehicle on-board unit  200  through A2DP for Bluetooth communication. When a telephone call is received while the TV application is running, the telephone application may be preferentially executed. The telephone application allows the driver to hands-free communicate with a caller via HFP for Bluetooth communication. 
       FIG. 4  is a block diagram showing a configuration of hardware of the mobile device  100  shown in  FIG. 1 . The vehicle on-board unit  200  shown in  FIG. 1  may have the same hardware configuration. The mobile device  100  includes a storage unit, such as a hard disk drive (HDD), flash memory and the like, which can store an OS application and a plurality of applications capable of running on the OS application. The plurality of applications includes the aforesaid tab launcher application and those applications  121 - 125  and  131 - 135  which can be registered in the tab launcher application. The applications thus stored in the storage unit can be executed by a processing unit such as a CPU (central processing unit) of a microcomputer. When the tab launcher application is executed, the processing unit of the mobile device  100  operates as the data control section  310  and the data output section  320  shown in  FIG. 2 . 
     As shown in  FIG. 4 , the mobile device  100  further includes an input unit and a display unit. The input unit and the display unit may be formed by a single touch screen display panel module. The mobile device  100  also includes a communication unit, which may be formed by a 3 G communication module, a Bluetooth communication module, or a WiFi communication module. The mobile device  100  further includes an I/O or interface unit, which may be formed by a USB interface module. 
     The vehicle on-board unit  200  includes a storage unit such a HDD, flash memory and the like. The storage unit is able to store an OS application and at least one application capable of running on the OS application. The storage unit of the vehicle on-board unit  200  can also store information about any one of the predetermined recommended applications. The at least one application includes a linkage recognition application that can recognize completion of a linkage between the vehicle on-board unit  200  and the mobile device  100 . The linkage recognition application receives a video signal from the mobile device  100  and executes linkage or cooperation with the mobile device  100  on condition that the tab launcher application is in an execution status. 
     The linkage recognition application can transmit information about any of the predetermined recommended applications to the tab launcher application. The linkage recognition application also can update or renew the information about the predetermined recommended applications. The tab launcher application classifies and registers a plurality of applications into corresponding ones of the tabs  120 ,  130  and  140  based on the information received from the linkage recognition application and information about the predetermined recommended applications stored in the storage unit of the mobile device  100 . 
     The storage unit of the vehicle on-board unit  200  may further store a vehicle travel determination application. The vehicle travel determination application is configured to determine whether or not the vehicle is actually moving or in motion and transmit a determination result to the tab launcher application. Based on the transmitted determination result, the tab launcher application selects a desired tab from among tabs  120 ,  130  and  140  or switches to a desired tab. These and other applications can be executed by a processing unit such as a CPU of the vehicle on-board unit  200 . For example, when the vehicle travel determining application is executed, the processing unit of the vehicle on-board unit  200  operates as the vehicle travel determining section  330  shown in  FIG. 2 . 
     The vehicle on-board unit  200  further includes an input unit and a display unit. The input unit and the display unit may be formed by a single touch screen display panel module. The vehicle on-board unit  200  also includes a communication unit, which may be formed by a Bluetooth communication module or a WiFi communication module. The vehicle on-board unit  200  further includes an I/O or interface unit, which may be formed by a USB interface module, a speaker interface module, a microphone interface module, and a parking brake sensor module. The vehicle on-board unit  200  is configured to communicate with a vehicle on-board network such as CAN (Controller Area Network). 
     As previously described, when the tab launcher application is executed, the processing unit of the mobile device  100  operates as the data control section  310  and the data output section  320  both shown in  FIG. 2 . When the linkage recognition application is executed, the processing unit of the vehicle on-board unit  200  may operate as a part of the data control section  310  and a part of the data output section  320 . Furthermore, when the vehicle travel determining application is executed, the processing unit of the on-board unit  200  operates as the vehicle travel determining section  330  shown in  FIG. 2 . Additionally, upon execution of the tab launcher application, the processing unit of the mobile device  100  may operate as a part of the vehicle travel determining section  330 . 
       FIG. 5  schematically shows in functional block diagram a contents transfer system according to the present invention. The system shown in FIG.  2  may further equipped with the configuration shown in  FIG. 5 . Content player applications including the motion picture application  131 , TV application  132 , music application  133  and photo application  134  can transmit a video signal representing a screen of the display section  110  to the vehicle on-board unit  200  via Bluetooth or WiFi. Other applications than the content player applications can also transmit a video signal via Bluetooth or WiFi. 
     In the example shown in  FIG. 5 , the system  300  includes an image data reading section  340 , a transfer mode selecting section  350 , a data processing section (first data processing section)  360 , a transfer section  370 , and a data processing section (second data processing section)  380 . 
     The mobile device  100  shown in  FIG. 1  can communicate with the Internet via the mobile phone network and downloads or streaming moving image file content data or still image file content data on the Internet. 
     The image data reading section (content data reading section)  340  shown in  FIG. 5  reads a file type or format (file extension, for example) of the downloaded or streamed content data to determine the type of the content data. 
     Additionally or alternatively, the image data reading section  340  may read a bit rate of the content data so that the type of the content data obtained by the mobile device  100  through downloading or streaming can be determined. Thus, in order to determine the type of content data, the image data reading section (content data reading section)  340  may selectively read only the file format of the content data, only the bit rate of the content data, or both the file format and the bit rate of the content data. 
     In the case where content data downloaded or streamed by the mobile device  100  has a moving image file type or format, the image data reading section  340  is allowed to read a bit rate of the moving image file content data to determine the type of the content data. 
     The transfer mode electing section  350  shown in  FIG. 5  selects one of two transfer modes based on the result of determination by the image data reading section (content data reading section)  340 . If the file format of the content data is a still image file format, the transfer mode selecting section  350  will select a Bluetooth transfer mode rather than a WiFi transfer mode because Bluetooth uses a radio technology called frequency-popping spread spectrum. By thus selecting the transfer mode using the frequency-popping spread spectrum, the transfer mode selecting section  350  can transfer the still image file type content data through a stable channel without deterioration of the data transfer rate. Alternatively, if the file format of the content data is a moving image file type or format, the transfer mode selecting section  350  will select the WiFi transfer mode in which a LAN (Local Area Network) connection is used. By thus selecting the WiFi transfer mode using the LAN connection, the transfer mode selecting section  350  can achieve high-speed transfer of the moving image file type content data. 
     When content data has a bit rate less than a predetermined bit rate regardless of the file type or format, or alternatively when content data has a moving image file format and the moving image file type content data has a bit rate less than the predetermined bit rate, the transfer mode selecting section  350  may select the Bluetooth transfer mode rather than the WiFi transfer mode. On the other hands, when content data has a bit rate greater than the predetermined bit rate regardless of the file type or format, or alternatively when content data has a moving image file format and the moving image file type content data has a bit rate greater than the predetermined bit rate, the transfer mode selecting section  350  may select the WiFi transfer mode rather than the Bluetooth transfer mode. 
     The transfer section  370  shown in  FIG. 5  may bypass the data processing section  360  and transfer the image data (content data) from the mobile device  100  directly to the on-board unit  200 . It is preferable, however, that the image data (content data) is temporarily stored and or compressed by the data processing section  360  before transmission. In both transfer modes (i.e., the Bluetooth transfer mode and the WiFi transfer mode), the actual transfer rate fluctuates by the effect of radio waves. Rather than continuing transmission of the image data (content data) at a constant speed, it is preferable that the image data (content data) is temporarily stored and transmitted while an actual transfer rate is taken into consideration. Furthermore, the image data (content data) is preferably compressed before transmission. By thus processing the image data (content data) by the data processing section  360 , highly efficient transfer of the image data (content data) can be achieved. 
     In case where the image data (content data) has been subjected to compression by the data processing section  360 , the data processing section (second data processing section)  380  decompresses the compressed image data (compressed content data) after the compressed image data (compressed content data) is transferred. 
     In case where the content data has a still image Me type or format, the content player application transmits a video signal forming a screen of the display section  110  to the vehicle on-board unit  200  via SPP of Bluetooth communication, so that the display section  210  can operate as an external monitor. Alternatively, when the content data has a moving image file type or format, it is difficult for the content player application to transfer such moving image file type content data at a relatively low transfer rate as occurring in Bluetooth communication. To avoid this problem, the motion picture application  131  transmits a video signal forming an image on the display section  110  to the vehicle on-board unit  200  via WiFi so that the display section  210  can operate as an external monitor. In case where the motion picture application  131  and/or the other application (content player application) is used to play content data having a bit rate greater than the predetermined bit rate, the content data may be transmitted as a video signal to the vehicle on-board unit  200  via WiFi. 
     When the moving image application or the like content player application accesses content data having a moving image file format (and/or content data having a bit rate greater than the predetermined bit rate) through the mobile phone network (and the Internet), these content datum including the moving image file type content data can be placed in a playable state after they are downloaded. Stated more specifically, the moving image application or the like content player application suspends or interrupts running of the content data until downloading is completed. During a time when content data having a moving image file format (and/or content data having a bit rate greater than the predetermined bit rate) is downloaded, operation on the touch panel display sections  110  and  210  is disabled. This means that even when a play button is selected by the driver&#39;s finger, play of the content data having a moving image file format (and/or the content data having a bit rate greater than the predetermined bit rate) does never occur. When the play button is selected after the downloading of the foregoing content data is completed, the moving image application or the like content player application switches the type of communication from Bluetooth SPP to WiFi and transmits a video signal representing a screen of the display section  110  to the vehicle on-board unit  200  at a high speed via WiFi so that the display section  210  of the vehicle on-board unit  200  can operate as an external monitor. 
     Switching from Bluetooth to WiFi made for playing content data after completion of the downloading is particularly advantageous when the vehicle on-board unit  200  and the mobile device  100  are linkable together via WiFi using a LAN communication and when the mobile device  100  cannot continue connection with the mobile phone network due to a so-called “tethering restriction” provided under the telecom regulations. Conventionally, the transfer mode which is available while a linkage is completed between a vehicle on-board unit and a mobile device is fixed to Bluetooth or WiFi, such as described at paragraph [0013] of Japanese Patent Application Laid-open Publication (JP-A) No. 2010-199718. 
     When the moving image application or the like content player application is executed, the processing unit of the mobile device  100  operates as the image data reading section  340 , transfer mode selecting section  350 , data processing section  360  and transfer section  370  shown in  FIG. 5 . However, since the linkage recognition application is executed, an arrangement is possible in which the processing unit of the vehicle on-board unit  210  operates as a part of the image data reading section  340 , a part of the transfer mode selecting section  350 , a part of the data processing section  360 , and a part of the transfer section  370 . The moving image application  131  of the mobile device  100  may be configured to cooperate with the linkage recognition application of the vehicle on-board unit  200  and/or the tab launcher application of the mobile device  100 . When the linkage recognition application is running, the processing unit of the vehicle on-board unit  200  can operate as the data processing section  380  shown in  FIG. 5 . However, by executing the moving image application and/or the tab launcher application, an arrangement is also possible in which the processing unit of the mobile device  100  operates as a part of the data processing unit  380 . 
     The linkage made between the vehicle on-board unit  200  and the mobile device  100  may be a wireless linkage using a protocol such as Bluetooth or Wifi, or alternately a wired linkage. Furthermore, the vehicle on-board unit  200  and the mobile device  100  may be linked together via a relaying apparatus (not shown), in which instance the vehicle on-board unit  200  and the relaying apparatus may be linked by wire, and the relaying apparatus and the mobile device  100  may be wirelessly linked together. 
     Furthermore, when an image displayed on the display section  110  of the mobile device  100  is also displayed on the display section  210  of the vehicle on-board unit  200 , the OS application of the vehicle on-board unit  200  and any of the applications capable of running on this OS application may operate as a client side of VNC (Virtual Network Computing), while the OS application of the mobile device  100  and any of the applications capable of running on this OS application may operate as a server side of VNC. 
     Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.