Abstract:
A charge monitoring apparatus is mountable on or connectable to a vehicle which uses electrical power supplied from a battery on the vehicle for traveling. The charge monitoring apparatus includes a vehicle ID holding portion that holds vehicle-side identification information which is uniquely allocated to each specific vehicle, a power-line communicating portion that performs a power line communication with an extravehicular apparatus through a power supply line which supplies the electric power from the external power supply equipment to the battery, a vehicle-side information storing portion that stores information produced in the vehicle, and a communication controlling portion that, in the power line communication, transmits the vehicle-side identification information held in the vehicle ID holding portion to the extravehicular apparatus, and if predetermined condition is satisfied, the communication controlling portion transmits the information stored in the vehicle-side information storing portion to the extravehicular apparatus.

Description:
BACKGROUND 
       [0001]    The present invention relates to a charge monitoring apparatus for monitoring an operation of charging a battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle. 
         [0002]    In the automobile industry, recently, an electric vehicle which travels by using only electricity as energy, and a hybrid vehicle on which both an engine and an electric motor are mounted are practically used from the standpoints of carbon dioxide emission reduction and efficient use of energy. In a usual hybrid vehicle, kinetic energy generated when the vehicle is decelerated is recovered while being converted to electric energy, and then charged into a battery, and the recovered electric energy is used in traveling to suppress consumption of a fuel such as gasoline. In the case where only the recovery of kinetic energy generated when a vehicle is decelerated is used, however, the effect of reducing the fuel consumption is small, and also the effect of reducing carbon dioxide is small. 
         [0003]    In order to enhance the effect of reducing carbon dioxide, therefore, a plug-in hybrid vehicle (plug-in HV) has been developed. A plug-in hybrid vehicle has a function that a plug disposed on the vehicle is inserted into a domestic power supply socket or the like and a battery of the vehicle is charged by a domestic power supply (commercial AC power supply: AC 100 V or the like). In addition to kinetic energy which can be recovered when the vehicle is decelerated, therefore, also electric energy which is obtained from the domestic power supply by charging can be used in travel of the vehicle. Consequently, the use frequency of the electric motor can be enhanced to suppress the fuel consumption, and the electric motor which has a high efficiency can be used highly frequently to enhance the effect of reduction of carbon dioxide. 
         [0004]    On the other hand, in order to enhance the effect of reducing carbon dioxide which is discharged in relation to a vehicle, also an economical driving operation is very effective. When a driving operation accompanied by large fuel consumption in a short time period, such as a case where sudden acceleration is performed during driving of a vehicle is eliminated, for example, the fuel consumption can be suppressed, and the effect of reducing carbon dioxide can be enhanced. 
         [0005]    As a technique available for enabling the driver of a vehicle to perform an economical driving operation, conventionally, a tachograph and a navigation apparatus have been put into practical application and used. 
         [0006]    A tachograph periodically obtains information indicating the driving situation of a vehicle, such as the vehicle speed and the number of revolutions of the engine, and records the information as time series information. A business such as a taxi company or a trucking company refers to and analyzes the time series information recorded by the tachograph, so that it is possible to know whether the driver of the vehicle performs an economical driving operation or not. This can be used for enhancing the effect of reducing carbon dioxide. 
         [0007]    A navigation apparatus can perform the following operations: the current position of a vehicle on which the apparatus is mounted is measured, and map information related to the vicinity of the current position is displayed on a screen; a possible travelling route from the current position to the destination is automatically determined; and latest traffic information such as information indicating the traffic jam situation, or the accident occurrence situation is obtained, and the information is reflected into a change of the possible travelling route. When a navigation apparatus is used, for example, it is possible to determine the possible travelling route so that the vehicle travels through the shortest route, or change the possible travelling route so that the route avoids a jammed location or a location of an accident. Therefore, this can be used for enhancing the effect of reducing carbon dioxide. 
         [0008]    In an actual use of a tachograph, in order to enable an administrator in a taxi company, a trucking company, or the like to know the travelling situations of vehicles, however, a large amount of information stored in tachographs mounted on the vehicles must be retrieved from the tachographs, and then transferred to an apparatus (for example, a personal computer) on the side of the administrator. 
         [0009]    For example, Patent Reference 1 discloses a conventional technique for transferring information from a tachograph which is a vehicle-mounted apparatus to an apparatus on the side of the administrator. Patent Reference 1 proposes information transfer in which a wireless communication interface that can perform packet communication is used, or a detachable memory card is used. 
         [0010]    By contrast, in the case where a navigation apparatus is used, for example, latest map information or the like is always necessary in order to determine an optimum possible travelling route. When, although a new road which can avoid a jammed location included in a possible travelling route has been completed, old map information in which information of the new road is not reflected is used, for example, it is impossible to avoid the jammed location, and hence the effect of reducing carbon dioxide cannot be sufficiently enhanced. 
         [0011]    In the case where a navigation apparatus for a vehicle is used, conventionally, map information or the like that is used in the navigation apparatus which is a vehicle-mounted apparatus is usually updated to latest information by using a detachable information recording medium such as a CD (Compact Disc) or a DVD, or by using mobile packet communication. In the conventional technique disclosed in Patent Reference 2, when map data are to be updated, for example, the use of differential data is enabled in order to reduce the amount of data to be transferred by communication. 
         [0012]    [Patent Reference 1] JP-A-2008-108235 
         [0013]    [Patent Reference 2] JP-A-2008-249624 
         [0014]    In the case where a public wireless communication network is used in the data transfer from a tachograph which is a vehicle-mounted apparatus to an extravehicular administrating apparatus, however, there is a problem in that, when the data amount is increased, the communication cost such as the packet communication fee is raised, and another problem of security arises. In the case where data are transferred by using a detachable recording medium such as a memory card, there is a possibility that leakage of information to a third party may be caused by a loss of the memory card, or that accumulated important data may be lost by physical breakage of the memory card. 
         [0015]    Also in the case where a navigation apparatus is used, similarly, there is a problem in that, when a public wireless communication network is used in update of a database such as a map used in the apparatus to latest information, the communication cost is raised. In the case where the database is to be updated by using a detachable information recording medium such as a CD or a DVD, a reading apparatus (such as a DVD drive) for reading data from such a dedicated information recording medium is necessary, and there is a possibility that the information recording medium may be physically broken. 
       SUMMARY 
       [0016]    The invention has been conducted in view of the above-discussed situation. It is an object of the invention to provide a charge monitoring apparatus in which, in the case where the function of a tachograph or a navigation apparatus is used in an electric vehicle or plug-in hybrid vehicle that is chargeable, the burden such as a communication cost due to information transfer, or the like can be reduced. 
         [0017]    In order to achieve the above object, according to the present invention, there is provided a charge monitoring apparatus that is mountable on or connectable to a vehicle which uses electrical power supplied from a battery on the vehicle for traveling, the charge monitoring apparatus monitoring a supply of the electrical power to the battery from an external power supply equipment which is disposed separately from the vehicle, the charge monitoring apparatus, comprising: 
         [0018]    a vehicle ID holding portion that holds vehicle-side identification information which is uniquely allocated to each specific vehicle; 
         [0019]    a power-line communicating portion that performs a power line communication with an extravehicular apparatus through a power supply line which supplies the electric power from the external power supply equipment to the battery, the extravehicular apparatus connected to the external power supply equipment; 
         [0020]    a vehicle-side information storing portion that stores information produced in the vehicle; and 
         [0021]    a communication controlling portion that, in the power line communication, transmits the vehicle-side identification information held in the vehicle ID holding portion to the extravehicular apparatus, and if predetermined condition is satisfied, the communication controlling portion transmits the information stored in the vehicle-side information storing portion to the extravehicular apparatus. 
         [0022]    Preferably, the information stored in the vehicle-side information storing portion includes a vehicle speed and a number of revolutions of an engine of the vehicle. 
         [0023]    Preferably, the information stored in the vehicle-side information storing portion includes at least one of traffic information and history information of traveling route of the vehicle. 
         [0024]    Preferably, the charge monitoring apparatus includes an information update controlling portion that, in the power line communication, receives information sent from the extravehicular apparatus via the power-line communicating portion, and updates a content of the information stored in the vehicle-side information storing portion, by using the received information. 
         [0025]    Preferably, in the power line communication, the communication controlling portion receives connection destination identification information indicating the extravehicular apparatus from the extravehicular apparatus via the power supply line, and compares the connection destination identification information with pre-registered information preliminary registered in the vehicle, and only in a case of coincidence between the connection destination identification information and the pre-registered information, the communication controlling portion transmits information stored in the vehicle-side information storing portion to the extravehicular apparatus. 
         [0026]    According to the present invention, there is also provided a charge monitoring apparatus that is connectable through a power supply line to a vehicle which uses electrical power supplied from a battery on the vehicle for traveling, the charge monitoring apparatus being connected to an external power supply equipment which is disposed separately from the vehicle, in order to monitor a supply of the electrical power from the external power supply equipment to the battery, the charge monitoring apparatus, comprising: 
         [0027]    a power supply ID holding portion that holds power supply-side identification information which is uniquely allocated to a specific external power supply equipment; 
         [0028]    a power-line communicating portion that performs a power line communication with a communication portion on the vehicle through a power supply line which supplies the electric power from the external power supply equipment to the battery; and 
         [0029]    a power supply-side reception controlling portion that, in the power line communication, transmits the power supply-side identification information held in the power supply ID holding portion to the vehicle, receives information transmitted from the vehicle via the power supply line, and stores the received information in a power supply-side storing portion. 
         [0030]    Preferably, the charge monitoring apparatus further includes a map information holding portion that successively obtains latest map information, and a power supply-side transmission controlling portion that, in the power line communication, transmits the latest map information held in the map information holding portion to the vehicle via the power supply line. 
         [0031]    According to the charge monitoring apparatus, when the vehicle and the external power supply equipment are connected to each other and the battery on the vehicle is charged by using the electrical power supplied from the external power supply equipment (in the power line communication), the information stored in the vehicle-side information storing portion can be transmitted under the control of the communication controlling portion to the extravehicular apparatus. Namely, information can be transferred from the vehicle to the external power supply equipment while using the power supply line which, in order to charge the battery, connects the external power supply equipment to the vehicle, as a signal transmission line. Therefore, it is not required to use a public wireless communication network, and to use a detachable information recording medium such as a memory card. Consequently, the communication cost can be reduced, a security problem such as leakage of information can be solved, and a loss of stored information due to physical breakage of an information recording medium can be prevented from occurring. When a charging operation is to be performed, moreover, the vehicle-side identification information held in the vehicle ID holding portion is transmitted to the extravehicular apparatus. Therefore, the external power supply equipment can identify the connected vehicle, so that an unauthorized charging operation and the like can be prevented from being performed, and the transmission source can be identified. 
         [0032]    According to the charge monitoring apparatus, information indicating the driving situation of the vehicle and stored in a tachograph mounted on the vehicle, such as the vehicle speed and the number of revolutions of the engine can be transferred to the external power supply equipment through the power supply line. 
         [0033]    According to the charge monitoring apparatus, information stored in the navigation apparatus mounted on the vehicle, such as traffic information which is obtained by the navigation apparatus from facilities on the road and the like, and the history of the traveling route can be transferred to the side of the external power supply equipment through the power supply line. 
         [0034]    According to the charge monitoring apparatus, the information update controlling portion can receive information sent from the extravehicular apparatus disposed on the external power supply equipment, via the power-line communicating portion, and, by using the received information, update the content of the information such as a map which is used by the navigation apparatus, to latest information, or update programs of the tachograph. 
         [0035]    According to the charge monitoring apparatus, by the connection destination identification information received by the communication controlling portion, the external power supply equipment is identified on the vehicle, and it is checked whether the equipment coincides with that which is previously registered in the vehicle, or not. Therefore, it is possible to distinguish a situation where there is no fear of information leakage to a third party, such as the case where the apparatus is connected to the external power supply equipment via a power supply socket in the home of the owner of the vehicle, or that where the apparatus is connected to the external power supply equipment via a power supply socket in a company of a specific business, from that where security against information leakage cannot be ensured as in a public external power supply equipment. Consequently, the problem of security of information to be transferred can be solved. 
         [0036]    According to the charge monitoring apparatus, when the vehicle and the external power supply equipment are connected to each other and the battery on the vehicle is charged by using the electrical power supplied from the external power supply equipment, the external power supply equipment can receive information transmitted from the vehicle through the power supply line. When information stored in a tachograph or navigation apparatus on the vehicle is to be transferred to an administrating apparatus which is outside the vehicle, therefore, it is not required to use a public wireless communication network, or to use a detachable information recording medium such as a memory card. Therefore, the cost of communication can be reduced; the problem of security such as leakage of information can be solved, and the stored information can be prevented from being destroyed by physical breakage of the information recording medium. When a charging operation is to be performed, moreover, the power supply-side identification information held in the power supply ID holding portion is transmitted to the vehicle. Therefore, the vehicle can identify the external power supply equipment of the connection destination, and the transmission destination of information can be restricted to a specific external power supply equipment which is secure. 
         [0037]    According to the charge monitoring apparatus, the power supply-side transmission controlling portion which is disposed on the external power supply equipment transmits latest information held in the map information holding portion to the vehicle via the power-line communicating portion. In the vehicle side, by using the received information, therefore, the contents of a database such as a map which is used by, for example, the navigation apparatus can be updated to latest information. 
         [0038]    When the charge monitoring apparatus of the invention is used, the burden such as a communication cost due to information transfer, or the like can be reduced in the case where the function of a tachograph or a navigation apparatus is used in an electric vehicle or plug-in hybrid vehicle that is chargeable. Namely, information is transferred by wire through the power supply line which, when a charging operation is to be performed, connects the vehicle to the external power supply equipment. Therefore, it is not required to use a public wireless communication network, and to use a detachable information recording medium such as a memory card. Consequently, the communication cost can be reduced, a security problem such as leakage of information can be solved, and a loss of accumulated information due to physical breakage of an information recording medium can be prevented from occurring. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein: 
           [0040]      FIG. 1  is a block diagram showing a configuration example of a plug-in hybrid vehicle and a power supply equipment which is used in a charging operation in an embodiment; 
           [0041]      FIG. 2  is a block diagram showing the configuration of a PLC unit shown in  FIG. 1 ; 
           [0042]      FIG. 3  is a flowchart showing the contents of the control of a PLC unit disposed on the side of the plug-in hybrid vehicle shown in  FIG. 1 ; 
           [0043]      FIG. 4  is a flowchart showing the contents of the control of a power-supply side charge monitoring apparatus disposed on the side of the power supply equipment shown in  FIG. 1 ; 
           [0044]      FIG. 5  is a flowchart showing a modification of the contents of the control of the PLC unit shown in  FIG. 3 ; 
           [0045]      FIG. 6  is a flowchart showing a modification of the contents of the control of the power-supply side charge monitoring apparatus shown in  FIG. 4 ; 
           [0046]      FIG. 7  is a view showing a configuration example of information held in a charging history holding portion  27  on a side of a power supply equipment; 
           [0047]      FIG. 8  is a view showing a configuration example of information held in a charging history holding portion of the PLC unit disposed on the side of the plug-in hybrid vehicle; and 
           [0048]      FIG. 9  is a time chart showing a configuration example of a signal transmitted through a charging electrical cable. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0049]    A specific embodiment of the charge monitoring apparatus of the invention will be described with reference to  FIGS. 1 to 6 . 
         [0050]      FIG. 1  is a block diagram showing a configuration example of a plug-in hybrid vehicle and a power supply equipment which is used in a charging operation in the embodiment,  FIG. 2  is a block diagram showing the configuration of a PLC unit shown in  FIG. 1 ,  FIG. 3  is a flowchart showing the contents of the control of the PLC unit disposed on the side of the plug-in hybrid vehicle shown in  FIG. 1 ,  FIG. 4  is a flowchart showing the contents of the control of a power-supply side charge monitoring apparatus disposed on the side of the power supply equipment shown in  FIG. 1 ,  FIG. 5  is a flowchart showing a modification of the contents of the control of the PLC unit shown in  FIG. 3 , and  FIG. 6  is a flowchart showing a modification of the contents of the control of the power-supply side charge monitoring apparatus shown in  FIG. 4 . 
         [0051]    In the embodiment, the case will be considered where, as shown in  FIG. 1 , the plug-in hybrid vehicle (HV)  10  is connected to the power supply equipment  20  through a charging electrical cable  15 , and a battery  13  is charged by using electrical power which is supplied from the side of the power supply equipment  20  to the plug-in hybrid vehicle  10 . 
         [0052]    The plug-in hybrid vehicle  10  has a function of charging the battery  13  by using commercial AC power (for example, AC 100 V) which can be taken out from a usual domestic power supply socket. Therefore, the power supply equipment  20  may be an equipment which is disposed in a public place, or an equipment for the usual household as far as it can supply necessary commercial AC power. A predetermined electrical power supply installation  30  supplies electrical power to the power supply equipment  20 . Usually, the electrical power supply installation  30  is an equipment of an electrical power company, and corresponds to a power substation, a pole transformer, or the like. 
         [0053]    In the case of a power supply equipment in the usual household, a special apparatus for supplying electrical power to the plug-in hybrid vehicle  10 , such as a fee charging apparatus is not disposed, and hence as in the power supply equipment  20  shown in  FIG. 1 , when a power supply plug  15   a  of the charging electrical cable  15  is connected to a power supply socket  21   a , electrical power is always supplied from the power supply equipment  20  to the side of the plug-in hybrid vehicle  10 . Therefore, the owner of the plug-in hybrid vehicle  10  or the like can perform a charging operation without obtaining permission from the owner of the power supply equipment  20 , or without paying the electric power fee, and there is a possibility that the owner of the plug-in hybrid vehicle  10  or the like may perform an unauthorized charging operation (stealing of electricity). 
         [0054]    As a countermeasure against stealing of electricity and the like on the side of the power supply equipment  20 , therefore, the power-supply side charge monitoring apparatus  22  is disposed. The power-supply side charge monitoring apparatus  22  has also functions of obtaining and managing various kinds of information stored in the side of the plug-in hybrid vehicle  10 , and providing necessary information to the plug-in hybrid vehicle  10 . 
         [0055]    As shown in  FIG. 1 , the power-supply side charge monitoring apparatus  22  includes a PLC (Power Lice Communications) modem  25 , a personal computer  26 , a charging history holding portion  27 , a tachograph DB (database, the same shall apply hereinafter)  41 , and a navigation DB  42 . A power supply plug  28  disposed in a power supply cord of the PLC modem  25  is connected to one power supply socket  21   c  (or  21   a  or  21   b ). 
         [0056]    The tachograph DB  41  is a storage region for obtaining information (the vehicle speed, the number of revolutions of an engine, and the like) from digital tachographs mounted on vehicles such as the plug-in hybrid vehicle  10 , and managing the information in the personal computer  26 . The navigation DB  42  is a storage region for providing information (for example, latest map information) which is required by vehicle navigation apparatuses mounted on the vehicles such as the plug-in hybrid vehicle  10 , to the vehicle side, and obtaining information produced in the vehicle navigation apparatuses from the vehicle side to manage the information in the personal computer  26 . The information held by the navigation DB  42  is successively updated to latest information. 
         [0057]    Programs for realizing the functions of the power-supply side charge monitoring apparatus  22  are incorporated into the personal computer  26 . When the personal computer  26  executes the programs, therefore, it is possible to perform a monitor control shown in  FIG. 4 . Unique identification information (power supply-side ID) for identifying the power supply equipment  20  is previously registered in the personal computer  26 . Under the control of the personal computer  26 , history information related to the charging operation of the plug-in hybrid vehicle  10  is produced, and then stored in the charging history holding portion  27 .  FIG. 7  shows a specific example of the history information stored in the charging history holding portion  27 . 
         [0058]    In place of the personal computer  26 , a single-chip microcomputer into which programs are previously incorporated may be used, or the functions may be incorporated into the PLC modem  25 . 
         [0059]    In the side of the plug-in hybrid vehicle  10 , a charging circuit  12  for charging the battery  13 , a PLC unit (vehicle-side charge monitoring apparatus)  14 , a digital tachograph  16 , a tachograph DB  17 , a navigation apparatus  18 , and a navigation DB  19  are disposed. 
         [0060]    The PLC unit  14  is connected to a power supply line of a vehicle-side socket  11 . As described later, the PLC unit  14  has functions of dealing with an unauthorized charging operation such as stealing of electricity, and transferring information with respect to the side of the power supply equipment  20 . 
         [0061]    The digital tachograph  16  obtains various kinds of information indicating the driving situation of the plug-in hybrid vehicle  10  on which the tachograph is mounted, from sensors (not shown) mounted on the vehicle in, for example, a periodical manner, and accumulates the obtained information in the tachograph DB  17  as time series information. The tachograph DB  17  is a storage device from and into which information can be read and written. For example, the information to be stored in the tachograph DB  17  includes the vehicle speed, the number of revolutions of the engine, the driving time, the travel distance, the maximum speed, the average speed; and the time when the speed exceeds a predetermined speed. 
         [0062]    Similarly with a usual vehicle navigation apparatus, the navigation apparatus  18  has functions of: receiving radio waves from a plurality of GPS (Global Positioning System) satellites to measure the current position of the own vehicle; displaying a map containing the current position on a screen as an image; searching a route from the current position to a designated destination; and receiving a signal transmitted from a beacon transmitter disposed on a road to obtain traffic information relating traffic jam information, accident information, and the like. The navigation DB  19  is a storage device from and into which information can be read and written, and holds map information and the like to be used by the navigation apparatus  18 . 
         [0063]    As shown in  FIG. 1 , the digital tachograph  16  and the navigation apparatus  18  are connected to the PLC unit  14 . The PLC unit  14  performs the control described later, whereby information stored in the tachograph DB  17  is transferred toward the personal computer  26  on the side of the power supply equipment  20 , that stored in the navigation DB  19  is transferred toward the personal computer  26 , and the contents of the navigation DB  19  is updated to latest information by using information transmitted from the side of the personal computer  26 . 
         [0064]    In the configuration example shown in  FIG. 1 , the PLC unit  14 , the digital tachograph  16 , and the navigation apparatus  18  are configured as independent apparatuses. Alternatively, a part or the whole of these apparatuses may be integrally configured as a single apparatus. 
         [0065]    A power supply line on the input side of the charging circuit  12  is connected to the vehicle-side socket  11  via a charge switch SW. When the power supply socket  21   a  on the side of the power supply equipment  20  is electrically connected to the vehicle-side socket  11  through the charging electrical cable  15 , therefore, the commercial AC power which is supplied from the power supply equipment  20  is applied to the charging circuit  12  via the charge switch SW. The charging circuit  12  produces predetermined DC power which is required in the charging operation, from the supplied commercial AC power, and supplies the DC power to the battery  13  to charge the battery. The charge switch SW is a switch which can electrically control the connection state, such as a relay. 
         [0066]    As shown in  FIG. 2 , the PLC unit  14  which is mounted on the side of the plug-in hybrid vehicle  10  includes a PLC modem  141 , a controlling portion  142 , a vehicle ID holding portion  143 , a charging history holding portion  144 , a driver circuit  145 , and an ID database  146 . 
         [0067]    In the same manner as a usual PLC modem which is commercially available, the PLC modem  141  can transmit information with another station (another PLC modem) connected to the same power line, through the power line. In the information transmission, a carrier wave having a high frequency is used, and hence information can be transmitted without affecting the power supply. 
         [0068]    The vehicle ID holding portion  143  is a nonvolatile memory, and holds information of unique identification information (vehicle-side IDs) which is predetermined for each vehicle. The IDs held by the vehicle ID holding portion  143  cannot be rewritten. 
         [0069]    The charging history holding portion  144  is a nonvolatile memory. The contents of charging history information held by the charging history holding portion  144  are successively added or updated by history information which is produced under the control of the controlling portion  142  when the charging operation is performed. 
         [0070]    The ID database  146  is a nonvolatile memory for holding the identification information (power supply-side IDs) which is uniquely allocated to each of the various power supply facilities  20 , and used for, with respect only to a specific power supply equipment  20  in which security of information transfer has been confirmed by, for example, the user of the vehicle or a special administrator, registering and holding a power supply-side ID that is allocated to the power supply equipment. For example, there is a possibility that, when information of the vehicle side is transferred to the power supply equipment  20  which is disposed in a public place, the transferred information may leak to a third party. Therefore, the power supply-side ID of the equipment is not registered in the ID database  146 . By contrast, with respect to the power supply equipment  20  which is disposed in the home of the owner of the vehicle, and that, in a company of a specific business managing the vehicle, the possibility of leakage of transferred information may be low. Therefore, the power supply-side IDs of the facilities are registered in the ID database  146  as an equipment in which security has been confirmed. 
         [0071]    The controlling portion  142  is a microcomputer for controlling the operation of the PLC unit  14 , and performs the control shown in  FIG. 3  by using the PLC modem  141 , vehicle ID holding portion  143 , charging history holding portion  144 , driver circuit  145 , and ID database  146  which are connected to the controlling portion  142 . As a result of the control, history information related to a charging operation is produced, and the history information is stored in the charging history holding portion  144 . By the control of the controlling portion  142 , when a charging operation is performed, information is transferred between the side of the plug-in hybrid vehicle  10  and that of the power supply equipment  20  through the power supply line (charging electrical cable  15 ).  FIG. 8  shows a specific example of the history information stored in the charging history holding portion  144 . 
         [0072]      FIG. 3  schematically shows the operation of the PLC unit  14  mounted on the plug-in hybrid vehicle  10 . Referring to  FIG. 3 , the operation of the PLC unit  14  will be described. 
         [0073]    In step S 11 , the controlling portion  142  activates the PLC modem  141 . 
         [0074]    In step S 12 , the controlling portion  142  checks whether the plug-in hybrid vehicle  10 ″ and the power supply equipment  20  are connected to each other through the charging electrical cable  15  or not. Namely, the controlling portion checks whether or not the power supply plug  15   a  of the charging electrical cable  15  is connected to the power supply socket  21   a , and a power supply socket  15   b  is connected to the vehicle-side socket  11  to set a chargeable state. Actually, detection of whether the power supply socket  15   b  is inserted or not may be performed in the vicinity of the vehicle-side socket  11  by a switch, a sensor, or the like, it may be checked whether a predetermined power supply voltage appears in an electrode of the vehicle-side socket  11  or not, or it may be checked whether there is the carrier wave transmitted from the PLC modem on the side of the power supply equipment  20  or not. 
         [0075]    In step S 13 , the controlling portion  142  checks whether the PLC modem  141  is set to a state where it can communicate with the PLC modem on the side of the power supply equipment  20  or not. In the case where the power-supply side charge monitoring apparatus  22  is connected to the power supply socket  21   c  on the side of the power supply equipment  20  as shown  FIG. 1 , the PLC modem  25  in the power-supply side charge monitoring apparatus  22  operates as described later, and hence the PLC modem  141  in the plug-in hybrid vehicle  10  is set to the state where it is communicable with the side of the power supply equipment  20  (the state where a communication path is established). When the communicable state is set, the process proceeds to next step S 14 . 
         [0076]    In step S 14 , the controlling portion  142  reads the identification information held by the vehicle ID holding portion  143 , and transmits the ID as the vehicle-side ID by PLC communication. Namely, the vehicle-side ID is sent from the PLC modem  141  to the PLC modem  25  through a power line route of the power supply line—the vehicle-side socket  11 —the charging electrical cable  15 —the power supply socket  21   a.    
         [0077]    After the PLC unit  14  in the plug-in hybrid vehicle  10  sends the vehicle-side ID, as described later, the power supply-side ID is transmitted from the power-supply side charge monitoring apparatus  22  connected to the side of the power supply equipment  20 , by PLC communication. In next step S 15 , therefore, the controlling portion  142  waits for transmission of the power supply-side ID from the PLC unit  14 . When the power supply-side ID is received, the process proceeds to next step S 16 , and the received power supply-side ID is recorded into the charging history holding portion  144 . 
         [0078]    In next step S 17 , the PLC unit  14  transmits a predetermined authentication request signal to the power-supply side charge monitoring apparatus  22 . In response to the authentication request, the power-supply side charge monitoring apparatus  22  replies a result of authentication. Therefore, the PLC unit  14  checks the authentication result in step S 18 . If the authentication is OK, the process proceeds to step S 19 , and, if the authentication is NG, the process proceeds to step S 25 . 
         [0079]    In step S 19 , the controlling portion  142  controls the charge switch SW via the driver circuit  145  so as to be switched to the ON state where charging is enabled, or namely drives the charge switch SW so as to connect the power supply line, whereby the power supplied from the side of the power supply equipment  20  to the vehicle-side socket  11  through the charging electrical cable  15  is given to the charging circuit  12 . At this timing, therefore, the charging circuit  12  starts the operation of charging the battery  13 . 
         [0080]    In step S 20 , the controlling portion  142  checks whether the charging operation is ended or not. For example, the charging operation can be deemed to be ended, in the case such as that where the user operates an end button which is not shown, that where sufficient power is stored in the battery  13  and the current flowing from the charging circuit  12  to the battery  13  becomes less than a predetermined level, that where the charging electrical cable  15  is removed, or that where the carrier wave transmitted from the partner PLC modem is not detected. During the charging operation, the processes of steps S 20  to S 24  and S 26  to S 28  are repeatedly performed. 
         [0081]    During the charging operation, i.e., during a period when the plug-in hybrid vehicle  10  and the power supply equipment  20  are connected to each other and power is supplied from the power supply equipment  20  toward the plug-in hybrid vehicle  10 , the power supply-side ID is repeatedly transmitted from the power-supply side charge monitoring apparatus  22  as described later. On the power line such as the charging electrical cable  15 , as in the signal shown in  FIG. 9 , for example, information of the power supply-side ID which is transmitted as a PLC signal by the power-supply side charge monitoring apparatus  22  repeatedly appears for a predetermined time period (X1 seconds), the information of the power supply-side ID then again repeatedly appears for the predetermined time period (X2 seconds) after a separation of a predetermined time period, and, after another separation of a predetermined time period, the information of the power supply-side ID then again repeatedly appears for the predetermined time period (X3 seconds). In the example, X1, X2, and X3 are equal to one another. 
         [0082]    In step S 21 , the controlling portion  142  checks whether the PLC modem  141  continues the reception of the power supply-side ID transmitted by the power-supply side charge monitoring apparatus  22  or detects interruption of the reception corresponding to the separation. If the reception is continued, the process proceeds to step S 22 , and, if the separation is detected, the process proceeds to step S 23 . 
         [0083]    In step S 22 , the controlling portion  142  controls so that the identification information read from the vehicle ID holding portion  143  is again transmitted as the vehicle-side ID from the PLC modem  141 . During the charging operation, namely, the vehicle-side ID is repeatedly transmitted from the power-supply side charge monitoring apparatus  22  to the power supply equipment  20 , and the power supply-side ID is repeatedly transmitted from the power supply equipment  20  to the plug-in hybrid vehicle  10 . 
         [0084]    In step S 23 , the controlling portion  142  counts the number of receptions in which the power supply-side ID is received, and records the reception number into the charging history holding portion  144 . Specifically, the detection number of separations indicating that the reception of the power supply-side ID is temporarily interrupted is counted, and the separation number is recorded into the charging history holding portion  144 . In the case where the PLC modem  141  receives the signal shown in  FIG. 9 , for example, the separation between the periods of X1 and X2 is detected as a first separation, that between the periods of X2 and X3 is detected as a second separation, and, after the period of X3 is ended, a third separation is detected. Every time a separation is detected, the separation detection number which is recorded as the history in the charging history holding portion  144  is updated. 
         [0085]    In step S 24 , the controlling portion  142  records the power supply-side ID which is finally detected by the PLC modem  141 , as the history into the charging history holding portion  144 . Furthermore, the finally detected power supply-side ID is compared with that recorded in the charging history holding portion  144 , and it is checked whether the IDs are coincident with each other or not. If coincident, it is not necessary to update the record, but, if not coincident, the finally detected power supply-side ID is additionally recorded into the charging history holding portion  144  as a new history. 
         [0086]    In step S 26 , the controlling portion  142  compares the power supply-side ID which is finally detected in step S 21 , with the IDs registered in the ID database  146 , and checks whether coincidence is attained or not. Namely, it is checked whether the power supply-side ID of the power supply equipment  20  which is connected for the purpose of charging of the plug-in hybrid vehicle  10  is identical with one of the IDs in which security is previously confirmed (one of the IDs registered in the ID database  146 ). If coincidence is attained, the process proceeds to step S 27 , and, if coincidence is not attained, the process returns to step S 20 . 
         [0087]    In step S 27 , the controlling portion  142  checks whether the PLC modem  141  receives a transmission stop command from the side of the power supply equipment  20  or not. If not received, the process proceeds to step S 28 , and, if received, the process returns to step S 20 . 
         [0088]    In step S 28 , the controlling portion  142  obtains information which is accumulated by the digital tachograph  16  in the tachograph DB  17 , and sequentially transmits the information toward the power supply. equipment  20  via the PLC modem  141 . 
         [0089]    When the charging operation is to be ended, the process proceeds from step S 20  to step S 25 . In step S 25 , the controlling portion  142  controls the charge switch SW via the driver circuit  145  so as to disconnect the input of the charging circuit  12  from the power line such as the vehicle-side socket  11 , thereby ending the charging operation. 
         [0090]    When the PLC unit  14  performs the control shown in  FIG. 3 , during the charging operation, various kinds of information stored in the tachograph DB  17  are automatically transferred to the personal computer  26  on the side of the power supply equipment  20  through the charging electrical cable  15 . In the transferring of the information of the tachograph to the personal computer  26 , therefore, it is not required to use a wireless communication network; a memory card, or the like, and hence the problem of the communication cost, that of security related to information to be transferred, and the like can be solved. 
         [0091]    When the charging operation is performed, for example, history information shown in  FIG. 8  is recorded and stored in the charging history holding portion  144 . In the example shown in  FIG. 8 , information of the history indicating each charging operation includes “History number”, “Power supply-side ID”, and “Connection time”. In the above, “History number” is a number indicating the order of performing the charging operation, “Power supply-side ID” is identification information which is received from the side of the power supply equipment  20  by the PLC modem  141 , and “Connection time” means the separation detection number which is recorded in step S 23 . Since the separation appears at constant time intervals; the separation detection number corresponds to the length of the connection time or the time during which the charging operation is performed. In this way, “Connection time” is recorded for each “Power supply-side ID”. Therefore, it is possible to know the amount of the electrical power that is supplied from “Power supply-side ID” to the vehicle in which these information is recorded. 
         [0092]      FIG. 4  schematically shows the operation of the personal computer  26  in the power-supply side charge monitoring apparatus  22  connected to the power supply equipment  20 . The operation shown in  FIG. 4  will be described. 
         [0093]    In step S 31 , the personal computer  26  activates the PLC modem  25 . 
         [0094]    In step S 32 , the personal computer  26  checks whether the PLC modem  25  is communicable with the PLC modem  141  on the side of the plug-in hybrid vehicle  10  or not. When the plug-in hybrid vehicle  10  is connected to the power supply equipment  20  through the charging electrical cable  15  and the PLC unit  14  in the plug-in hybrid vehicle  10  operates, the PLC modem  25  is communicable with the PLC modem  141  in the PLC unit  14 . In this case, therefore, the process proceeds to next step S 33 . 
         [0095]    In step S 33 , the personal computer  26  checks whether the PLC modem  25  receives the vehicle-side ID transmitted from the side of the plug-in hybrid vehicle  10  or not. If the vehicle-side ID is received, the process proceeds to next step S 34 . 
         [0096]    In step S 34 , the personal computer  26  records the vehicle-side ID received in step S 33 , into the charging history holding portion  27 . 
         [0097]    In step S 35 , the personal computer  26  reads the power supply-side ID which is previously registered therein, and sends the power supply-side ID to the side of the plug-in hybrid vehicle  10  via the PLC modem  25  by PLC communication. Therefore, the PLC unit  14  on the side of the plug-in hybrid vehicle  10  can know the power supply-side ID. 
         [0098]    In step S 36 , the personal computer  26  checks whether the PLC modem  25  receives the authentication request signal from the side of the plug-in hybrid vehicle  10  or not. If the signal is received, the process proceeds to step S 37 . 
         [0099]    In step S 37 , the personal computer  26  compares vehicle-side ID received in step S 33  with IDs registered in an ID database  29 , and checks whether there is a coincident ID or not. In the ID database  29 , information of vehicle-side IDs respectively allocated to vehicles which can use the electrical power supply installation  30  are registered and held. In the case where the power supply equipment  20  is a fee charging public equipment, for example, it may be contemplated to perform a control in which, when payment of a fee is confirmed on the side of the power supply equipment  20 , the vehicle-side ID of the corresponding vehicle is registered into the ID database  29 . 
         [0100]    In step S 38 , the personal computer  26  transmits a result of the authentication in step S 37  to the side of the plug-in hybrid vehicle  10  via the PLC modem  25 . 
         [0101]    In step S 39 , the personal computer  26  checks whether the connection state between the power supply equipment  20  and the plug-in hybrid vehicle  10  is continued or not. Specifically, detection of whether the power supply plug  15   a  of the charging electrical cable  15  is connected to the power supply socket  21   a  or not is performed by a switch or the like (not shown) in the vicinity of the power supply socket  21   a , or it is checked whether there is the carrier wave sent onto the charging electrical cable  15  by the PLC modem  141  on the side of the plug-in hybrid vehicle  10  or not. 
         [0102]    In step S 40 , the personal computer  26  again transmits the power supply-side ID to the side of the plug-in hybrid vehicle  10  via the PLC modem  25  by PLC communication. Since step S 40  is repeatedly performed, the power supply-side ID is repeatedly transmitted in a short period from the PLC modem  25  during when the plug-in hybrid vehicle  10  is connected to the power supply equipment  20 . As described above, also the PLC modem  141  on the side of the plug-in hybrid vehicle  10  repeatedly transmits the vehicle-side ID. Therefore, the personal computer  26  successively fetches the received vehicle-side ID which is received by the PLC modem  25 , and checks whether the ID coincides with one of the IDs registered in the ID database  29  or not. 
         [0103]    In step S 51 , the personal computer  26  checks whether the stored information (in this example, the stored information of the tachograph) sent out from the plug-in hybrid vehicle  10  is received by the PLC modem  25  or not. If received, the process proceeds to step S 52 , and, if not received, the process proceeds to step S 41 . 
         [0104]    In step S 52 , the personal computer  26  controls the PLC modem  25  so as to perform the process of receiving stored information, and sequentially stores the received stored information into the tachograph DB  41 . 
         [0105]    In step S 53 , the personal computer  26  checks whether the reception of all stored information is completed or not. If the reception is completed, the process proceeds to step S 54 , and, if not completed, the process proceeds to step S 41 . 
         [0106]    In step S 54 , the personal computer  26  transmits a predetermined transmission stop command by using the PLC modem  25  in order to notify the side of the plug-in hybrid vehicle  10  that the reception of stored information is completed. 
         [0107]    In step S 41 , the personal computer  26  checks whether a constant time period (X seconds) which is preset has elapsed or not. If not elapsed, the process proceeds to step S 39 , and, if elapsed, the process proceeds to step S 42  after elapse of the time period. Namely, the process subsequent to step S 42  is performed at intervals of the constant time period (X seconds). 
         [0108]    In step S 42 , the personal computer  26  produces a separation time period for interrupting the transmission of the power supply-side ID. Specifically, the personal computer waits for elapse of a predetermined time period, and halts the execution of step S 40  during the tome period to stop the transmission of the power supply-side ID. 
         [0109]    Therefore, the signal sent from the PLC modem  25  toward the charging electrical cable  15  by PLC communication is set to a state such as shown in  FIG. 9 . Namely, information of the power supply-side ID which is transmitted by the PLC modem  25  as a PLC signal repeatedly appears for the predetermined time period (X1 seconds), the information of the power supply-side ID then again repeatedly appears for the predetermined time period (X2 seconds) after a separation of a predetermined time period, and, after another separation of a predetermined time period, the information of the power supply-side ID then again repeatedly appears for the predetermined time period (X3 seconds). In the example, X1, X2, and X3 have the same length (X seconds). 
         [0110]    As described above, during a period when the side of the power supply equipment  20  transmits information of the power supply-side ID, also the PLC unit  14  on the side of the plug-in hybrid vehicle  10  repeats transmission of the vehicle-side ID. Therefore, also the signal which is sent out by the PLC unit  14  is identical with that of  FIG. 9 . Namely, information of the vehicle-side ID which is transmitted by the PLC modem  141  as a PLC signal repeatedly appears for the predetermined time period (X1 seconds), the information of the vehicle-side ID then again repeatedly appears for the predetermined time period (X2 seconds) after a separation of a predetermined time period, and, after another separation of a predetermined time period, the information of the vehicle-side ID then again repeatedly appears for the predetermined time period (X3 seconds). 
         [0111]    In step S 43 , the personal computer  26  counts the number of receptions in which the vehicle-side ID is received, and records the reception number into the charging history holding portion  27 . Specifically, the number of separations in step S 42  is counted, and the separation number is recorded as a history into the charging history holding portion  27 . In the case where the finally received vehicle-side ID is different from the previously received vehicle-side IDs, the separation number is cleared, and the counting process is again started from zero. 
         [0112]    In step S 44 , the personal computer  26  records the vehicle-side ID which is finally received by the PLC modem  25 , as a history into the charging history holding portion  27 . Furthermore, the finally detected vehicle-side ID is compared with that recorded in the charging history holding portion  27 , and it is checked whether the IDs are coincident with each other or not. If coincident, it is not necessary to update the record, but, if not coincident, the finally detected vehicle-side ID is additionally recorded into the charging history holding portion  27  as a new history. 
         [0113]    As a result of the process shown in  FIG. 4  and performed by the power-supply side charge monitoring apparatus  22 , when the plug-in hybrid vehicle  10  is connected to the power supply equipment  20  and the charging operation is performed, information accumulated by the digital tachograph  16  of the plug-in hybrid vehicle  10  can be automatically transferred to the power-supply side charge monitoring apparatus  22  by using the power supply line, and the transferred information can be stored into the tachograph DB  41 . In the transferring of the information of the tachograph to the personal computer  26 , therefore, it is not required to use a wireless communication network, a memory card, or the like, and hence the problem of the communication cost, that of security related to information to be transferred, and the like can be solved. 
         [0114]    When the charging operation is performed, for example, history information shown in  FIG. 7  is recorded and stored in the charging history holding portion  27 . In the example shown in  FIG. 7 , information of the history indicating each charging operation (power supplying operation) includes “History number”, “Vehicle-side ID”, and “Connection time”. In the above, “History number” is a number indicating the order of performing the charging operation, “Vehicle-side ID” is identification information which is received from the side of the plug-in hybrid vehicle  10  by the PLC modem  25 , and “Connection time” means the separation detection number which is recorded in step S 43 . Since the separation appears at intervals of the constant time (X seconds), the separation detection number corresponds to the length of the connection time or the time during which the charging operation is performed. In this way, “Connection time” is recorded for each “Vehicle-side ID”. Therefore, it is possible to know the amount of the electrical power that is supplied to each vehicle. 
         [0115]    The timing of transmitting the vehicle-side ID as a PLC signal by the PLC unit  14  on the side of the plug-in hybrid vehicle  10 , that of transmitting the power supply-side ID as a PLC signal by the power-supply side charge monitoring apparatus  22  on the side of the power supply equipment  20 , and the like can be changed as required. However, it is preferred that the transmissions of the vehicle-side ID and the power supply-side ID are repeated at a relatively short period. 
         [0116]    As described above, the operation shown in  FIG. 3  is performed by the PLC unit  14 , and that shown in  FIG. 4  is performed by the power-supply side charge monitoring apparatus  22 , whereby the charging operation can be controlled, and information of the tachograph stored in the side of the plug-in hybrid vehicle  10  can be automatically transferred to the side the power-supply side charge monitoring apparatus  22 . 
         [0117]      FIG. 5  shows a modification of the operation shown in  FIG. 3 , and  FIG. 6  shows a modification of the operation shown in  FIG. 4 . The operation shown in  FIG. 5  is performed by the PLC unit  14 , and that shown in  FIG. 6  is performed by the power-supply side charge monitoring apparatus  22 , whereby the charging operation can be controlled, information held by the navigation DB  19  on the side of the vehicle can be transferred to the side of the power-supply side charge monitoring apparatus  22 , and conversely information held in the side of the power-supply side charge monitoring apparatus  22  can be transferred to the side of the vehicle. 
         [0118]    In  FIGS. 5 and 6 , the steps corresponding to those in  FIGS. 3 and 4  are denoted by the same step numbers. In  FIG. 5 , namely, step S 28  in  FIG. 3  is changed to steps S 61  to S 64 , and, in  FIG. 6 , steps S 71  and S 72  are added between steps S 54  and S 41 . The operation of the changed places will be described below. 
         [0119]    In step S 60  shown in  FIG. 5 , the PLC unit  14  in the plug-in hybrid vehicle  10  obtains information to be transferred, via the navigation apparatus  18  among the information stored in the navigation DB  19 , and transmits the information to the side of the power-supply side charge monitoring apparatus  22  by PLC communication. 
         [0120]    As a specific example of the information which is transmitted in step S 60  by the PLC unit  14 , traffic information (traffic jam information, accident information, and the like) which is obtained by the navigation apparatus  18  from a beacon transmitter disposed on a road, coordinate information of a position which is designated as a hazardous location by the user (driver), version information of the map data existing in the navigation DB  19 , and the like are assumed. 
         [0121]    In step S 61 , the PLC unit  14  in the plug-in hybrid vehicle  10  checks whether information transmitted from the power-supply side charge monitoring apparatus  22  is received from the power supply line or not. If received, the process proceeds to step S 62 , and, if not received, the process returns to step S 20 . 
         [0122]    In step S 62 , the PLC unit  14  controls the PLC modem  141  so as to perform the receiving process, and temporarily stores the received information into a predetermined storage device. 
         [0123]    In step S 63 , the PLC unit  14  checks whether reception of all information to be transferred is completed or not. If reception is completed, the process proceeds to step S 64 , if not completed, the process returns to step S 20 . 
         [0124]    In step S 64 , the PLC unit  14  updates information in the navigation DB  19  to latest information by using the information which is received in step S 62 . 
         [0125]    In a database such as a map which can be used by the navigation apparatus  18 , for example, latest information can be periodically obtained, and such information is usually provided in the form of an information recording medium such as a DVD, or from a server which is on the Internet, and to which the apparatus can be on-line connected. In the case where an information recording medium such as a DVD is used, however, a DVD driver for reading the medium is required, and in the case where the navigation apparatus  18  mounted on a vehicle is connected to the Internet or the like and data are downloaded, there is a possibility that the communication cost may be expensive. In the system shown in  FIG. 1 , therefore, latest information such as a map is registered in the navigation DB  42  on the side of the power-supply side charge monitoring apparatus  22 , data of the navigation DB  42  are transferred toward the plug-in hybrid vehicle  10  through the power supply line during a period when a charging operation is performed on the plug-in hybrid vehicle  10 , and, by using the data, the map and the like in the navigation DB  19  are automatically updated to data of the latest version. As information to be transferred from the side of the power-supply side charge monitoring apparatus  22  to the plug-in hybrid vehicle  10 , for example, travel plan information (information related to the destination, information related to the possible travelling route, the schedule, and the like) which is previously produced by the user may be used in addition to map data. 
         [0126]    In step S 71  shown in  FIG. 6 , by contrast, the personal computer  26  checks whether latest information to be transferred is registered in the navigation DB  42  or not. Specifically, registration dates and times of respective information are compared with each other, or the version of the map data on the side of the vehicle is compared with that of the map data in the navigation DB  42 . If latest information is registered, the process proceeds to step S 72 , and, if not registered, the process proceeds to step S 41 . 
         [0127]    In step S 72 , the personal computer  26  obtains the latest information from the navigation DB  42 , and transmits the information to the side of the plug-in hybrid vehicle  10  via the PLC modem  25 . 
         [0128]    Alternatively, both the operation shown in  FIG. 3  and that shown in  FIG. 5  may be performed in the side of the PLC unit  14 , and both the operation shown in  FIG. 4  and that shown in  FIG. 6  may be performed in the side of the power-supply side charge monitoring apparatus  22 . According to the configuration, both the transfer of information related to the tachograph function, and that of information related to the navigation function can be performed during the charging operation. 
         [0129]    As described above, the charge monitoring apparatus of the invention can be used for monitoring an operation of charging a battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and particularly also for performing transfer of information between the vehicle side and an apparatus outside the vehicle while using a power supply line connecting the vehicle side and the power supply side during a charging operation, as a transmission line. In information transfer, therefore, it is not required to use a wireless communication network, and to use a detachable information recording medium such as a memory card or a DVD, and the apparatus is useful for reducing the communication cost, and ensuring security related to information to be transferred. 
         [0130]    Although the invention has been illustrated and described for the particular preferred embodiments, it is apparent to a person skilled in the art that various changes and modifications can be made on the basis of the teachings of the invention. It is apparent that such changes and modifications are within the spirit, scope, and intention of the invention as defined by the appended claims. 
         [0131]    The present application is based on Japanese Patent Application No. 2008-314815 filed on Dec. 10, 2008, the contents of which are incorporated herein for reference.