Abstract:
An apparatus includes a wireless transmitter modulating a carrier wave by transmission data and wirelessly communicating a signal, a wireless receiver mixing the wireless transmitter signal and a carrier wave and receiving the transmission data, a power carrier wave clock generator provided on one of the wireless transmitter and receiver generating a power carrier wave clock, a non-contact power transmitter transmitting power between the wireless transmitter and receiver through electromagnetic induction from the power carrier wave clock, a carrier wave generator mounted on the one of the wireless transmitter or receiver, and generating a carrier wave based on the power carrier wave clock, and a carrier wave reproducer mounted on the other of the wireless transmitter or receiver, and reproducing a carrier wave having the same frequency as the carrier wave based on a clock having the same frequency as the power carrier wave clock.

Description:
BACKGROUND 
   1. Technical Field 
   The present invention relates to a wireless communication apparatus, and in particular, to one that is suitably applied to a method of transmitting a reference clock used for wireless data communication in a non-contact manner, together with power. 
   2. Related Art 
   As a method that transmits power to an information terminal apparatus, such as a cellular phone, for the sake of charging, there is a method that transmits power using electromagnetic induction in a non-contact manner, in addition to a method that transmits power through a metal contact, such as a connector. The method that transmits power in a non-contact manner can have no poor contact by abrasion or stain and can maintain a waterproof property of a case, compared with the method that transmits power through the metal contact. 
   In JP-A-9-103037, there is disclosed a method that transfers power control information through an electromagnetic induction coil for power transmission such that a feedback control of supplied power can be performed without impairing the advantages of non-contact power feeding. Further, in JP-A-2005-73350, there is disclosed a method that provides a coil for data communication separately from a coil for power transmission in order to implement an electric tool that can perform optimum charging according to the state of a charger. 
   Meanwhile, in JP-A-6-133476, there is disclosed a method that performs wireless data communication using an antenna separately from a non-contact power transmission device so as to enable data communication, without being restricted by a power transmission side. 
   However, in the method that transmits power in the non-contact manner for the sake of charging or the like, in order to transfer mass image data stored in the information terminal apparatus, such as a digital camera or a cellular phone with a camera, to a personal computer, a connector for wired communication, such as a USB, is required, and thus there is a problem in that the above method cannot cope with transmission of mass image data. 
   In the methods disclosed in JP-A-9-103037 and JP-A-2005-73350, data communication is performed through a power transmission device, such as an electromagnetic induction coil, and thus there is a problem in that high-speed data communication cannot be performed. 
   In the method disclosed in JP-A-6-133476, a wireless machine is merely provided alone separately from the non-contact power transmission device, and thus there is a problem in that costs, power consumption, and the size are increased. 
   Meanwhile, in order to perform transmission of mass data, it is necessary to provide a local oscillator for generating a reference clock on transmitting and receiving sides. Further, it is necessary to provide an automatic frequency adjusting circuit or an A/D converter for adjusting a shift in frequency of the reference clock on the transmitting and receiving sides. Accordingly, there is a problem in that the size of the circuit is increased. 
   SUMMARY 
   An advantage of some aspects of the invention is to provide a wireless communication apparatus that can transmit power without causing poor contact, suppress an increase in size of a circuit, and implement high-speed data communication in a wireless manner. 
   According to a first aspect of the invention, a wireless communication apparatus includes a wireless transmitting unit that modulates a carrier wave by transmission data and performs wireless communication of a signals a wireless receiving unit that mixes the signal transmitted from the wireless transmitting unit in a wireless manner and a carrier wave having the same frequency component as the carrier wave and performs reception of the transmission data, a power carrier wave clock generating unit that is provided on one of the wireless transmitting unit and the wireless receiving unit so as to generate a power carrier wave clock, a non-contact power transmitting unit that transmits power between the wireless transmitting unit and the wireless receiving unit through electromagnetic induction generated by the power carrier wave clock, a carrier wave generating unit that is mounted on either the wireless transmitting unit or the wireless receiving unit where the power carrier wave clock generating unit is provided, and generates a carrier wave on the basis of the power carrier wave clock, and a carrier wave reproducing unit that is mounted on either the wireless transmitting unit or the wireless receiving unit where the power carrier wave clock generating unit is not provided, and reproduces a carrier wave having the same frequency component as the carrier wave generated by the carrier wave generating unit on the basis of a clock having the same frequency component as the power carrier wave clock induced on a power reception side of the non-contact power transmitting unit. 
   With this configuration, power can be transmitted in a non-contact manner between the wireless transmitting unit and the wireless receiving unit, and the carrier waves can be generated in the wireless transmitting unit and the wireless receiving unit on the basis of the same power carrier wave clock. For this reason, even though wireless data communication is performed between the wireless transmitting unit and the wireless receiving unit, a local oscillator for generating a reference clock, or an automatic frequency adjusting circuit or an A/D converter for adjusting a shift in frequency of the reference clock on transmitting and receiving sides is not required. Therefore, an increase in size of a circuit can be suppressed, high-speed data communication can be implemented in a wireless manner, and power can be transmitted without causing poor contact. 
   An overhead for adjusting the shift in frequency of the carrier wave between the transmitting and receiving sides can be eliminated, and throughput upon wireless communication can be improved. In addition, complete synchronous detection can be implemented, and optimum communication quality can be maintained. 
   Here, as the non-contact power transmitting unit, for example, coils that are electromagnetically provided on the wireless transmitting unit and the wireless receiving unit can be used. 
   In the wireless communication apparatus according to the first aspect of the invention, the carrier wave reproducing unit may include a voltage dropping circuit that lowers a voltage of the clock having the same frequency component as the power carrier wave clock induced on the power reception side of the non-contact power transmitting unit, and a frequency multiplying unit that multiplies a frequency of the clock whose voltage is dropped by the voltage dropping circuit. 
   In the wireless communication apparatus according to the first aspect of the invention, the non-contact power transmitting unit may have a first coil on a power transmission side and a second coil on the power reception side. In this case, the carrier wave reproducing unit may include a third coil that is electromagnetically coupled to the second coil and on which a third clock having the same frequency component as the power carrier wave clock by the clock having the same frequency component as the power carrier wave clock induced on the second coil is induced, and a frequency multiplying unit that receives power from the third coil and multiplies a frequency of the clock induced on the third coil. 
   According to a second aspect of the invention, a wireless communication apparatus includes a primary module and a secondary module that are provided separably from each other, a wireless transmitting unit that is mounted on the primary module, and modulates a carrier wave by transmission data and performs wireless communication of a signal, a wireless receiving unit that is mounted on the secondary module, and mixes the signal transmitted from the wireless transmitting unit in a wireless manner and a carrier wave having the same frequency component as the carrier wave and receives the transmission data, a power carrier wave clock generating unit that is mounted on either the primary module or the secondary module and generates a power carrier wave clock, a non-contact power transmitting unit that transmits power between the primary module and the secondary module through electromagnetic induction generated by the power carrier wave clock, a carrier wave generating unit that is provided on either the primary module or the secondary module where the power carrier wave clock generating unit is mounted, and generates a carrier wave on the basis of the power carrier wave clock, and a carrier wave reproducing unit that is provided on either the primary module or the secondary module where the power carrier wave clock generating unit is not mounted, and reproduces a carrier wave having the same frequency component as the carrier wave generated by the carrier wave generating unit on the basis of a clock having the same frequency component as the power carrier wave clock induced on a power reception side of the non-contact power transmitting unit. 
   With this configuration, an increase in size of a circuit can be suppressed, and data communication can be performed between the primary module and the secondary module in a wireless manner. Further, an increase in costs, power consumption, and size can be suppressed, and high-speed communication of mass data can be performed. In addition, power can be transmitted without causing poor contact. 
   According to a third aspect of the invention, a wireless communication apparatus includes a first casing, a second casing, a connection unit that connects the first casing and the second casing so as to change a positional relationship between the first casing and the second casing, an external wireless communication unit that is mounted on the first casing and performs external wireless communication, a display unit that is mounted on the second casing, an internal wireless communication unit that is mounted on the first casing, and modulates a carrier wave by transmission data and performs internal wireless transmission of a signal, an internal wireless receiving unit that is mounted on the second casing, and mixes the signal transmitted from the internal wireless transmitting unit in an internal wireless manner and a carrier wave having the same frequency component as the carrier wave and receives the transmission data in an internal wireless manner, a power carrier wave clock generating unit that is mounted on either the first casing or the second casing and generates a power carrier wave clock, a non-contact power transmitting unit that transmits power between the first casing unit and the second casing through electromagnetic induction generated by the power carrier wave clock, a carrier wave generating unit that is provided on either the first casing or the second casing where the power carrier wave clock generating unit is mounted, and generates a carrier wave on the basis of the power carrier wave clock, and a carrier wave reproducing unit that is provided on either the first casing or the second casing where the power carrier wave clock generating unit is not mounted, and reproduces a carrier wave having the same frequency component as the carrier wave generated by the carrier wave generating unit on the basis of a clock having the same frequency component as the power carrier wave clock induced on a power reception side of the non-contact power transmitting unit. 
   With this configuration, even though the size of display data to be transmitted from the first casing to the second casing is increased with large screen and large definition of the display unit mounted on the second casing, the display data can be transmitted to the display unit at high speed without complicating the configuration of the connection unit, and power can be transmitted without causing poor contact. For this reason, a small and thin wireless communication terminal and high reliability can be implemented. In addition, a wireless communication terminal having a large screen and multi-functionality can be implemented without impairing portability of the wireless communication terminal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
       FIG. 1  is a block diagram showing the schematic configuration of a wireless communication apparatus according to a first embodiment of the invention. 
       FIG. 2  is block diagram showing the schematic configuration of a wireless communication apparatus according to a second embodiment of the invention. 
       FIGS. 3A and 3B  are diagrams showing a clamshell cellular phone to which a wireless communication apparatus according to a third embodiment of the invention is applied. 
       FIG. 4  is an external view showing the system configuration to which a wireless communication apparatus according to a fourth embodiment of the invention is applied. 
   

   DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   Hereinafter, a wireless communication apparatus and a method of manufacturing the same according to embodiments of the invention will be described with reference to the drawings. 
     FIG. 1  is a block diagram showing the schematic configuration of a wireless communication apparatus according to a first embodiment of the invention. 
   Referring to  FIG. 1 , in a primary module M 1 , a baseband unit  1  that performs a baseband signal processing, a control unit  2  that performs the control of the baseband unit  1  and the like, a ROM  3  that stores various programs for operating the primary module M 1 , a RAM  4  that provides a work area when the control unit  2  executes a processing or stores the processing result, a power carrier wave clock generating unit  5  that generates a power carrier wave clock, a voltage boosting circuit  6  that boosts the power carrier wave clock, a primary coil  7   a  (power transmission side) that generates a voltage on a secondary coil  7   b  on the basis of electromagnetic induction, a delay adjusting unit  8  that adjusts a phase of the power carrier wave clock, a PLL circuit  9  that generates a carrier wave by multiplying a frequency of the power carrier wave clock, a low pass filter  10  that attenuates an unnecessary high component included in a transmission signal TXD 1  output from the baseband unit  1 , a mixer  11  that up-converts the transmission signal TXD 1  by mixing the transmission signal TXD 1  to the carrier wave, an internal wireless communication antenna  14  that performs transmission/reception of an electric wave for internal wireless communication, a band pass filter  13  that attenuates an unnecessary frequency component from the signal received by the internal wireless communication antenna  14 , a low noise amplifier  15  that amplifies the signal received by the internal wireless communication antenna  14 , a mixer  16  that down-converts the received signal by mixing the received signal output from the low noise amplifier  15  to the carrier wave, a low pass filter  17  that attenuates an unnecessary high component included in the down-converted received signal, a buffer is that amplifies the received signal output from the low pass filter  17  and outputs a received signal RXD 1  and a switch  12  that switches transmission/reception in the primary module M 1  are provided. 
   In a secondary module M 2 , a baseband unit  21  that performs a baseband signal processing, a control unit  22  that performs the control of the baseband unit  21  and the like, a ROM  23  that stores various programs for operating the secondary module M 2 , a RAM  24  that provides a work area when the control unit  22  executes a processing or stores the processing result, a secondary coil  7   b  (power reception side) that generates a voltage on the basis of electromagnetic induction with the primary coil  7   a , diodes  25   a  to  25   d  that are brought into bridge connection so as to rectify the voltage generated on the secondary coil  7   b , a capacitor  26  that generates a direct current voltage by accumulating an electric charge, a voltage regulator circuit  27  that performs voltage adjustment, a voltage dropping circuit  28  that drops the voltage generated on the secondary coil  7   b , a PLL circuit  29  that generates a carrier wave by multiplying a frequency of the power carrier wave clock dropped by the voltage dropping circuit  28 , a low pass filter  30  that attenuates an unnecessary high component included in a transmission signal TXD 2  output from the baseband unit  21 , a mixer  31  that up-converts the transmission signal TXD 2  by mixing the transmission signal TXD 2  to the carrier wave, an internal wireless communication antenna  32  that performs transmission/reception of an electric wave for internal wireless communication, a band pass filter  33  that attenuates an unnecessary frequency component from the signal received by the internal wireless communication antenna  32 , a low noise amplifier  35  that amplifies the signal received by the internal wireless communication antenna  32 , a mixer  36  that down-converts the received signal by mixing the received signal output from the low noise amplifier  35  to the carrier wave, a low pass filter  37  that attenuates an unnecessary high component included in the down-converted received signal, a butter  38  that amplifies the received signal output from the low pass filter  37  and outputs a received signal RXD 2  to the baseband unit  21 , and a switch  34  that switches transmission/reception in the secondary module M 2  are provided. 
   When the transmission data TXD 1  is transmitted from the primary module M 1  to the secondary module M 2 , the switch  12  is switched to the mixer  11 , and the switch  34  is switched to the low noise amplifier  35 . The power carrier wave clock generating unit  5  generates a power carrier wave clock and sends the generated power carrier wave clock to a delay adjusting unit  8 . Then, after a phase of the power carrier wave clock is adjusted by the delay adjusting unit  8 , a frequency of the power carrier wave clock is multiplied by the PLL circuit  9 , and the power carrier wave clock having the multiplied frequency is output to the mixers  11  and  16 . Further, the baseband unit  1  generates the transmission data TXD 1 , and output the generated transmission data TXD 1  to the mixer  11  through the low pass filter  10 . Then, the mixer  11  mixes the transmission data TXD 1  output from the baseband unit  1  and the carrier wave output from the PLL circuit  9 , and superimposes the transmission data TXD 1  on the carrier wave. 
   If the transmission data TXD 1  is superimposed on the carrier wave, the transmission data is sent to the internal wireless communication antenna  14  through the switch  12  and the band pass filter  13 , and then is sent to a space as an electric wave through the internal wireless communication antenna  14 . Next, if the transmission data is transmitted through the internal wireless communication antenna  14 , the transmission data is received through the internal wireless communication antenna  14 . 
   Further, the power carrier wave clock generated by the power carrier wave clock generating unit  5  is sent to the voltage boosting circuit  6 , then is boosted by the voltage boosting circuit  6 , and subsequently is sent to the primary coil  7   a . Then, the power carrier wave clock is sent to the primary coil  7   a , a voltage (clock) having a frequency component of the power carrier wave clock is induced by electromagnetic induction with the secondary coil  7   b , then is smoothed by the diodes  25   a  to  25   d  and the capacitor  26 , and subsequently is sent to an apparatus power supply through the voltage regulator circuit  27 . 
   The voltage induced on the secondary coil  7   b  is sent to the voltage dropping circuit  28 , then is dropped by the voltage dropping circuit  28 , and subsequently is sent to the PLL circuit  29 . Next, the frequency component of the power carrier wave clock induced on the secondary coil  7   b  is multiplied by the PLL circuit  29  and then is output to the mixers  31  and  36 . That is, a carrier wave having the same frequency component as the carrier wave generated by the PLL circuit  9  of the primary module M 1  is reproduced by the PLL circuit  29 . 
   Next, the received signal received through the internal wireless communication antenna  32  is sent to the low noise amplifier  35  through the switch  34  after an unnecessary frequency component is attenuated by the band pass filter  33  therefrom. Next, if the received signal is sent to the low noise amplifier  35 , it is amplified by the low noise amplifier  35  and then is sent to the mixer  36 . 
   Next, the mixer  36  mixes the received signal sent from the low noise amplifier  35  and the carrier wave sent from the PLL circuit  29 , and performs down conversion of the received signal. Next, the received signal RXD 2  down-converted by the mixer  36  is sent to the baseband unit  21  through the buffer  38  after an unnecessary frequency component is attenuated by the low pass filter  37 . 
   Meanwhile, when the transmission data TXD 2  is transmitted from the secondary module M 2  to the primary module M 1 , the switch  12  is switched to the low noise amplifier  15 , and the switch  34  is switched to the mixer  31 . The power carrier wave clock generating unit  5  generates a power carrier wave clock and sends the generated power carrier wave clock to the delay adjusting unit  8 . Next, after the phase of the power carrier wave clock is adjusted by the delay adjusting unit  8 , the frequency of the power carrier wave clock is multiplied by the PLL circuit  9 , and then the power carrier wave clock having the multiplied frequency is output to the mixers  11  and  16   
   The power carrier wave clock generated by the power carrier wave clock generating unit  5  is sent to the voltage boosting circuit  6 , then is boosted by the voltage boosting circuit  6 , and subsequently is sent to the primary coil  7   a . Next, if the power carrier wave clock is sent to the primary coil  7   a , a voltage having the frequency component of the power carrier wave clock is induced by electromagnetic induction with the secondary coil  7   b , then is smoothed by the diodes  25   a  to  25   d  and the capacitor  26 , and subsequently is sent to the apparatus as power supply through the voltage regulator circuit  27 . 
   The voltage induced on the secondary coil  7   b  is sent to the voltage dropping circuit  28 , then is dropped by the voltage dropping circuit  28 , and subsequently is sent to the PLL circuit  29 . Next, the frequency component of the power carrier wave clock induced on the secondary coil  7   b  is multiplied by the PLL circuit  29 , and the power carrier wave clock having the multiplied frequency component is sent to the mixers  31  and  36 . 
   The baseband unit  21  generates the transmission data TXD 2 , and outputs the generated transmission data TXD 2  to the mixer  31  through the low pass filter  30 . Next, the mixer  31  mixes the transmission data TXD 2  output from the baseband unit  21  and the carrier wave output from the PLL circuit  29  and superimposes the transmission data TXD 2  on the carrier wave. 
   If the transmission data TXD 2  is superimposed on the carrier wave, the transmission data is sent to the internal wireless communication antenna  32  through the switch  34  and the base band filter  33 , and then is output to a space as an electric wave through the internal wireless communication antenna  32 . Next, if the transmission data is transmitted through the internal wireless communication antenna  32 , the transmission data is transmitted through the internal wireless communication antenna  32  and then is received through the internal wireless communication antenna  14 . 
   The received signal received through the internal wireless communication antenna  14  is sent to the low noise amplifier  13  through the switch  12  after an unnecessary frequency component is attenuated by the band pass filter  13 . Next, the received signal is sent to the low noise amplifier  15  then is amplified by the low noise amplifier  15 , and subsequently is sent to the mixer  16 . 
   The mixer  16  mixes the received signal sent from the low noise amplifier  15  and the carrier wave sent from the PLL circuit  9  and performs down conversion of the received signal. Next, the received signal RXD 1  down-converted by the mixer  16  is sent to the baseband unit  1  through the buffer  18  after an unnecessary high component is attenuated by the low pass filter  17 . 
   Accordingly, power can be transmitted between the primary module M 1  and the secondary module M 2  that are separately provided, and the carrier wave can be generated on the basis of the same power carrier wave clock in the primary module M 1  and the secondary module M 2 . For this reason, even though wireless data communication is performed between the primary module M 1  and the secondary module M 2 , a local oscillator for generating a reference clock, or an automatic frequency adjusting circuit or an A/D converter for adjusting a shift in frequency of the reference clock between the primary module M 1  and the secondary module M 2  is not required. Therefore, an increase in size of a circuit can be suppressed, and high-speed data communication can be implemented in a wireless manner. In addition, power can be transmitted without causing poor contact. 
   An overhead for adjusting a shift in frequency of the carrier wave between the primary module M 1  and the secondary module M 2  can be eliminated, and throughput upon wireless communication can be improved. Further, complete synchronous detection can be implemented, and optimum communication quality can be maintained. In addition, an on-time can be made short upon intermittent transmission/reception, and thus power consumption can be reduced. 
   In the above-described first embodiment, the power carrier wave clock generating unit is provided on the wireless transmission side. However, the power carrier wave clock generating unit may be provided on the wireless reception side. The same can be applied to the following second to fourth embodiments. 
     FIG. 2  is a block diagram showing the schematic configuration of a wireless communication apparatus according to a second embodiment of the invention. 
   Referring to  FIG. 2 , in the secondary module M 2 , instead of the voltage dropping circuit  28  of  FIG. 1 , a tertiary coil  7   c  that is electromagnetically coupled to the secondary coil  7   b  is provided. 
   A voltage (clock) induced on the tertiary coil  7   c  is supplied to the PLL circuit  29 , and the PLL circuit  29  can multiply the frequency component of the power carrier wave clock induced on the tertiary coil  7   c  and output the power carrier wave to the mixers  31  and  36 . 
   Accordingly, it is unnecessary to provide the voltage dropping circuit  28  of  FIG. 1 , and thus the circuit configuration is simplified. In additions the frequency component of the power carrier wave clock can be efficiently extracted. 
   The above-described wireless communication apparatus can be applied, for example, to a cellular phone, a video camera, a PDA (Personal Digital Assistant), a notebook type personal computer, and the like. Further, in the above embodiments, a method that performs communication between the primary module M 1  and the secondary module M 2  has been described. However, the invention may be applied to wireless communication between a first casing and a second casing that are connected to each other through a hinge or wireless communication in an apparatus that is used as a single body. 
     FIGS. 3A and 3B  are diagrams showing a clamshell cellular phone that is a wireless communication apparatus as a third embodiment of the invention. The clamshell cellular phone of  FIGS. 3A and 3B  substantially has the same configuration as the wireless communication apparatus of the first or second embodiment described with reference to  FIG. 1  or  2  in terms of a circuit system, and has features in terms of casings and mounting. 
     FIG. 3A  is a perspective view showing a state where the clamshell cellular phone is opened  FIG. 3B  is a perspective view showing a state where the clamshell cellular phone is closed. 
   Referring to  FIGS. 3A and 3B , operating buttons  304  are disposed at a surface of a first casing  301 , and a microphone  305  is provided at a lower end of the first casing  301 . An external wireless communication antenna  306  is attached at an upper end of the first casing  301 . Further, a display unit  308  is provided at a surface (a surface viewed in an opened state) of a second casing  302 , and a speaker is provided at an upper end of the second casing  302 . 
   A display body  311  and an imaging device  312  are provided at a rear surface (an outer surface in a closed state) of the second casing  302 . Moreover, as the display unit  308  and the display body  311 , a liquid crystal display panel, an organic EL panel, or a plasma display panel is applied. Further, as the imaging device  312 , a CCD, a CMOS sensor or the like is applied. 
   In the first casing  301  and the second casing  302 , internal wireless communication antennas  307  and  310  for internal wireless communication between the first casing  301  and the second casing  302  are provided, respectively. As shown in the drawings, the first casing  301  and the second casing  302  are connected to each other through a hinge  303  as a coupling mechanism (a connection unit). The second casing  302  rotates with the hinge  303  as a fulcrum, such that the second casing  302  is folded onto the first casing  301 . 
   In the above-described manner, since the second casing  302  is closed onto the first casing  301 , the operating buttons  304  can be protected by the second casing  302 , and the operating buttons  304  can be prevented from erroneously operating when a user takes the cellular phone. Further, when the second casing  302  is opened from the first casing  301 , the user can operate the operating buttons  304  while viewing the display unit  308 , talk over the phone using the speaker  309  and the microphone  305 , or perform imaging while operating the operating buttons  304 . 
   Since the clamshell structure is used, the display unit  308  can be disposed at the substantially entire surface of the second casing  302 , and the size of the display unit  308  can be expanded without damaging portability as a cellular phone. As a result, visibility can be improved. 
   According to the above configuration, in the cellular phone, the internal wireless communication antenna  307  is provided in the first casing  301 , and the internal wireless communication antenna  310  is provided in the second casing  302 . Therefore, data transmission between the first casing  301  and the second casing  302  is performed by internal wireless communication using the internal wireless communication antennas  307  and  310 . 
   In the cellular phone of  FIGS. 3A and 3B , the primary module M 1  of  FIG. 1  or  2  is provided in the first casing  301 , and the secondary module M 2  of  FIG. 1  or  2  is provided in the second casing  302 . 
   The internal wireless communication antenna  307  corresponds to the internal wireless communication antenna  14  of  FIG. 1  or  2 , and the internal wireless communication antenna  310  corresponds to the internal wireless communication antenna  32  of  FIG. 1  or  2 . 
   According to the above configuration, for example, image data or sound data that is imported to the first casing  301  through the external wireless communication antenna  306  is sent to the second casing  302  by internal wireless communication using the internal wireless communication antennas  307  and  310 , and then an image may be displayed on the display unit or sound may be output from the speaker  309 . 
   A captured image by the imaging device  312  is sent from the second casing  302  to the first casing  301  by internal wireless communication using the internal wireless communication antennas  307  and  310 . Then, the captured image may be sent to the outside through the external wireless communication antenna  306 . 
   As described above, it is unnecessary to perform data transmission between the first casing  301  and the second casing  302  in a wired manner. Further, it is unnecessary to connect a flexible wiring board having a plurality of pins to the hinge  303 . 
   Power can be transmitted between the first casing  301 , in which the primary module M 1  is provided, and the second casing  302 , in which the secondary module M 2  is provided, in a non-contact manner. Further, the carrier wave can be generated on the basis of the same power carrier wave clock in the primary module M 1  and the secondary module M 2 . For this reason, power can be transmitted without connecting an electrical wire for transferring power between the first casing  301  and the second casing  302  to the hinge  303 . Further, even though wireless data communication is performed between the primary module M 1  and the secondary module M 2 , a local oscillator for generating a reference clock, or an automatic frequency adjusting circuit or an A/D converter for adjusting a shift in frequency of the reference clock between the primary module M 1  and the secondary module M 2  is not required. Therefore, an increase in size of a circuit can be suppressed, and high-speed data communication can be implemented in a wireless manner. 
   In this embodiment, the clamshell cellular phone has been described. However, the above-described wireless communication technology can be applied to various electronic apparatuses, such as a rotary cellular phone and a notebook type personal computer. 
     FIG. 4  is an external view showing the system configuration to which a wireless communication apparatus according to a fourth embodiment of the invention is applied. 
   In  FIG. 4 , it is assumed that the secondary module M 2  of  FIG. 1  is mounted on a digital camera  51 , and the primary module M 1  of  FIG. 1  is mounted on a charging stand  52 . Then, alternating current power is supplied to the charging stand  52  through an AC adaptor  54 , and the charging stand  52  is connected to a personal computer  53  through a wired cable  55  based on a USB standard or the like. 
   The charging stand  52  can charge the digital camera  51  through non-contact power transmission and perform wireless data communication with the digital camera  51 . Then, the charging stand  52  can transfer digital data to the personal computer  53 . 
   The connection of the charging stand  52  and the personal computer  53  may be made using wireless connections in addition to the wired cable  55 . Further, in the embodiment of  FIG. 4 , the description has been given by way of the digital camera  51 , but may be applied to a cellular phone or a video camera. 
   The entire disclosure of Japanese Patent Application Nos. 2005-304314, filed Oct. 19, 2005 and 2006-226007, filed Aug. 23, 2006 are expressly incorporated by reference herein.