Abstract:
Provided is a portable terminal capable of ensuring satisfactory antenna characteristics regardless of a change in state, and of accommodating a plurality of frequency bands. A first circuit unit comprises: a first signal source; a first power feeding unit connected to a first antenna unit; a second power feeding unit connected to a first connection unit; a first switching unit which connects the first power feeding unit or the second power feeding unit to the first signal source by switching; and a first control unit which controls the first switching unit so as to connect the second power feeding unit to the first signal source when the portable terminal is transitioned to a second state. A first disconnection unit is disposed between the first connection unit and the first circuit unit and disconnects a first signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the National Stage of International Application No. PCT/JP2010/055444, filed Mar. 26, 2010, which claims the benefit of Japanese Application No. 2009-077771, filed Mar. 26, 2009, the entire contents of all of which are incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The present invention relates to a mobile terminal device including a first body and a second body. 
     BACKGROUND OF THE INVENTION 
     Among cellular telephone devices as a type of a mobile terminal device that is configured with a first body with an operation unit formed on a top face, and a second body with a display unit formed on a top face, there is a cellular telephone device including a sliding mechanism. By utilizing the sliding mechanism, the cellular telephone device can transition to a state in which the second body covers the operation unit formed on the top face of the first body, by mutually superimposing the first body and the second body such that the display unit is exposed to the outside (hereinafter referred to as a slid-down state), and a state in which the operation unit formed on the top face of the first body is exposed, by sliding the second body in a longitudinal direction relative to the first body (hereinafter referred to as a slid-up state). 
     By sliding the first body and the second body, a cellular telephone device including such a sliding mechanism transitions to the slid-up state in which the display unit and the operation unit are exposed to the outside, and as a result, it is possible to achieve convenience that key operations can be performed while visually confirming the display screen. Furthermore, the cellular telephone device in the slid-down state has an external appearance that only the display of the first body is exposed to the outside, and as a result, it is possible to achieve space-saving. In addition, if the display is configured with a touch sensor, and/or if a simplified operation unit is formed on the top face of the second body, the cellular telephone device in the slid-down state can also secure operability while achieving space-saving. 
     For a cellular telephone device including such a sliding mechanism, a method has been proposed, in which a circuit board and a conductor in the bodies are used as antennas (see Patent Document 1).  FIGS. 10A ,  10 B,  11 A and  11 B are cross-sectional views schematically showing an internal structure of a portable wireless device  200 . Moreover, a first body  201  includes an operation unit  202 , a circuit board  203 , and an antenna  204 . A second body  301  includes an operation unit  302 , a display  303 , and a circuit board  304 . 
     According to a first embodiment of Patent Document  1 , in the slid-down state ( FIG. 10A ), the portable wireless device  200  as an example of a mobile terminal device is configured such that a connection part  204   a  electrically connected to the antenna  204  is not superimposed, i.e. not coupled at high frequency, with the circuit board  304  of the second body  301  in a thickness direction. As a result, satisfactory antenna characteristics can be achieved in the portable wireless device  200  in the slid-down state. 
     In addition, the portable wireless device  200  in the slid-up state ( FIG. 10B ) is configured to supply power to the circuit board  304  of the second body  301  via the connection part  204   a  that is electrically connected to the antenna  204 , so that the circuit board  304  is utilized as an antenna element. As a result, satisfactory antenna characteristics can be achieved in the portable wireless device  200  in the slid-up state. A virtual line A in  FIG. 10B  schematically shows an aspect in which a high-frequency current is supplied from the first body  201  side to the second body  301  side by connecting the connection part  204   a  and the circuit board  304 . 
     Furthermore, according to a second embodiment of Patent Document 1, although an outline thereof is substantially similar to that of the first embodiment, the portable wireless device  200  in the slid-up state ( FIG. 11A ) is configured such that the circuit board  304  is utilized as an antenna element by capacitively coupling the antenna  204  and the circuit board  304  of the second body  301 . More specifically, in the portable wireless device  200  in the slid-up state, the antenna  204  and the circuit board  304  of the second body  301  face each other at a predetermined interval to be capacitively coupled with each other. As a result, satisfactory antenna characteristics can be achieved in the portable wireless device  200  in the slid-up state. A virtual line B in  FIG. 11A  schematically shows an aspect in which a high-frequency current is supplied from the first body  201  side to the second body  301  side by capacitively coupling the antenna  204  and the circuit board  304 . 
     Moreover, similarly to  FIG. 10A , the portable wireless device  200  in the slid-down state ( FIG. 11B ) is configured such that the antenna  204  and the circuit board  304  of the second body  301  do not face each other, and are not capacitively coupled with each other. As a result, satisfactory antenna characteristics can be achieved in the portable wireless device  200  in the slid-down state. 
     Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2006-67361 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, in a conventional mobile terminal device such as that disclosed in Patent Document 1, the first body and the second body are mutually superimposed, so that high-frequency currents flowing in the first body and the second body may cancel each other, and as a result, satisfactory antenna characteristics may be difficult to be secured in some cases. 
     An object of the present invention is to secure satisfactory antenna characteristics. 
     Means for Solving the Problems 
     In order to solve the aforementioned problems, the mobile terminal device according to the present invention includes: a first body; a second body; a first conductive portion disposed in the first body and including a first contact point; a second conductive portion disposed in the second body and including a second contact point; and a first circuit unit disposed in any one of the first body and the second body, the first circuit unit including: a first ground unit connected to the first conductive portion via the first contact point; a first power supply unit connected to the second conductive portion via the second contact point; and a first signal processing unit connected to the first power supply unit, configured to process a first high frequency signal resonated by the second conductive portion, in which the first conductive portion includes a first area overlapping with the second conductive portion, the second conductive portion includes a second area overlapping with the first conductive portion, and a first cutoff part is connected to at least one of the first conductive portion and the second conductive portion, and cuts off transmission of the first high frequency signal to an area toward a fist end side from the first contact point of the first area, or to an area toward a second end side from the second contact point of the second area. 
     Moreover, in the mobile terminal device, a transmission path length of the first high frequency signal in the area toward the second end side from the first contact point of the first conductive portion is preferably substantially identical to a transmission path length of the first high frequency signal in the area toward the first end side from the second contact point of the second conductive portion. 
     In addition, it is preferable for the mobile terminal device to further include a second circuit unit disposed in any one of the first body and the second body, the second circuit unit including: a second ground unit connected to any one of the first conductive portion and the second conductive portion via any one of the first contact point and the second contact point; a second power supply unit connected to another one of the first conductive portion and the second conductive portion via another one of the first contact point and the second contact point; and a second signal processing unit connected to the second power supply unit, configured to process a second high frequency signal resonated by another one of the first conductive portion and the second conductive portion, in which a second cutoff part is connected to at least one of the first conductive portion and the second conductive portion, and cuts off transmission of the second high frequency signal to an area toward the second end side from the first contact point of the first area, or to an area toward the first end side from the second contact point of the second area. 
     Furthermore, in the mobile terminal device, a transmission path length of the second high frequency signal in the area toward the first end side from the first contact point of the first conductive portion is preferably substantially identical to a transmission path length of the second high frequency signal in the area toward the second end side from the second contact point of the second conductive portion. 
     Moreover, in the mobile terminal device, frequency of the first high frequency signal is preferably different from frequency of the second high frequency signal. 
     In addition, in the mobile terminal device, the first contact point and the second contact point are preferably capacitively coupled with each other. 
     Furthermore, in the mobile terminal device, the first cutoff part preferably includes a parallel resonant circuit including a capacitor having predetermined capacity and a coil. 
     Moreover, in the mobile terminal device, the second cutoff part preferably includes a parallel resonant circuit including a capacitor having predetermined capacity and a coil. 
     Effects of the Invention 
     According to the present invention, while employing a method in which the circuit board and the conductor in the bodies are used as antennas, satisfactory antenna characteristics can be secured, and compatibility with a plurality of frequency bands can be established, in the slid-up state and the slid-down state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an appearance of a cellular telephone device in a slid-down state (first state) according to the present invention; 
         FIG. 2  is a perspective view showing an appearance of the cellular telephone device in a slid-up state (second state) according to the present invention; 
         FIG. 3  is a view schematically showing a cross section of the cellular telephone device according to the present invention; 
         FIG. 4A  is a view schematically showing a cross section of the cellular telephone device in the second state according to the present invention; 
         FIG. 4B  is a view schematically showing a cross section of the cellular telephone device in the second state according to the present invention; 
         FIG. 5A  is a view schematically showing an internal configuration of a display unit side body shown in  FIGS. 4A and 4B ; 
         FIG. 5B  is a view schematically showing an internal configuration of the display unit side body shown in  FIGS. 4A and 4B ; 
         FIG. 6  is a view schematically showing a cross section of the cellular telephone device according to the present invention; 
         FIG. 7A  is a view schematically showing a cross section of the cellular telephone device in the second state according to the present invention; 
         FIG. 7B  is a view schematically showing a cross section of the cellular telephone device in the second state according to the present invention; 
         FIG. 8  is a view schematically showing an internal configuration of the display unit side body and an operation unit side body shown in  FIGS. 7A and 7B ; 
         FIG. 9  is a view schematically showing an internal configuration of the operation unit side body shown in  FIGS. 7A and 7B ; 
         FIG. 10A  is a cross-sectional view schematically showing a cross section of a portable wireless device having a sliding mechanism in the slid-up state; 
         FIG. 10B  is a cross-sectional view schematically showing a cross section of the portable wireless device having the sliding mechanism in the slid-down state; 
         FIG. 11A  is a cross-sectional view schematically showing a cross section of the portable wireless device having the sliding mechanism in the slid-up state; 
         FIG. 11B  is a cross-sectional view schematically showing a cross section of the portable wireless device having the sliding mechanism in the slid-down state; and 
         FIG. 12  is a cross-sectional view schematically showing a cross section of the portable wireless device having the sliding mechanism in the slid-up state. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Descriptions are provided hereinafter regarding embodiments of the present invention.  FIGS. 1 and 2  are perspective views showing an appearance of a cellular telephone device  1  as an example of the mobile terminal device according to the present invention. In addition, although the cellular telephone device  1  will be described in the present embodiments, the present invention is not limited to a cellular telephone device, and may be, for example, a PHS (Personal Handyphone System), a PDA (Personal Digital Assistant), a portable navigation device, a notebook PC or the like. 
     The cellular telephone device  1  is configured to include an operation unit side body  2  (first body) and a display unit side body  3  (second body). The operation unit side body  2  is configured to include, on a front face portion  10  thereof, an operation key set  11  and a microphone  12  to which sound produced by a user of the cellular telephone device  1  during a phone call is input. The operation key set  11  is configured with input operation keys for inputting characters such as numeric characters of a telephone number and characters of mail and the like. 
     Furthermore, the display unit side body  3  is configured with, on a front face portion  20  thereof, a display  21  for displaying a variety of information, a sound output unit  22  for outputting sound of the other party of the conversation, and a selection operation key  23  for performing selection of various operations, scrolling, etc. 
     It should be noted that the cellular telephone device  1  is also configured with other components in addition to those described above. The other components are, for example, an imaging unit configured with a CCD (Charge Coupled Device) camera, a CMOS (Complementary Metal Oxide Semiconductor) camera or the like that captures an image of a subject, a speaker that externally outputs music and the like, etc. 
     Moreover, an upper end portion of the operation unit side body  2  and a lower end portion of the display unit side body  3  are connected via a connecting portion (not illustrated) including a sliding mechanism. Therefore, the cellular telephone device  1  can freely transition between: a state in which the operation unit side body  2  and the display unit side body  3  are mutually superimposed, and the display unit side body  3  covers a top face of the operation unit side body  2  (a slid-down state, hereinafter referred to as a first state) (see  FIG. 1 ); and a state in which the display unit side body  3  is slid in a longitudinal direction in relation to the operation unit side body  2 , and a covered portion (the operation key set  11  and the microphone  12 ) of the operation unit side body  2  is exposed (a slid-up state, hereinafter referred to as a second state) (see  FIG. 2 ). 
     It should be noted that, although  FIG. 1  shows an embodiment of a sliding-type cellular telephone device, the cellular telephone device according to the present invention is not particularly limited thereto, and can be implemented as, for example, a straight shape or the like without a connecting mechanism. 
     The cellular telephone device  1  according to the present invention has a function that is compatible with a plurality of frequency bands, while securing satisfactory antenna characteristics in the first state and the second state, and employing a method in which a circuit board and a conductor in the bodies are used as a part of the antenna. 
     First Configuration 
     Here, a configuration for exhibiting the function is described. As shown in  FIG. 3 , the cellular telephone device  1  includes the operation unit side body  2 , the display unit side body  3 , a first conductive portion  2   b , a second conductive portion  3   b , a first circuit unit  2   f , and a first high-frequency cutoff unit  2   h.    
     The first conductive portion  2   b  is disposed in the operation unit side body  2 , and has a first contact point  2   a . The second conductive portion  3   b  is disposed in the display unit side body  3 , and has a second contact point  3   a.    
     The first circuit unit  2   f  has: a first ground unit  2   c , which is disposed in any one of the operation unit side body  2  and the display unit side body  3 , and which is connected to the first conductive portion  2   b  via the first contact point  2   a;  a first power supply unit  2   d  that is connected to the second conductive portion  3   b  via the second contact point  3   a ; and a first signal processing unit  2   e , which is connected to the first power supply unit  2   d , and which processes a first high frequency signal resonated by the second conductive portion  3   b.    
     A first area X overlapping with the second conductive portion  3   b  is formed in the first conductive portion  2   b . A second area Y overlapping with the first conductive portion  2   b  is formed in the second conductive portion  3   b . A first cutoff part  2   g  is connected to at least one of the first conductive portion  2   b  and the second conductive portion  3   b , and cuts off transmission of the first high frequency signal to an area X 1  toward a first end side from the first contact point  2   a  of the first area X, or to an area Y 1  toward a second end side from the second contact point  3   a  of the second area Y. In addition, the first high-frequency cutoff unit  2   h  cuts off the first high frequency signal. It should be noted that, in  FIG. 3 , although the first cutoff part  2   g  is connected to a position that cuts off transmission of the first high frequency signal to the area X 1  toward the first end side from the first contact point  2   a  of the first area X, or to the area Y 1  toward the second end side from the second contact point  3   a  of the second area Y, the present invention is not limited thereto. In place of the aforementioned configuration, the first cutoff part  2   g  may be connected to a position that cuts off transmission of the first high frequency signal to an area X 2  toward the second end side from the first contact point  2   a  of the first area X, or to an area Y 2  toward the first end side from the second contact point  3   a  of the second area Y. 
     In this way, the cellular telephone device  1  is configured to suppress mutual cancellation due to the first high frequency signal transmitted from the operation unit side body  2  side to the display unit side body  3  side; therefore, for example, even if the first conductive portion  2   b  is utilized as a ground unit of the antenna, and the second conductive portion  3   b  is utilized as a radiating element of the antenna, satisfactory antenna characteristics can be achieved without deteriorating the antenna gain. 
     First Embodiment 
     Next, a specific embodiment of the first configuration is described. As shown in  FIG. 4 , the operation unit side body  2  includes a first antenna unit  31 , a first connection part  32 , a first circuit unit  38 , and a first cutoff part  39 . 
     The first antenna unit  31  performs communication by way of a first signal S 1  modulated at first frequency. The first circuit unit  38  has: a first signal source  33 ; a first power supply unit  34  connected to the first antenna unit  31 ; a second power supply unit  35  connected to the first connection part  32 ; a first switching unit  36  that switches the first power supply unit  34  or the second power supply unit  35  to be connected to the first signal source  33 ; and a first control unit  37  that controls the first switching unit  36  to connect the second power supply unit  35  to the first signal source  33  in a case of transitioning to the second state. 
     The first cutoff part  39  is disposed between the first connection part  32  and the first circuit unit  38 , and cuts off the first signal S 1 . Furthermore, the first cutoff part  39  suppresses signals (for example, direct current signals) other than the first signal S 1  from passing therethrough. 
     The display unit side body  3  includes a second circuit unit  41 , a third circuit unit  42 , a second connection part  43 , and a second cutoff part  44 . 
     Moreover, as shown in  FIG. 4 , the second connection part  43  is disposed between the second circuit unit  41  and the third circuit unit  42 , and is connected to the first connection part  32  at high frequency in a case of transitioning to the second state. 
     The second cutoff part  44  is disposed between the third circuit unit  42  and the second connection part  43 , and cuts off the first signal S 1  transmitted via the first connection part  32  when transitioning to the second state in which the first connection part  32  and the second connection part  43  are connected at high frequency. 
     When transitioning to the second state, the second circuit unit  41  is disposed in a position that does not face the first circuit unit  38 , and performs communication by way of the first signal S 1 . 
     In addition, although shown in the example in  FIG. 4 , the first connection part  32  and the second connection part  43  are illustrated as being physically connected with each other, it is not limited thereto. For example, by forming a surface with a conductive material, the first connection part  32  and the second connection part  43  may be configured to be capacitively coupled when facing each other at a predetermined distance when the cellular telephone device  1  transitions to the second state. According to such a configuration, the first signal S 1  is transmitted from the first circuit unit  38  to the second circuit unit  41  through capacitive coupling. 
     It should be noted that, in the present embodiment, a part of the first circuit unit  38  corresponds to the first conductive portion  2   b  described above. Furthermore, the second circuit unit  41  and the third circuit unit  42  correspond to the second conductive portion  3   b  described above. Moreover, a part of the first circuit unit  38  corresponds to the first circuit unit  2   f  described above. In addition, the first connection part  32  corresponds to the first contact point  2   a  described above. Furthermore, the second connection part  43  corresponds to the second contact point  3   a  described above. Moreover, the first power supply unit  2   d  described above corresponds to a configuration when the first switching unit  36  is switched to connect the first signal source  33  and the second power supply unit  35 . In addition, the first signal S 1  corresponds to the first high frequency signal described above. Furthermore, the second cutoff part  44  or the first cutoff part  39  corresponds to the first cutoff part  2   g  described above. 
     Next, an internal configuration of the display unit side body  3  is schematically shown in  FIGS. 5A and 5B . In the display unit side body  3 , the second circuit unit  41  and the third circuit unit  42  are connected via the second cutoff part  44 . Moreover, as shown in  FIG. 5B , the second cutoff part  44  is configured with, for example, a parallel resonant circuit that is configured with a capacitor having predetermined capacity and a coil. In the present embodiment, since the second cutoff part  44  cuts off the first signal S 1 , the most part of the first signal S 1  transmitted to the second connection part  43  is transmitted to the second circuit unit  41 . In addition, since the second cutoff part  44  does not cut off signals (for example, direct current signals) other than the first signal S 1 , such signals are mutually transmitted between the second circuit unit  41  and the third circuit unit  42 . It should be noted that, in  FIG. 5A , although the second circuit unit  41  and the third circuit unit  42  are illustrated as being separate and independent, they are not limited thereto, and may be integrally configured as a single circuit unit. 
     Descriptions are provided in detail for operations of the first control unit  37  in a case of transitioning to the first state and a case of transitioning to the second state, by sliding the operation unit side body  2  and the display unit side body  3  of the cellular telephone device  1 . In the first state of the cellular telephone device  1 , the first connection part  32  and the second connection part  43  are not connected at high frequency. In this state, the first control unit  37  performs control to switch the first switching unit  36  such that the first power supply unit  34  and the first signal source  33  are electrically conductive. Therefore, in the first state, the cellular telephone device  1  communicates with external devices via the first antenna unit  31 . 
     Furthermore, in the second state of the cellular telephone device  1 , the first connection part  32  and the second connection part  43  are connected at high frequency. In this state, the first control unit  37  performs control to switch the first switching unit  36  such that the second power supply unit  35  and the first signal source  33  are electrically conductive. A high frequency signal (corresponding to the first signal S 1 ) generated in the first circuit unit  38  is transmitted to the second circuit unit  41  via the second power supply unit  35 , the first connection part  32  and the second connection part  43 . At this point in time, the first signal S 1  is cut off by the second cutoff part  44 , and thus is not transmitted to the third circuit unit  42 . 
     In this way, in the second state, the cellular telephone device  1  is configured to suppress mutual cancellation due to the first signal S 1  transmitted from the operation unit side body  2  side to the display unit side body  3  side (see  FIG. 4B ). Therefore, in the cellular telephone device  1 , even if the first circuit unit  38  is utilized as a ground unit of the antenna, and the second circuit unit  41  is utilized as a radiating element of the antenna, satisfactory antenna characteristics can be achieved without deteriorating the antenna gain. 
     It should be noted that, although a conductor for cutting off high frequency and a conductor for supplying power have been described by using a board conductor in the present embodiment, such a conductor may not be a board, and may be a shielding case or reinforcing sheet metal, and furthermore, may be an FPC board or the like used for other purposes. 
     Moreover, in the cellular telephone device  1 , a transmission path length L 1  of the first high frequency signal in the area toward the second end side from the first contact point  2   a  of the first conductive portion  2   b  is preferably substantially identical to a transmission path length L 2  of the first high frequency signal in the area toward the first end side from the second contact point  3   a  of the second conductive portion  3   b.    
     With such a configuration, in the cellular telephone device  1 , the balance between the radiating element of the antenna and the ground unit can be made satisfactory, and the deterioration of the antenna characteristics can be suppressed. 
     Second Configuration 
     In addition, as shown in  FIG. 6 , the cellular telephone device  1  may be configured to further include a second circuit unit  3   f  and a second high-frequency cutoff unit  3   h . The second circuit unit  3   f  has a second ground unit  3   c , a second power supply unit  3   d , and a second signal processing unit  3   e . The second ground unit  3   c  is disposed in any one of the operation unit side body  2  and the display unit side body  3 , and is connected to any one of the first conductive portion  2   b  and the second conductive portion  3   b  via any one of the first contact point  2   a  and the second contact point  3   a . The second power supply unit  3   d  is connected to another one of the first conductive portion  2   b  and the second conductive portion  3   b  via another one of the first contact point  2   a  and the second contact point  3   a . The second signal processing unit  3   e  is connected to the second power supply unit  3   d , and processes a second high frequency signal resonated by another one of the first conductive portion  2   b  and the second conductive portion  3   b . Furthermore, in the second configuration, the first high-frequency cutoff unit  2   h  and the second high-frequency cutoff unit  3   h  cut off the first high frequency signal and the second high frequency signal. 
     In a case in which the cellular telephone device  1  is thus configured, at least one of the first conductive portion  2   b  and the second conductive portion  3   b  is connected with a second cutoff part  3   g  that cuts off transmission of the second high frequency signal to the area X 2  toward the second end side from the first contact point  2   a  of the first area X, or to the area Y 2  toward the first end side from the second contact point  3   a  of the second area Y. 
     In this way, the cellular telephone device  1  is configured to suppress mutual cancellation due to the first high frequency signal and the second high frequency signal transmitted from the operation unit side body  2  side to the display unit side body  3  side (see  FIG. 7B ). Therefore, in the cellular telephone device  1 , for example, even if the first conductive portion  2   b  is utilized as a ground unit of a plurality of antennas, and the second conductive portion  3   b  is utilized as a radiating element of the plurality of antennas, satisfactory antenna characteristics can be achieved for each of the plurality of antennas without deteriorating the antenna gain. 
     Second Embodiment 
     Next, a specific embodiment of the second configuration is described. As shown in  FIGS. 7A ,  7 B and  8 , the operation unit side body  2  includes a second antenna unit  51 , a fourth circuit unit  57 , a third cutoff part  58 , and a fourth cutoff part  59 . 
     The second antenna unit  51  performs communication by way of a second signal S 2  modulated at second frequency. The fourth circuit unit  57  has: a second signal source  52 ; a third power supply unit  53  connected to the second antenna unit  51 ; a fourth power supply unit  54  connected to the first connection part  32 ; a second switching unit  55  that switches the third power supply unit  53  or the fourth power supply unit  54  to be connected to the second signal source  52 ; and a second control unit  56  that controls the second switching unit  55  to connect the fourth power supply unit  54  to the second signal source  52  in a case of transitioning to the second state. It should be noted that the second control unit  56  may be configured integrally with the first control unit  37 . 
     The third cutoff part  58  is disposed between the first connection part  32  and the fourth circuit unit  57 , and cuts off the first signal S 1  and the second signal S 2 . The fourth cutoff part  59  is disposed between the first circuit unit  38  and the fourth circuit unit  57 , and cuts off the first signal S 1  and the second signal S 2 . 
     In such a configuration, the first cutoff part  39  also cuts off the second signal S 2  together with the first signal S 1 . 
     Moreover, as shown in  FIGS. 7A ,  7 B and  8 , the display unit side body  3  includes a fifth cutoff part  61 . The fifth cutoff part  61  is disposed between the second circuit unit  41  and the second connection part  43 , and cuts off the second signal S 2  transmitted via the first connection part  32  when transitioning to the second state in which the first connection part  32  and the second connection part  43  are connected at high frequency. 
     In such a configuration, when transitioning to the second state, the third circuit unit  42  is disposed in a position that does not face the fourth circuit unit  57 , and performs communication by way of the second signal S 2 . 
     In addition, in the cellular telephone device  1 , a transmission path length L 3  of the second high frequency signal in the area toward the first end side from the first contact point  2   a  of the first conductive portion  2   b  is preferably substantially identical to a transmission path length L 4  of the second high frequency signal in the area toward the second end side from the second contact point  3   a  of the second conductive portion  3   b.    
     With such a configuration, in the cellular telephone device  1 , the balance between the radiating element and the ground unit in the plurality of antennas can be made satisfactory, and the deterioration of the antenna characteristics can be suppressed. 
     Moreover, in the present embodiment, the second power supply unit  3   d  described above corresponds to a configuration when the second switching unit  55  is switched to connect the second signal source  52  and the fourth power supply unit  54 . Furthermore, the second signal S 2  corresponds to the second high frequency signal described above. The fourth circuit unit  57  corresponds to the second circuit unit  3   f  described above. The first cutoff part  39  or the fifth cutoff part  61  corresponds to the second cutoff part  3   g  described above. 
     Moreover, in the cellular telephone device  1 , frequency of the first high frequency signal (the first signal S 1 ) is preferably different from frequency of the second high frequency signal (the second signal S 2 ). For example, when the frequency of the first high frequency signal is 800 MHz, and the frequency of the second high frequency signal is 2 GHz, setting is performed such that the first cutoff part  2   g  cuts off frequency at 800 MHz, and the second cutoff part  3   g  cuts off frequency at 2 GHz. By setting this way, the first high frequency signal, of which mutual cancellation is suppressed, is transmitted from the first conductive portion  2   b  to the second conductive portion  3   b;  and the second high frequency signal, of which mutual cancellation is suppressed, is transmitted from the first conductive portion  2   b  to the second conductive portion  3   b.    
     With such a configuration, the cellular telephone device  1  can implement a plurality of bands, while effectively utilizing the first conductive portion  2   b  and the second conductive portion  3   b.    
     Regarding Operations of First Control Unit  37  and Second Control Unit  56   
     Next, descriptions are provided in detail for operations of the first control unit  37  and the second control unit  56  in a case of transitioning to the first state and a case of transitioning to the second state, by sliding the operation unit side body  2  and the display unit side body  3  of the cellular telephone device  1 . 
     In the first state of the cellular telephone device  1 , the first connection part  32  and the second connection part  43  are not connected at high frequency. In this state, the first control unit  37  performs control to switch the first switching unit  36  such that the first power supply unit  34  and the first signal source  33  are electrically conductive. In addition, the second control unit  56  performs control to switch the second switching unit  55  such that the third power supply unit  53  and the second signal source  52  are electrically conductive. Therefore, in the first state, the cellular telephone device  1  communicates with external devices via the first antenna unit  31  and the second antenna unit  51 . 
     Furthermore, in the second state of the cellular telephone device  1 , the first connection part  32  and the second connection part  43  are connected at high frequency. In this state, the first control unit  37  performs control to switch the first switching unit  36  such that the second power supply unit  35  and the first signal source  33  are electrically conductive. A high frequency signal (corresponding to the first signal S 1 ) generated in the first circuit unit  38  is transmitted to the second circuit unit  41  via the second power supply unit  35 , the first connection part  32  and the second connection part  43 . At this point in time, the first signal S 1  is cut off by the second cutoff part  44 , and thus is not transmitted to the third circuit unit  42 . 
     In this way, the cellular telephone device  1  in the second state is configured to suppress mutual cancellation due to the first signal S 1  transmitted from the operation unit side body  2  side to the display unit side body  3  side (see  FIG. 7B ); therefore, even if the first circuit unit  38  and the second circuit unit  41  are utilized as radiating elements of the antenna, satisfactory antenna characteristics can be achieved without deteriorating the antenna gain. 
     Moreover, in the second state, the second control unit  56  performs control to switch the second switching unit  55  such that the fourth power supply unit  54  and the second signal source  52  are electrically conductive. A high frequency signal (corresponding to the second signal S 2 ) generated in the fourth circuit unit  57  is transmitted to the third circuit unit  42  via the fourth power supply unit  54 , the first connection part  32  and the second connection part  43 . At this point in time, the second signal S 2  is cut off by the fifth cutoff part  61 , and thus is not transmitted to the second circuit unit  41 . 
     In this way, the cellular telephone device  1  in the second state is configured to suppress mutual cancellation due to the second signal S 2  transmitted from the operation unit side body  2  side to the display unit side body  3  side (see  FIG. 7B ); therefore, even if the fourth circuit unit  57  and the third circuit unit  42  are utilized as antennas, satisfactory antenna characteristics can be achieved without deteriorating the antenna gain. 
     It should be noted that, in the example shown in  FIG. 8 , although the second circuit unit  41 , the third circuit unit  42 , the second connection part  43 , the second cutoff part  44  and the fifth cutoff part  61  are illustrated as being mounted on the circuit unit  62 , they are not limited thereto. 
     In addition, as shown in  FIG. 9 , the fourth cutoff part  59  is configured with a connecting wire (GND line  60 ) with a constant width so as to conduct direct current signals while cutting off the first signal S 1  and the second signal S 2  that are high frequency signals. With such a configuration, the cellular telephone device  1  can be configured without the fourth cutoff part  59 . 
     Regarding Configuration Shown in  FIGS. 7A and 7B  Here, the configuration shown in  FIGS. 7A and 7B  is further described in detail. The first cutoff part  39  and the third cutoff part  58  cut off, at high frequency, the fourth circuit unit  57  and the first circuit unit  38  to which a battery (not shown) is connected (the first signal S 1  and the second signal S 2  are cut off). It should be noted that, since the battery is connected to the first circuit unit  38 , GND of the first circuit unit  38  serves as reference potential. The second signal source  52  disposed in the fourth circuit unit  57  generates the second signal S 2 . Accordingly, in the cellular telephone device  1 , in order to further stabilize the second signal S 2 , a configuration is employed in which the fourth circuit unit  57  is connected to the first circuit unit  38  by way of the fourth cutoff part  59 . The fourth cutoff part  59  cuts off the first signal S 1  and the second signal S 2  in a minimum range so as not to cause any problem in terms of circuit operations. More specifically, the relationship among impedance Z 1  of the first cutoff part  39 , impedance Z 2  of the third cutoff part  58  and impedance Z 3  of the fourth cutoff part  59  is set to satisfy the following condition:
 
Condition:  Z 1= Z 2&gt; Z 3
 
     Furthermore, the configuration shown in  FIGS. 7A and 7B  can be appropriately selected in a range that is acceptable in terms of performance and cost of the cellular telephone device  1 . 
     Moreover, as shown in  FIG. 8 , the cellular telephone device  1  is configured to connect the switching units (the first switching unit  36  and the second switching unit  55 ) to the first signal source  33  and the second signal source  52 , respectively, so as to enable selection of power supply to the circuit board, in which the first connection part  32  is disposed, and to the antennas (the first antenna unit  31  and the second antenna unit  51 ). With such a configuration, in the cellular telephone device  1 , in the slid-down state (the first state), satisfactory antenna characteristics can be achieved by switching the power supply to the antennas (the first antenna unit  31  and the second antenna unit  51 ). In addition, in the cellular telephone device  1 , in the slid-up state (the second state), satisfactory antenna characteristics can be achieved by switching the power supply to the second circuit unit  41  and the third circuit unit  42 . 
     It should be noted that, although the switching units in the present embodiment are the switching unit  36  and the second switching unit  55 , they are not limited thereto, and the present invention may be configured with a branching filter. 
     Furthermore, in the present embodiment, although the fourth cutoff part  59  disposed between the fourth circuit unit  57  and the first circuit unit  38  cuts off the first signal S 1  and the second signal S 2  at high frequency, the present invention is not limited thereto. As shown in  FIG. 9 , the mobile terminal device of the present invention can achieve a similar effect by connecting the fourth circuit unit  57  and first circuit unit  38  through a thin GND line  60 , without using a high-frequency cutoff unit. By appropriately adjusting the width of the GND line  60 , the mobile terminal device of the present invention can achieve an effect similar to that in the case of using a high-frequency cutoff unit (the fourth cutoff part  59 ). 
     Moreover, although the present embodiment has been described by way of a configuration that directly connects the first connection part  32  and the second connection part  43 , the present invention is not limited thereto, and may be configured by way of capacitive coupling via a sheet metal or an antenna. 
     In addition, the electric conductor is not limited to a circuit unit (circuit board), and a speaker may be used as an antenna, or a key operation unit or the like configured with an FPC (flexible substrate) may also be used for such a purpose. Furthermore, in the present embodiment, although the first connection part  32  has been described as being disposed on a circuit board, it is not limited thereto, and the first connection part  32  may not be disposed on a circuit board. 
     EXPLANATION OF REFERENCE NUMERALS 
       1  cellular telephone device 
       2  operation unit side body 
       2   a  first contact point 
       2   b  first conductive portion 
       2   c  first ground unit 
       2   d  first power supply unit 
       2   e  first signal processing unit 
       2   f  first circuit unit 
       2   g  first cutoff part 
       2   h  first high-frequency cutoff unit 
       3  display unit side body 
       3   a  second contact point 
       3   b  second conductive portion 
       3   c  second ground unit 
       3   d  second power supply unit 
       3   e  second signal processing unit 
       3   f  second circuit unit 
       3   g  second cutoff part 
       3   h  second high-frequency cutoff unit 
       31  first antenna unit 
       32  first connection part 
       33  first signal source 
       34  first power supply unit 
       35  second power supply unit 
       36  first switching unit 
       37  first control unit 
       38  first circuit unit 
       39  first cutoff part 
       41  second circuit unit 
       42  third circuit unit 
       43  second connection part 
       44  second cutoff part 
       51  second antenna unit 
       52  second signal source 
       53  third power supply unit 
       54  fourth power supply unit 
       55  second switching unit 
       56  second control unit 
       57  fourth circuit unit 
       58  third cutoff part 
       59  fourth cutoff part 
       60  GND line 
       61  fifth cutoff part