Abstract:
Provided is a portable wireless device wherein deterioration of antenna performance is eliminated, in the case where the portable wireless device is provided with a sliding mechanism wherein a metal member is used. A sliding unit ( 150 ) includes a first sliding member ( 103 ) and a second sliding member ( 104 ), and the first case ( 101 ) and the second case ( 102 ) are slidably connected. The first sliding member ( 103 ) is in a state of metal plate, and slides with the first case ( 103 ). The second sliding member ( 104 ) is in a state of metal plate and insulated from the first sliding member ( 103 ), and slides with the second case ( 102 ) on the first sliding member ( 103 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a portable radio device. More particularly, the present invention relates to a portable radio device in which multiple casings are connected with each other in a slidable fashion and are placed in an open state and a closed state following slide operations. 
       BACKGROUND ART 
       [0002]    Conventionally, a portable radio device in which an upper casing and a lower casing are connected in a mutually slidable fashion is known. When this slide portable radio device is placed in an open state, the circuit board of the upper casing and the circuit board of the lower casing partly overlap on top of each other. Also, with a slide portable radio device, each circuit board and a metallic slide component to guide slide operations of casings are placed close to each other. Thus, in a conventional slide portable radio device, the circuit board of the upper casing and the circuit board of the lower casing are electromagnetically coupled through a slide component. As a result, with a conventional slide portable radio device, there is a problem that if an antenna is placed in the upper end side of the lower casing, the current that travels in the circuit board of the upper casing has the opposite phase to antenna current that travels in the lower casing of the circuit board, so that antenna performance is degraded. This kind of problem does not occur in a flip portable radio device in which the circuit board of the upper casing and the circuit board of the lower casing do not overlap one above the other in an open state, and therefore is specific to a slide portable radio device. 
         [0003]    To solve the above problem, a method of placing an antenna in the lower end side of the lower casing and to allow an antenna current which has the same phase as the current travelling in the circuit board of the upper casing to travel in the circuit board of the lower casing is possible (for example, patent literature 1), or a method is possible to form a slide mechanism component with an insulating resin. 
       CITATION LIST 
       [0004]    Patent Literature
   PTL1   Japanese Patent Application Laid-Open No. 2006-217572   
 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0007]    However, there is a problem that if an antenna is provided in the lower end side of the lower casing, generally, the lower end side of the lower casing is a part held by a human hand, for example, during a call, so that a human hand becomes a dielectric and degrades antenna performance. Also, there is a problem that, if a slide mechanism component is formed with a resin, compared to the case of forming a slide mechanism component with metal, the mechanical strength becomes low and provides a factor of failure. 
         [0008]    It is therefore an object of the present invention to provide a portable radio device that can prevent antenna performance degradation when a slide mechanism using a metal member is provided. 
       Solution to Problem 
       [0009]    A portable radio device employs a configuration to include: a first casing; a second casing; and a slide unit which slidably connects the first casing and the second casing, and, in this portable radio device, the slide unit has: a first slide member which is a metallic flat shape and which slides with the first casing; and a second slide member which is a metallic flat shape, which is insulated from the first slide member, and which slides with the second casing on the first slide member. 
       Advantageous Effects of Invention 
       [0010]    The present invention can prevent antenna performance degradation when a slide mechanism using a metal member is provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a side view of a portable radio device in an open state according to an embodiment of the present invention; 
           [0012]      FIG. 2  is a side view of a portable radio device in a closed state according to an embodiment of the present invention; 
           [0013]      FIG. 3  is a plan view of a portable radio device in a closed state according to an embodiment of the present invention; 
           [0014]      FIG. 4  is a plan view of a portable radio device in an open state according to an embodiment of the present invention; 
           [0015]      FIG. 5  is an A-A′ line cross sectional view of  FIG. 3 ; 
           [0016]      FIG. 6  is a back view of a slide unit according to an embodiment of the present invention; 
           [0017]      FIG. 7  is a front view of a slide unit according to an embodiment of the present invention; 
           [0018]      FIG. 8  shows a configuration which insulates between the first slide member and the second slide member according to an embodiment of the present invention; and 
           [0019]      FIG. 9  is a B-B′ line cross sectional view of  FIG. 3 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0020]    Now, the embodiment of the present invention will be explained in detail with reference to the accompanying drawings. 
       Embodiment 
       [0021]      FIG. 1  is a side view of portable radio device  100  in an open state according to an embodiment of the present invention.  FIG. 2  is a side view of portable radio device  100  in a closed state according to an embodiment of the present invention. 
         [0022]    Portable radio device  100  is mainly formed with first casing  101 , second casing  102 , first slide member  103 , second slide member  104 , circuit board  105 , display section  106 , antenna  107 , circuit board  108 , and power feeding section  109 . Also, first slide member  103  and second slide member  104  form slide unit  150 . 
         [0023]    First casing  101  is formed in a rectangular shape in a plain view and is slidably attached to second casing  102  to switch from the open state of  FIG. 1  to the closed state of  FIG. 2  or to switch from the closed state of  FIG. 2  to the open state of  FIG. 1 , by sliding with first slide member  103  of slide unit  150 . Thus, first casing  101  is attached to second casing  102  to be able to slide along the lengthwise direction of first casing  101  (a vertical direction of  FIG. 1  and  FIG. 2 ) by slide unit  150 . In the open state of  FIG. 1 , first casing  101  slides on second casing  104  with first slide member  103  that is bent to erect and, by this means, first casing  101  is held on second casing  102  in an erect state. First casing  101  has circuit board  105  and display section  106 . 
         [0024]    Second casing  102  is formed in a rectangular shape in a plan view and is slidably attached to first casing  101  to switch from the open state of  FIG. 1  to the closed state of  FIG. 2  or to switch from the closed state of  FIG. 2  to the open state of  FIG. 1 , by sliding with second slide member  104  of slide unit  150 . Also, second casing  102  has second slide member  104  and circuit board  108 . Second casing  102  has antenna  107  in the upper end part (the upper end part of  FIG. 1  and  FIG. 2 ). In an open state, second casing  102  holds first casing  101  in an erect state as shown in  FIG. 1 , and overlaps with first casing  101  in a closed state as shown in  FIG. 2 . 
         [0025]    First slide member  103  is a metallic flat shape and slides on second slide member  104  with first casing  101 . First slide member  103  is formed by bending a metal plate to erect, so that, in the open state of  FIG. 1 , first casing  101  is held in an erect state from second casing  102 . 
         [0026]    Second slide member  104  is a metallic flat shape and slides on first slide member  103  with second casing  102 . Second slide member  104  is constituted from a metal plate. 
         [0027]    Circuit board  105  is provided in first casing  101  and display section  106  such as LCD is attached. 
         [0028]    Display section  106  is, for example, a liquid crystal display apparatus (LCD) and is attached to circuit board  105 . Display section  106  shows, for example, an image data which portable radio device  100  receives. 
         [0029]    By being attached to the upper end part of circuit board  108 , antenna  107  is provided in the upper end part of second casing  102 . By this means, when the lower side of second casing  102  is held by a human hand, antenna performance degradation caused by the hand can be prevented. Antenna  107  is fed power from power feeding section  109 . 
         [0030]    Circuit board  108  is provided in second casing  102 , and antenna  107  and power feeding section  109  are provided in the upper end part. 
         [0031]    Power feeding section  109  is provided in circuit board  108  and feeds power to antenna  107 . 
         [0032]    Next, a detailed configuration of slide unit  150  will be described using  FIG. 3-FIG .  7 . 
         [0033]      FIG. 3  is a plan view of slide unit  150 .  FIG. 4  is a plan view of slide unit  150 .  FIG. 5  is an A-A′ line cross sectional view of  FIG. 3 .  FIG. 6  is a back view of slide unit  150 .  FIG. 7  is a front view of slide unit  150 . 
         [0034]    Slide unit  150  is mainly formed with first slide member  103 , second slide member  104 , coil spring  301 , non-conductive sheet  302  provided in first slide member  103 , non-conductive sheet  303  provided in second slide member  104 , wave absorber  304 , and insulation members  305  and  306 . 
         [0035]    Each configuration will be described below. 
         [0036]    First slide member  103  is formed with bottom panel part  315  of a flat shape, sidewall part  316  formed by bending diagonally upward, one lateral end part of bottom panel part  315  (a horizontal direction of  FIG. 3 ), sidewall part  317  formed by bending diagonally upward, the other lateral end of bottom panel part  315 , rail part  310  that is bent outward parallel to bottom panel part  315  from the upper end part of sidewall part  316 , rail part  311  that is bent outward parallel to bottom panel part  315  from the upper end part of sidewall part  317 . 
         [0037]    First casing  103  has stopper member  312  attached to a through hole formed in bottom panel part  315 . First casing  103  has holding member  314  attached to a through hole formed in bottom panel part  315 . 
         [0038]    Second slide member  104  is formed with top panel part  325  of a flat shape, sidewall part  326  that is formed by bending, perpendicularly downward, one perpendicular end part of second slide member  104  to a slide direction (a vertical direction of  FIG. 3 ), sidewall part  327  that is formed by bending, perpendicularly downward, the other perpendicular end part of second slide member  104  to a slide direction, bottom panel  328  that is bent inward parallel to top panel part  325  from the lower end part of sidewall part  326 , bottom panel part  329  that is bent inward parallel to top panel part  325  from the lower end part of sidewall part  327 . 
         [0039]    Second casing  104  has stopper members  322  and  323  which are attached to a through hole formed in top panel part  325 . Second casing  104  has holding member  324  which is provided in a through hole formed in top panel part  325 . 
         [0040]    Coil spring  301  is formed by winding one metal wire and is formed with engaging part  330  which engages to be movable with holding member  314  to be able to move on the outer periphery of holding member  314 , engaging part  331  which engages with holding member  324  to be able to move on the outer periphery of holding member  324 , and winding section  332  which is winded between engaging part  330  and engaging part  331 . The insulating structure with respect to engaging part  330  of holding member  314  and the insulating structure with respect to engaging part  331  of holding member  324  will be described later. 
         [0041]    Also, in coil spring  301  in the closed state of  FIG. 3 , engaging part  331  and an upper part of winding section  332  are located between bottom panel part  315  and top panel part  325 , and also engaging part  330  and a lower part of winding section  332  are exposed outside of top panel part  325 . Also, in coil spring  301  in the open state of  FIG. 4 , engaging part  330  and a lower part of winding section  332  are located between bottom panel part  315  and top panel part  325 , and also engaging part  331  and an upper part of winding section  332  are exposed outside of top panel part  325 . 
         [0042]    Also, in coil spring  301 , following slide operations of second slide member  104 , winding section  332  moves inside slide unit  150 , and holding members  314  and  324  compress winding section  332 , which makes the diameter of winding section  332  smaller. If the compression caused by holding members  314  and  324  is released, coil spring  301  is returned to the original form by elastic deformation. 
         [0043]    Non-conductive sheet  302  is sheet-shaped, and is provided on the moving trajectory of coil spring  301  which moves following slide operations in bottom panel part  315  of first slide member  103 . Non-conductive sheet  302  is provided to prevent coil spring  301  and first slide member  103  from contacting and electrically connecting, when coil spring  301  moves inside slide unit  150 . Non-conductive sheet  302  is, for example, attached to the opposite side of bottom panel part  315  from coil spring  301  by an adhesive. 
         [0044]    Non-conductive sheet  303  is sheet-shaped, and in top panel part  325  of second slide member  104  is provided on the moving trajectory of coil spring  301  which moves following slide operations. Non-conductive sheet  303  is provided to prevent coil spring  301  and second slide member  104  from contacting and electrically connecting, when coil spring  301  moves inside slide unit  150 . Non-conductive sheet  303  is, for example, attached to the opposite side of top panel part  325  from coil spring  301  by an adhesive. 
         [0045]    In bottom panel part  315  of first slide member  103 , wave absorber  304  is provided in the location where coil spring  301  is located in an open state. As the present invention, if wave absorber  304  is stuck on non-conductive sheet  302 , it is possible to prevent antenna performance degradation more. Generally, a wave absorber is made of substances which prevent a reflection of electromagnetic-wave energy by converting electromagnetic-wave energy into heat energy, or by absorbing electromagnetic-wave energy as heat energy. For example, wave absorber  304  is formed by spreading and mixing a tiny metal magnetic body into resin. For example, display section  304  is attached to non-conductive sheet  302  by an adhesive. Here, the reason wave absorber  304  is provided is that coil spring  301  which is formed by winding a metal wire material may have an electrical length to work as an antenna in the frequency band used in portable radio device  100 . Thus, wave absorber  304  absorbs electromagnetic-wave energy to prevent coil spring  301  from working as an antenna. Wave absorber  304  is not limited to a sheet shape, and it is possible to use any arbitrary shape or material as long as it can absorb electromagnetic-wave energy. It is possible to stick wave absorber  304  on non-conductive sheet  303  in addition to non-conductive sheet  302 . If wave absorber  304  is non-conductive, it is equally possible to stick wave absorber  304  instead of non-conductive sheet  302  or non-conductive sheet  303 . 
         [0046]    Insulation member  305  is constituted from an insulating material such as a resin and has a U-shaped cross section (see  FIG. 6 ). Insulation member  305  is held to second slide member by top panel part  325 , sidewall part  326 , and bottom panel part  328  of second slide member  104 . Then, held by the second slide member and mounted over rail part  310 , insulation member  305  slides in a vertical direction of  FIG. 3  with second slide member  104  on rail part  310 , guided by rail part  310 . By this means, insulation member  305  insulates first slide member  103  and second slide member  104 . The details of the insulating structure of first slide member  103  and second slide member  104  by insulation member  305  will be described later. 
         [0047]    Insulation member  306  is constituted from an insulating material such as a resin, and has a U-shaped cross section. Insulation member  306  is held to second slide member by top panel part  325 , sidewall part  327 , and bottom panel part  329  of second slide member  104 . Then, held by the second slide member and mounted over rail part  311 , insulation member  306  slides in a vertical direction of  FIG. 3  with second slide member  104  on rail part  311 , guided by rail part  311 . By this means, insulation member  306  insulates first slide member  103  and second slide member  104 . The details of the insulating structure of first slide member  103  and second slide member  104  by insulation member  306  will be described later. 
         [0048]    Rail part  310  is formed, in first slide member  103 , parallel to the lengthwise direction of first slide member  103  and the slide direction of second slide member  104 . 
         [0049]    Rail part  311  is formed, in first slide member  103 , parallel to the lengthwise direction of first slide member  103  and the slide direction of second slide member  104 . 
         [0050]    Stopper member  312  is held in a through hole formed in first slide member  103 , in a state sticking out toward second slide member  104 . Also, by engaging with stopper member  322 , stopper member  312  restricts movement in the closing direction (upward in  FIG. 3  and  FIG. 5 ) of second slide member  104  (see  FIG. 5 ). 
         [0051]    Stopper member  313  is held in a through hole formed in first slide member  103 , in a state sticking out toward second slide member  104 . Also, by engaging with a stopper member (not shown) provided in second slide member  104 , stopper member  313  restricts movement in a closing direction (upward in  FIG. 3 ) of second slide member  104 . 
         [0052]    Holding member  314  is cylindrical, and engaging part  330  of coil spring  301  is winded around its outer peripheral surface and also engages with engaging part  330  to be able to move along its outer peripheral surface when coil spring  301  moves following slide operations. 
         [0053]    Bottom panel part  315  is parallel to a moving plane where coil spring  301  moves following slide operations of second slide member  104  with respect to first slide member  103 . In bottom panel part  315 , wave absorber  302  is provided on the moving trajectory of coil spring  301 . 
         [0054]    Stopper member  322  is held in a through hole formed in first slide member  104 , in a state sticking out toward second slide member  103 . Also, by engaging with stopper member  312 , stopper member  322  restricts movement to a closed direction (upward in  FIG. 3 ) of second slide member  104 . 
         [0055]    Stopper member  323  is held in a through hole formed in first slide member  103 , in a state sticking out toward second slide member  104 . Also, by engaging with a stopper member (not shown) provided in first slide member  103 , stopper member  323  restricts movement to a closed direction of second slide member  104 . 
         [0056]    Holding member  324  is cylindrical, and engaging part  331  of coil spring  301  is winded around its outer peripheral surface, and also engages with engaging part  330  to be able to move along its outer peripheral surface when coil spring  301  moves following slide operations. 
         [0057]    Top panel part  325  is parallel to a moving plane on which coil spring  301  moves following slide operations of first slide member  103  with respect to second slide member  104 . 
         [0058]    The description of each configuration of unit  150  has been done in the above. 
         [0059]    Next, a configuration to insulate first slide member  103  and second slide member  104  will be described using  FIG. 8 .  FIG. 8  shows a configuration to insulate first slide member  103  and second slide member  104 . 
         [0060]    In  FIG. 8 , insulation member  305  is held to second slide member by top panel part  325 , sidewall part  326 , and bottom panel part  328  of second slide member  104 . Also, insulation member  305  has groove part  801  which slidably engages with rail part  310 . Groove part  801  is provided to extend along a slide direction of second slide member  104 . 
         [0061]    By this means, first slide member  103  and second slide member  104  slides through insulation member  305 , and are mutually insulated upon slide operations. 
         [0062]    Now, the same applies to holding member  306  and the description will be omitted. 
         [0063]    Next, a configuration to insulate coil spring  301  and first slide member  103  will be described using  FIG. 9 .  FIG. 9  is a B-B′ line cross sectional view of  FIG. 3 . 
         [0064]    In  FIG. 9 , holding member  314  is made by a metal material, substantially cylindrical, and also attached to first slide member  103  by being pressed into through hole  902  formed in bottom panel part  315  of first slide member  103 . In holding member  314 , caulking part  920  is formed in an upper part to prevent insulation member  901  from loosening upward. 
         [0065]    Insulation member  901  is attached to a periphery of holding member  314 . Insulation member  901  has main unit part  910 , upper flange  911  that is provided in an upper end part and that stretches outward from insulation member  910 , and flange part  912  that is provided in a lower end part and that stretches outward from insulation member  910 . 
         [0066]    By engaging with main unit part  910  of insulation member  901 , engaging part  330  of coil spring  301  is prevented from loosening upward and downward by upper flange part  911  and lower flange part  912  and also is kept by insulation member  901 . Held by insulation member  901 , engaging part  330  of coil spring  301  engages with insulation member  901  to be able to move along the periphery of main unit part  910  with the movement of coil spring  301 . 
         [0067]    Now, the same applies to holding member  324  and the description will be omitted. 
         [0068]    Next, the operations of slide unit  150  will be described. 
         [0069]    At first, the operation to switch from a closed state to an open state will be described. 
         [0070]    In the state of  FIG. 2 , if a user slides first casing  101  upward in  FIG. 2 , first slide member  103  slides upward in  FIG. 3  to second slide member  104 . Specifically, insulation member  305  slides along rail part  310  and also insulation member  306  slides along rail part  311 . 
         [0071]    Following slide operations, in coil spring  301 , winding section  332  is compressed by holding members  314  and  324 , and moves between non-conductive sheet  302  and non-conductive sheet  303  by reducing its diameter by elastic deformation. 
         [0072]    Next, when first slide member  103  slides to some extent, the compression caused by holding members  314  and  324  is released, so that coil spring  301  is returned to the original form. The returning force of coil spring  301  on returning to the original form energizes first slide member  103  in an end direction of a slide (upward in  FIG. 3 ). 
         [0073]    Next, stopper member  322  and stopper member  323  of second slide member  104  engages with a stopper member (not shown) provided in first slide member  103 , so that first slide member  103  stops the slide operations and be in an open state (the states of  FIG. 1  and  FIG. 4 ). In this case, coil spring  301  is located between non-conductive sheet  302  and wave absorber  304 , and non-conductive sheet  303 . Also, a user communicates by, for example, making a telephone call in this state. 
         [0074]    Next, the operation to switch from an open state to a closed state will be described. 
         [0075]    In the state of  FIG. 1 , if the user slides first casing  101  downward in  FIG. 1 , first slide member  103  slides downward with respect to second slide member  104 . Specifically, insulation member  305  slides along rail part  310  and also insulation member  306  slides along rail part  311 . 
         [0076]    In association with the initial operations of the above slide operations, in coil spring  301 , winding section  332  is compressed by holding members  314  and  324 , and moves between non-conductive sheet  302  and non-conductive sheet  303  by reducing its diameter by elastic deformation. 
         [0077]    Next, when first slide member  103  slides to some extent, the compression caused by holding members  314  and  324  is released, so that coil spring  301  is returned to the original form. A returning force caused by coil spring  301  on returning to the original form, first slide member  103  energizes in an end direction of a slide (downward in  FIG. 4 ). 
         [0078]    Next, stopper member  322  of second slide member  104  engages with stopper member  312  of first slide member  103 , and also stopper member  323  of second slide member  104  engages a stopper member (not shown) provided in first slide member  103 , so that first slide member  103  stops slide operations and is placed in a closed state (the states of  FIG. 2  and  FIG. 3 ). 
         [0079]    Incidentally, as the present embodiment, in a case where first casing  101  is held in an erect state with respect to second casing  102 , it is necessary to bend and erect the rail to guides the slides, and in a structure only providing metal rails at both ends of casing, the rail itself is thin, so that it is difficult to bend and erect the rail accurately. Thus, as the present invention, by forming a slide unit by first slide member  103  shaped in a metal plate and second slide member  104 , it is possible to bend the rail to erect accurately and easily. 
         [0080]    Therefore, by insulating the first slide member and the second slide member and insulating a coil spring of the first slide member or a coil spring of the second slide member, the present embodiment can prevent antenna performance degradation when a slide mechanism using a metal member is provided. Also, according to the present embodiment, circuit boards do not electromagnetically couple with each other through a slide unit, so that miniaturization and thinning are possible. The present embodiment provides a wave absorber on the moving trajectory of a coil spring and consequently a coil spring functions as an antenna, so that it is possible to prevent antenna performance degradation. The present embodiment can make a portable radio device thinner by making a wave absorber a sheet shape. 
         [0081]    Although with the present embodiment coil spring  301  is insulated from both first slide member  103  and second slide member  104 , the present invention is not limited to this, and it is possible to achieve the effect of the present invention by insulating coil spring  301  from at least one of first slide member  103  and second slide member  104 . Although with the present embodiment a wave absorber is provided in first slide member  103 , the present invention is not limited to this, and it is equally possible to provide a wave absorber in second slide member  104 . Although with the present embodiment first casing  101  slides as erecting from second casing  102  and switches from a closed state and an open state, the present invention is not limited to this, first casing  101  may slide from a closed state to an open state, and that, a slide structure may apply an arbitrary method. Although with the present embodiment insulation members  305  and  306  which insulate first slide member  103  and second slide member  104  are provided in second slide member  104 , the present invention is not limited to this, and it is equally possible to provide insulation members  305  and  306  in first slide member  103 . 
         [0082]    The disclosure of Japanese Patent Application No. 2008-334009, filed on Dec. 26, 2008 including the specification, drawings and abstract, is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0083]    A portable radio device of the present invention is especially suitable to connect a plurality of casings in a mutually slidable fashion and which is placed them in an open state and a closed state in response to slide operations.