Abstract:
A foldaway electronic device includes a base unit having opposing lateral surfaces and an end portion, a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit, a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position, a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position, and impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated, wherein either lateral surface of the base unit has a guard portion that extends over and prevents contact by a user&#39;s thumb and fingers with a portion of the corresponding lateral surface of the cover unit when the cover unit is in the folded position and the lock release mechanism is being actuated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to electronic devices and flexible cables for same, and more particularly, to a foldaway portable electronic device such as a communications device and flexible cable configured so that the electronic device is folded when not in use and is opened automatically at the push of a button when in use and communications conducted.  
           [0003]    2. Description of the Related Art  
           [0004]    In terms of their structure, portable communications devices may be divided into two main types, one capable of being folded and the other, having a generally oblong shape, not capable of being folded. The former type can be further divided into two sub-types, that is, those that are opened manually and those that are opened automatically by pushing a button.  
           [0005]    Portable communications devices capable of being folded are markedly more compact in their, folded state than are those portable communications devices which cannot be folded, and so are easy to store and to carry. Also, users of such portable communications devices are often engaged in some other task while using the device, so a construction that allows the user to open the portable communications device using one hand, that is, by the push of a button, is handy and desirable.  
           [0006]    [0006]FIGS. 1A and 1B show an example of a conventional portable communications device  10  which can be opened automatically. This portable communications device  10  consists of a substantially rectangular key pad base unit  11 , a substantially rectangular display cover unit  12 , and a hinge  13  that connects the key pad base unit  11  with the display cover unit  12 .  
           [0007]    The key pad base unit  11  includes operating keys  14  and a microphone  15 . The display cover unit  12  has a liquid crystal panel  16  for the display, an antenna  17  and a speaker  18 . A hinge module  19  is incorporated inside the hinge  13 . The hinge module  19  springingly impels the display cover unit  12  away from the key pad base unit  11 . A button  20  is provided near the hinge  13  at a lateral surface  11 a of the key pad base unit  11 .  
           [0008]    Normally, the portable communications device  10  is closed as shown in FIG. 1A, with the display cover unit  12  closed and joined to the key pad base unit  11  by a lock tab  21 .  
           [0009]    When in use, that is, when conducting communications, the user grasps the foldaway portable communications device  10  by taking the key pad unit  11  in the palm of the left hand  30  and pressing the button  20  with the thumb  31  of the left hand. In so doing, a rotating lever  22  shifts the lock tab  21 , causing the lock tab  21  to withdraw and thereby releasing the display unit  12  from the key pad base unit  11 . A spring inside the hinge module  19  causes the display unit  12  to rotate away from the key pad base unit  11  and into the unfolded position shown in FIG. 1B. The user then puts the portable communications device  10  to the ear and conducts communications.  
           [0010]    However, partly because the portable communications devices like the portable communications device  10  shown in FIGS. 1A and 1B have becom more compact, when th user presses the button  20  with the thumb  31  of the left hand  30  a part of the thumb  31  tends to contact a side  12   a  of the display cover unit  12 , while the fingers  32  tend to contact an opposite side  12   b  of the display cover unit  12 .  
           [0011]    In such a state, the thumb and fingers contacting the sides  12   a ,  12   b  of the display cover unit  12  create resistance against, and thus hamper the smooth opening of, the display cover unit  12 .  
         SUMMARY OF THE INVENTION  
         [0012]    Accordingly, it is a general object of the present invention to provide an improved and useful foldaway electronic device and flexible cable for same in which the above-described disadvantage is eliminated.  
           [0013]    The above-described object of the present invention is achieved by a foldaway electronic device comprising:  
           [0014]    a base unit having opposing lateral surfaces and an end portion;  
           [0015]    a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit;  
           [0016]    a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position;  
           [0017]    a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position; and  
           [0018]    impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated,  
           [0019]    wherein either lateral surface of the base unit has a guard portion that extends over and prevents contact with a portion of the corresponding lateral surface of the cover unit by a user&#39;s thumb, and fingers when the cover unit is in the folded position and the lock release mechanism is being actuated.  
           [0020]    The above-described object of the present invention is also achieved by A foldaway electronic device comprising:  
           [0021]    a base unit having opposing lateral surfaces and an end portion;  
           [0022]    a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit;  
           [0023]    a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position;  
           [0024]    a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position;  
           [0025]    impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated; and  
           [0026]    an operating member for operating the lock release mechanism comprising:  
           [0027]    a pedestal member provided on a lateral surface of the base unit so as to project beyond a corresponding lateral surface of the cover unit; and  
           [0028]    a button provided on the pedestal member in such a way that when the button is depressed the pedestal portion prevents contact with a portion of the corresponding lateral surface of the cover unit by a user&#39;s thumb when the cover unit is in the folded position and the lock release mechanism is being actuated.  
           [0029]    Additionally, the above-described object of the present invention is also achieved by a foldaway electronic device comprising:  
           [0030]    a base unit having opposing lateral surfaces and an end portion;  
           [0031]    a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end, portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit;  
           [0032]    a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position;  
           [0033]    a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position;  
           [0034]    impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated; and  
           [0035]    an operating member for operating the lock release mechanism, the operating member being provided on a lateral surface of the base unit,  
           [0036]    a lateral surface of the cover unit corresponding to the lateral surface of the base unit on which the operating member is provided having a substantially concave shape with respect to the lateral surface of the base unit at least in a vicinity of the operating member.  
           [0037]    Additionally, the above-described object of the present invention is also achieved by a foldaway electronic device comprising:  
           [0038]    a base unit having opposing lateral surfaces and an end portion;  
           [0039]    a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit;  
           [0040]    a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position;  
           [0041]    a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position;  
           [0042]    impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated; and  
           [0043]    an operating member for operating the lock release mechanism, the operating member being provided on a lateral surface of the base unit,  
           [0044]    the base unit having a width at least of a portion where the operating member is provided greater than a width of a corresponding portion of the cover unit.  
           [0045]    According to the invention described above, the cover unit is not restricted by the thumb and fingers of the user&#39;s hand and can thus open smoothly.  
           [0046]    The above-described object of the present invention is also achieved by a foldaway electronic device comprising:  
           [0047]    a base unit having opposing lateral surfaces and an end portion;  
           [0048]    a cover unit having opposing lateral surfaces, each of which corresponds to one of the lateral surfaces of the base unit, and an end portion that is rotatably attached to the end portion of the base unit, whereby the cover unit may be rotated between a folded position relative to the base unit and an unfolded position relative to the base unit;  
           [0049]    a locking mechanism in the base unit and cover unit that locks the cover unit in the folded position;  
           [0050]    a lock release mechanism in the base unit that releases the locking mechanism when the cover unit is in the folded position;  
           [0051]    impelling means in the base unit for impelling the cover unit from the folded position to an unfolded position after the lock release mechanism has been actuated;  
           [0052]    an operating member for operating the lock release mechanism, the operating member being provided on a lateral surface of the base unit; and  
           [0053]    a coaxial-type flexible cable extending between the base unit and the cover unit via the respective end portions thereof,  
           [0054]    the coaxial-type flexible cable comprising a flexible cable and a coaxial cable laid on and affixed to the flexible cable, the coaxial-type flexible cable being wound within the hinge in such a way as to impel the cover unit apart from the base unit into an unfolded position.  
           [0055]    According to the invention described above, the elasticity of that portion of the coaxial flexible cable that forms the loop rotatably impels the cover unit open, supplementing a force supplied by a coil spring to be described later and thus allowing use of a coil spring having a torsional force smaller than usual.  
           [0056]    Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0057]    [0057]FIGS. 1A and 1B are diagrams showing a conventional foldaway portable communications device in a closed and an unfolded position, respectively;  
         [0058]    [0058]FIGS. 2A and 2B are diagrams showing a foldaway portable communications device according to an embodiment of the present invention in a closed and an unfolded position, respectively;  
         [0059]    [0059]FIGS. 3A, 3B and  3 C are diagrams showing top, side and rear views, respectively, of the portable communications device shown in FIGS. 2A and 2B;  
         [0060]    [0060]FIG. 4 is a diagram showing a cross-sectional view along a line IV-IV shown in FIG. 3A;  
         [0061]    [0061]FIG. 5 is a diagram showing a cross-sectional view along a line V-V shown in FIG. 3A;  
         [0062]    [0062]FIG. 6 is a diagram showing an exploded view of the hinge and the lock mechanism of the portable communications device according to an embodiment of the present invention;  
         [0063]    [0063]FIGS. 7A, 7B and  7 C are diagrams showing side, top and side views, respectively, of the hinge and lock mechanism;  
         [0064]    [0064]FIGS. 8A, 8B and  8 C are diagrams showing top, front and side views, respectively, of the lock member;  
         [0065]    [0065]FIGS. 9A, 9B and  9 C are diagrams showing cross-sectional views along lines A-A, C-C and B-B shown in FIG. 7B, respectively;  
         [0066]    [0066]FIGS. 10A, 10B,  10 C and  10 D are diagrams showing cross-sectional views along lines D, E, F and G as shown in FIG. 7B, respectively;  
         [0067]    [0067]FIGS. 11A, 11B,  11 C and  11 D are diagrams showing cross-sectional views along lines H, I, J and K as shown in FIG. 7B, respectively;  
         [0068]    [0068]FIGS. 12A, 12B and  12 C are diagrams showing top, side and rear views of a coaxial flexible cable according to an embodiment of the present invention;  
         [0069]    [0069]FIG. 13 is a diagram showing the structure of the coaxial flexible cable shown in FIGS. 12A, 12B and  12 C;  
         [0070]    [0070]FIGS. 14A, 14B,  14 C and  14 D are diagrams showing cross-sectional views along lines A, B, C and F, respectively;  
         [0071]    [0071]FIGS. 15A and 15B are diagrams showing a foldaway portable communications device according to a second embodiment of the present invention, in a closed and an unfolded position, respectively;  
         [0072]    [0072]FIGS. 16A and 16B are diagrams showing a foldaway portable communications device according to a second embodiment of the present invention, in a closed and an unfolded position, respectively;  
         [0073]    [0073]FIGS. 17A and 17B are diagrams showing a variation of a lock mechanism and a lock release mechanism;  
         [0074]    [0074]FIGS. 18A, 18B and  18 C are diagrams showing top, side and rear views, respectively, of a first variation of the coaxial flexible cable;  
         [0075]    [0075]FIG. 19 is a diagram showing the structure of the coaxial flexible cable shown in FIGS. 18A, 18B and  18 C;  
         [0076]    [0076]FIGS. 20A, 20B,  20 C and  20 D are diagrams showing cross-sectional views of the coaxial flexible cable shown in FIG. 18A along lines A, B, C and E, respectively; and  
         [0077]    [0077]FIGS. 21A and 21B are diagrams showing a sid and an expanded cross-sectional view along a line B-B, respectively, of the second variation of the coaxial flexible cable. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0078]    A description will how be given of embodiments of the present invention, with reference to the accompanying drawings.  
         [0079]    It should be noted that identical or corresponding elements in the embodiments are given identical or corresponding reference numbers in all drawings, and detailed descriptions thereof are omitted. Moreover, where relevant, for ease of explanation directions in the drawings are given as X 1 -X 2  for the side-to-side direction, Y 1 -Y 2  for front-to-back direction, and Z 1 -Z 2  for the vertical direction.  
         [0080]    [0080]FIGS. 2A and 2B are diagrams showing a foldaway portable communications device according to an embodiment of the present invention in a closed position and an unfolded position, respectively. FIGS. 3A, 3B and  3 C are diagrams showing top, side and rear views, respectively, of the portable communications device shown in FIGS. 2A and 2B.  
         [0081]    It should be noted that the term “foldaway” as used herein is defined as that which can be folded together for easy storage and portability.  
         [0082]    As shown in the diagrams, the foldaway portable communications device  50  has a lock-release button. When the button is pushed the portable communications device  50  automatically opens.  
         [0083]    [0083]FIGS. 2A, 3A,  3 B and  3 C show the portable communications device  50  in a folded position. The two-dotted chain lines show the left hand  30  of a user supporting the portable communications device  50  with the latter in a folded position and the user attempting to release the lock and open the portable communications device  50 .  
         [0084]    [0084]FIG. 2B shows a state in which the portable communications device  50  is open for communications, in a state in which the user supports the portable communications device  50  with the left hand  30 , indicated by the two-dotted chain line. A hinge  53  lies along the horizontal X 1 -X 2  axis.  
         [0085]    As shown in FIGS. 2A, 2B,  3 A,  3 B and  3 C, the portable communications device  50  comprises a substantially rectangular key pad base unit  51 , a substantially rectangular display cover unit  52  that is movable with respect to the key pad base unit  51 , and a hinge  53  that connects the key pad base unit  51  with the display cover unit  52 .  
         [0086]    Further, the rectangular key pad base unit  51  has guard portions  54 ,  55 , a lock release button  56 , an operating key  57  and a microphone  58 . The display cover unit  52  has a liquid crystal panel  59  as a display, an antenna  60  and a speaker  61 .  
         [0087]    The display cover unit  52  is locked in a folded position to be described later, and, further, is impelled to an unfolded position in a direction away from the key pad base unit  51  by a spring, in a process to be described later.  
         [0088]    Normally, the portable communications device  50  is, as shown in FIG. 2A, in a folded position, that is, in a state in which the display cover unit  52  is closed, that is, folded, atop the key pad base unit  51 . When the portable communications device  50  is to be used, the user ordinarily supports the portable communications device  50  by the key pad base unit  51  in the left hand  30  and uses the thumb  31  of the left hand to press the lock release button  56 . In so doing, the display cover unit  52  is unlocked and a spring disposed insid the hinge  53  rotatably impels the display cover unit  52  away from the key pad base unit  51  in the A 1  direction, to the unfolded position shown in FIG. 2B.  
         [0089]    [0089]FIG. 4 is a diagram showing a cross-sectional view of the folded closed portable communications device  50  along a line IV-IV shown in FIG. 3A. FIG. 5 is a diagram showing a cross-sectional view of the folded closed portable communications device  50  along a line V-V shown in FIG. 3A. FIG. 6 is a diagram showing an exploded view of the hinge  53  and the lock mechanism of the portable communications device  50  in an unfolded position. FIGS. 7A, 7B and  7 C are diagrams showing side, top and side views, respectively, of the hinge  53  and lock mechanism of the portable communications device  50 . FIGS. 8A, 8B and  8 C are diagrams showing top, front and side views, respectively, of the lock member and the lock release button. FIGS. 9A, 9B and  9 C are diagrams showing cross-sectional views along lines A-A, C-C and B-B shown in FIG. 7B, respectively. FIGS. 10A, 10B,  10 C and  10 D are diagrams showing cross-sectional views along lines D, E, F and G as shown in FIG. 7B, respectively.  
         [0090]    It should be noted that the key pad base unit  51  comprises chiefly a substantially box-like housing  62  and a cover  63 . A printed circuit board  64  for mounting various electronic parts is mounted within the box-like structure formed by the housing  62  and the cover  63 . Similarly, the display cover unit  52  comprises chiefly a box-like housing  65  and a cover  66 , with another printed circuit board  67  for mounting various electronic parts contained therein.  
         [0091]    A description will now be given of the guard portions  54 ,  55 . This description, where it may reference only one of the two guard portions  54 ,  55 , applies equally to both such guard portions  54 ,  55 .  
         [0092]    As shown in FIGS. 2A, 2B,  3 A,  3 B,  3 C,  4 ,  5 ,  6 ,  7 A,  7 B and  7 C, the guard portion  54  is disposed on an X 2  lateral surface  51   a  of the key pad base unit  51  (specifically the housing  62  thereof) so as to project outwardly in the X 2  direction from the lateral surface  51   a  of the key pad base unit  51  near the hinge  53 , in such a way as to extend above a top surface of the key pad base unit  51  in a Z 1  direction as well as beyond a rear edge of the key pad base unit  51  in a Y 1  direction. For the sake of descriptive convenience, that part of the guard portion  54  that projects above the top surface of the key pad base unit  51  in a Z 1  direction is referred to hereinafter as projecting portion  54   z   1 , and, similarly, that part of the guard portion  54  that projects beyond the rear edge of the key pad base unit  51  in a Y 1  direction is referred to hereinafter as projecting portion  54   y   1 . When the portable communications device  50  is folded closed the projecting portion  54   z   1  covers a portion of an X 2  lateral surface  52   a  of the display cover unit  52 .  
         [0093]    It should be noted that, as will be described in more detail later, an inner lateral surface of the projecting portion  54   z   1  does not contact the lateral surface  52   a  of the display cover unit  52 . Instead, as shown for example in FIGS. 4 and 5, a slight gap  68  exists between the inner lateral surface of the projecting portion  54   z   1  and the lateral surface  52   a  of the display cover unit  52 .  
         [0094]    Likewise, guard portion  55  has a structure identical to that of guard portion  54 , though located instead on an X 1  lateral surface  51   b  of the key pad base unit  51  (specifically the housing  62 ), extending in the Z 1  and Y 1  directions and projecting in the X 1  direction as well.  
         [0095]    Similarly, that part of the guard portion  55  that projects above the top surface of the key pad base unit  51  in a Z 1  direction is referred to hereinafter as projecting portion  55   z   1 , and, similarly, that part of the guard portion  55  that projects beyond the rear edge of the key pad base unit  51  in a Y 1  direction is referred to hereinafter as projecting portion  55   y   1 . When the portable communications device  50  is folded closed the projecting portion  55   z   1  covers a portion of an X 1  lateral surface  52   b  of the display cover unit  52 .  
         [0096]    Additionally, similarly, it should be noted that, as will be described in more detail later, an inner lateral surface of the projecting portion  55   z   1  does not contact the lateral surface  52   b  of the display cover unit  52 . Instead, as shown for example in FIGS. 4 and 5, a slight gap  69  exists between the inner lateral surface of the projecting portion  55   z   1  and the lateral surface  52   b  of the display cover unit  52 .  
         [0097]    It should be noted that the key pad base unit  51  has a width at the location of the guard portions  54 ,  55  that is wider than a width of the display cover unit  52  at the same location. It should be further noted that the width dimensions mentioned here run in the X 1 -X 2  direction, parallel to the hinge  53 .  
         [0098]    As a result, the guard portion  54  keeps the user&#39;s thumb  31  from contacting the lateral surface  52   a  of the display cover unit  52  when the user takes the folded portable communications device  50  into the left hand  30 , supports the portable communications device  50  by the key pad base unit  51  and presses the lock release button  56  with the thumb  31  of the left hand  30  in order to activate the portable communications device  50  and establish communications. The other guard portion  55  similarly prevents the fingers  32  of the left hand  30  from contacting the lateral surface  52   b  of the display cover unit  52  on the opposite side  55 . Accordingly, the display cover unit  52  can unfold and open without being restricted by the thumb and fingers  31 ,  32  of the user and can thus open smoothly.  
         [0099]    A description will now be given of a lock mechanism  70  and a lock release operating mechanism  77 . The two parts are intimately related and thus will be described not separately but in tandem.  
         [0100]    [0100]FIG. 6 shows an exploded view of the hinge and the lock mechanism  70  of the portable communications device according to an embodiment of the present invention. FIGS. 7A, 7B and  7 C are diagrams showing side, top and side views, respectively, of the hinge  53  and lock mechanism  70 . FIGS. 8A, 8B and  8 C are diagrams showing top, front and side views, respectively, of the lock release button member  71  which forms a part of the lock mechanism  70 .  
         [0101]    As shown in the diagrams, an interior of the guard portion  54  on the lateral surface  51   a  on the X 2  side of the key pad base unit  51  comprises an empty space  54   a . The interior space  54   a  is utilized to insert and provide the lock mechanism  70  and the lock release operating mechanism  77 .  
         [0102]    More specifically, the interior space  54   a  contains the lock release button member  71 , a shaft  72 , a compression coil spring  73  and a cover member  74  as shown in FIGS. 8A, 8B and  8 C.  
         [0103]    The cover member  74  is engaged between the key pad base unit  51  and the guard portion  54  and fixedly mounted by a screw  75  on the Y 2  edge thereof, thus covering an opening on the X 1  side of the interior space  54   a  of the guard portion  54 .  
         [0104]    The lock release button member  71  itself comprises a bearing  71   a , arms  71   b  and  71   c  extending from both ends of the bearing  71   a , a hook  71   d  at a tip end of arm  71   b , and the lock release button  56  at a tip end of arm  71   c.    
         [0105]    The lock release button member  71  is supported on the bearing  71   a  by a vertical shaft  72  in the guard portion  54  and extends in the Y 1 -Y 2  lateral direction. The lock release button  56  engages an opening  54   b  in a lateral surface of the guard portion  54  and exposed externally. The hook  71   d  projects outward in the X 1  direction beyond a notched portion  74   b  formed in the cover member  74 . The lock release button member  71  is impelled by the compression coil spring  73  in a B 1  direction as shown in FIG. 6.  
         [0106]    It will be appreciated that the lock release button  56  is positioned not concentrically with a hypothetical axis CL 53  of the hinge  53  but at a position offset from such axis CL 53  by a distance “a” in the forward Y 2  direction, so as to be disposed not on but near the hinge  53 .  
         [0107]    The hook  71   d  is positioned slightly above a top surface of the key pad base unit  51 , and, as previously mentioned, projects outward in the lateral X 1  direction so as to engage a concavity  52   a   1  formed in the lateral surface  52   a  of the display cover unit  52 , the concavity  52   a   1  disposed opposite-the hook  71   d  when the portable communications device is folded closed. The engagement of the hook  71   d  with the concavity  52   a   1  locks the display cover unit  52  to the key pad base unit  51  in a folded position such as that shown, for example, in FIG. 2A.  
         [0108]    When the lock release button  56  is pressed, the lock release button member  71  is rotated in the direction of arrow B 2  and the hook  71   d  is thus drawn into the interior space  54   a  and away from the concavity  52   a   1 , thus releasing the lock on the display cover unit  52  and thereby permitting the display cover unit  52  to swing open for use.  
         [0109]    The lock mechanism  70  has the arm-like lock release button member  71  and therefore has a relatively unwieldy structure. Nevertheless the interior space  54   a  enclosed within the guard portion  54  accommodates the lock mechanism  70 , so the compactness of the portable communications device  50  is not affected.  
         [0110]    The lock release button member  71   d , the concavity  52   a   1  in the display cover unit  52  and the compression coil spring  73  together form the lock mechanism  70 .  
         [0111]    The lock release button member  71  bearing  71   a , the arms  71   b ,  71   c  extending from both ends of the bearing  71   a , and the lock release button  56  provided at the tip of the arm  71   c  together form the lock release operating mechanism  77 .  
         [0112]    A description will now be given of the hinge  53 , with reference to FIGS. 6, 9A,  9 B,  9 C,  10 A,  10 B,  10 C,  10 D,  11 A,  11 B,  11 C and  11 D.  
         [0113]    [0113]FIGS. 9A, 9B and  9 C are diagrams showing cross-sectional views along lines A-A, C-C and B-B shown in FIG. 7B, respectively. FIGS. 10A, 10B,  10 C and  10 D are diagrams showing cross-sectional views along lines D, E, F and G as shown in FIG. 7B, respectively. FIGS. 11A, 11B,  11 C and  11 D are diagrams showing cross-sectional views along lines H, I, J and K as shown in FIG. 7B, respectively.  
         [0114]    As shown in the diagrams, the housing  65  of the display cover unit  52  is shaped at the location of the hinge  53  in such a way as to have, in order from the X 2  side to the X 1  side thereof, a cylindrical portion  65   a , a semi-cylindrical portion  65   b , a notched portion  65   c  and another cylindrical portion  65   d . The housing  62  of the key pad base unit  51  is shaped at the location of the hinge  53  in such a way as to have, in order from the X 2  side to the X 1  side thereof, a projecting portion  54   y   1 , a notched portion  62   a , a semi-cylindrical portion  62   b , a notched portion  62   c , and a projecting portion  55   y   1 .  
         [0115]    The cylindrical portion  65   a  and the semi-cylindrical portion  65   b  engage the notched portion  62   a , the semi-cylindrical portion  62   b  engages the notched portion  65   c  and the cylindrical portion  65   d  engages the notched portion  62   c . Additionally, the semi-cylindrical portion  66   a  of the cover  66  is disposed opposite and corresponds to semi-cylindrical portion  65   b , the two semi-cylindrical portions  66   a  and  65   b  together forming a cylindrical portion  80 . Similarly, the semi-cylindrical portion  63   a  of the cover  63  is disposed opposite semi-cylindrical portion  62   b , the two semi-cylindrical portions  63   a  and  62   b  together forming a cylindrical portion  81 . The cylindrical portions  80 ,  81  thus formed are adjacent to and abut each other.  
         [0116]    A shaft member  82  engaging a torsion coil spring  83  is disposed inside the cylindrical portion  65   a . A squared portion  82   a  of the shaft member  82  engages a squared aperture  54   c  formed in the projecting portion  54   y   1 . The torsion coil spring  83  engages the shaft member  82  and is contained within the interior of the cylindrical portion  65   a , the X 2  end  83   a  of the torsion coil spring  83  being engaged by the shaft member  82  and the X 1  end  83   b  of the torsion coil spring  83  being twisted in a clockwise direction as viewed looking toward the X 1  side and engaged by an inside of the cylindrical portion  65   a . An E-shaped washer  84  is fixedly engaged at the tip of the squared portion  82   a  of the shaft member  82 . A cap  85  is fixedly engaged to an aperture  54   d  of the projecting portion  54   y   1 .  
         [0117]    A damper unit  86  is provided inside the cylindrical portion  65   d , with a case  86   a  of the damper unit  86  being fixedly mounted to the cylindrical portion  65   d . A squared shaft portion  86   b  of the damper unit  86  engages and is secured by a square aperture  55   b  formed in the projecting portion  55   y   1 . An E-shaped washer  87  is fixedly engaged at the tip of the squared portion  86   a  of the shaft member  86 . A cap  88  is fixedly engaged to an aperture  55   c  of the projecting portion  55   y   1 .  
         [0118]    When the portable communications device  50  is folded closed as shown, for example, in FIGS. 2A and 3, the torsion coil spring  83  is twisted and the display cover unit  52  is impelled by the force of the torsion coil spring  83  in an A 1  direction, that is, away and apart from the key pad base unit  51 . Accordingly, when the lock release button  56  is pressed and the lock is released, the force of the torsion coil spring  83  attempting to resume its original shape rotates the display cover unit  52  in the A 1  direction. At this time, the damper unit  86  causes the display cover unit  52  to open slowly, cushioning the shock when the display cover unit  52  reaches the final open position shown in FIG. 2B.  
         [0119]    Additionally, a coaxial-type flexible cable  100  extends through the hinge  53 , and is connected at one end thereof to one connector  78  and at the other end thereof to another connector  78 .  
         [0120]    Accordingly, the printed circuit board  67  inside the display cover unit  52  and the printed circuit board  64  inside the key pad base unit  51  are electrically connected.  
         [0121]    Additionally, at the hinge  53  a coaxial flexible cable  100  is disposed in such a way that, when viewed from the display cover unit  52  toward the key pad base unit  51  from the X 2  side, the coaxial flexible cable  100  forms a counter-clockwise wound loop  101 . The loop  101  in the coaxial flexible cable  100  is accommodated within the adjacently positioned cylindrical portions  80 ,  81  described above. The elasticity of that portion of the coaxial flexible cable  100  that forms the loop  101  rotatably impels the display cover unit  52  to open in the A 1  direction with respect to the key pad base unit  51 . In other words, the loop  101  formed by the coaxial flexible cable  100  at the location of the hinge  53  supplements the torsional spring force of the torsion coil spring  83 .  
         [0122]    Accordingly, a coil spring having a torsional force smaller than usual by an amount equal to the supplementary rotational force supplied by the coaxial flexible cable  100  as described above is used for the torsion coil spring  83 .  
         [0123]    A description will now be given of the coaxial flexible cable  100  described above.  
         [0124]    [0124]FIGS. 12A, 12B and  12 C are diagrams showing top, side and rear views of a coaxial-type flexible cable according to an embodiment of the present invention. FIG. 13 is a diagram showing the structure of the coaxial-type flexible cable shown in FIGS. 12A, 12B and  12 C.  
         [0125]    The coaxial-type flexible cable  100  is of a spacer insertion type, comprising a spacer  103  having an inner conductor pattern  102  at a center thereof, the spacer  103  being sandwiched between and enveloped by a base  104  beneath the spacer  103  and a top cover layer  105  above the spacer  103 . An upper cover  106  lies atop the top cover layer  105  and a lower cover  107  covers the base  104 . Reinforcement plates  108 ,  109  are positioned at either end for added strength.  
         [0126]    The spacer  103  comprises a bottom spacer  115  (with the inner conductor pattern  102  disposed on a top surface of the bottom spacer  115 ) and a top spacer  116  disposed atop the bottom spacer  115 .  
         [0127]    A ribbon pattern  104   a  is provided at a center portion of a bottom surfac of the base  104 . A plurality of signal transmission patterns  104   b  are provided along both sides of a top surface of the base  104 . Each signal transmission pattern  104   b  has terminals  104   c ,  104   d  at either end. Additionally, inner conductor patterns  104   e ,  104   f  are formed along both sides of a center portion of the base  104 . Each of the inner conductor patterns  104   e ,  104   f  has terminals  104   g ,  104   h  at ends thereof.  
         [0128]    The top cover layer  105  has a ribbon pattern  105   a  on a center portion of a top surface thereof. The top cover layer  105  has a width identical to that of the base  104  and covers the spacer  103 , the inner conductor patters  104   e ,  104   f  and the signal transmission pattern  104   b.    
         [0129]    As described above, the spacer  103  is vertically sandwiched between and enveloped by the base  104  and the top cover layer  105 . In such a state, the inner conductor pattern  102  and the inner conductor pattern  104   e  are connected to each other via a through-hole  110 , and the inner conductor pattern  102  and the inner conductor pattern  104   f  are connected to each other via a through-hole  111 . Additionally, as shown in the diagrams, lines of through-holes  112 ,  113  are provided along both sides of the inner conductor pattern  102 . The line of through-holes  112  comprises a plurality of through-holes  112   a  aligned at a pitch “p” that communicate with the top cover layer  105  and the base  104  so as to electrically connect ribbon pattern  105   a  and ribbon pattern  104   a . Similarly, the line of through-holes  113  comprises a plurality of through-holes  113   a  aligned at a pitch “p” that communicate with the top cover layer  105  and the base  104  so as to electrically connect ribbon pattern  105   a  and ribbon pattern  104   a . The pitch “p” is determined by the frequency of the high-frequency signals transmitted via the inner conductor pattern  102 , and is a sufficiently small value so that electromagnetic radiation does not leak from a space between adjacent through-holes  112   a ,  113   a.    
         [0130]    The upper cover layer  106  covers the ribbon pattern  105   a  formed on the top cover layer  105 . The lower cover layer  107  covers the ribbon pattern  104   a  formed on the base  104 .  
         [0131]    As shown in FIG. 12B, one synthetic resin reinforcement plate  108  is fixedly mounted on a bottom surface of one-end of the base  104  so as to strengthen terminals  104   c ,  104   g , with the other synthetic resin reinforcement plate  109  fixedly mounted on the bottom surface of the other end of the base  104  so as to strengthen terminals  104   d ,  104   h.    
         [0132]    The individual patterns described above may be made of copper. The top spacer  116  may be made of polytetrafluoroethylene. The base  104 , the top cover layer  105 , the upper cover layer  106 , the lower cover layer  107  and the bottom spacer  115  may all be made of polyamideimide.  
         [0133]    The inner conductor patterns  102 ,  104   e ,  104   f  together form an inner conductor. The top spacer  116 , the bottom spacer  115  and those portions of the base  104  and the upper cover layer  105  disposed opposite the spacers  116 ,  115  together form an internal insulator. The ribbon patterns  105   a ,  104   a  and through-hole lines  112 ,  113  together form an outer conductor. The upper cover  106  and the lower cover  107  together form an outer insulator.  
         [0134]    As shown in FIG. 6, the coaxial flexible cable  100  described above is connected at both ends to connectors  78 ,  79  and included within the portable communications device  50 , with high-frequency signals transmitted through the inner conductor patterns  102 ,  104   e ,  104   f  from antenna  61 . The flexible cable  100  is of coaxial construction, so electromagnetic radiation is prevented from leaking from the coaxial flexible cable  100 .  
         [0135]    A description will now be given of a portable communications device  50 A according to a second embodiment of the present invention.  
         [0136]    [0136]FIGS. 15A, 15B are diagrams showing a foldaway portable communications device  50 A according to a second embodiment of the present invention, in a closed and an unfolded position, respectively.  
         [0137]    As shown in the diagrams, the chief difference between the portable communications device  50  according to the first embodiment and the portable communications device  50 A according to the second embodiment is that the latter is provided with a projection  150  near a hinge  13 , with the lock release button  20  provided on the projection  150 . The projection  150  is formed in such a way as to project outward from a lateral surface  12   a  of the display cover unit  12 .  
         [0138]    It should be noted that the key pad base unit  11 A has a width in the vicinity of the lock release button  20  that is greater than a corresponding width of the display cover unit  12 .  
         [0139]    [0139]FIG. 15A shows a state in which the portable communications device  50 A is folded closed. The double dot and chain line shows the outline of the left hand  30 , with which the user supports the portable communications device  50 A and which, by using the thumb  31  of the left hand, the user releases the lock and opens the portable communications device  50 A. FIG. 15B shows the portable communications device  50 A in an unfolded position.  
         [0140]    It will be appreciated that the button  20  is provided on the projection  150 , so when the user presses the button  20  with the left thumb  31  that part of the thumb  31  that exceeds the dimensions of the button  20  merely hits the projection  150  instead, without contacting the lateral surface  12   a  of the display cover unit  12 . Accordingly, the display cover unit  12  swings open smoothly, without being hampered by contact with the user&#39;s thumb  31 .  
         [0141]    A description will now be given of a portable communications device  50 B according to a third embodiment of the present invention.  
         [0142]    [0142]FIGS. 16A and 16B are diagrams showing a foldaway portable communications device  50 B according to a third embodiment of the present invention, in a folded position and an unfolded position, respectively.  
         [0143]    As shown in the diagrams, the chief difference between the portable communications device  50  according to the first embodiment and the portable communications device  50 B according to the third embodiment is that the latter is that a portion of a lateral surface  12   a  of the display cover unit  12 B adjacent a lock release button  20  is notched so as to form a concavity  160  thereat.  
         [0144]    [0144]FIG. 16A shows the portable communications device  50 B in a folded position. The double dot and chain line shows the outline of the left hand  30 , with which the user supports the portable communications device  50 B and which, by using the thumb  31  of the left hand, the user releases the lock and opens the portable communications device  50 B. FIG. 16B shows the portable communications device  50 B in an unfolded position.  
         [0145]    It should be noted that the key pad base unit  11  has a width in the vicinity of the lock release button  20  that is greater than a corresponding width of the display cover unit  12 B.  
         [0146]    It will be appreciated that the concavity  160  is formed near the lock release button  20 , so when the user presses the button  20  with the left thumb  31  that part of the thumb  31  that exceeds the dimensions of the button  20  merely enters the interior of the concavity  160  instead, without contacting the display cover unit  12 B. Accordingly, the display cover unit  12 B swings open smoothly, without being hampered by contact with the user&#39;s thumb  31 .  
         [0147]    A description will now be given of a variation of a lock mechanism and lock release mechanism.  
         [0148]    [0148]FIGS. 17A and 17B are diagrams showing a variation of a lock mechanism and lock release mechanism.  
         [0149]    As shown in the drawings, the lock release button  56 A is provided at a tip of an arm  121 , one end of which is supported by a shaft  120 . A pin  121   a  projects from an intermediate portion of the arm  121 . The arm  121  and the lock release button  56 A is contained within an interior space of the guard portion  54 A.  
         [0150]    Additionally, a cylindrical hinge module  130  is contained within a cylindrical portion  65 Aa of the housing  65 A of the display cover unit  52 A. The hinge module  130  comprises a shaft  131 , a disk  132  rotatably supported by the shaft  131  in such a way as to be movable in an axial direction, a lock  133  that locks the disk  132  to the shaft  131 , a torsion coil spring  134  that impels the disk  132  in the A 1  direction with respect to the shaft  131 , and a spring  135  that impels the disk  132  in the X 2  direction. The shaft  131  is fixedly mounted to the key pad base unit  51 A. The disk  132  is accommodated within the interior of the cylindrical portion  65 Aa in such a way as to be integrally rotatable in the A 1 -A 2  direction and movable in the X 1 , X 2  direction.  
         [0151]    When the lock release button  56 A is pressed, the pin  121   a  pushes the disk  132  in the X 1  direction, the lock  133  is released, the torsion coil spring  134  rotates the disk  131  in the A 1  direction and the display cover unit  52 A is rotated in the identical A 1  direction.  
         [0152]    Using the principle of the lever, the force with which the pin  121   a  pushes the disk  132  is increased over the force with which the user presses the lock release button  56 A. Accordingly, a minimal amount of force is sufficient to press the lock release button  56 A and thereby release the lock  133 .  
         [0153]    A description will now be given of a variation of the coaxial-type flexible cable  100  that forms the loop  101  described above.  
         [0154]    [0154]FIGS. 18A, 18B and  18 C are diagrams showing top, side and rear views, respectively, of a first variation of the coaxial-type flexible cable. FIG. 19 is a diagram showing the structure of the coaxial-type flexible cable shown in FIGS. 18A, 18B and  18 C. FIGS. 20A, 20B,  20 C and  20 D are diagrams showing cross-sectional views of the coaxial-type flexible cable shown in FIG. 18A along lines A, B, C and E, respectively.  
         [0155]    The coaxial-type flexible cable  100 A is a standard type, though without the top spacer  116  and the upper cover layer  106  of the coaxial-type flexible cable  100  described above.  
         [0156]    The coaxial-type flexible cable  100 A is constructed so that a spacer  110 A is sandwiched between and enveloped by a base  104 A and a top cover layer  105 A. A lower cover layer  107 A is provided under the base  104 A, with reinforcing plates  108 A,  109 A provided at both sides of the lower cover layer  107 A.  
         [0157]    An inner conductor pattern  102 A comprises an inner conductor. The spacer  110 A and a portion of the base  104 A together form an inner insulator. Ribbon patterns  105 Aa,  104 Aa and through-hole lines  112 A,  113 A together form an outer conductor. Top cover layer  105 A and lower cover layer  107 A together form an outer insulator.  
         [0158]    As a result, the coaxial-type flexible cable  100 A as described above has a simple construction and has the same effect as that of the coaxial-type flexible cable as shown in FIG. 12A.  
         [0159]    A description will now be given of a second variation of the coaxial-type flexible cable.  
         [0160]    [0160]FIGS. 21A and 21B are diagrams showing a side and an expanded cross-sectional view along a line B-B, respectively, of the second variation of the coaxial flexible cable  140 .  
         [0161]    As shown in the diagram, the coaxial flexible cable  140  is constructed so that a narrow coaxial cable  142  having a diameter of approximately 1 mm is laid along a longitudinal center of a top surface of a flexible cable  141 , the coaxial cable  142  being fixedly mounted on the flexible cable  141  using adhesive tape  143 . The coaxial flexible cable  140 , as with the coaxial flexible cable  100  described above, is formed into a loop  101  and inserted in the portable communications device.  
         [0162]    As a result, the coaxial-type flexible cable  140  as described above has a construction that uses an ordinary flexible cable  141 ,and has the same effect as that of the coaxial-type flexible cable  100  shown in FIG. 12A.  
         [0163]    It should be noted that the above-described coaxial cable  142  may alone be formed into the loop  101  and in such a state inserted in the portable communications device.  
         [0164]    Additionally, it should be noted that, although the embodiments described above pertain to a portable communications device, the invention is not limited to such devices but is applicable to any electronic device capable of sending and receiving email, for example, or to an electronic notebook.  
         [0165]    The above description is provided in order to enable any person skilled in the art to make and use the invention and sets forth the best mode contemplated by the inventor of carrying out the invention.  
         [0166]    The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope and spirit of the present invention.  
         [0167]    The present application is based on Japanese Priority Application No. 11-298803, filed on Oct. 20, 1999, the entire contents of which are hereby incorporated by reference.