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BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a hinge device, more particularly a hinge device having angle hold function, and a folding electronic appliance, particularly a folding cellular phone, using same.  
         [0003]     2. Description of the Related Art  
         [0004]     It is a practice to use a hinge devices having angle hold function in order to connect between the main body and the display of a folding electronic appliance, e.g. folding cellular phone.  FIG. 8  shows, in fragmentary exploded perspective view, one example of a folding cellular phone  8  using a conventional hinge device having angle hold function. In this figure, the members are hinge devices  85  referred herein that is to be inserted into left-and-right horizontal holes in directions of arrows shown in the figure in order to connect between a main body  81  and a display  83  of a cellular phone. Those hinge devices  85  are pushed into the left-and-right horizontal holes  87  having rises  88 . By fixing there the hinge devices  85  through utilization of their outer edges, the hinge devices  85  can be fixed in a state allowing to rotate the main body  81  and the display  83 .  
         [0005]     It should be noted that the conventional hinge device  85  has its length  82  comparatively short and its diameter  84  comparatively great. The length  82  provided comparatively short is because to secure a space for a flexible printed circuit board (FPC)  5  (see  FIGS. 3 and 4 , referred later) and coaxial cable (not shown) provided between the main body  81  and the display  83 . Those FPC  5  and coaxial cable are necessarily provided striding between the man body  81  and the display  83  in order to enable signal transfer, etc. between the main body  81  and the display  83 . However, in the conventional cellular phone  8 , the space for passing those structurally exists only in a narrow gap laterally of the hinge device at between the main body  81  and the display  83 . Particularly, the FPC has a considerably large width, e.g. 2 mm, as compared to the ordinary conductor line or the like. Accordingly, the conventional cellular phone is not necessarily secured with a space sufficient for the FPC.  
         [0006]     Meanwhile, the diameter  84  provided comparatively great is due to the hinge device length  82  given comparatively short. As well known, in order to exhibit the angle hold function, an elastic member, e.g. a spring, is necessarily provided within the hinge device  85 . As is apparent, in the case of using a spring having a different length to obtain the equivalent magnitude of elastic force, a spring shorter must have a diameter greater than that of a longer spring. The hinge device having a great diameter results in an increased size of the connection  89  between the main body  81  and the display  83  and hence of the cellular phone  8  itself. Thus, there is a difficulty in making the conventional hinge device compact in size.  
         [0007]     Furthermore, where using the conventional hinge device  85 , the hinge device  85  must be inserted laterally into the horizontal hole  87  of cellular phone  8  which requires the operation lateral thereof on the production line. Such a lateral operation is extremely troublesome as compared to a vertical operation, resulting in the increase in manufacturing and assembling costs.  
         [0008]     Furthermore, the conventional structure requires such a troublesome operation as passing the FPC through a narrow gap laterally of the hinge device. In addition, there is a need to provide a rise  88  for fixing the hinge device in the horizontal hole  87  of the cellular phone  8 . Those factors are also responsible for cost increase.  
         [0009]     Furthermore, because the conventional electronic appliance, e.g. the cellular phone shown in  FIG. 8 , uses a hinge device similar in structure to all the electronic appliances, the design thereof also is similar hence raising the problem of difficulty in providing design difference.  
         [0010]     Furthermore, the cellular phone  8  using the conventional hinge device has an angle the display  83  is opened relative to the main body  81  is limitedly up to the angle of communication, e.g. approximately 154 degrees. In the case such a cellular phone is accidentally trodden under foot, the cellular phone is to be possibly broken.  
         [0000]     (Patent Document 1) JP-A-10-246222  
       SUMMARY OF THE INVENTION  
       [0011]     The present invention has been made in order to solve the problem in the prior art, and it is an object thereof to provide a hinge device more compact in size. Meanwhile, another object is to manufacture a cellular phone compact in size and innovative in design at low cost. Furthermore, it is still another object to provide a cellular phone highly secured.  
         [0012]     In order to achieve the object, a hinge device of the invention comprises: a shaft substantially long; a fixed cam provided allowing the shaft to rotate and having an angle holder; a movable cam provided to rotate about the shaft with rotation of the shaft and to slide along the shaft, and having an angle holder for holding at a predetermined angle an own rotation angle relative to the fixed cam cooperatively with the angle holder of the fixed cam; elastic means always biasing the movable cam toward the fixed cam; a first arm fixed to the fixed cam; and a second arm fixed to the shaft.  
         [0013]     In the hinge device, the elastic means may have a diameter provided comparatively small correspondingly to the shaft substantially long.  
         [0014]     Meanwhile, a hinge device of the invention comprises: a shaft substantially long; a fixed cam supporting the shaft at a position close to one end of the shaft so as to allow rotation of the shaft and having a fixed surface having an angle holder on the other side of the shaft; a movable cam provided to rotate about the shaft with rotation of the shaft and to slide over the shaft along the shaft, and having an angle holder for holding at a predetermined angle an own rotation angle relative to the fixed cam by engagement with the angle holder of the fixed cam, in a rotation surface opposed to the fixed surface of the fixed cam; a spacer provided close to the other end of the shaft; a spring provided for expansion/contraction between the spacer and the movable cam and always biasing the movable cam toward the fixed cam; a first arm fixed to the fixed cam; and a second arm fixed to the shaft; wherein the spring means has a diameter provided as comparatively small correspondingly to the shaft substantially long.  
         [0015]     Meanwhile, in the hinge device, the first arm and the second arm can define an angle varying in a range of at least substantially 0 degree to substantially 180 degrees. Meanwhile, a folding cellular phone may be formed by fixing a display and a main body to the first arm and the second arm of the hinge device. Furthermore, the hinge device may be provided on the cellular phone substantially over an entire width thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is an exterior perspective view of a folding cellular phone using a hinge device of the present invention, showing particularly a non-use state;  
         [0017]      FIG. 2  is an exterior perspective view of a folding cellular phone using a hinge device of the present invention, showing particularly a use state;  
         [0018]      FIG. 3  is a view showing a state that a main body and display is removed from  FIG. 1   
         [0019]      FIG. 4  is a view showing a state that a cover is removed from  FIG. 3   
         [0020]      FIG. 5  is an exterior perspective view of a hinge device of the invention, showing particularly a state that the angle defined by the hinge arms is held at approximately 0 degree;  
         [0021]      FIG. 6  is a fragmentary magnifying perspective view of the hinge device of the invention, showing particularly a state that the angle defined by the hinge arms is held at approximately 154 degrees;  
         [0022]      FIG. 7  is a fragmentary magnifying perspective view of the hinge device of the invention, particularly showing a state the angle defined by the hinge arms is extended up to approximately 180 degrees; and  
         [0023]      FIG. 8  is a fragmentary exploded perspective view of a cellular phone using a hinge device of the prior art. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]     Although the hinge device of the present invention is applicable to various electronic appliances, explanation is herein made particularly on the application to a folding cellular phone as a preferred embodiment.  
         [0000]     1. Outline  
         [0025]      FIGS. 1 and 2  show exterior perspective views of a folding cellular phone of the present invention using a hinge device according to the invention. The folding cellular phone  3  has a main body  11  and a display  13  that are rotatably connected with each other by the utilization of a hinge device  1  of the invention.  FIG. 1  shows particularly a non-use state while  FIG. 2  particularly a use state, i.e. a state of communication or so.  
         [0026]     As shown in the figures, the angle of between main body  11  and display  13  of the cellular phone  3  is approximately 0 degree during non-use in  FIG. 1  while the angle of between main body  11  and display  13  is, say, approximately 154 degrees during the use in  FIG. 2 . As detailed in the below, the cellular phone  3  is to be rotated freely at least between 0 degree and 154 degrees and fixed to an angle of 154 degrees, similarly to the cellular phone using the conventional hinge device. However, the cellular phone  3  using a hinge device  1  of the invention is allowed to rotate up to 180 degrees exceeding 154 degrees, differently from the cellular phone using the conventional hinge device. However, as explained later, in the case of exceeding 154 degrees, spring back is effected to the angle 154 degree. By virtue of such a structure, the folding cellular phone  3  using the hinge device  1  of the invention can cope with an abnormal load. For example, even in the case the cellular phone  3  is trodden under foot from above, the cellular phone is not to be broken unless the main body  11  and the display  13  are opened to an angle of approximately 180 degrees or greater. Nevertheless, such hold angle and rotatable angle can be freely established by the designer without limited to the angle exemplified above, as clear from the following explanations.  
         [0027]     2. Hinge Device and Its Peripheral Members  
         [0028]     There are shown exterior perspective view in  FIG. 3 a  state the main body and display is removed from  FIG. 1 , in  FIG. 4 a  state the cover for hinge device is removed from  FIG. 3 , and further in  FIG. 5 a  state the FPC is removed from  FIG. 4 , respectively. Of these figures,  FIG. 5  just shows the hinge device  1  of the invention.  
         [0029]     As favorably shown in  FIG. 4 , there is provided an FPC  5  having ends to be connected respectively to the main body  11  and the display  13  (see  FIGS. 1 and 2 ), in nearly the center of the hinge device  1  of the invention. The FPC  5  has a comparatively large width of 8 mm for example, and arranged in a state wound twice over there. Winding the FPC  5  is because to improve the resistance to repetitive bending on the FPC. However, the width and number of turns of FPC is, of course, not limited to those exemplified here. In the case of using the hinge device  1  of the invention, the FPC  5  can be provided in a state wound over the hinge device  1 . In other words, it can be provided over the full width of the hinge device  1 . Accordingly, when connecting between the main body and the display, there is no need of such a troublesome operation as passing the FPC through a narrow gap laterally of the hinge device as required in the conventional.  
         [0030]     As favorably shown in  FIG. 3 , a cover  7  covering the hinge device  1  has, say, four portions, i.e. two cylindrical portions  71  having horizontal slits and two lid-like portions  73  arranged at both ends thereof. Particularly, the cylindrical cover portion  71  is cut with a horizontal slit  75  for externally drawing the FPC  5 , lengthwise between both ends (incidentally, although the horizontal slit  75  is shown only on the right, a similar slit may be considered provided also on the left). These cover portions  71 ,  73  cover nearly the entire of the hinge device  1  except for the region of hinge-arm fixing points  24  and their surroundings where the main body  11  and the display  13  (see  FIGS. 1 and 2 ) of the cellular hone are directly connected together.  
         [0031]     Referring to  FIG. 5 , explanation is now made on the structure of the hinge device of the invention. The hinge device  1  of the invention includes a shaft  21  comparatively long (at least longer than that of a hinge device  85  used in the conventional cellular phone  8 ), hinge arms  23 A,  23 B arranged close to one end of the shaft, hinge arms  23 C,  23 D arranged close to the other end of the shaft, annular washers  30  provided respectively between the hinge arms  23 A and  23 B and between the hinge arms  23 C and  23 D, an annular cam (fixed cam)  40  provided on the side close to the hinge arms  23 A,  23 B, a cylindrical cam follower (movable cam)  50  for movement responsive to an action of the cam, a cylindrical spacer  60  arranged close to the other end of the shaft, a spring  62  provided between the spacer  60  and the cam follower  50  and always biasing the cam follower  50  toward the cam  40 , and a C-form stopper (E-ring)  64  for preventing the hinge arm  23 , etc. from falling out of the shaft  21 .  
         [0032]     Although not clear from the figure, the hinge arms  23 A,  23 C of these members are fixed to the shaft  21  directly or indirectly. Accordingly, by rotating the hinge arm  23 A,  23 C, the shaft  21  is rotated. The cam follower  50  is provided to rotate about the shaft and to slide over the shaft  21  and along the shaft  21  as the shaft  21  rotates. Meanwhile, the hinge arms  23 B,  23 D are fixed mutually to the cam  40  directly or indirectly but not fixed to the shaft  21 . Accordingly, the hinge arms  23 B,  23 D and the cam  40  do not rotate even when the shaft  21  rotates. It is not problematic here whether or not the other members, i.e. the spring  62 , the spacer  60  and the stopper  64  are to rotate due to a rotation of the shaft  21 . It can be basically considered that no rotation takes place even when the shaft  21  rotates, similarly to the hinge arms  23 B,  23 D, etc.  
         [0033]     The shaft  21 , penetrating centrally of the hinge device  1 , is provided over nearly the entire width thereof. The shaft  21  has a length  22  capable of determining a width of the hinge device  1  and, ultimately, a width of a cellular phone  3  using the hinge device  1  of the invention. More specifically, the hinge device  1  of the invention can be provided between the display  13  and the main body  11 , i.e. over the entire width of the cellular phone, to make the width of cellular phone  3  nearly equal to the width of the hinge device  1 . This is because, where the hinge device  1  of the invention is used, as explained referring to  FIGS. 3 , and  4 , there is no need of providing a gap lateral of the hinge device in order to attach an FPC  5 , the spring  62  (and the spacer  60 ) can be set freely in length. Also, the hinge device  85  (see  FIG. 8 ) is not required two in the number as needed on the conventional cellular phone. As clear from the below explanation, the length  22  of the shaft  21  used in the invention, more specifically the width of the cellular phone  3  of the invention using the hinge device  1  of the invention, is greater than the length  82  of one conventional hinge device  85 , shown in  FIG. 8 . However, it can be easily set smaller than the width (length thereof) of the cellular phone  3  using the conventional hinge device  1  (or can be set greater, of course).  
         [0034]     The hinge arms  23 A- 23 D are to be fixed to the subject of hinge connection, e.g. the display  11  and main body  13  (see  FIGS. 1 and 2 ) of cellular phone  3 . The hinge arms  23 A- 23 D have fixing portions  24 A- 24 D to be fixed to the main body and display, and annular portions  25 A- 25 D to be inserted over the shaft  21 . The fixing portions  24 A- 24 D and the annular portions  25 A- 25 D are connected together in a state twisted 90 degrees through bend portions  26 A- 26 D ( 26 B being not shown) The fixing portion  24 A,  24 C of the hinge arm  23 A,  23 C is fixed to the display  13  (see  FIGS. 1 and 2 ) of the cellular phone  3  by inserting a screw (not shown) in the center thereof. Meanwhile, the fixing portion  24 B,  24 D of the hinge arm  23 B,  23 D is fixed to the main body  11  (see  FIGS. 1 and 2 ) of the same by the similar way. Meanwhile, the annular portion  25 A,  25 C of the hinge arm  23 A,  23 C is fixed to one end of the shaft  21  in a state the shaft  21  penetrates through a hole thereof (not shown). The annular portion  25 C,  25 D of the hinge arm  23 C,  23 D is provided in a state the shaft  21  is inserted through a hole thereof (not shown) and in a state the shaft  21  within the hole is allowed to rotate freely. Incidentally, the fixing portion  24 A- 24 D is determined in its form by taking into consideration merely screwing to the cellular phone  3 , which form is to be determined depending upon the subject of hinge connection thus being limited to the form shown.  
         [0035]     The cam  40  is arranged close to one end of the shaft  21 , in a state the shaft  21  penetrates through a hole (not shown) provided in the center thereof and in a state the shaft  21  is allowed to freely rotate at the inside of the hole. The cam  40  allows the shaft  21  to rotate at the inside thereof during rotation of the shaft  21  but does not move itself due to rotation of the shaft. The cam  40  has two slant surface, i.e. a first slant surface  44  and a second slant surface  45 , such that the cam  40  decreases its thickness from the center the shaft  21  penetrates toward the circular edge  43 , bordering a predetermined diameter partitioning into halves the fixed surface  41  on the other end of the shaft  21 , in other words, the diameter  42  assumes a crest. Incidentally, although the second slant surface  45  is not favorably represented in the figure, the slant surfaces  44 ,  45  are provided with a groove  46  in a predetermined depth extending from the center to the edge  43  of the cam  40 . The groove  46  is to be used to hold the angle of cam follower by engagement with the protrusions  51 ,  53  of the cam follower, as described later. The slant surfaces  44 ,  45  have two fan-formed slant surfaces, i.e. a first fan surface  47  and a second fan surface  48 , respectively formed at slant angles somewhat different bordering the groove  46 . Here, the first fan surface  47  has an internal angle A of approximately 56 degrees while the second fan surface  48  has an internal angle B of approximately 124 degrees. Because the first fan surface  47  and the second fan surface  48  are both slanted to have the deepest valley at the groove  46 , there are somewhat difference between the slant angle C of the first fan surface  47  (i.e. cam  40  thick-wise slant) and the slant angle Dof the second fan surface  48  in relation to the internal angles A, B. Namely, the slant angle C of the first fan surface  47  is provided greater than the slant angle D of the first fan surface  48 .  
         [0036]     The cam follower  50  is provided, in a state the shaft  21  penetrates through a hole (not shown) provided in its center, to rotate about the shaft  21  as the shaft  21  rotates and further to slide over the shaft  21  along the shaft  21 . The cam follower  50  has protrusions two in total, i.e. a first protrusion  51  and a second protrusion  53  in the rotation surface opposed to the fixed surface  41  of cam  40 , correspondingly to the groove  46  of cam  40  (see  FIGS. 6 and 7 ). The first protrusion  51  and the second protrusion  53  are provided symmetric as viewed at the center of the cam follower  50 . By an engagement of the first and second protrusions  51 ,  53  in the groove  46  of cam  40 , the rotation angle of the cam follower  50  relative to the fixed cam (the resulting angle of between hinge arms  23 A,  23 C and hinge arms  23 B,  23 D that are respectively fixed to those) can be held at a predetermined, e.g. 154 degree. Incidentally, the cam follower  50  has the other end  56  always in a contact state with the spring  62 , described in the following.  
         [0037]     The spring  62  is provided for expansion/contraction between the cam follower  50  and the spacer  60 , in a state the shaft  21  penetrate through the interior thereof and in a state the shaft  21  is allowed to rotate at the inside thereof. The spring  62  always biases the cam follower  50  toward the cam  40 . Particularly, when the protrusion of cam follower  50  fits in the groove  46  of cam  40 , the same plays an important role in order to hold that state. The spring  62  must have a sufficient elastic force to effect this role. In order to provide a sufficient elasticity, a sufficient length  65  must be provided in relation to the size of the diameter  63 . As noted above, according to the hinge device  1  of the invention, because the length  65  of the spring  62  can be freely set, the spring  62  can be easily made longer in its length  65  than that of the spring  62  of the conventional hinge device  1 . By thus setting the spring  62  length  65  longer than that of spring ( 82 ) of the conventional hinge device  8 , the diameter  63  of spring  62  (and further the hinge device  1  diameter using the spring  62 ) can be made smaller than that ( 84 ) of the conventional. As a result, the invention can make more compact the hinge device  1  and the cellular phone  3  using the same.  
         [0038]     The spacer  60  is arranged between the spring  62  and the hinge arms  23 C,  23 D in a state the shaft  21  penetrate through the interior thereof and preferably in a state the shaft  21  is allowed to freely rotate at the inside thereof. Properly adjusting the length of the spacer  60  makes it possible to adjust the biasing force of the spring  62  to the cam  40 . Incidentally, in order for the spacer  60  not to apply an unnecessary force to the hinge arm  23 C, a pin (not shown) may be provided in a manner partitioning between the spring  62  and the hinge arm  23 C. The pin, for example, radially extends from the shaft  21  orthogonally to the shaft  21 , having a length nearly equal to or smaller than the radius of the spacer  60 . Incidentally, as clear from the above explanation, the length of the spacer  60  is determined relatively in relation to the biasing force, etc. of the spring  62 .  
         [0039]     Stoppers  64  are provided outermost at both ends of the shaft  21  thus preventing hinge arms  23 , etc. from falling out of the shaft  21 . The stoppers  64  are arranged adjacent the annular portions  25 A,  25 D of the hinge arms  23 A,  23 D, to fix the shaft  21  firmly at the C-formed inside thereof in a manner clamping same there. Incidentally, although the stoppers  64  may be provided as separate members from other members as in the illustrated example, those may be formed by rolling the ends of the shaft  21 .  
         [0000]     3. Hinge Device Operation  
         [0040]     Referring subsequently to  FIG. 5  and further to  FIGS. 6 and 7 , the operation of the hinge device is explained.  
         [0041]     When viewed in respect of operation,  FIG. 5  shows a state the hinge arms  23 A,  23 C and the hinge arms  23 B,  23 D define an angle held at approximately 0 degree, which can be considered showing a non-use state shown in  FIG. 1  if considering the cellular phone  3  example shown in  FIGS. 1 and 2 . Meanwhile,  FIG. 6  shows a state the angle of between those is held at approximately 154 degrees, which can be considered showing a use state (state of communication or so) shown in  FIG. 2  if considering the cellular phone  3  example.  FIG. 7  shows a state the angle of between those is extended to approximately 180 degrees, which can be considered showing a state of abnormality if considering the cellular phone  3  example. Note that, in  FIGS. 6 and 7 , the cam  40  and its periphery only is shown as a fragmentary magnifying perspective view.  
         [0042]     As shown in  FIG. 5 , when the hinge arms  23 A,  23 C and  23 B,  23 D define an angle of approximately 0 degree, those hinge arms are allowed to move only in the direction the angle thereof increases, in other words, only in the direction the first protrusion  51  (and second protrusion  53 ) goes up the slanting, first fan-formed surface  47 . Accordingly, this state is maintained unless a certain force is applied to the hinge arms  23 A,  23 C.  
         [0043]     In the  FIG. 5  state, when to rotate the hinge arms  23 A,  23 C in the direction of arrow shown in the figure or to open the display if considered on the cellular phone  3  example, the cam follower  50  fixed on the hinge arms  23 A,  23 C is rotated together with the hinge arms  23 A,  23 C while being pushed toward the spacer  60  against the force of spring  62 . At this time, the first protrusion  51  (and second protrusion  53 ) is to move the first fan-formed surface  47  in a direction of going up the slant surface thereof. Accordingly, in case the force to move the hinge arms  23 A,  23 C is loosened in the course thereof, the cam follower  50  rotates reverse in direction to the arrow shown in the figure thus possibly making a spring-back to the former position.  
         [0044]     When the hinge arms  23 A,  23 C are rotated nearly 30 degrees in the direction of arrow shown in the figure without loosening the force for rotation, the first protrusion  51  (and second protrusion  53 ) of cam follower  50  gets over the crest of the diameter  42  of cam  40  and then moves the second fan-formed surface  48  in a direction going down the slant surface thereof. Accordingly, unless a force is applied reverse in direction to the arrow shown in the figure, the can follower  50  does not return to the former position again. The action getting over the crest corresponds to opening/closing operation of the display and main body if considered on the cellular phone example.  
         [0045]     As favorably shown in  FIG. 6 , when the angle of rotation reaches approximately 154 degrees, the second protrusion  53  (first protrusion  51 ) reaches the groove  46  of the first slant surface  44  (second slant surface  45 ). As a result, the cam follower  50  snaps into fitting in the groove  46  of cam  40  by the action of spring  62 . Because the cam follower  50  is always biased toward the cam  40  by means of the spring  62 , this state or the angle of 154 degrees is maintained unless any of force is applied to the hinge arms  23 A,  23 C.  
         [0046]     In abnormality, when the hinge arms  23 A,  23 C are rotated exceeding 154 degrees in the arrow direction shown in the figure relative to the hinge arms  23 B,  23 D, or when the display is opened exceeding the state of communication relative to the main body if considered on the example of cellular phone  3 , as shown in  FIG. 7  the cam follower  50  is rotated together with the hinge arms  23 A,  23 C exceeding 154 degrees while being pushed toward the spacer  60  against the force of spring  62 . At this time, the second protrusion  53  (first protrusion  51 ) of cam follower  50  goes out of the groove  46  of cam  40  and moves up the first fan-formed surface  47 . Accordingly, the cam follower  50  undergoes a force in the direction opposite to the direction of arrow shown in the figure. As a result, the hinge arms A, C are allowed to make a spring-back to the former angle, or 154 degrees.  
         [0000]     4. Assembling  
         [0047]     Referring to FIGS.  1  to  5 , brief explanation is finally made on a method of assembling the hinge device  1  of the invention into a cellular phone  3 . Before assembling to the cellular phone  3 , the hinge device  1  is made in the state of  FIG. 3 . This is to be done by winding an FPC  5  over the shaft of hinge device  1  as shown in  FIG. 4  (not assembled with hinge arms  23 C,  23 D and a stopper, in this stage), attaching cylindrical covers  71  to the FPC  5  wound shaft from both sides in a manner wrapping those together with the FPC from the external, assembling hinge arms  23 C,  23 D and fixing the respective ends by a stopper  64 , and finally attaching lid cover portions  73  on the both sides of the cylindrical cover portions  71 . As a result, a hinge device is obtained in the state of  FIG. 3 . Then, the fixing portions  24 A- 24 D of hinge arms  23 A- 23 D exposed from the cover  7  are screwed, from above, with the main body  11  and display  13  of the cellular phone  3 . Furthermore, the ends of FPC  5  exposed from the cover are respectively connected to predetermined positions of the main body  11  and display  13 . Finally, the lids, etc. of main body  11  and display  13  are closed into a completion.  
         [0048]     In this manner, in the cellular phone  3  using the hinge device  1  of the invention, there is no need of complicated operations including passing an FPC through a narrow gap laterally of a hinge device and assembling a hinge device  85  laterally as required in a cellular phone  8  (see  FIG. 8 ) using a conventional hinge device  85 . Furthermore, there is also no need of providing a cellular phone  8  with a hole  87  (see  FIG. 8 ) horizontally and a rise  88  there as needed in the case using a conventional hinge device. Accordingly, in the case of using the hinge device of the invention, it is possible to fabricate a cellular phone cheaper in price than those of the conventional. Meanwhile, because the hinge device of the invention is apparently different in shape from the conventional hinge device, it is possible to easily produce a design different from that of the conventional cellular phone or electronic appliance by use of the hinge device of the invention.  
         [0049]     Incidentally, the embodiment fixed the cam to provide the cam follower rotatable, the cam follower may be fixed to provide the cam rotatable conversely. Meanwhile, although the embodiment provided the hinge-arm extension angle at approximately 180 degrees, it can be provided greater than that. This angle can be determined freely in relation to the subject of hinge device connection (and its structure), etc.  
         [0050]     The invention allows for fabricating a compact hinge device at low cost. Meanwhile, The invention can provide an innovatively designed electronic appliance and a highly secure cellular phone.

Summary:
This aims at providing a hinge device compact in size, and at securing a space sufficient for an FPC, etc. in manufacturing a cellular phone compact by use of the hinge device. The hinge device includes a shaft substantially long, a fixed cam provided allowing the shaft to rotate and having an angle holder, a movable cam provided to rotate about the shaft with rotation of the shaft and to slide along the shaft, and having an angle holder for holding at a predetermined angle an own rotation angle relative to the fixed cam cooperatively with the angle holder of the fixed cam, an elastic element always biasing the movable cam toward the fixed cam, a first arm fixed to the fixed cam, and a second arm fixed to the shaft. Here, the elastic element is to have a diameter provided as comparatively small correspondingly to the shaft substantially long.