Abstract:
It is an object of the present invention to ensure an intermediate position and an opening-closing operation with a good modulation in a sliding hinge by adding a third fixing position substantially in the middle of the slidability region of the sliding hinge, wherein the withdrawal from the third fixing position is performed by a combined force of the repulsive force of the north magnetic pole and south magnetic pole and the assist force of the elastic body. 
     A sliding hinge mechanism, wherein the sliding hinge has at least an elastic body and magnets, the first housing and the second housing can move relative to each other, and a slidability region, which extends from a first fixing position in which the first housing and the second housing are completely closed to a second fixing position in which the second housing is completely open, additionally includes a third fixing position being an intermediate position of the slidability region in which the second housing is temporarily fixed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a hinge mechanism for use in an electronic device such as a cellular phone that typically has a main body section provided with an operation section such as a keyboard and a liquid crystal display segment that displays images, the hinge mechanism being suitable for use in a sliding device in which the main body section and the liquid crystal display segment are coupled slidably relative to each other. 
         [0003]    2. Description of the Related Art 
         [0004]    A typical sliding hinge mechanism incorporated in a sliding electronic device, for example a cellular phone, is a component that enables a series of operations from a first fixing position in which a liquid crystal display segment  4  is closed, as shown in  FIG. 5(   a ), to a second fixing position ( FIG. 5(   b )) in which the liquid crystal display segment is open by holding a main body portion in one hand and sliding, through about 30 mm to 50 mm, the liquid crystal display segment by using, in particular, the thumb of the same hand, in case of typing in the numbers to call, operating the keyboard to send text messages, or operating the built-in camera. 
         [0005]    As shown in  FIGS. 5(   a ) and ( b ), in the operation of the conventional sliding hinge mechanism, when a second housing  2  provided with the liquid crystal display segment is pushed to the open state from the first fixing position ( FIG. 5(   a )) corresponding to the closed state with respect to a first housing  3  provided with the keyboard in the sliding cellular phone  1 , at a substantially intermediate position of the slidability region, a force that tries to close the second housing  2  acts upon the second housing due to a pull-in torque created by the repulsive force of a spring, and where pushing is further continued from the intermediate position, an opening force automatically acts upon the second housing  2  and the completely open second fixing position such as shown in  FIG. 5(   b ) is reached. 
         [0006]    Conversely, when the second housing  2  provided with the liquid crystal display segment is returned by a finger or hand in the direction of closing from the second fixing position, the sequence of opening operations is reversed. The torque generated in this case acts in the direction of opening the second housing  2  before the intermediate position and then acts in the direction of automatic closing after the intermediate position. 
         [0007]    In the conventional sliding hinges, the operation torque uses a repulsive force (load) generated by a torsion spring or compression spring as an assist force. In other words, the spring arrangement is generally such that one side of the spring is locked to the first housing  3 , whereas the other side of the spring is located rotatably to the second housing  2 . Further, in order to obtain a sufficient and necessary assist force, it is necessary to design as appropriate the shape, number, and load of springs used in the sliding hinge. 
         [0008]    For example, US Patent No. 2005/0113154 and PCT Application No. 2008-501288 disclose the conventional sliding hinge mechanisms. Further, a sliding hinge is also known that is used in a transversely elongated portable device called a PDA or smartphone, and such a sliding hinge mechanism is disclosed, for example, in Japanese Patent Publication No. 2008-113067. The aforementioned Japanese Patent Publication No. 2008-113067 also discloses a technique of using magnets in combination with a torsion spring with the object of strengthening the joining of the first housing  3  provided with the keyboard with the second housing  2  only in the closed state or completely open position of the sliding hinge. 
         [0009]    The abovementioned patent documents disclose configurations in which a telephone conversation, a keyboard operation such as mailing, and a camera operation are performed only at a position in which the second housing  2  provided with the liquid crystal display segment is in either of the completely closed state and completely open state, and fail to disclose the configuration in which the telephone conversation and the like can be performed when the second housing  2  provided with the liquid crystal display segment is fixed at the intermediate position of the slidability region. 
         [0010]    Further, a technique for obtaining an attraction or repulsive force with a configuration including only magnets instead of a spring is also known. Such a technique is disclosed for example in WO 2004/112267, Korean Patent Publication No. 10-2004-0105657, and Japanese Patent Publication No. 2008-170000. 
         [0011]    In the configuration disclosed in WO 2004/112267, only magnets are used without using springs and a maximum of three sets of rod-shaped magnets having north and south magnetic poles are fixed along both opposite sides in the vertical direction of the first housing  3  and the second housing  2  provided with the liquid crystal display segment in a vertical cellular phone. Three-state positional setting of the closed-state position, intermediate position and open-state position of the second housing  2  can be realized by successively moving one set of magnets fixed to the first housing  3 , while causing the attraction force, between the three sets of magnet portions fixed to the second housing  2 . In this example, the rod-like magnets in which the north and south magnetic poles are alternately magnetized are disposed along the entire sliding length. In this system, strong elongated magnets are disposed and therefore a shield preventing a leak magnetic flux is indispensible to prevent the device malfunction and effect on people. 
         [0012]    In the configuration disclosed in Korean Patent Publication No. 10-2004-0105657, sheet-like large magnets are fixedly attached opposite each other in the central portions of the upper and lower housings of a sliding drive device, the opposing magnets are magnetized to be repulsed from each other, and an assist force that moves the upper and lower housings of the sliding drive device to both ends is obtained by the repulsion of the magnets. However, the patent document does not disclose a mechanism for stopping the upper and lower housings having the magnets disposed in the central portion thereof in the intermediate position during sliding by the attraction caused by magnetic forces. 
         [0013]    In the structure described in Japanese Patent Publication No. 2008-170000, magnetic poles are disposed facing each other and a sliding portion is moved to both ends by magnetic lift created by a repulsive force acting between the magnets. No means for stopping the sliding portion at the intermediate position is used in this structure. 
       SUMMARY OF THE INVENTION 
       [0014]    It is an object of the present invention to use an elastic body together with magnets, add a third fixing position substantially in the middle of the slidability region of the opening-closing sliding hinge, and provide a fixing position for operating an electronic device. 
         [0015]    It is another object to ensure the operation of the sliding hinge in which the third fixing position is newly set by a magnet system, such that closing and opening operations are performed basically by an assist force provided by a repulsive force of the elastic body, the third fixing position is held by attraction of north and south magnetic poles, the withdrawal from the third fixing position is performed by a combined force of the repulsive force of the north magnetic pole and south magnetic pole and the assist force of the elastic body, thereby ensuring the intermediate position and the opening-closing operation with better modulation than in the mechanism using only the spring. 
         [0016]    Considering the spring load characteristic, the torsion spring in the conventional sliding hinge generates the highest load at a substantially intermediate position of the slidability region of any of the operation point. The inventors have recognized that this position is a transition point in which the direction of load is reversed and have set the third fixing position to this transition point. 
         [0017]    The hinge mechanism in accordance with the present invention allows the repulsive force of the spring to generate a force in the direction of automatically closing the housing portion before the intermediate position in the sliding region and a force in the direction of automatically and completely opening the housing portion after the intermediate position. The hinge mechanism also possesses a transition point in which the repulsive load of the spring is maximum, the orientation of the operation torque is changed, and a free stop operation is performed at a substantially intermediate position. 
         [0018]    As shown in  FIG. 5 , in the sliding cellular phone, the assist force generated by the torque is zero in the abovementioned transition point, and the movement of the second housing is stopped (free stop) or slowed down. Where an actual cellular phone is used, the force applied by the user&#39;s finger during sliding operation is such that the lifting force in the series of operations is strong before the intermediate position and the feeling of light flick is obtained after the intermediate position. 
         [0019]    Accordingly, the inventors have succeeded in greatly improving the applicability of portable devices by taking the abovementioned transition point as the third fixing position and setting a fixing means in the third fixing position. 
         [0020]    More specifically, the present invention resolves the above-described problem by using the below-described configuration. 
         [0021]    (1) A sliding hinge mechanism in which a first housing provided with an operation section and a second housing provided with a liquid crystal display segment that displays images are coupled by a sliding hinge, wherein the sliding hinge has at least an elastic body and magnets, the first housing and the second housing can move relative to each other, and a slidability region, which extends from a first fixing position in which the first housing and the second housing are completely closed to a second fixing position in which the second housing is completely open, additionally includes a third fixing position being an intermediate position of the slidability region in which the second housing is temporarily fixed. 
         [0022]    The elastic body used in the present invention may be of any kind, provided that the elastic body can configure a sliding actuator. For example, a torsion spring having a central hoop, a torsion spring without the central hoop, or a compression or tension coil can be used. 
         [0023]    (2) A sliding hinge mechanism in which a first housing provided with an operation section and a second housing provided with a liquid crystal display segment that displays images are coupled by a sliding hinge, wherein the sliding hinge has at least an elastic body and magnets, the first housing and the second housing can move relative to each other, the first housing and the second housing can slide from a first fixing position to a second fixing position, the slidability region additionally includes at an intermediate position thereof a third fixing at which the second housing is temporarily fixed, and the third fixing position is a position in which the first housing and the second housing are completely closed. 
         [0024]    (3) The sliding hinge mechanism described in clause (1) or (2) above, wherein a torsion spring is used as the elastic body, the first housing of the sliding hinge has a first housing sliding member, the second housing has a second housing sliding member, the ends of the torsion spring are rotatably locked to the first housing sliding member and the second housing sliding member, respectively, the third fixing position is set to a position at which a repulsive force created by the torsion spring is maximum in the slidability region, and magnets, in which the north and south magnetic poles thereof are arranged facing each other so that attraction forces mutually act upon the first housing sliding member and the second housing sliding member, are disposed at the third fixing position. 
         [0025]    (4) The sliding hinge mechanism described in any one of clauses (1) to (3) above, wherein the magnets are in the form of rectangular parallelepipeds, have a coercive force (Hcj) of equal to or higher than 800 KA/m (10 kOe), and have north and south magnetic poles magnetized on upper and lower surfaces in the sheet thickness direction. 
         [0026]    The sheet thickness of the magnets in the form of rectangular parallelepipeds is preferably equal to or less than 1 mm. 
         [0027]    (5) The sliding hinge mechanism described in any one of clauses (1) to (4) above, wherein the magnets are configured such that magnets in the form of rectangular parallelepipeds are disposed facing each other perpendicularly to the movement direction of the first housing and the second housing so as to have a north magnetic pole and a south magnetic pole and exert an attraction force. 
         [0028]    (6) The sliding hinge mechanism described in any one of clauses (1) to (4) above, wherein the magnets are configured such that two magnets in the form of rectangular parallelepipeds are disposed parallel to each other and perpendicularly to the movement direction of the first housing and the second housing, disposed so that the surfaces of the magnets exert a north magnetic pole and a south magnetic pole, and disposed so that the north magnetic pole and the south magnetic pole face each other in the magnets disposed at the first housing and the second housing, thereby exerting an attraction force. 
         [0029]    The effect demonstrated by the present invention is that the movement of the second housing provided with a liquid crystal display segment of a sliding cellular phone can be newly fixed at an intermediate position of the slidability region. Further, the telephone communication, keyboard operation, and camera operation are possible at a position corresponding to the closed state, intermediate state, and open state of the second housing, and the possibilities of new usage modes are provided in terms of arrangement and setting of buttons and switches. 
         [0030]    Further, setting the intermediate third fixing position at a position in which the first housing  3  and the second housing  2  are closed enables an operation of opening the housing section upward and downward and also makes it possible to develop models of new usage modes. 
         [0031]    The effect of the present invention that enables the use of the intermediate position in the slidability region is achieved by combined use of an elastic body and magnets, and allows new motions and design variations. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    The sliding hinge mechanism in accordance with the present invention has a configuration such that upper and lower first and second housings can be reliably stopped at a third fixing position which is located in the slidability region, by a combination of a spring and magnets. 
         [0033]    In order to stop the first housing and the second housing reliably at the third fixing position, it is particularly preferred that strong magnets having a thin and elongated shape extending in the direction perpendicular to the sliding direction be disposed in the vicinity of the third fixing position. With such a configuration, it is possible to realize an attracting movement with nicely modulated click feel. 
         [0034]    Further, it is possible to use magnets facing each other and having the surfaces thereof magnetized to a north magnetic pole and a south magnetic pole and hold the upper and lower housings of the sliding hinge by the attraction force acting between the magnets. In this case, the second housing can be moved from the third fixing position to the first or second fixing position by pushing the second housing up or down with a finger. 
         [0035]    Further, it is preferred that the magnets used in the sliding hinge mechanism in accordance with the present invention have a coercive force (Hcj) of equal to or higher than 800 kA/m (10 kOe). For example, rare earth magnets that are difficult to demagnetize are preferably used. 
         [0036]    In order to ensure modulated movement, it is preferred that the magnets be in the form of rectangular parallelepipeds, have a small thickness and a shape of narrow rods and that the north magnetic pole and south magnetic pole be magnetized on the upper and lower surface in the thickness direction. 
         [0037]    Small magnets disposed perpendicular to the sliding direction are useful from the standpoint of cost and magnetic shielding technique that prevents the leak magnetic flux. 
         [0038]    The relationship between the movement distance (mm) and assist force (N) in the sliding hinge mechanism in accordance with the present invention will be explained below.  FIG. 4  shows a graph in which the assist force is plotted against the ordinate and the movement distance is plotted against the abscissa. In the figure, the slidability range is 40 mm, a transition point of the spring is at the intermediate of 20 mm (origin point), and the assist force (N) is represented by a positive load (N) before the intermediate point and a negative load at the transition point and thereafter. 
         [0039]    In the assist force characteristic of the conventional sliding hinge mechanism, the first fixing position in which the housing portion is completely closed by the closing force E is at a position of −20 mm in the figure, and the second fixing position in which the housing portion is completely open by the opening force F is at a position of +20 mm. The sliding hinge can slide between the E— 0  (origin point)—F. The assist force is positive between −20 mm and 0, and therefore the sliding hinge acts in the direction of closing the second housing provided with the liquid crystal display segment. Conversely, the assist force is negative between 0 and 20 mm and therefore the force automatically acts in the direction of completely opening the second housing. 
         [0040]    The dotted portions (A, D) and hatched portions (B, C) close to the origin point of the characteristic curve show the effect of magnets used in the sliding hinge mechanism in accordance with the present invention in comparison with that obtained in the conventional configuration. The dotted portions (A, D) show repulsive forces from the same magnetic polarity generated between the magnet of the first housing sliding member and the magnet of the second housing sliding member. The hatched portions (B, C) close to the origin point show attraction forces from opposite magnetic polarity generated between the two magnets. 
         [0041]    The mechanism for fixing the movement of the first housing sliding member with respect to the second housing sliding member at the intermediate third fixing position will be described below. By contrast with the conventional sliding hinge, between the two magnets as the origin point  0  in  FIG. 4  is approached, a large attraction force (B) or (C) with a reversed force direction is generated following the repulsive force (A) or (D). 
         [0042]    Therefore, the first housing sliding member initially receives a return force in a direction opposite to the movement due to the action of the repulsive force (A) or (D), but where the first housing sliding member is further pushed up by a hand to the origin point  0 , the first housing sliding member is forcibly moved and fixed at the origin point  0  with modulation by the attraction force (B) or (C). 
         [0043]    Where an attempt is made to move the first housing sliding member further from the origin point  0  (third fixing position), the attraction force (B, C) tries to return the first housing sliding member to the origin point  0 . The modulated movement occurring in the vicinity of the origin point  0  according to the present application can be provided with an abrupt change of the assist force that is different from that of the conventional configuration by disposing a pair of magnets in the form of narrower rectangular parallelepipeds close to each other in the direction perpendicular to the sliding direction. 
         [0044]    The movement of the housing in the sliding hinge mechanism in accordance with the present invention will be explained below with reference to  FIG. 5 .  FIGS. 5(   a ) and  5 ( b ) illustrate the conventional sliding hinge mechanism, and  FIGS. 5(   c ),  5 ( d ), and  5 ( e ) illustrate a sliding cellular phone  1  incorporating the sliding hinge mechanism in accordance with the present invention. The sliding cellular phone  1  has a second housing  2  provided with a liquid crystal display segment, a first housing  3  provided with a keyboard, a liquid crystal screen  4 , a keyboard  5 , functional key portions  6 ,  7 ,  8 , and  9 , and an external connection terminal  10 . In the conventional cellular phone  1 , the opening-closing movement relative to the first housing  3  can be performed only between the first fixing position in which the second housing  2  is closed (this fixing position is shown in  FIG. 5(   a )) and the second fixing position in which the second housing  2  is completely open (this fixing position is shown in  FIG. 5(   b )). 
         [0045]      FIGS. 5(   c ),  5 ( d ), and  5 ( e ) are schematic drawings illustrating the movement of the cellular phone incorporating the sliding hinge mechanism in accordance with the present invention. 
         [0046]    The hinge in accordance with the present invention in which the third fixing position is newly provided in the intermediate position by the attraction force of magnets provides a sliding cellular phone in which two below described types of movement can be performed. 
         [0047]    Firstly, as compared to the movement realized in the conventional device, in the present invention the third fixing position is added in the intermediate zone, and three fixing positions are configured in which key operations can be performed between (a)← →third fixing position (d)← →(b) shown in the figure. 
         [0048]    Secondly, by setting the intermediate third fixing position as a completely closed position, the (d)← →(c) intermediate position← →(e) movement is realized, and the operation of moving the second housing  2  provided with the liquid crystal up and down with respect to the center as a starting point can be performed, and such an operation cannot be realized in the conventional device. 
         [0049]    In the explanation above, the vertically slidable cellular phone is considered, but a transverse sliding system can be also used. In addition, the sliding hinge mechanism can be applied not only to cellular phones, but also to electronic devices such as PDA. 
         [0050]    Example embodiments of the present invention will be described below with reference to the appended drawings. The embodiments described hereinbelow are merely examples of the present invention, and the present invention is not limited to the below-described embodiments. 
       Embodiment 1 
       [0051]      FIG. 1  is an exploded view illustrating an example embodiment of the sliding hinge mechanism in accordance with the present invention. 
         [0052]    In the sliding hinge mechanism according to Embodiment 1, a first housing sliding member  12  (not shown in the figure) and a second housing sliding member  11  are coupled by a torsion spring  14 . 
         [0053]    Here, the first housing sliding member  12  is obtained by pressing a thin sheet of stainless steel or molding a resin and provided with a hole  21  for inserting and fixing a fixing pin  15  of the torsion spring  14 , a hole  22  for attaching a magnet  16 , a hole  23  for fixing, with a screw or the like, to a first housing  3  provided with a keyboards, and circular-arc portions  26  for fixedly attaching lubricating resin guides  13 . 
         [0054]    The second housing sliding member  11  is obtained by pressing a thin sheet of stainless steel and provided with a hole  18  for fixing, with a screw or the like, to a second housing  2  provided with a liquid crystal display segment, stopper pins  19  that determine the upper and lower limits of a sliding region, a hole  20  for inserting and fixing the fixing pin  15  of the torsion spring  14 , a hole  24  for attaching a magnet  17 , and sliding surfaces  28  on both sides. The sliding members  11  and  12  are preferably made from a nonmagnetic material. 
         [0055]    The permanent magnets  16  and  17  have magnetized north and south magnetic poles on the upper and lower surfaces of a thin sheet. The torsion spring  14  is provided with round hooks  25  at both ends, and the hook  25  has an inner diameter enabling rotation when the torsion spring is externally fitted on and fixed to the fixing pin  15 . 
         [0056]    The lubricating resin guides  13  are formed in a concave shape suitable for fitting therein the sliding surfaces  28  located on both sides of the second housing sliding member  11 . The magnets may be also fixedly attached to the first and second sliding members  11 ,  12  with an adhesive or a pressure-sensitive adhesive tape, and in this case the holed  22  and  24  are omitted. 
       Embodiment 2 
       [0057]      FIG. 2  is a plan schematic drawing illustrating the configuration and movement of the sliding hinge mechanism according to Embodiment 2 in which a third fixing position is newly disposed at an intermediate position of the slidability region by using magnets. Members having functions identical to those of Embodiment 1 are denoted by like reference numerals. 
         [0058]    As shown in  FIG. 1 , the lubricating resin guides  13  and magnets  16 ,  17  are set at the first housing sliding member  12  and the second housing sliding member  11 . 
         [0059]    The sliding surfaces  28  of the second housing sliding member  11  are internally fitted into grooves  27  of the lubricating resin guides  13  that have been set at both sides of the first housing sliding member  12 . The stoppers  19  that restrict the slidability region and both end hooks  25  of the torsion spring  14  for generating a sliding assist force are then fixed with the fixing pins  15 . This operation completes the assembly of the sliding hinge mechanism. 
         [0060]    In  FIG. 2 , the torsion spring  14  that is disposed essentially below the first housing sliding member  12  cannot be seen partially or entirely and, therefore, is shown by hatching for the purpose of explanation. 
         [0061]    With the sliding hinge mechanism of the present embodiment, when the mechanism is incorporated in a cellular phone, the second housing  2  provided with a liquid crystal display segment is fixedly attached to the second housing sliding member  11 , and the first housing  3  provided with a keyboard is fixedly attached to the first housing sliding member  12 . It goes without saying that the assembly of the housings and the sliding members therefor may be reversed. 
         [0062]      FIG. 2(   a ) shows a first fixing position in which the first housing  3  and the second housing  2  (not shown in the figure) are closed. At this position, the first housing sliding member  12  is pressed by the assist force of the torsion spring  14  to the stoppers  19  disposed on the second housing sliding member  11 . 
         [0063]    Referring to  FIG. 2(   a ), the magnets  16 ,  17  are disposed perpendicular to the sliding movement direction at the sliding members  11 ,  12  for the first and second housings, respectively. Initially the surfaces of the two magnets are disposed parallel to each other so that the north magnetic pole and south magnetic pole can be seen, and then the north magnetic pole and south magnetic pole are disposed facing each other so that an attraction force acts between the magnets disposed between the sliding members  11 ,  12 . Although not shown in the figure, in the magnetic poles of the magnet  16  disposed at the first housing sliding member  12 , the sides facing the magnet  17  are magnetized to south and north poles in reverse to those shown in the figure. 
         [0064]    More specifically, in the magnet  16 , the north pole is disposed on the lower surface side, and in the magnet  17 , the south pole is disposed on the upper surface side. It goes without saying, that the arrangement of magnetic poles may be reversed with respect to that described above. 
         [0065]      FIG. 2(   b ) shows a state in which the first housing  3  and the second housing  2  (not shown in the figure) are at the intermediate third fixing position, an attraction force acts between the magnet  16  disposed at the first housing sliding member  12  and the magnet  17  disposed at the second housing sliding member  11 , and the movement is stopped. In this case, the torsion spring  14  is designed to be positioned at a transition point in which the distance between the attachment positions  20  and  21  is minimal and a maximum load is generated, but the assist force is minimal. 
         [0066]      FIG. 2(   c ) illustrates the second fixing position in which the first housing  3  and the second housing  2  are open. In this state, the first housing sliding member  12  is pressed by the assist force of the torsion spring  14  to the stoppers  19  disposed at the second housing sliding member  11 . The movement is performed in reverse when the configuration is closed. 
       Embodiment 3 
       [0067]      FIG. 3  is a plan schematic drawing illustrating the configuration and movement of the sliding hinge mechanism for a transverse cellular phone in which an intermediate third fixing position is newly disposed in the slidability region by using magnets.  FIG. 3  illustrates a mode of application to a transverse cellular phone with a large and heavy liquid crystal display segment. In this example, four torsion springs and two, left and right, magnet sets are used because large assist force and attraction force in the third fixing position should be ensured. The torsion spring  14  is disposed essentially below the first housing sliding member  12  and not seen at all. However, the torsion spring is shown by hatching for the sake of convenience of explanation. The members having functions identical to those of the members in Embodiment 1 and Embodiment 2 are denoted by reference numerals shown in  FIG. 1  and  FIG. 2 . 
         [0068]      FIG. 3(   a ) shows a state in which the first housing sliding member  12  is disposed at the first fixing position located at a distance A from the central line of the third fixing position.  FIG. 3(   b ) shows a state in which the first housing sliding member  12  is disposed at the intermediate third fixing position.  FIG. 3(   c ) shows a state in which the first housing sliding member  12  is completely open and disposed at the second fixing position at a distance B from the central line of the third fixing position. The slidability region of the hinge shown in  FIG. 3  is (A+B). 
         [0069]    In Embodiment 2, the case is explained in which the first housing sliding member  12  moves with respect to the second housing sliding member  11  to open from the closed position in the sequence of  FIG. 2(   a )®  FIG. 2(   b )®  FIG. 2(   c ) and to close in the reverse sequence. 
         [0070]    Where the arrangement state in which the intermediate third fixing position (b) in  FIG. 3  is closed is taken as a start position, it is possible to provide a new usage mode in which the position of the first housing sliding member  12  shown in  FIG. 3(   a ), which is separated by A from the intermediate first fixing position, is the first fixing position corresponding to the completely open state, or the position of the first housing sliding member  12  shown in  FIG. 3(   c ), which is separated by B from the intermediate first fixing position, is the second fixing position corresponding to the completely open state. 
         [0071]    In  FIG. 3  the case is explained in which the third fixing position is in the center of the sliding region. This third fixing position can be shifted to a new position with different distances A and B by changing the attachment positions of magnets or by changing the arm length, bending angle, and attachment positions of the torsion springs  14 . 
         [0072]    For example, a variation of the arrangement mode of operation sections or the like can be added by enabling the movement from the state shown in  FIG. 5(   c ) to that shown in  FIG. 5(   d ) and from the state shown in  FIG. 5(   c ) to that shown in  FIG. 5(   e ).