Patent Publication Number: US-2023143520-A1

Title: Hinge structure for in-folding type display device

Description:
TECHNICAL FIELD 
     The invention relates to a hinge structure for a display device and, more particularly, to a hinge structure for an in-folding type display device which allows a smartphone to be automatically folded or unfolded with an elastic force of a spring and in which the spring is disposed inside of foldable connecting plates instead of being disposed at positions of a fixing cam and a moving cam, whereby a large space for disposing the spring can be secured to use a spring with a large diameter. 
     BACKGROUND ART 
     Mobile communication terminals are configured to perform various functions. Examples of the functions include a data and speech communication function, a function of capturing a still image or a moving image using a camera, a speech storing function, a function of reproducing a music file using a speaker system, and a function of displaying a still image or a moving image (a video). 
     Some mobile communication terminals have additional functions for playing games, and some mobile communication terminals are embodied as multimedia devices. Recent mobile communication terminals can also receive broadcast or multicast signals and reproduce a video or a television program. 
     Researches for supporting and improving other functions of mobile communication terminals in addition to the above-mentioned functions have been carried out. These researches include modification and improvement of structural constituents of the mobile communication terminals and addition and improvement of software or hardware. 
     In general, a display module of a mobile communication terminal displays information which is processed by the mobile communication terminal. For example, when the mobile communication terminal is in a call mode, the display module displays a user interface (UI) or a graphic user interface (GUI) associated with a call. 
     When the mobile communication terminal is in a video call mode or an image capturing mode, the display module displays a captured or/and received image, a UI, or a GUI. The display module includes a liquid crystal display (LCD), a thin-film transistor liquid crystal display, an organic light emitting diode (OLED), a flexible display, or a 3D display. 
     A flexible display (or a flexible LCD) has been regularly researched with its merit of deformability. It takes much time to use a rolled display like a paper roll as shown in science-fiction movies. 
     Therefore, transitional forms of flexible displays will be many used until the flexible displays are regularly used with sufficient development thereof, and these transitional forms will be similar to current structures of communication terminals. Accordingly, there is necessity for description of usage and protection of flexible displays when such flexible displays are used in mobile communication terminals. 
     An example of such a hinge structure for a mobile communication terminal having a flexible display panel installed therein is disclosed in Korean Patent Application Laid-open No. 10-2015-0096827 (Title of the Invention: HINGE STRUCTURE AND FOLDABLE DISPLAY DEVICE INCLUDING THE SAME). 
     SUMMARY OF INVENTION 
     Technical Problem 
     An objective of the invention is to provide a hinge structure for an in-folding type display device which allows a smartphone to be automatically folded or unfolded with an elastic force of a spring and in which the spring is disposed inside of foldable connecting plates disposed on both sides of a rotating cam and a moving cam instead of being disposed at positions of the rotating cam and the moving cam, whereby a large space for disposing the spring can be secured to use a spring with a large diameter. 
     Solution to Problem 
     In order to achieve the above-mentioned objectives, there is provided a hinge structure for an in-folding type display device, the hinge structure including: a pair of connecting plates that rotates in opposite directions; an elasticity unit that provides an elastic force to rotation of the connecting plates; a plate connecting portion that connects the pair of connecting plates; and an elastic connecting portion that connects the connecting plates and the elasticity unit by causing the elasticity unit to generate an elastic force when the pair of connecting plates rotate. 
     A rotating cam that rotates and a moving cam that moves straightly when the rotating cam rotates may be provided in the plate connecting portion. 
     A rotation link that supports rotation of the connecting plates may be provided in the plate connecting portion. 
     The rotation link may rotate along a rail, and the rail may rotate. 
     A long protrusion longer than the other protrusion may be formed in the rotating cam and the moving cam. 
     A diameter of the elasticity unit may be greater than a diameter of the rotating cam. 
     Advantageous Effects of Invention 
     With the hinge structure for an in-folding type display device according to the invention, it is possible to install a spring with a large diameter and thus to fold and unfold a foldable smartphone with a sufficient elastic force. 
     In a folding hinge according to the related art using a rotating cam and a moving cam, a spring for applying an elastic force is disposed behind the moving cam that moves straightly with rotation of the rotating cam. 
     The diameter of the spring disposed behind the moving cam in the related art is limited by a diameter, a height, a width, or the like of the rotating cam or the moving cam. Accordingly, it is difficult to use a spring with a large diameter and thus the spring which is an elastic member does not provide a large elastic force. 
     When a foldable smartphone is performing a folding or unfolding operation, a battery and the like are mounted in two foldable panels and thus a weight thereof is considerably large. Accordingly, it is necessary to use a spring with a large elastic force in order to smoothly fold or unfold of the panels of the smartphone. 
     According to the invention, since a spring is not disposed behind a moving cam but can be disposed in each of a pair of connecting plates, it is possible to secure a larger space for disposing the spring and thus to use a spring with a larger diameter. Accordingly, it is possible to more smoothly perform a folding or unfolding operation of a smartphone using a spring with a larger elastic force. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view illustrating a state in which a flexible display panel is installed in a display device in which a hinge structure for an in-folding type display device according to the invention is provided. 
         FIG.  2    is a perspective view illustrating a state in which a lower cover is assembled with a hinge in the display device in which the hinge structure for an in-folding type display device according to the invention is provided. 
         FIG.  3    is a perspective view illustrating a state in which the hinge structure is coupled to one upper panel in the display device in which the hinge structure for an in-folding type display device according to the invention is provided. 
         FIG.  4    illustrates a perspective view of the hinge structure in which the upper panels are being folded in the display device in which the hinge structure for an in-folding type display device according to the invention is provided. 
         FIG.  5    illustrates a perspective view of the hinge structure in which the upper panels have been fully folded in the display device in which the hinge structure for an in-folding type display device according to the invention is provided. 
         FIG.  6    illustrates a perspective view of the hinge structure for an in-folding type display device according to the invention. 
         FIG.  7    illustrates an exploded perspective view of the hinge structure for an in-folding type display device according to the invention. 
         FIG.  8    is an exploded perspective view including a state in which a pair of connecting plates are installed in a rotation module in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  9    illustrates a partially exploded perspective view of Parts A, B, and C of the hinge structure for an in-folding type display device according to the invention. 
         FIG.  10    is an exploded perspective view of Part A in  FIG.  9   . 
         FIG.  11    is an exploded perspective view of Part B in  FIG.  9   . 
         FIG.  12    is an exploded perspective view of Part C in  FIG.  9   . 
         FIG.  13    is an exploded perspective view illustrating assembly of four gear fixing cams and a moving cam in a state in which a first rotation unit and a second rotation unit are installed according to the invention. 
         FIG.  14    is an exploded perspective view illustrating the moving cam in a state in which the second rotation unit and four gear fixing cams are assembled according to the invention in  FIG.  13   . 
         FIG.  15    is a perspective view and a plan view separately illustrating the moving cam and the gear fixing cam according to the invention. 
         FIG.  16    is an internal plan view illustrating an internal structure of the hinge structure for an in-folding type display device according to the invention. 
         FIG.  17    is a partial plan view illustrating movement of the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been unfolded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  18    is a perspective view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been unfolded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  19    is a plan view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and the rotation rod in a state in which the connecting plates are being folded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  20    is a plan view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and the rotation rod in a state in which the connecting plates are being folded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  21    is a plan view illustrating movement of the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been fully folded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  22    is a perspective view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been fully folded in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  23    is a cross-sectional front view illustrating movement of a connection gear and an arm gear with movement of the pair of connecting plates in the hinge structure for an in-folding type display device according to the invention. 
         FIG.  24    is an exploded perspective view illustrating another example of the rotation unit module illustrated in  FIG.  10   . 
     
    
    
     REFERENCE SIGNS LIST 
     
         
         
           
               6 : Flexible display panel,  10 : Upper panel 
               14 : Lower cover,  30 : Connecting plate,  50 : Moving cam 
               52 : Connection gear,  53 : Cam,  54 : Arm gear 
               55 : Cam,  56 : Guide groove,  57 : Connection bar 
               59 : Rotation guide,  72 : First rotation link,  75 : Second rotation link 
               150 ,  155 : Long protrusion,  151 ,  156 : Protrusion 
           
         
       
    
     DESCRIPTION OF EMBODIMENTS 
       FIG.  1    is a perspective view illustrating a state in which a flexible display panel is installed in a display device in which a hinge structure for an in-folding type display device according to the invention is provided.  FIG.  2    is a perspective view illustrating a state in which a lower cover is assembled with a hinge in the display device in which the hinge structure for an in-folding type display device according to the invention is provided.  FIG.  3    is a perspective view illustrating a state in which the hinge structure is coupled to one upper panel in the display device in which the hinge structure for an in-folding type display device according to the invention is provided.  FIG.  4    illustrates a perspective view of the hinge structure in which the upper panels are being folded in the display device in which the hinge structure for an in-folding type display device according to the invention is provided.  FIG.  5    illustrates a perspective view of the hinge structure in which the upper panels have been fully folded in the display device in which the hinge structure for an in-folding type display device according to the invention is provided. 
     Referring to  FIGS.  1  to  5   , a hinge structure for an in-folding type display device according to the invention is installed in a central portion in which a pair of upper panels  10  is folded. 
     The upper panels  10  according to the invention are covered by a lower cover  14 . A flexible display panel  6  is installed on the upper panels  10  connected to be folded with the hinge structure according to the invention. 
       FIG.  6    illustrates a perspective view of the hinge structure for an in-folding type display device according to the invention.  FIG.  7    illustrates an exploded perspective view of the hinge structure for an in-folding type display device according to the invention.  FIG.  8    is an exploded perspective view including a state in which a pair of connecting plates are installed in a rotation module in the hinge structure for an in-folding type display device according to the invention.  FIG.  9    illustrates a partially exploded perspective view of Parts A, B, and C of the hinge structure for an in-folding type display device according to the invention. 
     Referring to  FIGS.  6  to  9   , the hinge structure for an in-folding type display device according to the invention includes a pair of connecting plates  30  that is folded in the opposite directions. The connecting plates  30  are connected to the corresponding upper panels  10 . 
     The hinge structure for an in-folding type display device according to the invention is installed in a central case  40 . 
     The hinge structure for an in-folding type display device according to the invention has a configuration in which three parts including Parts A, B, and C illustrated in  FIG.  9    are assembled. 
       FIG.  10    is an exploded perspective view of Part A in  FIG.  9   . 
     Referring to  FIG.  10   , Part A represents a rotation unit module  70  that causes the pair of connecting plates  30  to rotate in the opposite directions. 
     The rotation unit module  70  according to the invention includes a pair of first rotation links  72  that is connected to the pair of connecting plates  30  and rotates therewith, rails  71  that are attached to both side surfaces of the first rotation links  72  such that the first rotation links  70  rotate in a curved shape, and a rotation unit body  73  that is connected to the rails  71 . 
     The rails  71  according to the invention are configured to rotate about a part connected to the rotation unit body  73 . 
       FIG.  11    is an exploded perspective view of Part B in  FIG.  9   . 
     Referring to  FIG.  11   , Part B includes second rotation links  75  that are attached to the connecting plates  30  and rotate with the connecting plates  30 , rotation supports  78  that support the second rotation links  75 , two connection gears  52  that are located at the center and engage, two arm gears  54  that engage with the connection gears  52 , gear connecting portions  77  that support the engagement such that the connection gears  52  and the arm gears  54  rotate, and a moving cam  50  that moves straightly with rotation of the connection gears  52  and the arm gears  54 . 
     Cams  53  and  55  including protrusions and recesses are formed behind the connection gears  52  and the arm gears  54 . Protrusions and recesses are also formed in parts of the moving cam  50  coming into contact with the cams  53  and  55 . 
     In each arm gear  54 , a connection bar  57  that is inserted into and fixed to the corresponding rotation link  75  and a guide groove  56  that is inserted into the rotation guide  59  of the moving cam  59  such that the arm gear  54  rotates along the rotation guide  59  are formed. 
     When the second rotation links  75  coupled to the connecting plates  30  rotate in the opposite directions along with the connecting plates  30  and are folded or unfolded, the connection gears  52  and the arm gears  54  also rotate. 
     The cams  53  and  55  including protrusions and recesses formed behind the connection gears  52  and the arm gears  54  rotate, and the moving cam  50  reciprocates straightly in a direction perpendicular to the rotation direction of the connection gears  52  and the arm gears  54 . 
       FIG.  12    is an exploded perspective view of Part C in  FIG.  9   . 
     Referring to  FIG.  12   , a rotation rod  32  is connected to each connecting plate  30  and is configured to rotate about a position connected to the corresponding connecting plate  30 . 
     Second ends  132  of a pair of rotation rods  32  are configured to come into contact with the moving cam  50 . First ends  131  are configured to rotate about the other end connected to a rod  34  having a spring  36  installed therein. 
     The rod  34  having the spring  36  installed therein is accommodated in an accommodation portion  38  in the corresponding connecting plate  30 . The first ends  131  of the rotation rods  32  and the rods  34  are configured to compress the springs  36  accommodated in the accommodation portions  38  while moving in a direction opposite to the direction in which the moving cam  50  moves when the moving cam  50  moves to be separated away from the connection gears  52  and the arm gears  54 . 
       FIG.  13    is an exploded perspective view illustrating assembly of four gear fixing cams and a moving cam in a state in which a first rotation unit and a second rotation unit are installed according to the invention.  FIG.  14    is an exploded perspective view illustrating the moving cam in a state in which the second rotation unit and four gear fixing cams are assembled according to the invention in  FIG.  13   .  FIG.  15    is a perspective view and a plan view separately illustrating the moving cam and the gear fixing cam according to the invention. 
     Referring to  FIGS.  13  to  15   , rotating cams  53  and  55  including protrusions and recesses are formed in parts in which the connection gears  52  and the arm gears  54  come into contact with the moving cam  50 . 
     Accordingly, when the protrusions of the cams  53  and  55  come into contact with the protrusions of the moving cam  50  while the connection gears  52  and the arm gears  54  are rotating, the moving cam  50  moves straightly in a direction in which it is separated away from the connection gears  52  and the arm gears  54 . 
     Long protrusions  150  and  155  which are formed to be long are formed in parts of the arm gears  54  and the moving cam  50  coming into contact with the arm gears  54 . 
     The long protrusions  150  and  155  can increase an area of the protrusions and extend a period of time in which the protrusions of the moving cam  50  are worn by rotation of the cams  53  and  55 . 
       FIG.  16    is an internal plan view illustrating an internal structure of the hinge structure for an in-folding type display device according to the invention.  FIG.  17    is a partial plan view illustrating movement of the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been unfolded in the hinge structure for an in-folding type display device according to the invention.  FIG.  18    is a perspective view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been unfolded in the hinge structure for an in-folding type display device according to the invention. 
     Referring to  FIGS.  16  to  18   , in a state in which the pair of upper panels  10  of the hinge structure for an in-folding type display device according to the invention has been unfolded, the connection plates  30  connected to the upper panels  10  are also in an unfolded state. 
     When the connecting plates  30  are unfolded, the springs  36  accommodated in the accommodation portions are not compressed. 
       FIG.  19    is a plan view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and the rotation rod in a state in which the connecting plates are being folded in the hinge structure for an in-folding type display device according to the invention.  FIG.  20    is a plan view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and the rotation rod in a state in which the connecting plates are being folded in the hinge structure for an in-folding type display device according to the invention. 
     Referring to  FIGS.  19  and  20   , when a user folds the upper panels  10  by about 45 degrees, the first rotation links  72  and the second rotation links  75  fixed to the connecting plates  30  rotate together. 
     The arm gears  54  connected to the second rotation links  75  rotate, and the connection gears  52  engaging therewith also rotate. 
     When the arm gears  54  and the connection gears  52  rotate, the cams  53  and  55  including protrusions and recesses moves the moving cam  50  in a direction indicated by an arrow while they are rotating. 
     When the protrusions of the cams  53  and  55  and the protrusions of the moving cam  50  come into contact with each other, the moving cam  50  moves to be separated away from the cams  53  and  55  in the direction indicated by the arrow. 
     when the moving cam  50  moves, the moving cam  50  causes the rotation rods  32  to rotate, and the rods  34  compress the springs  36  accommodated in the accommodation portions  38 . 
       FIG.  21    is a plan view illustrating movement of the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been fully folded in the hinge structure for an in-folding type display device according to the invention.  FIG.  22    is a perspective view illustrating movement of the first and second rotation units, the gear fixing cam, the moving cam, and a rotation rod in a state in which the connecting plates have been fully folded in the hinge structure for an in-folding type display device according to the invention. 
     Referring to  FIGS.  21  and  22   , when the user further folds the upper panels  10  by about 45 degrees or greater, the protrusions and the protrusions do not come into contact in the parts in which the cams  53  and  55  and the moving cam  50  come into contact. 
     Accordingly, the moving cam  50  is returned to the original state such that it comes into contact with the connection gears  52  and the arm gears  54  with the restoration force of the compressed springs  36 , the second rotation links  75  connected to the arm gears  54  rotates to be folded while the connection gears  52  and the arm gears  54  rotate, and the connecting plates  30  are fully folded without a force being applied by a user. 
     That is, by the restoration force of the compressed springs  36 , the upper panels  10  are fully folded without a force being applied by a user. 
       FIG.  23    is a cross-sectional front view illustrating movement of a connection gear and an arm gear with movement of the pair of connecting plates in the hinge structure for an in-folding type display device according to the invention. 
     Referring to  FIG.  23   , in a foldable type hinge using a cam according to the related art, springs which are elastic member are located at the positions of the connection gears and the arm gears  52  and  54  or behind the moving cam  50 . Accordingly, the diameter of a coil spring which is used is limited by a diameter (L) or the like of a gear. 
     In the invention, by locating the positions of the springs  36  which are elastic members inside of the connecting plates  30  which are outside of the positions of the gears or the cams, a diameter (K) of a coil spring which is used may be larger than the diameter (L) of the coil spring in the related art. 
     With this configuration, a coil spring with a sufficient elastic force can be used even if the weights of both panels of a foldable smartphone are large. 
       FIG.  24    is an exploded perspective view illustrating another example of the rotation unit module illustrated in  FIG.  10   . 
     Referring to  FIG.  24   , another example of the rotation unit module  70  illustrated in  FIG.  10    includes a pair of first rotation links  172  that are connected to the connecting plates  30  and rotate therewith and a rotation unit body  73  that has an arc-shaped rail groove  171  famed therein such that the first rotation links  172  are inserted thereinto and rotate together. 
     The first rotation links  172  are configured to rotate along the rail grooves  171  formed in an arc shape in the rotation unit body  73 . 
     The rotation unit module according to this example has a configuration in which the first rotation links  172  are directly connected to the rotation unit body  173  and rotate without using the rail  71  illustrated in  FIG.  10   . 
     While an exemplary embodiment of the invention has been described above using specific teams, such description is only for explanation and it is obvious that the embodiment can be modified in various forms without departing from the technical spirit and scope of the appended claims. Such modified embodiments should not be understood separately from the spirit and scope of the invention and should belong to the appended claims.