Patent Publication Number: US-2023142005-A1

Title: Flexible display devices

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national phase of PCT Application No. PCT/CN2021/126501 filed on Oct. 26, 2021, which claims priority to Chinese Patent Application No. 202110287606.8 filed on Mar. 17, 2021, both of which are incorporated herein by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present application relates to the field of display technology, and in particular to a flexible display device. 
     BACKGROUND 
     Rollable flexible display devices have a small volume in a rolled state and are convenient for users to carry, and are widely used in many electronic devices such as mobile communication terminals, tablet computers, e-books, and navigation devices. 
     A flexible display panel of the flexible display device is more flexible, and is prone to unevenness or distortion in an unfolded state, which affects the user experience. 
     SUMMARY 
     Embodiments of the present application provide a flexible display device, including: 
     a flexible display panel having an unrolled state and a rolled state, the flexible display panel including a first end and a second end opposite to the first end;   an auxiliary structure having an unfolded state and a folded state, the auxiliary structure including a third end and a fourth end opposite to the third end, and the fourth end being connected with the second end;   a first reel, connected with the first end; and   a driving unit, where when driving the flexible display panel to switch from the unrolled state to the rolled state and driving the auxiliary structure to switch from the unfolded state to the folded state, the driving unit drives the fourth end to move close to the first reel, and drives the first reel to rotate to drive the second end to move close to the first reel and to wind the flexible display panel around the first reel; and when driving the flexible display panel to switch from the rolled state to the unrolled state and driving the auxiliary structure to switch from the folded state to the unfolded state, the driving unit drives the first reel to rotate to unwind the flexible display panel wound around the first reel from the first reel, and drives the fourth end to move away from the first end to drive the second end to move away from the first reel.   

     In an embodiment, the auxiliary structure includes a rod portion, the flexible display device further includes a fixed shaft, and the rod portion is rotatable around the shaft; and 
     [ 10 ] when driving the auxiliary structure to switch to the unfolded state, the driving unit drives the rod portion to rotate around the shaft to move a fourth end of the rod portion away from the first reel; and when driving the auxiliary structure to switch to the folded state, the driving unit drives the rod portion to rotate around the shaft to move the fourth end of the rod portion close to the first reel. 
     [ 11 ] In an embodiment, the flexible display device further includes a connecting rod provided with a straight slot, and the fourth end of the rod portion is movably and rotatably connected with the straight slot; and the second end is connected with the connecting rod, and the fourth end of the rod portion is connected with the second end through the connecting rod; and 
     [ 12 ] when the fourth end of the rod portion moves away from or close to the first reel, the fourth end of the rod portion moves and rotates relative to the straight slot, to drive the connecting rod to move away from or close to the first reel. 
     In an embodiment, the rod portion is provided with a strip-shaped slot, the shaft passes through the strip-shaped slot, and the strip-shaped slot is movable and rotatable relative to the shaft; 
     when driving the auxiliary structure to switch to the folded state, the driving unit drives the strip-shaped slot to rotate and move relative to the shaft to increase a distance between a third end of the rod portion and the shaft, so as to drive the fourth end of the rod portion to move close to the first reel; and   when driving the auxiliary structure to switch to the unfolded state, the driving unit drives the strip-shaped slot to rotate and move relative to the shaft to decrease the distance between the third end of the rod portion and the shaft, so as to drive the fourth end of the rod portion to move away from the first reel.   

     In an embodiment, in an extension direction of the rod portion, a distance between an end of the strip-shaped slot close to the third end of the rod portion and the third end of the rod portion is smaller than a distance between an end of the strip-shaped slot away from the third end of the rod portion and the fourth end of the rod portion. 
     In an embodiment, the rod portion includes a first rod portion and a second rod portion that cross each other, and the shaft passes through the strip-shaped slot of the first rod portion and the strip-shaped slot of the second rod portion; 
     when driving the auxiliary structure to switch to the folded state, the driving unit drives the strip-shaped slot of the first rod portion and the strip-shaped slot of the second rod portion to rotate and move relative to the shaft to increase a distance between a third end of the first rod portion and the shaft, a distance between a third end of the second rod portion and the shaft, and a distance between the third end of the first rod portion and the third end of the second rod portion, so as to drive a fourth end of the first rod portion and a fourth end of the second rod portion to move close to the first reel; and   when driving the auxiliary structure to switch to the unfolded state, the driving unit drives the strip-shaped slot of the first rod portion and the strip-shaped slot of the second rod portion to rotate and move relative to the shaft to decrease the distance between the third end of the first rod portion and the shaft, the distance between the third end of the second rod portion and the shaft, and the distance between the third end of the first rod portion and the third end of the second rod portion, so as to drive the fourth end of the first rod portion and the fourth end of the second rod portion to move away from the first reel.   

     [ 20 ] In an embodiment, the driving unit includes a first motor, a transmission member and a connector, the connector is rotatably connected with a third end of the rod portion, and the connector is cooperated with the transmission member; and 
     the first motor drives the transmission member to rotate, the transmission member drives the connector to move relative to the shaft, and the connector drives the third end of the rod portion to move relative to the shaft. 
     In an embodiment, the flexible display device further includes an accommodating unit, in which the shaft, the first reel, and the third end are accommodated; and 
     the flexible display device further includes a jointing rod that is fixedly connected with the shaft, and the shaft is fixedly mounted in the accommodating unit through the jointing rod; and at least two mounting holes are provided in the jointing rod, the flexible display device further includes connecting pieces corresponding to the mounting holes one-to-one, and each of the connecting pieces passes through a respective mounting hole to fix the jointing rod in the accommodating unit. 
     In an embodiment, the flexible display device further includes a flexible backplane having an unrolled state and a rolled state; and the driving unit drives the flexible backplane to switch between the rolled state and the unrolled state; and 
     when the flexible backplane and the flexible display panel are in the unrolled state, the auxiliary structure is located between the flexible backplane and the flexible display panel. 
     In an embodiment, the flexible display device further includes a second reel, and the driving unit includes a power assembly including a second motor, a first gear, and a second gear; an end of the flexible backplane is connected with the second reel; the first gear engages with the second gear, the first gear drives the first reel to rotate, and the second gear drives the second reel to rotate; and the second motor drives one of the first gear and the second gear to rotate; and 
     the second motor operates to drive the first gear and the second gear to rotate, and in turn drive the first reel and the second reel to rotate, to wind the flexible display panel in the unrolled state around the first reel, and to wind the flexible backplane in the unrolled state around the second reel, or to unwind the flexible display panel wound around the first reel from the first reel, and to unwind the flexible backplane wound around the second reel from the second reel. 
     In an embodiment, the flexible display device further includes zipper assemblies respectively provided on opposite sides of the flexible display panel; each of the zipper assemblies includes a first zipper chain, a second zipper chain, and a fixed lock catch, the first zipper chain is disposed on a side edge of the flexible display panel, and the second zipper chain is disposed on a side edge of the flexible backplane; 
     when simultaneously driving the flexible display panel and the flexible backplane to switch from the unrolled state to the rolled state, the driving unit drives the first zipper chain and the second zipper chain to roll so as to move relative to the lock catch, such that the lock catch separates the first zipper chain and the second zipper chain in a fastened state; and   when simultaneously driving the flexible display panel and the flexible backplane to switch from the rolled state to the unrolled state, the driving unit drives the first zipper chain and the second zipper chain in a rolled state to unroll so as to move relative to the lock catch, such that the lock catch fastens the first zipper chain and the second zipper chain.   

     In an embodiment, the flexible display device further includes an accommodating unit, in which the first reel and the third end are accommodated; and 
     when the flexible display panel is in the rolled state and the auxiliary structure is in the folded state, the flexible display panel, the driving unit and the auxiliary structure are accommodated in the accommodating unit; and when the flexible display panel is in the unrolled state and the auxiliary structure is in the unfolded state, the flexible display panel and the auxiliary structure are at least partially exposed from the accommodating unit, and the driving unit is accommodated in the accommodating unit. 
     Embodiments of the present application mainly provide the following technical effects. 
     With the flexible display device according to the embodiments of the present application, when the driving unit drives the flexible display panel to switch to the unrolled state and drives the auxiliary structure to switch to the unfolded state, the fourth end of the auxiliary structure drives the second end of the flexible display panel to move away from the first reel, resulting in a high evenness of the flexible display panel in the unrolled state, which can avoid unevenness or distortion of the flexible display panel during unrolling due to its high flexibility, and help to improve the user experience. When the driving unit drives the flexible display panel to switch to the rolled state and drives the auxiliary structure to switch to the folded state, the flexible display panel is wound around the first reel, which can make the flexible display device smaller in volume and convenient for users to carry. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic structural diagram of a flexible display device according to an exemplary embodiment of the present application when a flexible display panel is in an unrolled state. 
         FIG.  2    is a schematic structural diagram of a flexible display device according to an exemplary embodiment of the present application when a flexible display panel is in a rolled state. 
         FIG.  3    is a schematic structural diagram of an auxiliary structure according to an exemplary embodiment of the present application in an unfolded state. 
         FIG.  4    is a schematic structural diagram of an auxiliary structure according to an exemplary embodiment of the present application in a folded state. 
         FIG.  5    is a schematic exploded view of a structure of a flexible display device according to an exemplary embodiment of the present application. 
         FIG.  6    is a schematic diagram of a partial structure of a flexible display device according to an exemplary embodiment of the present application. 
         FIG.  7    is a schematic diagram of a partial structure of a flexible display device according to an exemplary embodiment of the present application. 
         FIG.  8    is a schematic diagram of a partial structure of a flexible display device according to an exemplary embodiment of the present application. 
         FIG.  9    is an enlarged view of an area A in  FIG.  8   . 
         FIG.  10    is a schematic structural diagram of a flexible display device according to an exemplary embodiment of the present application. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments will be described in detail herein, and examples thereof are illustrated in the drawings. When the following description relates to the drawings, the same numbers in different drawings indicate the same or similar elements, unless otherwise indicated. Embodiments described in the following exemplary embodiments do not represent all embodiments in accordance with the present application. Rather, they are merely examples of apparatuses and methods in accordance with some aspects of the present application as detailed in the appended claims. 
     Terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. Singular forms of “a”, “said”, and “the” used in the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and/or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items. 
     It should be understood that though terms “first”, “second”, “third”, etc. may be used in the present application to describe various information, such information should not be limited by these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word “if” as used herein may be interpreted as “when”, “upon” or “in response to determining”. 
     Embodiments of the present application provide a flexible display device. The flexible display device in the embodiments of the present application will be described in detail below in conjunction with the drawings. Features in the embodiments described below may complement each other or be combined with each other without conflict. 
     Embodiments of the present application provide a flexible display device. Referring to  FIGS.  1  to  5   , the flexible display device  100  includes a flexible display panel  10 , an auxiliary structure  20 , a first reel  325 , and a driving unit  30 . 
     The flexible display panel  10  has an unrolled state and a rolled state. In the flexible display device  100  shown in  FIG.  1   , the flexible display panel  10  is in the unrolled state, and the flexible display device may be in a display state at this time. In the flexible display device  100  shown in  FIG.  2   , the flexible display panel  10  is in the rolled state. The flexible display panel  10  includes a first end  11  and a second end  12  opposite to the first end  11 . 
     The auxiliary structure  20  has an unfolded state and a folded state. The auxiliary structure  20  includes a third end and a fourth end opposite to the third end, and the fourth end is connected with the second end  12 . In the flexible display device  100  shown in  FIGS.  1  and  3   , the auxiliary structure  20  is in the unfolded state. In the flexible display device  100  shown in  FIGS.  2  and  4   , the auxiliary structure  20  is in the folded state. 
     The first reel  325  is connected with the first end  11 . When driving the flexible display panel  10  to switch from the unrolled state to the rolled state and driving the auxiliary structure  20  to switch from the unfolded state to the folded state, the driving unit  30  drives the fourth end of the auxiliary structure  20  to move close to the first reel  325 , and drives the first reel  325  to rotate to drive the second end  12  to move close to the first reel  325  and to wind the flexible display panel  10  around the first reel  325 . It should be noted that the rotation of the first reel  325  and the movement of the fourth end of the auxiliary structure  20  close to the first reel  325  may both drive the second end of the flexible display panel to move close to the first reel  325 . When driving the flexible display panel  10  to switch from the rolled state to the unrolled state and driving the auxiliary structure  20  to switch from the folded state to the unfolded state, the driving unit  30  drives the first reel  325  to rotate to unwind the flexible display panel  10  wound around the first reel  325  from the first reel  325 , and drives the fourth end to move away from the first end  11  to drive the second end  12  to move away from the first end  11 . 
     With the flexible display device  100  according to the embodiments of the present application, when the driving unit  30  drives the flexible display panel  10  to switch to the unrolled state and drives the auxiliary structure  20  to switch to the unfolded state, the fourth end of the auxiliary structure  20  drives the second end  12  of the flexible display panel  10  to move away from the first reel  325 , and the auxiliary structure  20  applies a tensile force to the flexible display panel  10 , resulting in a high evenness of the flexible display panel in the unrolled state, which can avoid unevenness or distortion of the flexible display panel during unrolling due to its high flexibility, and help to improve the user experience. When the driving unit  30  drives the flexible display panel  10  to switch to the rolled state and drives the auxiliary structure  20  to switch to the folded state, the flexible display panel  10  is wound around the first reel  325 , which can make the flexible display device  100  smaller in volume and convenient for users to carry. 
     A distance between the third end of the auxiliary structure  20  and the first reel  325  is small. The auxiliary structure  20  includes a rod portion  201  (which will be described in detail below). In the unfolded state of the auxiliary structure  20 , a distance between a third end of the rod portion  201  and the first reel  325  is smaller than a distance between a fourth end of the rod portion  201  and the first reel  325 . The auxiliary structure  20  is made of a hard material. 
     In an embodiment, in the unfolded state of the auxiliary structure  20 , only the first end of the flexible display panel  10  is connected with the first reel  325 , and other areas of the flexible display panel  10  are all separated from the first reel  325 . A distance between the fourth end of the auxiliary structure  20  and the first reel  325  is equal to a size of the flexible display panel  10  in a second direction (which will be described later) in the unrolled state thereof, such that the flexible display panel  10  has a high evenness without wrinkles in the unrolled state thereof. 
     The first end  11  of the flexible display panel  10  is connected with the first reel  325 . The first reel  325  rotates to wind the flexible display panel  10  around the first reel  325 , or to unwind the flexible display panel  10  from the first reel  325 . The second end  12  of the flexible display panel  10  is driven to move by the cooperation between the auxiliary structure  20  and the first reel  325 , thereby enabling the flexible display panel  10  to be switched between the unrolled state and the rolled state. A rotation direction of the first reel  325  when the flexible display panel  10  is switched from the rolled state to the unrolled state is opposite to a rotation direction of the first reel  325  when the flexible display panel  10  is switched from the unrolled state to the rolled state. 
     The flexible display panel  10  has a fixed size in an extension direction of the flexible display panel  10  at the first end  11  (hereinafter referred to as a first direction), when the flexible display panel  10  is in the unrolled state and in the rolled state. In an extension direction of a side edge of the flexible display panel  10  in the unrolled state (hereinafter referred to as a second direction, which is perpendicular to the first direction), the flexible display panel  10  has different sizes in the unrolled state and in the rolled state. The size of the flexible display panel  10  in the second direction when in the rolled state is smaller than that of the flexible display panel  10  in the second direction when in the unrolled state. Space occupied by the flexible display panel  10  in the unrolled state is more than that occupied by the flexible display panel  10  in the rolled state. A size of the auxiliary structure  20  in the second direction when in the unfolded state is larger than that of the auxiliary structure  20  in the second direction when in the folded state. Space occupied by the auxiliary structure  20  in the unfolded state is more than that occupied by the auxiliary structure  20  in the folded state. 
     In an embodiment, the flexible display device  100  further includes an accommodating unit  40 . The first reel  325 , the driving unit  30 , and the third end of the auxiliary structure  20  may always be accommodated in the accommodating unit  40 . When the flexible display panel  10  is in the rolled state and the auxiliary structure  20  is in the folded state, the flexible display panel  10 , the driving unit  30 , and the auxiliary structure  20  are accommodated in the accommodating unit  40 . When the flexible display panel  10  is in the unrolled state and the auxiliary structure  20  is in the unfolded state, the flexible display panel  10  and the auxiliary structure  20  are at least partially exposed from the accommodating unit  40 . In this way, when the flexible display device is not displaying, the flexible display panel  10 , the driving unit  30 , and the auxiliary structure  20  are accommodated in the accommodating unit  40 . The driving unit  30  is accommodated in the accommodating unit when the flexible display device is not displaying, which helps to improve the aesthetics of the flexible display device  100 . The accommodating unit  40  may be provided with an opening through which the flexible display panel  10  and the auxiliary structure  20  are exposed from the accommodating unit  40 . And, the first end of the flexible display panel  10  is always accommodated in the accommodating unit  40 , and the second end moves relative to the accommodating unit  40  to enable the switch between the unrolled state and the rolled state, that is, the flexible display panel is enabled to switch between the unrolled state and the rolled state by moving to one side. 
     In an embodiment, the accommodating unit  40  is assembled from a first housing  41  and a second housing  42 . This facilitates the mounting of the driving unit  30 , the third end of the auxiliary structure  20 , the first reel  325 , and the first end of the flexible display panel  10  in the accommodating unit  40 , thereby reducing the complexity of assembly. 
     In an embodiment, referring to  FIG.  5   , the flexible display device  100  further includes a fixed shaft  50 , the shaft  50  may be fixedly mounted in the accommodating unit  40 , and the shaft  50  is not rotatable and movable relative to the accommodating unit  40 . The flexible display device  100  further includes a jointing rod  51  fixedly connected with the shaft  50 , and the shaft  50  is fixedly mounted in the accommodating unit  40  through the jointing rod  51 . The jointing rod  51  may be provided with at least two mounting holes, the flexible display device  100  further includes connecting pieces corresponding to the mounting holes one-to-one, and each connecting piece passes through a respective mounting hole to fix the jointing rod  51  in the accommodating unit  40 . The connecting piece may be, for example, a screw. In some embodiments, the shaft  50  is fixed to the first housing  41  of the accommodating unit  40  through the jointing rod  51 . The jointing rod  51  may be provided with two mounting holes. 
     The auxiliary structure  20  includes the rod portion  201  which is rotatable around the shaft  50 . The third end of the rod portion  201  is connected with the driving unit  30 . The third end of the rod portion  201  is close to the first end of the flexible display panel  10 . The auxiliary structure includes the rod portion  201  which includes the third end and the fourth end. 
     When the driving unit  30  drives the auxiliary structure  20  to switch to the unfolded state, the rod portion  201  is driven to rotate around the shaft  50  such that the fourth end of the rod portion  201  moves away from the first reel  325 . When the driving unit drives the auxiliary structure  20  to switch to the folded state, the rod portion  201  is driven to rotate around the shaft  50  such that the fourth end of the rod portion  201  moves close to the first reel  325 . 
     When the flexible display panel  10  is switched to the unrolled state and the auxiliary structure  20  is switched to the unfolded state, the fourth end of the rod portion  201  drives the second end  12  of the flexible display panel  10  to move away from the first reel  325 , such that the flexible display panel  10  may be unrolled. In this way, the rod portion  201  has an increased size in the second direction, which drives an increase in the size of the flexible display panel  10  in the second direction, such that the flexible display panel  10  may have a high evenness in the unrolled state. When the flexible display panel  10  is switched to the rolled state and the auxiliary structure  20  is switched to the folded state, the fourth end of the rod portion  201  moves close to the first reel  325 , while the second end  12  of the flexible display panel  10  moves close to the first reel  325 , such that the sizes of both the flexible display panel  10  and the rod portion  201  in the second direction may be reduced, thereby reducing the volume of the flexible display device. 
     In an embodiment, the auxiliary structure  20  includes at least two rod portions  201 . In this way, the fourth ends of the two rod portions  201  together drive the second end  12  of the flexible display panel  10  to move, which is more helpful to improve the evenness of the flexible display panel  10  in the unrolled state. 
     In an embodiment, the flexible display device  100  further includes a connecting rod  321  provided with a straight slot  327 , and the fourth end of the rod portion  201  is movably and rotatably connected with the straight slot  327 . The second end  12  is connected with the connecting rod  321 , and the fourth end of the rod portion  201  is connected with the second end  12  through the connecting rod  321 . As the fourth end of the rod portion  201  moves away from or close to the first reel  325 , the fourth end of the rod portion  201  moves and rotates relative to the straight slot  327 . The straight slot  327  extends in the same direction as the connecting rod  321 . The connecting rod  321  is made of an inflexible material such as metal or plastic. 
     In this way, when the fourth end of the rod portion  201  moves away from or close to the first reel  325 , the fourth end of the rod portion  201  moves and rotates relative to the connecting rod  321  to drive the connecting rod  321  to move away from or close to the first reel  325 , and the second end of the flexible display panel  10  moves along with the connecting rod  321 . Since the second end  12  is connected with the connecting rod  321 , the second end of the flexible display panel  10  may not move relative to the connecting rod  321  when the rod portion  201  moves relative to the connecting rod  321 , and the flexible display panel may not wrinkle, which can avoid wrinkles of the flexible display panel  10  due to movement of the rod portion  201  when the fourth end is directly connected with the second end  12 . 
     In an embodiment, the rod portion  201  is provided with a strip-shaped slot through which the shaft  50  passes, and the strip-shaped slot is movable and rotatable relative to the shaft  50 . When driving the auxiliary structure  20  to switch to the folded state, the driving unit  30  drives the strip-shaped slot to rotate and move relative to the shaft, such that the distance between the third end of the rod portion  201  and the shaft  50  increases, which drives the fourth end of the rod portion  201  to move close to the first reel  325 . When driving the auxiliary structure  20  to switch to the unfolded state, the driving unit  30  drives the strip-shaped slot to rotate and move relative to the shaft  50 , such that the distance between the third end of the rod portion  201  and the shaft  50  decreases, which drives the fourth end of the rod portion  201  to move away from the first reel  325 . 
     By providing the strip-shaped slot in the rod portion  201 , the distance between the shaft  50  and the third end of the rod portion  201  increases and the distance between the shaft  50  and the fourth end of the rod portion  201  decreases when the auxiliary structure  20  is switched to the folded state, such that a distance between the third end or the fourth end of the rod portion  201  and an edge of the flexible display panel on the same side may be smaller. This can avoid a larger volume of the flexible display device in the rolled state due to a large distance between the third end or the fourth end of the rod portion  201  and an edge of the flexible display panel on the same side, which helps to reduce the volume of the flexible display device when the flexible display panel is in the rolled state. 
     In an embodiment, in an extension direction of the rod portion  201 , a distance between an end of the strip-shaped slot close to the third end of the rod portion  201  and the third end of the rod portion  201  is smaller than a distance between an end of the strip-shaped slot away from the third end of the rod portion  201  and the fourth end of the rod portion  201 . When the auxiliary structure  20  is switched to the unfolded state, the strip-shaped slot moves relative to the shaft  50 , such that the end of the strip-shaped slot close to the third end moves close to the shaft  50 . By setting the distance between the end of the strip-shaped slot close to the third end of the rod portion  201  and the third end of the rod portion  201  to be smaller than the distance between the end of the strip-shaped slot away from the third end of the rod portion  201  and the fourth end of the rod portion  201 , the distance between the fourth end of the rod portion  201  and the shaft  50  may be relatively large when the auxiliary structure is in the unfolded state, such that an area of the flexible display panel in the unrolled state increases to increase a size of a display area of the flexible display panel. 
     In an embodiment, when the auxiliary structure  20  is in the unfolded state, the shaft  50  is pressed against the end of the strip-shaped slot close to the third end. In this way, the distance between the fourth end of the rod portion  201  and the shaft  50  may be maximized. 
     In an embodiment, a distance between the end of the strip-shaped slot away from the third end of the rod portion  201  and the fourth end of the rod portion  201  is approximately equal to a distance between the end of the strip-shaped slot away from the third end of the rod portion  201  and the third end of the rod portion  201 . When the auxiliary structure  20  is in the folded state, the end of the strip-shaped slot away from the third end of the rod portion  201  is pressed against the shaft  50 . Distances from the shaft  50  to two ends of the first reel  325  may be the same. In this way, when the auxiliary structure  20  is in the folded state, the distance from the third end of the rod portion  201  to the shaft  50  is equal to the distance from the fourth end of the rod portion  201  to the shaft  50 , which helps to reduce the volume of the flexible display device in the rolled state. 
     In an embodiment, referring to  FIG.  6   , the auxiliary structure  20  includes a first rod portion  21  and a second rod portion  22  that cross each other. The first rod portion  21  includes a third end  211  and a fourth end  212  opposite to the third end, and the first rod portion  21  is provided with a strip-shaped slot  213 . The second rod portion  22  includes a third end  221  and a fourth end  222  opposite to the third end, and the second rod portion  22  is provided with a strip-shaped slot  223 . The shaft  50  passes through the strip-shaped slot  213  of the first rod portion  21  and the strip-shaped slot  223  of the second rod portion  22 , and the strip-shaped slot  213  of the first rod portion  21  and the strip-shaped slot  223  of the second rod portion  22  are movable and rotatable relative to the shaft  50 . 
     When driving the auxiliary structure  20  to switch to the folded state, the driving unit  30  drives the strip-shaped slot  213  of the first rod portion  21  and the strip-shaped slot  223  of the second rod portion  22  to rotate and move relative to the shaft  50 , such that a distance between the third end  211  of the first rod portion  21  and the shaft  50  and a distance between the third end  221  of the second rod portion  22  and the shaft  50  increase, a distance between the third end  211  of the first rod portion  21  and the third end  221  of the second rod portion  22  increases, and the fourth end  212  of the first rod portion  21  and the fourth end  222  of the second rod portion  22  move close to the first end  11 . 
     When driving the auxiliary structure  20  to switch to the unfolded state, the driving unit  30  drives the strip-shaped slot  213  of the first rod portion  21  and the strip-shaped slot  223  of the second rod portion  22  to rotate and move relative to the shaft  50 , such that the distance between the third end  211  of the first rod portion  21  and the shaft  50  and the distance between the third end  221  of the second rod portion  22  and the shaft  50  decrease, the distance between the third end  211  of the first rod portion  21  and the third end  221  of the second rod portion  22  decreases, and the fourth end  212  of the first rod portion  21  and the fourth end  222  of the second rod portion  22  move away from the first reel  325 . 
     By providing the first rod portion  21  and the second rod portion  22  that cross each other, the fourth end of the first rod portion  21  and the fourth end of the second rod portion  22  are both connected with the connecting rod  321 . When the auxiliary structure  20  is switched to the unfolded state, the distance between the fourth end of the first rod portion  21  and the fourth end of the second rod portion  22  decreases, and the fourth end of the first rod portion  21  and the fourth end of the second rod portion  22  together drive the connecting rod  321  to move away from the first reel  325  by substantially the same distance at both ends of the connecting rod  321 , further ensuring the evenness of the flexible display panel. 
     In an embodiment, when the flexible display panel  10  is in the rolled state and the auxiliary structure  20  is in the folded state, the third end  211  of the first rod portion  21 , the fourth end  212  of the first rod portion  21 , the third end  221  of the second rod portion  22 , and the fourth end  222  of the second rod portion  22  may not extend beyond the edge of the flexible display panel  10  on the same side. In this way, when the flexible display panel is in the rolled state, the flexible display device has a smaller size in the first direction, and the volume of the flexible display device is reduced. 
     In an embodiment, when the flexible display panel  10  is in the unrolled state and the auxiliary structure  20  is in the unfolded state, the end of the strip-shaped slot  213  of the first rod portion  21  close to the third end of the first rod portion  21  is pressed against the shaft  50 , and the end of the strip-shaped slot  223  of the second rod portion  22  close to the third end of the second rod portion  22  is pressed against the shaft  50 . When the flexible display panel  10  is in the rolled state and the auxiliary structure  20  is in the folded state, the end of the strip-shaped slot  213  of the first rod portion  21  away from the third end of the first rod portion  21  is pressed against the shaft  50 , and the end of the strip-shaped slot  223  of the second rod portion  22  away from the third end of the second rod portion  22  is pressed against the shaft  50 . This helps to prevent the strip-shaped slot  213  of the first rod portion  21  and the strip-shaped slot  223  of the second rod portion  22  from moving relative to the shaft  50 , thereby avoiding an influence on the evenness of the flexible display panel due to the movement of the first rod portion  21  and the second rod portion  22  relative to the shaft  50 . 
     In an embodiment, referring to  FIG.  7   , the connecting rod  321  is provided with two straight slots  327  arranged at intervals, and the fourth end of the first rod portion  21  is rotatably and movably connected to one straight slot  327 , and the fourth end of the second rod portion  22  is rotatably and movably connected to the other straight slot  327 . When the flexible display panel  10  is switched to the unrolled state and the auxiliary structure  20  is switched to the unfolded state, the fourth end  212  of the first rod portion  21  and the fourth end  222  of the second rod portion  22  drive the connecting rod  321  to move away from the first end  11 , while the fourth end  212  of the first rod portion  21  and the fourth end  222  of the second rod portion  22  move and rotate in the corresponding straight slots  327 , such that the distance between the fourth end  212  of the first rod portion  21  and the fourth end  222  of the second rod portion  22  decreases. 
     In an embodiment, the fourth end of the first rod portion  21  and the fourth end of the second rod portion  22  are each connected with the connecting rod  321  through a connecting structure  328 . The connecting structure  328  includes a connecting post and two limiting stoppers provided on the connecting post. The connecting rod  321  has a hollow structure and is open on a side toward the first reel. The fourth end of the first rod portion  21  and the fourth end of the second rod portion  22  are inserted into the connecting rod  321  through the opening in the connecting rod  321 . The connecting post of the connecting structure  328  passes through the straight slot  327  and a mounting hole provided on the fourth end of the first rod portion  21 , and both ends of the connecting post are exposed with the two limiting stoppers respectively provided on the connecting post on both sides of the connecting rod  321 . The connecting post is movable and rotatable in the straight slot  327 , such that the connecting structure  328  connects the fourth end of the first rod portion  21  with the connecting rod  321 , and the fourth end of the first rod portion  21  is rotatable and movable relative to the connecting rod  321 . The fourth end of the second rod portion  22  is connected with the connecting rod  321  through the connecting structure  328  in the same manner. 
     In an embodiment, referring to  FIG.  5    and  FIG.  6    again, the driving unit  30  includes a first motor  311 , a transmission member  312  and a connector  313 , the connector  313  is rotatably connected with the third end of the rod portion  201 , and the connector  313  is cooperated with the transmission member  312 . The first motor  311  drives the transmission member  312  to rotate, and the transmission member  312  drives the connector  313  to move relative to the shaft  50 , such that the connector  313  drives the third end of the rod portion  201  to move relative to the shaft  50 . In detail, the connector  313  drives the third end of the rod portion  201  to move and rotate relative to the shaft  50 . 
     In an embodiment, the transmission member  312  is a screw rod, which extends in a direction substantially flush with an extension direction of the first end  11 . The connector  313  may be threadedly connected with the screw rod. The first motor  311  drives the screw rod to rotate, and the rotation of the screw rod drives the connector  313  to move along the screw rod, thereby driving the third end of the rod portion  201  to rotate relative to the shaft  50 . 
     In an embodiment, the driving unit  30  includes two sub-drive assemblies  31 , one of which drives the first rod portion  21  to move, and the other drives the second rod portion  22  to move. Each sub-drive assembly  31  includes the first motor  311 , the transmission member  312  and the connector  313 . 
     In an embodiment, the first motor  311  and the transmission member  312  are fixed on an inner wall of the first housing  41 . This may prevent movement of the first motor  311  and the transmission member  312  from affecting the operation of the flexible display device. 
     In an embodiment, the driving unit  30  includes a power assembly  32  connected with the first reel  325  to drive the first reel  325  to rotate. An end of the auxiliary structure  20  and the second end  12  are each connected with the connecting rod  321 . 
     In an embodiment, referring to  FIGS.  5 ,  8  and  9   , the power assembly  32  includes a second motor  324 . The second motor  324  rotates the first reel  325 , to wind the flexible display panel  10  in the unrolled state around the first reel  325 , or unwind the flexible display panel  10  wound around the first reel  325  from the first reel  325 . 
     In this way, the power assembly has a relatively simple structure and is easy to implement. 
     In an embodiment, the flexible display device further includes a flexible backplane  60  having an unrolled state and a rolled state. The driving unit  30  drives the flexible backplane  60  to switch between the rolled state and the unrolled state. When the flexible backplane  60  and the flexible display panel  10  are in the unrolled state, the auxiliary structure  20  is located between the flexible backplane  60  and the flexible display panel  10 . By providing the flexible backplane  60 , when the flexible display panel  10  and the flexible backplane  60  are in the unrolled state, the auxiliary structure  20  is located between the flexible backplane  60  and the flexible display panel  10 , and the auxiliary structure  20  is not exposed to the outside, which can improve the aesthetics of the flexible display device and improve the user experience. The driving unit  30  may simultaneously drive the flexible display panel  10  and the flexible backplane  60  to switch to the rolled state, and the arrangement of the flexible backplane  60  may not increase the volume of the flexible display device. 
     In an embodiment, when the flexible backplane  60  is in the rolled state, the flexible backplane  60  is accommodated in the accommodating unit  40 . 
     In an embodiment, the power assembly  32  simultaneously drives the flexible display panel  10  and the flexible backplane  60  to switch between the unrolled state and the rolled state. The flexible display device further includes a second reel  326 . The second reel  326  is accommodated in the accommodating unit  40 . The power assembly  32  further includes a first gear  322  and a second gear  323 , and an end of the flexible backplane  60  is connected with the second reel  326 . The first gear  322  engages with the second gear  323 , the first gear  322  drives the first reel  325  to rotate, and the second gear  323  drives the second reel  326  to rotate. The second motor  324  drives one of the first gear  322  and the second gear  323  to rotate. 
     Since the first gear  322  engages with the second gear  323 , when the second motor  324  drives one of the first and second gears to rotate, the gear drives the other gear to rotate, and the first gear  322  and the second gear  323  rotate in opposite directions. In the illustrated embodiment, the second motor  324  is connected with the second gear  323  through a conveyor belt, the second motor  324  drives the second gear  323  to rotate through the conveyor belt, and the rotation of the second gear  323  drives the first gear  322  to rotate. In other embodiments, the second motor  324  may rotate the first gear  322  through the conveyor belt. 
     When the second motor  324  is in operation, the first gear  322  and the second gear  323  rotate, to drive the first reel  325  and the second reel  326  to rotate, to wind the flexible display panel  10  in the unrolled state around the first reel  325 , and to wind the flexible backplane  60  in the unrolled state around the second reel  326 , or to unwind the flexible display panel  10  wound around the first reel  325 , and to unwind the flexible backplane  60  wound around the second reel  326 . 
     In this way, a single second motor  324  may drive both the flexible backplane  60  and the flexible display panel  10  to unroll or roll simultaneously, which can simplify the structural complexity of the driving unit  30  and reduce the cost of the flexible display device. 
     In an embodiment, the flexible display device may be provided with two first gears  322  and two second gears  323 . The two first gears  322  are respectively connected to both ends of the first reel  325 , and the two second gears  323  are respectively connected to both ends of the second reel  326 . An extension direction of the first reel  325  may be the same as that of the second reel  326 . 
     In an embodiment, the second motor  324 , the first gear  322  and the second gear  323  may be fixedly mounted on an inner wall of the second housing  42  to prevent the second motor  324 , the first gear  322  and the second gear  323  from moving relative to the second housing  42 . 
     In an embodiment, when the flexible display panel is driven to switch to the rolled state and the auxiliary structure  20  is driven to switch to the folded state, the operation time of the first motor  311  and the second motor  324  may be controlled such that the operation time of the first motor  311  is slightly earlier than the operation time of the second motor  324 . In this way, the connecting rod  321  first moves close to the first reel  325 , and then the first reel  325  rotates to rotate the flexible display panel, such that the connecting rod  321  applies a tensile force to the second end of the flexible display panel  10 , to ensure the evenness of each part of the flexible display panel when in the rolled state, and to prevent the flexible display panel from wrinkling. 
     In an embodiment, one end of the flexible backplane  60  is connected to the second reel  326 , and the other end of the flexible backplane  60  is connected to the connecting rod  321 . The flexible backplane  60  may be bonded to a side of the connecting rod  321  by an adhesive material. In this way, when the fourth ends of the first rod portion  21  and the second rod portion  22  move away from the flexible display panel  10 , the flexible backplane  60  is driven to move, such that the flexible backplane  60  may be smoothly unrolled to prevent the flexible backplane  60  from wrinkling. 
     In an embodiment, referring to  FIG.  8    and  FIG.  9    again, the flexible display device  100  further includes zipper assemblies  70  respectively provided on opposite sides of the flexible display panel. The zipper assembly  70  includes a first zipper chain  72 , a second zipper chain  73 , and a fixed lock catch  71 , the first zipper chain  72  is disposed on a side edge of the flexible display panel  10 , and the second zipper chain  73  is disposed on a side edge of the flexible backplane  60 . 
     When simultaneously driving the flexible display panel  10  and the flexible backplane  60  to switch from the unrolled state to the rolled state, the driving unit  30  drives the first zipper chain  72  and the second zipper chain  73  to roll so as to move relative to the lock catch  71 , such that the lock catch  71  separates the first zipper chain  72  and the second zipper chain  73  in a fastened state. When simultaneously driving the flexible display panel  10  and the flexible backplane  60  to switch from the rolled state to the unrolled state, the driving unit  30  drives the first zipper chain  72  and the second zipper chain  73  in a rolled state to unroll so as to move relative to the lock catch  71 , such that the lock catch  71  fastens the first zipper chain  72  and the second zipper chain  73 . 
     In this way, when the flexible display panel  10  and the flexible backplane  60  are unrolled, the first zipper chain  72  and the second zipper chain  73  are fastened together to connect side edges of the flexible display panel  10  and the flexible backplane  60  on the same side. In this case, the flexible display device appears to be a complete structure, and a user may not see the auxiliary structure  20  through the side edges, which can improve the aesthetics of the flexible display device  100  and improve the user experience. When the flexible display panel  10  and the flexible backplane  60  are rolled, the first zipper chain  72  and the second zipper chain  73  are rolled and accommodated in the accommodating unit  40  without being exposed from the accommodating unit  40 . 
     [ 100 ] In an embodiment, the lock catch  71  may be fixedly provided on the inner wall of the second housing  42 . In this way, the lock catch  71  is fixed, while the first zipper chain  72  and the second zipper chain  73  move, and when the first zipper chain  72  and the second zipper chain  73  pass through the lock catch  71 , the lock catch  71  causes the first zipper chain  72  and the second zipper chain  73  to fasten together or separate from each other. 
     In an embodiment, referring to  FIG.  10   , the flexible display device further includes a chip on film (COF)  81 , a printed circuit board (PCB)  82  and a control circuit board  90 . One end of the chip on film  81  is electrically connected with the flexible display panel, the other end is electrically connected to one end of the printed circuit board  82 , and the other end of the printed circuit board  82  is electrically connected with the control circuit board  90 . The chip on film  81 , the printed circuit board  82  and the control circuit board  90  are accommodated in the accommodating unit  40 . 
     The flexible display device according to embodiments of the present application may include, for example, any device with a display function, such as mobile phone, tablet computer, TV set, notebook computer, and vehicle-mounted device. 
     It should be noted that, sizes of layers and regions may be exaggerated in the drawings for clarity of illustration. Also, it may be understood that when an element or layer is referred to as being “on” another element or layer, it may be directly on the other element or intervening layers may be present. In addition, it may be understood that when an element or layer is referred to as being “under” another element or layer, it may be directly under the other element, or more than one intervening layer or element may be present. In addition, it may be understood that when a layer or element is referred to as being “between” two layers or elements, it may be the only layer between the two layers or elements, or more than one intervening layer or element may be present. Like reference numerals indicate like elements throughout. 
     Other embodiments of the present application may readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure disclosed herein. The present application is intended to cover any modifications, uses, or adaptations thereof that follow the general principles of the present application and include common general knowledge or commonly used technical means in the art that are not disclosed in the present application. The specification and embodiments are to be considered exemplary only, with the true scope and spirit of the present application being indicated by the following claims. 
     It should be understood that the present application is not limited to the precise structures described above and illustrated in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.