Patent Publication Number: US-2022236767-A1

Title: Bendable display module and display device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese patent application No. 202111574628.9 filed with the China National Intellectual Property Administration (CNIPA) on Dec. 21, 2021, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD 
     Embodiments of the present disclosure relate to the field of display technology and, in particular, to a bendable display module and a display device. 
     BACKGROUND 
     With the increasing development of display technology, various display products with different characteristics emerge to satisfy different requirements of use. A flexible display device is such a new-type display product with flexibility. When in use, a user can bend the flexible display device as required to reduce the size of the display device and enhance the portability of the display device. The user can also flatten the display device to obtain a relatively large display screen. 
     However, an existing flexible display device only supports one bent state (either the inwardly-bent state or the outwardly-bent state) and the display region of the flexible display device can only switch between two kinds of display areas (inwardly-bent and unbent, or outwardly-bent and unbent), to limit use functions and failing to meet the ever-increasing user requirements. 
     SUMMARY 
     The present disclosure provides a bendable display module and a display device to achieve various bent states and enhance user experience. 
     Embodiments of the present disclosure provide a bendable display module. The bendable display module includes a display panel component. 
     The display panel component includes a flexible display panel, and a first surface and a second surface that are disposed opposite to each other. The first surface is the light-emitting surface of the flexible display panel. 
     The display panel component further includes a first bendable portion and a second bendable portion. 
     The bendable display module includes the inwardly-bent state, the unbent state, and the outwardly-bent state. 
     In the unbent state, the first bendable portion and the second bendable portion are flattened. 
     In the inwardly-bent state, the first bendable portion is bent in the direction of the first surface facing away from the second surface. 
     In the outwardly-bent state, the second bendable portion is bent in the direction of the second surface facing away from the first surface. 
     The area of the display region of the flexible display panel in the outwardly-bent state is larger than the area of the display region of the flexible display panel in the unbent state. 
     Embodiments of the present disclosure further provide a display device. The display device includes a bendable display module. The bendable display module includes a display panel component. The display panel component includes a flexible display panel, a first surface, a second surface, a first bendable portion and a second bendable portion. The first surface and the second surface are disposed opposite to each other, and the first surface is a light-emitting surface of the flexible display panel. The bendable display module includes the inwardly-bent state, the unbent state, and the outwardly-bent state. In the unbent state, the first bendable portion and the second bendable portion are flattened. In the inwardly-bent state, the first bendable portion is bent in the direction of the first surface facing away from the second surface. In the outwardly-bent state, the second bendable portion is bent in the direction of the second surface facing away from the first surface. The area of the display region of the flexible display panel in the outwardly-bent state is larger than the area of the display region of the flexible display panel in the unbent state. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a top view illustrating the structure of a bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 2  is a side view illustrating the structure of a bendable display module in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 3  is a side view illustrating the structure of a bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 4  is a side view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 5  is a diagram illustrating the structure of a bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 6  is a diagram illustrating the structure of another bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 7  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 8  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 9  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 10  is a partial enlarged view illustrating the structure of a display panel component in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 11  is a partial enlarged view illustrating the structure of a display panel component in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 12  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 13  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 14  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 15  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 16  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 17  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 18  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 19  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 20  is a diagram illustrating the structure of another bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 21  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 22  is a section view taken along the direction B-B′ of  FIG. 21 . 
         FIG. 23  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 24  is a section view taken along the direction C-C′ of  FIG. 23 . 
         FIG. 25  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 26  is a sectional diagram taken along the direction D-D′ of  FIG. 25 . 
         FIG. 27  is a partial section view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 28  is a partial section view illustrating the structure of a bendable display module in the unbent state and the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 29  is a partial section view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 30  is a partial section view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 31  is a partial top view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 32  is a partial view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 33  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure. 
         FIG. 34  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure. 
         FIG. 35  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. 
         FIG. 36  is a view illustrating the structure of a display device according to embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is further described hereinafter in detail in conjunction with drawings and embodiments. It is to be understood that embodiments described hereinafter are merely intended to explain the present disclosure and not to limit the present disclosure. Additionally, it is to be noted that for ease of description, only part, not all, of structures related to the present disclosure are illustrated in the drawings. 
       FIG. 1  is a top view illustrating the structure of a bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 2  is a side view illustrating the structure of a bendable display module in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 3  is a side view illustrating the structure of a bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 4  is a side view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 1 to 4 , a bendable display module provided in embodiments of the present disclosure includes a display panel component  10 . The display panel component  10  includes a flexible display panel  11 . The display panel component  10  further includes a first surface  12  and a second surface  13  that are disposed opposite to each other. The first surface  12  is the light-emitting surface of the flexible display panel  11 . The display panel component  10  further includes a first bendable portion  14  and a second bendable portion  15 . The bendable display module includes the inwardly-bent state, the unbent state, and the outwardly-bent state. In the unbent state, the first bendable portion  14  and the second bendable portion  15  are flattened. In the inwardly-bent state, the first bendable portion  14  is bent in the direction of the first surface  12  facing away from the second surface  13 . In the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 . The area of the display region of the flexible display panel  11  in the outwardly-bent state is larger than the area of the display region of the flexible display panel  11  in the unbent state. 
     The display panel component  10  may be bent and may be, for example, a flexible organic light-emitting diode (OLED) display screen, a liquid crystal display (LCD) display screen, or electronic paper. The display panel component  10  enables a bendable display device to change between the inwardly-bent state, the unbent state, and the outwardly-bent state. 
     As shown in  FIGS. 1 to 4 , the display panel component  10  includes the flexible display panel  11  to implement bending and display functions. The display panel component  10  includes the first surface  12  and the second surface  13  that are disposed opposite to each other. The first surface  12  is the light-emitting surface of the flexible display panel  11 . 
     The bendable display module includes the inwardly-bent state, the unbent state, and the outwardly-bent state to implement a 360° bending and enhance user experience. 
     Exemplarily, as shown in  FIG. 1  and  FIG. 3 , when the bendable display module is in the unbent state, the first bendable portion  14  of the display panel component  10  and the second bendable portion  15  of the display panel component  10  are flattened to obtain a relatively large display screen and meet the requirements of use for various scenarios and multiple tasks, including working and entertainment. 
     The arrangement in which the first bendable portion  14  and the second bendable portion  15  are flattened indicates that the light-emitting surface of the first bendable portion  14  is a plane, that the light-emitting surface of the second bendable portion  15  is a plane, and that the light-emitting surface of the first bendable portion  14  and the light-emitting surface of the second bendable portion  15  are located in the same plane. In the present application, a flattened arrangement indicates that a light-emitting surface is a plane, which is not repeated in the embodiments hereinafter. 
     With continued reference to  FIG. 2 , when the bendable display module is in the inwardly-bent state, the first bendable portion  14  is bent in the direction of the first surface  12  facing away from the second surface  13 , to enhance the portability of the bendable display module. In one embodiment, in this case, the light-emitting surface of the flexible display panel  11  faces inside, protecting the flexible display panel  11  and reducing the abrasion of the flexible display panel  11  in the non-use state. 
     With continued reference to  FIG. 4 , when the bendable display module is in the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 , achieving a small-screen display, making it convenient for a user to operate with one hand, and facilitating use. 
       FIG. 5  is a diagram illustrating the structure of a bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIG. 5 , exemplarily, when the bendable display module is in the unbent state, the display region of the flexible display panel  11  faces the user (in  FIG. 5 , the display region faces upward) and the user may watch an image displayed in the display region of the flexible display panel  11 . When the bendable display module is converted from the unbent state to the outwardly-bent state, the display region of the flexible display panel  11  faces the outside. Accordingly, even if the bendable display module is bent, the user can still watch the image displayed on the flexible display panel  11 . 
     Further, as shown in  FIG. 5 , the bendable display module further includes a middle frame  16 . The middle frame  16  is used for accommodating the display panel component  10 . The Inventor has found through research that when the bendable display module is in the unbent state, the area of the display region of the flexible display panel  11  is equal to the area of the accommodation region provided by the middle frame  16 . When the bendable display module is converted from the unbent state to the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 ; in this case, an additional display region is needed at the bend for display. Accordingly, if the light-emitting surface of the second bendable portion  15  of the flexible display panel  11  serves as the display region at the bend, the area of the display region of the flexible display panel  11  on the middle frame  16  is smaller than the area of the accommodation region provided by the middle frame  16 . In order to prevent the flexible display panel  11  from being damaged due to the straining and stretching of the flexible display panel  11 , in this case, part of the accommodation region (the region indicated by the elliptical dotted box in  FIG. 5 ) on the middle frame  16  may not be provided with the flexible display panel  11  for display. That is, a block of the display region is missing from the middle frame  16 , affecting the appearance and display effect of the bendable display module. 
       FIG. 6  is a diagram illustrating the structure of another bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIG. 6 , in this embodiment, the area of the display region of the flexible display panel  11  in the outwardly-bent state is arranged to be larger than the area of the display region of the flexible display panel  11  in the unbent state. With this arrangement, when the bendable display module is in the unbent state, part of the region of the flexible display panel  11  does not display and the area of the display region is equal to the area of the accommodation region provided by the middle frame  16 . When the bendable display module is converted from the unbent state to the outwardly-bent state, the display region of the flexible display panel  11  enlarges; the light-emitting surface of the second bendable portion  15  serves as the display region at the bend and the increased display region of the flexible display panel  11  is used for compensating for the missing display region on the middle frame  16 , to enhance the aesthetics of the bendable display module and improving the display effect of the bendable display module. 
     To sum up, for the bendable display module provided in embodiments of the present disclosure, in the unbent state, the first bendable portion  14  and the second bendable portion  15  are flattened; in the inwardly-bent state, the first bendable portion  14  is bent in the direction of the first surface  12  facing away from the second surface  13 ; and in the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 . This arrangement enables the bendable display module to be switched seamlessly between the inwardly-bent state, the unbent state, and the outwardly-bent state as well as enhances user experience. In one embodiment, the area of the display region of the flexible display panel  11  in the outwardly-bent state is arranged to be larger than the area of the display region of the flexible display panel  11  in the unbent state and when the bendable display module is converted from the unbent state to the outwardly-bent state, the area of the display region of the flexible display panel  11  is increased to compensate for the missing display region on the middle frame  16 , to enhance the aesthetics of the bendable display module and improving the display effect of the bendable display module. 
       FIG. 7  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 8  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 9  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure.  FIG. 10  is a partial enlarged view illustrating the structure of a display panel component in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 11  is a partial enlarged view illustrating the structure of a display panel component in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 5 to 9 , the bendable display module provided in embodiments of the present disclosure may further include a bent structure  17  used for driving the first bendable portion  14  and the second bendable portion  15  to deform. The bent structure  17  is located on a side of the second surface  13  facing away from the first surface  12 . As shown in  FIG. 10  and  FIG. 11 , in the inwardly-bent state, the bend radius of the first bendable portion  14  is R 1 ; and in the outwardly-bent state, the bend radius of the second bendable portion is R 2 . R 1 &lt;R 2 . 
     As shown in  FIGS. 5 to 9 , the bent structure  17  is disposed on the side of the second surface  13  of the display panel component  10  facing away from the first surface  12  to drive the first bendable portion  14  and the second bendable portion  15  to deform under the premise of not affecting the display of the flexible display panel  11 , thus enabling the bendable display module to be switched between the inwardly-bent state, the unbent state, and the outwardly-bent state. 
     The bent structure  17  may be a hinge or any other bent structure. Some embodiments may perform designing according to actual requirements, as long as the bendable display module can be switched between the inwardly-bent state, the unbent state, and the outwardly-bent state. This is not limited in embodiments of the present disclosure. 
     It is to be noted that the bent structure  17  in  FIGS. 5 to 9  is exemplified as a circle. In actual situations, the specific shape of the bent structure  17  is not limited to the circle. The bent structure  17  may also be in any other shape. For example, the bent structure  17  may be a wedge-shaped hinge or a U-shaped hinge. This is not limited in embodiments of the present disclosure. 
     Further, since the bent structure  17  on the side of the second surface  13  facing away from the first surface  12  has a thickness, the bend radius R 1  of the first bendable portion  14  in the inwardly-bent state is arranged to be smaller than the bend radius R 2  of the second bendable portion is R 2  in the outwardly-bent state to provide enough accommodation space for the bent structure  17  in the outwardly-bent state. 
     With continued reference to  FIGS. 1 to 11 , the display panel component  10  may further include a first non-bent portion  18  and a second non-bent portion  19 . In the unbent state, the first bendable portion  14  and the second bendable portion  15  are located between the first non-bent portion  18  and the second non-bent portion  19 . As shown in  FIGS. 1 to 4  and  FIGS. 6 to 9 , the display panel component  10  further includes a first compensation bendable portion  20 . The first compensation bendable portion  20  is located on a side of the second non-bent portion  19  facing away from the first bendable portion  14  and the second bendable portion  15 . In the unbent state and the inwardly-bent state, the first compensation bendable portion  20  is bent in the direction of the second surface  13  facing away from the first surface  12 . In the outwardly-bent state, the first compensation bendable portion  20  is flattened. 
     It is to be noted that the display panel component  10  shown in  FIG. 5  is only provided with the first non-bent portion  18  and the second non-bent portion  19  and is not provided with the first compensation bendable portion  20 . Therefore, when the bendable display module is converted from the unbent state to the outwardly-bent state, the light-emitting surface of the second bendable portion  15  serves as the display region at the bend. Part of the accommodation region (the region indicated by the elliptical dotted box in  FIG. 5 ) on the middle frame  16  may not be provided with the flexible display panel  11  for display. That is, a block of the display region is missing from the middle frame  16 , affecting the appearance and display effect of the bendable display module. 
     As shown in  FIGS. 1 to 4  and  FIGS. 7 to 9 , in this embodiment, the display panel component  10  is provided with the first non-bent portion  18 , the second non-bent portion  19 , and the first compensation bendable portion  20 . 
     As shown in  FIG. 3  and  FIG. 8 , in the unbent state, the first bendable portion  14  and the second bendable portion  15  are located between the first non-bent portion  18  and the second non-bent portion  19 . The first non-bent portion  18 , the second non-bent portion  19 , the first bendable portion  14 , and the second bendable portion  15  are flattened. In this case, the light-emitting surface of the first non-bent portion  18 , the light-emitting surface of the second non-bent portion  19 , the light-emitting surface of the first bendable portion  14 , and the light-emitting surface of the second bendable portion  15  are each a plane. In one embodiment, the light-emitting surface of the first non-bent portion  18 , the light-emitting surface of the second non-bent portion  19 , the light-emitting surface of the first bendable portion  14 , and the light-emitting surface of the second bendable portion  15  are located in the same plane for displaying an image. 
     With continued reference to  FIG. 3  and  FIG. 8 , in the unbent state, the first compensation bendable portion  20  is located on the side of the second non-bent portion  19  facing away from the first bendable portion  14  and the second bendable portion  15 . The first compensation bendable portion  20  is bent in the direction of the second surface  13  facing away from the first surface  12  to reduce the space occupied by the first compensation bendable portion  20  in the horizontal direction. In this case, the first compensation bendable portion  20  does not display. The area of the display region of the flexible display panel  11  is the sum of the area of the light-emitting surface of the first non-bent portion  18 , the area of the light-emitting surface of the second non-bent portion  19 , the area of the light-emitting surface of the first bendable portion  14 , and the area of the light-emitting surface of the second bendable portion  15  (it is to be noted that in the thickness direction of the flexible display panel  11 , if the first bendable portion  14  overlaps the second bendable portion  15 , the area of the light-emitting surface of the overlap needs to be subtracted). 
     As shown in  FIG. 2  and  FIG. 7 , in the inwardly-bent state, the first bendable portion  14  is bent in the direction of the first surface  12  facing away from the second surface  13 . In this case, the light-emitting surface of the first non-bent portion  18  and the light-emitting surface of the second non-bent portion  19  are opposite to each other, with no displaying. 
     With continued reference to  FIG. 2  and  FIG. 7 , in the inwardly-bent state, the first compensation bendable portion  20  may be bent in the direction of the second surface  13  facing away from the first surface  12 . In this case, the first compensation bendable portion  20  may serve as a secondary screen to display, for example, relatively simple information including date and weather and the user can obtain required information without unbending the bendable display module, to enhance user experience. 
     As shown in  FIG. 4  and  FIG. 9 , in the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 . In this case, the light-emitting surface of the first non-bent portion  18  and the light-emitting surface of the second non-bent portion  19  face outward and display an image. 
     With continued reference to  FIG. 4  and  FIG. 9 , in the outwardly-bent state, the first compensation bendable portion  20  may be flattened. In this case, the light-emitting surface of the first compensation bendable portion  20  is a plane. In one embodiment, the light-emitting surface of the first compensation bendable portion  20  and the light-emitting surface of the second non-bent portion  19  are located in the same plane. Accordingly, the first compensation bendable portion  20  serves as a part of the display region of the flexible display panel  11  for display. In this case, the area of the display region of the flexible display panel  11  is the sum of the area of the light-emitting surface of the first non-bent portion  18 , the area of the light-emitting surface of the second non-bent portion  19 , the area of the light-emitting surface of the first bendable portion  14 , the area of the light-emitting surface of the second bendable portion  15 , and the area of the light-emitting surface of the first compensation bendable portion  20  (it is to be noted that in the thickness direction of the flexible display panel  11 , if the first bendable portion  14  overlaps the second bendable portion  15 , the area of the light-emitting surface of the overlap needs to be subtracted). In the outwardly-bent state, the arrangement in which the first compensation bendable portion  20  is added for display compensates for the area of the display region required at the bend and fills the missing display region on the middle frame  16 , to enhance the aesthetics of the bendable display module and improving the display effect of the bendable display module. 
     It is to be noted that in the inwardly-bent state and the unbent state, the first compensation bendable portion  20  is not limited to being bent. In other embodiments, the first compensation bendable portion  20  may also be arranged in another shape in the inwardly-bent state and the unbent state. For example, as shown in  FIG. 7 , the first compensation bendable portion  20  may also be arranged to be flattened in the inwardly-bent state and the unbent state. In this case, the first compensation bendable portion  20  may be shielded by a structure such as a housing and the first compensation bendable portion  20  is hidden and does not display. This is not limited in embodiments of the present disclosure. 
       FIG. 12  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 13  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 14  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 15  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 12 to 15 , the display panel component  10  may further include a second compensation bendable portion  21 . The second compensation bendable portion  21  is located on a side of the first non-bent portion  18  facing away from the first bendable portion  14  and the second bendable portion  15 . In the unbent state and the inwardly-bent state, the second compensation bendable portion  21  is bent in the direction of the second surface  13  facing away from the first surface  12 . In the outwardly-bent state, the second compensation bendable portion  21  is flattened. 
     As shown in  FIG. 12  and  FIG. 14 , in the unbent state, the second compensation bendable portion  21  is located on a side of the first non-bent portion  18  facing away from the first bendable portion  14  and the second bendable portion  15 . The first compensation bendable portion  20  and the second compensation bendable portion  21  are bent in the direction of the second surface  13  facing away from the first surface  12  to reduce the space occupied by the first compensation bendable portion  20  in the horizontal direction. In this case, the first compensation bendable portion  20  and the second compensation bendable portion  21  do not display. The area of the display region of the flexible display panel  11  is the sum of the area of the light-emitting surface of the first non-bent portion  18 , the area of the light-emitting surface of the second non-bent portion  19 , the area of the light-emitting surface of the first bendable portion  14 , and the area of the light-emitting surface of the second bendable portion  15  (it is to be noted that in the thickness direction of the flexible display panel  11 , if the first bendable portion  14  overlaps the second bendable portion  15 , the area of the light-emitting surface of the overlap needs to be subtracted). 
     As shown in  FIG. 13 , in the inwardly-bent state, the first compensation bendable portion  20  and the second compensation bendable portion  21  are bent in the direction of the second surface  13  facing away from the first surface  12 . In this case, the first compensation bendable portion  20  and the second compensation bendable portion  21  may both serve as the secondary screen for display, for example, relatively simple information including date and weather and the user can obtain required information without unbending the bendable display module, to enhance user experience. 
     As shown in  FIG. 15 , in the outwardly-bent state, the first compensation bendable portion  20  and the second compensation bendable portion  21  are flattened. In this case, the light-emitting surface of the first compensation bendable portion  20  and the light-emitting surface of the second compensation bendable portion  21  are each a plane. In one embodiment, the light-emitting surface of the first compensation bendable portion  20  and the light-emitting surface of the second non-bent portion  19  are located in the same plane, and the light-emitting surface of the second compensation bendable portion  21  and the light-emitting surface of the first non-bent portion  18  are located in the same plane. Accordingly, the first compensation bendable portion  20  and the second compensation bendable portion  21  may serve as a part of the display region of the flexible display panel  11  for display. In this case, the area of the display region of the flexible display panel  11  is the sum of the area of the light-emitting surface of the first non-bent portion  18 , the area of the light-emitting surface of the second non-bent portion  19 , the area of the light-emitting surface of the first bendable portion  14 , the area of the light-emitting surface of the second bendable portion  15 , the area of the light-emitting surface of the first compensation bendable portion  20 , and the area of the light-emitting surface of the second compensation bendable portion  21  (it is to be noted that in the thickness direction of the flexible display panel  11 , if the first bendable portion  14  overlaps the second bendable portion  15 , the area of the light-emitting surface of the overlap needs to be subtracted). In the outwardly-bent state, the arrangement in which the first compensation bendable portion  20  and the second compensation bendable portion  21  are added to two opposite sides of the flexible display panel  11  for display compensates for the area of the display region required at the bend and fills the missing display region on the middle frame  16 , to enhance the aesthetics of the bendable display module and improving the display effect of the bendable display module. 
     It is to be noted that in the inwardly-bent state and the unbent state, the second compensation bendable portion  21  is not limited to being bent. In other embodiments, the second compensation bendable portion  21  may also be arranged in another shape in the inwardly-bent state and the unbent state. For example, the second compensation bendable portion  21  may also be arranged to be flattened in the inwardly-bent state and the unbent state. In this case, the second compensation bendable portion  21  may be shielded by a structure such as a housing and the second compensation bendable portion  21  is hidden and does not perform display. This is not limited in embodiments of the present disclosure. 
     With continued reference to  FIGS. 1, 3, 8, 12 and 14 , in the thickness direction of the display panel component  10 , the first bendable portion  14  and the second bendable portion  15  at least partially overlap with each other. 
     With the increase of bending times, the characteristics of transistors in the bent region of the flexible display panel  11  may change. Such change may cause the potential of a key node in the pixel circuit of the flexible display panel  11  to shift, leading to the problem, for example, a bright spot or not being dark in the dark state, in the bent region. It affects the display effect of the bent region. 
     In this embodiment, the arrangement in which the first bendable portion  14  and the second bendable portion  15  at least partially overlap with each other reduces the total area of the required bent region of the display panel component  10  in the outwardly-bent state and the inwardly-bent state, thus reducing the area of the display region affected by bending. 
     With continued reference to  FIGS. 1 to 4  and  FIGS. 12 to 15 , in the inwardly-bent state, the bend centerline of the first bendable portion  14  may be a first bend centerline  22 . In the outwardly-bent state, the bend centerline of the second bendable portion  15  may be a second bend centerline  23 . In the thickness direction of the display panel component  10 , the first bend centerline  22  and the second bend centerline  23  overlap with each other. 
     It is to be noted that any bend centerline in the present application refers to a straight line located inside a bent portion, passing through the geometric center of the bent portion, and extending in the direction perpendicular to the direction of the bent portion pointing to a non-bent portion. In the unbent state, the bent portion is symmetrical about the bend centerline. This is not repeated in the embodiments hereinafter. 
     Exemplarily, as shown in  FIGS. 1 to 4  and  FIGS. 12 to 15 , the bend centerline of the first bendable portion  14  is the first bend centerline  22 . In the unbent state, the first bendable portion  14  is symmetrical about the first bend centerline  22 . In the inwardly-bent state, both sides of the first bendable portion  14  facing away from the first bend centerline  22  have the same shortest straight-line distance from the first bend centerline  22 . The bend centerline of the second bendable portion  15  is the second bend centerline  23 . In the unbent state, the second bendable portion  15  is symmetrical about the second bend centerline  23 . In the outwardly-bent state, both sides of the second bendable portion  15  facing away from the second bend centerline  23  have the same shortest straight-line distance from the second bend centerline  23 . 
     In this embodiment, in the thickness direction of the display panel component  10 , the first bend centerline  22  and the second bend centerline  23  are arranged to overlap and the first bendable portion  14  and the second bendable portion  15  are each symmetrical about the first bend centerline  22  (the second bend centerline  23 ) in the unbent state, being conducive to reducing the difficulty of designing the bent structure  17  that drives the first bendable portion  14  and the second bendable portion  15  to deform, and thus facilitating implementation. 
       FIG. 16  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 17  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 18  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 19  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 16 to 19 , in the inwardly-bent state, the bend centerline of the first bendable portion  14  may be the first bend centerline  22 . In the outwardly-bent state, the bend centerline of the second bendable portion  15  may be the second bend centerline  23 . In the unbent state, in the direction parallel to the plane in which the first bendable portion  14  is located, the distance between the first bend centerline  22  and the second bend centerline  23  is A, where A&gt;0. 
     In the inwardly-bent state, the maximum stress is applied to the first bendable portion  14  at the first bend centerline  22 . In the outwardly-bent state, the maximum stress is applied to the second bendable portion  15  at the second bend centerline  23 . In this embodiment, the distance A between the first bend centerline  22  and the second bend centerline  23  is arranged to be larger than 0 and the first bend centerline  22  and the second bend centerline  23  are located in different positions of the display panel component  10 . Accordingly, the position where the maximum stress is applied to the display panel component  10  in the inwardly-bent state is different from the position where the maximum stress is applied to the display panel component  10  in the outwardly-bent state, being conducive to reducing the crease and preventing a fatigue break caused by the repeated inward and outward bending of the display panel component  10  at the same position. 
     With continued reference to  FIG. 16  and  FIG. 18 , A π*(R 2 −R 1 )/2. 
     Exemplarily, as shown in  FIG. 16  and  FIG. 18 , an example in which A π*(R 2 −R 1 )/2 is taken. In this case, in the unbent state, the projection of the second bendable portion  15  in the thickness direction of the display panel component  10  completely covers the projection of the first bendable portion  14  in the thickness direction of the display panel component  10 . In one embodiment, a boundary of the first bendable portion  14  is parallel to the first bend centerline  22  and overlaps a boundary of the second bendable portion  15  which is parallel to the second bend centerline  23 . 
     As shown in  FIG. 16  and  FIG. 18 , in this embodiment, the arrangement in which A π*(R 2 −R 1 )/2 ensures that the projection of the second bendable portion  15  in the thickness direction of the display panel component  10  completely covers the projection of the first bendable portion  14  in the thickness direction of the display panel component  10 ; In one embodiment, this arrangement ensures that the distance A between the first bend centerline  22  and the second bend centerline  23  is the longest. Accordingly, the area of the display region affected by bending is reduced and the distance between the first bend centerline  22  and the second bend centerline  23  is as long as possible, which is further conducive to reducing the crease and preventing a fatigue break caused by the repeated inward and outward bending of the display panel component  10  at the same position. 
     With continued reference to  FIGS. 1, 3, 12, 14, 16 and 18 , in the unbent state, the length of the first bendable portion  14  in a first direction X may be D 1 . The length of the second bendable portion  15  in the first direction X may be D 2 . D 1 =π*R 1 . D 2 =π*R 2 . The first direction is perpendicular to the extension direction of the first bend centerline  22 . In one embodiment, the first direction X is parallel to the plane in which the first bendable portion  14  in the unbent state is located. 
     The bend radius of the first bendable portion  14  is R 1 . The length D 1  of the first bendable portion  14  in the first direction X is arranged to be that D 1 =π*R 1  and the first bendable portion  14  can be bent by 180° when bent inwardly, enhancing the portability of the bendable display module. Meanwhile, the area of the first bendable portion  14  is not excessively large, reducing the area of the display region affected by bending. 
     Further, the bend radius of the second bendable portion  15  is R 2 . The length D 2  of the second bendable portion  14  in the first direction X is arranged to be that D 2 =π*R 2  and the second bendable portion  15  can be bent by 180° when bent outwardly, enhancing the portability of the bendable display module. Meanwhile, the area of the second bendable portion  15  is not excessively large, reducing the area of the display region affected by bending. 
       FIG. 20  is a diagram illustrating the structure of another bendable display module converted from the unbent state to the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 5, 6 and 20 , the bendable display module provided in embodiments of the present disclosure may further include a middle frame  16 . The middle frame  16  is used for accommodating the display panel component  10 . The first non-bent portion  18  is securely connected to the middle frame  16 . The second non-bent portion  19  is slidably connected to the middle frame  16 . 
     As shown in  FIGS. 5, 6 and 20 , the first non-bent portion  18  is securely connected to the middle frame  16 . When the bendable display module is in the unbent state, the area of the display region of the flexible display panel  11  is equal to the area of the accommodation region provided by the middle frame  16 . When the bendable display module is converted from the unbent state to the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 . An additional display region is needed at the bend for display. In this case, the light-emitting surface of the second bendable portion  15  of the flexible display panel  11  may serve as the display region at the bend. The second non-bent portion  19  is arranged to be slidably connected to the middle frame  16  and the second non-bent portion  19  on the middle frame  16  can slide in the direction toward the position where the second bendable portion  15  is located to cover the display region of the middle frame  16  that is originally covered by the second bendable portion  15 , to prevent the flexible display panel  11  from being damaged due to the straining and stretching of the flexible display panel  11 . When the bendable display module is converted from the outwardly-bent state to the unbent state, the second non-bent portion  19  on the middle frame  16  can slide in the direction away from the position where the second bendable portion  15  is located, making an accommodation space for the second bendable portion  15  at the bend portion, and to prevent the second bendable portion  15  from protruding and forming a fold. 
       FIG. 21  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 22  is a section view taken along the direction B-B′ of  FIG. 21 . As shown in  FIG. 21  and  FIG. 22 , the middle frame  16  may include a first guiding recess  24 . The second non-bent portion  19  is slidably disposed in the first guiding recess  24  and the second non-bent portion  19  moves in the extension direction of the first guiding recess  24 . The bend centerline of the first compensation bendable portion  20  during bending may be a third bend centerline  25 . The extension direction of the first guiding recess  24  is perpendicular to the extension direction of the third bend centerline  25 . The extension direction of the first guiding recess  24  is parallel to the plane in which the first compensation bendable portion  20  in the unbent state is located. 
     As mentioned above, when the bendable display module is converted from the unbent state to the outwardly-bent state or from the outwardly-bent state to the unbent state, the second non-bent portion  19  is displaced on the middle frame  16 . As shown in  FIG. 21  and  FIG. 22 , in this embodiment, the first guiding recess  24  is arranged on the middle frame  16  and the second non-bent portion  19  is slidably disposed in the first guiding recess  24  and the second non-bent portion  19  moves in the extension direction of the first guiding recess  24 , to prevent the second non-bent portion  19  from shifting and warping in the moving process, and guaranteeing the flatness of the second non-bent portion  19 . 
     It is to be noted that, as shown in  FIG. 22 , the edge of the middle frame  16  may be provided with a sidewall  161  and a protrusion portion  162  connected to the sidewall  161 . The protrusion portion  162  and the second non-bent portion  19  at least partially overlap each other and the first guiding recess  24  for accommodating part of the second non-bent portion  19  is formed on the middle frame  16 . The second non-bent portion  19  is embedded in the first guiding recess  24  to guide the second non-bent portion  19  to move in the extension direction of the first guiding recess  24 . In other embodiments, the first guiding recess  24  may also be formed on the middle frame  16  in other manners, which is not limited in embodiments of the present disclosure. 
       FIG. 23  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 24  is a section view taken along the direction C-C′ of  FIG. 23 . As shown in  FIG. 23  and  FIG. 24 , the display panel component  10  may further include a support structure  26 . The support structure  26  is located on a side of the flexible display panel  11  facing away from the light-emitting surface. The support structure  26  is securely connected to the flexible display panel  11 . In the extension direction of the third bend centerline  25 , the length of the support structure  26  is greater than the length of the flexible display panel  11 . In one embodiment, the edge of the support structure  26  protrudes from the edge of the flexible display panel  11 . 
     Exemplarily, as shown in  FIG. 23  and  FIG. 24 , the support structure  26  is arranged on the side of the flexible display panel  11  facing away from the light-emitting surface and is securely connected to the flexible display panel  11  to support the flexible display panel  11 . 
     As shown in  FIG. 23 , the length of the support structure  26  in the extension direction of the third bend centerline  25  is D 4 . The length of the flexible display panel  11  in the extension direction of the third bend centerline  25  is D 5 , where D 4 &gt;D 5 , and the edge of the support structure  26  protrudes from the edge of the flexible display panel  11 . In the extension direction of the third bend centerline  25 , the length of the support structure  26  is arranged to be greater than the length of the flexible display panel  11  and the edge of the support structure  26  is arranged to protrude from the edge of the flexible display panel  11  and the edge of the flexible display panel  11  is protected, preventing the edge of the flexible display panel  11  from being bumped when the flexible display panel  11  is moved or transferred. 
     The support structure  26  may be a support layer whose material and thickness are arranged according to actual requirements. For example, the support structure  26  is a stainless steel layer fully bonded to the flexible display panel  11 . This is not limited in embodiments of the present disclosure. 
     With continued reference to  FIG. 23  and  FIG. 24 , the part of the support structure  26  protruding from the flexible display panel  11  may be slidably disposed in the first guiding recess  24 . 
     Exemplarily, as shown in  FIG. 23  and  FIG. 24 , the part of the support structure  26  protruding from the flexible display panel  11  is slidably disposed in the first guiding recess  24 . When the bendable display module is converted from the unbent state to the outwardly-bent state or from the outwardly-bent state to the unbent state, the part of the support structure  26  protruding from the flexible display panel  11  may slide in the first guiding recess  24 . Since the flexible display panel  11  and the support structure  26  are secured, the flexible display panel  11  moves along with the support structure  26  and the support structure  26  drives the flexible display panel  11  to be displaced on the middle frame  16 , preventing the second non-bent portion  19  from shifting and warping in the moving process, guaranteeing the flatness of the second non-bent portion  19 , meanwhile, preventing the first guiding recess  24  from scratching the edge of the flexible display panel  11 , and helping increase the service life of the bendable display module. 
     With continued reference to  FIGS. 7 to 9 ,  FIG. 20 ,  FIG. 21 , and  FIG. 23 , the bendable display module provided in embodiments of the present disclosure may further include a sliding reel  27 . The sliding reel  27  is connected to the middle frame  16 . In the inwardly-bent state, the bend centerline of the first bendable portion  14  is the first bend centerline  22 . The axial direction of the sliding reel  27  is parallel to the extension direction of the first bend centerline  22 . In the unbent state and the inwardly-bent state, the first compensation bendable portion  20  is wound on the sliding reel  27 . 
     Exemplarily, as shown in  FIGS. 7 to 9 ,  FIG. 20 ,  FIG. 21 , and  FIG. 23 , in this embodiment, the sliding reel  27  is arranged to be connected to the middle frame  16 . The sliding reel  27  may be securely connected to the middle frame  16  or may be rotatably connected to the middle frame  16 . 
     With continued reference to  FIGS. 7 to 9 ,  FIG. 20 ,  FIG. 21 , and  FIG. 23 , when the bendable display module is in the unbent state and the inwardly-bent state, the first compensation bendable portion  20  is wound on the sliding reel  27  to enable the first compensation bendable portion  20  to be bent in the direction of the second surface  13  facing away from the first surface  12 , to reduce the space occupied by the first compensation bendable portion  20  in the direction perpendicular to the thickness direction of the flexible display panel  11 . 
     When the sliding reel  27  may be securely connected to the middle frame  16 , and the bendable display module is in the outwardly-bent state, the first compensation bendable portion  20  slides on the sliding reel  27  until sliding onto the middle frame  16  to be flattened, to compensate for the area of the display region required at the bend, filling the missing display region on the middle frame  16 , enhancing the aesthetics of the bendable display module, and improving the display effect of the bendable display module. 
     When the sliding reel  27  may be rotatably connected to the middle frame  16 , and the bendable display module is in the outwardly-bent state, the sliding reel  27  rotates to drive the first compensation bendable portion  20  to be displaced and then move onto the middle frame  16  to be flattened, to compensate for the area of the display region required at the bend, filling the missing display region on the middle frame  16 , enhancing the aesthetics of the bendable display module, and improving the display effect of the bendable display module. 
     In this embodiment, the sliding reel  27  is arranged at the position of the first compensation bendable portion  20  and the first compensation bendable portion  20  is wound on the sliding reel  27  in the unbent state and the inwardly-bent state, implementing the first compensation bendable portion  20  to be bent in the direction of the second surface  13  facing away from the first surface  12 . Accordingly, the first compensation bendable portion  20  is not suspended in the unbent state and the inwardly-bent state and it is unnecessary to arrange a support structure such as a hinge to support the first compensation bendable portion  20 , simplifying structural design and facilitating implementation. 
       FIG. 25  is a top view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 26  is a sectional diagram taken along the direction D-D′ of  FIG. 25 .  FIG. 27  is a partial section view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 25 to 27 , the middle frame  16  may include an arc-shaped guiding recess. In the outwardly-bent state, the bend centerline of the first bendable portion  14  is the first bend centerline  22 . In the direction parallel to the first bend centerline  22 , the arc-shaped guiding recess  28  is located on both sides of the first compensation bendable portion  20 . The protrusion direction Y of the arc-shaped guiding recess  28  faces away from the first bendable portion  14 . The first compensation bendable portion  20  is slidably disposed in the arc-shaped guiding recess  28  and the first compensation bendable portion  20  moves in the extension direction of the arc-shaped guiding recess  28 . 
     Exemplarily, as shown in  FIGS. 25 to 27 , in this embodiment, the middle frame  16  is provided with the arc-shaped guiding recess  28 . In the direction parallel to the first bend centerline  22 , the arc-shaped guiding recess  28  is located on both sides of the first compensation bendable portion  20  and the edges of both sides of the first compensation bendable portion  20  are placed in the arc-shaped guiding recess  28 . The protrusion direction Y of the arc-shaped guiding recess  28  faces away from the first bendable portion  14  to enable the first compensation bendable portion  20  to be bent in the direction of the second surface  13  facing away from the first surface  12 , to reduce the space occupied by the first compensation bendable portion  20  in the direction perpendicular to the thickness direction of the flexible display panel  11 . 
     The first compensation bendable portion  20  is slidably disposed in the arc-shaped guiding recess  28 . When the bendable display module is converted from the unbent state to the outwardly-bent state, the first compensation bendable portion  20  moves in the extension direction of the arc-shaped guiding recess  28  until sliding to the first guiding recess  24  to be flattened, to compensate for the area of the display region required at the outward bend, filling the missing display region on the middle frame  16 , enhancing the aesthetics of the bendable display module, and improving the display effect of the bendable display module. 
     In this embodiment, the middle frame  16  is provided with the arc-shaped guiding recess  28  and in the unbent state and the inwardly-bent state, the first compensation bendable portion  20  can be bent in the direction of the second surface  13  facing away from the first surface  12 . In one embodiment, the first compensation bendable portion  20  is not suspended in the unbent state and the inwardly-bent state and it is unnecessary to arrange a support structure such as a hinge to support the first compensation bendable portion  20 , simplifying structural design and facilitating implementation. 
       FIG. 28  is a partial section view illustrating the structure of a bendable display module in the unbent state and the inwardly-bent state according to embodiments of the present disclosure.  FIG. 29  is a partial section view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIG. 28  and  FIG. 29 , the bendable display module provided in embodiments of the present disclosure may further include an elastic structure  29 . The first compensation bendable portion  20  includes a free end  30 . When the first compensation bendable portion  20  is unbent, the free end  30  is located on a side of the first compensation bendable portion  20  facing away from the second non-bent portion  19 . The elastic structure  29  is connected to the middle frame  16  and the free end  30  separately. 
     Exemplarily, as shown in  FIG. 28  and  FIG. 29 , the middle frame  16  and the free end  30  of the first compensation bendable portion  20  are connected through the elastic structure  29  and in the inwardly-bent state and the unbent state, the elastic force of the elastic structure  29  is used for providing tension for the first compensation bendable portion  20 , to enable the first compensation bendable portion  20  to be bent in the direction of the second surface  13  facing away from the first surface  12 . Accordingly, when the bendable display module is converted from the unbent state to the outwardly-bent state, the first compensation bendable portion  20  is prevented from warping, being conducive to reducing the crease and further flattening the surface of the flexible display panel  11 . 
     The arrangement manner of the elastic structure  29  may be adopted according to actual requirements. For example, as shown in  FIG. 28  and  FIG. 29 , the elastic structure  29  includes an elastic element  291  and a fixed structure  292 . The elastic element  291  is connected to the middle frame  16  through the fixed structure  292 . However, it is not limited thereto. In other embodiments, the elastic structure  29  may only include an elastic element  291  directly connected to the middle frame  16 . 
     Further, the elastic element  291  is used for providing elastic force and may be manufactured by using any elastic material. For example, the elastic element  291  is made of a string or an elastic rope. This is not limited in embodiments of the present disclosure. 
     It is to be noted that the position for fixing the elastic structure  29  to the middle frame  16  may be arranged according to actual requirements. Exemplarily, as shown in  FIG. 28  and  FIG. 29 , the position for fixing the elastic structure  29  to the middle frame  16  is arranged below the second non-bent portion  19 . That is, in the thickness direction of the second non-bent portion  19 , the projection of the second non-bent portion  19  covers the projection of the position for fixing the elastic structure  29  to the middle frame  16 . 
       FIG. 30  is a partial section view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure.  FIG. 31  is a partial top view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIG. 30  and  FIG. 31 , the bendable display module provided in embodiments of the present disclosure may further include a moving shaft  31 . The free end  30  of the first compensation bendable portion  20  is connected to the moving shaft  31 . The elastic structure  29  is connected to both ends of the moving shaft  31 . 
     As shown in  FIG. 30  and  FIG. 31 , the free end  30  of the first compensation bendable portion  20  is connected to the moving shaft  31  and both ends of the moving shaft  31  are connected to the middle frame  16  through the elastic structure  29 , helping make the force on both ends of the moving shaft  31  even, thus preventing a fold from being generated on the flexible display panel  11 , and guaranteeing the flatness of the flexible display panel  11 . 
       FIG. 32  is a partial view illustrating the structure of a bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIG. 32 , the edge of the second non-bent portion  19  close to the first compensation bendable portion  20  may be a first edge  32 . When the first compensation bendable portion  20  is flattened, the edge of the first compensation bendable portion  20  facing away from the second non-bent portion  19  is a second edge  33 . The second edge  33  is parallel to the first edge  32 . 
     As shown in  FIG. 32 , the second edge  33  is arranged to be parallel to the first edge  32  and the display region of the flexible display panel  11  in the outwardly-bent state is well-shaped, to enhance the aesthetics of the bendable display module and improve the display effect of the bendable display module. 
     In one embodiment, the second edge  33  is arranged to be parallel to the first edge  32  and the elastic structure  29  can provide even tension for the free end  30  of the first compensation bendable portion  20 , to help reduce the possibility that a fold is generated on the flexible display panel  11  and guaranteeing the flatness of the flexible display panel  11 . 
     It is to be noted that the second edge  33  is not limited to being parallel to the first edge  32 . In other embodiments, the shape of the second edge  33  may also be set according to an actual desired display effect, which is not limited in embodiments of the present disclosure. 
     As shown in  FIG. 4  and  FIG. 19 , when the first compensation bendable portion  20  is flattened, the length of the first compensation bendable portion  20  in the first direction X may be D 3 , and D 3 =π*(R 2 −R 1 ). In the inwardly-bent state, the bend centerline of the first bendable portion  14  is the first bend centerline  22 . The first direction X is perpendicular to the extension direction of the first bend centerline  22 . In one embodiment, the first direction X is parallel to the plane in which the first bendable portion  14  in the unbent state is located. 
     As shown in  FIG. 2  and  FIG. 17 , when the bendable display module is in the inwardly-bent state, the first bendable portion  14  is bent in the direction of the first surface  12  facing away from the second surface  13 . In this case, the bend radius of the first bendable portion  14  is R 1 , and the flexible display panel  11  with a length of π*R 1  is required for display at the bend. As shown in  FIG. 4  and  FIG. 19 , when the bendable display module is in the outwardly-bent state, the second bendable portion  15  is bent in the direction of the second surface  13  facing away from the first surface  12 . In this case, the bend radius is R 2 , and the flexible display panel  11  with a length of π*R 2  is required for display at the bend. Accordingly, the difference between the length of the flexible display panel  11  required at the bend by the bendable display module in the inwardly-bent state and the length of the flexible display panel  11  required at the bend by the bendable display module in the outwardly-bent state is π*(R 2 −R 1 ). 
     In this embodiment, when the first compensation bendable portion  20  is flattened, the length D 3  of the first compensation bendable portion  20  in the first direction X is arranged to be that D 3 =π*(R 2 −R 1 ) and when the bendable display module is in the outwardly-bent state, the length of the first compensation bendable portion  20  exactly compensates for the difference between the length of the flexible display panel  11  required at the bend by the bendable display module in the inwardly-bent state and the length of the flexible display panel  11  required at the bend by the bendable display module in the outwardly-bent state. Accordingly, in the inwardly-bent state and the unbent state, the first compensation bendable portion  20  may not occupy too much space; In one embodiment, the cost of the bendable display module may be reduced. 
       FIG. 33  is a side view illustrating the structure of another bendable display module in the inwardly-bent state according to embodiments of the present disclosure.  FIG. 34  is a side view illustrating the structure of another bendable display module in the unbent state according to embodiments of the present disclosure.  FIG. 35  is a side view illustrating the structure of another bendable display module in the outwardly-bent state according to embodiments of the present disclosure. As shown in  FIGS. 28 to 29  and  FIGS. 33 to 35 , when the first compensation bendable portion  20  is flattened, the length of the first compensation bendable portion  20  in the first direction X may be D 3 , and D 3 &gt;π*(R 2 −R 1 ). In the inwardly-bent state, the bend centerline of the first bendable portion  14  is the first bend centerline  22 . The first direction X is perpendicular to the extension direction of the first bend centerline  22 . In one embodiment, the first direction X is parallel to the plane in which the first bendable portion  14  in the unbent state is located. 
     As shown in  FIGS. 28 to 29  and  FIGS. 33 to 35 , in this embodiment, when the first compensation bendable portion  20  is flattened, the length D 3  of the first compensation bendable portion  20  in the first direction X is arranged to be D 3 &gt;π*(R 2 −R 1 ) and when the bendable display module is in the inwardly-bent state, the first compensation bendable portion  20  may extend to the side of the second non-bent portion  19  facing away from the light-emitting surface of the second non-bent portion  19 . Accordingly, in the inwardly-bent state, the first compensation bendable portion  20  may display more information and a larger image and the user can watch a relatively large display screen without unbending the bendable display module, enhancing user experience. 
     It is to be noted that as shown in  FIGS. 28 to 29  and  FIGS. 33 to 35 , when the first compensation bendable portion  20  is flattened, the length D 3  of the first compensation bendable portion  20  in the first direction X refers to the sum of the length of the flattened part of the first compensation bendable portion  20  in the first direction X in the figures and the length of the bent part of the first compensation bendable portion  20 . 
     Exemplarily, as shown in  FIG. 34 , it is assumed that the length of the flattened portion of the first compensation bendable portion  20  in the first direction X is d 1 . The bend radius of the bent part of the first compensation bendable portion  20  is r 1 . Then when the first compensation bendable portion  20  is flattened, the length D 3  of the first compensation bendable portion  20  in the first direction X is equal to d 1 +(π*r 1 ). 
     With continued reference to  FIGS. 28 to 29  and  FIGS. 33 to 35 , when the first compensation bendable portion  20  is flattened and the length D 3  of the first compensation bendable portion  20  in the first direction X is greater than π*(R 2 −R 1 ), in the inwardly-bent state and the unbent state, only part of the first compensation bendable portion  20  may be arranged to be bent in the direction of the second surface  13  facing away from the first surface  12 . Part of the first compensation bendable portion  20  is flattened on a side of the second non-bent portion  19  facing away from the light-emitting surface of the second non-bent portion  19 . In one embodiment, the light-emitting surface of the first compensation bendable portion  20  is located on a side of the first compensation bendable portion  20  facing away from the second non-bent portion  19  to improve the display effect. In the outwardly-bent state, only part of the first compensation bendable portion  20  is flattened to compensate for the display region required at the bend. Part of the first compensation bendable portion  20  is bent in the direction of the second surface  13  facing away from the first surface  12 , enabling information to be displayed on a side and enhancing user experience. 
     Based on the same concept, embodiments of the present disclosure also provide a display device.  FIG. 36  is a view illustrating the structure of a display device according to embodiments of the present disclosure. As shown in  FIG. 36 , the display device  34  includes the bendable display module  35  described in any embodiment of the present disclosure. Accordingly, the display device  34  provided in embodiments of the present disclosure in the preceding embodiments. The explanations of the structures and terms that are the same as or corresponding to those in the preceding embodiments are not repeated here. 
     The display device  34  provided in embodiments of the present disclosure may be the phone shown in  FIG. 36 , or may be any electronic product with a display function, including but not limited to a television, a laptop, a desktop display, a tablet computer, a digital camera, a smart bracelet, a smart glass, a vehicle-mounted display, medical equipment, industrial control equipment, and a touch interactive terminal.