Patent Publication Number: US-2023164931-A1

Title: Flexible display panel and display device

Description:
TECHNICAL FIELD 
     The present invention relates to a technical field of display, in particular to a flexible display panel and a display device. 
     BACKGROUND 
     With gradual maturity of flexible organic light-emitting diode (OLED) display technology, the display industry is developing in a direction of lighter, thinner, and larger. In recent years, folding OLED display technology has been widely used in mobile phone and tablet computer industries. However, a crease problem of a folding display device has not been properly solved so far. In order to enable a screen of the display device to have a display effect in which a size of the screen can be freely switched and to minimize the crease problem, a crimpable and stretchable OLED technology has emerged. 
     A key point of the crimpable and stretchable OLED display technology is that a flexible display panel needs to bear a stretching and crimping force of a crimping mechanism in a process of unfolding and retracting. This requires that a flexible display panel not only can adapt well to this stress environment, but also avoid a problem of a peeling of an adhesive layer and film layer inside a module. At the same time, it also requires the flexible display panel to have good flatness after unfolding. 
     TECHNICAL PROBLEMS 
     A support plate made of stainless steel is generally provided at a bottom of a flexible display panel for supporting the flexible display panel in order to accommodate a bending performance and a flatness of the flexible display panel. In order to ensure that the flexible display panel has a good bending and crimping performance, the support plate is often designed to be very thin. However, the less a bending and crimping radius of the flexible display panel is, the thinner a thickness of a selected support plate is. However, the thinner the thickness of the support plate, the worse the rigidity. After the flexible display panel is unfolded, the flatness cannot meet a requirement for use. 
     As described above, a conventional flexible display panel and a stretchable display device have problems in that the flexible display panel cannot balance crimpiness and flatness. Therefore, it is necessary to provide a flexible display panel and a display device to improve this defect. 
     SUMMARY 
     An embodiment of the present application provides a flexible display panel and a display device, which are used to solve a problem that a conventional support plate and a display device cannot balance crimpiness and flatness of the flexible display panel. 
     An embodiment of the present application provides a flexible display panel including a flexible display panel body, and a support plate disposed at a bottom of the flexible display panel body, wherein the flexible display panel body has a flexible portion, the support plate has a crimping portion corresponding to the flexible portion, the crimping portion is provided with a plurality of grooves extending along a first direction and spaced along a second direction, the first direction is different from the second direction; 
     wherein a bottom of each of the grooves is provided with a plurality of first patterned structures. 
     According to an embodiment of the present application, each of the first patterned structures extends through the support plate along a third direction perpendicular to the first direction and the second direction. 
     According to an embodiment of the present application, the first patterned structure extends along the first direction; 
     in the first direction, at least two of the first patterned structures are disposed side by side at a bottom of a same groove; 
     in the second direction, any two of the first patterned structures adjacent to each other are staggeredly arranged at the bottom of the same groove. 
     According to an embodiment of the present application, the first patterned structure comprises an intermediate patterned structure and an edge patterned structure, and the edge patterned structure extends from an edge of the crimping portion perpendicular to the first direction toward an intermediate of the crimping portion; 
     wherein, in the first direction, the edge patterned structure is disposed side by side with the intermediate patterned structure; 
     in the second direction, at least one intermediate patterned structure is disposed between any two of the edge patterned structures adjacent to each other, the edge patterned structure is staggered with the intermediate patterned structure adjacent to the edge patterned structure. 
     According to an embodiment of the present application, a cross-sectional profile of the intermediate patterned structure is elongated, and a cross-sectional profile of the edge patterned structure is U-shaped. 
     According to an embodiment of the present application, in the second direction, a distance between any of the grooves adjacent to each other is less than a width of the groove. 
     According to an embodiment of the present application, a ratio of the distance between any of the grooves adjacent to each other to the width of the groove is greater than or equal to 0.2 and less than or equal to 0.5. 
     According to an embodiment of the present application, in the second direction, a distance between any of the first patterned structures adjacent to each other is less than a width of the first patterned structure. 
     According to an embodiment of the present application, in the second direction, a ratio of the distance between of the first patterned structures adjacent to each other to the width of the first patterned structure is greater than or equal to 0.4 and less than or equal to 0.6. 
     According to an embodiment of the present application, a ratio of a distance between the bottom of the groove and a bottom of the support plate to a thickness of the support plate is greater than ⅓ or equal to and less than or equal to ½. 
     According to an embodiment of the present application, the support plate further comprises a transition portion connected to the crimping portion, the transition portion is provided with a plurality of second patterned structures. 
     According to an embodiment of the present application, each of the second patterned structures penetrates the support plate in the third direction. 
     According to an embodiment of the present application, each of the second patterned structures extends along the first direction; 
     in the first direction, at least two of the second patterned structures are disposed side by side; 
     in the second direction, any two of the second patterned structures adjacent to each other are disposed side by side. 
     According to an embodiment of the present application, a density of the second patterned structure is less than a density of the first patterned structure. 
     According to an embodiment of the present application, a length of the second patterned structure in the first direction is less than a length of the first patterned structure in the first direction. 
     According to an embodiment of the present application, in the second direction, a distance between any of the second patterned structures adjacent to each other is greater than a distance between any of the first patterned structures adjacent to each other. 
     According to an embodiment of the present application, a ratio of the distance between any of the second patterned structures adjacent to each other to the distance between any of the first patterned structures adjacent to each other is greater than or equal to 1.2 and less than or equal to 2. 
     According to an embodiment of the present application, a density of the second patterned structure is less than a density of the first patterned structure. 
     An embodiment of the present application further provides a display device including a flexible display panel, wherein the flexible display panel comprises a flexible display panel body, and a support plate disposed at a bottom of the flexible display panel body, the flexible display panel body has a flexible portion, the support plate has a crimping portion corresponding to the flexible portion, the crimping portion is provided with a plurality of grooves extending along a first direction and spaced along a second direction, the first direction is different from the second direction; 
     wherein a bottom of each of the grooves is provided with a plurality of first patterned structures. 
     According to an embodiment of the present application, each of the first patterned structures extends through the support plate in a third direction perpendicular to the first direction and the second direction. 
     According to an embodiment of the present application, the first patterned structure extends along the first direction; 
     in the first direction, at least two of the first patterned structures are disposed side by side at a bottom of a same groove; 
     in the second direction, any two of the first patterned structures adjacent to each other are staggeredly arranged at the bottom of the same groove. 
     BENEFICIAL EFFECTS 
     An embodiment of the present disclosure provides a flexible display panel and a display device, the display device including a flexible display panel, the flexible display panel including a flexible display panel body and a support plate, the support plate being disposed at a bottom of the flexible display panel body, the flexible display panel being provided with a flexible portion, the support plate being provided with a crimping portion corresponding to the flexible portion, a plurality of grooves extending along a first direction and spaced along a second direction are provided at the crimping portion, and a plurality of first patterned structures are provided at a bottom of the groove, so that a bending performance of the crimping portion can be improved while a rigidity of the crimping portion is ensured, thereby balancing crimpiness and flatness of the flexible display panel in the display device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly illustrate the embodiments or prior art solutions, the accompanying drawings required for use in the description of the embodiments or prior art will be briefly described below. It will be apparent that the accompanying drawings in the following description are merely some of the disclosed embodiments, and other drawings may be obtained from these drawings without creative effort by one of ordinary skill in the art. 
         FIG.  1    is an exploded schematic diagram of a flexible display panel provided in an embodiment of the present application. 
         FIG.  2    is a structural schematic diagram of a support plate provided in an embodiment of the present application. 
         FIG.  3    is a structural schematic diagram of a flexible display panel in a bending state provided in an embodiment of the present application. 
         FIG.  4    is a cross-sectional view of the support plate along an A-A direction provided in an embodiment of the present application. 
         FIG.  5    is a schematic structural diagram of an edge portion of the support plate provided in an embodiment of the present application. 
         FIG.  6    is a partially enlarged schematic diagram of the edge portion of the support plate provided in an embodiment of the present application. 
         FIG.  7    is a principle diagram of a deformation of a crimping portion provided in an embodiment of the present application. 
         FIG.  8    is a plan schematic diagram of a deforming unit provided in an embodiment of the present application. 
         FIG.  9    is a relational graph of a length of a first patterned structure as a function of a bending stress and rebounding force. 
         FIG.  10    is a relational graph of a width of an intermediate patterned structure in a second direction x as a function of a bending stress and rebounding force. 
         FIG.  11    is a relational graph of a distance between adjacent first patterned structures as a function of a bending stress and rebounding force provided in an embodiment of the present application. 
         FIG.  12    is a structural schematic diagram of a display device in a retracted state provided in an embodiment of the present application. 
         FIG.  13    is a structural schematic diagram of a display device in an unfolded state provided in an embodiment of the present application. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The following embodiments are described with reference to additional illustrations to illustrate specific embodiments that may be implemented by the present disclosure. The direction terms mentioned in the present disclosure, such as [upper], [lower], [front], [rear], [left], [right], [inner], [outer], [side], and the like, refer only to the directions of the additional drawings. Therefore, a direction term is used to explain and understand the present disclosure, and not to limit the present disclosure. In the figure, elements of similar structure are denoted by the same reference numerals. 
     The disclosure will be further described with reference to the accompanying drawings and specific embodiments: 
     The present embodiment provides a flexible display panel. As shown in  FIG.  1   , the flexible display panel  100  includes a flexible display panel body  10  and a support plate  20 , and the support plate  20  may be disposed at a bottom of the flexible display panel body  10 . 
     In an embodiment of the present application, the support plate  20  and the flexible display panel body  10  may be bonded by a foam tape  30 . The foam tape  30  not only can provide good adhesive force, but also absorb a bending stress caused by a deformation of the support plate  20  during a bending process, thereby avoiding peeling between the support plate  20  and the flexible display panel body  10 , thus reducing a risk of peeling and fracture failure in the flexible display panel  100 . 
     The flexible display panel body  10  may include a back plate  11 , a display layer  12 , a polarizer  13 , and a protective plate  14  that are sequentially laminated, and the display layer  12  may include a driving circuit layer and a plurality of light-emitting components disposed on the driving circuit layer in an array and electrically connected to the driving circuit layer. 
     In an embodiment of the present application, the light-emitting device in the display layer  12  may be an organic light-emitting diode. In practical use, a type of light-emitting device in the display layer  12  is not limited to an organic light-emitting diode, but may be a mini light-emitting diode (mini LED) or a smaller micro light-emitting diode (Micro LED). 
     The polarizer  13  is a polymer optical film having high polarization optical characteristics, high temperature resistance, high humidity resistance, and the like. 
     The protective plate  14  may be made of a transparent polymer material so that the protective layer has excellent optical characteristics and wear-and-scratch resistance, and functions as a protective display layer  12 . 
     A material of the support plate  20  is stainless steel (SUS), so that the support plate  20  has a good rigidity and bending performance. Specifically, the support plate  20  may be a high-strength thin steel plate containing manganese, and nickel plated, with a single yield limit of no less than 1600 MPa, and is prepared through a cold-drawing process, and has excellent toughness and strength. In practical use, the material of the support plate  20  may include, but is not limited to, alloy materials such as titanium alloy, copper alloy, magnesium-aluminum alloy, or other metal materials, and may also be non-metallic materials such as carbon fiber composite plate. 
     As shown in  FIG.  2   ,  FIG.  2    is a structural schematic diagram of a support plate provided in an embodiment of the present application. The support plate  20  includes a crimping portion  201  and a non-crimping portion  202 . When the support plate  20  is in the unfolded state, the non-crimping portion  202  is provided on at least one side of the crimping portion  201 . The crimping portion  201  is provided with a plurality of grooves  21  extending along a first direction y and spaced along a second direction x, and the first direction y is different from the second direction x. By providing a plurality of spaced grooves  21  in the crimping portion  201  of the support plate  20 , overall rigidity of the crimping portion  201  can be reduced to improve the bending performance of the support plate  20 . 
     In an embodiment of the present application, the first direction y is perpendicular to the second direction x, the first direction y is parallel to a width direction of the support plate, and the second direction x is parallel to a length direction of the support plate. In practical use, the first direction y and the second direction x may also cross each other, but not perpendicularly. 
     As shown in  FIG.  3   ,  FIG.  3    is a structural schematic diagram of a flexible display panel in a bending state provided in an embodiment of the present application. The flexible display panel body  10  has a planar portion  101 , and a flexible portion  102  connected to the planar portion  101 , and the crimping portion  201  corresponding to the flexible portion  102  and serves to support the flexible portion  102 . 
     The flexible portion  102  has a good bending and folding performance. When the flexible portion  102  of the flexible display panel body  10  is bent, the back plate  11 , the display layer  12 , the polarizer  13 , the protective plate  14  corresponding to a portion where the flexible portion  102  is bent are also in a bending state, and the support plate  20  corresponding to a portion where the flexible portion  102  is bent are also in the bending state. When the flexible portion  102  does not bend, the back plate  11 , the display layer  12 , the polarizer  13  and the protective plate  14  corresponding to a portion where the flexible portion  102  does not bend are in an unfolded state, and the crimping portion  201  corresponding to the portion where the flexible portion  102  does not bend is also in an unfolded state. 
     In an embodiment of the present application, an opening of the groove  21  is provided on a side away from the flexible display panel body  10  toward the support plate  20 . It will be understood that at least a portion of the crimping portion  201  may be in a same plane with the non-crimping portion  202  when the flexible display panel body  10  is in the unfolded state, and that the function of supporting the flexible display panel body  10  is implemented together with the non-crimping portion  202 . By providing the opening of the groove  21  on a side away from the flexible display panel body  10  toward the support plate  20 , it is possible to avoid grooving the support plate  20  on a side facing the flexible display panel body  10  so that a surface of the support plate  20  on the side facing the flexible display panel body  10  becomes a flat surface, thereby ensuring a flatness of the flexible display panel body  10  in the unfolded state. 
     In an embodiment of the present application, a width of each of the grooves  21  in the second direction x is same, and a spacing distance between adjacent grooves  21  is also same, so that not only the manufacturing difficulty of the support plate  20  can be reduced, but also a curvature of each portion of the crimping portion  201  can be made uniform when the crimping portion  201  is in the bending state, so that the force applied to each portion of the crimping portion  201  can be more uniform. 
     In practical use, the width of the groove  21  may be gradually increased from an edge of the crimping portion  201  near the non-crimping portion  202  toward a center of the crimping portion  201 . The greater the width of the groove  21 , the smaller the rigidity of the crimping portion  201 , so that the bending performance of the crimping portion  201  can be gradually increased in the direction from the edge of the crimping portion  201  near the non-crimping portion  202  toward the center of the crimping portion  201 . Alternatively, the width of the groove  21  may be gradually decreased from the edge of the crimping portion  201  near the non-crimping portion  202  toward the center of the crimping portion  201 . 
     Further, a bottom of the groove  21  is provided with a plurality of first patterned structures  22 . 
     In an embodiment of the present application, as shown in  FIG.  2   , a plurality of first patterned structures  22  are provided at a bottom of each of the grooves  21 , and the number and density of the first patterned structures  22  in the bottom of each of the grooves  21  are same. 
     In practical use, the number or density of the first patterned structures  22  in the bottom of each of the grooves  21  may also be different. The more or the denser the first patterned structures  22  in the bottom of the grooves  21 , the smaller the bending rigidity of the crimping portion  201 , and the better the bending performance of the crimping portion  201 . For example, the number or density of the first patterned structure  22  in the bottom of the groove  21  may gradually increase or reduced from the edge of the crimping portion  201  near the non-crimping portion  202  toward the center of the crimping portion  201 . 
     In an embodiment of the present application, as shown in  FIG.  4   , which is a cross-sectional view of the support plate provided in the embodiment of the present application along an A-A direction, the first patterned structure  22  extends through the support plate  20  in a third direction z perpendicular to the first direction y and the second direction x. In this way, the bending rigidity of the crimping portion  201  can be further reduced, and the bending performance of the support plate  20  can be improved. The portion between the adjacent grooves  21  can serve as a support spoke  23  to maintain the rigidity of the support plate  20 , thereby ensuring the flatness of the display panel body  10  in the unfolded state. 
     Further, in the third direction z, a distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  should be less than or equal to half of a thickness H2 of the support plate  20 . The sum of a depth of the groove  21  and the distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  is the thickness H2 of the support plate  20 . The greater the depth of the groove  21  is, the better the bending performance of the crimping portion  201  is, and the smaller the bending rigidity is. In this way, it can be avoided that the bending performance of the crimping portion  201  cannot meet the demand of the flexible display panel due to the insufficient depth of the groove  21 . 
     Further, a ratio of the distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  to the thickness H2 of the support plate should be greater than or equal to ⅓ and less than or equal to ½, thereby balancing the rigidity and the bending performance of the support plate  20  at the crimping portion  201 . 
     In an embodiment of the present application, the ratio of the distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  to the thickness H2 of the support plate  20  is ½, the distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  is 100 μm, and the thickness H2 of the support plate  20  is 200 μm. In practical use, the thickness H2 of the support plate is not limited to the above-mentioned 200 μm but may be greater than or less than 200 μm. When the thickness of the support plate  20  is thin, the ratio of the distance H1 between the bottom of the groove  21  and the bottom of the support plate  20  to the thickness H2 of the support plate  20  may also be ⅓ or ⅖. 
     In other embodiments, in the third direction z, the first patterned structure  22  may also extend only from the bottom of the groove  21  to the inside of the support plate  20 , but not cross the support plate  20 . In this way, the rigidity of the crimping portion  201  can be further reduced to some extent and the bending performance of the support plate  20  can be improved. 
     Further, as shown in  FIGS.  5  and  6   ,  FIG.  5    is a structural schematic diagram of an edge portion of a support plate provided in an embodiment of the present application.  FIG.  6    is a partially enlarged schematic diagram of an edge portion of a support plate provided in an embodiment of the present application. The first patterned structure  22  extends along the first direction y. In the first direction y, at least two of the first patterned structures  22  are disposed side by side at a bottom of a same groove  21 , In the second direction x, any two adjacent first patterned structures  22  are staggered at the bottom of the same groove  21 . 
     In an embodiment of the present application, as shown in  FIG.  6   , a plurality of first patterned structures  22  are spaced and disposed side by side in the first direction y to form a row of first patterned structures  22 , and three rows of first patterned structures  22  are provided in each groove  21 . In the second direction x, any two adjacent first patterned structures  22  of any two adjacent rows of first patterned structures  22  are staggered. 
     In practical use, the number of rows of the first patterned structure provided in each of the grooves  21  may be selected according to the width of the grooves  21  and the bending performance required by the crimping portion  201  of the support plate  20 , and may be not limited to three rows in the above-described embodiment, but may be two, four, five or more rows. 
     In other embodiments, a plurality of first patterned structures  22  are disposed side by side in a first direction y to form a row of first patterned structures  22 , three rows of first patterned structures  22  are disposed within each groove  21 . In the second direction x, any two adjacent first patterned structures  22  of any two adjacent rows of first patterned structures  22  are disposed side by side. 
     Further, as shown in  FIG.  5   , the first patterned structure  22  includes an intermediate patterned structure  221  and an edge patterned structure  222 , and the edge patterned structure  222  extends from an edge of the crimping portion  201  perpendicular to the first direction y toward an intermediate of the crimping portion  201 . 
     Combined  FIG.  5    with  FIG.  6   , in the first direction y, the edge patterned structure  222  is disposed side by side with the intermediate patterned structure  221 , and in the second direction x, at least one intermediate patterned structure  221  is disposed between any adjacent edge patterned structures  222 , and the edge patterned structure  222  is staggered with the adjacent intermediate patterned structures  221 . By providing a plurality of edge patterned structures  222  at the edge of the crimping portion  201  perpendicular to the first direction y, the deformation and the stress caused at the intermediate portion of the crimping portion  201  are dispersed to the edge portion of the crimping portion  201 , thereby avoiding the stress of the intermediate portion and the edge portion of the crimping portion  201  from being excessively concentrated, and thus reducing the stress applied by the support plate  20  to the adjacent adhesive layer or film layer during the bending or crimping process. 
     In an embodiment of the present application, a length of the intermediate patterned structure  221  in the first direction y is greater than a length of the edge patterned structure in the first direction y. In practical use, the length of the intermediate patterned structure  221  in the first direction y may also be less than or equal to the length of the edge patterned structure  222  in the first direction y, which is not limited here. 
     Further, a cross-sectional profile of the intermediate patterned structure  221  is elongated, and a cross-sectional profile of the edge patterned structure  222  is U-shaped. 
     As shown in  FIG.  7   ,  FIG.  7    is a principle diagram of a deformation of a crimping portion provided in an embodiment of the present application. The cross-sectional profile of the intermediate patterned structure  221  paralleled to the first direction y and the second direction x has a first end portion  221   a , a second end portion  221   b , and a first connecting portion  221   c  and a second connecting portion  221   d  oppositely disposed. The first connecting portion  221   c  is connected to a side of the first end portion  221   a  and the second end portion  221   b , and the second connecting portion  221   d  is connected to another side of the first end portion  221   a  and the second end portion  221   b.    
     In one embodiment, the cross-sectional profiles of the first end portion  221   a  and the second end portion  221   b  are semicircular, and the cross-sectional profiles of the first connecting portion  221   c  and the second connecting portion  221   d  are linear. 
     In practical use, the cross-sectional profiles of the first end portion  221   a  and the second end portion  221   b  are not limited to be semicircular in the above-described embodiment, but may be semi-elliptical, curved-shaped having at least two bending portions with different bending directions, or other irregular shapes. The cross-sectional profiles of the first connecting portion  221   c  and the second connecting portion  221   d  are not limited to be semicircular in the above-described embodiment, but may be arcuate, curved-shaped having at least two bending portions with different bending direction, or other irregular patterns. 
     As shown in  FIG.  7   , The cross-sectional profile of the edge patterned structure  222  paralleled to the first direction y and the second direction x has a third end portion  222   a , and a third connecting portion  222   b  and a fourth connecting portion  222   c  oppositely disposed. The third connecting portion  222   b  and the fourth connecting portion  222   c  are connected to the third end portion  222   a , respectively. 
     In one embodiment, the cross-sectional profile of the third end portion  222   a  is semicircular, and the cross-sectional profiles of the third connecting portion  222   b  and the fourth connecting portion  222   c  are linear. 
     In practical use, the cross-sectional profiles of the third end portion  222   a  is not limited to be semicircular in the above-described embodiment, but may be semi-elliptical, curved-shaped having at least two bending portions with different bending directions, or other irregular shapes. The cross-sectional profiles of the third connecting portion  222   b  and the fourth connecting portion  222   c  are not limited to be semicircular in the above-described embodiment, but may be arcuate, curved-shaped having at least two bending portions with different bending direction, or other irregular patterns. 
     As shown in  FIG.  7   ,  FIG.  7    only illustrates one groove  21  and a plurality of rows of first patterned structures  22  located in the groove  21 . The first patterned structure  22  includes a first sub-patterned structure  22   a , a second sub-patterned structure  22   b , a third sub-patterned structure  22   c , and a fourth sub-patterned structure  22   d . A deforming unit  210  is formed by the first sub-patterned structure  22   a  in an n-th row of sub-patterned structures, the third sub-patterned structure  22   c  and the fourth sub-patterned structure  22   d  in an n+1-th row of sub-patterned structures, and the second sub-patterned structure  22   b  in an n+2-th row of sub-patterned structures. The second sub-patterned structure  22   b  is disposed side by side with the first sub-patterned structure  22   a , the third sub-patterned structure  22   c  and the fourth patterned structure  22   d  are disposed adjacent to the first sub-patterned structure  22   a . The third sub-patterned structure  22   c  includes the first end portion, a portion of the first connecting portion, and a portion of the second connecting portion. The fourth sub-patterned structure  22   d  includes the second end portion, a portion of the first connecting portion, and a portion of the second connecting portion. The deformation unit  210  has an H-shaped structure, wherein n is a positive integer greater than or equal to 1. A deformation unit  210  is shown in the dotted line box of  FIG.  7   . 
     In the process of returning the display device from the unfolded state to the retracted state, the crimping portion  201  may be bent from the unfolded state to the bending state along a direction indicated by the arrow. With an applied external tension, a portion of the first sub-patterned structure  22   a , the second sub-patterned structure  22   b , a portion of the third sub-patterned structure  22   c , and a portion of the fourth sub-patterned structure  22   d  are gradually deformed and unfolded along the direction indicated by the arrow, that is, a portion of the first sub-patterned structure  22   a , the second sub-patterned structure  22   b , a portion of the third sub-patterned structure  22   c , and a portion of the fourth sub-patterned structure  22   d  are gradually increased in the second direction x, so that the width of the groove  21  shown in the second direction x in  FIG.  9    is increased. An accumulation of deform-to-unfold actions of each deformation unit  210  in the crimping portion  201  during the bending or crimping process provides the crimping portion  201  with a better deformation performance, which helps to release the stress generated during the bending or crimping process. Thus, it ensures that the foam tape  30  attached to the flexible display panel body  10  can maintain an excellent deformation-following property with the support plate  20 , so that the crimping portion  201  of the support plate  20  during the bending or crimping process of the flexible display panel  100  can be deformed in coordination with the adjacent glue layer and the film layer, thereby reducing the risk of the film layer peeling and broken during the bending or crimping process of the flexible display panel  100 . 
     Further, as shown in  FIG.  6   , in the second direction x, a distance B1 between any adjacent grooves  21  is less than a width B2 of the groove  21 . 
     During bending or crimping of the support plate  20 , the support spoke  23  between the adjacent grooves  21  is hardly deformed, and since the thickness H2 in the third direction z is greater than the thickness H1 between the bottom of the groove  21  and the bottom of the support plate  20 , the support spoke  23  can maintain good support performance of the support plate  20  and ensure flatness of the flexible display panel body  10  in the unfolded state. However, if a width of the support spoke is too large, the bending rigidity of the crimping portion  201  is too large, and the bending performance cannot meet the requirements of the flexible display panel. Therefore, the distance B1 between any adjacent grooves  21  is limited to be less than the width B2 of the groove  21  so that the bending performance and rigidity performance of the support plate  20  can be balanced. 
     In practical use, the distance B1 between any adjacent grooves  21  may also be greater than or equal to the width B2 of the groove  21 , which is not limited here. 
       FIG.  8    is a plan schematic diagram of the deformation unit provided in an embodiment of the present application.  FIG.  9    is a relational graph of a length of a first patterned structure as a function of a bending stress and rebounding force. It can be seen from  FIG.  9    that a length L of the first patterned structure  22  in the first direction y is negatively correlated with the bending stress and the rebound stress of the support plate  20 . The greater the length L of the first patterned structure  22  is, the less the bending stress and the rebound stress of the support plate  20  are. 
     In an embodiment of the present application, a fatigue limit stress reference value of raw material of the support plate after 200000 times of crimping is 1000 MPa, and the material selection limit breaking strength value of the support plate  20  is 1600 MPa. Taking the intermediate patterned structure  221  in  FIG.  10    as an example, a length L of the intermediate patterned structure  221  in the first direction y is 6 mm, and the stress value of the support plate  20  is less than the fatigue limit stress reference value of the raw material of the support plate  20 . In practical use, the length L of the intermediate patterned structure  221  in the first direction y is not limited to 4 mm in the above-described embodiment, but may be 3.5 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, or the like, and only needs to be greater than or equal to 3.5 mm and less than or equal to 6 mm. 
     In an embodiment of the present application, the length of the edge patterned structure  222  in the first direction y should be less than the length L of the intermediate patterned structure  221 . 
     Further, in the second direction x, a distance c between any adjacent first patterned structures  22  is less than a width d of the first patterned structures  22 . 
       FIG.  10    is a relational graph of a width of a first patterned structure in a second direction x as a function of a bending stress and rebounding force. Taking the intermediate patterned structure  221  shown in  FIG.  8    as an example, the width d of the intermediate patterned structure  221  in the second direction x is positively correlated with the bending stress of the support plate  20 , that is, the greater the width d of the intermediate patterned structure  221  in the second direction x is, the greater the bending stress of the support plate  20  is, and when the width d of the intermediate patterned structure  221  in the second direction x is greater than 180 μm, the rate at which the bending stress of the support plate  20  increases is greater, and the bending stress of the support plate  20  gradually approaches and exceeds the fatigue limit stress reference value 1000 MPa of the raw material of the support plate  20 . 
     When the width d of the intermediate patterned structure  221  in the second direction x is less than or equal to 180 μm, the width d of the intermediate patterned structure  221  in the second direction x is positively correlated with the rebounding force of the support plate  20 , that is, the greater the width d of the intermediate patterned structure  221  in the second direction x is, the greater the rebounding force of the support plate  20  is, and when the width d of the intermediate patterned structure  221  in the second direction x is greater than or equal to 180 μm, the width d of the intermediate patterned structure  221  in the second direction x is negatively correlated with the rebounding force of the support plate  20 , that is, the greater the width d of the intermediate patterned structure  221  in the second direction x is, the less the rebounding force of the support plate  20  is. 
       FIG.  11    is a relational graph of a distance between adjacent first patterned structures as a function of a bending stress and rebounding force provided in an embodiment of the present application. Taking the intermediate patterned structure  221  shown in  FIG.  8    as an example, the distance c between adjacent intermediate patterned structures  221  is positively correlated with the bending stress and the rebounding force of the support plate  20 . That is, the greater the distance c between adjacent intermediate patterned structures  221  is, the greater the bending stress and the rebounding force of the support plate  221  are. As can be seen from  FIGS.  12  and  13   , if the distance c between any adjacent intermediate patterned structures  221  is less than the width d of the intermediate patterned structure  221 , the bending stress of the support plate  20  at the crimping portion  201  can be reduced, and the bending performance of the crimping portion  201  can be improved. 
     Further, in the second direction, a ratio of the distance between any adjacent first patterned structures  22  to the width of the first patterned structures  22  is greater than or equal to 0.4 and less than or equal to 0.6. 
     In an embodiment of the present application, taking the intermediate patterned structure  221  in  FIG.  8    as an example, the width d of the intermediate patterned structure  221  in the second direction x is 200 μm, the distance c between any adjacent intermediate patterned structures  221  is 100 μm, and a ratio of the width d of the intermediate patterned structure  221  in the second direction x to the distance c between any adjacent intermediate patterned structure  221  is 0.5. 
     In practical use, the width d of the intermediate patterned structure  221  in the second direction x is not limited to 200 μm in the above-described embodiment, but may be 150 μm, 180 μm, 220 μm, or 240 μm, or the like, and only needs to be greater than or equal to 150 μm and less than or equal to 240 μm. The distance c between any adjacent intermediate patterned structures  221  is not limited to 100 μm in the above-described embodiment, but may be 20 μm, 40 μm, 60 μm, 80 μm, or 120 μm, or the like, and only need to be greater than or equal to 20 μm and less than or equal to 120 μm. A ratio of the distance c between any adjacent intermediate patterned structures to the width d of the intermediate patterned structures is not limited to 0.5 in the above-described embodiment, but may be 0.4 or 0.6 or the like, and only needs to be greater than or equal to 0.4 and less than or equal to 0.6. 
     In an embodiment of the present application, a width of the edge patterned structure  222  in the second direction x is same as the width of the intermediate patterned structure  221  in the second direction x. 
     In an embodiment of the present application, a distance between the edge patterned structure  222  and adjacent first patterned structure  22  in the second direction x is same as the distance between the adjacent first patterned structures  22 . 
     In an embodiment of the present application, a bending radius R when the support plate is in the bending state is 3.6 mm. In practical use, the bending radius R when the support plate  20  is in the bending state is not limited to the above-described 3.6 mm, and the curvature radius when the support plate  20  is in the bending state can be selected according to an actual requirement. After determining the bending radius of the flexible display panel  10 , the thickness of the support plate  20 , and the depth of the groove  21 , the length L1 of the first patterned structure  22 , the width b of the first patterned structure and the distance c between the adjacent first patterned structures can be determined by mechanical simulation analysis and actual test results, so that the crimping portion  201  of the support plate  20  has the optimum bending performance and the risk of film peeling or fracture failure of the flexible display panel  100  is reduced. 
     Further, the support plate  20  further includes a transition portion  203  connected to the crimping portion  201 , the transition portion  203  is provided with a plurality of second patterned structures  24 . 
     As shown in  FIG.  2   , the support plate  20  has two transition portions  203  respectively disposed on opposite sides of the crimping portion  201  and connected to the crimping portion  201 , and a non-crimping portion  202  is disposed on a side of the transition portion  203  away from the crimping portion  201  and connected to the transition portion  203 . 
     In one embodiment, as shown in  FIG.  4   , the second patterned structure  24  may extend through the support plate  20  in the third direction z. Thus, the rigidity of the transition portion  203  can be reduced and the bending performance of the transition portion can be improved. In the process of crimping or bending the support plate  20 , it is possible to avoid an occurrence of fracture failure of the support plate due to excessive force on the transition portion  203 , thereby improving the tensile resistance and reliability of the support plate  20 . 
     In one embodiment, the second patterned structure  24  may also protrude into the support plate  20  in the third direction z, but not through the support plate  20 . Thus, the rigidity of the transition portion  203  can be reduced to some extent and the bending performance of the transition portion  203  can be improved. 
     Further, the second patterned structure  24  extends along the first direction y in which at least two of the second patterned structures  24  are disposed side by side, and any two adjacent second patterned structures  24  are disposed side by side or staggered in the second direction x. 
     In one embodiment, as shown in  FIG.  4   , in the first direction y, a plurality of second patterned structures  24  are spaced and disposed side by side to form a row of second patterned structures  24 . In the second direction x, the transition portion  203  is provided with a plurality of rows of second patterned structures  24 , and any two adjacent second patterned structures  24  of any two adjacent rows of second patterned structures  24  are disposed side by side. 
     In one embodiment, in the first direction y, a plurality of second patterned structures  24  are spaced and disposed side by side to form a row of second patterned structures  24 . In the second direction x, the transition portion  203  is provided with a plurality of rows of second patterned structures  24 , and any two adjacent second patterned structures  24  of any two adjacent rows of second patterned structures  24  may be staggered. 
     Further, the density of the second patterned structure  24  is less than the density of the first patterned structure  22  by reducing the density of the second patterned structure  24  in the transition portion  203 , the rigidity of the transition portion  203  can be appropriately reduced, thereby avoiding the occurrence of fracture failure due to excessive local stress on the transition portion  203 . 
     Further, the length of the second patterned structure  24  in the first direction y is less than the length of the first patterned structure  22  in the first direction y. Since the length of the second patterned structure  24  is negatively correlated with the bending stress and the rebounding force of the support plate  20 , the bending rigidity of the transition portion  203  is greater than the bending rigidity of the crimping portion  201 , so that not only the occurrence of fracture failure due to the excessive local force of the transition portion  203  is avoided, but also the support property of the support plate  203  can be improved, thereby ensuring the flatness of the flexible display panel  100  in the unfolded state. 
     Further, in the second direction x, the distance between any adjacent second patterned structures  24  is greater than the distance between any adjacent first patterned structures  22 . It can be understood that the distance between the adjacent second patterned structures  24  is positively correlated with the rigidity of the transition portion  203 , and the greater the distance between the adjacent second patterned structures  24  is, the greater the rigidity of the transition portion  203  is. In this way, the rigidity of the transition portion  203  can be greater than the rigidity of the crimping portion  201  while satisfying that the transition portion  203  has a certain deformation capability, so that the occurrence of fracture failure due to excessive local force on the transition portion  203  can be avoided, and the support property of the transition portion  203  can be ensured. 
     Further, in the second direction x, a ratio of the distance between any adjacent second patterned structures  24  to the distance between any adjacent first patterned structures  22  is 2. In practical use, a ratio of the distance between any adjacent second patterned structures  24  to the distance between any adjacent first patterned structures  22  is not limited to 2 in the above-described embodiment, but may be 1.2, 1.5, or 1.8, or the like, and only needs to be greater than or equal to 1.2 and less than or equal to 2. 
     In an embodiment of the present application, in the second direction x, the width of the first patterned structure  22  is same as the width of the second patterned structure  24 , thereby ensuring the consistency of the processing of the first patterned structure  22  and the second patterned structure  24 , thereby reducing the processing difficulty of the support plate. 
     A display device is provided in an embodiment of the present application, as shown in  FIG.  12   ,  FIG.  12    is a structural schematic diagram of a display device in a retracted state provided in an embodiment of the present application. The display panel includes a first middle frame  200 , a second middle frame  300 , and a flexible display panel  100  as described in the above-described embodiment. A portion of the flexible display panel may be fixed to the first middle frame  200  for realizing an image display function in the retracted state. A non-crimping portion  202  of the support plate  20  used for supporting the portion of the flexible display panel body is disposed in the first middle frame  200 . Another portion of the flexible display panel  100  may be retracted in an accommodation space in the first middle frame  200  and the second middle frame  300 , thereby improving the portability of the display device. The crimping portion  201  of the support plate  20  is used to support the portion of the flexible display panel  100  retracted in the first middle frame  200  and the second middle frame  300 , and is used to drive the portion of the flexible display panel to slide. 
     As shown in the  FIG.  13   , which is a structural schematic diagram of the display device provided in an embodiment of the present application in an unfolded state, the second middle frame  300  is slidably connected to the first middle frame  200 . In a process in which the second middle frame  300  gradually moves away from the first middle frame  200  along the second direction x, the portion of the flexible display panel  100  accommodated in the accommodation space of the first middle frame  200  and the second middle frame  300  may gradually appear, and may be on a same plane as the portion of the flexible display panel  100  that are not accommodated, thus realizing a function of larger area display in the unfolded state. 
     During a process in which the display device stretches from the retracted state to the unfolded state, the crimping portion  201  of the support plate  20  may gradually slide through an arcuate side wall of the second middle frame  300  to a same plane as the non-crimping portion  202 , and drive the flexible display panel body  20  fixed to the crimping portion  201  to gradually appear from the accommodation space of the first middle frame  200  and the second middle frame  300 . 
     In an embodiment of the present application, the support plate  20  is provided with only one crimping portion  201 , only the second middle frame  300  in the display device can be stretched unilaterally with respect to the first middle frame  200 , and the crimping portion  201  slides through the arcuate side wall of the second middle frame  300 . In practical use, the support plate  20  may have two or more crimping portions  201  when the display device can be stretched bilaterally or multilaterally. 
     The display device provided in an embodiment of the present application may be a mobile terminal such as a smartphone, a tablet computer, a notebook computer, or the like, or the display device may also be a wearable terminal such as a smartwatch, a smart band, smart glasses, an augmented reality device, or the display device may also be a fixed terminal such as a desktop computer, a television, or the like. 
     In an embodiment of the present application, the display device may further include a winding mechanism for rendering the flexible display panel  100  to be in an unfolded state or a retracted state, and electronic components such as a power supply and a drive integrated circuit board for driving the flexible display panel to implement a screen display function. The winding structure, the power supply, the drive integrated circuit board, and the like may be disposed in the accommodation space of the first middle frame  200  and/or the second middle frame  300 . 
     An embodiment of the present application provides a flexible display panel and a display device. The display device includes a flexible display panel, the flexible display panel includes a flexible display panel body and a support plate, the support plate is provided at a bottom of the flexible display panel body, the support plate has a crimping portion. A plurality of grooves extending along the first direction and spaced along the second direction are provided at the crimping portion, and a plurality of first patterned structures are provided at a bottom of the grooves, so that a bending performance of the crimping portion can be improved while the rigidity of the crimping portion is ensured, thereby balancing crimpiness and flatness of the flexible display panel in the display device. 
     In summary, although the present application discloses the foregoing preferred embodiment, the foregoing preferred embodiment is not intended to limit the present application. A person of ordinary skill in the art may make various changes and finishes without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application is based on the scope defined by the claims.