Patent Publication Number: US-2021193941-A1

Title: Flexible organic light-emitting diode display panel and flexible organic light-emitting diode display device

Description:
FIELD OF INVENTION 
     The present application relates to a field of display technologies, and more particularly to a flexible organic light-emitting diode display panel and a flexible organic light-emitting diode display device. 
     BACKGROUND OF INVENTION 
     In the field of display technologies, flat panel display devices, such as liquid crystal displays (LCD) and organic light-emitting diodes (OLED), have gradually replaced cathode line displays. 
     Among the flat panel display devices, OLED display panels have many advantages, such as being self-luminous, having a low driving voltage and high electroluminescent efficiency, high resolution, contrast, and capacity to achieve flexible display panels, and large scale full-color displays. 
     A conventional OLED display panel includes a base substrate, and a display module disposed on the base plate. The display module includes a substrate disposed on the base substrate, a thin film transistor disposed on the substrate, a patterned pixel-definition layer disposed on the thin film transistor, and an OLED element disposed within the pixel-definition layer. A double-layer polyimide (PI) film is generally used to serve as the base substrate. However, when the PI film is being folded, the PI film may be irreversibly damaged due to a compression force received by an inner ring of the PI film, and a tensile force received by an outer ring of the PI film. 
     Therefore, it is necessary to provide a flexible OLED display panel with a substrate structure which is capable of buffering the compression force and the tensile force in order to solve the abovementioned technical problems. 
     SUMMARY OF INVENTION 
     The embodiment of the present application provides a flexible organic light-emitting diode (OLED) display panel and a flexible OLED display device having substrate structures which are capable of buffering the compression force and the tensile forces, so as to solve the technical problem that the substrate of the existing OLED display panel is prone to damage when it is folded. 
     An embodiment of the present application provides a flexible organic light-emitting diode (OLED) display panel, comprising: 
     a folding section for folding, wherein a substrate structure is disposed at the folding section and an OLED display module is disposed on the substrate structure, wherein the substrate structure comprises: 
     a base substrate; and 
     a flexible structural layer disposed on the base substrate, wherein the flexible structural layer comprises at least two flexible layers arranged one on the other; 
     wherein the flexible layers comprise a plurality of sets of relief holes defined within the folding section, and the relief holes of the adjacent flexible layers are staggered with respect to each other; 
     wherein, when the OLED display panel is in a folded state, a diameter of the relief holes of one of the flexible layers which is located at an inner ring of the folding section is reduced by a compression force so as to buffer the compression force received by the flexible layer; and a diameter of the relief holes of another of the flexible layers, which is located at an outer ring of the folding section, is enlarged by a tensile force so as to buffer the tensile force received by the flexible layer; and 
     wherein shapes of the relief holes of each set of the relief holes are selected from one or any two of a point, a rectangle, a diamond, and a circle; and the adjacent sets of the relief holes in the same flexible layer are staggered with respect to each other. 
     In a first embodiment of the flexible OLED display panel of the present application, the flexible structural layer comprises two of the flexible layers, a first flexible layer is disposed on the base substrate, and a second flexible layer is disposed on the first flexible layer; when the flexible OLED display panel is inwardly folded, the first flexible layer is located at the outer ring of the folding section, and the second flexible layer is located at the inner ring of the folding section, and 
     wherein a number of the sets of the relief holes of the first flexible layer is more than a number of the sets of the relief holes of the second flexible layer. 
     In the first embodiment of the flexible OLED display panel of the present application, the number of the sets of the relief holes of the second flexible layer is one more than the number of the sets of the relief holes of the first flexible layer. 
     In a second embodiment of the flexible OLED display panel of the present application, the flexible structural layer comprises two of the flexible layers, a first flexible layer is disposed on the base substrate, and a second flexible layer is disposed on the first flexible layer; when the flexible OLED display panel is outwardly folded, the first flexible layer is located at the inner ring of the folding section and the second flexible layer is located at the outer ring of the folding section, and 
     wherein a number of the sets of the relief holes of the second flexible layer is more than a number of the sets of the relief holes of the first flexible layer. 
     In a third embodiment of the flexible OLED display panel of the present application, the flexible structural layer comprises three of the flexible layers, a first flexible layer is disposed on the base substrate, a second flexible layer is disposed on the first flexible layer, and a third flexible layer is disposed on the second flexible layer; and 
     wherein a number of the sets of the relief holes of the first flexible layer is equal to a number of the sets of the relief holes of the second flexible layer, and a number of the sets of the relief holes of the second flexible layer is less than the number of the sets of the relief holes of the first flexible layer. 
     In the third embodiment of the flexible OLED display panel of the present application, the number of the sets of the relief holes of the second flexible layer is one less than the number of the sets of the relief holes of the first flexible layer. 
     In the flexible OLED display panel of the present application, the flexible layers are polyimide layers. 
     The present application provides an additional flexible organic light-emitting diode (OLED) display panel, comprising: 
     a substrate structure and an OLED display module disposed on the substrate structure, wherein the substrate structure comprises: 
     a base substrate; and 
     a flexible structural layer disposed on the base substrate, wherein the flexible structural layer comprises at least two flexible layers arranged one on the other; 
     wherein the OLED display panel comprises a folding section for folding, the flexible layers comprise a plurality of sets of relief holes defined within the folding section, and the relief holes of the adjacent flexible layers are staggered with respect to each other; and 
     wherein, when the OLED display panel is in a folded state, a diameter of the relief holes of one of the flexible layers which is located at an inner ring of the folding section is reduced by a compression force so as to buffer the compression force received by the flexible layer; and a diameter of the relief holes of another of the flexible layers which is located at an outer ring of the folding section is enlarged by a tensile force so as to buffer the tensile force received by the flexible layer. 
     In an additional first embodiment of the flexible OLED display panel of the present application, the flexible structural layer comprises two of the flexible layers, a first flexible layer is disposed on the base substrate, and a second flexible layer is disposed on the first flexible layer; when the flexible OLED display panel is inwardly folded, the first flexible layer is located at the outer ring of the folding section, and the second flexible layer is located at the inner ring of the folding section, and 
     wherein a number of the sets of the relief holes of the first flexible layer is more than a number of the sets of the relief holes of the second flexible layer. 
     In the additional first embodiment of the flexible OLED display panel of the present application, the number of the sets of the relief holes of the second flexible layer is one more than the number of the sets of the relief holes of the first flexible layer. 
     In the additional first embodiment of the flexible OLED display panel of the present application, the flexible structural layer is composed of the first flexible layer and the second flexible which are arranged one on the other. When the flexible OLED display panel is inwardly folded, i.e., the OLED display panel is folded towards the OLED display module, the relief holes of the first flexible layer and the relief holes of the second flexible layer are staggered with respect to each other, so that all the relief holes achieve respective supports, not affecting normal uses. 
     In addition, when being inwardly folded, a compassion force is received by the second flexible layer and a tensile force is received by the first flexible layer. Therefore, in order to further buffer the tensile force, the number of the sets of the relief holes of the second flexible layer is more than the number of the sets of the relief holes of the first flexible layer. 
     In the additional second embodiments of the present application, it is different from the additional first embodiment in that the flexible structural layer comprises two of the flexible layers, a first flexible layer is disposed on the base substrate, and a second flexible layer is disposed on the first flexible layer; when the flexible OLED display panel is outwardly folded, the first flexible layer is located at the inner ring of the folding section and the second flexible layer is located at the outer ring of the folding section, and 
     wherein a number of the sets of the relief holes of the second flexible layer is more than a number of the sets of the relief holes of the first flexible layer. 
     In the additional second embodiments of the present application, the number of the sets of the relief holes of the second flexible layer is one more than the number of the sets of the relief holes of the first flexible layer. 
     In an additional third embodiments of the present application, it is different from another third embodiment and the additional first embodiment in that the flexible structural layer comprises three of the flexible layers, a first flexible layer is disposed on the base substrate, a second flexible layer is disposed on the first flexible layer, and a third flexible layer is disposed on the second flexible layer; and 
     wherein a number of the sets of the relief holes of the first flexible layer is equal to a number of the sets of the relief holes of the second flexible layer, and a number of the sets of the relief holes of the second flexible layer is less than the number of the sets of the relief holes of the first flexible layer. 
     In an additional third embodiments of the present application, the number of the sets of the relief holes of the second flexible layer is one less than the number of the sets of the relief holes of the first flexible layer. 
     In an additional third embodiments of the present application, the number of the sets of the relief holes of the first flexible layer adjacent to the base substrate and the third flexible layer adjacent to the OLED display module are more than the number of the sets of the relief holes of the second flexible layer, so that both in-folding and out-folding of the OLED display panel can be achieved without damaging the substrate structure. 
     In addition, in the additional first embodiment, the additional second embodiment, and the additional third embodiment, the flexible layers are polyimide layer. 
     In the additional first embodiment, the additional second embodiment, shapes of the relief holes of each set of the relief holes are selected from one or any two of a point, a rectangle, a diamond, and a circle. 
     In the additional first embodiment, the additional second embodiment, the adjacent sets of the relief holes in the same flexible layer are staggered with respect to each other 
     The present application further relates to a flexible OLED display device, comprising: 
     a flexible OLED display panel, the flexible OLED display panel comprises a folding section for folding, wherein a substrate structure is disposed at the folding section and an OLED display module is disposed on the substrate structure, wherein the substrate structure comprises: 
     a base substrate; and 
     a flexible structural layer disposed on the base substrate, wherein the flexible structural layer comprises at least two flexible layers arranged one on the other; 
     wherein the flexible layers comprise a plurality of sets of relief holes defined within the folding section and the relief holes of the adjacent flexible layers are staggered with respect to each other; and 
     wherein, when the OLED display panel is in a folded state, a diameter of the relief holes of one of the flexible layers which is located at an inner ring of the folding section is reduced by a compression force so as to buffer the compression force received by the flexible layer; and a diameter of the relief holes of another of the flexible layers which is located at an outer ring of the folding section is enlarged by a tensile force so as to buffer the tensile force received by the flexible layer. 
     In a first embodiment of the flexible OLED display device, the flexible structural layer comprises two of the flexible layers, a first flexible layer is disposed on the base substrate, and a second flexible layer is disposed on the first flexible layer; when the flexible OLED display panel is inwardly folded, the first flexible layer is located at the outer ring of the folding section, and the second flexible layer is located at the inner ring of the folding section. 
     In a first embodiment of the flexible OLED display device, a number of the sets of the relief holes of the first flexible layer is more than a number of the sets of the relief holes of the second flexible layer. 
     In the first embodiment of the flexible OLED display device, the number of the sets of the relief holes of the first flexible layer is one more than the number of the sets of the relief holes of the second flexible layer. 
     The flexible OLED display panel further comprises a second embodiment and a third embodiment of the abovementioned flexible OLED display panel. Please refer to the content of the abovementioned flexible OLED display panel of the present application for details. 
     Compared with the OLED display panels of the prior art, the flexible OLED display panel and the flexible OLED display device of the present application disposes a flexible structural layer having at least two flexible layer and the relief holes of the adjacent flexible layers are staggered to each other. On one hand, all the relief holes achieve respective supports to avoid adverse effects. 
     On the other hand, when the OLED display panel is folded, a diameter of the relief holes of the flexible layer which is located at an inner ring of the bending section is reduced by a compression force so as to buffer the compression force. A diameter of the relief holes of the flexible layer which is located at an outer ring of the bending section is enlarged by a tensile force so as to buffer the tensile force. The OLED display panel is prevented from being damaged when it is folded. 
     The present application solves the technical problem that the substrates of the existing OLED display panels are prone to damage when they are folded. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       In order to illustrate a technical solution in the embodiments of the present application or in the prior art more clearly, the accompanying drawings required in the embodiments are introduced briefly hereafter. The accompanying drawings in the following description are merely part of the embodiments of the present application. Based upon the accompanying drawings, people with ordinary skills in the art can obtain other drawings without making inventive efforts. 
         FIG. 1  is a cross-sectional structural view of a first embodiment of a flexible organic light-emitting diode (OLED) display panel of the present application, shown in a flattened state; 
         FIG. 2  is a cross-sectional structural view of the first embodiment of the flexible OLED display panel of the present application, shown in a folded state; 
         FIG. 3  is a top structural view of a first flexible layer and a second flexible layer of the first embodiment of the flexible OLED display panel of the present application; 
         FIG. 4  is a cross-sectional structural view of a second embodiment of the flexible OLED display panel of the present application, shown in a flattened state; 
         FIG. 5  is a cross-sectional structural view of the second embodiment of the flexible OLED display panel of the present application, shown in a folded state; 
         FIG. 6  is a top structural view of the first flexible layer and the second flexible layer of the second embodiment of the flexible OLED display panel of the present application; and 
         FIG. 7  is a cross-sectional structural view of a third embodiment of the flexible OLED display panel of the present application, shown in a flattened state. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to the drawings in the accompanying drawings, same reference numerals represent same components. The following description is based on the detailed embodiments of the present invention as exemplified, and should not be construed as a limitation to other embodiments of the present application which are not described herein in detail. 
     Please refer to  FIG. 1-3 ,  FIG. 1  is a cross-sectional structural view of a first embodiment of a flexible OLED display panel of the present application, shown in a flattened state;  FIG. 2  is a cross-sectional structural view of the first embodiment of the flexible OLED display panel of the present application, shown in a folded state;  FIG. 3  is a top structural view of a first flexible layer and a second flexible layer of the first embodiment of the flexible OLED display panel of the present application. 
     A flexible OLED display panel according to the first embodiment of the present application includes a substrate structure and an OLED display module  11  disposed on the substrate structure. The substrate structure comprises a base substrate  12  and a flexible structural layer  13 . The OLED display module comprises a substrate disposed on the substrate structure, a thin film transistor disposed on the substrate, a patterned pixel-definition layer disposed on the thin film transistor, and an OLED element disposed within the pixel-definition layer. 
     In particular, the flexible structural layer  13  is disposed on the base substrate  12 , and the flexible structural layer  13  is formed by superposing at least two flexible layers. 
     The OLED display panel comprises a folding portion A 1  for folding, and the flexible layer includes a plurality of sets of the relief holes  131  disposed in the folding section, and the relief holes  131  of the adjacent flexible layers  13  are staggered with respect to each other. 
     When the OLED display panel is in a folded state, a diameter of the relief holes  131  of the flexible layer which is located at an inner ring of the folding section A 1  is reduced by a compression force so as to buffer the compression force received by the flexible layer, and a diameter of the relief holes  131  of the flexible layer which is located at an outer ring of the folding section A 1  is enlarged by a tensile force so as to buffer the tensile force received by the flexible layer. 
     On one hand, the adjacent sets of the relief holes in the same flexible layer are staggered with respect to each other, so that all the relief holes achieve respective supports, not affecting normal use. On the other hand, the disposing of at least two soft layers increases flexibility and guarantees a certain supportive force. 
     In addition, when the flexible OLED display panel is inwardly folded (i.e., the OLED display panel is folded towards the OLED display module), the diameter of the relief holes  131  of the flexible layer which is located at an inner ring of the folding section A 1  is reduced by the compression force so as to buffer the compression force received by the flexible layer; and the diameter of the relief holes  131  of the flexible layer which is located at an outer ring of the folding section A 1  is enlarged by the tensile force so as to buffer the tensile force received by the flexible layer. Accordingly, the OLED display panel is prevented from being damaged when it is folded. 
     In addition, the flexible layer is a polyimide layer, and polyimide possesses excellent mechanical properties. 
     In particular, in the first embodiment of the present application, the flexible structural layer comprises two of the flexible layers, a first flexible layer  132  is disposed on the base substrate  12 , and a second flexible layer  133  is disposed on the first flexible layer  132 . When the flexible OLED display panel is inwardly folded, the first flexible layer  132  is located at the outer ring of the folding section A 1  and the second flexible layer  133  is located at the inner ring of the folding section A 1 . 
     A number of the sets of the relief holes of the first flexible layer is greater than a number of the sets of the relief holes of the second flexible layer. Such an arrangement not only buffers the compression force received by the first flexible layer  132 , but also further buffers the tensile force received by the first flexible layer. 
     Furthermore, the number of the sets of the relief holes  131  of the second flexible layer  133  is one more than the number of the sets of the relief holes  131  of the first flexible layer  132 . 
     Because—the first flexible layer  132  and the second flexible layer  133  are thin, the flexibility and support force of the first flexible layer  132  located in the folding area A 1  are reduced if a plurality of sets of the relief holes  131  are defined on the first flexible layer  132 . Therefore, in a case where the compression force and the tensile force are buffered without damaging the substrate structure, it is most preferred that there is one more set of relief holes  131  of the first flexible layer  132  than the sets of the relief holes  131  of the second flexible layer  133 . 
     In the present first embodiment, shapes of the relief holes of each set of the relief holes  131  are selected from one or any two of a point, a rectangle, a diamond, and a circle. The shape of each of the relief holes  131  could be a line, etc. The shapes of the relief holes  131  are not limited thereto. 
     Please refer to  FIG. 3 , in the present first embodiment, the first flexible layer  132  is provided with six sets of the relief holes  131 , and each set of the relief holes  131  is formed by a plurality of rectangular relief holes  131  arranged side by side. The second flexible layer  133  is provided with five sets of the relief holes  131 , and each set of the relief holes  131  is formed by a plurality of rectangular relief holes  131  arranged side by side. 
     In addition, the adjacent sets of the relief holes  131  in the same flexible layer are staggered with respect to each other to improve mechanical equilibrium in the same flexible layer when the flexible layer is folded. 
     When the first embodiment is folded, the principle of folding the substrate structure is that when the OLED display panel is in a folded state, a diameter of the relief holes of the second flexible layer  133  which is located at an inner ring of the flexible structural layer  13  of the folding section A 1  is reduced by a compression force so as to buffer the compression force received by the second flexible layer  133 . Meanwhile, a diameter of the relief holes  131  of the first flexible layer  132  which is located at an outer ring of the flexible structural layer  13  of the folding section A 1  is enlarged by a tensile force and the compassion force so as to buffer the tensile force and the compassion force received by the first flexible layer  132 . 
     Please refer to  FIG. 4-6 ,  FIG. 4  is a cross-sectional structural view of a second embodiment of the flexible OLED display panel of the present application, shown in a flattened state;  FIG. 5  is a cross-sectional structural view of the second embodiment of the flexible OLED display panel of the present application, shown in a folded state; and  FIG. 6  is a top structural view of the first flexible layer and the second flexible layer of the second embodiment of the flexible OLED display panel of the present application. 
     In the second embodiment of the present application, the OLED display panel comprises a substrate structure and an OLED display module  21 . The substrate structure includes a base substrate  22  and a flexible structural layer  23 . 
     The second embodiment is different from the first embodiment in that the flexible structural layer in the second embodiment comprises two of the flexible layers, a first flexible layer  232  is disposed on the base substrate  22 , and a second flexible layer  233  is disposed on the first flexible layer  232 . When the flexible OLED display panel is outwardly folded, the first flexible layer  232  is located at the inner ring of the folding section A 2  and the second flexible layer  233  is located at the outer ring of the folding section A 2 , and 
     wherein a number of the sets of the relief holes  231  of the second flexible layer  233  is more than a number of the sets of the relief holes  231  of the first flexible layer  232 . Such an arrangement not only buffers the compression force received by the second flexible layer  233 , but also further buffers the tensile force received by the second flexible layer  233 . 
     In the second embodiment, the number of the sets of the relief holes  231  of the second flexible layer  233  is one more than the number of the sets of the relief holes  231  of the first flexible layer  232 . 
     In the present second embodiment, shapes of the relief holes  231  of each set of the relief holes are selected from one or any two of a point, a rectangle, a diamond, and a circle. The shape of each of the relief holes  231  could be a line, etc. The shapes of the relief holes  231  are not limited thereto. 
     Please refer to  FIG. 6 , in the present second embodiment, the first flexible layer  232  is provided with five sets of the relief holes  231 , among which, two of the sets of the relief holes  231  are composed of a plurality of rectangular relief holes  231  arranged side by side, and three of the sets of the relief holes  231  are composed of a plurality of diamond relief holes  231  arranged side by side. Each set of the rectangular relief holes  231  and each set of the diamond relief holes  231  are alternately arranged. The second flexible layer  233  is provided with six sets of the relief holes  231 , among which, three of the sets of the relief holes  231  are composed of a plurality of rectangular relief holes  231  which are arranged side-by-side, and three of the sets of the relief holes  231  are composed of a plurality of diamond-shaped relief holes  231  arranged side by side. Each set of the rectangular relief holes  231  and each set of the diamond relief holes  231  are alternately arranged. 
     In addition, the adjacent sets of the relief holes  231  in the same flexible layer staggered with respect to each other to improve mechanical equilibrium in the same flexible layer when the flexible layer is folded. 
     When the second embodiment is folded, the principle of folding of the substrate structure is that when the OLED display panel is outwardly folded (i.e., the OLED display panel is folded towards the base substrate  22 ), a diameter of the relief holes  231  of the first flexible layer  232  which is located at an inner ring of the flexible structural layer  23  of the folding section A 2  is reduced by a compression force so as to buffer the compression force received by the first flexible layer  232 . Meanwhile, a diameter of the relief holes  231  of the second flexible layer  233  which is located at an outer ring of the flexible structural layer  23  of the folding section A 2  is enlarged by a tensile force and the compassion force so as to buffer the tensile force and the compassion force received by the second flexible layer  233 . 
     Please refer to  FIG. 7 ,  FIG. 7  is a cross-sectional structural view of a third embodiment of a flexible OLED display panel of the present application, shown in a flattened state. The OLED display panel of the third embodiment of the present application comprises a substrate structure and an OLED display module  31 . The substrate structure comprises a base substrate  32  and a flexible structural layer  33  disposed on the base substrate  32 . The flexible structural layer  33  comprises at least two flexible layers. 
     The third embodiment is different from the first embodiment in that the flexible structural layer comprises three of the flexible layers, a first flexible layer  332  is disposed on the base substrate  32 , a second flexible layer  333  is disposed on the first flexible layer  332 , and a third flexible layer  334  is disposed on the second flexible layer  333 . 
     A number of the sets of the relief holes  331  of the first flexible layer  332  is equal to a number of the sets of the relief holes  331  of the second flexible layer  333 , and the number of the sets of the relief holes  331  of the second flexible layer  333  is less than the number of the sets of the relief holes  331  of the first flexible layer  332 . 
     In the third embodiment, the number of the sets of the relief holes  331  of the second flexible layer  333  is one less than the number of the sets of the relief holes  331  of the first flexible layer  332 . 
     The number of the sets of the relief holes  331  of the first flexible layer  332  adjacent to the base substrate  32  and the third flexible layer  334  adjacent to the OLED display module  31  are more than the number of the sets of the relief holes  331  of the second flexible layer  333 , so that both in-folding and out-folding of the OLED display panel can be achieved without damaging the substrate structure. 
     In the third embodiment, the relief holes  331  of each set of the relief holes could be in any shapes, such as a rectangle, a diamond, a circle, a regular polygon, a line, etc. 
     In addition, the principle of folding of the OLED panel is that when the OLED display panel is inwardly folded, a diameter of the relief holes  331  of the first flexible layer  332  which is located at an outer ring of the folding section A 3  is enlarged by a tensile force and a compression force so as to buffer the tensile force and the compression force received by the first flexible layer  232 . A diameter of the relief holes  331  of the third flexible layer  334  which is located at an inner ring of the folding section A 3  is reduced by a compassion force so as to buffer the compassion force received by the third flexible layer  334 . The second flexible layer  333  which is located at a middle ring of the folding section A 3  is subject to the compassion force and the tensile force. A diameter of the relief holes  331  of the second flexible layer  333  which is adjacent to the first flexible layer is reduced, and a diameter of the relief holes  331  of the second flexible layer  333  which is adjacent to the third flexible layer  333  is enlarged so as to buffer the tensile force and the compression force received by the second flexible layer  333 . 
     When the OLED display panel is outwardly folded, the diameter of the relief holes  331  of the first flexible layer  332  which is located at the inner ring of the folding section A 3  is reduced by the compression force so as to buffer the compression force. A diameter of the relief holes  331  of the third flexible layer  334  which is located at the outer ring of the folding section A 3  is enlarged by the compression force and the tensile force so as to buffer the compression force and the tensile force received by the third flexible layer  334 . The second flexible layer  333  which is located at a middle ring of the folding section A 3  is subject to the compassion force and the tensile force. A diameter of the relief holes  331  of the second flexible layer  333  which is adjacent to the first flexible layer  332  is enlarged and a diameter of the relief holes  331  of the second flexible layer  333  which is adjacent to the third flexible layer  333  is reduced so as to buffer the tensile force and the compression force received by the second flexible layer  333 . 
     In addition, the present application further provides a flexible OLED display device comprising the abovementioned OLED flexible display panel. The flexible OLED display panel of the flexible OLED display device of the present application is consistent with the structure of the OLED flexible display panel described hereabove. Please refer to the content of the above flexible OLED display panel of the present application for details. 
     Accordingly, compared with the OLED display panels of prior art, the flexible OLED display panel of the present application disposes a flexible structural layer having at least two flexible layers and the relief holes of the adjacent flexible layers are staggered to each other. On one hand, all the relief holes achieve respective supports to avoid adverse effects. 
     On the other hand, when the OLED display panel is folded, a diameter of the relief holes of the flexible layer which is located at an inner ring of the bending section is reduced by a compression force so as to buffer the compression force. A diameter of the relief holes of the flexible layer which is located at an outer ring of the bending section is enlarged by a tensile force so as to buffer the tensile force. The OLED display panel is prevented from being damaged when it is folded. 
     The present application solves a technical problem that the substrates of existing OLED display panels are prone to damage when folded. 
     In summary, people with ordinary skills in the art may make various changes and modifications according to the technical solutions and technical concept of the present application, and all such changes and modifications fall into the protection scope of claims appended to the present application.