Flexible display panel and flexible display device

Abstract

The present disclosure provides a flexible display panel and a flexible display device, the flexible display panel comprising: a substrate substrate; a display unit on the substrate substrate; a support layer on the side of the substrate substrate away from the display unit; wherein the support layer comprises: a bending area; the bending area is provided with a plurality of slit structures; a plurality of slit structures are arranged in an array, wherein the row direction is the bending axis direction of the bending area, and there is a shift distance between adjacent two rows of slit structures, wherein the shift distance is less than or equal to a preset distance. The present disclosure sets the slit structure in the bending area of the support layer, reduces the rebound force of the bending area of the support layer when the flexible display panel is bent, limits the stagger distance of adjacent two rows of slit structures, reduces the thermal resistance of the bending area, improves the heat transfer performance of the bending area, and reduces the temperature difference between different areas of the flexible display panel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular, to a flexible display panel and a flexible display device. BACKGROUND

[0002] This section is intended to provide background information to facilitate a better understanding of embodiments of the present disclosure. It is not admitted that any of the information provided in this section is prior art merely because it is included in this section.

[0003] The flexible display device is a bendable or deformable display device with a flexible display panel.

[0004] Since the flexible display panel is relatively soft, a back surface needs to be supported by a support layer, and a metal material with relatively high strength can be used as the support layer. When the flexible display panel is bent, the area on the support layer corresponding to the bending area of the flexible display panel may cause distortion due to stress, aggravate the creases of the flexible display panel, and affect the service life of the flexible display panel. In order to reduce the rebound force of the support layer when the flexible display panel is bent, a cutting device is used to cut a slit structure on the support layer.

[0005] However, the slit structure hinders heat transfer, increases the temperature difference between different areas of the flexible display panel, and further causes color difference and overall temperature rise. SUMMARY

[0006] Therefore, the purpose of the present disclosure is to provide a flexible display panel and a flexible display device, which at least partially solve one of the technical problems in the related art.

[0007] To achieve the above purpose, in a first aspect, an embodiment of the present disclosure provides a flexible display panel, comprising:

[0008] a substrate substrate;

[0009] a display unit on the substrate substrate;

[0010] a support layer on a side of the substrate substrate away from the display unit;

[0011] The support layer comprises:

[0012] a bending area;

[0013] The bending area is provided with a plurality of slit structures;

[0014] The plurality of slit structures are arranged in an array, wherein the row direction is the bending axis direction of the bending area, and there is an offset distance between adjacent two rows of slit structures, wherein the offset distance is less than or equal to a preset distance.

[0015] In some exemplary embodiments, the preset distance includes one-quarter of the sum of the length and spacing of the slit structure in the row direction.

[0016] In some exemplary embodiments, the slit structure is offset alternately to the left and right in the column direction.

[0017] In some exemplary embodiments, the slit structure is offset along a first direction in the column direction.

[0018] In some exemplary embodiments, the slit structure is offset by a preset number of steps in the column direction along a first direction, and then offset by a preset number of steps in the column direction along a second direction;

[0019] The first direction and the second direction are opposite.

[0020] In some exemplary embodiments, the offset distance is different for different offsets when the slit structure is offset in the column direction.

[0021] In some exemplary embodiments, the depth of the slit structure is less than the thickness of the support layer.

[0022] In some exemplary embodiments, the difference between the depth of the slit structure and the thickness of the support layer is less than or equal to 60 μm.

[0023] In some exemplary embodiments, the slit structure is obtained by etching the support layer.

[0024] Based on the same inventive concept, a second aspect of the exemplary embodiments of this disclosure provides a flexible display device, including a flexible display panel as described in the first aspect.

[0025] As can be seen from the above description, the flexible display panel and flexible display device provided in this disclosure include: a substrate; a display unit located on the substrate; and a support layer located on the side of the substrate away from the display unit. The support layer includes: a bending region; the bending region is provided with multiple slit structures; the multiple slit structures are arranged in an array, wherein the row direction is the bending axis direction of the bending region, and there is an offset distance between adjacent rows of slit structures, wherein the offset distance is less than or equal to a preset distance. This disclosure reduces the rebound force of the bending region of the support layer when the flexible display panel is bent by providing slit structures in the bending region, and reduces the thermal resistance of the bending region by limiting the staggered distance between adjacent rows of slit structures, thereby improving the heat transfer performance of the bending region and reducing the temperature difference between different areas of the flexible display panel. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this disclosure or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a flexible display device in an unfolded state, provided as an exemplary embodiment of this disclosure;

[0028] Figure 2 A schematic diagram of a flexible display device in a bent state provided for an exemplary embodiment of the present disclosure;

[0029] Figure 3 A schematic diagram of the structure of a flexible display panel provided as an exemplary embodiment of the present disclosure;

[0030] Figure 4 A schematic diagram of a support layer provided for an exemplary embodiment of this disclosure;

[0031] Figure 5 A schematic diagram of the temperature distribution of a support layer provided for an exemplary embodiment of this disclosure;

[0032] Figure 6 A schematic diagram of the dimensions of a slit structure provided for an exemplary embodiment of this disclosure;

[0033] Figure 7 Another schematic diagram of the temperature distribution of the support layer provided for an exemplary embodiment of this disclosure;

[0034] Figure 8 Another schematic diagram of the support layer provided for an exemplary embodiment of this disclosure;

[0035] Figure 9 Another schematic diagram of the support layer provided for an exemplary embodiment of this disclosure;

[0036] Figure 10 Another schematic diagram of the support layer provided for an exemplary embodiment of this disclosure;

[0037] Figure 11 Another schematic diagram of the support layer provided for an exemplary embodiment of this disclosure;

[0038] Figure 12 A schematic diagram of a slit structure provided for an exemplary embodiment of the present disclosure;

[0039] Figure 13 Another schematic diagram of a slit structure provided for an exemplary embodiment of this disclosure;

[0040] Figure 14 Another schematic diagram of a slit structure provided for an exemplary embodiment of this disclosure;

[0041] Figure 15 Another schematic diagram of the temperature distribution of the support layer provided for an exemplary embodiment of this disclosure. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this disclosure clearer, the principles and spirit of this disclosure will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are provided merely to enable those skilled in the art to better understand and implement this disclosure, and are not intended to limit the scope of this disclosure in any way. Rather, these embodiments are provided to make this disclosure more thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0043] It is important to understand in this article that any number of elements in the accompanying figures is for illustrative purposes and not for limitation, and that any naming is for distinction only and has no limiting meaning.

[0044] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar words used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. The article "a" or "an" preceding an element does not exclude the existence of multiple such elements.

[0045] The principles and spirit of this disclosure will be explained in detail below with reference to several representative embodiments.

[0046] refer to Figure 1 This is a schematic diagram of a flexible display device in an unfolded state provided by an exemplary embodiment of the present disclosure.

[0047] The flexible display device 100 includes a flexible display panel 200 and a driving area 300. When the flexible display device 100 is in the unfolded state, the flexible display panel 200 is a single, straight plane.

[0048] refer to Figure 2 This is a schematic diagram of a flexible display device in a bent state provided by an exemplary embodiment of the present disclosure.

[0049] The flexible display device 100 includes a flexible display panel 200 and a driving area 300. The flexible display panel 200 includes a display panel bending area 202, a first display panel straight area 204 and a second display panel straight area 206. The display panel bending area 202 is located between the first display panel straight area 204 and the second display panel straight area 206, and connects the first display panel straight area 204 and the second display panel straight area 206.

[0050] The inventors of this disclosure have discovered that, due to the uneven heating of the flexible display panel 200, most of the heat is generated by the first straight plate area 204 of the display panel, which is close to the driving area 300. If the heat conduction capacity of the bending area 202 of the display panel is insufficient, it will lead to an excessive temperature difference between the first straight plate area 204 and the second straight plate area 206 of the display panel, which in turn leads to problems such as color difference and overall temperature rise.

[0051] refer to Figure 3 This is a schematic diagram of a flexible display panel provided in an exemplary embodiment of the present disclosure.

[0052] The flexible display panel 200 includes an overlapping support layer 210, an adhesive layer 220, a substrate (Panel) 230, a polarizing layer (POL) 240, and a protective layer 250.

[0053] The support layer 210 supports the entire module and can be made of high-strength metal materials such as stainless steel.

[0054] The inventors of this disclosure discovered that when the flexible display panel 200 is bent, the area on the support layer 210 corresponding to the bending area 202 of the display panel may experience distortion due to stress, which may worsen the creases in the flexible display panel 200 and affect its lifespan. Therefore, to reduce the rebound force of the support layer 210 when the flexible display panel 200 is bent, a slit structure is cut into the support layer 210 using a cutting device. The slit structures in adjacent rows are staggered, such as... Figure 4 As shown.

[0055] refer to Figure 4 This is a schematic diagram of a support layer provided in an exemplary embodiment of the present disclosure.

[0056] The support layer 210 includes a bending area 212, a first straight plate area 214 and a second straight plate area 216. The bending area 212 is located between the first straight plate area 214 and the second straight plate area 216 and connects the first straight plate area 214 and the second straight plate area 216.

[0057] It should be noted that the reference Figure 3 Since the support layer 210 is one of the layers of the flexible display panel 200, the bending area 212, the first straight plate area 214 and the second straight plate area 216 on the support layer 210 correspond one-to-one with the display panel bending area 202, the first straight plate area 204 and the second straight plate area 206 on the flexible display panel 200. Specifically, their orthographic projections completely overlap.

[0058] The bending area 212 is provided with multiple slit structures 218;

[0059] Multiple slit structures 218 are arranged in an array, with the row direction being the bending axis direction of the bending area 212. Adjacent rows of slit structures 218 are staggered, meaning there is an offset distance between them.

[0060] The inventors of this disclosure have discovered that the slit structure 218 increases the thermal resistance of the bending area 212, causing heat to accumulate in the first straight plate area 214 and increasing the temperature difference between the first straight plate area 214 and the second straight plate area 216 in the flexible display panel 200.

[0061] Specifically, the heat conduction Q of an object per unit time is as follows:

[0062]

[0063] Where λ is the thermal conductivity coefficient, A is the cross-sectional area perpendicular to the heat flow direction, dt / dx is the temperature gradient, L is the minimum distance for heat transfer, and dt / dx can also be expressed as the ratio of the temperature difference Δt between two points to the minimum heat transfer distance L between the two points; R is the thermal resistance, and from the above formula, the relationship of the thermal resistance R is:

[0064]

[0065] Therefore, when the slit structure 218 is added to the bending area 212, the cross-sectional area A perpendicular to the direction of heat flow will be significantly reduced, and the heat flow transmission distance L through the slit structure 218 will be increased, which will increase the thermal resistance R of the bending area 212, thereby increasing the temperature difference between the first straight plate area 214 and the second straight plate area 216 in the flexible display panel 200.

[0066] refer to Figure 5 As a specific example, this demonstrates the hindering effect of the slit structure 218 on the temperature conduction of the support layer 210.

[0067] The bending area 212 has a width of 10mm. 1.5W of heat power is applied to the first straight plate area 214. The bending area 212 hinders the temperature conduction between the first straight plate area 214 and the second straight plate area 216. The temperature difference between the first straight plate area 214 and the second straight plate area 216 can reach 33℃.

[0068] refer to Figure 6 This is a schematic diagram of the dimensions of a slit structure.

[0069] Where a and e are the long and short sides of the slit structure 218, respectively; b and f are the distances between the slit structure 218 in the row direction and the column direction, respectively; c and g are the array lengths of the long and short sides of the slit structure 218, respectively; the array length c of the long side of the slit structure 218 is defined as the sum of the long side a of the slit structure 218 and the distance b between the slit structure 218 in the row direction; the array length of the short side of the slit structure 218 is defined as the sum of the short side e of the slit structure 218 and the distance f between the slit structure 218 in the column direction; and d is the offset distance between two adjacent rows of slit structures 218.

[0070] The distances b and f between the slit structures 218 determine the cross-sectional area A perpendicular to the heat flow direction, while the offset distance d between two adjacent rows of slit structures 218 determines the heat flow transmission distance L through the slit structures 218. In conventional design:

[0071]

[0072] The inventors of this disclosure have discovered that, with other dimensions remaining unchanged, reducing the offset distance d between two adjacent rows of slit structures 218 can reduce L, decrease the thermal resistance R of the support layer 210 in the bending area, improve the heat transfer performance of the support layer 210, and thereby reduce the temperature difference between the first straight plate area 214 and the second straight plate area 216.

[0073] In this exemplary embodiment, the preset distance includes one-quarter of the sum of the length and spacing of the slit structure in the row direction.

[0074] In practice, when the offset distance d ≤ c / 4, the smaller d is, the more helpful it is to the heat conduction capability of the support layer 210, and the lower the temperature difference between the two ends of the bending area 212; when the offset distance d > c / 4, it has no effect on the heat conduction capability of the support layer 210.

[0075] refer to Figure 7 As a specific example, it demonstrates the hindering effect of the slit structure 218 with the improved offset distance on the temperature conduction of the support layer 210.

[0076] In other slit structures, the 218 dimensions are all the same. Figure 5Under the same conditions, when d is reduced from c / 2 to c / 20, the temperature distribution of the support layer 210 shows that, according to the simulation results, the temperature difference between the two sides of the bending region 212 decreases to 25℃.

[0077] refer to Figure 8 This is a schematic diagram of a support layer provided in an exemplary embodiment of the present disclosure.

[0078] In this exemplary embodiment, the slit structure 218 is offset alternately to the left and right in the column direction.

[0079] As a specific example, after the position of the first row of slit structures 218 is fixed, the second row of slit structures 218 is shifted to the left by d, the third row of slit structures 218 is shifted to the right by d, and so on...

[0080] refer to Figure 9 This is a schematic diagram of a support layer provided in an exemplary embodiment of the present disclosure.

[0081] In this exemplary embodiment, the slit structure 218 is offset along the first direction in the column direction.

[0082] As a specific example, after the position of the first row of slit structures 218 is fixed, the second row of slit structures 218 is shifted to the left by d, the third row of slit structures 218 is shifted to the left by d again, and so on...

[0083] refer to Figure 10 This is a schematic diagram of a support layer provided in an exemplary embodiment of the present disclosure.

[0084] In this exemplary embodiment, after the slit structure 218 is offset by a preset number of steps in the column direction along the first direction, it is offset by a preset number of steps in the column direction along the second direction.

[0085] The first direction and the second direction are opposite.

[0086] As a specific example, after the position of the first row of slit structures 218 is fixed, the second row of slit structures 218 is shifted to the right by d, the third row of slit structures 218 is shifted to the right by d again, and so on... The sixth row of slit structures 218 is shifted to the left by d, the seventh row of slit structures 218 is shifted to the left by d again, and so on... The tenth row of slit structures 218 is shifted to the right by d, the eleventh row of slit structures 218 is shifted to the right by d again, and so on... The fifteenth row of slit structures 218 is shifted to the left by d, the sixteenth row of slit structures 218 is shifted to the left by d again, and so on...

[0087] refer to Figure 11 This is a schematic diagram of a support layer provided in an exemplary embodiment of the present disclosure.

[0088] In this exemplary embodiment, when the slit structure 218 is offset in the column direction, the offset distance is different for different offsets.

[0089] As a specific example, after the position of the first row of slit structures 218 is fixed, the second row of slit structures 218 is shifted to the right by d1, the third row of slit structures 218 is shifted to the right by d2, the fourth row of slit structures 218 is shifted to the right by d3, the fifth row of slit structures 218 is shifted to the right by d4, and the sixth row of slit structures 218 is shifted to the right by d5.

[0090] The slit structure 218 in the seventh row is shifted to the right by d5; the slit structure 218 in the eighth row is shifted to the right by d4; the slit structure 218 in the ninth row is shifted to the right by d3; the slit structure 218 in the tenth row is shifted to the right by d2; and the slit structure 218 in the eleventh row is shifted to the right by d1.

[0091] The slit structure 218 in the twelfth row is shifted to the right by d1; the slit structure 218 in the thirteenth row is shifted to the right by d2; the slit structure 218 in the fourteenth row is shifted to the right by d3; the slit structure 218 in the fifteenth row is shifted to the right by d4; the slit structure 218 in the sixteenth row is shifted to the right by d5, and so on...

[0092] Among them, d2>d1, d3>d2, d4<d3, d5<d4.

[0093] refer to Figure 12 The support layer 210 slit structure 218 is manufactured by cutting, and the slit structure 218 is punched into a through hole by cutting equipment.

[0094] The inventors of this disclosure have discovered that when the slit structure 218 is punched into a through hole using a cutting device, heat cannot be transferred through the support layer 210 because the support layer 210 is not retained at the through hole, thus reducing the thermal conductivity of the support layer 210.

[0095] To further improve the thermal conductivity of the support layer 210, in this exemplary embodiment, the slit structure is obtained by etching the support layer, and the depth of the slit structure is less than the thickness of the support layer.

[0096] refer to Figure 13 and Figure 14 In a specific implementation, the support layer 210 involved in this exemplary embodiment uses an etching process to etch the slit structure 218 onto the support layer 210. The depth n of the slit structure 218 is less than the thickness of the support layer 210, leaving a portion of the thickness m of the slitless structure 218. The thickness region of the slitless structure 218 is close to the adhesive layer of the module to ensure the contact area with the adhesive layer and prevent air from appearing inside the module.

[0097] By pre-fabricating a screen with slit structure 218, screen printing technology is used to print corrosion-resistant ink or protective coating onto the support layer 210. Then, a UV exposure machine is used to expose the support layer 210 so that the slit structure 218 can be etched onto the support layer 210. During the etching process, the etching depth n is ensured to be less than the thickness of the support layer 210. At the same time, in order to reduce the rebound force and modulus of the support layer 210, the thickness m of the slit structure 218 should be as small as possible.

[0098] When a portion of the thickness m of the slitless structure 218 is retained, heat can be transferred from the thickness region of the slitless structure 218. This only reduces the cross-sectional area A perpendicular to the heat flow direction, while the heat flow transfer distance L will increase significantly. The thermal resistance R will be significantly reduced due to the influence of L, and the thermal conductivity of the support layer 210 will be improved.

[0099] refer to Figure 15 The temperature distribution of the support layer 210 for the semi-etched slit structure 218 is consistent with the temperature distribution of all slit structures 218. Figure 12 Under the same conditions, a semi-etching process was used, in which the slitless structure 218 was 30 μm thick. According to simulation results, the temperature difference on both sides of the bending area decreased to 12℃.

[0100] According to heat dissipation verification, when the thickness m of the slitless structure 218 is ≤ 60 μm, the larger the thickness m of the slitless structure 218, the stronger the thermal conductivity of the support layer 210 and the smaller the temperature difference between the two ends of the bending area 212. When the thickness m of the slitless structure 218 is > 60 μm, the thermal conductivity of the support layer 210 does not increase significantly with the increase of the thickness m of the slitless structure 218. At the same time, as the thickness m of the slitless structure 218 increases, the rebound force and modulus of the support layer 210 also increase significantly.

[0101] According to the above scheme, with the module architecture unchanged and the dimensions of other slit structures 218 in the support layer 210 unchanged, reducing the offset distance d between adjacent rows, when d≤c / 4, helps the heat conduction capability; using a semi-etching process to fabricate the slit structure 218, retaining a portion of the thickness of the slit-free structure 218, with the thickness m≤60μm of the slit-free structure 218, can reduce the thermal resistance of the support layer 210, increase the heat transfer performance of the support layer 210, and reduce the temperature difference between the highest temperature of the module and the display area.

[0102] As can be seen from the above description, the flexible display panel provided in this embodiment includes: a substrate; a display unit located on the substrate; and a support layer located on the side of the substrate away from the display unit. The support layer includes: a bending region; the bending region is provided with a plurality of slit structures; the plurality of slit structures are arranged in an array, wherein the row direction is the bending axis direction of the bending region, and there is an offset distance between adjacent rows of slit structures, wherein the offset distance is less than or equal to a preset distance.

[0103] This disclosure reduces the rebound force of the bending area of ​​the support layer when the flexible display panel is bent by setting a slit structure in the bending area of ​​the support layer;

[0104] By limiting the staggered distance between two adjacent rows of slit structures, the thermal resistance of the bending area is reduced, the heat transfer performance of the bending area is improved, and the temperature difference between different areas of the flexible display panel is reduced.

[0105] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0106] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0107] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

[0108] While the spirit and principles of this disclosure have been described with reference to several specific embodiments, it should be understood that this disclosure is not limited to the disclosed specific embodiments, and the division of aspects does not imply that features in these aspects cannot be combined for benefit; such division is merely for convenience of expression. This disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be interpreted in the broadest sense, thereby encompassing all such modifications and equivalent structures and functions.

Claims

1. A flexible display panel, characterized in that, include: Substrate; The display unit is located on the substrate. A support layer is located on the side of the substrate away from the display unit; The support layer includes: Bending area; The bending area is provided with multiple slit structures; Multiple slit structures are arranged in an array, wherein the row direction is the bending axis direction of the bending area, and there is an offset distance between adjacent rows of slit structures, wherein the offset distance is less than or equal to a preset distance, the preset distance including one-quarter of the sum of the length and spacing of the slit structures in the row direction.

2. The flexible display panel according to claim 1, characterized in that, The preset distance includes one-quarter of the sum of the length and spacing of the slit structure in the row direction.

3. The flexible display panel according to claim 1, characterized in that, The slit structure is offset alternately to the left and right in the column direction.

4. The flexible display panel according to claim 1, characterized in that, The slit structure is offset along a first direction in the column direction.

5. The flexible display panel according to claim 1, characterized in that, After the slit structure is offset by a preset number of steps in the column direction along the first direction, it is offset by a preset number of steps in the column direction along the second direction. The first direction and the second direction are opposite.

6. The flexible display panel according to claim 5, characterized in that, When the slit structure is offset in the column direction, the offset distance is different for different offsets.

7. The flexible display panel according to claim 1, characterized in that, The depth of the slit structure is less than the thickness of the support layer.

8. The flexible display panel according to claim 7, characterized in that, The difference between the depth of the slit structure and the thickness of the support layer is less than or equal to 60 μm.

9. The flexible display panel according to claim 1, characterized in that, The slit structure is obtained by etching the support layer.

10. A flexible display device, characterized in that, Includes the flexible display panel as described in any one of claims 1 to 9.

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