CN111933664A

CN111933664A - Flexible display panel

Info

Publication number: CN111933664A
Application number: CN202010776450.5A
Authority: CN
Inventors: 王鹏
Original assignee: Yungu Guan Technology Co Ltd
Current assignee: Yungu Guan Technology Co Ltd
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2020-11-13
Anticipated expiration: 2040-08-05
Also published as: CN111933664B

Abstract

The invention provides a flexible display panel, which comprises a light-emitting device layer, a plurality of sub-pixels and a plurality of pixel electrodes, wherein the light-emitting device layer comprises a plurality of sub-pixels; the shock resistance layer is arranged on the light emitting side of the light emitting device layer and comprises a stress buffering part and a plurality of stress dispersing parts; the stress buffer part is provided with a plurality of through holes, the number of the through holes is the same as that of the sub-pixels, and the projection of the through holes on the light-emitting device layer covers the sub-pixels; the stress dispersion part is filled in the through hole. By arranging the anti-impact layer, on one hand, the stress borne by the flexible display panel when being impacted can be effectively buffered by the stress buffering part, and on the other hand, the buffered stress can be timely dispersed by the stress dispersing part, so that the light-emitting device layer is effectively protected, and the problems of bright spots or colored spots caused by damage of the light-emitting device layer when the flexible display panel is impacted by external force are avoided.

Description

Flexible display panel

Technical Field

The invention relates to the technical field of display, in particular to a flexible display panel.

Background

An OLED (Organic light-emitting diode) display panel is widely popularized due to its advantages of low power consumption, high saturation, wide viewing angle, thin thickness, flexibility, and the like. With the maturity of the market and the advancement of the industry, the OLED display panel is gradually evolved from the conventional rectangular panel to the flexible display panel, for example: a circular watch, a vehicle-mounted display screen, etc. At present, the flexible OLED display panel still faces a plurality of technical challenges, and particularly, when the flexible OLED display panel is impacted by external force, stress borne by a stressed portion cannot be buffered and released, and the light emitting device is easily damaged when the flexible OLED display panel is impacted by the external force, so that the flexible OLED display panel has bright spots or color spots.

Disclosure of Invention

Based on this, it is necessary to provide a flexible OLED display panel, which includes:

a light emitting device layer including a plurality of sub-pixels;

the shock resistance layer is arranged on the light emitting side of the light emitting device layer and comprises a stress buffering part and a plurality of stress dispersing parts; the stress buffer part is provided with a plurality of through holes, the number of the through holes is the same as that of the sub-pixels, and the projection of the through holes on the light-emitting device layer covers the sub-pixels; the stress dispersion part is filled in the through hole.

In one embodiment, the stress buffering portion and the stress dispersing portion are the same thickness.

In one embodiment, the anti-impact layer further comprises a net-shaped supporting structure, the net-shaped supporting structure is composed of at least one hollowed-out polygonal frame connected with each other, the hollowed-out polygonal frame is arranged around the through hole, and the hollowed-out polygonal frame is a hollowed-out quadrilateral frame or a hollowed-out hexagonal frame.

In one embodiment, the young's modulus of the stress distributing portion is greater than the young's modulus of the stress buffering portion.

In one embodiment, the flexible display panel further includes a thin film encapsulation layer disposed on a surface of the impact resistant layer away from the light emitting device layer, and a thickness of the impact resistant layer is smaller than a thickness of the thin film encapsulation layer.

In one embodiment, the light emitting device layer further includes a plurality of pixel defining parts, the pixel defining parts have the same thickness and are arranged at intervals, and the sub-pixels are arranged between two adjacent pixel defining parts; the pixel definition parts are in direct contact with the surface of the stress buffer part close to one side of the light-emitting device layer.

In one embodiment, the opening area of the side of the through hole far away from the light-emitting device layer is larger than the opening area of the side of the through hole near the light-emitting device layer.

In one embodiment, the light transmittance of the stress dispersion portion is greater than the light transmittance of the stress buffering portion.

In one embodiment, the stress buffering portion is made of one or more of acrylic and epoxy materials.

In one embodiment, the material of the stress dispersion portion is one or more of polyurethane, polyacrylamide, and silicone rubber.

The flexible display panel provided by the invention comprises a light-emitting device layer, wherein the light-emitting device layer comprises a plurality of sub-pixels; the shock resistance layer is arranged on the light emitting side of the light emitting device layer and comprises a stress buffering part and a plurality of stress dispersing parts; the stress buffer part is provided with a plurality of through holes, the number of the through holes is the same as that of the sub-pixels, and the projection of the through holes on the light-emitting device layer covers the sub-pixels; the stress dispersion part is filled in the through hole. Through setting up the impact resistance layer, the stress that can make flexible display panel bear when receiving the impact on the one hand can obtain the buffering with the help of stress buffering portion effectively, and on the other hand can in time disperse with the help of the stress after the stress dispersion portion will cushion to protect the luminescent device layer effectively, avoid the luminescent device layer receive external force when strikeing impaired, lead to the appearance of bright spot or colored spot problem at flexible display panel.

Drawings

Fig. 1 is a schematic structural diagram of a flexible display panel according to an embodiment of the present invention;

fig. 2 is a top view of a flexible display panel structure according to an embodiment of the present invention;

fig. 3 is another top view of a flexible display panel structure according to an embodiment of the present invention;

fig. 4 is another schematic view of a flexible display panel structure according to an embodiment of the present invention;

fig. 5 is another schematic view of a flexible display panel structure according to an embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As described in the background, as the market matures and the industry advances, the OLED display panel is gradually changed from the conventional rectangular panel to the flexible display panel. The flexible OLED display panel still faces many technical challenges, and particularly, when the flexible OLED display panel is impacted by external force, stress borne by a stressed portion cannot be buffered and released, and the light emitting device is easily damaged when the flexible OLED display panel is impacted by external force, so that the flexible OLED display panel has bright spots or color spots. To this end, an embodiment of the present invention provides a flexible display panel, as shown in fig. 1 to 3, including: a light emitting device layer 100, the light emitting device layer 100 including a plurality of sub-pixels 101; the anti-impact layer 200 is arranged on the light emitting side of the light emitting device layer 100, and the anti-impact layer 200 comprises a stress buffering part 201 and a plurality of stress dispersing parts 202; the stress buffer part 201 is provided with a plurality of through holes, the number of the through holes is the same as that of the sub-pixels 101, and the projection of the through holes on the light-emitting device layer 100 covers the sub-pixels 101; at the same time, the stress dispersion portion 202 is filled in the through hole.

It can be understood that the entire surface of the impact resistant layer 200 covers the light emitting device layer 100, and when an external impact such as dropping of the flexible display panel or falling of the flexible display panel occurs, the impact resistant layer 200 can protect the light emitting device layer 100 and prevent the sub-pixels 101 in the light emitting device layer 100 from being damaged due to the external impact. Specifically, the impact resistant layer 200 includes a stress buffering portion 201 and a plurality of stress dispersing portions 202, wherein the stress buffering portion 201 is usually made of an organic material with a hardness greater than that of the light emitting material, so that when external force impact occurs, most of stress can be resisted or offset for the light emitting device layer 100, and thus, a buffering protection effect on the sub-pixel 101 is achieved; however, in most cases, the region or position where the external force impacts the flexible display panel is random and not fixed, so the display panel provided by the present invention further has a plurality of through holes in the stress buffering portion 201, each through hole corresponds to one of the sub-pixels 101 in the light emitting device layer 100, and the through holes are used for disposing the stress dispersing portions 202, in other words, the stress dispersing portions 202 are disposed in the through holes in a filling manner; by arranging the stress dispersion part 202, the stress formed by the impact resistance layer 200 impacted by the external force can be effectively dispersed to the whole surface of the impact resistance layer, so that the original stress point is stressed and dispersed and converted into the stress of the stressed surface, the influence of the stress on the light-emitting device layer 100 is reduced to the greatest extent, and the problem of stress concentration of the impact resistance layer 200 is solved.

Specifically, the projection of the through hole on the light emitting device layer 100 covers the sub-pixel 101, which means that even when an external force directly impacts the stress dispersing portion 202, the stress is dispersed to the adjacent stress buffering portion 201, the stress buffering portion 201 buffers and absorbs the stress transmitted by the stress dispersing portion 202, and the stress is dispersed to the whole surface of the impact resistant layer 200 through the stress dispersing portion 202 adjacent to the stress buffering portion 201, so that the light emitting device layer 100 can be protected to the maximum extent, and the same protection effect as that when the external force impacts the stress buffering portion 201 can be achieved, so that the protection of the sub-pixel 101 is effectively achieved, and the sub-pixel 101 is prevented from being damaged due to the fact that the sub-pixel 101 directly bears the stress.

In order to ensure the buffer protection effect of the impact resistant layer 200, to timely buffer and disperse the stress, and to ensure that the stress can be timely dispersed while the stress buffer layer 201 buffers or withstands most of the stress from the external force, as one embodiment of the present invention, the thicknesses of the stress buffer portion 201 and the stress dispersion portion 202 are the same.

It can be understood that the stress buffering portion 201 can be formed by a chemical vapor deposition process, a mask is set on the surface of the stress buffering portion 201, a through hole corresponding to the sub-pixel position is etched, and then the stress dispersing portion 202 is formed by the chemical vapor deposition process.

Alternatively, the thickness of the stress buffering portion 201 and the thickness of the stress dispersing portion 202 are both 8 to 12 μm.

As shown in fig. 2-3, the impact-resistant layer 200 further includes a net-shaped supporting structure, which is composed of at least one hollow-out polygonal frame connected to each other, in this embodiment, the hollow-out polygonal frame may be a hollow-out quadrangular frame 302 or a hollow-out hexagonal frame 301.

Further, the hollow hexagonal frame 301 and/or the hollow quadrangular frame 302 are disposed around the through hole.

It can be understood that, the hollowed-out hexagonal frame 301 and the hollowed-out quadrangular frame can be etched and removed in a mode of adding a mask plate in a process of preparing the stress buffering part 201 after the process of forming the stress buffering part 201 is completed, so that a hexagon or a quadrangle corresponding to an area needing to be hollowed out is etched and removed, and accordingly the edge is kept to form a hollowed-out polygonal frame structure.

In one embodiment of the present invention, as shown in fig. 2, in the impact-resistant layer 200, the mesh-shaped supporting structure is composed of a plurality of hollowed-out hexagonal frames 301 and a plurality of hollowed-out quadrangular frames 302, wherein the common edge of the plurality of hollowed-out hexagonal frames 301 and the plurality of hollowed-out quadrangular frames 302 forms a frame structure surrounding the through hole.

Specifically, the mesh-shaped supporting structure including at least one hollow polygonal frame connected to each other is disposed on the anti-impact layer 200, so as to further improve the buffering and stress-dispersing effects of the anti-impact layer 200. It should be noted that the net-shaped supporting structure is formed by etching the stress buffering portion 201, and thus does not change its physical properties, and therefore has the same elastic modulus as the stress buffering portion 201. When the impact resistance layer 200 is impacted by external force, the net-shaped supporting structure can effectively improve the buffering capacity of the stress buffering part 201, and the resilience capacity of the stress buffering part 201 is improved by utilizing the supporting characteristic of the net-shaped structure on the basis, so that when the stress is generated, the net-shaped supporting structure can better counteract most of the stress on one hand and provide enough protection for the light emitting device layer 100, and on the other hand, the net-shaped supporting structure can transmit the longitudinal stress to the transverse direction when the vertical load hits the impact resistance layer 200, so that the stress is dispersed to the whole surface of the impact resistance layer 200 through the stress dispersing part 202, and the capacity of the flexible display panel for resisting the external force is improved.

In another embodiment of the present invention, as shown in fig. 3, in the impact-resistant layer 200, the net-shaped supporting structure may be composed of only a plurality of hollowed hexagonal frames 301, wherein edges of the plurality of hollowed hexagonal frames 301 form a frame structure surrounding the through hole; in a preferred embodiment, the interface of the hollowed-out hexagonal frame 301 is in the shape of a regular hexagon. Through the design, the reticular support structure formed by the hollow hexagonal frameworks 301 can present a honeycomb-like structure form: on one hand, the hexagons have symmetry, and meanwhile, as the hexagons can be connected in the most polygonal number as a single figure, compared with the triangles and quadrilaterals with the same area, the perimeter of the hexagons is smaller, so that the design of the reticular supporting structure into a plurality of hollowed-out hexagonal frames 301 can ensure that the edges of the reticular supporting structure can bear larger stress compared with the hollowed-out quadrilateral frames 302; on the other hand, hexagons may better distribute laterally transmitted stresses than other polygons. Therefore, the net-shaped supporting structure is designed into a honeycomb-like structure formed by a plurality of hollowed hexagonal frames 301, and the capability of the flexible display panel for resisting external force is improved to the greatest extent by means of the characteristics of strong bearing capacity and stable structure of the honeycomb-like structure.

It is understood that the impact resistant layer 200 may further include a mesh groove structure (not shown in the drawings) corresponding to the mesh support structure. Specifically, in the process of preparing the stress buffering portion 201, after the process of forming the stress buffering portion 201 is completed, a hexagonal or quadrangular etching corresponding to an area to be hollowed out is covered and retained by adding a mask plate, and then the edge is etched and removed to form a plurality of hollowed-out groove structures and a plurality of polygonal areas. In the embodiment of the present invention, the plurality of mesh-shaped groove structures and the plurality of polygonal regions may form a mesh-shaped structure corresponding to the mesh-shaped support structure, and when an external force impact occurs, a vertical load formed by a stress may be transmitted from a longitudinal direction to a lateral interface through the mesh-shaped groove structures, so that the external force applied to the force-bearing point of the impact-resistant layer 200 is dispersed to the entire surface through the stress dispersion portion 202.

Further, in order to further enhance the cushioning and protecting effects of the impact resistance layer 200 on the light emitting device layer 100, the young's modulus of the stress dispersion portion 202 may be designed to be greater than that of the stress buffering portion 201, so that the stress dispersion portion 202 may better provide protection for the sub-pixel 101.

As shown in fig. 4, the flexible display panel further includes a thin film encapsulation layer 400, the thin film encapsulation layer 400 is disposed on a surface of the impact resistance layer 200 away from the light emitting device layer 100, and a thickness of the impact resistance layer 200 is smaller than a thickness of the thin film encapsulation layer 400. Specifically, the film encapsulation layer 400 is formed by alternately distributing organic film layers and inorganic film layers, the topmost film layer in the film encapsulation layer 400 is an inorganic film layer, and at least part of the inorganic film layers except the topmost layer can adopt a sectional structure; the inorganic film layer can be made of one or more of silicon oxide (SiO2), silicon nitride (SiN), aluminum oxide (Al2O3) and titanium oxide (TiO2), and the organic film layer can be made of one or more of epoxy, phenolic, polyester or organic silicon organic matters. It will be appreciated that, depending on material mechanics, there is a neutral layer of zero both normal and shear stress in any of the bent objects, the location of the neutral layer being largely dependent on the thickness of the bent object, so the thickness of the impact resistant layer 200 is set to be less than the thickness of the thin film encapsulation layer 400, the neutral layer of the flexible display panel may be moved toward the thin film encapsulation layer 400 side, and thus when the panel is damaged or subjected to more concentrated stress beyond the bending radius, while the impact resistant layer 200 provides protection for the light emitting device layer 100, the neutral layer is moved to one side of the thin film packaging layer 400, so that the integrity and the bending resistance of the thin film packaging layer 400 can be effectively guaranteed, and the situation that the reliability and the display effect of the light emitting device layer 100 are influenced by packaging failure, water vapor and oxygen invasion of the light emitting device layer 100 caused by breakage of the thin film packaging layer 400 in the process is avoided.

Optionally, the thin film encapsulation layer 400 has a thickness of 12 μm to 40 μm.

As shown in fig. 1 to fig. 5, in the flexible display panel provided in the present invention, the light emitting device layer 100 further includes a plurality of pixel defining portions 102, the plurality of pixel defining portions 102 have the same thickness and are disposed at intervals, and the sub-pixel 101 is disposed between two adjacent pixel defining portions 102; the pixel defining parts 102 are in direct contact with the surface of the stress buffering part 201 close to the light emitting device layer 100, so that the buffering protection effect of the impact resistance layer 200 is better ensured.

As shown in fig. 5, in one embodiment of the present invention, the opening area of the side of the via hole away from the light emitting device layer 100 is larger than the opening area of the side of the via hole close to the light emitting device layer 100. The design is to design the cross section of the through hole to be an inverted trapezoid, that is, the opening area of the through hole on the side far away from the light-emitting device layer 100 is larger than the opening area of the through hole on the side near the light-emitting device layer 100, so that the light path originally shielded by the through hole can be more completely scattered, the light-emitting effect of the light-emitting device layer 100 is effectively ensured, and the display effect of the flexible display panel is fully ensured.

Further, in the flexible display panel provided by the present invention, in order to ensure a better display effect, the light transmittance of the stress dispersion portion 202 is designed to be greater than that of the stress buffering portion 201.

Optionally, in the flexible display panel provided by the invention, the material of the stress buffering portion 201 is one or more of acrylic acid and epoxy material; the material of the stress dispersion part is one or more of polyurethane, polyacrylamide and silicon rubber.

In summary, according to the technical scheme of the invention, the anti-impact layer 200 is disposed on the light emitting side of the light emitting device layer 100, so as to improve the reliability of the flexible display panel: on one hand, the stress borne by the flexible display panel when being impacted can be effectively buffered by the stress buffering part 201, and on the other hand, the buffered stress can be timely dispersed by the stress dispersing part 202 so as to effectively protect the light-emitting device layer 100; the problems that when the flexible display panel is impacted by external force, stress borne by a stressed part cannot be buffered and released, and the flexible display panel is easily damaged by the light-emitting device when the flexible display panel is impacted by the external force, so that bright spots or colored spots appear on the flexible display panel are effectively solved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A flexible display panel, comprising:

a light emitting device layer including a plurality of sub-pixels;

the shock resistance layer is arranged on the light emitting side of the light emitting device layer and comprises a stress buffering part and a plurality of stress dispersing parts; the stress buffering part is provided with a plurality of through holes, the number of the through holes is the same as that of the sub-pixels, and the projection of the through holes on the light-emitting device layer covers the sub-pixels; the stress dispersion part is filled in the through hole.

2. The flexible display panel according to claim 1, wherein the stress buffering portion and the stress dispersing portion are the same thickness.

3. The flexible display panel according to claim 1, wherein the impact resistant layer further comprises a mesh support structure, the mesh support structure is formed by at least one hollow polygonal frame connected to each other, the hollow polygonal frame is disposed around the through hole, and the hollow polygonal frame is a hollow quadrilateral frame or a hollow hexagonal frame.

4. The flexible display panel according to claim 1, wherein a young's modulus of the stress dispersing portion is larger than a young's modulus of the stress buffering portion.

5. The flexible display panel of claim 1, further comprising a thin film encapsulation layer disposed on a surface of the impact resistant layer on a side away from the light emitting device layer, wherein a thickness of the impact resistant layer is less than a thickness of the thin film encapsulation layer.

6. The flexible display panel according to claim 1, wherein the light emitting device layer further comprises a plurality of pixel defining portions, the plurality of pixel defining portions have the same thickness and are spaced apart from each other, and the sub-pixels are disposed between two adjacent pixel defining portions; and a plurality of pixel defining parts are in direct contact with the surface of one side of the stress buffering part close to the light-emitting device layer.

7. The flexible display panel of claim 1, wherein an open area of the via on a side away from the light emitting device layer is larger than an open area of the via on a side close to the light emitting device layer.

8. The flexible display panel of claim 1, wherein a light transmittance of the stress dispersing portion is greater than a light transmittance of the stress buffering portion.

9. The flexible display panel according to claim 1, wherein the stress buffering portion is made of one or more of acrylic and epoxy materials.

10. The flexible display panel according to claim 1, wherein the stress dispersion unit is made of one or more of polyurethane, polyacrylamide, and silicone rubber.