Display panel and display device
By using conductive foldable metamaterials to construct the cathode layer and auxiliary anode layer in OLED screens, brightness self-compensation is achieved, solving the problems of uneven brightness and shortened lifespan in OLED screens during folding, and improving display uniformity and lifespan.
Patent Information
- Application Number
- CN202610691855.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-19
- Publication Date
- 2026-06-16
AI Technical Summary
During the folding process, the top cathode and bottom anode of an OLED screen are subjected to different forces, which causes changes in the contact state between the light-emitting layer and the cathode and anode, resulting in uneven brightness in the light-emitting area and a shortened lifespan.
The cathode layer and auxiliary anode layer are constructed using conductive folded metamaterials. This reduces the resistance of the cathode layer when stretched and increases the resistance of the auxiliary anode layer when compressed. By connecting them in parallel, brightness self-compensation and coordinated regulation of current distribution are achieved.
It effectively improves the display uniformity of foldable screens in a bent state, extends the lifespan of components, avoids local brightness differences and current surges, and improves the stability of the light-emitting layer.
Smart Images
Figure CN122227801A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of displays, and more particularly to a display panel and display device. Background Technology
[0002] Organic light-emitting diodes (OLEDs) possess advantages such as surface light source, energy saving, fast response, high flexibility, ultra-thinness, and low cost, and their mass production technology is becoming increasingly mature. Currently, foldable screen phones have become a popular trend, and OLED screens generally bend inwards. When the screen bends inwards, the top electrode (cathode) of the OLED screen is subjected to tensile force, while the bottom electrode (anode) is subjected to compressive force. These two different types of forces act simultaneously on the screen structure, posing a significant challenge to the device's mechanical stability. Especially for pixels located at the folding position in a foldable screen, screen folding causes changes in the contact state between the light-emitting layer and the cathode and anode, leading to unexpected changes in the light-emitting area and brightness. If this is not effectively adjusted and improved, it will accelerate the performance degradation of the light-emitting layer and shorten the device's lifespan. Summary of the Invention
[0003] This application provides a display panel and display device that can achieve brightness self-compensation of the foldable screen in the bent state, effectively improving display uniformity and extending the service life of the device.
[0004] In a first aspect, this application provides a display panel, including: substrate; A pixel definition layer protrudes from one side of the substrate and forms a plurality of spaced pixel receiving areas; An anode structure is disposed within the pixel accommodating area, including a main anode layer and an auxiliary anode layer connected in parallel with the main anode layer, wherein the auxiliary anode layer is disposed on the side of the main anode layer facing the substrate; An organic light-emitting functional layer is disposed within the pixel accommodating area and covers the main anode layer; A cathode layer covers the side of the pixel definition layer opposite to the substrate, and the side of the organic light-emitting functional layer opposite to the substrate; When the display panel is bent, the auxiliary anode layer is compressed and its resistance increases, while the cathode layer is stretched and its resistance decreases.
[0005] In some embodiments, both the auxiliary anode layer and the cathode layer are formed of a conductive folded metamaterial; wherein the conductive folded metamaterial exhibits increased resistance when compressed and decreased resistance when stretched.
[0006] In some embodiments, the pixel definition layer includes a plurality of spaced-apart opening regions and a non-opening region located between two adjacent opening regions, the opening regions forming the pixel accommodating area; On a plane perpendicular to the height direction, the projection of the main anode layer covers the projection of the opening area, and the projection of the auxiliary anode layer covers the projection of the opening area; In the length direction, both ends of the main anode layer extend below the non-opening region, and both ends of the auxiliary anode layer extend into the interior of the non-opening region, with the ends of the auxiliary anode layer respectively extending beyond the ends of the main anode layer.
[0007] In some embodiments, the auxiliary anode layer includes: The main body segment is stacked with the main anode layer; The reinforcing segments are respectively disposed at both ends of the main body segment in the length direction and extend into the interior of the non-opening area; the reinforcing segments include multiple convex segments and multiple concave segments arranged alternately.
[0008] In some embodiments, the cathode layer includes: The first cathode portion covers the side of the organic light-emitting functional layer that is away from the substrate; The second cathode portion covers the side of the non-opening area away from the substrate; in the height direction, the distance between the second cathode portion and the substrate is greater than the distance between the first cathode portion and the substrate; The third cathode portion is connected to the first cathode portion and the second cathode portion at both ends, and the third cathode portion covers the organic light-emitting functional layer.
[0009] In some embodiments, the display panel further includes: A first encapsulation layer is disposed on the side of the first cathode portion facing away from the substrate; in the length direction, there are gaps between both ends of the first encapsulation layer and the non-opening area, and the third cathode portion is located within the gaps; The second encapsulation layer is disposed on the side of the second cathode portion away from the substrate and on the side of the first encapsulation layer away from the substrate, and spans across the gap.
[0010] In some embodiments, when the display panel is bent, the third cathode portion is stretched, and the contact area between the third cathode portion and the organic light-emitting functional layer is reduced.
[0011] In some embodiments, the third cathode portion is obliquely connected to the first cathode portion and the second cathode portion, and the third cathode portion has an oblique angle with the height direction; When the display panel is bent, the third cathode portion is stretched, the tilt angle increases, and the contact area between the third cathode portion and the organic light-emitting functional layer decreases.
[0012] In some embodiments, the main anode layer is formed of a metallic material.
[0013] Secondly, this application provides a display device, including the display panel as described above.
[0014] The technical solutions provided in this application have the following advantages compared with the prior art: The display panel provided in this application embodiment achieves brightness self-compensation in the bending state of the folding screen by constructing the cathode layer to reduce resistance when stretched, constructing the auxiliary anode layer to increase resistance when compressed, and connecting the auxiliary anode layer and the main anode layer in parallel, which effectively improves the display uniformity and extends the service life of the device. Specifically, when the display panel is folded inward, the cathode layer at the top is stretched. Since the cathode layer is designed to reduce its resistance when stretched, the resistance of the cathode layer in the folded area also decreases, thereby effectively compensating for the current drop caused by the reduction in the contact area between the cathode layer and the organic light-emitting functional layer. This allows the current in the cathode layer to be maintained, avoiding the local darkening problem in the folded area caused by stretching in existing display panels. It also prevents local overload caused by the driving circuit increasing the current in other areas due to a significant drop in the cathode-side current, and reduces the current surge in the light-emitting layer. Meanwhile, the auxiliary anode layer at the bottom is compressed during folding. Because the auxiliary anode layer is designed to increase its resistance under compression, and it is connected in parallel with the main anode layer, this increased resistance directly leads to an increase in the total parallel resistance, thereby reducing the current injected into the organic light-emitting functional layer. This active current reduction mechanism effectively avoids the localized brightness enhancement problem caused by compression on the compressed side in existing display panels, prevents the risk of accelerated aging of the light-emitting layer due to excessive current density, and keeps the brightness of the pixels on the compressed side consistent with that of the uncompressed areas. Through the synergistic effect of the cathode layer and the auxiliary anode layer—that is, by reducing the holding current on the cathode side through lower resistance and reducing the current on the anode side through higher resistance—automatic balance of pixel brightness is achieved under bending conditions. This significantly improves the display uniformity of the folded area, avoids additional adjustments to the driving circuit due to brightness differences, and ensures that the light-emitting layer experiences a uniform current density throughout the entire display area. This reduces local stress concentration and current surges, effectively slowing down the performance degradation rate of the light-emitting layer and extending its lifespan. Furthermore, the direct contact between the main anode layer and the organic light-emitting functional layer forms a stable hole injection interface. Attached Figure Description
[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.
[0018] Figure 1 This is a schematic diagram of the structure of the display panel provided in an embodiment of this application; Figure 2 A schematic diagram of the structure of pixels in the folded area of the display panel when it is not bent, as provided in an embodiment of this application. Figure 3 A schematic diagram of the structure of pixels in the folded area of a display panel when bent, as provided in an embodiment of this application. Figure 4 This is a schematic diagram of the structure of the conductive folded metamaterial provided in the embodiments of this application; Figure 5 This is an enlarged schematic diagram of the conductive folded metamaterial provided in the embodiments of this application.
[0019] Explanation of reference numerals in the attached figures: 10. Substrate; 20. Pixel definition layer; 210. Non-aperture area; 30. Anode structure; 310. Main anode layer; 320. Auxiliary anode layer; 3201. Main body section; 3202. Reinforcing section; 3203. Convex upper section; 3204. Concave lower section; 40. Organic light-emitting functional layer; 50. Cathode layer; 510. First cathode section; 520. Second cathode section; 530. Third cathode section; 60. First encapsulation layer; 70. Second encapsulation layer; 80. Gap. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.
[0022] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include the orientation of being below. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.
[0023] Organic light-emitting diodes (OLEDs) have been widely used in the display field due to their advantages such as surface light source, energy saving, fast response speed, good flexibility, ultra-thinness, and low cost, and their mass production technology is becoming increasingly mature. Typically, the light-emitting layer of an OLED consists of three light-emitting thin films of red, green, and blue colors. In the preparation of these three color light-emitting thin films, it is often necessary to use a printing patterning process with grids (isolation pillars) on the substrate.
[0024] With the development of flexible display technology, foldable screen phones are gradually becoming the mainstream in the market. The folding performance of a flexible screen is closely related to its layered structure. Generally speaking, the layered structure of an OLED screen includes a polarizer, a panel layer, etc., and the layers are bonded together as a whole using optically transparent adhesive. Currently, the bending method of the screen is mainly inward bending.
[0025] When the screen bends inward, the top electrode (cathode) is subjected to tensile force, while the bottom electrode (anode) is subjected to compressive force. The interaction of these two different types of forces significantly impacts the upper and lower structures of the screen, making the structural stability of foldable screens a critical technical issue. Particularly for pixels located at the folded position, when the screen folds, the cathode's contact area with the light-emitting layer shrinks due to stretching, leading to a decrease in electron flow injected into the light-emitting layer and a drop in localized brightness. Conversely, the anode's compression increases the hole current injected into the light-emitting layer, causing a localized increase in brightness. This unintended change in brightness in the light-emitting area disrupts display uniformity. Without effective adjustment and improvement, this will accelerate the performance degradation of the light-emitting layer and reduce the lifespan of the device.
[0026] In response to the above technical problems, such as Figure 1 As shown, this application embodiment provides a display panel including a substrate 10, a pixel definition layer 20, an anode structure 30, an organic light-emitting functional layer 40, and a cathode layer 50. The pixel definition layer 20 protrudes from one side of the substrate 10 and forms a plurality of spaced pixel receiving areas. The anode structure 30 is disposed in the pixel receiving area and includes a main anode layer 310 and an auxiliary anode layer 320 connected in parallel with the main anode layer 310. The auxiliary anode layer 320 is disposed on the side of the main anode layer 310 facing the substrate 10. The organic light-emitting functional layer 40 is disposed in the pixel receiving area and covers the main anode layer 310. The cathode layer 50 covers the side of the pixel definition layer 20 away from the substrate 10 and the side of the organic light-emitting functional layer 40 away from the substrate 10. When the display panel is bent, the auxiliary anode layer 320 is compressed and its resistance increases, while the cathode layer 50 is stretched and its resistance decreases.
[0027] As can be seen from the above, by constructing the cathode layer 50 to reduce resistance when stretched, constructing the auxiliary anode layer 320 to increase resistance when compressed, and connecting the auxiliary anode layer 320 in parallel with the main anode layer 310, the brightness self-compensation of the foldable screen in the bending state is realized, which effectively improves the display uniformity and extends the service life of the device. Specifically, when the display panel is folded inward, the cathode layer 50 at the top is stretched. Since the cathode layer 50 is configured to reduce its resistance when stretched, the resistance of the cathode layer 50 in the folded area also decreases, thereby effectively compensating for the current drop caused by the reduction in the contact area between the cathode layer 50 and the organic light-emitting functional layer 40. This allows the current of the cathode layer 50 to be maintained, avoiding the problem of local darkening in the folded area caused by stretching in existing display panels. It also prevents local overload caused by the driving circuit increasing the current in other areas due to a significant drop in the cathode-side current, and reduces the current surge in the light-emitting layer. Meanwhile, the auxiliary anode layer 320 at the bottom is compressed during folding. Since the auxiliary anode layer 320 is configured to increase its resistance when compressed, and it is connected in parallel with the main anode layer 310, the increased resistance of the auxiliary anode layer 320 directly leads to an increase in the total parallel resistance, thereby reducing the current injected into the organic light-emitting functional layer 40. This active current reduction mechanism effectively avoids the problem of localized brightness enhancement caused by compression on the compressed side in existing display panels, prevents the risk of accelerated aging of the light-emitting layer due to excessive current density, and keeps the brightness of the pixels on the compressed side consistent with that of the uncompressed area. Through the synergistic effect of the cathode layer 50 and the auxiliary anode layer 320—that is, by reducing the current on the cathode side through lower resistance and reducing the current on the anode side through higher resistance—automatic balance of pixel brightness is achieved under bending conditions. This significantly improves the display uniformity of the folded area, avoids additional adjustments to the driving circuit due to brightness differences, and ensures that the light-emitting layer experiences a uniform current density throughout the entire display area. This reduces local stress concentration and current surges, effectively slowing down the performance degradation rate of the light-emitting layer and extending its lifespan. Furthermore, the direct contact between the main anode layer 310 and the organic light-emitting functional layer 40 forms a stable hole injection interface.
[0028] It should be noted that, in this application, "display panel bending" refers to the display panel being folded inwards, that is, the light-emitting surface of the display panel is folded inwards, so that the opposite sides of the panel are brought closer together. At this time, the cathode layer 50 located at the top of the display panel is in a stretched state, and the anode structure 30 located at the bottom of the display panel is in a compressed state. For ease of description, the following embodiments will use this inward bending state as a reference state for the bending of the display panel.
[0029] It should also be noted that the display panel structure used in this application can be flexibly configured according to actual application requirements. Specifically, the display panel including the main anode layer 310, auxiliary anode layer 320, cathode layer 50 and related structures can be disposed only in the folded area of the display panel to specifically improve the display uniformity and bending reliability of the folded area; or it can be extended to the non-folded area of the display panel. Regardless of the above configuration, the display panel can achieve brightness self-compensation and active adjustment of the light-emitting area in the bent state through the opposite resistance change characteristics of the cathode layer 50 and the auxiliary anode layer 320, thereby effectively improving display uniformity and extending the device lifespan.
[0030] In some embodiments, both the auxiliary anode layer 320 and the cathode layer 50 are formed of a conductive folded metamaterial; wherein the conductive folded metamaterial exhibits increased resistance when compressed and decreased resistance when stretched.
[0031] By setting both the auxiliary anode layer 320 and the cathode layer 50 to be formed of conductive folded metamaterial, and making the material increase in resistance when compressed and decrease in resistance when stretched, bidirectional electrical adjustment of the foldable screen in the bending state is realized, thereby effectively improving display uniformity and extending device lifespan. Specifically, when the display panel is folded inwards, the top cathode layer 50 is stretched. Since the cathode layer 50 is formed of a conductive folded metamaterial, its resistance decreases under stretching, effectively compensating for the current drop caused by the reduced contact area between the cathode layer 50 and the organic light-emitting functional layer 40. This maintains the current in the cathode layer 50 and avoids localized darkening in the folded area due to stretching. Simultaneously, the bottom auxiliary anode layer 320 is compressed during folding. Since the auxiliary anode layer 320 is also formed of a conductive folded metamaterial, its resistance increases under compression. Furthermore, the auxiliary anode layer 320 is connected in parallel with the main anode layer 310. The increased resistance of the auxiliary anode layer 320 directly increases the total parallel resistance, thereby reducing the current injected into the organic light-emitting functional layer 40. This active current reduction mechanism effectively avoids localized brightness enhancement caused by compression on the compressed side, maintaining harmony between the brightness of the compressed pixels and the uncompressed areas.
[0032] It is important to note that conductive folded metamaterials (CFMs) are a new type of metamaterial that possesses high conductivity and excellent mechanical folding durability through artificial structural design. Their core characteristics stem from their intricately designed microstructure, rather than the material's inherent chemical composition. Traditional intrinsically conductive materials (such as metals, conductive polymers, and carbon nanotubes) rely on chemical bonds to transfer stress, making them unable to withstand repeated 180° "true folds" (i.e., the two sides are completely flush at the fold), and stress accumulation can easily lead to fracture or performance degradation. In contrast, CFMs, through specific microstructural designs, can maintain excellent conductivity while withstanding numerous or even unlimited damage-free folds. CFMs can be prepared using various processes. For example... Figure 4 , Figure 5 As shown, in some embodiments, a low-power laser is coupled with a biomimetic Taylor cone process in a high-voltage electrostatic field using a "laser-electrostatic field coupled biomimetic spinning" technique. This allows for precise control of the flight assembly parameters of the carbon nanotube precursor solution, resulting in polymer composite fibers. After carbonization, conductive folded metamaterials are obtained; the conductivity of this material can reach 10³ S·m. - ¹ magnitude, and can withstand 10 7 The material undergoes multiple, even infinite, lossless folding processes. During the folding process, an "ε"-like structure is formed inside the material, consisting of a wave-like protrusion layer, localized fiber slip grooves, and stress dispersion arcs. This structure effectively disperses the stress generated by the 180° folding in multiple dimensions, including lines, surfaces, and volumes, preventing chemical bonds from directly bearing extreme stress and thus protecting the integrity of the conductive nanofibers. CFMs possess unique electrical properties. Under tensile strains of 0–50% or even higher, their electrical resistance decreases significantly with increasing tension, and recovers reversibly upon release. The microscopic mechanism behind this property lies in the controllable topological reconstruction of the conductive network within the CFMs, rather than a simple "stretching." Specifically, the conductive network of CFMs exhibits a three-dimensional porous, wrinkled, or interlocked structure, undergoing the following changes upon stretching: (1) The contact resistance drops significantly. In the initial state, the conductive nanounits that make up CFMs (such as carbon nanotubes, MXene, graphene, etc.) are in point contact or weak contact, and the contact resistance is relatively large. After stretching, the units are straightened and compressed, and they are transformed into surface contact or strong contact. The contact area increases exponentially, thereby causing the contact resistance to drop sharply. (2) The conductive path is "straightened" and the bulk resistance decreases. In the initial state, the conductive network is bent and entangled, the carrier transport path is long and there is a lot of scattering; after stretching, the path is straightened, the carrier path becomes shorter and the bulk resistance decreases; (3) The porous structure is densified, and the conductive network is more continuous. In the initial state, there are a lot of air gaps in the porous structure, and the conductive path is discontinuous; after stretching, the pores are compressed and closed, the conductive network is more dense, and the overall conductivity is improved; CFMs offer diverse material systems, allowing selection based on specific application requirements. Mainstream materials include MXene (two-dimensional transition metal carbides, nitrides, or carbonitrides)-based CFMs, carbon nanotube or graphene-based CFMs, and composite structures of metal nanowires or nanomesh with CFMs. The specific structures, properties, and preparation methods of CFMs are existing technologies and will not be elaborated upon in this application.
[0033] It should also be noted that the film formation method of conductive folded metamaterials can be selected according to specific process requirements, including but not limited to biomimetic electrospinning, solution method, vacuum filtration and transfer, laser direct writing or laser induction and other methods.
[0034] In some embodiments, the pixel definition layer 20 includes a plurality of spaced-apart opening regions and a non-opening region 210 located between two adjacent opening regions, the opening regions forming a pixel accommodating region. On a plane perpendicular to the height direction, the projection of the main anode layer 310 covers the projection of the opening area, and the projection of the auxiliary anode layer 320 covers the projection of the opening area. In the length direction, the two ends of the main anode layer 310 extend below the non-opening region 210, the two ends of the auxiliary anode layer 320 extend into the interior of the non-opening region 210, and the two ends of the auxiliary anode layer 320 extend beyond the two ends of the main anode layer 310 respectively.
[0035] By ensuring that the projections of the main anode layer 310 and the auxiliary anode layer 320 both cover the projection of the opening area in a direction perpendicular to the substrate 10, and by setting the two ends of the main anode layer 310 to extend below the non-opening area 210 and the two ends of the auxiliary anode layer 320 to extend into the interior of the non-opening area 210, with the two ends of the auxiliary anode layer 320 extending beyond the two ends of the main anode layer 310 respectively, electrical synergy and stress optimization of the anode layer in the folded state are achieved, thereby effectively improving display uniformity and enhancing structural stability. Specifically, by ensuring that the projections of both the main anode layer 310 and the auxiliary anode layer 320 cover the projection of the opening area, it is ensured that the entire pixel opening area is covered by an anode, avoiding shrinkage of the light-emitting area or uneven current distribution due to insufficient anode size. The two ends of the main anode layer 310 extend below the non-opening area 210, helping to disperse stress to the non-opening area 210 during folding and preventing stress concentration from damaging the light-emitting layer. The two ends of the auxiliary anode layer 320 extend into the interior of the non-opening area 210, and both ends extend beyond the two ends of the main anode layer 310, allowing for more complete deformation of the auxiliary anode layer 320 in the folded state. This enables it to more effectively utilize its characteristic of increased resistance during compression, thereby actively reducing the current injected into the light-emitting layer and avoiding localized overbrightness caused by increased current on the compressed side. By utilizing the dimensional differences and spatial misalignment between the main anode layer 310 and the auxiliary anode layer 320 in the horizontal direction, the electrical and mechanical properties of the anode side in the folded state are synergistically optimized, significantly improving the display uniformity of the folded area and extending the lifespan of the device.
[0036] It should be noted that, as Figure 1 As shown, the length direction is parallel to the X direction, and the height direction is parallel to the Z direction.
[0037] It should also be noted that the opening area refers to the area on the pixel definition layer 20 where a window is opened, that is, the area where the pixel actually emits light, such as... Figure 1 As shown, the cross-sectional shape of the opening area is a trapezoidal shape with a larger top and a smaller bottom, that is, the bottom opening size of the pixel definition layer 20 facing the substrate 10 is smaller than the top opening size of the side away from the substrate 10; the non-opening area 210 refers to the solid part of the pixel definition layer 20 surrounding the opening area, which is used to isolate adjacent pixels.
[0038] In some embodiments, the auxiliary anode layer 320 includes a main body segment 3201 and a reinforcing segment 3202; the main body segment 3201 and the main anode layer 310 are stacked together; the reinforcing segments 3202 are respectively disposed at both ends of the main body segment 3201 in the length direction and extend into the interior of the non-opening region 210; the reinforcing segment 3202 includes a plurality of alternately arranged upward convex segments 3203 and a plurality of downward concave segments 3204.
[0039] By setting the auxiliary anode layer 320 as a structure combining the main body segment 3201 and the reinforcing segment 3202, and forming alternating convex upper segments 3203 and concave lower segments 3204 in the reinforcing segment 3202, the electrical regulation capability and mechanical stability of the auxiliary anode layer 320 in the folded state are significantly enhanced, thereby effectively improving the display uniformity and extending the device lifespan. Specifically, the main body segment 3201 and the main anode layer 310 are stacked and connected in parallel, providing a stable basic electrical path for the auxiliary anode layer 320. Reinforcing segments 3202 are respectively disposed at both ends of the main body segment 3201 along its length and extend into the interior of the non-opening area 210, giving the auxiliary anode layer 320 greater deformation space and stronger structural anchoring at both ends of the folded area. When the display panel is bent, the auxiliary anode layer 320 at the bottom is compressed. The alternating upward convex segments 3203 and downward concave segments 3204 in the reinforcing segments 3202 form an "M-shaped" winding structure. This structure provides an ultra-long deformation area, enabling multiple resistance change steps to be generated during compression, thereby achieving multi-level brightness compensation and effectively improving the poor brightness separation of OLEDs at low grayscale levels. Furthermore, the reinforcing segment 3202 extends into the non-opening area 210, forming a multi-contact surface with the pixel definition layer 20. This multi-contact surface fixation effectively improves the deformation stability of the auxiliary anode layer 320 during repeated bending, preventing delamination or breakage due to excessive deformation. Simultaneously, it establishes a reliable mechanical coupling between the auxiliary anode layer 320 and the pixel definition layer 20, further enhancing the structural reliability of the folded area. Through the synergistic effect of the main segment 3201 and the reinforcing segment 3202, this solution achieves active current reduction on the anode side, avoids localized overbrightness, and simultaneously improves display detail and the mechanical stability of the folded area.
[0040] It should be noted that the greater the number and density of the convex segments 3203 and concave segments 3204, the more contact surfaces there are between the auxiliary anode layer 320 and the pixel definition layer 20, forming a denser multi-contact surface structure. This multi-contact surface fixing effect can disperse the stress generated during folding to more local contact areas, effectively suppressing stress concentration and significantly improving the deformation stability of the auxiliary anode layer 320 during repeated bending. Simultaneously, the densely distributed convex segments 3203 and concave segments 3204 further extend the deformation path of the auxiliary anode layer 320 in the length direction, helping to achieve a smoother and finer resistance change step under compression, thereby improving the accuracy of brightness compensation and the fineness of grayscale display. Therefore, by optimizing the number and distribution density of the convex segments 3203 and concave segments 3204, the display effect can be further improved while enhancing structural stability.
[0041] It should also be noted that the shapes of the convex segments 3203 and concave segments 3204 can be, but are not limited to, one or more of the following: arc-shaped, trapezoidal, triangular, or irregular wavy. The arrangement of the convex segments 3203 and concave segments 3204 is not limited to strict alternation; periodic repeating units can also be used, with each unit containing multiple different combinations of convex segments 3203 and concave segments 3204. For example, in some embodiments, a unit structure of "one convex segment 3203 and two concave segments 3204" can be repeatedly arranged to achieve an asymmetrical deformation response; in other embodiments, convex segments 3203 and concave segments 3204 of different heights can be alternately arranged.
[0042] It should also be noted that the auxiliary anode layers 320 located below each pixel maintain consistent dimensions along their length; that is, the length of the main body segment 3201 and the distribution range of the reinforcing segments 3202 of each auxiliary anode layer 320 are identical. By ensuring that the auxiliary anode layers 320 have consistent geometric dimensions along their length, it can be ensured that the initial impedance values of each pixel are essentially the same in the non-bent state, thereby providing a uniform electrical reference for the display panel. When the display panel is bent, each auxiliary anode layer 320 undergoes varying degrees of compression deformation depending on the degree of bending at its location. However, because its initial impedance is consistent, the change in resistance is only related to the degree of bending and is not affected by structural differences between pixels, thus achieving uniformity and predictability of brightness compensation in the bent state. In addition, the consistent dimensions of the auxiliary anode layers 320 also facilitate the use of uniform process parameters for fabrication, which is beneficial for improving manufacturing yield and product consistency.
[0043] It should also be noted that the main body segment 3201 is in direct contact with the main anode layer 310, and the two form a stacked and bonded structure physically, and are connected in parallel electrically.
[0044] It should also be noted that during the material design phase, the resistance-strain characteristic curve of the conductive folded metamaterial can be preset by adjusting parameters such as its formulation, microstructure, thickness, and porosity, thereby determining the gradient and dynamic range of brightness compensation. This material-level compensation is inherent and passive, capable of instantaneous response when bending occurs, requiring no external control signal, and providing a stable and reliable basic framework for brightness management. Meanwhile, the display panel's driving circuit can also actively fine-tune the brightness control based on the inherent compensation of the conductive folded metamaterial by adjusting the anode or cathode voltage according to actual display needs. This active control mechanism can compensate for deviations caused by individual material differences, environmental changes, and long-term aging, further improving the accuracy of brightness control. The alternating upward convex segments 3203 and downward concave segments 3204 in the reinforced segment 3202 form an "M-shaped" winding structure. This structure provides an ultra-long deformation area. The longer the deformation area, the more deformation stages it can accommodate, and the number of resistance change steps also increases accordingly. This allows for matching brightness compensation for finer grayscale division. It effectively improves the brightness separation of the bending area at low grayscale, making the grayscale transition smoother and more natural, and significantly improving the display detail.
[0045] In some embodiments, the cathode layer 50 includes a first cathode portion 510, a second cathode portion 520, and a third cathode portion 530; the first cathode portion 510 covers the side of the organic light-emitting functional layer 40 away from the substrate 10; the second cathode portion 520 covers the side of the non-opening region 210 away from the substrate 10; in the height direction, the distance between the second cathode portion 520 and the substrate 10 is greater than the distance between the first cathode portion 510 and the substrate 10; the two ends of the third cathode portion 530 are respectively connected to the first cathode portion 510 and the second cathode portion 520, and the third cathode portion 530 covers the organic light-emitting functional layer 40.
[0046] By covering the side of the organic light-emitting functional layer 40 away from the substrate 10 with the first cathode portion 510, located in the opening area and at a lower position, a stable electron injection interface is ensured with the organic light-emitting functional layer 40; the second cathode portion 520 covers the side of the non-opening area 210 away from the substrate 10 and is located at a higher position, forming a height difference between the opening area and the non-opening area 210 of the cathode layer 50; the third cathode portion 530 connects the first cathode portion 510 and the second cathode portion 520 and covers the organic light-emitting functional layer 40; since there is a height difference between the first cathode portion 510 and the second cathode portion 520, and they are located in the opening area and the non-opening area 210 respectively, and are supported by different structural layers below them, the first cathode portion 510 and the second cathode portion 520, which have higher rigidity, deform less when bent, while the third cathode portion 530, which connects the two, is in a transition position in structure and becomes the main bearing area for tensile deformation, thereby concentrating the overall deformation of the cathode layer 50 in the third cathode portion 530, avoiding structural damage caused by uniform stress on the entire cathode layer 50. Furthermore, the third cathode portion 530 covers the organic light-emitting functional layer 40, maintaining contact with it in the unbent state to ensure an intact electron injection path. When bending occurs, the contact area between the third cathode portion 530 and the organic light-emitting functional layer 40 it covers is reduced due to stretching, thereby reducing the amount of electron injection. Combined with the electrical adjustment on the anode side, active compensation of brightness on the cathode side is achieved. Through the spatial positional differences and deformation concentration design of the first cathode portion 510, the second cathode portion 520, and the third cathode portion 530, this solution ensures the stability of electron injection into the cathode layer 50 while achieving controllable deformation and self-compensation of brightness under bending conditions, significantly improving the display uniformity of the folded area and the bending reliability of the cathode layer 50.
[0047] It should be noted that the first cathode section 510, the second cathode section 520, and the third cathode section 530 are continuous and integral, and can be formed through the same process step.
[0048] In some embodiments, the display panel further includes a first encapsulation layer 60 and a second encapsulation layer 70; the first encapsulation layer 60 is disposed on the side of the first cathode portion 510 away from the substrate 10; in the length direction, there is a gap 80 between both ends of the first encapsulation layer 60 and the non-opening area 210, and the third cathode portion 530 is located in the gap 80; the second encapsulation layer 70 is disposed on the side of the second cathode portion 520 away from the substrate 10 and the side of the first encapsulation layer 60 away from the substrate 10, and spans across the gap 80.
[0049] A first encapsulation layer 60 is disposed on the side of the first cathode portion 510 away from the substrate 10, covering the opening area. Its two ends form a gap 80 with the non-opening area 210 along the length direction, and the third cathode portion 530 is located within this gap 80. This structural design allows the third cathode portion 530 to be in a relaxed state when not bent, without direct contact with the first encapsulation layer 60, thus avoiding limitations on its deformation capacity due to the encapsulation layer. When the display panel is bent, the third cathode portion 530, as the main deformation-bearing area of the cathode layer 50, can freely extend or contract within the gap 80, unrestricted by the first encapsulation layer 60, thereby avoiding stress concentration or material damage caused by limited deformation. A second encapsulation layer 70 is disposed on the side of the second cathode portion 520 facing away from the substrate 10 and the side of the first encapsulation layer 60 facing away from the substrate 10, and spans across the gap 80, forming a continuous encapsulation structure. The second encapsulation layer 70 spanning across the gap 80 ensures the overall sealing of the display panel, preventing water and oxygen from entering through the gap 80, while not affecting the free deformation of the third cathode portion 530 within the gap 80. Through the layered arrangement and spatial coordination of the first encapsulation layer 60 and the second encapsulation layer 70, this solution ensures encapsulation reliability while providing sufficient deformation space for the deformation-concentrated area of the cathode layer 50, achieving a balance between encapsulation protection and deformation freedom, significantly enhancing the bending reliability and long-term service life of the folding area.
[0050] It should be noted that the first encapsulation layer 60 is an organic insulating layer used to provide flexibility and stress buffering. The material of the first encapsulation layer 60 can be acrylate, epoxy resin, polyimide, etc.; the second encapsulation layer 70 is an inorganic insulating layer used to provide water and oxygen barrier. The material of the second encapsulation layer 70 can be silicon nitride (SiNx), silicon oxide (SiOx), aluminum oxide (AlOx), etc.; in addition, the height of the first encapsulation layer 60 can be 10μm-15μm, and the height of the conductive folded metamaterial can be 5μm-10μm.
[0051] It should also be noted that the length of the pore 80 can be 2μm-5μm.
[0052] It should also be noted that the second encapsulation layer 70 is disposed across the gap 80, that is, the second encapsulation layer 70 forms a bridging structure above the gap 80, only covering the surface and not filling the entire gap 80, thereby reserving the gap 80 as the deformation space of the third cathode portion 530, and the third cathode portion 530 is in a relaxed stacked state within the gap 80.
[0053] like Figure 2 , Figure 3 As shown, in some embodiments, when the display panel is bent, the third cathode portion 530 is stretched, and the contact area between the third cathode portion 530 and the organic light-emitting functional layer 40 is reduced.
[0054] When the display panel is folded inwards, the top cathode layer 50 is stretched. At this time, the cathode layer 50 undergoes two changes simultaneously: firstly, because the cathode layer 50 is formed of a conductive folded metamaterial, its resistance decreases during stretching, which facilitates current flow; secondly, the third cathode portion 530, as the main deformation-bearing area of the cathode layer 50, experiences a decrease in contact area with the organic light-emitting functional layer 40 during stretching, leading to a decrease in electron injection. Through the balance between the decrease in resistance and the reduction in contact area, the current on the cathode side is maintained at a level close to that of the non-bending state, avoiding the problem of a significant drop in current caused by increased resistance and reduced contact area due to stretching in traditional metal cathodes. Meanwhile, the auxiliary anode layer 320 at the bottom is compressed during bending, increasing its resistance and actively reducing the hole current injected into the organic light-emitting functional layer 40. The cathode side achieves current stabilization through reduced resistance and smaller contact area, while the anode side achieves active current reduction through increased resistance. The synergistic effect of these two mechanisms ensures that the brightness of pixels in the bent area remains consistent with that in the non-folded area, avoiding the problem of the folded area becoming significantly darker due to stretching or significantly brighter due to compression. This achieves automatic brightness balance under bending conditions and significantly improves the display uniformity of the folded area. Furthermore, the reduction in the contact area between the third cathode portion 530 and the organic light-emitting functional layer 40 actively shrinks the light-emitting area to the less stressed central region, preventing the light-emitting layer from being subjected to current surges at high-stress edges, thereby reducing the fatigue damage rate of the light-emitting layer during repeated bending. Through the synergy of this deformation-induced contact area adjustment mechanism and the resistance compensation mechanism, this solution effectively protects the light-emitting layer while achieving brightness self-balancing, significantly extending the device's lifespan.
[0055] It should be noted that the third cathode portion 530 is located in the gap 80 between the two ends of the first encapsulation layer 60 and the non-opening area 210. There are no other structures that form a fixed constraint on the third cathode portion 530, so that the third cathode portion 530 has sufficient freedom in space and can deform freely when bent. In its unbent state, the third cathode portion 530 is in a relaxed stacked configuration, forming a large contact area with the organic light-emitting functional layer 40 to ensure unobstructed electron injection path. When the display panel is bent, the third cathode portion 530 is stretched, and its geometry changes in two ways: First, the originally relaxed stacked structure is straightened, and the contact method with the organic light-emitting functional layer 40 gradually changes from surface contact to line contact or even point contact, resulting in a significant reduction in the contact area; second, since the third cathode portion 530 is formed of a conductive folded metamaterial, this material has lateral contraction characteristics (Poisson effect) when stretched, that is, while the length direction is stretched, the width direction is correspondingly narrowed, further reducing its contact width with the organic light-emitting functional layer 40. The combination of these two effects reduces the contact area between the third cathode portion 530 and the organic light-emitting functional layer 40 during bending, thereby effectively regulating the electron injection amount. After bending and recovery, the third cathode portion 530 can spring back to a relaxed stacked state, and the contact area returns to the initial level, ensuring the repeatability of contact characteristics in multiple bending cycles. Through this free deformation design and reversible adjustment mechanism of contact area, the third cathode portion 530 can achieve active adjustment of electron injection amount when bending, providing a structural basis for cathode-side brightness compensation.
[0056] like Figure 2 , Figure 3 As shown, in some embodiments, the third cathode portion 530 is obliquely connected to the first cathode portion 510 and the second cathode portion 520, and the third cathode portion 530 has an oblique angle with the height direction; when the display panel is bent, the third cathode portion 530 is stretched, the oblique angle increases, and the contact area between the third cathode portion 530 and the organic light-emitting functional layer 40 decreases.
[0057] The inclined connection design makes the third cathode portion 530 a concentrated area of tensile deformation when bent. Specifically, the first cathode portion 510 and the second cathode portion 520 are located in the open area and the non-open area 210, respectively, and are both supported and fixed by a rigid structure, resulting in small deformation. However, the third cathode portion 530 is located in the gap 80, without continuous rigid structural support and fixed, and the inclined connection has two ends with a height difference, making it a weak support area mechanically. When bending occurs, the tensile stress is mainly concentrated on this inclined structure, thereby avoiding damage to the first cathode portion 510 and the second cathode portion 520 due to excessive stress, and effectively enhancing the structural reliability of the cathode layer 50. Meanwhile, the tilted structure provides a geometric basis for the active adjustment of the contact state. In the unbent state, the tilted third cathode portion 530 forms a large-area surface contact with the organic light-emitting functional layer 40; when bending stretches the third cathode portion 530, the angle between its extension direction and height direction increases, and the contact mode changes from surface contact to line contact or even point contact, significantly reducing the contact area. This change in geometric shape automatically matches the degree of bending, realizing passive and adaptive adjustment of the contact area, providing a structural basis for self-compensation of the cathode-side brightness. It should be noted that by adjusting the tilt angle, width, thickness, and other geometric parameters of the third cathode portion 530, the rate and magnitude of the reduction in contact area during stretching can be controlled.
[0058] It should be noted that the initial tilt angle of the third cathode portion 530 can be flexibly set according to the bending characteristics of the display panel and the brightness compensation requirements. For example, for applications with a large degree of bending or requiring a fast response, a smaller initial tilt angle can be set to make the change in contact area during bending more sensitive; for applications with a small degree of bending or requiring a smooth transition, a larger initial tilt angle can be set to make the change in contact area more gradual.
[0059] It should also be noted that, such as Figure 2 , Figure 3 As shown, when the display panel is not bent, the angle between the third cathode portion 530 and the height direction is α, and when the display panel is bent, the angle between the third cathode portion 530 and the height direction is β, where α < β.
[0060] It should also be noted that, in order to accommodate the inclined arrangement of the third cathode portion 530, the extension direction of the gap 80 is also provided with an basically consistent inclined angle with the height direction. In other words, the gap 80 does not necessarily have to extend parallel to the height direction, but can be adapted to the required inclined angle of the third cathode portion 530, so that the third cathode portion 530 can be accommodated in a natural and comfortable inclined posture within the gap, avoiding additional bending stress or poor contact due to mismatch in direction.
[0061] In some embodiments, the main anode layer 310 is formed of a metallic material.
[0062] The main anode layer 310, formed from a metallic material, possesses high mechanical strength and good conductivity. During the folding process, the main anode layer 310, located between the organic light-emitting functional layer 40 and the auxiliary anode layer 320, acts as a stress buffer, effectively dispersing the stress generated by bending and preventing stress concentration from damaging the organic light-emitting functional layer 40. Simultaneously, a stable hole injection interface can be formed between the metallic material and the organic light-emitting functional layer 40, ensuring uniform hole injection and improving luminous efficiency. The parallel structure of the metallic main anode layer 310 and the conductive folded metamaterial auxiliary anode layer 320 ensures structural stability while providing a reliable electrical path for brightness compensation on the anode side.
[0063] It should be noted that the metallic material can be silver. The silver-formed main anode layer 310 has a certain strength, which can effectively disperse the stress generated by bending, forming a flexible-plastic-elastic strength transition structure between the flexible auxiliary anode layer 320 and the elastic organic light-emitting functional layer 40. This transition structure allows the organic light-emitting functional layer 40 to deform slowly when bent and rebound smoothly when recovering, avoiding damage to the organic light-emitting functional layer 40 caused by sudden stress changes, thereby significantly improving the service life of the light-emitting layer.
[0064] This application also provides a display device, including the display panel provided in the foregoing embodiments of this application.
[0065] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.
[0066] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.
[0067] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A display panel, characterized in that, include: substrate; A pixel definition layer protrudes from one side of the substrate and forms a plurality of spaced pixel receiving areas; An anode structure is disposed within the pixel accommodating area, including a main anode layer and an auxiliary anode layer connected in parallel with the main anode layer, wherein the auxiliary anode layer is disposed on the side of the main anode layer facing the substrate; An organic light-emitting functional layer is disposed within the pixel accommodating area and covers the main anode layer; A cathode layer covers the side of the pixel definition layer opposite to the substrate, and the side of the organic light-emitting functional layer opposite to the substrate; When the display panel is bent, the auxiliary anode layer is compressed and its resistance increases, while the cathode layer is stretched and its resistance decreases.
2. The display panel according to claim 1, characterized in that, Both the auxiliary anode layer and the cathode layer are formed of a conductive folded metamaterial; wherein the conductive folded metamaterial has an increased resistance when compressed and a decreased resistance when stretched.
3. The display panel according to claim 1, characterized in that, The pixel definition layer includes a plurality of spaced-apart opening regions and a non-opening region located between two adjacent opening regions, the opening regions forming the pixel accommodating area; On a plane perpendicular to the height direction, the projection of the main anode layer covers the projection of the opening area, and the projection of the auxiliary anode layer covers the projection of the opening area; In the length direction, both ends of the main anode layer extend below the non-opening region, and both ends of the auxiliary anode layer extend into the interior of the non-opening region, with the ends of the auxiliary anode layer respectively extending beyond the ends of the main anode layer.
4. The display panel according to claim 3, characterized in that, The auxiliary anode layer includes: The main body segment is stacked with the main anode layer; The reinforcing segments are respectively disposed at both ends of the main body segment in the length direction and extend into the interior of the non-opening area; the reinforcing segments include multiple convex segments and multiple concave segments arranged alternately.
5. The display panel according to claim 3, characterized in that, The cathode layer includes: The first cathode portion covers the side of the organic light-emitting functional layer that is away from the substrate; The second cathode portion covers the side of the non-opening area away from the substrate; in the height direction, the distance between the second cathode portion and the substrate is greater than the distance between the first cathode portion and the substrate; The third cathode portion is connected to the first cathode portion and the second cathode portion at both ends, and the third cathode portion covers the organic light-emitting functional layer.
6. The display panel according to claim 5, characterized in that, The display panel also includes: A first encapsulation layer is disposed on the side of the first cathode portion facing away from the substrate; in the length direction, there are gaps between both ends of the first encapsulation layer and the non-opening area, and the third cathode portion is located within the gaps; The second encapsulation layer is disposed on the side of the second cathode portion away from the substrate and on the side of the first encapsulation layer away from the substrate, and spans across the gap.
7. The display panel according to claim 6, characterized in that, When the display panel is bent, the third cathode portion is stretched, and the contact area between the third cathode portion and the organic light-emitting functional layer decreases.
8. The display panel according to claim 7, characterized in that, The third cathode portion is obliquely connected to the first cathode portion and the second cathode portion, and the third cathode portion has an oblique angle with the height direction; When the display panel is bent, the third cathode portion is stretched, the tilt angle increases, and the contact area between the third cathode portion and the organic light-emitting functional layer decreases.
9. The display panel according to any one of claims 1-8, characterized in that, The main anode layer is formed of a metallic material.
10. A display device, characterized in that, Includes the display panel as described in any one of claims 1-9.