Flexible display panel and foldable device

Abstract

This application relates to a flexible display panel and a foldable device. The flexible display panel includes a display layer comprising pixel display areas and pixel gap areas, the pixel gap areas being located around the pixel display areas. It also includes: a reversible photocurable support structure whose projection falls into the pixel gap areas; the reversible photocurable support structure is cured under irradiation by a first light source and reverse-cured under irradiation by a second light source; and a light emitting device, positioned perpendicularly to the reversible photocurable support structure, for emitting the first light source when the flexible display panel is in a bent state and emitting the second light source when the flexible display panel returns to a flat state. This application enables the flexible display panel to resist bending stress when folded and to restore and repair creases that have occurred after flattening by softening the material, thus achieving the dual functions of crease prevention and active crease recovery.

Description

Technical Field

[0001] This application relates to the field of displays, and more particularly to a flexible display panel and a foldable device. Background Technology

[0002] Flexible display technology represents a core direction for the display industry's upgrade towards thinner, lighter, and more bendable designs. It has been widely applied in wearable devices, e-readers, foldable screen terminals, and automotive flexible displays, becoming a core display carrier for next-generation smart terminals and IoT devices. However, during daily bending, folding, and pressing, stress concentration areas in these flexible display panels are prone to permanent, irreversible creases, becoming a common technical bottleneck in the industry and severely limiting product lifespan and user experience. Summary of the Invention

[0003] This application provides a flexible display panel and a foldable device to solve the problem that in the prior art, the stress concentration area of ​​the flexible display panel is prone to permanent irreversible creases during daily bending, folding and pressing.

[0004] In a first aspect, this application provides a flexible display panel, the flexible display panel including a display layer, the display layer including a pixel display area and a pixel gap area, the pixel gap area being located around the pixel display area, the flexible display panel further including: A reversible light-curing support structure, the projection of which falls into the pixel gap area; the reversible light-curing support structure is cured under the irradiation of a first light and reverse-cured under the irradiation of a second light. A light emitting device is positioned perpendicularly to the reversible photocurable support structure. It is used to emit a first light beam when the flexible display panel is in a bent state to cure the reversible photocurable support structure, and to emit a second light beam when the flexible display panel returns to a flat state to reverse the curing of the reversible photocurable support structure.

[0005] Furthermore, the reversible photocurable support structure includes multiple photocurable resin particles, and the photocurable resin particles are covered with a closed transparent shell.

[0006] Furthermore, the structural formula of the photocurable resin is: ; Wherein, the R basis can be any of the following: ; ; .

[0007] Furthermore, the first ray is ultraviolet light, and the second ray is infrared light.

[0008] Furthermore, the flexible display panel also includes: A sensing layer, disposed on the display layer, is used to detect the bending stress in the bending area of ​​the flexible display panel, and to determine whether the flexible display panel is in a bent or flat state based on the bending stress data.

[0009] Furthermore, the sensing layer includes a protective layer, a pressure sensing layer, and a conductive connection layer arranged sequentially from top to bottom; The protective layer is a transparent structure; The pressure sensing layer includes uniformly distributed pressure sensing units, and the distribution area of ​​the pressure sensing units corresponds perpendicularly to the pixel gap area. The conductive connection layer includes conductive lines, and the distribution area of ​​the conductive lines corresponds perpendicularly to the pixel gap area.

[0010] Furthermore, the reversible light-curing support structure is embedded in the pixel gap region of the display layer; The light emitting device includes a matrix of miniature LED beads, which includes first and second LED beads arranged in an alternating pattern. The first LED beads are used to emit a first light beam, and the second LED beads are used to emit a second light beam.

[0011] Furthermore, the flexible display panel includes: A support layer is located above the display layer. The support layer includes a support area and a non-support area. The support area is perpendicularly corresponding to the pixel gap area of ​​the display layer, and the non-support area is perpendicularly corresponding to the pixel display area of ​​the display layer. The reversible light-curing support structure is located in the support area. The light emitting device is a multilayer organic light-emitting device, comprising, from top to bottom, a first organic light-emitting layer, a hole injection / transport layer, a first anode layer, a transparent charge generation layer, an electron injection / transport layer, a second organic light-emitting layer, and a second anode layer, wherein the first organic light-emitting layer is used to emit a first light ray, and the second organic light-emitting layer is used to emit a second light ray.

[0012] Furthermore, the flexible display panel further includes: a partition driving layer disposed below the display layer, the partition driving layer comprising: A display driving thin-film transistor is disposed at a position perpendicular to the pixel display area and is used to drive the pixel display area to emit light; A dimming driving thin-film transistor is disposed at a position perpendicular to the multilayer organic light-emitting device, and is used to drive the multilayer organic light-emitting device to emit a first light or a second light. The dimming driving thin-film transistor includes a first dimming driving thin-film transistor and a second dimming driving thin-film transistor, wherein the first dimming driving thin-film transistor is connected to the first anode layer, and the second dimming driving thin-film transistor is connected to the second anode layer.

[0013] Secondly, this application provides a foldable device, including the aforementioned flexible display panel.

[0014] Compared with the prior art, the technical solution provided in this application has the following advantages: The flexible display panel provided in this application includes a reversible photocurable support structure and a light emitting device corresponding to its position. When the flexible display panel is in a bent state, the light emitting device emits a first light beam, causing the reversible photocurable support structure to solidify under the irradiation of the first light beam, forming a rigid support structure. This allows the flexible display panel to meet conventional hardness requirements, resist bending stress, and prevent plastic deformation of the substrate and display layer, thus avoiding creases at the source. When the flexible display panel is in a flat state, the light emitting device emits a second light beam, causing the reversible photocurable support structure to reverse solidify, increasing its fluidity. The flexible display panel then releases the rigid support, restoring its original flexible bending characteristics and eliminating creases, thereby achieving the dual functions of crease prevention and active crease recovery. Furthermore, both the reversible photocurable support structure and the light emitting device are positioned corresponding to the pixel gap area, ensuring that the first / second light beam emission area is separated from the pixel display area. Therefore, it is possible to achieve crease prevention and active crease recovery while ensuring the normal display effect of the pixel display area. 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, those skilled in the art can obtain other drawings 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 1This is a structural diagram of a flexible display panel provided in an embodiment of this application; Figure 2 A structural diagram of a liquid crystal panel provided in an embodiment of this application; Figure 3 A structural diagram of an organic electroluminescent panel provided in an embodiment of this application; Figure 4 A structural diagram of a multilayer organic light-emitting device in an organic electroluminescent panel provided in this application embodiment; Among them, 1-display layer, 2-reversible light-curing support structure, 3-light emitting device, 21-sensing layer, 22-liquid crystal display layer, 23-substrate, 221-pixel display area, 222-pixel gap area, 222a-reversible light-curing support structure, 222b-pixel black matrix, 231-micro LED matrix, 211-protective layer, 212-pressure sensing layer, 213-conductive connection layer, 31-sensing layer, 32-support layer, 33-dual-zone light-emitting layer. 34-Divider driving layer, 35-Substrate, 331-Pixel display area, 332-Pixel gap area, 321-Reversible light-curing support structure, 322-Pixel black matrix, 333-Multilayer organic light-emitting device, 333a-Ultraviolet organic light-emitting layer, 333b-Hole injection / transport layer, 333c-First anode layer, 333d-Transparent charge generation layer, 333e-Electron injection / transport layer, 333f-Infrared organic light-emitting layer, 333g-Second anode layer. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] To address the technical problem that in existing flexible display panels, permanent and irreversible creases are easily generated in stress concentration areas during daily bending, folding, and pressing, this application provides a flexible display panel that can resist bending stress when folded and restore existing creases after being laid flat by softening the material, thus achieving the dual functions of crease prevention and active crease recovery.

[0022] Example 1 Figure 1 A structural diagram of a flexible display panel provided in an embodiment of this application is shown below. Figure 1 As shown, the flexible display panel of this embodiment includes a display layer 1, which includes a pixel display area 11 and a pixel gap area 12. The pixel gap area 12 is located around the pixel display area 11. The flexible display panel also includes: a reversible light-curing support structure 2, whose vertical projection falls into the pixel gap area 12. The reversible light-curing support structure 2 is cured under the irradiation of a first light source, becoming solid, and is reverse-cured under the irradiation of a second light source, returning to a liquid state; and a light emitting device 3, the position of which is perpendicular to the reversible light-curing support structure 2, that is, the position of the light emitting device 3 is set directly below the reversible light-curing support structure 2, so that the reversible light-curing support structure 2 is positioned below the light emitting device. The first or second light emitted by the light emitting device 3 is used to emit the first light when the flexible display panel is in a bent state, so that the reversible light-curing support structure 2 is cured under the irradiation of the first light to form a rigid support structure, so that the flexible display panel reaches the corresponding hardness requirements, resists bending stress, prevents plastic deformation of the substrate and liquid crystal layer, and avoids the formation of creases from the root. When the flexible display panel returns to a flat state, the light emitting device 3 emits the second light, so that the reversible light-curing support structure 2 is reverse-cured, returns to a liquid state, increases fluidity, so that the flexible display panel is released from rigid support, restores its original flexible bending characteristics, and thus makes the creases on the flexible display panel disappear.

[0023] The flexible display panel in this embodiment features a reversible photocurable support structure and a corresponding light emitting device. When the flexible display panel is bent, the light emitting device emits a first light beam, causing the reversible photocurable support structure to solidify under the first light beam, forming a rigid support structure. This allows the flexible display panel to achieve the required hardness, resist bending stress, and prevent plastic deformation of the substrate and display layer, thus avoiding creases at the source. When the flexible display panel is laid flat, the light emitting device emits a second light beam, causing the reversible photocurable support structure to reverse solidify, increasing its fluidity. This allows the flexible display panel to release the rigid support, restoring its original flexible bending characteristics and eliminating creases. This achieves the dual functions of crease prevention and active crease recovery. Furthermore, both the reversible photocurable support structure and the light emitting device are positioned corresponding to the pixel gap area, ensuring separation between the first / second light beam emission area and the pixel display area. This ensures normal display performance of the pixel display area while preventing and actively recovering creases.

[0024] Example 2 If the particles in the reversible photocurable support structure are too large, the first light rays cannot quickly penetrate the structure during curing, resulting in a slower curing speed and a poorer anti-crease effect. To address this issue, in this embodiment, the reversible photocurable support structure 2 includes multiple photocurable resin particles, each encased in a sealed transparent shell. This ensures light penetration while preventing the photocurable resin from flowing out after reverting to a liquid state, thus maintaining a consistent particle size. Specifically, photocurable resin monolayers can be formed by horizontally and vertically arranging resin particles, and then stacked vertically to form a resin particle group, thereby constituting the reversible photocurable support structure 2. This resin particle structure design reduces the particle size of the reversible photocurable support structure 2, facilitating rapid penetration of the first light rays and enabling rapid curing. The light transmittance of the photocurable resin particles is close to that of glass, and they are colorless and transparent. Even after curing, they do not alter the light transmission characteristics of the liquid crystal layer—essentially adding an "invisible transparent support" to the pixel gap area, without affecting the display.

[0025] If the aforementioned reversible photocurable support structure can only cure when the flexible panel is folded, and cannot quickly reverse-cur after the flexible panel is laid flat, it can only prevent creases, but cannot quickly restore them. To ensure that the creases of the reversible photocurable support structure 2 disappear quickly after the flexible panel is laid flat, the photocurable resin needs to have the characteristic of rapid reverse curing under a second light source. In this embodiment, a disulfide bond-type reversible photocurable resin is selected. After the flexible panel is laid flat, irradiation with the second light source can break the disulfide bonds, thereby restoring the reversible photocurable support structure 2 to a liquid state, increasing its fluidity. This releases the rigid support from the flexible display panel, restoring its original flexible bending characteristics, and causing the creases to disappear quickly.

[0026] The structural formula of the above-mentioned photocurable resin is: Wherein, the R basis can be any of the following: , , .

[0027] The disulfide bond-type reversible photocurable material used in this embodiment has a monomer that is a five-membered ring disulfide bond compound (such as lipoic acid and its derivatives), with the general formula: R-CH(SS-CH2-CH2). - .

[0028] Under 365 nm ultraviolet light, the monomer undergoes reversible ring-opening polymerization mediated by disulfide bonds to become a solid polymer. The polymer backbone contains dynamic disulfide bonds (-SS-), with the general structural formula -[CH(R)-SS-CH2-CH2]. - n; Under near-infrared light irradiation, disulfide bonds break, polymer depolymerizes and reverts to a liquid state, achieving photocontrolled reversible phase transition. The specific reaction formula is as follows: .

[0029] The aforementioned photocurable resin can be cured under ultraviolet light irradiation and can be reverse-cured under infrared light irradiation. Therefore, the first light ray is ultraviolet light and the second light ray is infrared light. The aforementioned light emitting device can emit both ultraviolet light and infrared light.

[0030] While the folded and laid-out states of a flexible panel are visible to the naked eye, controlling the type of light emitted by a light-emitting device based on these states requires converting the folded and laid-out state into an electrical signal. Since the bending stress in the bending area differs between the folded and laid-out states, detecting this stress can determine whether the flexible panel is folded or laid-out. Based on this consideration, the flexible display panel in this embodiment further includes a sensing layer disposed on top of the display layer. This sensing layer detects the bending stress in the bending area of ​​the flexible display panel and determines whether the panel is folded or laid-out based on the bending stress data. By detecting the bending stress in the bending area of ​​the flexible display panel through the sensing layer, the bending stress can accurately determine whether the panel is folded or laid-out: if the bending stress exceeds a certain threshold, it indicates that the flexible panel is folded; if the bending stress does not exceed the threshold, it indicates that the flexible panel is laid-out.

[0031] The aforementioned sensing layer comprises, from top to bottom, a protective layer, a pressure sensing layer, and a conductive connection layer. The sensing layer includes pressure sensing units (such as pressure-sensitive resistors). To prevent the pressure sensing units from being contaminated or damaged, a protective layer is required. To avoid affecting the normal display of the flexible display panel, the protective layer should be transparent. In addition, conductive lines are also required to output the pressure signal detected by the pressure sensing units to the control chip. Therefore, the aforementioned protective layer is a transparent structure. The pressure sensing layer includes uniformly distributed pressure sensing units. The conductive connection layer includes conductive lines.

[0032] The display layer includes a pixel display area and a pixel gap area. The pixel gap area includes a pixel black matrix area. The pixel display area is used for normal display. If the conductive lines of the conductive connection layer or the vertical projection of the pressure sensing units in the pressure sensing layer are distributed in the pixel display area, it will also affect the normal display of the display panel. Therefore, it is preferable to place the aforementioned conductive lines and pressure sensing units in the area corresponding to the pixel gap area, that is, the distribution area of ​​the conductive lines and the distribution area of ​​the pressure sensing units are vertically corresponding to the pixel gap area. Since the pixel gap area is not used for display, setting the distribution area of ​​the conductive lines and pressure sensing units to correspond to the pixel gap area can maximize the obstruction of the pixel display area by the conductive lines, ensuring normal display effect.

[0033] As mentioned above, the light emitting device emits a first light beam when the flexible display panel is in a bent state and emits a second light beam when the flexible display panel returns to a flat state. Therefore, the light emitting device needs to be able to emit both the first and second light beams, and the light propagation path must be aligned with the reversible light curing support structure 2 when either light beam is emitted. In this embodiment, the reversible light curing support structure is embedded in the pixel gap area of ​​the display layer. The light emitting device includes a micro LED matrix. In order to ensure the uniformity of curing and decuring, the micro LED matrix includes staggered first and second LEDs. The first LEDs are used to emit the first light beam, and the second LEDs are used to emit the second light beam.

[0034] Taking a liquid crystal panel as an example, in order to match the structural characteristics and manufacturing process of the liquid crystal panel, the aforementioned micro LED matrix can be set on the substrate under the display layer of the liquid crystal panel. The micro LED matrix includes staggered ultraviolet LEDs and infrared LEDs to achieve uniform emission of ultraviolet light (first light) and infrared light (second light).

[0035] In other embodiments of the present invention, an independent support layer may also be provided, with the reversible photocurable support structure located on the support layer. Specifically, the above-mentioned flexible display panel includes: a support layer located above the display layer, the support layer including a support area and a non-support area, the support area being perpendicularly corresponding to the pixel gap area of ​​the display layer, and the non-support area being perpendicularly corresponding to the pixel display area of ​​the display layer, the reversible photocurable support structure being located in the support area; and a light emitting device located in the pixel gap area of ​​the display layer, which is a multilayer organic light-emitting device, including a first organic light-emitting layer, a hole injection / transport layer, a first anode layer, a transparent charge generation layer, an electron injection / transport layer, a second organic light-emitting layer, and a second anode layer arranged sequentially from top to bottom, wherein the first organic light-emitting layer is used to emit a first light ray, and the second organic light-emitting layer is used to emit a second light ray.

[0036] Taking an organic electroluminescent panel as an example, to match the structural characteristics and manufacturing process of the organic electroluminescent panel, the light emitting device 3 is a multi-layer organic light emitting device used to emit ultraviolet and infrared light. Since the reversible photocuring support structure is located on the support layer, which is above the display layer, and the light emitting device is located in the pixel gap area of ​​the display layer, meaning the reversible photocuring support structure 2 is located above the light emitting device, light needs to originate from the organic light emitting device and penetrate upwards to trigger the state switching of the reversible photocuring support structure. Ultraviolet light is the core trigger light for the curing of the reversible photocuring support structure and requires the highest possible arrival rate. Ultraviolet light has a wavelength of approximately 365 nm, with high photon energy and weak penetration. If the ultraviolet organic light-emitting layer (the first organic light-emitting layer) is located in the lower layer, it is easily absorbed and attenuated by the organic light-emitting layer and the transparent electrode. Infrared light, on the other hand, is the trigger light for resin reverse curing. It has a wavelength of approximately 800 nm, with low photon energy and extremely strong penetration, and is hardly absorbed by the organic layer or electrode layer. If the infrared organic light-emitting layer (the second organic light-emitting layer) is located in the lower layer, the infrared light can easily penetrate the intermediate transparent charge-generating layer, the ultraviolet organic light-emitting layer, the cathode, and the encapsulation layer, with minimal attenuation. This satisfies the requirements for disulfide bond breaking and resin reverse curing without affecting the crease recovery effect. In summary, to avoid ultraviolet light attenuation, the ultraviolet organic light-emitting layer needs to be as close as possible to the reversible photocurable support structure. Therefore, by placing the ultraviolet organic light-emitting layer directly close to the reversible photocurable support structure, the ultraviolet light only needs to pass through the shared transparent cathode and encapsulation layer, enabling the reversible photocurable support structure to cure instantly when the stress reaches the threshold, forming a rigid support. Simultaneously, the downward-emitted ultraviolet light is completely absorbed by the intermediate transparent charge generation layer and infrared organic light-emitting layer, preventing it from illuminating the underlying thin-film transistor driving layer and PI flexible substrate, thus completely avoiding aging damage to the thin-film transistor driving layer and PI caused by ultraviolet light. Furthermore, the infrared organic light-emitting layer has a low driving voltage (2-3V), while the ultraviolet organic reflective layer has a high driving voltage (5-6V), with the potential increasing from bottom to top, eliminating the risk of potential backflow. Therefore, in this embodiment, the multilayer organic light-emitting device includes, from top to bottom, an ultraviolet organic light-emitting layer, a hole injection / transport layer, a first anode layer, a transparent charge generation layer, an electron injection / transport layer, an infrared organic light-emitting layer, and a second anode layer, arranged sequentially. The multilayer organic light-emitting device is positioned between the visible light emitting areas of two adjacent pixels. By placing the ultraviolet organic light-emitting layer close to the reversible photocurable support structure and the infrared organic light-emitting layer far from it, the light arrival rate is ensured, while reducing aging damage to the thin-film transistor driving layer and PI flexible substrate caused by the first light beam, and avoiding the risk of potential backflow.

[0037] Organic electroluminescent materials require voltage driving. Both the visible light emitting region and the organic electroluminescent materials in the multilayer organic light-emitting device need to be driven and controlled independently. To achieve this, the flexible display panel further includes: a partitioned driving layer disposed below the display layer. The partitioned driving layer includes: a display driving thin-film transistor disposed at a position perpendicular to the pixel display area for driving the pixel display area to emit light; and a dimming driving thin-film transistor disposed at a position perpendicular to the multilayer organic light-emitting device for driving the multilayer organic light-emitting device to emit a first light or a second light. The dimming driving thin-film transistor includes a first dimming driving thin-film transistor and a second dimming driving thin-film transistor, wherein the first dimming driving thin-film transistor is connected to the first anode layer, and the second dimming driving thin-film transistor is connected to the second anode layer.

[0038] Example 3 Figure 2 A structural diagram of a liquid crystal panel provided in an embodiment of this application is shown below. Figure 2 As shown, the liquid crystal panel includes a sensing layer 21, a liquid crystal display layer 22, and a substrate 23. The liquid crystal display layer 22 includes a pixel display area 221 and a pixel gap area 222. The pixel gap area 222 includes a reversible light-curing support structure 222a and a pixel black matrix 222b. A micro LED matrix 231 is disposed on the substrate 23 at a position corresponding to the reversible light-curing support structure 222a. The sensing layer is divided into a protective layer 211, a pressure sensing layer 212, and a conductive connection layer 213. A pressure sensing unit (e.g., a piezoresistor) is disposed in the pressure sensing layer 212.

[0039] The protective layer 211 is a transparent structure, which can prevent dust and dirt and does not affect the light transmission display; the pressure sensing unit (e.g., a pressure-sensitive resistor) only covers the area directly above the pixel gap region 222 (does not cover the pixel display area), and the pressure sensing unit can convert the ambient pressure into a resistance change signal; the conductive connection layer transmits the obtained resistance change signal to the driving chip of the substrate layer, and the conductive lines of the conductive connection layer are distributed in the pixel gap region to avoid obscuring the pixel display area.

[0040] The liquid crystal display layer 22 is divided into a pixel display area 221 and a pixel gap area 222; the pixel display area 221 includes an alignment film, liquid crystal molecules and pixel electrodes; the pixel gap area 222 includes a pixel black matrix 222b and a reversible light-curing support structure 222a.

[0041] The pixel black matrix 222b separates the pixel display areas 221 of adjacent pixels, blocking light crosstalk and creating gaps for the photocurable material. The photocurable material can be a disulfide-bonded reversible photocurable resin. To reduce particle size, the photocurable material can be arranged in groups of 4*4 resin particles, filling the gaps in the pixel black matrix 222b in the bending area to form a reversible photocurable support structure. A transparent encapsulation shell is used to encapsulate the resin particles, preventing leakage. The resin particles have a light transmittance close to that of glass and are colorless and transparent. Even after curing, they do not change the light transmittance characteristics of the liquid crystal layer, effectively adding an "invisible transparent support" within the pixel gaps, without affecting the display.

[0042] The liquid crystal display layer uses PI as a substrate, carrying liquid crystal molecules and resin, and isolating the LEDs and pixel electrodes of the substrate. The substrate consists of a PI substrate, an insulating conductive layer, a thin-film transistor driving circuit, a micro LED matrix, and a driving chip. The PI substrate provides flexible support and can withstand a certain degree of bending; the insulating conductive layer isolates the circuit and transmits signals; the thin-film transistor driving circuit is located directly below the pixel display area, driving the pixel electrodes to control pixel display; the micro LED matrix 231 is located directly below the pixel gap area 222, aligned with the reversible photocurable support structure composed of resin particles, with one micro LED matrix corresponding to one reversible photocurable support structure. The micro LED matrix consists of alternating ultraviolet and infrared LEDs to ensure uniform distribution when the ultraviolet / infrared LEDs are triggered.

[0043] The driver chip is located at the edge of the substrate, receives the pressure signal from the sensing layer, determines the pressure level, and triggers the ultraviolet / infrared LED beads to light up.

[0044] During the folding to flattening process, the flexible display panel undergoes the following process: folding - increased bending stress - conversion of bending stress signal into electrical signal - triggering the light emitting device to emit ultraviolet light - reversible light curing support structure curing - rigid anti-folding - flattening - decreased bending stress - conversion of bending stress signal into electrical signal - triggering the light emitting device to emit infrared light - reversible light curing support structure reverse curing - restoration of flexibility - crease repair.

[0045] The flexible liquid crystal display panel in this embodiment will go through the following working states: I. Normal working status.

[0046] When the flexible LCD panel is laid flat and not bent, the pressure sensing unit has no signal output, the micro LED matrix does not work, the photocurable resin particles are in a liquid state, the flexible LCD panel displays normally, and maintains its flexibility.

[0047] II. Rigid anti-bending state.

[0048] When a flexible LCD panel is bent, the bending stress is transmitted to the pressure sensing layer. The pressure sensing unit deforms due to the force, and its resistance changes with the bending stress. The changing resistance signal is transmitted to the driving chip on the substrate through the conductive connection layer. The driving chip triggers the infrared LEDs in the corresponding stress area's micro LED matrix to remain in a non-lit state, while the ultraviolet LEDs light up briefly. By irradiating the reversible photocurable support structure in the pixel gap with ultraviolet light, the photocurable resin particles undergo a cross-linking reaction under ultraviolet light excitation, changing from a liquid state to a solid state. The photocurable resin particles are constrained by the pixel black matrix and the upper and lower substrates to form a rigid support structure, enabling the panel to meet the normal hardness requirements, resist bending stress, prevent plastic deformation of the substrate and display layer, and avoid creases at the source.

[0049] III. Recovery status of creases and folds When the flexible liquid crystal display panel returns to its flat state, the bending stress disappears, the deformation of the pressure sensing layer rebounds, the resistance value of the pressure sensing unit returns to its initial state, and the driver chip receives the signal and determines that the flexible liquid crystal display panel has returned to its flat state. It then controls the ultraviolet lamps in the micro lamp matrix to turn off and the infrared lamps to light up briefly, emitting infrared light. This causes the disulfide bonds in the photocurable resin molecules to break appropriately, thereby causing the photocurable resin particles to return from a solid state to a liquid state and releasing the rigid support.

[0050] IV. Daily crease recovery status.

[0051] The standard elastic deformation curves corresponding to different stresses in a crease-free state of the panel can be pre-calibrated. The current stress value is collected through the pressure sensing layer, and the deformation of the current flexible liquid crystal display panel is determined. If the deformation is much greater than the standard elastic deformation under the same stress, or if the deformation does not recover to the reference value after the stress is reduced to zero, i.e., the residual deformation is ≥ a preset threshold (e.g., 5%), it is determined to be a crease feature. A crease generation signal is then generated and transmitted to the driver chip. After receiving the crease generation signal, the driver chip triggers the ultraviolet lamps in the micro-LED matrix in the crease area to turn off, while the infrared lamps remain lit for a period of time, allowing the photocurable resin to fully reverse cure. The infrared light irradiates the resin particles in the reversible photocurable support structure of the crease area, causing all the disulfide bonds to break completely, and the resin to completely reverse cure into a liquid state. The crease area of ​​the flexible liquid crystal display panel loses its rigid support and softens. After softening, the crease area of ​​the flexible liquid crystal display panel can complete deformation recovery with the assistance of external force or its own substrate rebound characteristics, eliminating the crease.

[0052] It should be noted that the stress level mentioned above is the trigger condition for preventing creases beforehand. That is, when the bending stress exceeds a certain threshold, the resin immediately solidifies to form a rigid support, thus preventing creases from forming at the source. The crease characteristics mentioned above are the trigger conditions for repairing creases afterward. When the panel has already undergone permanent plastic deformation, i.e., a crease, even if the stress disappears, the deformation cannot rebound. At this time, it is necessary to identify the crease characteristics to determine whether a crease has occurred, and then trigger crease repair.

[0053] The aforementioned flexible display panel utilizes visible light with wavelengths of 400-760nm. Ultraviolet / infrared light is not within the display band of this flexible display panel and will not interfere with the display effect.

[0054] Example 4 Figure 3 A structural diagram of an organic electroluminescent panel provided in an embodiment of this application is shown below. Figure 3 As shown, the organic electroluminescent panel includes a sensing layer 31, a support layer 32, a dual-zone light-emitting layer 33 (i.e., the aforementioned display layer), a partitioned driving layer 34, and a substrate 35. The dual-zone light-emitting layer 33 includes a pixel display area 331 and a pixel gap area 332. A reversible light-curing support structure 321 is disposed within the support layer 32 above the dual-zone light-emitting layer 33, at a position corresponding to the pixel gap area 332. A pixel black matrix 322 is disposed above the pixel display area 331, corresponding to the edge above the pixel gap area 332, and surrounds the reversible light-curing support structure 321. A multilayer organic light-emitting device 333 is disposed in the pixel gap area 332 at a position corresponding to the reversible light-curing support structure 321.

[0055] Figure 4 A structural diagram of a multilayer organic light-emitting device in an organic electroluminescent panel provided in this application is shown below. Figure 4 As shown, the multilayer organic light-emitting device 333 includes: an ultraviolet organic light-emitting layer 333a, a hole injection / transport layer 333b, a first anode layer 333c, a transparent charge generation layer 333d, an electron injection / transport layer 333e, an infrared organic light-emitting layer 333f, and a second anode layer 333g, wherein the second anode layer 333g is shared with the pixel display area 331.

[0056] Partition driver layer 34 is divided into two partitions on the same plane: The thin-film transistor area is located directly below the OLED pixel display area 331, driving the OLED pixel display area 331 to emit visible light and ensuring normal display effect.

[0057] The dimming thin-film transistor region is located directly below the multilayer organic light-emitting device 333, perpendicularly corresponding to the pixel gap region 332. Two independent dimming thin-film transistors are fabricated in the same layer: an infrared dimming thin-film transistor and an ultraviolet dimming thin-film transistor. These are connected to the two anodes of the pixel gap region 332, respectively, and are responsible for the independent driving of the ultraviolet organic light-emitting layer 333a and the infrared organic light-emitting layer 333f. The two types of thin-film transistors are physically isolated by an interlayer insulating layer. The wiring is arranged along the pixel gap without obstructing the display. The driving signals are independently isolated, and the display driving and dimming driving are implemented by two independent control modules of the same driving chip, without interference.

[0058] The first anode layer 333c is connected to the ultraviolet (UV) dimming thin-film transistor (TFT), and the second anode layer 333g is connected to the infrared (IR) dimming thin-film transistor (TFT). The IR OLED layer 333f and the UV OLED layer 333a can share a cathode with the pixel display area 331. The first anode layer 333c corresponds to the UV OLED layer 333a. The UV OLED layer 333a is independently driven to emit light through the first anode layer 333c, thus curing the reversible photocurable support structure 321. The second anode layer 333g corresponds to the IR OLED layer 333f. The IR OLED layer 333f is independently driven to reverse-cur the reversible photocurable support structure 321 through the second anode layer 333g.

[0059] The transparent charge generation layer 333d (CGL) separates the infrared organic light-emitting layer 333f and the ultraviolet organic light-emitting layer 333a, avoiding crosstalk between the driving signals of the two layers and ensuring that their driving voltages are independent. The transparent charge generation layer 333d can generate electron-hole pairs, providing charge injection for the two independent organic light-emitting layers respectively, without the need to increase the driving voltage, thus ensuring the luminous efficiency and lifetime of the two layers. The transparent charge generation layer 333d uses n-type / p-type doped transparent organic / inorganic materials, which have no visible light absorption and high infrared / ultraviolet transmittance, without affecting light transmission and display effects.

[0060] The dual-zone light-emitting layer 33 is an organic light-emitting thin film, on which two independently driven pixelated OLED regions are divided: pixel display region 331 and pixel gap region 332.

[0061] The pixel display area 331 adopts the RGB sub-pixel array of the OLED display standard. Each sub-pixel is an independent visible light OLED light-emitting unit that emits red / green / blue visible light (400-760nm) to achieve normal image display. The pixel gap area 332 is set at the corresponding position above the edge. The pixel black matrix in four directions forms an enclosing groove. The reversible light-curing support structure is precisely set in the groove enclosed by the pixel black matrix.

[0062] Within the non-pixel display area enclosed by the pixel black matrix in each pixel gap region 332, a multi-layer organic light-emitting device 333 is set. The infrared organic light-emitting layer 333f is located on the side near the partition driving layer 34 (bottom), and the ultraviolet organic light-emitting layer 333a is located on the side near the reversible photocurable support structure 321 (top). The multi-layer organic light-emitting device 100% covers the photocurable material within the gap. This is a subdivided design within the pixel gap region. It does not change the overall planar thin film morphology of the dual-zone light-emitting layer 33. It can emit 365nm ultraviolet light and 800nm ​​infrared light. It is only used to trigger the state switching of the photocurable support material within the pixel gap and does not participate in the display. There is no visible light emission.

[0063] The reason why the infrared organic light-emitting layer 333f is closer to the partitioned driving layer 34 (bottom) and the ultraviolet organic light-emitting layer 333a is closer to the reversible light-curing support structure 321 (top) is as follows: Since the reversible photocurable support structure 321 is located on top of the light emitting device, light needs to originate from the organic light-emitting layer and penetrate upwards to trigger the state switching of the reversible photocurable support structure 321. Ultraviolet light is the core trigger light for the curing of the reversible photocurable support structure 321, and it needs to have the highest possible arrival rate. The wavelength of ultraviolet light is about 365nm, with high photon energy and weak penetration. If the ultraviolet organic light-emitting layer 333a is placed in the lower layer, it is easily absorbed and attenuated by the organic light-emitting layer and transparent electrode. Infrared light is the trigger light for resin reverse curing, with a wavelength of about 800nm, low photon energy, and extremely strong penetration. It is hardly absorbed by the organic layer or electrode layer. If the infrared organic light-emitting layer 333f is placed in the lower layer, the infrared light can easily penetrate the intermediate transparent charge generation layer 333d, ultraviolet organic light-emitting layer 333a, cathode, and encapsulation layer with low attenuation. This can meet the requirements for disulfide bond breaking and resin softening without affecting the crease recovery effect. In summary, to avoid UV light attenuation, the UV organic light-emitting layer 333a needs to be as close as possible to the reversible photocurable support structure 321. Therefore, the UV organic light-emitting layer 333a is directly attached to the reversible photocurable support structure 321. The UV light only needs to pass through the shared transparent cathode and encapsulation layer, which can solidify the reversible photocurable support structure 321 instantly when the stress reaches the threshold, forming a rigid support. At the same time, the downward-emitted UV light is completely absorbed by the intermediate transparent charge generation layer 333d and infrared organic light-emitting layer 333f, and will not irradiate the underlying thin-film transistor driving layer and PI flexible substrate, thus completely avoiding UV attenuation. The aging damage to the thin-film transistor driving layer and the PI flexible substrate is mitigated. Furthermore, the infrared organic light-emitting layer 333f has a low driving voltage (2-3V), while the ultraviolet organic reflective layer has a high driving voltage (5-6V). The potential increases from bottom to top, eliminating the risk of potential backflow. Therefore, the aforementioned multilayer organic light-emitting device includes, from top to bottom, an ultraviolet organic light-emitting layer 333a, a hole injection / transport layer, a first anode layer 333c, a transparent charge generation layer 333d, an electron injection / transport layer, an infrared organic light-emitting layer 333f, and a second anode layer 333g. The multilayer organic light-emitting device is positioned between the visible light emitting areas of two adjacent pixels. By placing the ultraviolet organic light-emitting layer 333a close to the reversible photocurable support structure 321 and the infrared organic light-emitting layer 333f away from the reversible photocurable support structure 321, the light arrival rate is ensured, while reducing the aging damage of ultraviolet light to the thin-film transistor driving layer and the PI flexible substrate, and avoiding the risk of potential backflow.

[0064] The dual-zone emitting layer 33 adopts a planar partitioned differentiated structure: the pixel display area 331 is a single-layer RGB visible light OLED emitting layer; the pixel gap area 332 is a local stacked structure. In the same plane, only in the pixel gap area 332 is a stacked structure of "infrared organic emitting layer 333f-transparent charge generation layer 333d-ultraviolet organic emitting layer 333a". The transparent charge generation layer 333d is deposited separately in the pixel gap area 332 through a high-precision mask, without completely covering the pixel display area 331. This achieves a partitioned design of single-layer pixel display area and stacked pixel gap area, which ensures the display performance of pixel display area and covers the emitting area of ​​pixel gap area.

[0065] The folding and unfolding process of an organic electroluminescent panel involves the following steps: 1. Flexible Display under Normal Conditions: The multi-layer organic light-emitting device does not emit light, the photocurable support material is liquid, the OLED panel remains flexible, and can be folded / bent normally without affecting the display function.

[0066] 2. Bending stress triggering, rigid anti-folding: When the sensing layer 31 detects bending stress ≥ threshold (such as 180° folding stress in the hinge area of ​​the folding screen), the dimming thin film transistor drives the ultraviolet organic light-emitting layer 333a in the pixel gap area 332 to light up briefly. The resin quickly solidifies into a solid support pillar to resist bending stress and avoid plastic deformation of the OLED panel substrate / light-emitting layer, thus preventing creases from the source.

[0067] III. Stress Disappearance and Restoration of Flexibility: After the bending stress is relieved, the dimming thin-film transistor drives the infrared organic light-emitting layer 333f to light up, the photocurable support material undergoes reverse curing, the panel regains its flexibility, and does not affect subsequent folding use; IV. Crease Recognition and Active Recovery: If the panel has a permanent crease (residual deformation ≥ threshold after stress returns to zero), the sensing layer 31 accurately locates the crease area. The dimming thin film transistor driver can also drive the infrared organic light-emitting layer 333f to be lit at high power for a long time, so that the resin is fully softened. With the help of its own flexible substrate, the organic electroluminescent panel completes the crease reset and restores flatness. Moreover, the operation only targets the crease area and does not affect the display of other areas.

[0068] The ultraviolet / infrared bands emitted by the multilayer organic light-emitting device are completely isolated from the visible light bands (400-760nm) displayed by the organic electroluminescent panel; the reversible light-curing support structure 321 and the sensing layer 31 are both designed with high transparency, without any display obstruction.

[0069] Example 5 This embodiment provides a foldable device, including the flexible display panel described in the above embodiment.

[0070] 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 mean including 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.

[0071] 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 flexible display panel, characterized in that, The flexible display panel includes a display layer, the display layer including a pixel display area and a pixel gap area, the pixel gap area being located around the pixel display area, and the flexible display panel further includes: A reversible light-curing support structure, the projection of which falls into the pixel gap area; the reversible light-curing support structure is cured under the irradiation of a first light and reverse-cured under the irradiation of a second light. A light emitting device is positioned perpendicularly to the reversible photocurable support structure. It is used to emit a first light when the flexible display panel is in a bent state to cure the reversible photocurable support structure, and to emit a second light when the flexible display panel returns to a flat state to reverse the curing of the reversible photocurable support structure. The first ray is ultraviolet light, and the second ray is infrared light.

2. The flexible display panel according to claim 1, characterized in that, The reversible photocurable support structure includes multiple photocurable resin particles, and the outer layer of the photocurable resin particles is covered with a closed transparent shell.

3. The flexible display panel according to claim 2, characterized in that, The structural formula of the photocurable resin is: ； Wherein, the R basis can be any of the following: ; ; 。 4. The flexible display panel according to claim 1, characterized in that, The flexible display panel also includes: A sensing layer, disposed on the display layer, is used to detect the bending stress in the bending area of ​​the flexible display panel, and to determine whether the flexible display panel is in a bent or flat state based on the bending stress data.

5. The flexible display panel according to claim 4, characterized in that, The sensing layer includes a protective layer, a pressure sensing layer, and a conductive connection layer arranged sequentially from top to bottom; The protective layer is a transparent structure; The pressure sensing layer includes uniformly distributed pressure sensing units, and the distribution area of ​​the pressure sensing units corresponds perpendicularly to the pixel gap area. The conductive connection layer includes conductive lines, and the distribution area of ​​the conductive lines corresponds perpendicularly to the pixel gap area.

6. The flexible display panel according to claim 1, characterized in that, The reversible photocurable support structure is embedded in the pixel gap region of the display layer; The light emitting device includes a matrix of miniature LED beads, which includes first and second LED beads arranged in an alternating pattern. The first LED beads are used to emit a first light beam, and the second LED beads are used to emit a second light beam.

7. The flexible display panel according to claim 1, characterized in that, The flexible display panel includes: A support layer is located above the display layer. The support layer includes a support area and a non-support area. The support area is perpendicularly corresponding to the pixel gap area of ​​the display layer, and the non-support area is perpendicularly corresponding to the pixel display area of ​​the display layer. The reversible light-curing support structure is located in the support area. The light emitting device is a multilayer organic light-emitting device, comprising, from top to bottom, a first organic light-emitting layer, a hole injection / transport layer, a first anode layer, a transparent charge generation layer, an electron injection / transport layer, a second organic light-emitting layer, and a second anode layer, wherein the first organic light-emitting layer is used to emit a first light ray, and the second organic light-emitting layer is used to emit a second light ray.

8. The flexible display panel according to claim 7, characterized in that, The flexible display panel further includes: a partition driving layer disposed below the display layer, the partition driving layer comprising: A display driving thin-film transistor is disposed at a position perpendicular to the pixel display area and is used to drive the pixel display area to emit light; A dimming driving thin-film transistor is disposed at a position perpendicular to the multilayer organic light-emitting device, and is used to drive the multilayer organic light-emitting device to emit a first light or a second light. The dimming driving thin-film transistor includes a first dimming driving thin-film transistor and a second dimming driving thin-film transistor, wherein the first dimming driving thin-film transistor is connected to the first anode layer, and the second dimming driving thin-film transistor is connected to the second anode layer.

9. A foldable device, characterized in that, Includes the flexible display panel according to any one of claims 1 to 8.

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