CN109346504B

CN109346504B - Flexible display panel and display device

Info

Publication number: CN109346504B
Application number: CN201811162024.1A
Authority: CN
Inventors: 胡江平; 崔永鑫
Original assignee: Yungu Guan Technology Co Ltd
Current assignee: Yungu Guan Technology Co Ltd
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2021-06-29
Anticipated expiration: 2038-09-30
Also published as: CN109346504A

Abstract

The invention relates to a flexible display panel, which is provided with a plurality of pixel island regions separated from each other and flexible regions arranged between the adjacent pixel island regions; the flexible display panel further includes a cathode electrode including island patterns formed at the corresponding pixel island regions, and a plurality of bridge patterns connecting adjacent island patterns to each other. Above-mentioned flexible display panel through set up the cathodic film layer into the bridging pattern of a plurality of island patterns and connection adjacent island pattern, makes the screen body when tensile or buckle, and island pattern can form the module that flows to avoid cathodic film layer to take place fracture or damage, and then improved the stress and the ductility of cathodic film layer. A display device is also provided.

Description

Flexible display panel and display device

Technical Field

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

Background

In recent years, with the development of society and the advancement of science and technology, the technical development of intelligent terminal devices and wearable devices is changing day by day, the requirements for flat panel display are gradually increased, and the requirements are more and more diversified. Since an OLED (Organic Light-Emitting Diode) display device has the advantages of lower power consumption, higher brightness and response speed, better flexibility and better flexibility compared with a liquid crystal display, the OLED display device is more and more widely applied to smart terminal products such as mobile phones, tablet computers, and even televisions, and becomes a mainstream display in the display field.

Meanwhile, the demands of users for display devices of electronic devices tend to be more diversified, and stretchable display devices, which are one of the important development directions of display devices, are receiving more and more attention. In practical use, the stretchable display device needs to be stretchable in at least one direction, but in bending or stretching, a display defect such as black spots or no display is likely to occur in a partial region.

Therefore, how to improve the stretchability and the bendability of the stretchable display device is a technical problem to be solved in the art.

Disclosure of Invention

Accordingly, it is desirable to provide a flexible display panel and a display device that can improve the above-mentioned problems, in order to solve the problem that the display defects are likely to occur during the stretching or bending process of the stretchable display device in the conventional design.

A flexible display panel having a plurality of pixel island regions spaced apart from each other, and a flexible region disposed between adjacent pixel island regions;

the flexible display panel further includes a cathode electrode including island patterns formed at the corresponding pixel island regions, and a plurality of bridge patterns connecting adjacent island patterns to each other.

Above-mentioned flexible display panel through set up the cathodic film layer into the bridging pattern of a plurality of island patterns and connection adjacent island pattern, makes the screen body when tensile or buckle, and island pattern can form the module that flows to avoid cathodic film layer to take place fracture or damage, and then improved the stress and the ductility of cathodic film layer.

Optionally, one of the island patterns corresponds to one of the pixel island regions.

Optionally, the island pattern has a stiffness greater than a stiffness of the bridge pattern.

Optionally, a thickness of the island pattern is greater than a thickness of the bridge pattern.

Optionally, the bridge pattern has at least one convex portion and/or at least one concave portion in a direction perpendicular to the flexible display panel.

Alternatively, the recess is a trench formed between two adjacent island patterns.

Optionally, the cathode comprises a first cathode layer and a second cathode layer;

the first cathode layer is formed in the corresponding pixel island region;

the second cathode layer is formed on the first cathode layer; the second cathode layer is formed on the pixel island region to form the island pattern; the second cathode layer is also formed on the flexible region to constitute the bridge pattern connecting the island patterns adjacent to each other.

Optionally, the first cathode layer is the same material as the second cathode layer;

preferably, the first cathode layer and the second cathode layer are made of magnesium-silver alloy.

Optionally, the bridge pattern partially covers the flexible region; or

The bridge pattern covers the flexible area entirely.

A flexible display panel comprising:

a flexible substrate including a plurality of islands spaced apart from each other, and a plurality of bridges connecting adjacent ones of the islands;

display units respectively arranged on the plurality of islands; and

and a cathode including island patterns formed on the corresponding islands, and a plurality of bridge patterns formed on the bridges for connecting the adjacent island patterns to each other.

A display device comprising the flexible display panel described in the above embodiments.

According to the invention, the cathode film layer is provided with a plurality of island patterns and bridging patterns for connecting adjacent island patterns, so that the island patterns can form flowing modules when the screen body is stretched or bent, thereby preventing the cathode film layer from being broken or damaged, and further improving the stress and ductility of the cathode film layer.

Drawings

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

FIG. 2 is a schematic structural diagram of a cathode according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of the cathode shown in fig. 2.

Detailed Description

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

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

In describing positional relationships, when an element such as a layer, film or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present, unless otherwise specified. Further, when a layer is referred to as being "under" another layer, it can be directly under, or one or more intervening layers may also be present. It will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention.

It will also be understood that when interpreting elements, although not explicitly described, the elements are to be interpreted as including a range of errors which are within the acceptable range of deviation of the particular values as determined by those skilled in the art. For example, "about," "approximately," or "substantially" may mean within one or more standard deviations, without limitation.

Further, in the specification, the phrase "plane distribution diagram" refers to a drawing when the target portion is viewed from above, and the phrase "sectional diagram" refers to a drawing when a section taken by vertically cutting the target portion is viewed from the side.

Furthermore, the drawings are not 1: 1, and the relative dimensions of the various elements in the figures are drawn for illustration only and not necessarily to true scale.

With the rapid development of OLED display panel technology, OLED display panels have the characteristics of flexibility and good flexibility, and therefore OLED display panels have a great advantage of being made into foldable, rollable or stretchable products compared to the conventional TFT-LCD technology.

For a flexible display panel, the flexible display panel generally includes a plurality of gate lines and a plurality of data lines arranged on a flexible substrate in a crossing manner, and the gate lines and the data lines enclose display units arranged in a matrix. Each display unit has a TFT (Thin-film transistor) structure, an OLED (Organic Light-Emitting Diode) structure, and a corresponding driving circuit, and thus has the characteristics of high pixel density and dense wiring. Therefore, the flexible display panel is stretchable/bendable and is prone to poor display.

Each sub-pixel is controlled to emit light or not by the TFT structure, each sub-pixel corresponds to an anode, and a cathode covers the flexible substrate to provide electrons for the OLED light-emitting device. Generally, the cathode is a more electron-donating, alloyed cathode formed using a metal with a low power function, or a metal with a low power function and a high power function that is chemically stable. For example, the material can be made of metals with lower power function, such as silver, lithium, magnesium, calcium, strontium, aluminum, indium, etc., or metal compounds or alloy materials.

However, research shows that, limited by the development of materials, the cathode film layer in the existing design has insufficient stress and extensibility during the bending and stretching process of the display panel, so that the cathode film layer is damaged during the stretching or bending process of the screen body, and the corresponding pixels cannot display.

Therefore, it is desirable to provide a flexible display panel with improved tensile and bending properties by increasing the stress and ductility of the cathode film.

In the embodiment of the invention, the cathode film layer is provided with a plurality of island patterns and bridging patterns for connecting adjacent island patterns, so that the island patterns can form flowing modules when the screen body is stretched or bent, the cathode film layer is prevented from being broken or damaged, and the stress and the ductility of the cathode film layer are improved.

Hereinafter, a display panel in an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a schematic structural diagram of a flexible display panel in an embodiment of the invention; FIG. 2 shows a schematic structural diagram of a cathode in an embodiment of the invention; FIG. 3 shows a cross-sectional view of the cathode shown in FIG. 2; for the purpose of illustration, the drawings show only the structures associated with embodiments of the invention.

Referring to the drawings, the flexible display panel 10 has a plurality of pixel island regions 12 separated from each other, and a flexible region 14 disposed between adjacent pixel island regions 12. Specifically, the pixel island region 12 is a rigid region serving as an effective display region of the display panel, and the flexible region 14 is a stretchable or bendable region.

In some embodiments, one or more display units (not shown) as an effective display area may be disposed in each pixel island area 12, and connection lines and data lines connecting adjacent pixel island areas 12 are disposed in the flexible area 14.

For example, in particular to some embodiments, a display panel includes a flexible substrate that may include a plurality of islands spaced apart from one another, and bridges connected between adjacent islands. The plurality of islands may be spaced apart from each other by a predetermined gap and may have flat upper surfaces, and the display cells as the effective display areas are respectively disposed over the flat upper surfaces of the respective islands.

The plurality of islands and the plurality of bridges may be integrally formed, and the flexible substrate may be formed of an organic material having elasticity and ductility, such as Polyimide (PI), but of course, the flexible substrate is not limited to polyimide and may include various other materials having elasticity and ductility.

It will be readily appreciated that in some embodiments, the bridge may fill the flexible region 14 between adjacent islands, that is, the islands may be similar to a plurality of spaced apart bumps formed on the flexible substrate. In other embodiments, the bridges between adjacent islands are further spaced to form a plurality of hollowed-out areas, and the bridges may extend in a plane along a straight line or a curve to connect adjacent islands. For example, each of the plurality of bridges may extend in a plane along an S-bend, and further, the flexible substrate may be a unitary body having a mesh pattern. Thus, the flexible substrate has high flexibility.

It is understood that in other embodiments, an elastic layer may be disposed on the bridge to improve the flexibility of the flexible substrate, and is not limited herein.

Due to the flexible regions 14 between the islands of the flexible substrate, the flexible regions 14 may be stretch-deformed when an external force is applied to the display panel, e.g., the plurality of bridges may change their shape and increase their length in response to the external force and may return to their original shape when the external force is removed. In this way, the gaps between the plurality of islands may be changed, the flexible substrate may change its shape two-dimensionally or three-dimensionally, and the shape of the islands may be maintained during the stretching or bending process, so that the display units located on the islands may not be damaged, and thus the flexible display panel 10 may have a stretching or bending function.

Metal wirings (lines of a power supply voltage, a data signal, a scan signal, and the like) may be respectively disposed on the plurality of bridges and electrically connected to the display unit. As a preferred embodiment, an insulating layer may be further provided on the metal wiring to prevent the metal wiring from being exposed. In particular, in one embodiment, the insulating layer may cover the bridge over its entire surface, that is to say have the same shape as the bridge.

The display cells are disposed on the respective islands and may include a TFT array structure (thin film transistor) and an OLED structure electrically connected to the TFT array structure. The display unit may include a display area and a non-display area surrounding the display area. For example, each display unit may include a pixel emitting at least one of red light, blue light, green light, or white light, the pixel being disposed in the display region.

In some embodiments, a buffer layer may be disposed on the islands of the flexible substrate, the buffer layer providing a planar surface on the islands and may comprise a suitable material such as PET, PEN polyacrylate, and/or polyimide, forming a layered structure in a single layer or a multi-layer stack. A single-layer or multi-layer stacked layered structure may also be formed of silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, titanium oxide, or titanium nitride, or may include a composite layer of an organic material layer and/or an inorganic material.

The thin film transistor is arranged above the buffer layer. The emission of each pixel may be controlled or the amount of emission at which each pixel emits may be controlled. In some embodiments, the thin film transistor may be a top gate type in which a semiconductor layer (active layer), a gate electrode, a source electrode, and a drain electrode are sequentially formed, but may be any other type in other embodiments, for example, a bottom gate type.

The semiconductor layer may be formed of an amorphous silicon layer, a metal oxide, or a polysilicon layer, or may be formed of an organic semiconductor material. In some embodiments, the semiconductor layer includes a channel region and source and drain regions doped with a dopant.

The semiconductor layer may be covered with a gate insulating layer, and the gate electrode may be disposed on the gate insulating layer. In general, the gate insulating layer may cover the entire surface of the base substrate. In some embodiments, the gate insulating layer may be formed by patterning. The gate insulating layer may be formed of silicon oxide, silicon nitride, or other insulating organic or inorganic materials in consideration of adhesion to adjacent layers, formability of a stack target layer, and surface flatness. The gate electrode may be covered by an interlayer insulating layer formed of silicon oxide, silicon nitride, and/or other suitable insulating organic or inorganic materials. A portion of the gate insulating layer and the interlayer insulating layer may be removed, and a contact hole may be formed after the removal to expose a predetermined region of the semiconductor layer. The source and drain electrodes may contact the semiconductor layer via the contact holes.

A passivation layer may be formed to cover the thin film transistor, the passivation layer removing a stepped portion generated by the thin film transistor and planarizing a surface of the thin film transistor, thereby preventing the OLED from having a defect due to the unevenness. In some embodiments, the passivation layer may be a single layer or multiple layers of a film formed of an organic material. The organic material illustratively includes general-purpose polymers such as polymethylmethacrylate, polystyrene, and also may be a mixture of polymer derivatives having a phenol-based group, acryl-based polymers, imide-based polymers, aryl ether-based polymers, and the like.

It is to be understood that the passivation layer may also be a composite stacked structure of an inorganic insulating film and an organic insulating film.

In some embodiments, the OLED structure may include a first electrode, a second electrode 16 facing the first electrode, and an intermediate layer between the first electrode and the second electrode 16. In an embodiment, the first electrode may be an anode, the second electrode 16 may be a cathode, and the first electrode is electrically connected to the drain electrode of the TFT by forming a contact hole in the passivation layer.

The first electrode may be a transparent electrode, a translucent electrode, or a reflective electrode. For example, when the first electrode is a transparent electrode, the first electrode may comprise Indium Tin Oxide (ITO), indium zinc oxide, indium sesquioxide, indium potassium oxide, aluminum zinc oxide, or the like, for example. When the first electrode is a reflective electrode, it may include silver, magnesium, aluminum, platinum, gold, nickel, and the like. The second electrode 16 may be a transmissive electrode, and may be made of a metal with a low power function, such as silver, lithium, magnesium, calcium, strontium, aluminum, indium, or a metal compound or alloy material.

The intermediate layer includes at least an organic light emitting layer, which may be formed of a low molecular organic material or a polymer organic material. In some embodiments, the intermediate layer may further include functional film layers such as a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer.

In an embodiment, the hole injection layer may be made of a radical emitting material, so that the hole injection layer, the first electrode and the hole transport layer have better energy level matching, the hole injection capability is effectively improved, and the performance of the organic electroluminescent display panel is further improved. Of course, the material of the hole injection layer includes, but is not limited to, a radical emitting material, such as HAT-CN. The material of the electron injection layer can be lithium fluoride, lithium oxide, lithium boron oxide, potassium silicate, cesium carbonate, and metal acetates.

In the preferred embodiment, each film structure of the intermediate layer of the OLED can be formed by evaporation, thereby improving the performance of the organic electroluminescent device.

It is emphasized that, in some embodiments, the stacking order of the electron injection layer and the electron transport layer, and the stacking order of the hole injection layer and the hole transport layer may be determined according to actual situations, for example, the electron injection layer may be located on a side of the electron transport layer away from the organic light emitting layer, or may be located between the electron transport layer and the organic light emitting layer.

The encapsulation layer is arranged on the side of the second electrode 16 facing away from the flexible substrate. It is easily understood that since the organic light emitting material layer is sensitive to external environments such as moisture and oxygen, if the organic light emitting material layer in the display panel is exposed to moisture or oxygen, the performance of the display panel may be drastically reduced or completely damaged. The packaging layer can block air and water vapor for the organic light-emitting unit, so that the reliability of the display panel is ensured.

It is understood that, for the flexible display panel 10, the encapsulation layer may be a thin film encapsulation layer, wherein the thin film encapsulation layer may be one or more layers, an organic film layer or an inorganic film layer, or a stacked structure of an organic film layer and an inorganic film layer. For example, in some embodiments, the thin film encapsulation layer may include two inorganic film layers and an organic film layer disposed between the two inorganic film layers.

In some embodiments, the display unit further includes a pixel defining layer formed on the passivation layer and exposing at least a portion of each of the first electrodes. For example, the pixel defining layer may cover at least a portion of an edge of each of the first electrodes, thereby exposing at least a portion of each of the first electrodes. Thus, the pixel defining layer defines a plurality of pixel defining openings and a spacing region (not shown) between the pixel defining openings, and a middle portion or a whole portion of the first electrode is exposed through the pixel defining openings.

In this way, the pixel defining layer can increase the distance between the end portion of each first electrode and the opposite electrode (second electrode 16) formed on each first electrode, and can prevent antireflection from occurring at the end portion of the first electrode.

It is understood that the light emitting principle of an OLED is that a semiconductor material and an organic light emitting material emit light by carrier injection and recombination under electric field driving. Specifically, under a certain voltage driving, electrons and holes are injected from the second electrode 16 and the first electrode respectively to the organic light emitting layer of the intermediate layer, and are recombined therein to form excitons and excite the light emitting molecules, which emit visible light through radiative relaxation. In the prior art, each pixel is controlled to emit light or not by the TFT array circuit, each pixel corresponds to a first electrode, and the second electrode 16 covers the entire surface of the pixel defining layer to provide electrons for the OLED light emitting device. Therefore, the second electrode 16 covered over the entire surface is likely to cause film breakage during the stretching or bending of the display panel, or the electron injection layer and the cathode are likely to be separated from each other, resulting in poor display.

In an embodiment of the present invention, the cathode electrode includes island patterns 162 formed at corresponding pixel island regions 12, and a plurality of bridge patterns 164 connecting adjacent island patterns 162 to each other. For example, as a preferred embodiment, each of the plurality of island patterns 162 may correspond to one pixel island region 12.

Thus, when the screen body is stretched or bent, the island pattern 162 of the cathode can move along with the islands of the flexible substrate to form a flow module, so that the shape and the size are stable, and the shape and the length of the bridge pattern 164 are changed. Since the bridge patterns 164 are disposed in the flexible region 14 and have a smaller area than the island patterns 162, the risk of breaking or damaging the film caused by stress is reduced, and the stress and ductility of the cathode film are improved.

In addition, the island pattern 162 is stably disposed on the island of the flexible substrate, thereby preventing the island pattern from being separated from the film layer of the electron injection layer, and further improving the stretchability and the bendability of the display panel.

It is understood that, in other embodiments, each of the plurality of island patterns 162 may correspond to a plurality of pixel island regions 12, which is not limited herein. For example, in the stretched or bent region of the display panel, the cathode island pattern 162 may be associated with the pixel island regions 12 one by one, and in other regions of the display panel, one cathode island pattern 162 may be associated with a plurality of pixel island regions 12. Therefore, the difficulty of the patterning process can be reduced, the production cost is reduced, and the stretchability and the bendability of the display panel are not influenced.

It is also understood that the bridge pattern 164 may partially cover the flexible region 14 or may completely cover the flexible region 14. For example, in some embodiments, the islands are protrusions formed on the flexible substrate, gaps are formed between adjacent islands, the gap regions are the flexible regions 14, and the bridging patterns 164 may partially cover the flexible regions 14 to reduce the influence of the stress generated during the stretching or bending process of the flexible substrate on the bridging patterns 164 of the cathode. Further, it is also possible to play a role in releasing stress by changing the length and shape of the bridge pattern 164, for example, the bridge pattern 164 is configured to extend in a zigzag shape with a uniform or non-uniform width.

In other embodiments, the flexible substrate may include a plurality of islands and bridges connected between the islands, and the bridges have a plurality of hollowed-out portions therebetween, for example, the flexible substrate is in a grid shape, and the bridges may also extend in a plane along a straight line or a curve. The bridge pattern 164 is configured to overlie the bridge, that is, the bridge pattern 164 entirely overlies the flexible region 14. In this manner, the bridge pattern of the cathode matches the shape of the bridges of the flexible substrate, and the bridge pattern 164 is not easily broken during stretching.

In some embodiments of the present invention, the island pattern 162 has a stiffness greater than that of the bridge pattern 164. For example, the bridge pattern 164 and the island pattern 162 may be formed using different materials, and the material of the bridge pattern 164 has a stiffness smaller than that of the material of the island pattern 162. In this way, the island patterns 162 may form a flow module with the islands of the flexible substrate, and when the display panel is stretched or bent, the bridge patterns 164 between adjacent island patterns 162 may ensure that the island patterns 162 are more stably maintained on the islands of the flexible substrate by changing the shape and length thereof, preventing the island patterns from being separated from the film layer of the OLED.

In other embodiments, the thickness of the island pattern 162 is greater than the thickness of the bridge pattern 164. In this way, on the one hand, the rigidity of the bridge pattern 164 may be changed, increasing the flexibility of the bridge pattern 164, and reducing the stress generated when the flexible substrate is deformed. On the other hand, the breaking of the cathode during the stretching of the display panel can be prevented by increasing the length and shape of the bridge pattern 164.

In still other embodiments, the bridge pattern 164 has at least one convex portion and/or at least one concave portion in a direction perpendicular to the flexible display panel 10. Specifically, the convex and concave portions may be protrusions or grooves formed on the bridge pattern 164, or may be convex or concave portions formed by bending the bridge pattern 164 in a direction perpendicular to the flexible substrate. In one embodiment, the recess is a trench 169 formed between two adjacent island patterns 162.

In this way, the flexibility of the bridge pattern 164 may be changed, the stress generated during the stretching process may be released, and the rupture or damage of the cathode film layer may be prevented, thereby improving the stress and ductility of the cathode film layer.

It is understood that the cross-sectional shape of the groove 169 may be rectangular, V-shaped, inverted trapezoid, inverted cone, or the like, and is not limited thereto.

In order to better understand the advantages of the present invention, some embodiments will be described in detail below:

referring to fig. 3, the cathode includes a first cathode layer 166 and a second cathode layer 168, the first cathode layer 166 is formed on the corresponding pixel island region 12; a second cathode layer 168 is formed on the first cathode layer 166; a second cathode layer 168 is formed on the pixel island region 12 to constitute the island pattern 162; the second cathode layer 168 is also formed on the flexible region 14 to constitute a bridge pattern 164 connecting the island patterns 162 adjacent to each other.

For example, first, a first cathode layer 166 covering the pixel definition layer may be patterned by an evaporation or printing process, and the first cathode layer 166 corresponds to the pixel island region 12. It is to be understood that patterning the first cathode layer 166 may be exposing through a mask and then developing the first cathode layer 166 so that the first cathode layer 166 corresponds to the pixel island regions 12. Alternatively, the first cathode layer 166 may be formed on the entire surface of the flexible substrate, and then the portion to be removed is etched by an etching process, i.e., the portion corresponding to the flexible region 14 is etched away. It is understood that the patterning process may also take other forms, including but not limited to the two forms exemplified above.

Then, when the fabrication of the first cathode layer 166 is completed, a second cathode layer 168 may be formed on the first cathode layer 166 through an evaporation or printing process, the second cathode layer 168 being formed on the pixel island regions 12 to constitute the island patterns 162 and also being formed on the flexible regions 14 to constitute the bridge patterns 164 connecting the island patterns 162 adjacent to each other.

In this way, the thickness of the bridge pattern 164 is made smaller than that of the island pattern 162, and the trenches 169 located between adjacent island patterns 162 are formed, thereby changing the flexibility of the bridge pattern 164, releasing stress generated during the stretching process, preventing the cathode film layer from being broken or damaged, and thus improving the stress and ductility of the cathode film layer.

Further, the first cathode layer 166 is the same material as the second cathode layer 168. Specifically, the first and second cathode layers 166 and 168 are magnesium-silver alloys, for example, metal magnesium and metal silver are co-evaporated in an atomic ratio to form an alloy. Therefore, the alloy cathode is formed by adopting the metal with the low power function and the metal with the high power function and relatively stable chemical property, on one hand, electrons in the cathode can be injected into the electron injection layer relatively easily, the conductivity of the cathode is improved, on the other hand, the alloy film layer has better stress and ductility, and the cathode film layer can not be broken or damaged in the stretching or bending process of the display panel.

Of course, in other embodiments, the materials of the first cathode layer 166 and the second cathode layer 168 may be different, and are not limited herein.

It is particularly emphasized that when the display panel is stretched in at least one direction, for example, in a first direction and/or a second direction perpendicular to the first direction, stress is concentrated on the connection portion at the side of the flexible region 14 where the second cathode layer 168 is connected to the first cathode layer 166. Since the second cathode layer 168 is formed on the first cathode layer 166 so as to cover the entire surface thereof, and a part of the second cathode layer 168 covers the side surface of the first cathode layer 166, it has a slope-shaped curved surface, and thus, defects such as tearing of the film layer due to concentrated stress can be prevented.

Meanwhile, the second cathode layer 168 located in the flexible region 14 is stretched to transmit a part of the stress to the entire second cathode layer 168, thereby releasing the stress. And the reliability of the electrical connection can be ensured even if a part of the second cathode layer 168 is film-separated from the first cathode layer 166.

Based on the flexible display panel 10, the embodiment of the invention further provides a display device, which can be applied to any device that can be stretched or bent, for example, electronic devices such as wearable devices, vehicle-mounted devices, mobile phone terminals, tablet computers, display panels, and the like.

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

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

Claims

1. A flexible display panel having a plurality of pixel island regions spaced apart from each other, and a flexible region disposed between adjacent pixel island regions;

the flexible display panel is characterized by further comprising a cathode, wherein the cathode comprises island patterns formed in the corresponding pixel island regions, and a plurality of bridge patterns which are arranged in the flexible regions and connect the adjacent island patterns with each other;

the island pattern has a rigidity greater than that of the bridge pattern; the area of the bridge pattern is smaller than that of the island pattern, and the thickness of the island pattern is greater than that of the bridge pattern; in the direction perpendicular to the flexible display panel, the bridging pattern is provided with at least one convex part and/or at least one concave part;

the cathode comprises a first cathode layer and a second cathode layer;

the first cathode layer is formed in the corresponding pixel island region;

2. The flexible display panel of claim 1, wherein one of the island patterns corresponds to one of the pixel island regions.

3. The flexible display panel according to claim 1, wherein the convex portion and the concave portion are convex or concave portions formed by bending the bridge pattern in a direction perpendicular to the flexible display panel.

4. The flexible display panel according to claim 1, wherein the recess is a groove formed between two adjacent island patterns.

5. The flexible display panel of any of claims 1-4, wherein the first cathode layer and the second cathode layer are formed by an evaporation or printing process.

6. The flexible display panel of claim 5, wherein the first cathode layer and the second cathode layer are the same material.

7. The flexible display panel of claim 6, wherein the first cathode layer and the second cathode layer are of magnesium silver alloy.

8. The flexible display panel of claim 1, wherein the bridge pattern partially covers the flexible region.

9. The flexible display panel of claim 1, wherein the bridge pattern entirely covers the flexible region.

10. A display device comprising the flexible display panel according to any one of claims 1 to 9.