阅读说明：本技术 柔性显示面板及显示装置 (Flexible display panel and display device ) 是由 陈亚文 史文 于 2019-08-02 设计创作，主要内容包括：本发明涉及一种柔性显示面板及显示装置,包括基板、子像素电极、像素限定层、发光单元及顶电极。子像素电极为多个且设于基板上；像素限定层设于多个子像素电极上且设有多个像素坑；发光单元,发光单元为多个,多个发光单元形成间隔设置的多排发光单元,发光单元一一对应设置于像素限定层的像素坑内且覆盖子像素电极的有效区域；顶电极为多个,各顶电极为条状,且每个顶电极对应一排发光单元设置,顶电极的延伸方向与柔性显示面板的可弯折线的延伸方向相同。如此能够提高柔性显示面板的抗弯折性能,进而提高整个面板的显示效果。(The invention relates to a flexible display panel and a display device. The plurality of sub-pixel electrodes are arranged on the substrate; the pixel limiting layer is arranged on the plurality of sub-pixel electrodes and is provided with a plurality of pixel pits; the light-emitting units are arranged in the pixel pits of the pixel limiting layer in a one-to-one correspondence mode and cover the effective areas of the sub-pixel electrodes; the top electrodes are multiple and strip-shaped, each top electrode is arranged corresponding to one row of light emitting units, and the extending direction of the top electrodes is the same as the extending direction of the bendable line of the flexible display panel. So can improve flexible display panel's anti bending performance, and then improve the display effect of whole panel.)

1. A flexible display panel, comprising:

a substrate;

a plurality of sub-pixel electrodes arranged on the substrate, the sub-pixel electrodes having an effective area;

a pixel defining layer provided on the plurality of sub-pixel electrodes and provided with a plurality of pixel pits, an effective area of each sub-pixel electrode being exposed to each pixel pit;

the light-emitting units are arranged in the pixel pits of the pixel limiting layer in a one-to-one correspondence mode and cover the effective areas of the sub-pixel electrodes; and

the flexible display panel comprises a plurality of top electrodes, each top electrode is strip-shaped, each top electrode is correspondingly arranged on one row of light-emitting units, and the extending direction of the top electrodes is the same as the extending direction of a bendable line of the flexible display panel.

2. The flexible display panel of claim 1, further comprising an auxiliary electrode between the top electrode and the substrate and connected to the top electrode.

3. The flexible display panel of claim 2, wherein the auxiliary electrode is disposed in the same layer as the subpixel electrode.

4. The flexible display panel of claim 2, wherein the auxiliary electrode and the sub-pixel electrode are made of the same material.

5. The flexible display panel according to claim 2, wherein the auxiliary electrode is positioned between adjacent two of the light emitting cells in the same row of light emitting cells.

6. The flexible display panel according to claim 5, wherein the auxiliary electrode is provided between any adjacent light emitting cells in the same row of light emitting cells.

7. The flexible display panel of any of claims 1-6, wherein the top electrode is a transparent electrode.

8. The flexible display panel of claim 7, wherein the sub-pixel electrode is a reflective conductive film layer; the top electrode is a transparent conductive metal oxide layer or a transparent metal layer.

9. The flexible display panel according to any one of claims 1 to 6, further comprising inverted trapezoidal electrode isolation pillars disposed on the pixel defining layer and between two adjacent top electrodes, wherein an extending direction of the electrode isolation pillars is the same as an extending direction of the top electrodes.

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

Technical Field

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

Background

In the contemporary information society, the importance of displays as a visual information transmission medium is further strengthened, and displays are being developed toward the trend of lighter, thinner, lower power consumption, lower cost, and better image quality in order to dominate in the future.

Organic electroluminescent diodes (OLEDs) are known to be the next day in the huge industrial market of display and illumination following the current LEDs (light emitting diodes) and LCDs (liquid crystal displays) due to their advantages of self-luminescence, low power consumption, fast response speed, wide viewing angle, high resolution, wide temperature range, high brightness, high contrast, good vibration resistance, ultra-thin profile, etc.

The flexible display is advantageous not only in a small-sized portable machine but also in a large-sized television because of its advantages of being light, thin, and flexible. The flexible OLED has great advantages and competitiveness in the fields of flexible display, illumination and the like. However, the top electrode of the current OLED is generally a surface electrode, and when the OLED is used for a flexible panel, the top electrode is easily broken during the bending process, which results in poor display.

Disclosure of Invention

Accordingly, it is desirable to provide a flexible display panel and a display device capable of improving bending resistance.

A flexible display panel comprising:

a substrate;

a plurality of sub-pixel electrodes arranged on the substrate, the sub-pixel electrodes having an effective area;

a pixel defining layer provided on the plurality of sub-pixel electrodes and provided with a plurality of pixel pits, an effective area of each sub-pixel electrode being exposed to each pixel pit;

the light-emitting units are arranged in the pixel pits of the pixel limiting layer in a one-to-one correspondence mode and cover the effective areas of the sub-pixel electrodes; and

the flexible display panel comprises a plurality of top electrodes, each top electrode is strip-shaped, each top electrode corresponds to one row of light emitting units, and the extending direction of the top electrodes is the same as the extending direction of a bendable line of the flexible display panel.

In one embodiment, the flexible display panel further includes an auxiliary electrode between the top electrode and the substrate and connected to the top electrode.

In one embodiment, the auxiliary electrode and the sub-pixel electrode are disposed in the same layer.

In one embodiment, the auxiliary electrode and the sub-pixel electrode are made of the same material.

In one embodiment, the auxiliary electrode is located between two adjacent light emitting cells in the same row of light emitting cells.

In one embodiment, the auxiliary electrode is disposed between any adjacent light emitting cells in the same row of light emitting cells.

In one embodiment, the top electrode is a transparent electrode.

In one embodiment, the sub-pixel electrode is a reflective conductive film layer; the top electrode is a transparent conductive metal oxide layer or a transparent metal layer.

In one embodiment, the liquid crystal display further includes an inverted trapezoid electrode isolation column, the electrode isolation column is disposed on the pixel defining layer and located between the two adjacent top electrodes, and an extending direction of the electrode isolation column is the same as an extending direction of the top electrodes.

A display device comprising a flexible display panel as claimed in any one of the preceding claims.

According to the invention, the top electrodes are arranged into strips along the extending direction of the bendable line of the flexible display panel, the interval is arranged between every two adjacent top electrodes to form the stress release area, and the stress of the flexible display panel in the bending process along the bendable line is released in the stress release area, so that the problem of poor display caused by the fact that the top electrodes are broken in the bending process of the flexible display panel along the bendable line is avoided, the bending resistance of the flexible display panel can be improved, and the display effect of the whole panel is further improved.

Drawings

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

fig. 2 is a schematic structural diagram of a cross section of the flexible display panel shown in fig. 1 along i;

FIG. 3 is a schematic view of the structure of FIG. 2 without the light-emitting unit and the top electrode;

FIG. 4 is a schematic structural diagram of a cross section of the flexible display panel shown in FIG. 1 along II;

FIG. 5 is a schematic view of the structure of FIG. 4 without the light-emitting unit and the top electrode;

fig. 6 to 9 are schematic views of the manufacturing process structure of the flexible display panel shown in fig. 1.

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.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

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.

Referring to fig. 1, an embodiment of the invention provides a flexible display panel 10. The structure of the flexible display panel 10 will be described in detail below with reference to a method for manufacturing the flexible display panel 10.

Referring to fig. 1 to 3, the display panel may include a substrate 11, a sub-pixel electrode 12, a pixel defining layer 13, a light emitting unit 14, and a top electrode 15.

In one embodiment, the substrate 11 may include a flexible substrate and a Thin-film transistor (TFT) array disposed on the flexible substrate for driving a light emitting device to display an image. The flexible substrate may be formed of a suitable material among plastic materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or Polyimide (PI).

Of course, the substrate 11 may include a planarization layer, a passivation layer, and other film layers besides the thin film transistor, and is not limited herein.

The number of the sub-pixel electrodes 12 is plural. And a plurality of sub-pixel electrodes 12 are disposed on the substrate, the sub-pixel electrodes 12 having an effective area. It is understood that the effective area of the sub-pixel electrode 12 refers to a portion of the sub-pixel 12 not covered by the pixel defining layer 13, i.e., an area exposed to the pixel defining layer 13, which is in contact with the light emitting unit 14.

It will be appreciated that the plurality of sub-pixel electrodes 12 are arranged in a plurality of spaced rows, each row containing a plurality of sub-pixel electrodes 12. It will be appreciated that the sub-pixel electrodes 12 are conductive film layers which are connected to the drive circuitry in the underlying TFT array by connecting vias.

The pixel defining layer 13 is disposed on the plurality of sub-pixel electrodes 12 and is provided with a plurality of pixel pits such that an effective area of each sub-pixel electrode 12 is exposed to each pixel pit.

The light emitting unit 14 is plural. The plurality of light emitting cells 14 form a plurality of rows of light emitting cells arranged at intervals. The light emitting units 14 are disposed in the pixel pits of the pixel defining layer 13 in a one-to-one correspondence and cover the effective areas of the sub-pixel electrodes 12.

It is understood that each row of light emitting units includes at least two light emitting units 14.

It can be understood that the light emitting units 14 in each row of light emitting units are arranged in sequence along the row direction; accordingly, the plurality of rows of light emitting cells are sequentially arranged in the column direction. It is understood that, in some examples, the light emitting units 14 in each row of light emitting units are arranged in sequence in the column direction; accordingly, a plurality of rows of the light emitting cells are sequentially arranged in a row direction.

Further, in some examples, the light emitting cells are distributed in a matrix in a row direction and a column direction.

The top electrode 15 is plural. Each top electrode 15 is in a strip shape, each top electrode 15 is disposed corresponding to a row of light emitting units, an extending direction 101 of the top electrode 15 is the same as an extending direction of a bendable line of the flexible display panel 10, and a space is formed between two adjacent top electrodes 15 to form a stress relief region.

It can be understood that the bendable line of the flexible display panel 10 is perpendicular to the bending direction of the flexible display panel 10 shown in fig. 4. The bending direction of the flexible display panel 10 shown in fig. 4 is a direction in which two portions of the flexible display panel 10 bent from each other move relative to each other.

According to the invention, the top electrodes 15 are arranged into a strip shape along the extending direction of the bendable line of the flexible display panel 10, the interval is arranged between two adjacent top electrodes 15 to form the stress release region, and the stress of the flexible display panel 10 in the bending process along the bendable line is released in the stress release region, so that the problem of poor display caused by the fact that the top electrodes 15 are broken in the bending process of the flexible display panel 10 along the bendable line is avoided, the bending resistance of the flexible display panel 10 can be improved, and the display effect of the whole panel is further improved.

In addition, the strip-shaped top electrode 15 can simplify the circuit distribution and the process compared to the top electrodes independently disposed corresponding to the light emitting units 14.

In one embodiment, the flexible display panel 10 is a top emission type panel, which has a high aperture ratio. Further, the sub-pixel electrode 12 is a reflective conductive film layer, and the top electrode 15 is a transparent electrode, so as to improve the light extraction efficiency.

Further, the sub-pixel electrode 12 is made of Al, Ag or ITO/Ag/ITO, wherein ITO/Ag/ITO is Ag-doped ITO, i.e., a laminate of ITO, Ag and ITO. Further, the sub-pixel electrode 12 has a thickness of 50nm to 250 nm. Further, the material of the top electrode 15 includes, but is not limited to, a transparent conductive metal oxide and a thin metal layer, wherein the transparent conductive metal oxide may include Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), Indium Gallium Oxide (IGO), Aluminum Zinc Oxide (AZO), or the like. The material of the thin layer metal can be Al, Ag, Mg or an alloy of at least two of the three, such as a magnesium-silver alloy. That is, in some embodiments, the top electrode 15 is a transparent conductive metal oxide layer or a transparent metal layer.

Generally, when the top electrode 15 is a transparent conductive metal oxide layer, the transparent conductive metal oxide layer is not strong in bendability, and is easily broken in a bending process when used for a flexible panel, so that a problem of poor display is caused; however, since the top electrode 15 in the present invention is disposed in a strip-like structure along the extending direction of the bendable line of the flexible display panel 10, the problem of poor display caused by the top electrode 15 breaking during the bending process of the flexible display panel 10 along the bendable line is effectively avoided.

Referring to fig. 2, further, when the top electrode 15 is a transparent conductive metal oxide layer or a transparent metal layer, the sheet resistance of the top electrode 15 is larger, so that the auxiliary electrode 16 connected to the top electrode 15 can be added to improve the conductivity of the top electrode 15, reduce the voltage drop of the panel, and improve the uniformity of the display. In order to ensure the bending flexibility of the panel, the auxiliary electrode 16 is disposed below the top electrode 15 and corresponds to a position where the light emitting unit 14 is not disposed, where the lower is with respect to the substrate 11, that is, the auxiliary electrode 16 is located between the top electrode 15 and the substrate 11. The auxiliary electrode 16 is disposed at a position away from the light emitting unit 14, and does not affect the light emission of the light emitting unit 14. And because the stress of the flexible display panel 10 in the bending process is released in the stress release region, the problem of uneven panel light emission caused by connection failure between the auxiliary electrode 16 and the top electrode 15 in the bending process can be prevented.

In some embodiments, the auxiliary electrode 16 is disposed in the same layer as the sub-pixel electrode 12. That is, the auxiliary electrode 16 is provided on the substrate, and the pixel defining layer 13 is provided on the sub-pixel electrode 12 and the auxiliary electrode 16. Then, a pixel pit and an auxiliary electrode connection hole 161 are formed at positions of the pixel defining layer 13 corresponding to the sub-pixel electrode 12 and the auxiliary electrode 16, respectively, so that the top electrode 15 is formed in the pixel pit and in the auxiliary electrode connection hole 161 in synchronization. It is understood that the openings of the pixel pits and the auxiliary electrode connection holes 161 are both inverted trapezoidal openings, thus facilitating the formation of the continuous top electrode 15.

Further, the auxiliary electrode 16 and the sub-pixel electrode 12 are made of the same material. Further, the auxiliary electrode 16 and the sub-pixel electrode 12 may be formed in the same process step, and specifically, the auxiliary electrode 16 may be formed using the same mask in the step of forming the sub-pixel electrode 12.

Further, the auxiliary electrode 16 is positioned between adjacent two light emitting cells 14 in the same row of light emitting cells.

Further, the number of the auxiliary electrodes 16 may be plural. In one embodiment, an auxiliary electrode 16 is disposed between any two adjacent light emitting cells 14 in the same row of light emitting cells. It is understood that the auxiliary electrode 16 may be disposed between any adjacent two light emitting cells 14 in each row of light emitting cells. It is understood that in some embodiments, there may be a plurality of auxiliary electrodes 16 located between the adjacent two light emitting cells 14.

Referring to fig. 1, 4 and 5, in one embodiment, in order to form the top electrode 15 in a stripe shape, an inverted trapezoid-shaped electrode isolation pillar 17 may be formed on the pixel defining layer 13 before the step of forming the top electrode 15. Specifically, the electrode isolation pillars 17 are disposed between two adjacent rows of light emitting cells, and the extending direction of the electrode isolation pillars 17 is the same as that of each row of light emitting cells, so that the extending direction 101 of the top electrode 15 is formed to be the same as that of the electrode isolation pillars 17. Thus, the electrode isolation region where the electrode isolation pillar 17 is located is the stress relief region. Specifically, the step of forming the electrode isolation pillars 17 precedes the step of forming the light emitting cells 14.

Referring to fig. 6 to 9, in an embodiment, a method for manufacturing the flexible display panel 10 includes the following steps: the sub-pixel electrodes 12 are first formed on the substrate 11 as shown in fig. 6. Then, a pixel defining layer 13 is formed on the sub-pixel electrode 12, and then, a pixel pit is pattern-formed on the pixel defining layer 13 by using a process such as photolithography, as shown in fig. 7. Then, an organic photoresist is coated on the pixel defining layer 13 and patterned by a process such as photolithography to form the above-described electrode isolation pillars 17, as shown in fig. 8. The light emitting cells 14 are then printed within the pixel pits as shown in fig. 9. Then, a top electrode 15 is formed on the substrate 11 including the light emitting unit 14 by a sputtering process or the like, as shown in fig. 4. Here, due to the barrier effect of the electrode barrier pillars, when the top electrode 15 is formed on the substrate 11 by a sputtering process or the like, the conductive material of the top electrode 15 can be blocked, and thus the top electrode 15 is formed in a linear or strip-like distribution. That is, the electrode isolation pillar 17 is provided on the pixel defining layer 13 and between two adjacent top electrodes 15.

It is understood that the material of the electrode isolation pillar 17 includes, but is not limited to, an organic photoresist. The electrode isolation columns 17 made of organic materials can improve the bending resistance of the flexible display panel 10, and further improve the display effect of the whole panel.

It can be understood that the conductive material of the top electrode 15 is deposited on the electrode isolation pillars 17 during the step of forming the top electrode 15, however, when the top electrode 15 is a transparent electrode, the conductive material does not affect the light extraction efficiency, so that the conductive material on the electrode isolation pillars 17 does not need to be stripped.

It is understood that the light-emitting unit 14 may include other functional layers such as a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer, in addition to the light-emitting layer. In some embodiments, the functional layers of the light-emitting unit 14 are formed using corresponding ink-jet printing. The solution processing is adopted to prepare the OLED and other display panels, and the method is an important direction for the development of future display technologies, particularly for preparing the display panels by a printing process due to the advantages of low cost, high productivity, easy realization of large size and the like. Therefore, the printing process is applied to the manufacturing process of the flexible display panel 10, and combines the advantages of the two processes, so that the flexible display panel is very attractive in future display.

Further, the wetting between the ink and the bottom end of the sidewall of the pixel pit (i.e., the bottom end of the ink and the pixel defining layer 13) is such that the ink can be better spread within the pixel pit, can be better contacted with the sidewall of the pixel pit, and forms a thin film of uniform thickness; and the ink is not wet between the top of the sidewall of the pixel pit (i.e. the top of the ink and the pixel defining layer 13), between the ink and the upper surface of the pixel defining layer 13 away from the substrate 11, so that a larger contact angle can be formed, thereby accommodating more ink and limiting the flow of the ink in the pixel pit, and preventing the overflow of the ink from causing color mixing.

In some embodiments, the ink is lyophilic, so the bottom end of the pixel defining layer 13 is set to be lyophilic and the top and upper surface of the pixel defining layer 13 are set to be lyophobic.

In some embodiments, the thickness of the pixel defining layer 13 is 800nm to 1500 nm.

An embodiment of the present invention further provides a display device, including the display panel 10.

In some embodiments, the display device may be a television, a tablet, a cell phone, or 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.