CN110429196B

CN110429196B - Display device, preparation method of display device and display device

Info

Publication number: CN110429196B
Application number: CN201811086927.6A
Authority: CN
Inventors: 陈颖; 唐卫东
Original assignee: Guangdong Juhua Printing Display Technology Co Ltd
Current assignee: Guangdong Juhua Printing Display Technology Co Ltd
Priority date: 2018-09-18
Filing date: 2018-09-18
Publication date: 2022-03-18
Anticipated expiration: 2038-09-18
Also published as: CN110429196A

Abstract

The invention relates to a display device, a preparation method of the display device and a display device. The display device includes: a TFT array substrate; the light-emitting layer is arranged on the TFT array substrate and comprises a plurality of pixel units; the scattering layer is arranged between the TFT array substrate and the light emitting layer and comprises light-blocking partition walls and a plurality of scattering units separated by the light-blocking partition walls, and the scattering units and the pixel units are arranged in a one-to-one correspondence mode. The display device is additionally provided with the scattering layers of the scattering units which are in one-to-one correspondence with the pixel units of the light emitting layer between the substrate and the light emitting layer, so that the light loss in a waveguide mode can be prevented, and the light emitting efficiency is improved; meanwhile, the light blocking partition wall can prevent crosstalk between adjacent pixel units due to scattered light, avoid the blurring phenomenon, and the scattering layer can also improve the image quality loss caused by uneven arrangement of factor pixels, so that the display effect of the high-resolution display is improved, and the requirement of high resolution can be met.

Description

Display device, preparation method of display device and display device

Technical Field

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

Background

As the demand for high resolution displays continues to increase, some techniques for achieving high resolution have come to work. Especially when there are certain size limitations in the equipment and manufacturing processes for color pixel generation, it is often necessary to explore how to break through the resolution limitations of the equipment and processes in order to achieve the smaller pixel size required for high resolution. For example, in the printing display technology, the ink drop size of the currently common inkjet printing apparatus cannot be infinitely reduced. Accordingly, the print pixels can only be printed accurately above a certain size. The current equipment process limit is often difficult to meet the requirements for higher resolution in the future, such as 4K × 2K and 8K × 4K of high resolution.

Disclosure of Invention

Accordingly, there is a need for a display device that can improve the display effect of a high-resolution display to meet the requirement of high resolution.

A display device, comprising:

a TFT array substrate;

the light-emitting layer is arranged on the TFT array substrate and comprises a plurality of pixel units;

the scattering layer is arranged between the TFT array substrate and the light emitting layer and comprises light-blocking partition walls and a plurality of scattering units separated by the light-blocking partition walls, and the scattering units and the pixel units are arranged in a one-to-one correspondence mode.

In one embodiment, each of the scattering units is surrounded by the light blocking partition wall.

In one embodiment, the display device further comprises a flat layer disposed between the scattering layer and the light emitting layer, and the light blocking partition wall is further embedded in the flat layer.

In one embodiment, the thickness of the flat layer is 0.1-20 μm, and the light blocking partition walls are at least embedded in 3/4 of the flat layer.

In one embodiment, the scattering unit comprises at least two materials with different refractive indexes, and the difference between the refractive indexes of the two materials is more than 15% of the refractive index of any one of the two materials.

In one embodiment, the refractive index of one of the two materials is 1.5 or less, and the refractive index of the other material is 1.9 or more.

In one embodiment, the light-blocking partition wall is prepared from photosensitive resin and black dye.

In one embodiment, the thickness of the scattering unit is 100 nm-100 μm.

Another object of the present invention is to provide a method for manufacturing a display device, including:

providing a TFT array substrate;

forming a scattering layer on the TFT array substrate, wherein the scattering layer comprises light-blocking partition walls and a plurality of scattering units partitioned by the light-blocking partition walls;

and forming a light emitting layer on the scattering layer, wherein the light emitting layer comprises a plurality of pixel units, and the pixel units and the scattering units are arranged in a one-to-one correspondence manner.

The invention further aims to provide a display device which comprises the display device or the display device prepared by the preparation method.

According to the display device, the scattering layer with the scattering units which are in one-to-one correspondence with the pixel units of the light emitting layer is additionally arranged between the substrate and the light emitting layer of the display device, so that light loss in a waveguide (waveguide) mode is prevented, and light emitting efficiency is improved; meanwhile, as the scattering units of the scattering layer are separated by the partition wall, crosstalk caused by scattered light among different pixel units can be prevented, and the blurring phenomenon is avoided; furthermore, due to the scattering effect of the scattering unit, the light emitting effect of the sub-pixels in the same pixel unit is closer to the light emitting effect of the whole pixel unit, so that the image quality loss caused by the uneven arrangement of the factor pixels is improved, the display effect of the high-resolution display is improved, and the requirement of high resolution can be met.

Drawings

FIG. 1 is a schematic diagram of a pixel arrangement of a light-emitting layer of a display device according to an embodiment of the present invention;

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

FIG. 3 is a schematic diagram of a scattering layer corresponding to the pixel arrangement of the light-emitting layer of the display device shown in FIG. 1 according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating the display effect of the light emission of the green sub-pixel on the oblique lines of the display device according to the embodiment of the invention.

Detailed Description

In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended 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.

The resolution of the OLED display screen is directly connected with the arrangement structure of the pixels, each pixel unit is provided with red, green and blue sub-pixels by reasonably arranging RGB sub-pixels, a better colorization effect is realized, and the sub-pixels with the same color are adjacent, so that evaporation of the pixels can be realized by using a mask with a larger opening or lower resolution, or the sub-pixels can be printed by using a printing process with lower resolution in the printing and displaying technology. As shown in fig. 1, is one of the solutions of this technique. The portion enclosed by the dotted line in fig. 1 is an RGB pixel unit, which includes red, green, and blue (RGB) sub-pixels. And the same colors are arranged together among the sub-pixels to form a larger same-color sub-pixel pit, thereby being beneficial to realizing corresponding resolution by evaporation or printing.

However, in research, the inventors found that the technology has corresponding problems. Taking the pixel arrangement scheme of fig. 1 as an example, when a green oblique line needs to be displayed, the actually displayed sub-pixels are often difficult to display uniformly due to the arrangement relationship. For example, when a 45-degree green oblique line passing through the pixel unit outlined by the dashed line is to be displayed in fig. 1, the sub-pixels G1, G2, and G3 in the figure are actually lit. Obviously, they do not actually lie in a straight line. If the same diagonal lines cross adjacent pixel units, the lighted pixels are completely different from the pixel arrangement in fig. 1, and they are not simply in a translation relationship. This results in that, when a high resolution image is actually displayed, the display using such a special pixel arrangement technique does not exhibit the detail as it would be with a conventional pixel arrangement.

Meanwhile, the scattering layer technology has been widely used in display manufacturing. The scattering layer is generally a film formed of a transparent host material, and is doped with metal particles or other particles having a refractive index significantly different from that of the host material, so that light can be scattered randomly when passing through the scattering layer. Its common functions include: improving the light uniformity of a liquid crystal white backplane, improving the viewing angle distribution of the light exiting in some displays, reducing total reflection at device interfaces to improve light output, and the like. However, in a display of RGB pixels, the application of a scattering layer suffers from a serious problem: scattering can cause light from a sub-pixel to spread even further into neighboring pixels, causing image blur. This makes it difficult to apply the scattering layer technology directly to a color display device of self-emissive RGB pixels. Thus, especially in high resolution applications, it becomes a challenge how to use the advantages of the scattering layer to avoid the adverse effects.

Therefore, the invention provides a display device capable of improving the high-resolution display effect by combining the high-resolution pixel arrangement design and the scattering layer in the bottom emission display based on the characteristics of the high-resolution pixel arrangement design and the scattering layer.

Referring to fig. 2 to 3, the display device 10 according to an embodiment of the invention may include a TFT array substrate 110, and a first planarization layer 120, a scattering layer 130, a second planarization layer 140, and a light emitting layer 150 sequentially disposed on the TFT array substrate 110.

In one embodiment, the TFT array substrate 110 is a transparent substrate with a TFT driver array.

In one embodiment, the first planarization layer 120 is disposed on the TFT array substrate 110 for planarizing the TFT array substrate to form a flat and planar upper surface.

Further, the first planarization layer 120 is a transparent planarization layer.

The scattering layer 130, disposed on the first planarization layer 120, includes light blocking partition walls 131 and a plurality of scattering units 132 separated by the light blocking partition walls 131.

In one embodiment, light blocking partition walls 131 are disposed around one scattering unit 132.

In one embodiment, the light blocking partition wall 131 is disposed around each of the scattering units 132, that is, each of the scattering units 132 is surrounded by the light blocking partition wall 131. Specifically, the light blocking partition walls 131 are formed in a grid shape by criss-cross sub-partition walls, and the scattering units are located in the grid-shaped grid region.

The second planarization layer 140 is disposed on the scattering layer 130, and the light blocking isolation wall 131 is embedded in the second planarization layer 140. That is, the light blocking partition walls 131 of the scattering layer 130 protrude from the upper edge of the TFT array substrate 110 away from the scattering unit 132 away from the upper surface of the TFT array substrate 110.

The light emitting layer 150 is disposed on the second planarization layer 140 and includes a plurality of pixel units (not shown in fig. 2), and the pixel units and the scattering units are disposed in a one-to-one correspondence.

Referring to fig. 3, a schematic diagram of a scattering layer corresponding to the pixel arrangement design of the light emitting layer of the display device of fig. 1 according to an embodiment is shown, where the scattering units are disposed in one-to-one correspondence with the positions of the pixel units.

It should be noted that, the scattering units are disposed in one-to-one correspondence with the positions of the pixel units, which means that the position of each scattering unit in the plurality of scattering units corresponds to the position of one pixel unit, and the display device includes a plurality of pairs of scattering units and pixel units corresponding to each other.

In an embodiment, referring to the pixel arrangement of the light emitting layer in fig. 1, a pixel unit is enclosed by a dashed line frame, each pixel unit includes three sub-pixels of red (R), green (G) and blue (B), and the RGB sub-pixels are arranged in a delta shape.

Specifically, with continued reference to fig. 1, the positions of the blue sub-pixel, the red sub-pixel and the green sub-pixel in the light-emitting layer do not overlap with each other, the number of the red sub-pixels or the green sub-pixels is twice the number of the blue sub-pixels, and the area of the single blue sub-pixel is about the sum of the areas of the single red sub-pixel and the single green sub-pixel. The blue sub-pixels are arranged in rows, the red sub-pixels or the green sub-pixels are arranged in rows in a double-interval manner, that is, two red sub-pixels, two green sub-pixels, two red sub-pixels and two green sub-pixels are arranged in the same row, and the positions of the red sub-pixels and the green sub-pixels can be exchanged integrally, as shown in fig. 1, two rows of blue sub-pixels, two rows of red sub-pixels arranged at intervals and two rows of green sub-pixels are arranged. Therefore, the sub-pixels with the same color are arranged together to form a larger same-color pixel pit, which is beneficial to evaporation or printing, and can increase the area of the blue sub-pixel in each pixel unit, improve the resolution of the display and correspondingly increase the service life of the blue sub-pixel.

In one embodiment, referring to fig. 2, the light emitting layer 150 includes a pixel bank 151 and a plurality of pixel pits 153 separated by the pixel bank 151, the plurality of pixel pits 153 are arranged in rows, and the pixel pits of two adjacent rows are arranged in a staggered manner (not shown), at least two electrodes 155 are disposed in each pixel pit, the electrodes 155 are connected to the TFT driving array on the substrate 110, so that at least two sub-pixels of the same color are disposed in each pixel pit 153, each electrode 155 corresponds to one sub-pixel, the sub-pixels are red sub-pixels, green sub-pixels or blue sub-pixels, and the adjacent red sub-pixels, green sub-pixels or blue sub-pixels form a pixel unit.

It will be appreciated that during printing of the emissive layer, the ink falls into pixel pits separated by pixel banks (banks), and the area actually emitting light is defined by the electrical plates within the pixel pits. Thus, in a high resolution pixel arrangement design, multiple electrodes can be accommodated within a pixel well, as shown in FIG. 2, and to illustrate this, two electrodes are separated within a pixel well, so that two separate, identically colored sub-pixels can be formed. The design of the light-emitting layer 150 is performed by using the pixel arrangement of fig. 1, when a red pixel or a green pixel is deposited in a pixel pit, four electrodes are separated in the pixel pit, so as to form 4 independent red sub-pixels or 4 independent green sub-pixels; when a blue pixel is deposited in the pixel pit, two electrodes are separated in the pixel pit, thereby forming 2 independent blue sub-pixels. The adjacent red sub-pixel, green sub-pixel and blue sub-pixel form a pixel unit.

It should be noted that there are many pixel arrangement modes of the high resolution display device, and fig. 1 is only one mode of the pixel arrangement of the high resolution display device of the present invention, and the patterning design of the scattering layer can be performed for different pixel arrangement modes, so as to satisfy the one-to-one corresponding arrangement of the positions of the scattering units and the pixel units. It is understood that the scattering units are disposed in one-to-one correspondence with the positions of the pixel units, and may or may not completely overlap in the top view orientation.

In one embodiment, the surface area of the scattering unit which is away from the TFT array substrate in one-to-one correspondence is equal to the surface area of the pixel unit which is away from the TFT array substrate. Thus, as shown in fig. 3, the scattering units and the pixel units are in one-to-one correspondence and completely overlap in the top view. As can be appreciated, the first and second,

in other embodiments, the surface area of the scattering unit facing away from the TFT array substrate and the surface area of the pixel unit facing away from the TFT array substrate may not be exactly the same.

In one embodiment, the thickness of the second planarization layer 140 is 0.1 μm to 20 μm.

In one embodiment, the light blocking partition walls 131 are embedded in at least 3/4 of the second planarization layer. Therefore, the light emitted by the device scattered in any direction in the scattering unit can be effectively prevented from entering the adjacent RGB pixel unit.

Further, the upper edge of the light blocking partition wall 131 is as close as possible to the surface of the second planarization layer 140 on the side away from the TFT array substrate.

In one embodiment, the scattering unit 132 includes at least two materials with different refractive indexes, and the difference between the refractive indexes of the two materials is greater than 15% of the refractive index of any one of the two materials.

It is understood that the scattering elements of the scattering layer can be made of materials with different refractive indexes, and the refractive indexes of the materials are obviously different, so that the absolute value of the difference between the refractive indexes of at least one pair of materials A, B in the mixed material is more than 15% of the refractive index of any one of the materials A or B.

In one embodiment, in the scattering unit, the weight percentage of the material A is 0.5-99.5%, and the weight percentage of the material B is 0.5-99.5%.

In one embodiment, the refractive index of material a is 1.5 or less and the refractive index of material B is 1.9 or more. Specifically, the material a may be silicone resin with a refractive index of 1.5 or less, and the material B may be metal oxide nano-or micro-particles with a refractive index of 1.9 or more, such as nano-or micro-titanium dioxide, zinc oxide, and the like.

In one embodiment, the light blocking partition wall 131 of the scattering layer 130 is a black light blocking partition wall, which is prepared from a mixture including a photosensitive resin and a black dye. Specifically, the black dye may be, but is not limited to, carbon black.

In one embodiment, the thickness of the scattering unit is 100 nm-100 μm.

It should be noted that the above structure must leave a via structure for the wiring of the electrodes. Preferably, the scattering layer, the first flat layer and the second flat layer comprise photosensitive resin in preparation raw materials, so that a via hole is reserved by adopting a photoetching method after each layer of working procedure, and the via hole can also be manufactured by matching the photoetching method with an ion beam etching process after all the layers are prepared.

Another embodiment of the present invention provides a method for manufacturing the above display device, including the steps of:

and S1, providing the TFT array substrate 110.

S2, a first planarization layer 120 is formed on the TFT array substrate 110.

S3, forming a scattering layer 130 on the first planarization layer 120, the scattering layer including light blocking partition walls 131 and a plurality of scattering units 132 separated by the light blocking partition walls 131.

In an embodiment, the light blocking partition wall 131 is formed on the first planarization layer 120, so as to define a plurality of scattering areas on the first planarization layer 120, and the scattering units 132 are deposited in the plurality of scattering areas, respectively, to obtain the scattering layer 130.

In an embodiment, referring to fig. 3, the scattering layer is patterned by using a conventional photolithography process and a black matrix process to form the black light-blocking partition wall 132, i.e., a black matrix. And coating scattering liquid containing materials with different refractive indexes in the prepared black matrix by solution methods such as printing, blade coating or spin coating, drying, and curing to form a film to obtain the scattering unit. Therefore, the scattering particles can be uniformly distributed in the silicone resin, and the scattering property is improved.

In other embodiments, a scattering unit material may be deposited on the first planarization layer 120, and then a conventional hole-forming process is used to remove the portion of the scattering unit where the light-blocking partition 132 is desired to be formed, and form a light-blocking partition in the region.

In one embodiment, the scattering liquid comprises at least two materials with different refractive indices, and the difference between the refractive indices of the two materials is greater than 15% of the refractive index of either one of the two materials.

Furthermore, the refractive index of one material is less than or equal to 1.5, and the refractive index of the other material is greater than or equal to 1.9. Specifically, one material may be silicone resin having a refractive index of 1.5 or less, and the other material may be metal oxide nano-or micro-particles having a refractive index of 1.9 or more, such as nano-or micro-sized titanium dioxide, zinc oxide, and the like.

In one embodiment, the scattering liquid further comprises an organic solvent. Wherein, the organic solvent can be but is not limited to isopropanol and ethanol.

In one embodiment, the weight percentage of the organic solvent in the scattering liquid is 40% to 90%.

In one embodiment, in order to improve the scattering property of the scattering layer and prevent the scattering particles from aggregating, the scattering liquid further comprises 2 wt% to 30 wt% of a dispersing agent. Specific examples of the dispersant include acetylacetone.

S4, forming a second planarization layer 140 on the scattering layer. The flat layer can be prepared by adopting conventional processes such as blade coating, spin coating and the like. The material of the second flat layer may be an insulating resin, a metal oxide insulating layer.

S5, preparing a light-emitting layer 150 on the second planarization layer 140, wherein the light-emitting layer 150 includes a plurality of pixel units, and each pixel unit includes three sub-pixels of red, green and blue; the positions of the pixel units and the scattering units 132 are arranged in one-to-one correspondence.

Specifically, a patterned pixel bank 151 is formed on the second planarization layer 140, the pixel bank 151 surrounds a plurality of pixel pits 153 on the scattering layer, the pixel pits 153 are arranged in rows, and the pixel pits in two adjacent rows are arranged in a staggered manner; then at least two electrodes 155 are formed in each pixel pit, and the electrodes 155 are connected with the TFT drive array on the substrate 110; referring to the pixel arrangement shown in fig. 1, the light-emitting layer ink is printed in the pixel pits, and is dried to form a film, so that at least two sub-pixels with the same color are formed in each pixel pit 153, each electrode 155 corresponds to one sub-pixel, the sub-pixels are red sub-pixels, green sub-pixels or blue sub-pixels, the adjacent red sub-pixels, green sub-pixels and blue sub-pixels form a pixel unit, and the positions of the pixel units and the scattering units 132 are arranged in a one-to-one correspondence manner.

It should be noted that the above structure must leave a via structure for the wiring of the electrodes. Preferably, the scattering layer and the planarization layer are made of photosensitive resin, so that a via hole is formed by photolithography after each layer of the process, or the via hole is formed by photolithography and ion beam etching after the planarization layer is completely made.

Another embodiment of the present invention provides a display device including the above display device or the display device manufactured by the above method.

In the display device of the above embodiment of the present invention, the scattering layer having the scattering units corresponding to the pixel units of the light emitting layer one to one is additionally arranged in the light emitting direction of the display device, so that light loss in a waveguide (waveguide) mode is prevented, and light emitting efficiency is improved; meanwhile, as the scattering units of the scattering layer are separated by the light-blocking partition walls, crosstalk between different pixel units due to scattered light can be prevented, and the blurring phenomenon is avoided; further, due to the scattering effect of the scattering unit, the light emitting effect of the sub-pixels in the same pixel unit is closer to the light emitting effect of the whole pixel unit, so that the image quality loss caused by the uneven arrangement of the factor pixels is improved, as shown in fig. 4, the light emitting display effect of the green sub-pixels positioned on the non-straight line in the display device according to the embodiment of the invention is realized, and through the scattering effect of the scattering unit, the light emitted by the green sub-pixels is repeatedly scattered in the corresponding scattering unit in the scattering layer until being emitted from the front side, so that the visual effect of the light emitted by the whole RGB pixel unit is formed, and the green display effect positioned on the oblique line is shown, so that the visual discontinuity feeling caused by the too far distance of the factor pixels can be effectively avoided, the image quality is effectively improved, the display effect of the high-resolution display is improved, and the requirement of high resolution is met.

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 display device, comprising:

a TFT array substrate;

the light-emitting layer is arranged on the TFT array substrate and comprises a plurality of pixel units; the pixel unit comprises a red sub-pixel, a green sub-pixel and a blue sub-pixel which are adjacently arranged;

2. The display device according to claim 1, wherein each of the scattering units is surrounded by the light blocking partition wall.

3. The display device according to claim 1, further comprising a planarization layer disposed between the scattering layer and the light emitting layer, wherein the light blocking partition wall is further embedded in the planarization layer.

4. The display device according to claim 3, wherein the thickness of the planarization layer is 0.1 μm to 20 μm, and the light blocking partition wall is embedded in at least 3/4 of the planarization layer.

5. The display device according to claim 1, wherein the scattering unit comprises at least two materials having different refractive indices, the difference between the refractive indices of the two materials being greater than 15% of the refractive index of either material.

6. The display device according to claim 5, wherein one of the two materials has a refractive index of 1.5 or less, and wherein the other material has a refractive index of 1.9 or more.

7. The display device according to claim 1, wherein the material for forming the partition wall comprises a photosensitive resin and a black dye.

8. The display device according to any one of claims 1 to 7, wherein the thickness of the scattering unit is 100nm to 100 μm.

9. A method of fabricating a display device, comprising:

providing a TFT array substrate;

forming a light emitting layer on the scattering layer, wherein the light emitting layer comprises a plurality of pixel units, and the pixel units and the scattering units are arranged in a one-to-one correspondence manner;

the pixel unit comprises a red sub-pixel, a green sub-pixel and a blue sub-pixel which are adjacently arranged.

10. A display device comprising the display device according to any one of claims 1 to 8 or a display device manufactured by the manufacturing method according to claim 9.