WO2015188595A1

WO2015188595A1 - Display panel and manufacturing method thereof, and display device

Info

Publication number: WO2015188595A1
Application number: PCT/CN2014/092361
Authority: WO
Inventors: 崔颖; 代青
Original assignee: 京东方科技集团股份有限公司
Priority date: 2014-06-12
Filing date: 2014-11-27
Publication date: 2015-12-17
Also published as: CN104051670A; CN104051670B

Abstract

A display panel, comprising a substrate (101), a display device (102), and a light converging layer (103) and a light absorption layer (104) located between the substrate (101) and the display device (102); the light converging layer (103) and the light absorption layer (104) are sequentially arranged in the external light incident direction; the light converging layer (103) is used to converge the external light; the light absorption layer (104) is located at the external light converging position, and used to absorb the converged external light. The present invention effectively reduces the reflection of the external light inside a device, and ensures that light emitted from inside the device is not blocked, that is, the brightness of the device is not reduced. Compared with the conventional method of pasting a polarizer, the present invention dramatically improves the brightness, and reduces the production cost, the thickness of the display panel and the risk of good product rate decreasing caused by pasting the polarizer.

Description

Display panel, manufacturing method thereof, and display device

Technical field

The present invention relates to the field of display technologies, and in particular, to a display panel, a manufacturing method thereof, and a display device.

Background technique

Since the substrate on the observation surface side of the display panel is usually a transparent glass substrate, external ambient light enters the inside of the display panel from the transparent substrate, and is reflected by the metal electrode or the like inside the display panel, resulting in a decrease in contrast of the display panel. Taking an organic light emitting device (OLED) display panel as an example, an organic light-emitting device is generally composed of an anode, a cathode, and an organic light-emitting functional layer sandwiched therebetween, and can be classified according to the light-emitting direction thereof. Bottom emission type and top emission type organic light emitting devices. For the bottom emission type organic electroluminescent device, since the top electrode is usually made of a highly reflective metal material, external light enters the inside of the display device from the transparent bottom electrode, and the top electrode is infiltrated due to the reflection effect of the top electrode. The external light inside the display device is reflected. Such external light reflected from the inside of the device causes a greatly reduced contrast in the display device, particularly in the case of black display, and causes the observation surface (reflection surface) of the metal electrode to be reflected in the surrounding image, thereby making The visibility of the display is reduced.

As a simple method for preventing such a deterioration in display quality due to reflection of a metal electrode, there is a method in which a polarizing layer used for an LCD is disposed on a transparent glass substrate, that is, a viewing surface (light emitting surface) of a module, such as a Japanese patent. JP-A-7-142170 discloses that a polarizing layer is disposed on the light-emitting surface side of the module, and the light that is incident from the outside of the module into the module can be shielded by the polarizing layer, reflected by the metal electrode on the back side, and emitted again from the assembly. That is, the external light that is incident into the module through the polarizing layer from the outside of the module is a linearly polarized light parallel to the polarizing direction of the polarizing layer, and the linear polarized light is reflected by the metal electrode, and its polarization direction is reversed by 90°. Then, since the polarization direction of the reflected light of the metal electrode is different from the polarization direction of the polarizing layer, it cannot pass through the polarizing layer and is blocked.

By providing the polarizing layer in this way, the reflected light on the light exiting surface is prevented from being emitted, and the decrease in contrast can be suppressed. However, since there is a polarizing layer on the light exit side of the module, light from the light emitting layer If it does not pass through the polarizing layer, it cannot be output to the outside. On the other hand, the polarizing layer can pass only the light parallel to the polarizing direction of the polarizing layer in the light emitted from the light emitting layer. Therefore, most of the emitted light cannot pass through the polarizing layer, thereby reducing the utilization efficiency of the light. In addition, the polarizing layer not only increases the manufacturing process of the display panel, but also increases the thickness of the display panel.

Summary of the invention

In order to solve the above technical problems, the present invention provides a display panel, a manufacturing method thereof, and a display device.

According to an aspect of the present invention, there is provided a display panel comprising a substrate, a display device, and a light concentrating layer and a light absorbing layer between the substrate and the display device, the light concentrating layer and the light absorbing layer incident along external light The directions are arranged in order, and the light collecting layer is used for collecting external light, and the light absorbing layer is located at a gathering place of the external light for absorbing the concentrated external light.

In an embodiment, the light converging layer comprises a plurality of microlenses distributed in an array.

In one embodiment, the microlens is in the shape of a hemisphere including a top surface and a bottom surface, the bottom surface being a spherical surface, the top surface being a circular plane, the top surface facing the light absorbing layer, the bottom surface facing the substrate.

In an embodiment, the spacing between the plurality of microlenses is greater than the diameter of a single microlens.

In an embodiment, the microlens is made of a transparent, non-absorbent material.

In one embodiment, the microlens is made of polyacrylic resin, acryl resin, methacrylic resin, urethane resin, polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, fiber resin, polystyrene. One of the materials of the resin is made of or mixed with a plurality of materials.

In an embodiment, the display panel further includes a flat layer, the microlens is embedded inside the flat layer, and the flat layer has a refractive index smaller than a refractive index of the microlens material.

In an embodiment, the light absorbing layer is located at a focus position of the microlens.

In an embodiment, the area of the light absorbing layer is smaller than the area of the microlens.

In one embodiment, the light absorbing layer is formed by mixing one or more of carbon black, black resin, and black titanium compound lacking one oxygen atom.

In an embodiment, the display panel further includes a light scattering layer on a side of the light absorbing layer facing the display device for scattering light emitted inside the display panel.

In an embodiment, the light scattering layer is made of a transparent material doped with scattering particles.

In an embodiment, the light scattering layer has the same area as the light absorbing layer.

According to a second aspect of the present invention, there is provided a display device comprising the display panel of any of the above embodiments.

According to a third aspect of the present invention, there is provided a method of fabricating a display panel, comprising: forming a substrate, a display device, and a light concentrating layer and a light absorbing layer between the substrate and the display device; wherein the light concentrating layer and the light The absorbing layer is sequentially arranged along the incident direction of the external light, and the light concentrating layer is used for concentrating the external light, and the light absorbing layer is located at the convergence of the external light for absorbing the concentrated external light.

In an embodiment, forming the light converging layer and the light absorbing layer between the substrate and the display device comprises:

Providing a substrate;

Forming a light converging layer on the substrate;

Forming a light absorbing layer at an external light convergence point above the light collecting layer;

Create a display device.

In an embodiment, forming a light collecting layer on the substrate comprises:

Forming a first planar layer on the substrate;

Forming a plurality of microlenses distributed in an array in the first planar layer;

A second planar layer is formed over the microlenses.

In one embodiment, the microlens employs a transparent, non-absorbent material and has a refractive index greater than a refractive index of the planar layer.

In an embodiment, the forming a light absorbing layer at the outer light gathering area above the light collecting layer comprises:

A light absorbing layer having an area smaller than that of the microlens is formed at a focus position of each of the microlenses.

In an embodiment, the method further includes:

A light scattering layer having an area equal to that of the light absorbing layer is formed on a side of the light absorbing layer facing the display device, and the light scattering layer is made of a transparent material doped with scattering particles.

The present invention forms a light converging layer formed of a plurality of microlenses between a substrate and a display device, and forms an absorption layer at a light converging portion of the microlens such that external light converges in the photo lens when passing through the microlens At the absorbing layer, absorbed by the absorbing layer to prevent or weaken external light The adverse effect of the reflection on the display; at the same time, the present invention also forms a scattering layer on the absorbing layer, and the internal light of the display device irradiated onto the absorbing layer is scattered by the scattering layer due to the existence of the scattering layer, without being absorbed by the absorbing layer The light absorbed by the scattering layer is scattered and then emitted to the outside of the device. In summary, the display panel provided by the present invention effectively reduces the reflection of external light inside the device, and ensures that the illumination inside the device is not blocked, that is, the brightness of the device is not attenuated, and the conventional method of attaching the polarizer In comparison, the brightness is significantly improved, and the thickness of the display panel is reduced, and the risk of yield drop due to the polarizer is reduced, and the cost is saved.

DRAWINGS

1 is a schematic structural view of a display panel in a first embodiment of the present invention;

2 is a schematic structural view of a display panel according to a second embodiment of the present invention;

3(a) to (c) are schematic diagrams showing optical paths of external light and internal light passing through a microlens, a light absorbing layer, and a light scattering layer in the present invention;

4a is a flow chart of a method for manufacturing a display panel according to an embodiment of the present invention;

4b illustrates an exemplary step of forming a light converging layer on a substrate in accordance with an embodiment of the present invention;

5(a) to (f) are flow charts showing the manufacturing process of the display panel in the embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the specific embodiments of the invention,

In the following detailed description, numerous specific details are set forth Obviously, however, one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in the drawings in the drawings.

According to the present general inventive concept, there is provided a display panel including a substrate, a display device, and a light concentrating layer and a light absorbing layer between the substrate and the display device, the light concentrating layer and the light absorbing layer being exposed to external light The incident direction is arranged in order, and the light collecting layer is used for collecting external light, and the light absorbing layer is located at the convergence of the external light for absorbing the concentrated external light.

FIG. 1 is a schematic structural view of a display panel according to a first embodiment of the present invention. As shown in FIG. 1, it includes a substrate 101, a display device 102, and a light collecting layer 103 and a light absorbing layer 104 between the substrate 101 and the display device 102, the light collecting layer 103 and the light absorbing layer 104 along the external light. The incident direction is arranged in order, and the light collecting layer 103 is used for collecting external light, and the light absorbing layer 104 is located at the convergence of the external light for absorbing the concentrated external light.

The display panel described in the present invention may be a liquid crystal display panel or an OLED display panel, wherein the display device is a liquid crystal display device or an OLED display device.

The external light mentioned in the present invention is light that enters the inside of the display panel from the outside of the display panel. Since the viewer side of the display panel is usually made of a transparent glass substrate, external light usually enters the inside of the display panel from the observer side. In addition, the internal light mentioned in the present invention has two meanings: First, if the display panel is a liquid crystal display panel, the internal light is light emitted by the backlight through the display device, and the direction thereof and the direction of the external light. On the other hand, if the display panel is an OLED display panel, the internal light is light emitted by the OLED display device, and the direction thereof is also opposite to the direction of the external light.

In an embodiment, the light collecting layer 103 is disposed between the substrate 101 and the display device 102 for condensing external light incident into the interior of the display panel, and includes a plurality of microlenses 1031 distributed in an array; the microlens 1031 is made of a transparent non-absorbent material, which may be, for example, a hemispherical shape including a top surface and a bottom surface, the bottom surface being a spherical surface, the top surface being a circular plane, the top surface facing the light absorbing layer 104, The bottom surface faces the substrate 101; wherein the microlens 1031 has a lower hemispherical shape along the incident direction of the external light, that is, the external light is incident from the bottom surface of the microlens 1031 and exits from the top surface. The plurality of microlenses 1031 are embedded inside the flat layer 105 of the upper surface of the substrate 101, and the top surfaces of each of the microlenses 1031 are located in the same plane, and each microlens 1031 has the same shape and size; the flat layer The refractive index of 105 is smaller than the refractive index of the microlens 1031, so that external light entering from below the substrate 101 can be incident on the light collecting point F of the microlens 1031 after being incident on the microlens 1031 through the flat layer 105. The light convergence point F is the focus of the microlens 1031, as shown in Fig. 3(a). As an example, the flat layer 105 has a refractive index between 1.4 and 1.6, and the microlens material 1031 has a refractive index between 1.65 and 2.0.

Optionally, the spacing between the plurality of microlenses 1031 is preferably greater than the diameter of a single microlens, such as the diameter of any one of the plurality of microlenses 1031, to avoid shading; The diameter of the microlens 1031 is smaller than the length and width of a single sub-pixel, and preferably 5-20 microlenses are fabricated under a single sub-pixel.

Optionally, the microlens 1031 is made of a transparent non-absorbent material, for example, one material selected from the following materials or a mixed material of a plurality of materials: polymethyl methacrylate, polymethyl methacrylate Polyacrylic resin such as ester or polycyclohexyl methacrylate, olefinic resin such as polydiethylene glycol bisallyl carbonate or polycarbonate, methacrylic resin, urethane resin, polyester resin, poly Vinyl chloride resin, polyvinyl acetate resin, fiber resin, polystyrene resin, and the like.

The light absorbing layer 104 is located at a focus position of the microlens 1031 for absorbing external light concentrated at a focus of the microlens 1031. The material of the light absorbing layer 104 is a black matrix light shielding material, such as carbon black, black resin, black titanium compound lacking an oxygen atom, etc.; the light absorbing layer 104 may be a rectangular square, a circle, etc., and the area thereof may be It is much smaller than the top surface area of the microlens 1031, for example, about one quarter of the microlens 1031, and the thickness of the light absorbing layer is 5 to 50 nm. If the thickness of the light absorbing layer is too thin, the effect of absorbing light is not obtained. If it is too thick, it will increase the thickness of the device. As can be seen from FIG. 1, the light absorbing layer 104 may be embedded inside the flat layer, and the light absorbing layer 104 is formed only at the focal position of each of the microlenses 1031, and the area of the light absorbing layer 104 is much smaller than that of the microlens. The area, therefore, has little effect on the internal light emerging from the display device 102. Since the light absorbing layer 104 is disposed at the focus of each of the microlenses 1031, the focal length of the microlens 1031 should not be too long, which may cause an increase in the thickness of the display panel.

FIG. 2 is a schematic structural view of a display panel according to a second embodiment of the present invention. As shown in FIG. 2, on the basis of the first embodiment, a light scattering layer 106 is disposed, which is located on a side of the light absorbing layer 104 facing the display device, which may be associated with the light absorbing layer. 104 contact arrangement, or a certain isolation layer between them, as long as the light scattering layer 106 can block above the light absorbing layer 104, the internal light of the display device irradiated to the light absorbing layer 104 can be scattered, the purpose is to Part of the internal light that is irradiated to the light absorbing layer is not absorbed by the light absorbing layer 104, so as not to lower the light extraction rate and brightness of the device.

The light scattering layer 106 is made of a transparent material doped with scattering particles, such as a transparent resin doped with scattering particles, and the like, and has a size equivalent to that of the light absorbing layer to completely block the absorbing layer. Precisely, the thickness can also be comparable to the light absorbing layer, and of course, it can be thinner. As long as the purpose of scattering internal light can be achieved. The light scattering layer 106 and the light absorbing layer 104 are both formed at the focal position of the microlens, as shown in FIG. 3(c), so that the area of the light scattering layer 106 and the light absorbing layer 104 can be made small, much smaller than the micro The upper surface area of the lens 1031 can prevent excessive emission light from being changed in the inside of the device, as shown in Fig. 3(b). At the same time, even if a part of the display device is internally illuminated onto the light absorbing layer 104, due to the presence of the upper light scattering layer 106, this portion of the light is not absorbed, but is scattered several times outside the device.

As an example, the scattering layer has a refractive index of between 1 and 3, and the scattering particles may be an inorganic material, an organic material, or a combination of an organic material and an inorganic material.

Alternatively, the display device 102 may be a liquid crystal display device, a bottom emission type OLED display device, or a top emission type OLED display device or the like.

The display panel of the invention provides a light collecting layer having a plurality of microlenses and an absorbing layer at a light concentrating position of the microlens for the purpose of absorbing external light entering the inside of the device and preventing external light from passing through the device top. When the electrode (such as in the case where the display device is an OLED) is reflected, the contrast is lowered, and the image quality of the display is lowered. Further, a scattering layer is further formed over the absorption layer in order to prevent the light emitted from the inside of the device from being Absorbed by the absorption layer, increasing the light output rate of the internal light of the device, ensuring that the light emitted inside the device is not blocked.

The present invention also proposes a display device comprising the display panel as described above. Optionally, the display device is a bottom emission type OLED display device.

The present invention also provides a method of fabricating a display panel, comprising: forming a substrate, a display device, and a light concentrating layer and a light absorbing layer between the substrate and the display device; wherein the light concentrating layer and the light absorbing layer are along the external light The incident directions are arranged in order, and the light collecting layer is used for collecting external light, and the light absorbing layer is located at the convergence of the external light for absorbing the concentrated external light.

The method for fabricating the display panel proposed by the present invention will be described in detail below through specific embodiments.

FIG. 4a is a flow chart showing a method for fabricating a display panel according to an embodiment of the invention. FIG. 5 is a flow chart showing a manufacturing process of a display panel according to an embodiment of the invention. As shown in Figure 4a (the dotted line in Figure 4a indicates optional steps) and 5, as an example, the method includes:

Step 401: Form a substrate 101, which may be a TFT array substrate or a glass substrate;

Step 402: forming a light collecting layer 103 on the substrate 101, as an example, the light collecting layer 103 may include a plurality of microlenses 1031 distributed in an array;

Step 403: forming a light absorbing layer 104 at an external light convergence area above the light collecting layer 103;

Step 405: Form display device 102.

As an example, as shown in FIG. 4b, the above step 402 may include:

Step 4021: forming a first flat layer 1051 on the substrate 101; Step 4022: forming a plurality of microlenses 1031 distributed in an array in the first flat layer 1051, for example, the first flat layer 1051 may be patterned to form a groove distributed in the array, the shape of the groove being the same as the shape of the microlens 1031 to be fabricated, as shown in FIG. 5(a), for example, in a groove formed on the first flat layer 1051 Forming a plurality of microlenses 1031 of an array distribution by a method such as a photoresist hot melt method, a chemical weather deposition method, an inkjet printing method, or the like, the plurality of microlenses 1031 having a hemispherical shape including a top surface and a bottom surface, wherein the bottom surface is a spherical surface, the top surface being a circular plane, and for example, each microlens has the same size and shape, and its top surface is in the same plane, as shown in FIG. 5(b); the microlens 1031 can be transparent and non-absorptive. The material is formed, for example, may be selected from one of the following materials or a mixed material of a plurality of materials: polyacrylic acid resin such as polymethyl methacrylate, polyethyl methacrylate, polycyclohexyl methacrylate or the like. , polydiethylene glycol double An allylic resin such as allyl carbonate or polycarbonate, a methacrylic resin, a urethane resin, a polyester resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a fiber resin, or a polystyrene resin. As an example, the refractive index of the material selected for the microlens 1031 needs to be greater than the refractive index of the flat layer material.

Step 4023: forming a second planar layer 1052 over the microlens 1031. As an example, the thickness may be equal to the distance from the top surface of the microlens 1031 to its focal point such that the upper surface of the second planar layer 1052 is formed. The light absorbing layer 104 is just at the focus position of the microlens 1031 as shown in Fig. 5(c).

As an example, step 403 may include forming, at a focus position of each of the microlenses 1031, a light absorbing layer 104 having an area smaller than the microlens by a solution method such as deposition or spraying, as shown in FIG. 5(d).

The light absorbing layer has a thickness of 5 to 50 nm, and the light absorbing layer material may be a light shielding material, such as carbon black, black resin, black titanium compound lacking one oxygen atom, and the like; the light absorbing layer will be The external light entering outside the device is absorbed at the focus of the microlens, preventing external light from being reflected by the top electrode of the device, causing a decrease in contrast and a reduction in image quality of the display.

In an embodiment, step 404 (shown by the dashed box in FIG. 4a) may be further included between step 403 and step 405: on the side of the light absorbing layer 104 facing the display device 102 (shown in the figure) The light scattering layer 106 is formed above, and the area of the light scattering layer 106 is substantially the same as that of the light absorbing layer 104.

As an example, step 404 can include:

Forming a light scattering layer 106 having an area substantially the same as that of the light absorbing layer 104 over the light absorbing layer 104 by using a mask;

A third flat layer 1053 is formed on the light scattering layer 106 as shown in FIG. 5(e).

The light scattering layer 106 may be made of a transparent material doped with scattering particles, such as a transparent resin or the like. The scattering particles include an organic material, an inorganic material, and a combination of the two. The purpose of fabricating the light-scattering layer is to absorb the light inside the portion of the light-absorbing layer that is not absorbed by the light-absorbing layer, so as not to lower the light-emitting rate and brightness of the device.

As an example, step 405 may include fabricating display device 102 over said third planar layer 1053 to complete fabrication of the entire display panel, as shown in Figure 5(f).

The invention adopts a scheme in which a microlens is combined with an absorbing layer and a scattering layer, so that the reflection of external light inside the device is effectively reduced, and at the same time, the illumination inside the device is not blocked, that is, the brightness of the device is not attenuated, which is Compared with the conventional method of attaching a polarizer, the brightness is obviously improved; the invention also saves the production cost, reduces the thickness of the display panel, and reduces the risk of the yield drop caused by the polarizer attached.

The specific embodiments of the present invention have been described in detail in the foregoing detailed description of the embodiments of the present invention. All modifications, equivalents, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

A display panel includes a substrate, a display device, and a light collecting layer and a light absorbing layer between the substrate and the display device, wherein the light collecting layer and the light absorbing layer are sequentially arranged along an incident direction of external light, and the light is concentrated. The layer is for collecting external light, and the light absorbing layer is located at the convergence of the external light for absorbing the concentrated external light.
The display panel of claim 1, wherein the light converging layer comprises a plurality of microlenses distributed in an array.
The display panel according to claim 2, wherein the microlens is in a hemispherical shape, and includes a top surface and a bottom surface, the bottom surface is a spherical surface, the top surface is a circular plane, and the top surface faces the light absorbing layer. The bottom surface faces the substrate.
The array panel of claim 2, wherein a spacing between the plurality of microlenses is greater than a diameter of a single microlens.
The display panel according to any one of claims 2 to 4, wherein the microlens is made of a transparent non-light absorbing material.
The display panel according to claim 5, wherein the microlens is made of a polyacrylic resin, an acryl resin, a methacrylic resin, a urethane resin, a polyester resin, a polyvinyl chloride resin, a polyvinyl acetate resin, or a fiber. One of a resin or a polystyrene resin is made of or mixed with a plurality of materials.
The display panel according to any one of claims 2 to 6, further comprising a flat layer, the microlens being embedded inside the flat layer, and the flat layer material has a refractive index smaller than a refractive index of the microlens material.
The display panel according to any one of claims 2 to 6, wherein the light absorbing layer is located at a focus position of the microlens.
The display panel according to claim 8, wherein an area of the light absorbing layer is smaller than an area of the microlens.
The display panel according to any one of claims 1 to 9, wherein the light absorbing layer is one of carbon black, black resin, black titanium compound lacking one oxygen atom, or a mixture thereof. .
The display panel according to any one of claims 1 to 9, further comprising a light scattering layer on a side of the light absorbing layer facing the display device for scattering light inside the display device.
The display panel according to claim 11, wherein the light scattering layer is made of a transparent material doped with scattering particles.
The display panel according to claim 11, wherein the light scattering layer has the same area as the light absorbing layer.
A display device comprising the display panel of any of claims 1-13.
A method of manufacturing a display panel, comprising:

Forming a substrate, a display device, and a light concentrating layer and a light absorbing layer between the substrate and the display device; wherein the light concentrating layer and the light absorbing layer are sequentially arranged along an incident direction of external light, the light concentrating layer For concentrating external light, the light absorbing layer is located at the convergence of the external light for absorbing the concentrated external light.
The method of fabricating a display panel according to claim 15, wherein the forming the substrate, the display device, and forming the light collecting layer and the light absorbing layer between the substrate and the display device comprises:

Forming the substrate;

Forming the light converging layer on the substrate;

Forming the light absorbing layer at an external light concentrating layer above the light concentrating layer;

The display device is formed.
The method of manufacturing a display panel according to claim 16, wherein the forming the light collecting layer on the substrate comprises:

Forming a first planar layer on the substrate;

Forming a plurality of microlenses distributed in an array in the first planar layer;

A second planar layer is formed over the microlens.
The method of manufacturing a display panel according to claim 17, wherein the microlens is made of a transparent non-light absorbing material and has a refractive index greater than a refractive index of the flat layer.
The method of fabricating a display panel according to claim 16, wherein the forming the light absorbing layer at an external light concentrating layer above the light concentrating layer comprises:

A light absorbing layer having an area smaller than that of the microlens is formed at a focus position of each of the microlenses.
The method of manufacturing a display panel according to any one of claims 15 to 19, further comprising:

A light scattering layer having the same area as the light absorbing layer is formed on a side of the light absorbing layer facing the display device, and the light scattering layer is made of a transparent material doped with scattering particles.