TWI826140B - Display panel - Google Patents

Abstract

A display panel including a substrate, a display layer, a first electrode, a transparent dielectric layer, a cholesteric liquid crystal layer and a second electrode is provided. The display layer is disposed on the substrate. The display layer includes a plurality of light emitting elements arranged in an array. The first electrode is disposed over the display layer. The transparent dielectric layer is disposed on the first electrode and has a plurality of openings. A portion of the transparent dielectric layer corresponds to the plurality of light emitting elements of the display layer. The cholesteric liquid crystal layer is disposed in the plurality of opening. The second electrode is disposed on the transparent dielectric layer and the cholesteric liquid crystal layer.

Description

display panel

The present invention relates to a panel, and in particular to a display panel.

With the advancement of technology, display panels are commonly used in mobile phones, TV screens, automotive panels and other applications. In order to improve the quality of the display panel, in addition to including a display for general display purposes, the display panel can also be bonded with a decorative film substrate on the display to provide decoration. However, when the decorative film substrate is in the foggy off mode, it may still affect the image display of the monitor, resulting in reduced image clarity. In order to display the image clearly on the display, a high electric field needs to be applied to the decorative film substrate, which consumes more power.

The present invention provides a display panel, which has clear image display and decoration functions and takes into account energy saving effects.

The display panel of the present invention includes a substrate, a display layer, a first electrode, a transparent dielectric layer, a cholesteric liquid crystal layer and a second electrode. The display layer is arranged on the substrate. The display layer includes a plurality of light-emitting units arranged in an array. The first electrode is disposed on the display layer. The transparent dielectric layer is disposed on the first electrode and has a plurality of openings, and part of the transparent dielectric layer corresponds to the plurality of light-emitting units of the display layer. The cholesteric liquid crystal layer is disposed in a plurality of openings. The second electrode is disposed on the transparent dielectric layer and the cholesteric liquid crystal layer.

In an embodiment of the present invention, the above-mentioned display panel further includes a plurality of filling structures disposed in a plurality of openings and located between the cholesteric liquid crystal layer and the first electrode.

In an embodiment of the present invention, the plurality of filling structures have different heights, and the sum of the height of each filling structure and the height of the corresponding cholesteric liquid crystal layer is substantially equal to the depth of the plurality of openings.

In an embodiment of the present invention, the orthographic projection of the above-mentioned cholesteric liquid crystal layer on the substrate does not overlap with the orthographic projection of the light-emitting unit on the substrate.

In an embodiment of the present invention, the orthographic projection of the above-mentioned transparent dielectric layer on the substrate at least partially overlaps with the orthographic projection of the light-emitting unit on the substrate.

In an embodiment of the present invention, the above-mentioned transparent dielectric layer has a mesh structure or a plurality of island structures.

In an embodiment of the present invention, the material of the transparent dielectric layer is an organic transparent photoresist material.

In an embodiment of the present invention, the above-mentioned display layer further includes blocking walls to separate the plurality of light-emitting units.

In an embodiment of the present invention, the above-mentioned cholesteric liquid crystal layer corresponds to the retaining wall.

In an embodiment of the present invention, the plurality of light-emitting units include micro-light-emitting diodes or organic light-emitting diodes.

Based on the above, the display panel of the present invention provides a transparent dielectric layer corresponding to the light-emitting unit in the cholesterol liquid crystal layer, so that the picture of the display layer will not be blocked by the cholesterol liquid crystal molecules, and can present a clear display picture, and the display layer In the display mode, the cholesteric liquid crystal layer can be in the focal cone state without maintaining the vertical state, thereby achieving the purpose of saving power.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Throughout this specification, the same reference numbers refer to the same elements. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or Intermediate elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connection. Furthermore, "electrical connection" or "coupling" may mean the presence of other components between the two components.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited thereto. limitations of these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a "first element," "component," "region," "layer" or "section" discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

FIG. 1A is a schematic cross-sectional view of a display panel according to an embodiment of the present invention. Figure 1B is a schematic top view of an embodiment along the cross-section line A-A' of Figure 1A. Fig. 1C is a schematic top view of an embodiment along the cross-section line B-B' of Fig. 1A. Figure 1D is a schematic top view of another embodiment along the cross-section line B-B' of Figure 1A.

Referring to FIGS. 1A to 1D , the display panel 10 includes a substrate 100 (also called a first substrate 100 ), a display layer 110 , a first electrode 122 , a transparent dielectric layer 130 , a cholesteric liquid crystal layer 140 and a second electrode 152 . The display layer 110 is provided on the first substrate 100 . The display layer 110 includes a plurality of light emitting units 112 arranged in an array. The first electrode 122 is disposed on the display layer 110 . The transparent dielectric layer 130 is disposed on the first electrode 122 and has a plurality of openings OP1 , and part of the transparent dielectric layer 130 corresponds to the plurality of light-emitting units 112 of the display layer 110 . The cholesteric liquid crystal layer 140 is provided in the plurality of openings OP1. The second electrode 152 is disposed on the transparent dielectric layer 130 and the cholesteric liquid crystal layer 140 .

The material of the first substrate 100 may be glass, quartz, organic polymer or other applicable materials, and the present invention is not limited thereto. In some embodiments, the first substrate 100 is a flexible substrate, and the material of the first substrate 100 is, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN). ), polyester (PES), polymethylmethacrylate (PMMA), polycarbonate (PC), polyimide (PI) or other flexible materials.

The first substrate 100 may be provided with circuit components for implementing display functions or transmitting electrical signals, such as a plurality of pixel circuits (not shown) arranged in an array and signal lines (not shown) electrically connected to the corresponding pixel circuits. (not shown). In some embodiments, the first substrate 100 may further be provided with power lines, common signal lines and other signal lines (not shown), which are used to provide power signals and common signals to the pixel circuits.

The plurality of light-emitting units 112 of the display layer 110 are disposed on the first substrate 100 and are electrically connected to the pixel circuit accordingly. The plurality of light-emitting units 112 (such as the light-emitting units 112a, 112b and 112c) can emit light of different colors. For example, the light-emitting unit 112a can emit red light, the light-emitting unit 112b can emit green light, and the light-emitting unit 112c can emit blue light. However, the present invention is not limited to this. It should be understood that the number, arrangement and color of the light-emitting units can be adjusted according to actual needs, and the present invention is not limited thereto.

In some embodiments, the display layer 110 further includes blocking walls 114 disposed on the first substrate 100 to separate the plurality of light-emitting units 112 . For example, the retaining wall 114 may be a mesh structure (as shown in FIG. 1B ), which has a plurality of openings OP2 , and a plurality of light-emitting units 112 are disposed in the plurality of openings OP2 .

In some embodiments, the light emitting unit 112 may be an organic light emitting diode. For example, the light-emitting unit 112 may include an anode (not shown), an organic light-emitting stack (not shown), and a cathode (not shown) disposed on the first substrate 100 . The organic light-emitting stack may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. sequentially disposed on the anode, but the invention is not limited thereto. The number and type of organic light-emitting stacks Can be adjusted according to actual needs. In other embodiments, the light emitting unit 112 may be a micro light emitting diode.

In some embodiments, the display panel 10 further includes a second substrate 120 . The second substrate 120 is disposed on the display layer 110 to serve as a packaging cover of the display layer 110 . In some embodiments, the first substrate 100, the display layer 110 and the second substrate 120 may constitute the display module 10'.

The first electrode 122 may be disposed on a side of the second substrate 120 opposite to the display layer 110 , that is, the second substrate 120 is located between the display layer 110 and the first electrode 122 .

In some embodiments, the display panel 10 further includes a third substrate 150 disposed on the second electrode 152 . The second electrode 152 is located between the third substrate 150 and the cholesteric liquid crystal layer 140 and the transparent dielectric layer 130 . In some embodiments, a protective film (not shown) may be provided on one side of the third substrate 150 relative to the second electrode 152 to protect the display panel 10 and reduce damage due to scratches.

In some embodiments, the material of the first electrode 122 and the second electrode 152 may be a transparent conductive material, such as indium tin oxide (ITO), gallium-doped zinc oxide (GZO), The invention is not limited to aluminum-doped zinc oxide (AZO) or other suitable transparent conductive materials. Although a whole layer of first electrode 122 and second electrode 152 is shown in FIG. 1A , this is not intended to limit the present invention. The first electrode and second electrode 152 can have a patterned design according to actual requirements.

In some embodiments, the transparent dielectric layer 130 is an organic transparent photoresist material, including, for example, acrylate, propylene glycol methyl ether acetate, a combination of the above materials, or other suitable organic resins.

The cholesteric liquid crystal layer 140 can be used as a decorative mold layer and is located between the first electrode 122 and the second electrode 152 . By applying an electric field to the cholesteric liquid crystal layer 140 through the first electrode 122 and the second electrode 152, the liquid crystal state of the cholesteric liquid crystal layer 140 can be controlled to control the on/off state of the decoration mode. For example, when the cholesteric liquid crystal layer 140 is in a planar state, it can reflect incident light and reflect the image of the cholesteric liquid crystal layer 140. At this time, the decoration mode can be regarded as an on state. If a low electric field is applied to the cholesteric liquid crystal layer 140 in the planar state, it can be changed to a focal conic state, causing the incident light to scatter and appear in a hazy state. The display layer located below the cholesteric liquid crystal layer 140 can be displayed. 110 screen, the decoration mode is considered to be off at this time. If a high electric field is applied to the cholesterol liquid crystal layer 140 in the planar state, all the cholesterol liquid crystal molecules in the cholesterol liquid crystal layer 140 can be arranged vertically and converted into a vertical state, so that the incident light can be completely transmitted to show that the molecules located below the cholesterol liquid crystal layer 140 The picture of the display layer 110 is shown, and the decoration mode is turned off at this time.

In some embodiments, the wavelength range that the cholesteric liquid crystal layer 140 can reflect can be adjusted by adjusting the pitch of the cholesteric liquid crystal layer 140 , that is, the color reflected by the cholesteric liquid crystal layer 140 can be adjusted.

In some embodiments, the cholesteric liquid crystal layer 140 fills the plurality of openings OP1 of the transparent dielectric layer 130 .

In some embodiments, the orthographic projection of the transparent dielectric layer 130 on the first substrate 100 at least partially overlaps the orthographic projection of the light emitting unit 112 on the first substrate 100 . That is to say, from another perspective, the orthographic projection of the cholesteric liquid crystal layer 140 on the first substrate 100 does not overlap with the orthographic projection of the light-emitting unit 112 on the first substrate 100 , that is, the position of the cholesteric liquid crystal layer 140 is different from the blocking wall. 114 corresponds. For example, as shown in FIG. 1C , the transparent dielectric layer 130 has a mesh structure, so that the cholesteric liquid crystal layer 140 is separated into multiple blocks, but the invention is not limited to this. In other embodiments, as shown in FIG. 1D , the transparent dielectric layer 130 is a plurality of island-shaped structures, and their orthographic projections on the first substrate 100 respectively overlap with the orthographic projections of the light-emitting units 112 on the substrate 100 .

Since the light-emitting unit 112 is disposed corresponding to the transparent dielectric layer 130 and does not overlap with the cholesteric liquid crystal layer 140 , the image of the display layer 110 can directly pass through the transparent dielectric layer 130 without passing through the cholesteric liquid crystal layer 140 . In this way, when the display layer 110 is in the display mode, the cholesteric liquid crystal layer 140 can be in the focal cone state without maintaining the vertical state, and the picture of the display layer 110 can directly pass through the transparent dielectric layer 130 without being affected by the cholesterol. The blocking of liquid crystal molecules makes the image displayed by the display layer 110 clear and achieves the purpose of saving power at the same time.

FIG. 2 is a schematic cross-sectional view of a display panel according to another embodiment of the present invention. It must be noted here that the embodiment of FIG. 2 follows the component numbers and part of the content of the embodiment of FIG. 1A , where the same or similar numbers are used to represent the same or similar elements, and the description of the same technical content is omitted. For descriptions of omitted parts, reference may be made to the foregoing embodiments and will not be described again here.

Referring to FIG. 2 , the display panel 20 of this embodiment is different from the embodiment of FIG. 1A in that the display panel 20 further includes a plurality of filling structures 142 , which are disposed in a plurality of openings OP1 and located between the cholesteric liquid crystal layer 140 and the between the first electrodes 122 . The material of the filling structure 142 may include epoxy resin or other materials suitable for forming through inkjet printing technology for filling and flattening purposes, and is not limited by the present invention. In some embodiments, filling structure 142 is a transparent structure.

The plurality of filling structures 142 can have different heights to adjust the thickness of the corresponding cholesteric liquid crystal layer 140 and thereby adjust the brightness of the corresponding cholesteric liquid crystal layer 140 . For example, the higher the thickness of the corresponding cholesteric liquid crystal layer 140, the lower the thickness of the corresponding filling structure 142, and the stronger the reflection intensity, the brighter the cholesteric liquid crystal layer 140; conversely, the lower the thickness of the cholesteric liquid crystal layer 140. , the higher the thickness of the corresponding filling structure 142 and the weaker the reflection intensity, the darker the cholesteric liquid crystal layer 140 is. FIG. 2 only schematically illustrates the relative relationship between the filling structure 142 and the cholesterol liquid crystal layer 140, but is not intended to limit the present invention. The thickness design of each filling structure 142 can be adjusted according to actual needs, and some openings OP1 may not be provided. Fill structure.

In some embodiments, the sum of the thickness of each filling structure 142 and the thickness of its corresponding cholesteric liquid crystal layer 140 is substantially equal to the depth of the opening OP1.

3A to 3C are schematic cross-sectional views of a manufacturing process of a display panel according to an embodiment of the present invention. It must be noted here that the embodiments of FIGS. 3A to 3C follow the component numbers and part of the content of the embodiment of FIG. 2 , where the same or similar numbers are used to represent the same or similar elements, and references with the same technical content are omitted. instruction. For descriptions of omitted parts, reference may be made to the foregoing embodiments and will not be described again here.

Referring to FIG. 3A, a display module 10' is provided. The display module 10' includes a first substrate 100, a display layer 110 and a second substrate 120. The first electrode 122 is formed on the second substrate 120 . Then, a transparent dielectric layer 130 is formed on the first electrode 122 . For example, a transparent dielectric material layer can be coated on the first electrode 122, and then the opening OP1 is defined through a photolithography process to form the transparent dielectric layer 130.

Referring to FIG. 3B , filling structures 142 are formed in a plurality of openings OP1 . The method of forming the filling structure 142 includes an inkjet printing process. For example, liquid filling material (not shown) can be sprayed into the plurality of openings OP1, and then the filling material can be solidified through a vacuum drying process to form the filling structure 142. In some embodiments, filling structures 142 with different heights can be formed by spraying different amounts of filling material in different openings OP1. In other embodiments, the partial opening OP1 may not form a filling structure.

Referring to FIG. 3C , a cholesteric liquid crystal layer 140 is formed in the filling structure 142 and located in the plurality of openings OP1. The method of forming the cholesteric liquid crystal layer 140 includes an inkjet printing process. In some embodiments, the cholesteric liquid crystal layer 140 may fill the plurality of openings OP1 such that the sum of the thickness of each filling structure 142 and the thickness of its corresponding cholesteric liquid crystal layer 140 is substantially equal to the depth of the opening OP1 .

After that, please refer to FIG. 2 to dispose the second electrode 152 and the third substrate 150 on the cholesteric liquid crystal layer 140 and the transparent dielectric layer 130. For example, the second electrode 152 can be formed on the third substrate 150 first, and then the third substrate 150 on which the second electrode 152 is formed is bonded to the cholesteric liquid crystal layer 140 and the transparent dielectric layer 130, so that the third substrate 150 can be formed on the third substrate 150. The two electrodes 152 are disposed between the third substrate 150 and the cholesteric liquid crystal layer 140 and the transparent dielectric layer 130 .

After the above process, the production of the display panel 20 can be roughly completed. The manufacturing process of the display panel 10 is similar to the manufacturing process of the display panel 20 described above, except that the display panel 10 does not need to go through the step of forming a filling structure.

To sum up, the display panel of the present invention disposes a transparent dielectric layer corresponding to the light-emitting unit in the cholesterol liquid crystal layer, so that the picture of the display layer will not be blocked by the cholesterol liquid crystal molecules, and can present a clear display picture, and When the display layer is in the display mode, the cholesteric liquid crystal layer can be in a focal cone state without maintaining a vertical state, thereby achieving the purpose of saving power.

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the appended patent application scope.

10,20:Display panel 10’:Display module 100:Substrate/first substrate 110:Display layer 112,112a,112b,112c: Light emitting unit 114: retaining wall 120: Second substrate 122:First electrode 130:Transparent dielectric layer 140: Cholesterol liquid crystal layer 142:Padding structure 150:Third substrate 152:Second electrode A-A’,B-B’: Sectional line OP1, OP2: Open

FIG. 1A is a schematic cross-sectional view of a display panel according to an embodiment of the present invention. Figure 1B is a schematic top view of an embodiment along the cross-section line A-A' of Figure 1A. Fig. 1C is a schematic top view of an embodiment along the cross-section line B-B' of Fig. 1A. Figure 1D is a schematic top view of another embodiment along the cross-section line B-B' of Figure 1A. FIG. 2 is a schematic cross-sectional view of a display panel according to another embodiment of the present invention. 3A to 3C are schematic cross-sectional views of a manufacturing process of a display panel according to an embodiment of the present invention.

10:Display panel

10’:Display module

100:Substrate/first substrate

110:Display layer

112,112a,112b,112c: Light emitting unit

114: retaining wall

120: Second substrate

122:First electrode

130:Transparent dielectric layer

140: Cholesterol liquid crystal layer

150:Third substrate

152:Second electrode

A-A’,B-B’: Sectional line

OP1, OP2: Open

Claims (10)

A display panel including: a substrate; A display layer is provided on the substrate, the display layer includes a plurality of light-emitting units arranged in an array; a first electrode disposed on the display layer; A transparent dielectric layer is disposed on the first electrode and has a plurality of openings, and part of the transparent dielectric layer corresponds to the plurality of light-emitting units of the display layer; A cholesteric liquid crystal layer is disposed in the plurality of openings; A second electrode is provided on the transparent dielectric layer and the cholesteric liquid crystal layer. The display panel as described in request item 1 further includes: A plurality of filling structures are disposed in the plurality of openings and located between the cholesteric liquid crystal layer and the first electrode. The display panel of claim 2, wherein the plurality of filling structures have different heights, and the sum of the height of each of the plurality of filling structures and the height of the corresponding cholesteric liquid crystal layer is substantially equal to the height of the plurality of openings. depth. The display panel of claim 1, wherein the orthographic projection of the cholesteric liquid crystal layer on the substrate does not overlap with the orthographic projection of the light-emitting unit on the substrate. The display panel of claim 1, wherein an orthographic projection of the transparent dielectric layer on the substrate at least partially overlaps with an orthographic projection of the light-emitting unit on the substrate. The display panel of claim 1, wherein the transparent dielectric layer is a mesh structure or a plurality of island structures. The display panel according to claim 1, wherein the material of the transparent dielectric layer is an organic transparent photoresist material. The display panel of claim 1, wherein the display layer further includes a blocking wall to separate the plurality of light-emitting units. The display panel of claim 8, wherein the cholesteric liquid crystal layer corresponds to the blocking wall. The display panel of claim 1, wherein the plurality of light-emitting units include micro-light-emitting diodes or organic light-emitting diodes.

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