Electronic paper

Abstract

Electronic paper comprises an array substrate, a color film substrate, a liquid crystal layer and a cofferdam structure, the color film substrate and the array substrate are oppositely arranged in a spaced mode, the liquid crystal layer is arranged between the array substrate and the color film substrate, the cofferdam structure is arranged between the array substrate and the color film substrate and penetrates through the liquid crystal layer, a plurality of first grooves are formed in the array substrate, and a plurality of second grooves are formed in the cofferdam structure. One end of the cofferdam structure is connected with the color film substrate, the other end of the cofferdam structure extends into the multiple first grooves, and / or the color film substrate is provided with multiple second grooves, one end of the cofferdam structure is connected with the array substrate, and the other end of the cofferdam structure extends into the multiple second grooves, so that on the premise that the height of the cofferdam structure is not reduced, the distance between the array substrate and the color film substrate is reduced, and the yield of the array substrate is increased. Therefore, the problem of driving failure of the electronic paper caused by overlarge box thickness is avoided, and the yield of the electronic paper is improved.

Description

Technical Field

[0001] This invention relates to the field of cholesteric liquid crystal electronic paper technology, and specifically to an electronic paper. Background Technology

[0002] Currently, while electronic paper is widely used in static displays due to its advantages such as bistable operation and low power consumption, mainstream products are still limited to monochrome displays, hindering application expansion. Although color solutions exist, they generally suffer from bottlenecks in response speed and contrast. While cholesteric liquid crystal electronic paper has a significant advantage in response speed, its commonly used triple-stacked color structure suffers from low luminous efficiency, structural complexity, and high cost. To improve luminous efficiency, the industry has proposed using inkjet printing to prepare RGB parallel single-cell structures. However, this process leads to excessive cell thickness, resulting in excessive distance between pixel electrodes and common electrodes, insufficient electric field, and ultimately, the product failing to light up. Summary of the Invention

[0003] The purpose of this invention is to provide an electronic paper that solves the problem that excessive cell thickness of a single-layer liquid crystal leads to excessive distance between the pixel electrode and the common electrode, insufficient electric field, and ultimately causes the product to fail to light up.

[0004] To achieve the objectives of this invention, the following technical solution is provided: This invention provides an electronic paper comprising an array substrate; a color filter substrate disposed at a distance from the array substrate; a liquid crystal layer disposed between the array substrate and the color filter substrate; and a dam structure disposed between the array substrate and the color filter substrate and passing through the liquid crystal layer; wherein the array substrate has a plurality of first grooves, one end of the dam structure is connected to the color filter substrate, and the other end extends into the plurality of first grooves, and / or the color filter substrate has a plurality of second grooves, one end of the dam structure is connected to the array substrate, and the other end extends into the plurality of second grooves.

[0005] In one embodiment, the array substrate has a plurality of first grooves, one end of the dam structure is connected to the color filter substrate, and the other end extends into the plurality of first grooves; the array substrate includes a first substrate, a boss layer and a plurality of pixel electrodes, the boss layer is disposed on the side of the first substrate facing the color filter substrate and has a plurality of first grooves, and the plurality of pixel electrodes are disposed at intervals on the side of the boss layer facing away from the first substrate and are all located on the outer periphery of the first grooves.

[0006] In one embodiment, the boss layer includes a connecting portion and a plurality of protrusions. The connecting portion is stacked on the first substrate, and the plurality of protrusions are spaced apart from each other on the surface of the connecting portion facing away from the first substrate. A first groove is provided between any two adjacent protrusions, and the plurality of pixel electrodes are stacked on the plurality of protrusions in a one-to-one correspondence.

[0007] In one embodiment, the color filter substrate has a plurality of second grooves, one end of the dam structure is connected to the array substrate, and the other end extends into the plurality of second grooves; the color filter substrate includes a second substrate and a plurality of common electrodes, the plurality of common electrodes are spaced apart on the side of the second substrate facing the array substrate, and there is a second groove between any two adjacent common electrodes.

[0008] In one embodiment, the color filter substrate further includes a plurality of protrusions, which are disposed on the side of the second substrate facing the array substrate, and a plurality of common electrodes are stacked on the plurality of protrusions in a one-to-one correspondence.

[0009] In one embodiment, the plurality of common electrodes are connected one-to-one with the outer peripheral surfaces of the plurality of protrusions and the second substrate.

[0010] In one embodiment, the array substrate includes a first substrate, a plurality of pixel electrodes and a back coating layer. The first substrate and the second substrate are disposed opposite to each other, the plurality of pixel electrodes are disposed at intervals on the side of the first substrate facing the second substrate, and the back coating layer is stacked on the side of the first substrate facing away from the second substrate.

[0011] In one embodiment, the array substrate further includes a planarization layer disposed on the side of the plurality of pixel electrodes facing away from the first substrate, and the dike structure is connected to the planarization layer.

[0012] In one embodiment, the liquid crystal layer comprises a plurality of cholesteric liquid crystals located on the same layer and spaced apart from each other.

[0013] In one embodiment, the cofferdam structure includes a main body and a plurality of protrusions. One or both ends of the main body are connected to the plurality of protrusions. The main body is disposed between the array substrate and the color filter substrate and passes through the liquid crystal layer.

[0014] The electronic paper provided by this invention comprises an array substrate, a color filter substrate, a liquid crystal layer, and a dam structure. The color filter substrate and the array substrate are arranged at intervals relative to each other. The liquid crystal layer is disposed between the array substrate and the color filter substrate. The dam structure is disposed between the array substrate and the color filter substrate and passes through the liquid crystal layer. The array substrate has multiple first grooves. One end of the dam structure is connected to the color filter substrate, and the other end extends into the multiple first grooves. And / or, the color filter substrate has multiple second grooves. One end of the dam structure is connected to the array substrate, and the other end extends into the multiple second grooves. This reduces the spacing between the array substrate and the color filter substrate without reducing the height of the dam structure, thereby avoiding the problem of electronic paper driving failure caused by excessive cell thickness and improving the yield of electronic paper. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a cross-section of electronic paper in proportion. Figure 2 This is a cross-sectional schematic diagram of an embodiment of electronic paper; Figure 3 This is a cross-sectional schematic diagram of electronic paper according to another embodiment; Figure 4 This is a cross-sectional schematic diagram of electronic paper according to yet another embodiment; Figure 5 This is a cross-sectional schematic diagram of electronic paper in another embodiment.

[0017] Explanation of reference numerals in the attached figures: 100-Electronic Paper; 10-Array substrate, 11-First substrate, 12-Pixel electrode, 13-Protrusion layer, 131-Connection portion, 132-Protrusion portion, 14-Back coating layer, 15-Planar layer, 16-First groove; 20-Color filter substrate, 21-Second substrate, 22-Common electrode, 23-Second groove; 30-Liquid crystal layer, 31-Cholesteric liquid crystal; 40-cofferdam structure, 41-main body, 411-receiving cavity, 42-protrusion. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.

[0020] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0021] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] Please refer to Figure 1 , Figure 1 The image shown is a cross-sectional schematic diagram of a comparative electronic paper 100. Figure 1 In the electronic paper 100, there are a color filter substrate 20 and an array substrate 10 disposed opposite to each other, and a cholesteric liquid crystal layer 31 and a dam structure 40 disposed between the array substrate 10 and the color filter substrate 20. Since the electronic paper 100 is a single-layer liquid crystal structure, that is, the liquid crystals used to reflect different colors of light are all located in the same layer, so as to improve the utilization rate of ambient light and improve the display effect of the electronic paper 100. However, this single-layer liquid crystal structure relies on high-precision inkjet printing technology for preparation. However, during the inkjet printing process, the dam structure 40 prepared to achieve inkjet printing will significantly increase the cell thickness between the array substrate 10 and the color filter substrate 20, resulting in the ITO electrode distance between the upper and lower substrates being too far. The resulting electric field strength is insufficient to effectively drive the liquid crystal molecules, ultimately causing the product to fail to light up.

[0023] To address the shortcomings of the electronic paper 100 in the comparative example described above, the present invention provides an electronic paper 100, please refer to... Figures 2 to 5The electronic paper 100 includes an array substrate 10, a color filter substrate 20, a liquid crystal layer 30, and a dam structure 40. The color filter substrate 20 is disposed at a distance from the array substrate 10. The liquid crystal layer 30 is disposed between the array substrate 10 and the color filter substrate 20. The dam structure 40 is disposed between the array substrate 10 and the color filter substrate 20 and passes through the liquid crystal layer 30. The array substrate 10 has a plurality of first grooves 16. One end of the dam structure 40 is connected to the color filter substrate 20, and the other end extends into the plurality of first grooves 16. And / or, the color filter substrate 20 has a plurality of second grooves 23. One end of the dam structure 40 is connected to the array substrate 10, and the other end extends into the plurality of second grooves 23.

[0024] In a specific embodiment, the array substrate 10 includes a first substrate 11 and a driving circuit layer stacked on the first substrate 11. The color filter substrate 20 includes a second substrate 21 and a plurality of common electrodes 22. The first substrate 11 and the second substrate 21 are disposed at intervals relative to each other. The driving circuit layer includes a plurality of pixel electrodes 12 and a plurality of driving circuits. The plurality of pixel electrodes 12 are disposed at intervals on the side of the first substrate 11 facing the second substrate 21 and are arranged in an array. The plurality of common electrodes 22 are disposed at intervals on the side of the second substrate 21 facing the first substrate 11 and are arranged in an array. The pixel electrode 12 and multiple common electrodes 22 are arranged opposite each other in the stacking direction. The liquid crystal layer 30 includes multiple cholesteric liquid crystals 31 located in the same layer and spaced apart from each other. A cholesteric liquid crystal 31 is disposed between any opposite pixel electrode 12 and a common electrode 22. Multiple driving lines are connected to the corresponding pixel electrode 12 to output voltage to the pixel electrode 12. The common electrode 22 is used to input a common voltage. The cholesteric liquid crystal 31 is used to change its arrangement direction under the action of the electric field formed between the corresponding pixel electrode 12 and the common electrode 22, thereby realizing the switching of optical state.

[0025] In a specific embodiment, the dam structure 40 includes a main body 41, which is disposed between the color filter substrate 20 and the array substrate 10 and passes through the liquid crystal layer 30. Specifically, the main body 41 encloses a plurality of mutually isolated and arrayed receiving cavities 411, in which a plurality of cholesteric liquid crystals 31 are received one-to-one within the receiving cavities 411, thereby isolating the plurality of cholesteric liquid crystals 31 from each other and preventing mutual interference, while also isolating the plurality of cholesteric liquid crystals 31 from the outside of the electronic paper 100. In a specific embodiment, the dam structure 40 also includes a plurality of protrusions 42, with a plurality of protrusions 42 connected to one or both ends of the main body 41, and the plurality of protrusions 42 are correspondingly disposed with a plurality of first grooves 16 and / or a plurality of second grooves 23.

[0026] Optionally, the first substrate 11 may be made of materials such as glass and quartz, and other structures on the first substrate 11 (e.g., a buffer layer), or it may be made of materials such as polyimide (PI), polyvinyl naphthalene (PEN), and polyethylene terephthalate (PET), without limitation. For example, the first substrate 11 may be made of glass, which has a low coefficient of thermal expansion, low density, and high chemical stability, to ensure that the deformation and warping of the glass substrate are smaller during processing and use, and that it is less prone to appearance changes due to material decomposition when subjected to corrosion by various acidic and alkaline chemical agents or gases. Optionally, the thickness of the first substrate 11 may be 0.3 mm to 0.7 mm, specifically 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc., without limitation. Optionally, the material of the second substrate 21 may be similar to that of the first substrate 11, and will not be described in detail. For example, the second substrate 21 may be made of a flexible polyimide (PI) material.

[0027] Optionally, the metal structure in the driving circuit layer can be made of metals such as molybdenum, aluminum, aluminum-nickel alloy, molybdenum-tungsten alloy, chromium, or copper, or a combination of the above-mentioned thin films, without limitation. The semiconductor structure in the driving circuit layer can be made of amorphous silicon, polycrystalline silicon, metal oxide, etc., without limitation. The insulating structure in the driving circuit layer can be made of inorganic materials such as silicon nitride, silicon oxide, and silicon oxynitride, without limitation. Optionally, the material of the common electrode 22 can be indium tin oxide (ITO), or silver nanowires, graphene, carbon nanotubes, etc., without limitation.

[0028] Optionally, the cofferdam structure 40 may be made of polyimide photoresist, epoxy resin photoresist, acrylate photoresist, or negative photoresist, without restriction.

[0029] In one implementation method, please refer to Figure 2 , Figure 2The diagram shown is a cross-sectional view of the electronic paper 100 of the first embodiment. The array substrate 10 has a plurality of first grooves 16. One end of the dam structure 40 is connected to the color filter substrate 20, and the other end extends into the plurality of first grooves 16. The array substrate 10 also includes a boss layer 13. The boss layer 13 is disposed on the side of the first substrate 11 facing the color filter substrate 20 and has a plurality of first grooves 16. A plurality of pixel electrodes 12 are disposed at intervals on the side of the boss layer 13 facing away from the first substrate 11 and are all located on the outer periphery of the first grooves 16. Specifically, the aforementioned cofferdam structure 40 has multiple protrusions 42 connected to one end of the main body 41 near the array substrate 10. Multiple first grooves 16 are arranged in an array and are corresponding one-to-one with the multiple protrusions 42 of the cofferdam structure 40, so that the cofferdam structure 40 can extend into the first grooves 16. This reduces the distance between the common electrode 22 and the pixel electrode 12 without reducing the height of the cofferdam structure 40, thereby avoiding the problem of excessive thickness causing the electronic paper 100 to fail to drive and improving the yield of the electronic paper 100.

[0030] In a specific embodiment, the boss layer 13 includes a connecting portion 131 and a plurality of protrusions 132. The connecting portion 131 is stacked on the first substrate 11, and the plurality of protrusions 132 are spaced apart from each other on the surface of the connecting portion 131 facing away from the first substrate 11. A first groove 16 is provided between any two adjacent protrusions 132, and a plurality of pixel electrodes 12 are stacked on the plurality of protrusions 132 in a one-to-one correspondence. Optionally, the connecting portion 131 and the plurality of protrusions 132 are an integral structure. The boss layer 13 can be integrally formed by coating and etching an insulating and light-shielding material such as polyimide or black matrix BM material on the first substrate 11, and there is no limitation.

[0031] In another implementation method, please refer to Figure 3 and Figure 4 The color filter substrate 20 has multiple second grooves 23. One end of the dam structure 40 is connected to the array substrate 10, and the other end extends into the multiple second grooves 23. Specifically, multiple protrusions 42 of the dam structure 40 are connected to the end of the main body 41 facing the color filter substrate 20 and are correspondingly arranged with the multiple second grooves 23 one by one, so that the multiple protrusions 42 can extend into the corresponding second grooves 23. This reduces the distance between the common electrode 22 and the pixel electrode 12 without reducing the height of the dam structure 40, thereby avoiding the problem of electronic paper 100 driving failure due to excessive cell thickness, improving the yield of electronic paper 100, and preventing damage to the driving circuit layer during the fabrication of the second grooves 23.

[0032] In a specific embodiment, the array substrate 10 further includes a back coating layer 14, which is stacked on the side of the first substrate 11 facing away from the second substrate 21. Since the color filter substrate 20 is used to receive ambient light and emit display light, the materials constituting the color filter substrate 20 are all materials with high light transmittance to reduce the impact on the color effect of the displayed image. Therefore, in order to increase the contrast of the electronic paper 100 display, a back coating layer 14 is also provided on the side of the first substrate 11 facing away from the second substrate 21. The back coating layer 14 can be made of a light-blocking material, specifically similar to the material of the aforementioned dam structure 40 or boss layer 13, which can be referred to for further details.

[0033] In a specific embodiment, the array substrate 10 further includes a planarization layer 15, which is disposed on the side of the plurality of pixel electrodes 12 facing away from the first substrate 11. The dam structure 40 is connected to the planarization layer 15. Since the pixel electrodes 12 and the driving circuit disposed on the first substrate 11 have uneven surfaces, when the dam structure 40 is directly connected to the pixel electrodes 12, the connection strength between the dam structure 40 and the array substrate 10 is low and separation is likely to occur, posing a risk of leakage and cross-contamination. Therefore, a planarization layer 15 is disposed on the surface of the pixel electrodes 12 facing away from the first substrate 11 to ensure a firm connection between the dam structure 40 and the array substrate 10, making separation less likely. Optionally, the planarization layer 15 can be made of inorganic materials such as silicon nitride, silicon oxide, or silicon oxynitride, without limitation.

[0034] In one embodiment, please refer to Figure 3 , Figure 3 The diagram shown is a cross-sectional view of the electronic paper 100 according to the second embodiment, with a second groove 23 between any two adjacent common electrodes 22. Specifically, each second groove 23 is surrounded by a plurality of common electrodes 22 stacked on the second substrate 21. When the protrusion 42 of the dam structure 40 extends into the second groove 23, the protrusion 42 is opposite to the outer peripheral surface of the common electrode 22, reducing the fabrication steps of the color filter substrate 20.

[0035] In another embodiment, please refer to Figure 4 , Figure 4The diagram shows a cross-sectional view of the electronic paper 100 according to the third embodiment. The color filter substrate 20 further includes multiple protrusions 132, which are disposed on the side of the second substrate 21 facing the array substrate 10. Multiple common electrodes 22 are stacked on the multiple protrusions 132 in a one-to-one correspondence. The multiple protrusions 132 are made of a light-transmitting material, such as OC photoresist or transparent polyimide, without limitation. Specifically, the second groove 23 is formed by the multiple protrusions 132 stacked on the second substrate 21. When the protrusion 42 of the dam structure 40 extends into the second groove 23, the protrusion 42 faces the outer peripheral surface of the protrusion 132 and also faces the outer peripheral surface of the common electrode 22, thereby reducing the material cost of the common electrode 22. In a specific embodiment, the multiple common electrodes 22 are connected to both the outer peripheral surface of the multiple protrusions 132 and the second substrate 21 in a one-to-one correspondence. Optionally, multiple common electrodes 22 may also be connected to multiple protrusions 132 on the surface facing the first substrate 11, without limitation.

[0036] In another implementation method, please refer to Figure 5 , Figure 5 The diagram shown is a cross-sectional view of the electronic paper 100 according to the fourth embodiment. The array substrate 10 has a plurality of first grooves 16 arranged in an array, and the color filter substrate 20 has a plurality of second grooves 23 arranged in an array. The main body 41 of the dam structure 40 has a plurality of protrusions 42 arranged in an array connected to both the end near the array substrate 10 and the end near the color filter substrate 20, and these protrusions extend into the corresponding grooves. The structure of the color filter substrate 20 is similar to... Figure 3 or Figure 4 The structure of the color filter substrate 20 of the electronic paper 100 shown is similar to that of the array substrate 10. Figure 2 The structure of the array substrate 10 of the electronic paper 100 shown is similar, except that the depth of the second groove 23 of the color filter substrate 20 in this embodiment is less than that of the array substrate 10. Figure 3 or Figure 4 The depth of the second groove 23 of the color filter substrate 20 of the electronic paper 100 shown is less than the depth of the first groove 16 of the array substrate 10 in this embodiment. Figure 2 The depth of the first groove 16 of the array substrate 10 of the electronic paper 100 is shown. By providing multiple grooves arranged in an array on both the array substrate 10 and the color filter substrate 20 for the dam structure 40 to extend into, the connection strength between the dam structure 40 and the array substrate 10 and the color filter substrate 20 is higher, which is also beneficial for precise control of the cell thickness of the electronic paper 100.

[0037] The electronic paper 100 provided by the present invention comprises an array substrate 10, a color filter substrate 20, a liquid crystal layer 30, and a dam structure 40. The color filter substrate 20 is disposed at a distance from the array substrate 10, the liquid crystal layer 30 is disposed between the array substrate 10 and the color filter substrate 20, and the dam structure 40 is disposed between the array substrate 10 and the color filter substrate 20 and passes through the liquid crystal layer 30. The array substrate 10 has a plurality of first grooves 16. One end of the dam structure 40 is connected to the color filter substrate 20, and the other end extends into the plurality of first grooves 16. And / or, the color filter substrate 20 has a plurality of second grooves 23. One end of the dam structure 40 is connected to the array substrate 10, and the other end extends into the plurality of second grooves 23. This reduces the distance between the array substrate 10 and the color filter substrate 20 without reducing the height of the dam structure 40, thereby avoiding the problem of electronic paper 100 driving failure due to excessive cell thickness and improving the yield of electronic paper 100.

[0038] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship of the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and other indicators are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0039] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An electronic paper, characterized by comprising: The array substrate comprises a first substrate, a plurality of pixel electrodes and a back paint layer, the first substrate is arranged opposite and spaced apart from the second substrate, the plurality of pixel electrodes are arranged opposite and spaced apart from each other on the side of the first substrate facing the second substrate, and the back paint layer is laminated on the side of the first substrate away from the second substrate. The array substrate further comprises a flat layer, the flat layer is arranged on the side of the plurality of pixel electrodes away from the first substrate, and the cofferdam structure is connected with the flat layer. The liquid crystal layer comprises a plurality of cholesteric liquid crystals arranged in the same layer and spaced apart from each other. The cofferdam structure comprises a main body and a plurality of protruding portions, one end or both ends of the main body are connected with the plurality of protruding portions, the main body is arranged between the array substrate and the color film substrate and penetrates the liquid crystal layer. The cofferdam structure comprises a main body and a plurality of protruding portions, one end or both ends of the main body are connected with the plurality of protruding portions, the main body is arranged between the array substrate and the color film substrate and penetrates the liquid crystal layer. ​ 2. The electronic paper of claim 1, wherein, ​ ​ 3. The electronic paper of claim 2, wherein, ​ 4. The electronic paper of claim 1, wherein, ​ ​ 5. The electronic paper of claim 4, wherein, ​ 6. The electronic paper of claim 5, wherein, ​ 7. The electronic paper of claim 4, wherein, ​ 8. The electronic paper of claim 7, wherein, ​ 9. The electronic paper of claim 1, wherein, ​ 10. The electronic paper according to any one of claims 1 to 9, characterized in that, ​

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