Electrowetting electronic paper display device

Abstract

An electrowetting electronic paper display device disclosed by the present invention comprises a first substrate, an electrode layer, a first reflective layer, a pixel layer and a second substrate which are sequentially arranged from bottom to top, the pixel layer comprises a pixel wall and charged ink, the pixel wall is divided into a plurality of pixel units arranged in an array, and the charged ink is arranged in each pixel unit; the charged ink in each pixel unit can be unfolded to cover the first reflective layer and can be contracted to one side of the pixel wall under the action of an electric field of the electrode layer; a second light reflecting layer is further arranged between the second substrate and the pixel layer, the second light reflecting layer comprises a plurality of light reflecting baffles arranged in an array mode, each light reflecting baffle is located on one side of the corresponding pixel unit, and the orthographic projection of the light reflecting baffle on the first light reflecting layer can shield the shrunk charged ink in the corresponding pixel unit. The electrowetting electronic paper display device not only can shield the shrunk charged ink, but also can avoid the problems of breakage or deformation and the like of the pixel wall, and the response speed of the charged ink is not influenced.

Description

Technical Field

[0001] This invention relates to electronic paper display technology, and more particularly to an electrowetting electronic paper display device. Background Technology

[0002] Electrowetting electronic paper is a novel reflective "paper-like" display technology based on the electrowetting effect. It achieves image display by controlling the contraction and expansion of charged ink within pixels through an electric field, and has the advantages of low power consumption and easy readability.

[0003] The charged ink in electrowetting electronic paper forms black dots in the lit pixels after shrinkage. To solve this problem, Chinese Patent Application No. CN202411225800.3 discloses an electrowetting electronic paper display device, which includes: Two opposing first substrates and second substrates are provided. The first substrate is provided with a plurality of pixel units arranged in an array, and a pixel wall is provided between two adjacent pixel units. An electrode layer is disposed on the surface of the first substrate facing the second substrate; A reflective layer is disposed on the surface of the electrode layer facing away from the first substrate; A liquid layer comprising a plurality of liquid units disposed between the reflective layer and the second substrate and located between two adjacent pixel walls. The liquid unit comprises charged ink, which expands to cover the surface of the reflective layer and contracts to the end of the pixel wall facing the reflective layer under the action of the electric field of the electrode layer. A reflective baffle is obliquely disposed on the pixel wall and extends toward the reflective layer to cover the shrinking charged ink, and there is a gap between the reflective baffle and the reflective layer to allow the charged ink to shrink or expand.

[0004] This patent uses a reflective baffle to shield the retracted charged ink, preventing black spots from forming in the illuminated pixels. However, the pixel wall is narrow and weak, making it prone to breakage or deformation when the reflective baffle is placed on it. Furthermore, the asymmetrical force distribution caused by the baffle being placed only on one side exacerbates the breakage or deformation problems. Additionally, the small gap between the reflective baffle and the reflective layer means the charged ink is still somewhat hindered during expansion and contraction, especially when the ink is thick, thus reducing its response speed. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention provides an electrowetting electronic paper display device that can both block the shrunken charged ink and prevent problems such as breakage or deformation of the pixel wall, without affecting the response speed of the charged ink.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solution: An electrowetting electronic paper display device includes, from bottom to top, a first substrate, an electrode layer, a first reflective layer, a pixel layer, and a second substrate. The pixel layer includes pixel walls and charged ink. The pixel walls separate multiple pixel units arranged in an array. The charged ink is disposed within each pixel unit. The charged ink in each pixel unit can expand to cover the first reflective layer and can contract to one side of the pixel wall under the action of the electric field of the electrode layer. A second reflective layer is also provided between the second substrate and the pixel layer. The second reflective layer includes multiple reflective baffles arranged in an array. Each reflective baffle is located on one side of the corresponding pixel unit, and its orthogonal projection on the first reflective layer can block the contracted charged ink in the corresponding pixel unit.

[0007] Furthermore, each reflective baffle is tilted relative to the second substrate to reflect external light into the corresponding pixel unit.

[0008] Furthermore, the angle between each reflective baffle and the second substrate on the side facing the corresponding pixel unit is an obtuse angle.

[0009] Furthermore, the angle between each reflective baffle and the second substrate on the side facing the corresponding pixel unit is between 130° and 150°.

[0010] Furthermore, a high-transmittance dielectric layer is provided between the second substrate and the second reflective layer. The high-transmittance dielectric layer has a groove structure at the position corresponding to each pixel unit. Each groove structure is inclined relative to the second substrate at least near the sidewall of the corresponding reflective baffle. Each reflective baffle is disposed on the inclined sidewall of the corresponding groove structure.

[0011] Furthermore, all sidewalls of each groove structure are inclined relative to the second substrate to form a trapezoidal groove that is narrower at the top and wider at the bottom.

[0012] Furthermore, each groove structure is located on the side of the corresponding pixel unit near the shrunken charged ink.

[0013] Furthermore, the pixel layer also includes a transparent liquid disposed within each pixel unit; the transparent liquid is immiscible with the charged ink, and the density of the transparent liquid is less than the density of the charged ink.

[0014] Furthermore, the electrowetting electronic paper display device also includes a first hydrophobic insulating layer, which is disposed between the first reflective layer and the pixel layer.

[0015] Furthermore, the electrowetting electronic paper display device also includes a second hydrophobic insulating layer, which is disposed between the second reflective layer and the pixel layer.

[0016] The present invention has the following beneficial effects: The electrowetting electronic paper display device of the present invention sets each reflective baffle used to shield the shrunken charged ink on the second substrate. Compared with the pixel wall, the second substrate has greater strength, which can provide better support for each reflective baffle and will not cause problems such as breakage or deformation under the force of each reflective baffle. At the same time, since each reflective baffle is located above the corresponding pixel unit, rather than inside it, even if the thickness of the charged ink is large, each reflective baffle will not hinder the unfolding and shrinking of the charged ink, thus ensuring the response speed of the charged ink. Attached Figure Description

[0017] Figure 1 This is a cross-sectional structural schematic diagram of the electrowetting electronic paper display device provided by the present invention.

[0018] Figure 2 This is a cross-sectional structural schematic diagram of another electrowetting electronic paper display device provided by the present invention.

[0019] Figure 3 This is a cross-sectional structural schematic diagram of another electrowetting electronic paper display device provided by the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] Example 1 like Figure 1 As shown, an electrowetting electronic paper display device includes, from bottom to top, a first substrate 1, an electrode layer 2, a first reflective layer 3, a pixel layer 5, and a second substrate 8. The pixel layer 5 includes a pixel wall 51 and charged ink 52. The pixel wall 51 separates a plurality of pixel units 50 arranged in an array. The charged ink 52 is disposed in each pixel unit 50. The charged ink 52 in each pixel unit 50 can unfold to cover the first reflective layer 3 and can shrink to one side of the pixel wall 51 under the action of the electric field of the electrode layer 2. A second reflective layer 7 is also provided between the second substrate 8 and the pixel layer 5. The second reflective layer 7 includes a plurality of reflective baffles 71 arranged in an array. Each reflective baffle 71 is located on one side of the corresponding pixel unit 50, and its orthogonal projection on the first reflective layer 3 can block the shrunken charged ink 52 in the corresponding pixel unit 50.

[0025] The electrowetting electronic paper display device of the present invention has reflective baffles 71 for shielding the shrunken charged ink 52 disposed on the second substrate 8. Compared with the pixel wall 51, the second substrate 8 has greater strength, which can provide better support for each reflective baffle 71 and will not break or deform under the force of each reflective baffle 71. At the same time, since each reflective baffle 71 is located above the corresponding pixel unit 50, rather than inside it, even if the thickness of the charged ink 52 is large, each reflective baffle 71 will not hinder the unfolding and shrinking of the charged ink 52, thus ensuring the response speed of the charged ink 52.

[0026] When a pixel unit 50 is in a dark state, the electrode layer 2 does not generate any electric field within the pixel unit 50. The charged ink 52 within the pixel unit 50 can spread out under the action of its own surface energy and tension to cover the first reflective layer 3. When a pixel unit 50 is in a bright state, the electrode layer 2 generates a driving electric field within the pixel unit 50. The charged ink 52 within the pixel unit 50 can contract to one side of the pixel wall 51 under the action of the driving electric field. The contracted charged ink 52 can be blocked by the corresponding reflective baffle 71 above it. The reflective baffle 71 and the first reflective layer 3 jointly reflect external light, so no black spots are formed within the pixel unit 50.

[0027] Specifically, the first substrate 1 and the second substrate 8 are arranged parallel to each other. Both can be rigid substrates such as glass substrates, ceramic substrates, sapphire substrates, or acrylic substrates, or flexible films such as polyimide films, polyester films, cyclic olefin polymer films, or polycarbonate films. Even if the second substrate 8 uses a flexible film, it has high toughness, and it is bonded and fixed to the first substrate 1 on the periphery of the pixel layer 5 with adhesive to maintain a certain tension. In the middle area, it is supported by the pixel wall 51 to prevent deformation towards the first substrate 1. Therefore, it will not have problems such as breakage or deformation due to the setting of various reflective baffles 71.

[0028] The second reflective layer 7 may be, but is not limited to, a metal film layer, which is attached to the surface of the second substrate 8 by means of magnetron sputtering, vacuum evaporation or chemical vapor deposition, and then forms various reflective baffles 71 by means of mask etching or laser etching.

[0029] The first reflective layer 3 and the second reflective layer 7 may, but are not limited to, use a single metal film, an alloy metal film, or a metal oxide film containing metal elements such as gold, silver, aluminum, copper, and titanium.

[0030] In this embodiment, the charged ink 52 is a black ink, and its components include carbon black, a conductive agent, and a thickener. The carbon black can be selected from metal powder or graphite, the conductive agent can be selected from polyolefin or carbon fiber, and the thickener can be selected from organic expanding agents or natural gum. The use of black ink for the charged ink allows the pixel unit 50 to be displayed in a black and white state; that is, when the electrode layer 2 does not generate any electric field, the pixel unit 50 displays black, and when the electrode layer 2 generates a driving electric field, the pixel unit 50 displays white.

[0031] Of course, in some other embodiments, the charged ink 52 may also be a charged colored ink, so that the pixel unit 50 displays color.

[0032] The pixel layer 5 further includes a transparent liquid 53, which is disposed in each pixel unit 50; the transparent liquid 53 is immiscible with the charged ink 52, and the density of the transparent liquid 53 is less than the density of the charged ink 52.

[0033] The transparent liquid 53 serves to deposit the charged ink 52 at the bottom of the pixel unit 50 (i.e., near the first reflective layer 3) due to its low density, while also utilizing gravity to accelerate the spread of the charged ink 52. The transparent liquid 53 may be, but is not limited to, water, anhydrous glycerol, haloalkanes, or organic transparent liquid polymers.

[0034] The electrowetting electronic paper display device further includes a first hydrophobic insulating layer 4 and a second hydrophobic insulating layer 6. The first hydrophobic insulating layer 4 is disposed between the first reflective layer 3 and the pixel layer 5, and the second hydrophobic insulating layer 6 is disposed between the second reflective layer 7 and the pixel layer 5.

[0035] The main functions of the first hydrophobic insulating layer 4 and the second hydrophobic insulating layer 6 are to reduce the adhesion between the charged ink 52 and the transparent liquid 53 and the first reflective layer 3 and the second reflective layer 7, improve the response speed of the expansion and contraction of the charged ink 52, and provide a certain degree of electrical isolation.

[0036] The first hydrophobic insulating layer 4 and the second hydrophobic insulating layer 6 may be, but are not limited to, made of fluoropolymer materials such as polytetrafluoroethylene, perfluoropolyether or fluorinated acrylate, or polysiloxane materials such as polydimethylsiloxane or fluorinated polysiloxane, or hydrophobically modified inorganic non-metallic oxides or inorganic non-metallic nitrides.

[0037] Example 2 As an optimization of Embodiment 1, in this embodiment, such as Figure 2 As shown, each reflective baffle 71 is tilted relative to the second substrate 8 to reflect external light into the corresponding pixel unit 50, thereby increasing the display brightness of each pixel unit 50.

[0038] More preferably, the angle α between each reflector 71 and the second substrate 8 on the side facing the corresponding pixel unit 50 is an obtuse angle, so as to reflect external light with a larger incident angle into the corresponding pixel unit 50.

[0039] The pixel wall 51 is typically made of black photoresist material, which has light-absorbing properties. External light reflected by the reflective baffle 71 onto the pixel wall 51 is absorbed by the pixel wall 51, thus reducing light utilization.

[0040] Therefore, optimally, the angle α between each reflective baffle 71 and the second substrate 8 on the side facing the corresponding pixel unit 50 is between 130° and 150°, so as to reflect as much external light as possible onto the first reflective layer 3 inside the corresponding pixel unit 50, and then the first reflective layer 3 reflects the external light to the outside of the corresponding pixel unit 50, thereby reducing the absorption of external light by the pixel wall 51 and improving the light utilization rate.

[0041] A high-transmittance dielectric layer 9 is also provided between the second substrate 8 and the second reflective layer 7. The high-transmittance dielectric layer 9 has a groove structure 91 at the position corresponding to each pixel unit 50. Each groove structure 91 is inclined relative to the second substrate 8 at least close to the side wall of the corresponding reflective baffle 71. Each reflective baffle 71 is disposed on the inclined side wall of the corresponding groove structure 91.

[0042] The high-transparency dielectric layer 9 serves to provide the necessary attachment surface for the inclined setting of each reflective baffle 71 using the inclined sidewalls of its groove structure 91. During fabrication, a high-transparency dielectric material (such as inorganic non-metallic oxides or organic polymers) is first attached to the surface of the second substrate 8 using methods such as magnetron sputtering, vacuum evaporation, chemical vapor deposition, roll coating, or spraying to form the high-transparency dielectric layer 9. Then, the high-transparency dielectric layer 9 is etched using methods such as mask etching or laser etching to form each groove structure 91. Next, a metal material is attached to the surface of the high-transparency dielectric layer 9 using methods such as magnetron sputtering, vacuum evaporation, or chemical vapor deposition to form the second reflective layer. Finally, the second reflective layer is etched using methods such as mask etching or laser etching to form each reflective baffle 71.

[0043] The high-transparency dielectric layer 9 may be, but is not limited to, inorganic non-metallic oxides such as silicon oxide, silicon nitride, or silicon oxynitride, or organic polymers such as silicone, polyurethane resin, or epoxy resin.

[0044] Preferably, all sidewalls of each groove structure 91 are inclined relative to the second substrate 8 to form a trapezoidal groove that is narrow at the top and wide at the bottom.

[0045] The transparent liquid 53 filled in the trapezoidal groove acts as a focusing lens. When external light enters the transparent liquid 53 through the side wall edge of the trapezoidal groove, it is refracted, thereby forming a focusing effect to improve pixel brightness.

[0046] Preferred, such as Figure 3 As shown, each groove structure 91 is located on the side of the corresponding pixel unit 50 near the shrunken charged ink 52 to compensate for the brightness of the corresponding pixel unit 50 on the side near the shrunken charged ink 52, so that the brightness of each pixel unit 50 is more uniform.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrowetting electronic paper display device, comprising, from bottom to top, a first substrate, an electrode layer, a first reflective layer, a pixel layer, and a second substrate, wherein the pixel layer includes pixel walls and charged ink, the pixel walls separating a plurality of pixel units arranged in an array, and the charged ink being disposed within each pixel unit; the charged ink within each pixel unit can expand to cover the first reflective layer, and can contract to one side of the pixel wall under the action of the electric field of the electrode layer; characterized in that, A second reflective layer is provided between the second substrate and the pixel layer. The second reflective layer includes multiple reflective baffles arranged in an array. Each reflective baffle is located on one side of the corresponding pixel unit, and its orthogonal projection on the first reflective layer can block the charged ink that has shrunk in the corresponding pixel unit.

2. The electrowetting electronic paper display device according to claim 1, characterized in that, Each reflector is tilted relative to the second substrate to reflect external light into the corresponding pixel unit.

3. The electrowetting electronic paper display device according to claim 2, characterized in that, The angle between each reflective baffle and the second substrate on the side facing the corresponding pixel unit is an obtuse angle.

4. The electrowetting electronic paper display device according to claim 3, characterized in that, The angle between each reflector and the second substrate on the side facing the corresponding pixel unit is between 130° and 150°.

5. The electrowetting electronic paper display device according to any one of claims 2-4, characterized in that, A high-transmittance dielectric layer is also provided between the second substrate and the second reflective layer. The high-transmittance dielectric layer has a groove structure at the position corresponding to each pixel unit. Each groove structure is inclined relative to the second substrate at least near the side wall of the corresponding reflective baffle. Each reflective baffle is disposed on the inclined side wall of the corresponding groove structure.

6. The electrowetting electronic paper display device according to claim 5, characterized in that, All sidewalls of each groove structure are inclined relative to the second substrate to form a trapezoidal groove that is narrower at the top and wider at the bottom.

7. The electrowetting electronic paper display device according to claim 6, characterized in that, Each groove structure is located on the side of the corresponding pixel unit closest to the shrunken charged ink.

8. The electrowetting electronic paper display device according to claim 1, characterized in that, The pixel layer also includes a transparent liquid disposed within each pixel unit; the transparent liquid is immiscible with the charged ink, and the density of the transparent liquid is less than the density of the charged ink.

9. The electrowetting electronic paper display device according to claim 1, characterized in that, The electrowetting electronic paper display device further includes a first hydrophobic insulating layer, which is disposed between the first reflective layer and the pixel layer.

10. The electrowetting electronic paper display device according to claim 1 or 9, characterized in that, The electrowetting electronic paper display device further includes a second hydrophobic insulating layer, which is disposed between the second reflective layer and the pixel layer.

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