Electrowetting display device and preparation method and application thereof

Abstract

The invention discloses an electrowetting display device and a preparation method and application thereof.The electrowetting display device comprises a reflection type supporting assembly, an electrowetting display layer and a transmission type supporting assembly which are arranged in a stacked mode from bottom to top, and the reflection type supporting assembly comprises a first substrate and a diffuse reflection layer from bottom to top; the diffuse reflection layer comprises a light imprint relief microstructure layer arranged on the lower layer and a mirror reflection layer arranged on the upper layer, and the light imprint relief microstructure layer is a fluctuating micron-sized microstructure layer prepared according to a light imprint technology. According to the invention, a layer of micron-sized fluctuating microstructure is prepared on the upper surface of the driving back plate of the electrowetting display device and below a specular reflection coating in a pixel by adopting a light imprinting method to form a diffuse reflection layer, and more ambient light can be reflected into human eyes through the diffuse reflection layer by utilizing diffuse reflection of the microstructure to incident light; due to diffuse reflection of the particles, reflected light with a larger reflection angle is generated for ambient light, so that the visual angle of the electrowetting display device is widened, and the display effect of the device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrowetting display, and in particular to an electrowetting display device and a preparation method and application thereof. Background Art

[0002] With the continuous development of information technology, electrowetting display technology has made great progress. In order to achieve the purpose of reflective display, in-depth research has been carried out both at home and abroad. At present, the display of reflective display devices mainly adds a scattering film layer that can reflect ambient light to the electronic paper, and achieves a visible effect by reflecting ambient light. At present, a metal reflective layer is usually used, but its mirror reflection is significant and the viewing angle is small, resulting in poor display effect of the display device. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an electrowetting display device having the characteristics of wide viewing angle and good device display effect.

[0004] The invention also provides a method for preparing the electrowetting display device.

[0005] The present invention also proposes the application of the electrowetting display device.

[0006] In the first aspect of the present invention, an electrowetting display device is proposed, comprising a reflective support component, an electrowetting display layer and a transmissive support component stacked from bottom to top, the reflective support component comprising a first substrate and a diffuse reflection layer from bottom to top, the diffuse reflection layer comprising a photoembossed embossed microstructure layer arranged in the lower layer and a mirror reflection layer arranged in the upper layer, the photoembossed embossed microstructure layer is an undulating micrometer-level microstructure layer prepared according to the photoembossing technology.

[0007] The electrowetting display device according to the embodiment of the present invention has at least the following beneficial effects: The electrowetting display device in the present invention is a diffuse reflection electrowetting display device with a wider viewing angle, wherein the addition of the photoembossed embossed microstructure layer utilizes the diffuse reflection of the incident light by the photoembossed embossed microstructure layer so that more ambient light can be reflected into the human eye through the diffuse reflection layer. Since the diffuse reflection of particles produces reflected light with a larger reflection angle on the ambient light, the viewing angle of the diffuse reflection layer device is widened, so as to achieve the widening of the viewing angle of the electrowetting display device and improve the display effect of the device, thereby solving the problem of poor display effect of the existing reflective electrowetting display device, being able to effectively improve the diffuse reflectivity, widen the viewing angle, and have a better display effect when watching. The device can be suitable for outdoor high-brightness environments, is green and environmentally friendly, and protects the eyes, and has good application prospects.

[0008] In some embodiments of the present invention, the first substrate comprises a first light-transmitting substrate. Optionally, the material of the first light-transmitting substrate may be glass. Optionally, the thickness of the first substrate comprises 0.5-0.8 mm.

[0009] In some embodiments of the present invention, the photoembossed embossed microstructure layer is an irregularly undulating microstructure layer. Optionally, the thickness of the photoembossed embossed microstructure layer includes 0.1-3 μm, and further optionally 0.5-2 μm. In order to ensure the paper-like effect of electronic paper, the photoembossed embossed microstructure layer of the electrowetting display device in the present invention is relatively small, and the thickness can be several microns.

[0010] In some embodiments of the present invention, the reflective support assembly further includes a first electrode disposed between the first substrate and the diffuse reflection layer, and a hydrophobic insulating layer disposed between the diffuse reflection layer and the electrowetting display layer.

[0011] In some embodiments of the present invention, the first electrode is a transparent material. Optionally, the first electrode includes but is not limited to a metal electrode or indium tin oxide (ITO). Further, the thickness of the first electrode includes 20-30 nm.

[0012] In some embodiments of the present invention, the thickness of the hydrophobic insulating layer is comprised between 0.4 and 1 μm.

[0013] In some embodiments of the present invention, the electrowetting display layer includes a sealed cavity and a pixel wall. The sealed cavity is located between the reflective support component and the transmissive support component and is formed by encapsulation of a packaging material. The pixel wall is arranged on the surface of the hydrophobic insulating layer. The sealed cavity is filled with a first fluid and a second fluid that are immiscible with each other. The pixel walls enclose pixel units arranged in an array, and the first fluid is filled in the pixel units.

[0014] In some embodiments of the present invention, the distance between the reflective support component and the transmissive support component is 50-190 μm, and can be further optionally 54.45-183.85 μm.

[0015] In some embodiments of the present invention, the packaging material includes but is not limited to pressure sensitive adhesive.

[0016] In some embodiments of the present invention, one of the first fluid and the second fluid is a polar fluid and the other is a non-polar fluid. Specifically, the first fluid is a non-polar fluid and the second fluid is a polar fluid. Optionally, the non-polar fluids can be ink or other non-polar fluids, and the polar fluid can be water or a polar fluid containing alcohols.

[0017] In some embodiments of the present invention, two immiscible fluids are filled in the electrowetting display layer by inkjet printing, and the contraction and expansion of the non-polar fluid such as ink are controlled by an applied voltage to control the display of the electrowetting device. Optionally, the first fluid and the second fluid are ink and water, respectively, and the voltage is regulated to cause the ink to contract and expand, thereby controlling the display of the electrowetting device. Through the above embodiments, under the condition of an applied voltage, the first fluid can move or deform within the pixel unit, specifically, in a spread state or a contracted state within the pixel unit.

[0018] In some embodiments of the present invention, the transmissive support assembly includes a second electrode and a second substrate stacked along the direction of the electrowetting display layer.

[0019] In some embodiments of the present invention, the second electrode is a transparent material. Optionally, the second electrode includes but is not limited to a metal electrode or ITO. Further, the thickness of the second electrode includes 20-30 nm.

[0020] In some embodiments of the present invention, the second substrate comprises a second light-transmitting substrate. Optionally, the second light-transmitting substrate may be made of glass. Further, the thickness of the second substrate comprises 0.5-0.8 mm.

[0021] In some embodiments of the present invention, the electrowetting display device further includes a power control module. Optionally, the device is externally provided with the power control module. The power control module is used to control the voltage between the reflective support component and the transmissive support component. Specifically, such as the voltage between the first electrode and the second electrode. Specifically, the voltage generated by the power control module causes the fluid (such as ink) in the pixel unit to shrink, the display layer exposes the light-transmitting area, and the ambient light passes through the light-transmitting area of ​​the display layer to reach the photo-embossed embossed microstructure layer, and the diffuse reflection of the ambient light by the microstructure diffuse reflection structure (such as the photo-embossed embossed structure) achieves the effect of widening the display viewing angle.

[0022] The second aspect of the present invention also provides a method for preparing an electrowetting display device, including preparing a photoembossed embossed microstructure layer, which specifically includes the following steps: (1) firstly spin-coating a photopolymer onto a substrate surface to obtain a photopolymer film; (2) then drying the photopolymer film to remove the solvent; (3) then exposing the photopolymer film to a mask to produce a latent image; (4) finally heating the sample for development, and obtaining a photoembossed embossed microstructure layer after the entire film is exposed and cured.

[0023] In some embodiments of the present invention, the substrate may be the first electrode. Further, the substrate includes a first substrate and a first electrode stacked together, and the silicon dioxide dispersion is coated on the surface of the first electrode.

[0024] In some embodiments of the present invention, the photopolymer includes a polymeric binder, a monomer, a retarder and a photoinitiator. Optionally, the polymeric binder includes polymethyl methacrylate; the monomer includes acrylate; the retarder includes tert-butylhydroquinone; and the photoinitiator includes Irgacure 819. Specifically, in the photopolymer, the mass fraction of the polymeric binder includes 10-40%, and further optionally 20%-30%; the mass fraction of the monomer includes 10-30%, and further optionally 20%-30%; the mass fraction of the retarder includes 0.1-20%, and further optionally 1%-10%; the mass fraction of the photoinitiator includes 0.1-20%, and further optionally 1%-10%; the mass fraction of the solvent includes 30-60%, and further optionally 40%-50%.

[0025] In some embodiments of the present invention, the photopolymer comprises polymethyl methacrylate and multifunctional acrylate in a ratio of 1:1. Optionally, the acrylate comprises dipentaerythritol penta / hexaacrylate.

[0026] In addition, the solvent in the photopolymer includes a mixture of ethoxypropyl acetate and propylene glycol-methyl ethyl acetate in a ratio of 1:1. Specifically, the volume ratio of polymethyl methacrylate, dipentaerythritol penta / hexaacrylate, tert-butylhydroquinone, Irgacure 819, ethoxypropyl acetate and propylene glycol-methyl ethyl acetate is selected from (20-30): (20-30): (1-10): (1-10): (40-50).

[0027] In some embodiments of the present invention, the preparation step of the photopolymer includes: taking materials used for the photopolymer, mixing, heating and stirring to obtain the photopolymer. Optionally, the heating and stirring temperature is selected from 40-60°C, and the heating and stirring time is selected from 5-30 minutes.

[0028] In some embodiments of the present invention, in step (1), the spin coating speed includes 2000-3000 revolutions per minute, and the spin coating time includes 10-180 seconds; In some embodiments of the present invention, in step (2), the drying temperature is 20-80° C., and the drying time is 10-180 min; In some embodiments of the present invention, in step (3), the exposure light intensity is 10-20 mW / cm2, the exposure time is 10-30 s, and the size of the photolithography mask is 1 x 1 cm. Specifically, the photolithography mask comprises a hexagonal filler consisting of 30 μm transparent holes, and the spacing between these holes is 30 μm.

[0029] In some embodiments of the present invention, in step (4), the heating temperature is 40-100° C., the heating time is 1-10 min. In addition, the exposure light intensity is selected from 10-20 mW / cm 2 , and the exposure time is 10-30 s.

[0030] In some embodiments of the present invention, the method for preparing the electrowetting display device includes the following steps: S1, preparing a photoembossed embossed microstructure layer on the surface of a first electrode to obtain a reflective support component; S2, preparing a pixel wall on the surface of the reflective support component; filling the pixel wall with a first fluid using an inkjet printing process; and assembling with a transmissive support component to obtain the electrowetting display device.

[0031] In some embodiments of the present invention, in step S1, a photoembossed embossed microstructure layer and a hydrophobic insulating layer are sequentially prepared on the surface of the first electrode to obtain a reflective support assembly.

[0032] In some embodiments of the present invention, in step S2, the reflective support assembly includes a hydrophobic insulating layer, and the pixel wall is prepared on the surface of the hydrophobic insulating layer. Optionally, a photoresist is spin-coated on the surface of the hydrophobic insulating layer, and the photoresist is exposed and developed through a mask to obtain the pixel wall.

[0033] In some embodiments of the present invention, in step S2, the reflective support component and the transmissive support component may be packaged using packaging materials according to phase change bonding technology.

[0034] The third aspect of the present invention proposes the application of the above-mentioned electrowetting display device in the field of electrowetting display, LED or LCD display technology.

[0035] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 Schematic diagram of the structure of the electrowetting display device in Example 1 of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the electrowetting display device in Example 1 of the present invention when no voltage is applied; Figure 3Schematic diagram of partial light reflection of the reflective layer of the electrowetting display device in Comparative Example 1; Figure 4 Schematic diagram of partial light reflection of the photoembossed relief microstructure layer in the electrowetting display device in Example 1 of the present invention; Figure 5 This is a schematic diagram of light reflection of the electrowetting display device in Example 1 of the present invention; Figure 6 This is a diagram showing the light reflection effect of the electrowetting display device in Comparative Example 3; Figure 7 This is a diagram showing the light reflection effect of the electrowetting display device in Example 1 of the present invention; Figure 8 This is a diagram of the light reflection effect of the electrowetting display device in Comparative Example 2.

[0038] Figure numerals: reflective support component 1, first substrate 11, first electrode 12, photo-embossed embossed microstructure layer 21, mirror reflection layer 22, hydrophobic insulating layer 3, first liquid 4, second liquid 5, electrowetting display layer 6, pixel wall 7, pixel unit cell 71, transmissive support component 8, second electrode 81, second substrate 82, power control module 9, first light-transmitting conductive substrate 10. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0042] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0043] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0044] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0045] The experimental methods in the following examples without specifying specific conditions are generally carried out according to conventional conditions in the art or conditions recommended by the manufacturers; the raw materials and reagents used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets.

[0046] Example 1 This embodiment discloses an electrowetting display device, the structural schematic diagram of which is shown in FIG. Figure 1-Figure 2 As shown, it includes a reflective support component 1, an electrowetting display layer 6 and a transmissive support component 8 stacked in sequence from bottom to top, the reflective support component 1 includes a first substrate 11, a first electrode 12, a light embossed embossed microstructure layer 2 and a hydrophobic insulating layer 3 stacked in sequence from small to top, and the transmissive support component 8 includes a second substrate 82 and a second electrode 81 stacked in sequence along the direction toward the reflective support component 1, wherein the first substrate 11 and the second substrate 82 are light-transmitting plates, the first electrode 12 and the second electrode 81 are both ITO, and the hydrophobic insulating layer 3 is preferably a super-hydrophobic insulating layer. The embossed embossed microstructure layer 2 includes a microstructure layer containing irregular undulations.

[0047] The electrowetting display layer 6 includes a sealed cavity and a pixel wall 7 disposed on the surface of the hydrophobic insulating layer. The pixel wall 7 encloses a pixel unit cell 71 (hereinafter referred to as a pixel unit cell). Figure 1), and the pixel cells 71 are arranged in an array, and each pixel cell 71 constitutes a pixel unit. The reflective support component 1 and the transmissive support component 8 are encapsulated by an encapsulation material to form a sealed cavity, and the sealed cavity is filled with a first fluid 4 (non-polar liquid, ink) and a second fluid 5 (polar liquid, water) that are immiscible with each other; the first fluid 4 is filled in each pixel cell 71. Optionally, the first substrate 11 and the second substrate 82 are both glass substrates with a thickness of 0.7 mm, the first electrode 12 and the second electrode 81 are both ITO layers with a thickness of about 25 nm, the hydrophobic insulating layer 3 is about 600 nm thick, the photoembossed embossed microstructure layer 1 is about 1.5 μm thick, and the pixel wall 7 is about 5 μm thick and made of epoxy resin photoresist. The first substrate 11 and the first electrode 12 can constitute a first light-transmitting conductive substrate 10, and the second substrate 82 and the second electrode 81 can constitute a second light-transmitting conductive substrate. Optionally, the distance between the reflective support component 1 and the transmissive support component 8 is selected from 54.45-183.85 μm.

[0048] The electrowetting display device also includes a power control module 9, which is used to control the voltage between the reflective support component 1 and the transmissive support component 8. After the electrowetting display device is voltaged, the electrode layer and the polar liquid cause the non-polar liquid to displace and deform, thereby controlling the device display switch, so that the ambient light reflection is observed by the human eye. Specifically: according to the electrowetting principle, when the voltage applied by the power control module 9 is greater than the threshold voltage of the movement of the first fluid 4, the first fluid 4 in the pixel unit is deformed, and the initial flat state is changed to a contracted state. At this time, the external environment incident light can be transmitted through the light-transmitting area of ​​the electrowetting display layer 6 to the photoembossed embossed microstructure layer 2. Due to the special structure of the photoembossed embossed microstructure layer 2, the ambient light can be reflected as a reflective light source with a larger reflection angle; if the applied voltage is less than the threshold voltage, the first fluid 4 is in a flat state in the pixel unit. At this time, the ambient incident light is completely absorbed by the first fluid 4 and cannot be reflected through the electrowetting display layer 6 to reflect the light source.

[0049] The method for preparing the electrowetting display device in this embodiment specifically includes the following steps: (I) Preparation of photoembossing relief template by spin coating: The photopolymer mixture is deposited as a photoembossing relief template by spin coating (the spin coating thickness is 1.5 μm, and the thickness can be 0.5-2 μm), specifically comprising: taking ITO glass (including a glass substrate and an ITO layer arranged on the surface of the glass substrate), spin coating the photopolymer solution on the surface of the ITO layer, setting the initial speed of the spin coater to 3000 rpm, accelerating the spin coating at an acceleration of 1500 rpm, and the spin coating time is 60 seconds.

[0050] (II) Drying the solvent: After the spin coating is completed, a photopolymer coating is formed on the surface of the ITO glass. The drying temperature is set to 80°C and the drying time is set to 10-20 minutes to remove the residual solvent and form a photoembossing relief template (abbreviated as: photoembossing template, the template contains a photopolymer).

[0051] (III) Photolithography mask exposure: Place the sample under a light intensity of 10-20 mW / cm 2 The photolithography mask is 1 × 1 cm in size and contains a hexagonal close-packed pattern of 30 μm transparent holes with a spacing of 30 μm between the holes.

[0052] (IV) Template heating: After the photolithography mask is exposed to form a relief image, the sample is placed in an air oven for baking. The baking temperature is set to 110°C and the baking time is 1-10 minutes. Finally, the sample is placed in a light intensity of 10-20 mW / cm 2 The whole piece is exposed under a certain temperature to cure the obtained microstructure diffuse reflection layer.

[0053] (V) Device packaging, including: continuing to spin-coat a hydrophobic insulating layer 3 on the microstructure diffuse reflection layer, spin-coating a photoresist and developing it to obtain a pixel wall 7, filling mutually immiscible ink and water into the electrowetting display layer 6 respectively, assembling it with a transmissive support component 8, and packaging it with a packaging material, thereby finally preparing an electrowetting display device.

[0054] Comparative Example 1 This comparative example discloses an electrowetting display device, which differs from Example 1 in that a conventional reflective layer with the same thickness is used in this comparative example to replace the photoembossed embossed microstructure layer 2 in Example 1. The conventional reflective layer is a metal reflective film (aluminum layer).

[0055] Comparative Example 2 This comparative example discloses an electrowetting display device, which is different from Example 1 in that: in this comparative example, the photoembossed relief microstructure layer 2 is located on the side of the first substrate 11 away from the first electrode 12 .

[0056] Comparative Example 3 This comparative example discloses an electrowetting display device, which is different from Example 1 in that: this comparative example does not contain a photoembossed embossed microstructure layer 2 .

[0057] Test example This test example compares and tests the performance of the electrowetting display devices in the embodiment and the comparative example, specifically including: (1) Comparative Example 1 The conventional reflective layer used in the electrowetting display device has a light reflection schematic diagram as shown in FIG. Figure 3As shown, the electrowetting display device in Example 1 adopts a photoembossed embossed microstructure layer 2, and its light reflection schematic diagram is shown in FIG. Figure 4-5 As shown; and the reflection effect diagrams of the electrowetting display devices of Comparative Example 3 and Example 1 on light are respectively as shown Figure 6-7 It can be seen that since the light embossed embossed microstructure layer 2 generates reflected light with a larger reflection angle for ambient light, the viewing angle of the diffuse reflection layer device is widened, which can solve the problem of small viewing angle and poor display effect of existing electrowetting display devices.

[0058] (2) Schematic diagram of light reflection of the electrowetting display device of comparative example 2 is shown in Figure 8 As shown, compared with comparative example 2 in which the photoembossed embossed microstructure layer 2 is located on the side of the first substrate 11 away from the first electrode 12, in example 1, the photoembossed embossed microstructure layer 2 is located between the first electrode 12 and the hydrophobic insulating layer 3, so that the incident light path becomes smaller, the light loss becomes smaller, the outgoing light is more, and a better reflection effect is achieved.

[0059] (3) Compared with the electrowetting display device in comparative example 1, the diffuse reflectivity of the electrowetting display device in embodiment 1 is increased by 20% to 30%; compared with the electrowetting display device in comparative example 2, the diffuse reflectivity of the electrowetting display device in embodiment 1 is increased by 10% to 20%; compared with the electrowetting display device in comparative example 3, the diffuse reflectivity of the electrowetting display device in embodiment 1 is increased by 35% to 50%.

[0060] In summary, the electrowetting display device of the present invention increases the setting of the photoembossed embossed microstructure layer 2, and utilizes the diffuse reflection of the incident light by the photoembossed embossed microstructure layer 2, so that more ambient light can pass through the photoembossed embossed microstructure layer 2 to the human eye. Since the diffuse reflection of particles produces reflected light with a larger reflection angle for ambient light, the viewing angle of the electrowetting display device is widened, so as to achieve the widening of the viewing angle of the electrowetting display device and improve the display effect of the device, thereby solving the problem of poor display effect caused by the small viewing angle of conventional reflective electrowetting display devices. Therefore, the electrowetting display device can also be used in outdoor high-brightness environments, is green and environmentally friendly, and protects the eyes, and has good application prospects.

[0061] It should be noted that the word “about” used in this document refers to an error of ±5%.

[0062] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An electrowetting display device, characterized in that: Including stacking from bottom to top: A reflective support assembly comprises a first substrate and a diffuse reflection layer from bottom to top, wherein the diffuse reflection layer comprises a photoembossed embossed microstructure layer arranged at a lower layer and a specular reflection layer arranged at an upper layer, wherein the photoembossed embossed microstructure layer is an undulating micron-scale microstructure layer prepared according to a photoembossing technique; Electrowetting display layer; Transmissive support assembly.

2. An electrowetting display device according to claim 1, characterized in that: The reflective support assembly further includes a first electrode disposed between the first substrate and the diffuse reflection layer, and a hydrophobic insulating layer disposed between the diffuse reflection layer and the electrowetting display layer.

3. An electrowetting display device according to claim 2, characterized in that: The electrowetting display layer includes a sealed cavity and a pixel wall. The sealed cavity is located between the reflective support component and the transmissive support component and is formed by encapsulation of an encapsulation material. The pixel wall is arranged on the surface of the hydrophobic insulating layer. The sealed cavity is filled with a first fluid and a second fluid that are immiscible with each other. The pixel walls are surrounded to form pixel units arranged in an array, and the first fluid is filled in the pixel units.

4. The electrowetting display device according to claim 1, characterized in that: The transmissive support assembly includes a second electrode and a second substrate stacked along the direction of the electrowetting display layer.

5. The electrowetting display device according to claim 1, characterized in that: The electrowetting display device also includes a power supply control module.

6. The electrowetting display device according to claim 1, characterized in that: The thickness of the photoembossing relief microstructure layer is 0.1-3 μm.

7. An electrowetting display device according to claim 6, characterized in that: The photoembossed embossed microstructure layer includes a photopolymer composed of a polymeric binder, a monomer, a retarder and a photoinitiator. The polymeric binder is polymethyl methacrylate, the monomer is acrylate, the retarder is tert-butylhydroquinone, and the photoinitiator is Irgacure819.

8. A method for preparing an electrowetting display device, characterized in that: The method comprises preparing the photoembossed embossed microstructure layer according to any one of claims 1 to 7, specifically comprising the following steps: (S100) spin coating the photopolymer on the surface of the substrate to obtain a photopolymer film; (S200) drying the photopolymer film to remove the solvent; (S300) exposing the photopolymer film through a mask to produce a latent image; (S400) The sample is heated for development, and the entire piece is exposed and cured to obtain a photoembossed relief microstructure layer.

9. The method for preparing an electrowetting display device according to claim 8, characterized in that: In step (S100), the spin coating speed includes 2000-3000 revolutions per minute, and the spin coating time includes 10-180 seconds; In step (S200), the drying temperature includes 20-80°C, and the drying time includes 10-180 minutes; In step (S300), the exposure light intensity includes 10-20 mW / cm2, and the exposure time includes 10-30 s; In step (S400), the heating temperature is 40-100°C, and the heating time is 1-10 minutes.

10. Application of the electrowetting display device according to any one of claims 1 to 7 or the electrowetting display device prepared by the preparation method according to any one of claims 8 to 9 in the field of electrowetting display, LED or LCD display technology.

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