Electrochromic display panels and electronic paper

Abstract

The present invention relates to an electrochromic display panel and electronic paper, comprising a first substrate, an electrochromic pixel array, and a second substrate, arranged in sequence. The electrochromic pixel array includes a plurality of independently controlled electrochromic units arranged in an array, each of which includes a first electrode, an electrochromic layer, and a second electrode, arranged in sequence. The first electrode has a first opposing surface opposite the second electrode, and the second electrode has a second opposing surface opposite the first electrode. The first opposing surface and / or the second opposing surface are provided with a plurality of micro-nano structures. The electrochromic display panel and electronic paper have micro-nano structures provided on the first electrode and / or the second electrode in the electrochromic pixel array, which can increase their contact area, resulting in better electrochemical performance and more uniform distribution of the electric field between the two electrodes, thereby enhancing their conductive effect and response speed. Furthermore, the electrochromic display panel and electronic paper have a simple structure and are easy to manufacture.

Description

Technical Field

[0001] The present invention relates to an electrochromic display panel and electronic paper, belonging to the field of display technology. Background Art

[0002] Electrochromism (EC) refers to the phenomenon in which a material's optical properties (reflectivity, transmittance, absorptivity, etc.) undergo a stable, reversible color change under the influence of an applied electric field, manifesting itself as a reversible change in color and transparency. Materials exhibiting electrochromic properties are called electrochromic materials, and devices made with electrochromic materials are called electrochromic devices. Electrochromic materials have been a hot topic in materials science research in recent years. Electrochromic materials are an important component of electrochromic devices and dominate their electrochromic performance. Based on the structural properties of the materials, electrochromic materials can be divided into anodic electrochromic materials (ion embedding coloration) and cathodic electrochromic materials (ion extraction coloration). Anodic and cathodic electrochromic materials can be assembled into complementary electrochromic devices, which can improve overall electrochromic properties such as optical contrast, color change, and spectral absorption range. Currently, existing electrochromic display panels and electronic paper have the following problems: the applied electric field is highly non-uniform, which affects the dielectric strength; under the same conditions, the more non-uniform the electric field, the lower the dielectric strength, making it easier for other materials to come into contact with the dielectric layer, resulting in corrosion reactions. Summary of the Invention

[0003] The object of the present invention is to provide an electrochromic display panel and electronic paper, which have uniform electric field distribution between electrodes, have better display effects, and are simple in structure and easy to prepare.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: an electrochromic display panel, comprising a first substrate, an electrochromic pixel array, and a second substrate arranged in sequence, wherein the electrochromic pixel array comprises a plurality of electrochromic units arranged in an array and independently controlled, wherein the electrochromic unit comprises a first electrode, an electrochromic pixel layer, and a second electrode arranged in sequence; the first electrode has a first opposing surface opposite to the second electrode, the second electrode has a second opposing surface opposite to the first electrode, and a plurality of micro-nano structures are provided on the first opposing surface and / or the second opposing surface.

[0005] Furthermore, the micro-nano structure is a concave-convex groove structure.

[0006] Furthermore, the groove widths of the concave-convex groove structure are the same or different; the groove depths are the same or different; and the groove shape is rectangular, trapezoidal, or arc-shaped.

[0007] Furthermore, the micro-nano structures are distributed periodically or non-periodically.

[0008] Furthermore, the electrochromic display panel further includes a white reflective layer, and the white reflective layer is disposed between the first substrate and the electrochromic pixel array.

[0009] Furthermore, the electrochromic display panel further includes an adhesive layer, which is disposed between the white reflective layer and the electrochromic pixel array, and the electrochromic pixel array is adhered to the white reflective layer through the adhesive layer.

[0010] Furthermore, the white reflective layer is formed of a viscous polymer resin and white particles, and the electrochromic pixel array is adhered to the white reflective layer.

[0011] Furthermore, the first electrode and / or the second electrode is a transparent electrode.

[0012] Furthermore, the electrochromic unit further includes an ion storage layer and a conductive layer stacked in sequence and arranged between the first electrode and the electrochromic pixel layer.

[0013] Furthermore, the ion storage layer and the conductive layer are solid-state structures.

[0014] Furthermore, the first electrode is embedded in the ion storage layer.

[0015] Furthermore, an electrochromic material is provided in the electrochromic pixel layer, and the electrochromic material is selected from any one or more of an organic electrochromic material, an inorganic electrochromic material or a composite electrochromic material.

[0016] Furthermore, the inorganic electrochromic material includes metal oxides, preferably tungsten trioxide and nickel oxide.

[0017] Furthermore, the organic electrochromic material is preferably any one or more of porogens, isophthalates, metal phthalocyanines, pyridine metal complexes, polyanilines, polypyrroles, and polythiophenes.

[0018] The present invention also provides an electronic paper comprising the above-mentioned electrochromic display panel.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the electrochromic display panel and electronic paper of the present invention are provided with a micro-nano structure on the first electrode and / or the second electrode in the electrochromic pixel array, which can increase its contact area, give it better electrochemical performance, and make the distribution of the electric field between the two electrodes more uniform, thereby enhancing its conductive effect and response speed, and its structure is simple and easy to prepare.

[0020] In addition, the electrochromic display panel and electronic paper fix the electrochromic pixel array on the white reflective layer by bonding, eliminating the packaging step of the liquid electrochromic material and avoiding the collapse of the electrode located above the gap due to pressure difference and the easy leakage, thereby saving production costs and improving product quality.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a top view of the electrochromic display panel shown in the present invention;

[0023] Figure 2a and Figure 2b Schematic diagram of the structure of the electrochromic display panel shown in the present invention;

[0024] Figure 3 and Figure 4 Schematic diagram of the structure of the micro-nano structure in the electrochromic display panel shown in the present invention;

[0025] Figure 5 is another structural schematic diagram of the electrochromic display panel shown in the present invention;

[0026] Figure 6 Schematic diagram of the structure of the electrochromic display panel shown in the first embodiment of the present invention;

[0027] Figure 7 Schematic diagram of the structure of the electrochromic display panel shown in the second embodiment of the present invention;

[0028] Figure 8 Schematic diagram of the structure of the electrochromic display panel shown in the third embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0030] It should be noted that the terms “upper”, “lower”, “left”, “right”, “inner” and “outer” in the present invention are only used to illustrate the present invention with reference to the drawings and are not intended to be limiting.

[0031] See Figure 1 and Figure 2aIn the vertical direction 10, the electrochromic display panel of the present invention includes a first substrate 1, an electrochromic pixel array layer 3 and a second substrate 4 arranged in sequence, the electrochromic pixel array layer 3 includes a plurality of array-arranged, independently controlled electrochromic units 30, the electrochromic unit 30 includes a first electrode 31, an electrochromic pixel layer 32 and a second electrode 33 arranged in sequence, wherein the first electrode 31 has a first opposing surface 311 opposite to the second electrode 33, the second electrode 33 has a second opposing surface 331 opposite to the first electrode 31, and a plurality of micro-nano structures 5 are provided on the first opposing surface 311 and / or the second opposing surface 331.

[0032] Please combine Figure 2b The electrochromic display panel of the present invention further includes a reflective layer 2, which is disposed between a first substrate 1 and an electrochromic pixel array layer 3. In the vertical direction 10, the electrochromic display panel includes, from bottom to top, a first substrate 1, a reflective layer 2, an electrochromic pixel array layer 3, and a second substrate 4, which are stacked in sequence. The electrochromic pixel array layer 3 includes a plurality of electrochromic units 30 arranged in an array and independently controlled. The electrochromic unit 30 includes a first electrode 31, an electrochromic pixel layer 32, and a second electrode 33, which are disposed in sequence. The first electrode 31 has a first opposing surface 311 opposing the second electrode 33, and the second electrode 33 has a second opposing surface 331 opposing the first electrode 31. A plurality of micro-nano structures 5 are provided on the first opposing surface 311 and / or the second opposing surface 331.

[0033] Here, the micro-nano structure 5 is provided on the second relative surface 331 as an example for explanation, which is not taken as its preferred or limited structure. In addition, the micro-nano structure 5 can be formed by methods such as photolithography, laser etching, and nanoimprinting. The existing first electrode 31 and the second electrode 33 are generally rectangular or circular in shape, and the first electrode 31 and the second electrode 33 are described as rectangular in shape. Taking into account the technical difficulty and cost, the micro-nano structure 5 is preferably a concave-convex groove structure, and the concave-convex groove structure 5 can be distributed periodically or non-periodically on the second electrode 33. In addition, the width of the groove of the concave-convex groove structure 5 is the same or different; the depth of the groove is the same or different; the shape of the groove is rectangular, trapezoidal, or arc-shaped.

[0034] Please combine Figure 3 When the concave-convex groove structure 5 is periodically distributed on the second opposite surface 331 of the second electrode 33, the electric field between the first electrode 31 and the second electrode 33 is uniformly distributed. Alternatively, please combine Figure 4Because the electric field at the edge of the second electrode 33 is more likely to be unevenly distributed, the concave-convex groove structure 5 is non-periodically distributed on the second opposing surface 331 of the second electrode 33, and the concave-convex groove structure 5 is more densely distributed near the edge of the second electrode 33 than near the center of the second electrode 33. Of course, the concave-convex groove structure 5 can also be provided solely on the first electrode 31, or on both the first electrode 31 and the second electrode 33. The first electrode 31 and the second electrode 33 can also be circular structures, and the arrangement method is the same as the above case, which will not be explained here.

[0035] In the present invention, the electrochromic unit 30 is further provided with a solid ion storage layer 34 and a conductive layer 35, which are sequentially stacked between the first electrode 31 and the electrochromic pixel layer 32. The ion storage layer 34 is provided on the first electrode 31, the conductive layer 35 is provided on the ion storage layer 34, and the electrochromic pixel layer 32 is provided on the conductive layer 35.

[0036] In the present invention, the white reflective layer 2 is formed by a polymer resin and white particles. The polymer resin can be selected from any one of phenolic resin, epoxy resin, polyamide resin, polyurethane resin or acrylic resin, and the white particles can be selected from any one or more of aluminum oxide, zinc oxide, titanium oxide or silicon dioxide. Figure 5 When the white reflective layer 2 is not sticky, an adhesive layer 21 can be provided between the white reflective layer 2 and the electrochromic pixel array 2 to adhere the electrochromic pixel array 3 to the white reflective layer 2, wherein the thickness of the white reflective layer 2 is preferably 1-40 μm, and the thickness of the adhesive layer 21 is preferably 1-40 μm. When the white reflective layer 2 is sticky, that is, a sticky polymer resin is selected, the electrochromic pixel array 3 can be directly adhered to the white reflective layer 2, wherein the thickness of the white reflective layer 2 is preferably 10-70 μm. This arrangement eliminates the need for encapsulating the liquid electrochromic material and avoids the phenomenon of the electrode located above the gap collapsing due to pressure difference and being prone to leakage. This not only ensures the stability and flatness of the electrochromic display panel with this structure, but also avoids or reduces the occurrence of Newton rings and other phenomena that are detrimental to the display effect.

[0037] The electrochromic pixel layer 32 of the present invention is provided with an electrochromic material, which is selected from any one of an organic electrochromic material, an inorganic electrochromic material or a composite electrochromic material, wherein the inorganic electrochromic material includes a metal oxide, preferably tungsten trioxide or nickel oxide; the organic electrochromic material is preferably any one or more of violaceous, isophthalic acid esters, metal phthalocyanines, pyridine metal complexes, polyanilines, polypyrroles, and polythiophenes, which can be prepared by sputtering, chemical vapor deposition, sol-gel or evaporation, or can be prepared by drying and solidifying liquid electrochromic materials. The first electrode 31 and the second electrode 33 of the present invention are transparent electrodes, selected from any one of indium tin oxide (ITO), fluorine-doped tin oxide (FTO) or a conductive polymer. The first substrate 1 and the second substrate 4 can be transparent inorganic substrates, such as quartz or glass, or transparent plastic, or other commonly used transparent materials.

[0038] The present invention further provides an electronic paper (not shown), which includes the above-mentioned electrochromic display panel, and the other structures are all existing technologies and will not be described here.

[0039] The present invention will be further described in detail below with reference to specific embodiments.

[0040] Example 1

[0041] See Figure 6 The electrochromic display panel shown in this embodiment includes a first substrate 1-1, an electrochromic pixel array 1-2, and a second substrate 1-3 arranged in sequence from bottom to top. The electrochromic pixel array layer 1-2 includes a plurality of electrochromic units 1-20 arranged in an array and independently controlled. The electrochromic unit 1-20 includes a first transparent electrode 1-21, an ion storage layer 1-22, a conductive layer 1-23, an electrochromic pixel layer 1-24, and a second transparent electrode 1-25 arranged in sequence from bottom to top. The first transparent electrode 1-21 has a first opposing surface 1-211 that opposes the second transparent electrode 1-25, and the second transparent electrode 1-25 has a second opposing surface 1-251 that opposes the first transparent electrode 1-21. To achieve a more uniform electric field distribution between the first transparent electrode 1-21 and the second transparent electrode 1-25, this embodiment provides a plurality of concave-convex groove structures 1-4 on the first opposing surface 1-211 and the second opposing surface 1-251. The concave-convex groove structures 1-4 are more closely distributed near the edges of the transparent electrodes. This arrangement avoids electric field boundary effects and achieves a more uniform electric field distribution. Furthermore, the grooves of the concave-convex groove structures 1-4 have the same width and depth, and are rectangular in shape.

[0042] In this embodiment, the first transparent electrode 1-21 and the second transparent electrode 1-25 are both rectangular structures. Of course, in other embodiments, they may also be circular structures. The concave-convex groove structure 1-4 of this embodiment is provided on the first transparent electrode 1-21 and the second transparent electrode 1-25. Of course, in other embodiments, the concave-convex groove structure 1-4 may also be provided on either the first transparent electrode 1-21 or the second transparent electrode 1-25.

[0043] Example 2

[0044] See Figure 7 The electrochromic display panel shown in this embodiment includes a first substrate 2-1, an electrochromic pixel array 2-2, and a second substrate 2-3 arranged in sequence from bottom to top. The electrochromic pixel array layer 2-2 includes a plurality of electrochromic units 2-20 arranged in an array and independently controlled. The electrochromic unit 2-20 includes a first transparent electrode 2-21, an ion storage layer 2-22, a conductive layer 2-23, an electrochromic pixel layer 2-24, and a second transparent electrode 2-25 arranged in sequence from bottom to top. The first transparent electrode 2-21 has a first opposing surface 2-211 that opposes the second transparent electrode 2-25, and the second transparent electrode 2-25 has a second opposing surface 2-251 that opposes the first transparent electrode 2-21. To achieve a more uniform electric field distribution between the first transparent electrode 2-21 and the second transparent electrode 2-25, this embodiment provides a plurality of periodically distributed concave-convex groove structures 2-4 on the first opposing surface 2-211 and the second opposing surface 2-251. The concave-convex groove structures 2-4 are evenly distributed on the second transparent electrode 2-25. Furthermore, the grooves of the concave-convex groove structures 2-4 have the same width and depth, and are rectangular in shape.

[0045] In this embodiment, the first transparent electrode 2-21 and the second transparent electrode 2-25 are both rectangular structures. Of course, in other embodiments, they can also be circular structures. The concave-convex groove structure 2-4 of this embodiment is provided on the first transparent electrode 2-21 and the second transparent electrode 2-25. Of course, in other embodiments, the concave-convex groove structure 2-4 can also be provided on the first transparent electrode 2-21 or the second transparent electrode 2-25 alone.

[0046] Example 3

[0047] See Figure 8The structure of the electrochromic display panel of this embodiment is substantially the same as that of the first embodiment, with the difference being that a white reflective layer 3-5 and an adhesive layer 3-51 are disposed between the first substrate 3-1 and the electrochromic pixel array 3-2. In this embodiment, the white reflective layer 3-5 is composed of a phenolic resin and dispersed titanium oxide and is applied to the first substrate 3-1 by spin coating. Furthermore, the thickness of the white reflective layer 3-5 is 20 μm, and the thickness of the adhesive layer 3-51 is 15 μm. Compared to using a sticky white reflective layer to adhere the electrochromic pixel array 3-2, the provision of the adhesive layer 3-51 achieves a better adhesion effect, allowing the electrochromic pixel array 3-2 to be more stably fixed to the white reflective layer 3-5.

[0048] In summary, the electrochromic display panel and electronic paper of the present invention incorporate micro-nanostructures on the first and / or second transparent electrodes in the electrochromic pixel array, increasing their contact area, resulting in better electrochemical performance and a more uniform distribution of the electric field between the two electrodes, thereby enhancing their conductivity and response speed. Furthermore, the electrochromic display panel and electronic paper feature a simple structure and are easy to manufacture. Furthermore, by adhesively attaching the electrochromic pixel array to the white reflective layer, the electrochromic display panel and electronic paper eliminate the need for encapsulating the liquid electrochromic material and prevent the electrodes above the gap from collapsing due to pressure differentials and potentially leaking. This reduces production costs and improves product quality.

[0049] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An electrochromic display panel, characterized in that: The invention comprises a first substrate, an electrochromic pixel array, and a second substrate arranged in sequence, wherein the electrochromic pixel array comprises a plurality of electrochromic units arranged in an array and independently controlled, wherein the electrochromic units comprise a first electrode, an electrochromic pixel layer, and a second electrode arranged in sequence; the first electrode has a first opposing surface opposite to the second electrode, the second electrode has a second opposing surface opposite to the first electrode, and a plurality of micro-nano structures are provided on the first opposing surface and / or the second opposing surface; The electrochromic unit further includes an ion storage layer and a conductive layer stacked in sequence and arranged between the first electrode and the electrochromic pixel layer; The micro-nano structure is a concave-convex groove structure; The micro-nano structures are distributed non-periodically; The concave-convex groove structure is arranged so that the density near the edge of the first electrode or the second electrode is greater than the density in the middle.

2. The electrochromic display panel according to claim 1, wherein: The groove widths of the concave-convex groove structure are the same or different; the groove depths are the same or different; and the groove shape is rectangular, trapezoidal, or arc-shaped.

3. The electrochromic display panel according to claim 1, wherein: The electrochromic display panel further includes a white reflective layer, which is disposed between the first substrate and the electrochromic pixel array.

4. The electrochromic display panel according to claim 3, wherein: The electrochromic display panel further includes an adhesive layer, which is disposed between the white reflective layer and the electrochromic pixel array. The electrochromic pixel array adheres to the white reflective layer via the adhesive layer.

5. The electrochromic display panel according to claim 3, wherein: The white reflective layer is formed of a viscous polymer resin and white particles, and the electrochromic pixel array is adhered to the white reflective layer.

6. The electrochromic display panel according to claim 1, wherein: The first electrode and / or the second electrode is a transparent electrode.

7. The electrochromic display panel according to claim 6, wherein: The ion storage layer and the conductive layer are solid structures.

8. The electrochromic display panel according to claim 6, wherein: The first electrode is embedded in the ion storage layer.

9. The electrochromic display panel according to claim 1, wherein: The electrochromic pixel layer is provided with an electrochromic material, and the electrochromic material is selected from any one or more of an organic electrochromic material, an inorganic electrochromic material or a composite electrochromic material.

10. The electrochromic display panel according to claim 9, wherein: The inorganic electrochromic material includes a metal oxide, and the metal oxide includes tungsten trioxide or nickel oxide.

11. The electrochromic display panel according to claim 9, wherein: The organic electrochromic material is any one or more of porogens, isophthalates, metal phthalocyanines, pyridine metal complexes, polyanilines, polypyrroles, and polythiophenes.

12. An electronic paper, characterized in that: The invention comprises the electrochromic display panel according to any one of claims 1 to 11.

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