Electro-optical device comprising barrier layer

Abstract

An electro-optical device is disclosed comprising a layer of electro-optical material, a barrier layer adjacent the layer of electro-optical material, and an adhesive layer comprising a dopant, where the layer of electro-optical material, the barrier layer, and the adhesive layer are disposed between two electrode layers. The barrier layer prevents or reduces diffusion of dopants and other materials from one layer to another of the electro-optical device, prevents degradation of components of the device, and achieves good electro-optical performance.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 541,356, filed September 29, 2023, which is incorporated in its entirety by reference, along with all other patents and patent applications disclosed herein. Background of the Invention

[0004] This invention relates to an electro-optic device comprising an electro-optic material layer, a barrier layer adjacent to the electro-optic material layer, and an adhesive layer containing dopants, wherein the electro-optic material layer, the barrier layer, and the adhesive layer are disposed between two electrode layers. The barrier layer prevents or reduces the diffusion of dopants and other materials from one layer of the electro-optic device to another, thereby maintaining good electro-optic performance of the electro-optic device.

[0005] When applied to materials, devices, displays, or components, the term "electro-optic" is used herein in its conventional meaning in the field of imaging to refer to a material having a first display state and a second display state that differ in at least one optical property, which is altered from its first display state to its second display state by applying an electric field to the material. While the optical property is typically color perceptible to the human eye, it can be another optical property, such as transmittance, reflectivity, luminescence, or, in the case of a display intended for machine reading, pseudocolor, in the sense of a change in reflectivity at electromagnetic wavelengths outside the visible light range. The terms "electro-optic device" and "electro-optic display" are considered synonymous herein. As used herein, the term "electro-optic assembly" can refer to an electro-optic device. It can also refer to multilayer components used to construct an electro-optic device. Thus, for example, the front panel laminate described below is also considered an electro-optic assembly.

[0006] The term "grayscale" is used herein in its conventional sense within the imaging field to refer to an intermediate state between two extreme display states of a pixel, and does not necessarily imply a black-and-white transition between these two extreme states. For example, several E Ink patents and published applications mentioned below describe electrophoretic displays where the extreme states are white and dark blue, making the intermediate "grayscale" actually a pale blue. In reality, as already mentioned, a change in display state may not be a color change at all. The terms "black" and "white" can be used below to refer to two extreme display states of a display and should be understood to generally include extreme display states that are not strictly black and white, such as the aforementioned white and dark blue states. The term "monochrome" can be used below to refer to a driving scheme that drives pixels only to their two extreme display states without an intermediate grayscale state.

[0007] Some electro-optic materials are solid in the sense that they have a solid external surface, although such materials may and often have internal liquid- or gas-filled spaces. For convenience, such displays using solid electro-optic materials will be referred to as "solid-state electro-optic displays" below. Therefore, the term "solid-state electro-optic display" includes rotating dual-color element displays, encapsulated electrophoretic displays, microcell electrophoretic displays, and encapsulated liquid crystal displays.

[0008] The terms “bistable” and “bistable” are used herein in their conventional sense to refer to a display comprising display elements having a first display state and a second display state that are different in at least one optical property, such that after either given element has been driven to present its first or second display state by an addressing pulse of finite duration, the state will persist for at least several times, for example, at least four times, the minimum duration of the addressing pulse required to change the state of the display element after the addressing pulse has terminated. U.S. Patent No. 7,170,670 shows that some particle-based electrophoretic displays capable of displaying grayscale are stable not only in their extreme black and white states but also in their intermediate gray states, as are some other types of electro-optic displays. This type of display is properly referred to as “multistable” rather than bistable; however, for convenience, the term “bistable” may be used herein to encompass both bistable and multistable displays.

[0009] Several types of electro-optic displays are known. One type of electro-optic display is the rotating bicolor element type, as described, for example, in U.S. Patents Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071; 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791. Although this type of display is often referred to as a “rotating bicolor sphere” display, the term “rotating bicolor element” is preferred because it is more accurate, since in some of the aforementioned patents, the rotating element is not spherical. Such displays utilize a large number of small bodies (typically spherical or cylindrical) having two or more portions with different optical properties, as well as internal dipoles. These small bodies are suspended in vesicles filled with liquid within a matrix, allowing the small bodies to rotate freely. By applying an electric field, the volume is rotated to different positions, thus altering the appearance of the display by changing which part of the volume is seen through the viewing surface. This type of electro-optic medium is typically bistable.

[0010] Another type of electro-optic display uses an electrochromic medium, such as an electrochromic medium in the form of a nanochromic film, which includes an electrode at least partially formed of a semiconductor metal oxide, and a plurality of dye molecules attached to the electrode capable of reversibly changing color; see, for example, O'Regan, B., et al., Nature 1991, 353,737; and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. This type of nanochromic film is also described, for example, in U.S. Patents 6,301,038, 6,870,657 and 6,950,220. This type of medium is also typically bistable.

[0011] Another type of electro-optic display is the electrowetting display developed by Philips and described in Hayes, RA, et al., “Video-Speed ​​Electronic Paper Based on Electrowetting”, Nature, 425, 383-385 (2003). U.S. Patent No. 7,420,549 shows that such an electrowetting display can be fabricated to be bistable.

[0012] Electro-optic displays, a type of display that has been the subject of in-depth research and development for many years, are particle-based electrophoretic displays, in which multiple charged particles move through a liquid under the influence of an electric field. Compared to liquid crystal displays (LCDs), electrophoretic displays can offer advantages such as good brightness and contrast, wide viewing angles, bistable states, and low power consumption. However, long-term image quality issues have hindered their widespread application. For example, the particles constituting an electrophoretic display tend to settle, leading to a short lifespan for these displays.

[0013] As mentioned above, electrophoretic media require the presence of a fluid. In most prior art electrophoretic media, this fluid is a liquid, but gaseous fluids can also be used to produce electrophoretic media; see, for example, Kitamura, T., et al., “Electrical toner movement for electronic paper-like display”, IDW Japan, 2001, Paper HCS1-1, and Yamaguchi, Y., et al., “Toner display using insulative particles charged triboelectrically”, IDW Japan, 2001, Paper AMD4-4. See also U.S. Patents 7,321,459 and 7,236,291. When such gas-based electrophoretic media are used in orientations that allow particle sedimentation, for example, in a sign where the media is positioned in a vertical plane, the media appears susceptible to the same type of problems caused by such sedimentation as those with liquid-based electrophoretic media. In fact, particle sedimentation appears to be a more serious problem in gas-based electrophoresis media than in liquid-based electrophoresis media because the lower viscosity of gaseous suspensions compared to liquid suspensions causes electrophoretic particles to settle more quickly.

[0014] Numerous patents and applications assigned to or attributed to MIT, E Ink Corporation, E Ink California, LLC., and related companies describe various techniques used in encapsulated electrophoretic media and microcell electrophoretic media, as well as other electro-optic media. Encapsulated electrophoretic media comprise a plurality of vesicles, each vesicle itself comprising an inner phase and a vesicle wall surrounding the inner phase, which contains particles that electrophoretically move in a liquid medium. Typically, the vesicles themselves are held in a polymer binder to form a coherent layer between two electrodes. In microcell electrophoretic displays, the charged particles and liquid are not encapsulated within microcapsules but are retained within a carrier medium, typically a polymer film, within multiple cavities. Hereinafter, the term "microcavity electrophoretic display" may be used to encompass both encapsulated electrophoretic displays and microcell electrophoretic displays. The techniques described in these patents and applications include:

[0015] (a) Electrophoretic particles, fluids, and fluid additives; see, for example, U.S. Patents 7,002,728 and 7,679,814.

[0016] (b) Encapsulation, adhesives, and encapsulation methods; see, for example, U.S. Patents 6,922,276, 7,184,197, and 7,411,719.

[0017] (c) Microunit structures, wall materials, and methods of forming microunits; see, for example, U.S. Patents 7,072,095 and 9,279,906.

[0018] (d) Methods for filling and sealing microcells; see, for example, U.S. Patents 7,144,942 and 7,715,088.

[0019] (e) Films and subassemblies containing electro-optic materials; see, for example, U.S. Patents 6,982,178 and 7,839,564.

[0020] (f) Backplates, adhesive layers and other auxiliary layers used in displays, and methods thereof; see, for example, U.S. Patents 7,116,318, 7,535,624, 7,012,735 and 7,173,752.

[0021] (g) Color formation and color adjustment; see, for example, U.S. Patents 7,075,502 and 7,839,564.

[0022] (h) A method for driving a display; see, for example, U.S. Patents 7,012,600 and 7,453,445.

[0023] (i) Applications of displays; see, for example, U.S. Patents 7,312,784 and 8,009,348.

[0024] (j) Non-electrophoretic displays, as described in U.S. Patent No. 6,241,921 and U.S. Patent Application Publication No. 2015 / 0277160; and applications of packaging and microcell technologies other than displays; see, for example, U.S. Patent Application Publication Nos. 2015 / 0005720 and 2016 / 0012710.

[0025] Many of the aforementioned patents and applications recognize that the walls surrounding discrete microcapsules in an encapsulated electrophoretic medium can be replaced by a continuous phase, thereby producing what is known as a polymer-dispersed electrophoretic display. In such a display, the electrophoretic medium comprises a plurality of discrete droplets of electrophoretic liquid and a continuous phase of polymeric material. The discrete droplets of electrophoretic liquid within such a polymer-dispersed electrophoretic display can be considered as capsules or microcapsules, although the discrete capsule membrane is not associated with each individual droplet; see, for example, U.S. Patent No. 6,866,760. Therefore, for the purposes of this application, such polymer-dispersed electrophoretic media are considered a subtype of encapsulated electrophoretic media.

[0026] Although electrophoretic media are often opaque (because, for example, in many electrophoretic media, the particles essentially block visible light from passing through the display) and operate in a reflective mode, many electrophoretic displays can be made to operate in a so-called "shutter mode," where one display state is substantially opaque and the other is transparent. See, for example, U.S. Patents 5,872,552; 6,130,774, 6,144,361, 6,172,798, 6,271,823, 6,225,971, and 6,184,856. Dielectric electrophoretic displays, similar to electrophoretic displays but dependent on changes in electric field strength, can operate in a similar mode; see U.S. Patent 4,418,346. Other types of electro-optic displays can also be able to operate in a shutter mode. Electro-optic media operating in shutter mode can be used in multilayer structures for full-color displays; in such structures, at least one layer adjacent to the viewing surface of the display operates in shutter mode to expose or hide a second layer further away from the viewing surface.

[0027] Encapsulated electrophoretic displays typically do not suffer from the aggregation and sedimentation failure modes of conventional electrophoretic apparatus and offer further advantages, such as the ability to print or coat the display onto a wide variety of flexible and rigid substrates. The term "printing" is used to encompass all forms of printing and coating, including but not limited to: volumetric coating, such as patch die coating, slot or extrusion coating, cascade coating, curtain coating; roll coating, such as doctor blade coating, clockwise and counterclockwise roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; screen printing; electrostatic printing; thermal printing; inkjet printing; electrophoretic deposition (see U.S. Patent No. 7,339,715); and other similar techniques. Therefore, the resulting display can be flexible. Furthermore, because various methods can be used to print the display media, the display can be manufactured at low cost.

[0028] Other types of electro-optic materials can also be used in this invention. Of particular interest are bistable ferroelectric liquid crystal displays (FLCs), which are known in the art.

[0029] In addition to the electro-optic material layer, electrophoretic displays typically include at least two other layers disposed on opposite sides of the electro-optic material layer. One of these layers is an electrode layer. In most electro-optic devices, both layers are electrode layers, and at least one electrode layer is patterned to define pixels of the device. For example, one electrode layer may be patterned as an elongated row electrode, and the other electrode layer may be patterned as an elongated column electrode extending perpendicularly to the row electrode, with pixels defined by the intersection of the row and column electrodes. Alternatively and more commonly, one electrode layer has the form of a transparent, single, continuous electrode, and the other electrode layer is patterned as a matrix of pixel electrodes, each pixel electrode defining a pixel of the display. That is, one of the layers is typically a conductive transparent layer, and the other layer, often referred to as a backplane substrate, comprises a plurality of pixel electrodes configured to apply a potential between the conductive transparent layer and the pixel electrodes. Another type of electro-optic device is designed to be used with a stylus, printhead, or similar movable electrodes separate from the display, in which only one of the layers adjacent to the electro-optic layer contains the electrodes, and the layer on the opposite side of the electro-optic layer is usually a protective layer designed to prevent the movable electrodes from damaging the electro-optic material layer.

[0030] The fabrication of three-layer electro-optic displays typically involves at least one lamination operation. For example, several of the aforementioned MIT and E Ink patents and applications describe methods for fabricating encapsulated electrophoretic displays, wherein an encapsulated electrophoretic medium containing a capsule in an adhesive is coated onto a flexible substrate, the flexible substrate containing an indium tin oxide (ITO) or similar conductive coating on a plastic film (which serves as an electrode of the final display), and the capsule / adhesive coating is dried to form a coherent layer of electrophoretic medium firmly adhered to the substrate. A backplane is fabricated separately, the backplane containing an array of pixel electrodes and a suitable conductor arrangement to connect the pixel electrodes to driving circuitry. To form the final display, a substrate with the capsule / adhesive layer on it is laminated to the backplane using a lamination adhesive. A very similar method can be used to fabricate electrophoretic displays that can be used with a stylus or similar movable electrodes on which the stylus or other movable electrodes can slide, by replacing the backplane with a simple protective layer, such as a plastic film. In a preferred form of such a method, the backplane itself is flexible and is fabricated by printing the pixel electrodes and conductors onto a plastic film or other flexible substrate. The obvious lamination technique for mass-producing displays using this method is roller lamination using laminating adhesives. Similar manufacturing techniques can be used for other types of electro-optic displays. For example, microcell electrophoretic media or rotating dual-color element media can be laminated to a backplane in essentially the same way as encapsulated electrophoretic media.

[0031] The aforementioned U.S. Patent No. 6,982,178 describes a method for assembling a solid-state electro-optic display (including an encapsulated electrophoretic display), a method well-suited for mass production. Essentially, the patent describes a so-called “front panel laminate” (“FPL”) comprising, in sequence: a light-transmitting conductive layer; a solid electro-optic dielectric layer; an adhesive layer; and a release sheet. Typically, the light-transmitting conductive layer is carried on a light-transmitting substrate, which is preferably flexible, meaning that it can be manually wound around a roller with a diameter of approximately 10 inches (254 mm) without permanent deformation. As used in the patent and herein, the term “light-transmitting” means that the layer, as defined herein, transmits sufficient light to allow a viewer to see through it to observe changes in the display state of the electro-optic dielectric, typically through the conductive layer and an adjacent substrate (if present); where the electro-optic dielectric exhibits a change in reflectivity at non-visible wavelengths, the term “light-transmitting” should, of course, be interpreted as referring to the transmission of the relevant non-visible wavelengths. The substrate is typically a polymer film and usually has a thickness ranging from about 1 to about 25 mils (25 to 634 μm), preferably from about 2 to about 10 mils (51 to 254 μm). The conductive layer is preferably a thin metal or metal oxide layer, such as an aluminum or ITO layer, or it may be a conductive polymer. Poly(ethylene terephthalate) (PET) films coated with aluminum or ITO are commercially available, for example, from El du Pont de Nemours & Company of Wilmington, Delaware, under the name "aluminized Mylar" ("Mylar" is a registered trademark), and such commercial materials can be used in front panel laminates with good results.

[0032] Assembling an electro-optic display using such a front-panel laminate can be achieved by removing the release liner from the front-panel laminate and bringing the adhesive layer into contact with the backplate while effectively adhering the adhesive layer to the backplate, thereby fixing the adhesive layer, electro-optic dielectric layer, and conductive layer to the backplate. This method is well-suited for mass production because the front-panel laminate can be mass-produced, typically using roll-to-roll coating technology, and then cut into sheets of any size required for use with a specific backplate.

[0033] U.S. Patent No. 7,561,324 describes a so-called "dual release film" or "dual release sheet," which is essentially a simplified version of the front panel laminate of the aforementioned U.S. Patent No. 6,982,178. One form of the dual release film includes a solid electro-optic dielectric layer sandwiched between two adhesive layers, wherein one or both of the adhesive layers are covered by a release sheet. Another form of the dual release film includes a solid electro-optic dielectric layer sandwiched between two release sheets. Both forms of dual release films are intended for use in methods generally similar to those used for assembling electro-optic displays from the already described front panel laminate, but involving two separate laminations; typically, in the first lamination, the dual release film is laminated to the front electrode to form a front sub-assembly, and then in the second lamination, the front sub-assembly is laminated to the back panel to form the final display, although the order of these two laminations can be reversed if desired.

[0034] As an alternative structure, U.S. Patent No. 7,839,564 describes a so-called "inverted front panel laminate," a variation of the front panel laminate described in U.S. Patent No. 6,982,178. This inverted front panel laminate sequentially comprises: at least one of a light-transmitting protective layer and a light-transmitting conductive layer; an adhesive layer; a solid electro-optic dielectric layer; and a release liner. This inverted front panel laminate is used to form an electro-optic display having a laminated adhesive layer between the electro-optic layer and the front electrode or front substrate; a second, typically thin, adhesive layer may or may not be present between the electro-optic layer and the backplate.

[0035] Performance criteria for electro-optic devices include consistency performance over time and at various temperatures, image resolution, and device lifetime. The individual layers of an electro-optic device comprise materials with relatively small molecules, allowing them to diffuse from one layer to another. This diffusion can lead to performance degradation and a shortened device lifetime. For example, an electrophoretic display may include two (or more) different adhesive layers, a first adhesive layer and a second adhesive layer. Typically, the two adhesive layers have different compositions, such as different dopant concentrations. The first adhesive layer connects the electro-optic material layer to the back electrode, i.e., the electrode comprising multiple pixel electrodes, while the second adhesive composition connects the electro-optic material layer to the front electrode. The second adhesive layer is typically more conductive than the first adhesive layer. That is, the second adhesive layer typically contains a higher concentration of dopant. Importantly, the first adhesive layer does not have high conductivity, as such high conductivity increases halogenation, which negatively impacts image resolution. Halogenation is the phenomenon where the area of ​​the electro-optic material layer that changes its optical state in response to voltage changes at the pixel electrode is larger than the pixel electrode itself. If dopant molecules diffuse from the second adhesive layer to the first adhesive layer, the dopant concentration in the first adhesive layer increases, and as a result, smearing increases, reducing the resolution of the device. Generally, material diffusion from one layer of a device to another can also degrade other components of the device, reducing its lifespan. The inventors of this invention have discovered that a barrier layer of controllable thickness can be effectively formed near the electro-optic material layer of the electro-optic device. Furthermore, the inventors of this invention have unexpectedly discovered that the presence of a barrier layer near the electro-optic material layer of the electro-optic device improves the low-temperature performance of the device. Specifically, the device of this invention, including the barrier layer, has been observed to exhibit reduced flicker when transitioning from one optical state to another. Invention Overview

[0037] Several aspects of the present invention relate to adhesive compositions and electro-optical components and front panel laminates comprising these adhesive compositions.

[0038] On one hand, the present invention provides an electro-optic device, which can be of type (A) or type (B). The type (A) electro-optic device sequentially comprises a first transparent electrode layer, a barrier layer, an electro-optic material layer, a first adhesive layer, and a second electrode layer. The barrier layer of the type (A) electro-optic device is transparent. The electro-optic material layer contains an electrophoretic medium comprising charged pigment particles in a non-polar liquid. The first adhesive layer contains a first dopant having a first concentration. The first dopant can be an ionic liquid. The second electrode layer comprises a plurality of pixel electrodes. The first concentration of the first dopant in the first adhesive layer can be from 50 ppm to 1000 ppm by weight of the first adhesive layer. The first adhesive layer can contain polyurethane.

[0039] The (B) type electro-optic device sequentially comprises a first transparent electrode layer, an electro-optic material layer, a barrier layer, a first adhesive layer, and a second electrode layer. The barrier layer of the (B) type electro-optic device does not need to be transparent. The electro-optic material layer comprises an electrophoretic medium containing charged pigment particles in a non-polar liquid. The first adhesive layer contains a first dopant at a first concentration. The first dopant may be an ionic liquid. The second electrode layer comprises a plurality of pixel electrodes. The first concentration of the first dopant in the first adhesive layer may be from 50 ppm to 1000 ppm by weight of the first adhesive layer. The first adhesive layer may comprise polyurethane.

[0040] For both Type A and Type B electro-optic devices of this invention, the electrophoretic medium may be encapsulated in multiple microcapsules or multiple microunits. Each microunit includes a partition wall, an opening, and a sealing layer, the sealing layer spanning the opening of each microunit. In the electro-optic device where the electrophoretic medium is encapsulated in multiple microcapsules, the electro-optic device may further include a second adhesive layer. In the Type A electro-optic device, the second adhesive layer is disposed between the first electrode layer and the barrier layer. In the Type B electro-optic device, the second adhesive layer is disposed between the first electrode layer and the electro-optic material layer. The second adhesive layer may contain a second dopant having a second concentration. The first dopant may be the same as or different from the second dopant. The first concentration of the first dopant in the first adhesive layer may be a concentration lower than the second concentration of the second dopant in the second adhesive layer. The second concentration of the second dopant in the second adhesive layer may be from 1000 ppm to 5000 ppm by weight of the first adhesive layer. The second dopant may be an ionic liquid. The second adhesive layer may contain polyurethane.

[0041] The barrier layer can be formed by sputtering or chemical vapor deposition. The average thickness of the barrier layer can be from 5 nm to 200 nm. The barrier layer can contain a material selected from silicon dioxide, aluminum oxide, aluminum nitride, titanium nitride, titanium oxide, silicon nitride, indium tungsten oxide, metals, and mixtures thereof. If the barrier layer contains a metal, the metal can be iron, titanium, germanium, vanadium, tungsten, silicon, silver, nickel, niobium, chromium, gold, and mixtures thereof. If the barrier layer contains a metal, the average thickness of the barrier layer can be from 5 nm to 30 nm.

[0042] On the other hand, the present invention provides an electro-optic component, which sequentially includes a first substrate, a first light-transmitting electrode layer, a barrier layer, an electro-optic material layer, a first adhesive layer containing a first dopant having a first concentration, and a release sheet. The barrier layer is light-transmitting.

[0043] On the other hand, the present invention provides an electro-optic component, which sequentially includes a first release sheet, a second adhesive layer containing a second dopant having a second concentration, a barrier layer, an electro-optic material layer, a first adhesive layer containing a first dopant having a first concentration, and a second release sheet. The barrier layer is light-transmitting.

[0044] On the other hand, the present invention provides an electro-optic component, which sequentially includes a first substrate, a first light-transmitting electrode layer, an electro-optic material layer, a barrier layer, a first adhesive layer containing a first dopant having a first concentration, and a release sheet. The barrier layer may be light-transmitting or opaque.

[0045] On the other hand, the present invention provides an electro-optic component, which sequentially includes a first release sheet, a second adhesive layer containing a second dopant having a second concentration, an electro-optic material layer, a barrier layer, a first adhesive layer containing a first dopant having a first concentration, and a second release sheet. The barrier layer may be light-transmitting or light-opaque.

[0046] On the other hand, the present invention provides a method for manufacturing an electro-optic device, the method comprising the following steps: (a) providing a first electrode layer having a surface, the first electrode layer including a light-transmitting electrode; (b) coating an electro-optic material slurry onto the surface of the first electrode layer, the electro-optic material slurry comprising a plurality of microcapsules and an adhesive, each of the plurality of microcapsules containing charged particles in a nonpolar liquid; (c) curing the adhesive to form an electro-optic material layer on the surface of the first electrode layer; and (d) forming an electro-optic material layer on the electro-optic material via sputtering a barrier material or via chemical vapor deposition of a barrier material. (e) applying a first adhesive composition to the barrier layer; (f) curing the adhesive composition to form a first adhesive layer; (g) attaching a first release liner to the first adhesive layer; (h) providing a second electrode including a plurality of pixel electrodes; removing the first release liner to expose the surface of the first adhesive layer; (i) attaching the second electrode to the first adhesive layer; (j) providing a first light-transmitting electrode; (k) removing a second release liner to expose the surface of a second adhesive layer; (i) attaching the first light-transmitting electrode to the first adhesive layer.

[0047] On the other hand, the present invention provides a method for manufacturing an electro-optic device, the method comprising the steps of: (a) providing a first electrode layer having a surface, the first electrode layer including a light-transmitting electrode; (b) forming a barrier layer on the surface of the first electrode layer by sputtering a barrier material or by chemical vapor deposition of a barrier material; (c) coating an electro-optic material slurry onto the surface of the barrier layer, the electro-optic material slurry comprising a plurality of microcapsules and an adhesive, each of the plurality of microcapsules containing charged particles in a nonpolar liquid; and (d) curing the adhesive to form an electro-optic material on the surface of the first electrode layer. (e) Applying a first adhesive composition to the electro-optic material layer; (f) Curing the adhesive composition to produce a first adhesive layer; (g) Attaching a first release sheet to the first adhesive layer; (h) Providing a second electrode including a plurality of pixel electrodes; Removing the first release sheet to expose the surface of the first adhesive layer; (i) Attaching the second electrode to the first adhesive layer; (j) Providing a first light-transmitting electrode; (k) Removing the second release sheet to expose the surface of the second adhesive layer; (i) Attaching the first light-transmitting electrode to the first adhesive layer.

[0048] On the other hand, the present invention provides a method for manufacturing an electro-optic device, the method comprising the following steps: (a) providing a third release sheet; (b) coating an electro-optic material slurry onto the third release sheet, the slurry comprising a plurality of microcapsules and an adhesive, each of the plurality of microcapsules containing charged particles in a nonpolar liquid; (c) curing the electro-optic material slurry to form an electro-optic material layer on the third release sheet; and (d) forming a barrier layer on the electro-optic material layer by sputtering a barrier material or by chemical vapor deposition of a barrier material, to form a structure comprising, in sequence, the barrier layer, the... (e) providing a second release sheet; (f) coating a second adhesive composition onto the second release sheet; (g) curing the second adhesive composition to produce a second adhesive layer; (h) attaching a fourth release sheet to the first adhesive layer to form a second release structure, the second release structure comprising a fourth release sheet, a second adhesive layer, and a second release sheet in sequence; (i) removing the fourth release sheet from the second release structure to expose the surface of the second adhesive layer of the second release structure; (j) exposing the second adhesive layer. The surface is connected to the barrier layer of the electro-optic material film to form an intermediate electro-optic structure, the intermediate electro-optic structure comprising a second release sheet, a second adhesive layer, a barrier layer, an electro-optic material layer, and a third release sheet in sequence; (k) providing a first release sheet; (l) coating a first adhesive composition onto the first release sheet; (m) curing the first adhesive composition to produce a first adhesive layer to form a first release structure comprising the first adhesive layer and the first release sheet; (n) removing the third release sheet from the intermediate electro-optic structure to expose the surface of the electro-optic material layer; (o) ... The exposed surface of the electro-optic material layer is connected to the first adhesive layer of the first release structure to form a double release sheet; (p) a second electrode is provided; (q) the first release sheet of the double release sheet is removed to expose the surface of the first adhesive layer; (r) the exposed surface of the first adhesive layer is connected to the second electrode to form an intermediate electro-optic web; (s) a first light-transmitting electrode is provided; (t) the second release sheet of the intermediate electro-optic web is removed to expose the surface of the second adhesive layer; (u) the exposed surface of the second adhesive layer is connected to the first light-transmitting electrode.

[0049] On the other hand, the present invention provides a method for manufacturing an electro-optic device, comprising the following steps: (a) providing a third release sheet; (b) coating an electro-optic material slurry onto the third release sheet, the slurry comprising a plurality of microcapsules and an adhesive, each of the plurality of microcapsules containing charged particles in a nonpolar liquid; (c) curing the electro-optic material slurry to form an electro-optic material layer on the third release sheet; and (d) forming a barrier layer on the electro-optic material layer by sputtering a barrier material or by chemical vapor deposition of a barrier material. (e) forming an electro-optic material film comprising, in sequence, the barrier layer, the electro-optic material layer, and the third release sheet; (f) providing a first release sheet; (g) coating a first adhesive composition onto the first release sheet; (h) curing the first adhesive composition to produce a first adhesive layer; (i) attaching a fourth release sheet to the first adhesive composition to form a first release assembly, the first release assembly comprising, in sequence, a fourth release sheet, a first adhesive layer, and a first release sheet; (j) removing the fourth release sheet from the first release assembly to expose the surface of the first adhesive layer; and (e) attaching the first release sheet to the first release assembly. The exposed surface of the adhesive layer is connected to the barrier layer of the electro-optic material film to form an intermediate electro-optic assembly, the intermediate electro-optic assembly sequentially comprising a first release sheet, a first adhesive layer, a barrier layer, an electro-optic material layer, and a third release sheet; (k) providing a second release sheet; (l) coating a second adhesive composition onto the second release sheet; (m) curing the second adhesive composition to produce a second adhesive layer to form a second release assembly comprising the second adhesive layer and the second release sheet; (n) removing the third release sheet from the intermediate electro-optic assembly to expose the surface of the electro-optic material layer; (o) (p) Connecting the exposed surface of the electro-optic material layer of the intermediate electro-optic component to the second adhesive composition of the second release component to form a double release film; (q) Providing a second electrode; (r) Removing the first release sheet of the double release film to expose the surface of the first adhesive layer; (s) Connecting the exposed surface of the first adhesive layer to the second electrode to form an intermediate electro-optic device; (t) Providing a first light-transmitting electrode; (u) Removing the second release sheet of the intermediate electro-optic device to expose the surface of the second adhesive layer; (v) Connecting the exposed surface of the second adhesive layer to the first light-transmitting electrode. Brief description of the attached diagram

[0051] Various aspects and embodiments of this application will be described with reference to the following figures. It should be understood that the figures are not necessarily drawn to scale.

[0052] Figure 1This is a schematic side view of the electro-optic device of type (B) of the present invention; the device includes a barrier layer located between an electro-optic material layer and a first adhesive layer adjacent to a backplate. The device can be manufactured via a front-panel laminate assembly. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0053] Figure 2 This is a schematic side view of an electro-optic assembly (front panel laminate); it includes a barrier layer located between an electro-optic material layer and a first adhesive layer adjacent to a release liner. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0054] Figure 3 This is a schematic side view of the electro-optic device of type (B) of the present invention; it includes a barrier layer located between an electro-optic material layer and a first adhesive layer adjacent to a backplate. The device can be manufactured via a dual release film having two adhesive layers. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0055] Figure 4 This is a schematic side view of an electro-optic component (dual release film); it includes a barrier layer located between an electro-optic material layer and a first adhesive layer adjacent to a first release sheet. The dual release film has two adhesive layers. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0056] Figure 5 This is a schematic side view of an electro-optic device of type (A) of the present invention; it includes a barrier layer located between an electro-optic material layer and a second adhesive layer, the second adhesive layer being adjacent to a first light-transmitting electrode near the viewing side of the device. The device can be manufactured via a front-panel laminate assembly. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0057] Figure 6 This is a schematic side view of an electro-optic assembly (front panel laminate); it includes a barrier layer located between an electro-optic material layer and a second adhesive layer adjacent to a second release liner. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0058] Figure 7 This is a schematic side view of an electro-optic device of type (A) of the present invention; it includes a barrier layer located between an electro-optic material layer and a second adhesive layer, the second adhesive layer being adjacent to a first light-transmitting electrode near the viewing side of the device. The device can be manufactured via a double release film having two adhesive layers. The electro-optic material layer includes an electrophoretic medium encapsulated in a microcapsule.

[0059] Figure 8 This is a schematic side view of an electro-optic component (dual release film); it includes a barrier layer located between an electro-optic material layer and a second adhesive layer adjacent to a second release film. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0060] Figure 9 This is a schematic side view of the electro-optic device of type (A) of the present invention; it includes a barrier layer located between an electro-optic material layer and a first adhesive layer adjacent to a backplate. The electro-optic material layer includes an electrophoretic medium encapsulated in microcapsules.

[0061] Figure 10 illustrates the following. Figure 1 An example of a method for manufacturing an electro-optical device.

[0062] Figure 11 illustrates the following. Figure 5 An example of a method for manufacturing an electro-optical device.

[0063] Figures 12 and 13 illustrate the following: Figure 3 An example of a method for manufacturing an electro-optical device.

[0064] Figures 14 and 15 illustrate the following: Figure 7 An example of a method for manufacturing an electro-optical device.

[0065] Figure 16 It is the impedance spectrum of the control electro-optic device without the barrier layer.

[0066] Figure 17 It is the electrical impedance spectrum of the electro-optic device of the present invention containing a barrier layer.

[0067] Figure 18 Equivalent circuit elements of a model for analyzing the electrochemical impedance spectroscopy of the control device of the embodiments and the device of the present invention are shown.

[0068] Other aspects, embodiments, and features of the invention will become apparent when considered in conjunction with the accompanying drawings and the following detailed description.

[0069] Detailed description of the invention

[0070] This invention has many different aspects, which will be described below. It should be understood that a single electro-optic device or a component thereof may utilize multiple aspects of this invention.

[0071] The electro-optic device of the present invention can be an electrophoretic display.

[0072] It is helpful to set forth certain definitions before describing the various aspects of the invention.

[0073] The term “transmittance” refers to a layer, such as a barrier layer or an electrode layer, meaning that such a defined layer transmits enough light to allow a viewer to see through the layer to observe changes in the display state of the electrophoretic medium, which are typically visible through the first electrode layer and an adjacent substrate (if present).

[0074] The term "transparent electrode layer" as used is consistent with its conventional meaning in the field of electro-optic displays and in the aforementioned patents and publications, implying a light-transmitting rigid or flexible material. A transparent electrode layer most commonly comprises a single continuous electrode (including conductive material) extending across the entire viewing side of the display. Typically, the surface of the transparent electrode layer visible to the viewer constitutes the viewing surface, through which the viewer views the display, although additional layers may be inserted between the front substrate and the viewing surface. Like the backplate, the front substrate should provide sufficient barrier properties to prevent moisture and other contaminants from penetrating through the viewing side of the display.

[0075] The term "viewing side" or "viewing surface" of an electrophoretic display refers to the side of the display from which the image is displayed and can be viewed by a viewer. A typical electro-optic device has two sides: a viewing side and a back side. However, an electro-optic device can have two viewing sides.

[0076] Unless otherwise specified, the term “conductive” used in this document for materials, layers or seals means “electrically conductive” materials, layers or seals.

[0077] As used herein, the term "backplate" has the same conventional meaning as in the field of electro-optic devices and in the aforementioned patents and publications, implying a rigid or flexible material comprising an electrode layer having one or more electrodes. The backplate may also be equipped with electronics for addressing the display, or such electronics may be disposed in a unit separate from the backplate. In flexible displays, it is highly desirable for the backplate to provide sufficient barrier properties to prevent moisture and other contaminants from intruding through the non-viewing side of the display (which, of course, is typically viewed from the side furthest from the backplate).

[0078] This invention improves the performance and lifespan of electro-optical devices. Examples of such devices are... Figures 1 to 9 As shown in the image.

[0079] Figure 1 This is a schematic side view of an example of the electro-optic device of the present invention, type (B), including a barrier layer. Figure 1 The electro-optic device 100 includes a first light-transmitting electrode layer 101, an electro-optic material layer 102, a barrier layer 103, a first adhesive layer 104, and a second electrode layer 105, wherein the second layer 105 includes a plurality of pixel electrodes. The electro-optic device may also include a first substrate or a support layer. Figure 1(Not shown in the image). A substrate is located near the first transparent electrode layer 101, such that the first transparent electrode layer 101 is disposed between the first substrate and the electro-optic material layer 102. The substrate may be a polymer film or a glass substrate that supports the first transparent electrode layer and protects it from mechanical damage. A barrier layer 103 is adjacent to and in contact with the electro-optic material layer 102. The electro-optic material layer 102 may include an electrophoretic medium encapsulated in a plurality of microcapsules 106. That is, each microcapsule 106 contains one or more types of charged pigment particles in a non-polar liquid. When an electric field is applied via the first transparent electrode and the second electrode layer, the plurality of charged particles can be moved. Each of the plurality of capsules 106 may contain a plurality of first-type charged particles and a plurality of second-type charged particles in a non-polar liquid. Each of the plurality of capsules 106 may also contain a plurality of third-type charged particles and a plurality of fourth-type charged particles in a non-polar liquid. The electro-optic material layer 102 also includes an adhesive 107. Typically, electro-optic material layers are formed from a slurry (or dispersion) containing a capsule and binder in a liquid. Specifically, the slurry is coated onto a layer and cured to form the electro-optic material layer. Curing of the slurry can be achieved by heat or via UV irradiation. An image is generated by applying an electric field through two electrode layers.

[0080] Figure 1 The electro-optical device 100 can be made by Figure 2 The electro-optic component 200 shown is manufactured as follows. This component is a front panel laminate (FPL) and includes a light-transmitting electrode layer 101, an electro-optic material layer 102, a barrier layer 103, a first adhesive layer 104, and a release liner 205. The electro-optic device 200 may also include a first substrate (…). Figure 2 (Not shown in the image). The substrate is located near the first light-transmitting electrode layer 101, such that the first light-transmitting electrode layer 101 is disposed between the first substrate and the electro-optic material layer 102. The first release liner 205 is removed to expose the surface of the adhesive layer 104. A second electrode layer is formed by bonding it to the exposed surface of the first adhesive layer 104. Figure 1 The (B) type electro-optic device 100. The second electrode may be part of a more complex assembly including circuitry and a substrate, often referred to as a backplane.

[0081] In some implementations, the electro-optic device may include more than one adhesive layer, such as Figure 3 The apparatus 300 is illustrated in the diagram. Figure 3 This is a schematic side view of another example of the electro-optical device of the present invention, type (B), including a barrier layer. Figure 3 The electro-optic device 300 includes a first light-transmitting electrode layer 101, a second adhesive layer 308, an electro-optic material layer 102, a barrier layer 103, a first adhesive layer 104, and a second electrode layer 105, wherein the second layer 105 includes a plurality of pixel electrodes. The electro-optic device may also include a first substrate (…). Figure 3 (Not shown in the image). The substrate is located near the first transparent electrode layer 101, such that the first transparent electrode layer 101 is disposed between the first substrate and the electro-optic material layer 102. The barrier layer 103 is adjacent to and in contact with the electro-optic material layer 102. The electro-optic material layer 102 may include an electrophoretic medium encapsulated in a plurality of microcapsules 106. That is, each microcapsule 106 contains one or more types of charged pigment particles in a non-polar liquid. The electro-optic material layer 102 also includes an adhesive 107. The second adhesive layer 308 may contain an adhesive different from the adhesive of the first adhesive layer 104. The second adhesive layer 308 may contain the same adhesive as the adhesive of the first adhesive layer 104. Furthermore, the first adhesive layer 104 may contain a dopant with a first concentration and the second adhesive layer 308 may contain a dopant with a second concentration. The second dopant concentration in the second adhesive layer 308 may be higher than the first dopant concentration in the first adhesive layer 104.

[0082] Figure 3 The electro-optical device 300 can be made by Figure 4 The electro-optic component 400 shown is manufactured. This component is a dual release film (DRF) and includes a second release film 415, a first adhesive layer 308, an electro-optic material layer 102, a barrier layer 103, a first adhesive layer 104, and a first release sheet 205. The first release sheet 205 is removed to expose the surface of the adhesive layer 104. A second electrode layer including a plurality of pixel electrodes is bonded to the exposed surface of the first adhesive layer 104 to form an intermediate electro-optic device. Then, the first release sheet 205 is removed to expose the surface of the second adhesive layer 308. A first light-transmitting electrode is bonded to the exposed surface of the second adhesive layer 304 to form the electro-optic device 300, which... Figure 3 As shown in the image.

[0083] Figure 5 This is a schematic side view of an example of the electro-optic device of the present invention, type (A), including a barrier layer. Figure 5 The electro-optic device 500 includes a first light-transmitting electrode layer 101, a barrier layer 103, an electro-optic material layer 102, a first adhesive layer 104, and a second electrode layer 105, wherein the second layer 105 includes a plurality of pixel electrodes. The electro-optic device may also include a first substrate (…). Figure 5 (Not shown in the image). The substrate is located near the first transparent electrode layer 101, such that the first transparent electrode layer 101 is disposed between the first substrate and the electro-optic material layer 102. The barrier layer 103 is adjacent to and in contact with the electro-optic material layer 102. The electro-optic material layer 102 may include an electrophoretic medium encapsulated in a plurality of microcapsules 106. That is, each microcapsule 106 contains one or more types of charged pigment particles in a non-polar liquid. The electro-optic material layer 102 also includes an adhesive 107.

[0084] Figure 5 The electro-optical device 500 can be made by Figure 6 The electro-optic component 600 shown is manufactured as follows. This component is a front panel laminate (FPL) and includes a light-transmitting electrode layer 101, a barrier layer 103, an electro-optic material layer 102, a first adhesive layer 104, and a release liner 205. The electro-optic component 600 may also include a first substrate (…). Figure 6 (Not shown in the image). The substrate is located near the first light-transmitting electrode layer 101, such that the first light-transmitting electrode layer 101 is disposed between the first substrate and the electro-optic material layer 102. The first release liner 205 is removed to expose the surface of the adhesive layer 104. A second electrode layer including a plurality of pixel electrodes is formed on the exposed surface of the first adhesive layer 104. Figure 5 The electro-optic device 500. The second electrode may be part of a more complex assembly including circuitry and a substrate, often referred to as a backplane.

[0085] Figure 7 This is a schematic side view of another example of the electro-optical device of the present invention, type (A), including a barrier layer. Figure 7 The electro-optic device 700 includes a first light-transmitting electrode layer 101, a second adhesive layer 308, a barrier layer 103, an electro-optic material layer 102, a first adhesive layer 104, and a second electrode layer 105, wherein the second layer 105 includes a plurality of pixel electrodes. The electro-optic device may also include a first substrate (…). Figure 7 (Not shown in the image). The substrate is located near the first transparent electrode layer 101, such that the first transparent electrode layer 101 is disposed between the first substrate and the barrier layer 103. The barrier layer 103 is adjacent to and in contact with the electro-optic material layer 102. The electro-optic material layer 102 may include an electrophoretic medium encapsulated in a plurality of microcapsules 106. That is, each microcapsule 106 contains one or more types of charged pigment particles in a nonpolar liquid. The electro-optic material layer 102 also includes an adhesive 107.

[0086] Figure 7 The electro-optical device 700 can be made by Figure 8 The electro-optic component 800 shown is manufactured. This component is a dual release film (DRF) and includes a second release film 415, a first adhesive layer 308, a barrier layer 103, an electro-optic material layer 102, a first adhesive layer 104, and a first release sheet 205. The first release sheet 205 is removed to expose the surface of the adhesive layer 104. A second electrode layer including a plurality of pixel electrodes is bonded to the exposed surface of the first adhesive layer 104 to form an intermediate electro-optic device. Then, the first release sheet 205 is removed to expose the surface of the second adhesive layer 308. A first light-transmitting electrode is bonded to the exposed surface of the second adhesive layer 304 to form an electro-optic device 700, which... Figure 7 As shown in the image.

[0087] Figure 9This is a schematic side view of another example of the electro-optical device of the present invention, type (A), including a barrier layer. Figure 9 The electro-optic device 900 includes a first light-transmitting electrode layer 101, an electro-optic material layer 902, a first adhesive layer 104, and a second electrode layer 105, wherein the second layer 105 includes a plurality of pixel electrodes. The electro-optic device may also include a first substrate (…). Figure 9 (Not shown in the image). The substrate is located near the first transparent electrode layer 101, such that the first transparent electrode layer 101 is disposed between the first substrate and the electro-optic material layer 902. The barrier layer 103 is adjacent to and in contact with the electro-optic material layer 902. The electro-optic material layer 902 may contain an electrophoretic medium, which is encapsulated in a plurality of microcells 920. Each microcell includes a partition wall 930. Each microcell has an opening sealed by a sealing layer 930. That is, the sealing layer 930 spans the opening of each microcell.

[0088] Figure 10A and Figure 10B An example of a method for manufacturing a (B) type electro-optic device 100 via an electro-optic component 200 (front panel laminate) is outlined. Figure 10A Steps 1 through 4 are outlined in the document, as well as in... Figure 10B Steps 5 through 7 are outlined. In step 1 of the method for manufacturing the electro-optic device 100, a first light-transmitting electrode layer 101 is provided. In step 2, an electro-optic material paste ( Figure 10A (Not shown) is coated onto the surface of the first light-transmitting electrode layer 101. An electro-optic material slurry is cured to form a structure 1010 comprising an electro-optic material layer 102 on the first electro-optically transparent layer 101. The electro-optic material slurry contains a plurality of capsules 106 and an adhesive 107 within a carrier. Each of the multiple capsules contains a plurality of charged particles in a non-polar liquid. Curing of the electro-optic material slurry can be achieved by heating, evaporation, or via UV irradiation.

[0089] In step 3, a barrier layer 103 is formed on the surface of the electro-optic material layer 102 of structure 1010, thereby forming structure 1020, which sequentially includes a first light-transmitting layer 101, an electro-optic material layer 102 and a barrier layer 103.

[0090] In step 4, a first adhesive layer 104 is formed by coating the adhesive composition 114 onto the barrier layer 103, and then the initially formed adhesive coating is cured by heat or by UV irradiation to produce a structure 1030, which includes a first light-transmitting electrode layer 101, an electro-optic material layer 102, a barrier layer 103 and a first adhesive layer 104.

[0091] In step 5 of the method for manufacturing the electro-optic device 100, a release liner is bonded to the adhesive layer 104 of structure 1030 to form an electro-optic assembly 200, which is a front panel laminate (FPL). In step 6, the release liner 205 is removed from the electro-optic assembly 200 to expose the surface of the first adhesive layer 104. In step 7, a second electrode layer 105 is bonded to the first adhesive layer 104 to form the electro-optic device 100. The second electrode layer 105 may be part of a backplate, which may also include circuitry. That is, a backplate including the second electrode layer 105 can be used in step 7 of the method for manufacturing the electro-optic device 100.

[0092] Figure 11A and Figure 11B An example of a method for manufacturing a (A) type electro-optic device 500 via an electro-optic component 600 (front panel laminate) is outlined. Figure 11A Steps 1 through 4 are outlined in the document, as well as in... Figure 11B Steps 5 through 7 are outlined. In step 1 of the method for manufacturing the electro-optic device 400, a first light-transmitting electrode layer 101 is provided. In step 2, a barrier layer 103 is formed on the first light-transmitting layer 101 to form a structure 1110. In step 3, an electro-optic material paste ( Figure 11A (Not shown) is coated onto the barrier layer 103 of structure 1110. The electro-optic material paste is cured to form structure 1120 including electro-optic material layer 102, barrier layer 103, and first light-transmitting layer 101. The electro-optic material paste contains multiple capsules 106 and adhesive 107 in a carrier. Curing of the electro-optic material paste can be achieved by heating, evaporation, or via UV irradiation.

[0093] In step 4, a first adhesive layer 104 is formed by coating the adhesive composition 114 onto the electro-optic material layer 102 of structure 1120, and then the initially formed adhesive coating is cured by heat or by UV irradiation to produce structure 1130, which includes a first light-transmitting electrode layer 101, a barrier layer 103, an electro-optic material layer 102 and a first adhesive layer 104.

[0094] In step 5 of the method for manufacturing the electro-optic device 500, a release liner is bonded to the adhesive layer 104 of structure 1130 to form an electro-optic assembly 600, which is a front panel laminate (FPL). In step 6, the release liner 205 is removed from the electro-optic assembly 600 to expose the surface of the first adhesive layer 104. In step 7, a second electrode layer 105 is bonded to the first adhesive layer 104 to form the electro-optic device 500. The second electrode layer 105 may be part of a backplate, which may also include circuitry. That is, a backplate including the second electrode layer 105 can be used in step 7 of the method for manufacturing the electro-optic device 500.

[0095] Figure 12A, 12B 12C, 12D, 13A and Figure 13B An example of a method for manufacturing a (B) type electro-optic device 300 via an electro-optic component 400, which is a dual release film (DRF), is outlined. Figure 12A , 12B Examples of manufacturing methods for electro-optical component 400 (double release film) are outlined in 12C and 12D. Figure 12A and 12B The method for manufacturing an electro-optic device 300 starting from an electro-optic component 400 is outlined. Figure 12A Steps 1 to 3 are outlined. Figure 12B Steps 4 through 6 are outlined. Figure 12C Step 7 is outlined. Figure 12D Steps 8 through 10 are outlined. Figure 13A Step 11 is outlined. Figure 13B Step 12 is outlined.

[0096] In step 1 of the manufacturing method of the electro-optic device 300, a third release sheet 1235 is provided. In step 2, the electro-optic material paste ( Figure 12A (Not shown) is coated onto the surface of the third release film 1235 to form structure 1210. In step 3, a barrier layer 103 is formed on the electro-optic material layer 102 of structure 1210 to form electro-optic material layer 1220, which sequentially includes the third release film 1235, electro-optic material layer 102 and barrier layer 103.

[0097] In step 4, a first release sheet 405 is provided. A first adhesive composition 114 is coated onto the first release sheet 405. In step 5, the coating is cured onto the first release sheet 405 to form a first adhesive layer 104. In step 6, a fourth release sheet 1245 is bonded to the first adhesive layer 104 to form a first release assembly 1230.

[0098] In step 7, the fourth release sheet 1245 is removed from the first release assembly 1230, exposing the surface of the first adhesive layer 104, and the surface is attached to the barrier layer 103 of the electro-optic material film 1220 to form the intermediate electro-optic assembly 1240.

[0099] In step 8, a second release film 415 is provided. In step 9, a second adhesive composition 1218 is coated and cured on the surface of the second release film 415 to form a second adhesive layer 308 (structure 1250) on the second release film 415.

[0100] In step 10, the third release liner of the intermediate electro-optic component 1240 is removed, exposing the surface of the electro-optic material layer 102. The exposed surface of the electro-optic material layer 102 is then attached to the second adhesive layer 308 of the structure 1250 to form a double release film 400, which sequentially includes a second release liner 415, a second adhesive layer 308, an electro-optic material layer 102, a barrier layer 102, a first adhesive layer 104, and a first release liner 405.

[0101] In step 11, the first release sheet of the dual release film 400 is removed, exposing the surface of the first adhesive layer 104. The exposed surface of the first adhesive layer is then connected to the second electrode layer 105, which includes a plurality of pixel electrodes to form an intermediate electro-optic device 1310.

[0102] Finally, in step 12, the second release liner 415 is removed from the intermediate electro-optic device 1310, exposing the surface of the second adhesive layer 308. The exposed surface of the second adhesive layer 308 is then connected to the first light-transmitting electrode 101 to form the electro-optic device 300.

[0103] Figure 14A , 14B 14C, 14D, 15A and 15B outline examples of methods for manufacturing a (A) type electro-optic device 700 via an electro-optic component 800, which is a dual release film (DRF). Figure 14A , 14B 14C and 14D outline examples of methods for manufacturing electro-optical component 800 (double release film). Figure 15A and 15B The method for manufacturing an electro-optic device 700 starting from an electro-optic component 800 is outlined. Figure 14A Steps 1 to 3 are outlined. Figure 14B Steps 4 through 6 are outlined. Figure 14C Step 7 is outlined. Figure 14D Steps 8 through 10 are outlined. Figure 15A Step 11 is outlined. Figure 15B Step 12 is outlined.

[0104] In step 1 of the manufacturing method of the electro-optic device 700, a third release sheet 1235 is provided. In step 2, the electro-optic material paste ( Figure 12A (Not shown) is coated onto the surface of the third release film 1235 to form structure 1210. In step 3, a barrier layer 103 is formed on the electro-optic material layer 102 of structure 1210 to form an electro-optic material film 1220, which sequentially includes the third release film 1235, the electro-optic material layer 102 and the barrier layer 103.

[0105] In step 4, a second release film 415 is provided. A second adhesive composition 1218 is coated onto the second release film 415. In step 5, the coating is cured onto the second release film 415 to form a second adhesive layer 308. In step 6, a fourth release film 1245 is bonded to the second adhesive layer 308 to form a second release structure 1430.

[0106] In step 7, the fourth release sheet 1245 is removed from the second release structure 1430, exposing the surface of the second adhesive layer 308, and the surface is attached to the barrier layer 103 of the electro-optic material film 1220 to form the intermediate electro-optic structure 1440.

[0107] In step 8, a first release film 405 is provided. In step 9, a second adhesive composition 114 is coated and cured on the surface of the first release film 405 to form a first adhesive layer 104 (structure 1450) on the first release film 405.

[0108] In step 10, the third release liner of the intermediate electro-optic structure 1440 is removed, exposing the surface of the electro-optic material layer 102. The exposed surface of the electro-optic material layer 102 is then attached to the first adhesive layer 104 of the structure 1450 to form a double release liner 800, which sequentially includes a second release liner 415, a second adhesive layer 308, a barrier layer 103, the electro-optic material layer 102, the first adhesive layer 104, and the first release liner 405.

[0109] In step 11, the first release liner of the dual release liner 800 is removed, exposing the surface of the first adhesive layer 104. The exposed surface of the first adhesive layer is connected to the second electrode layer 105 to form an intermediate electro-optical field 1510, the second electrode layer 105 including a plurality of pixel electrodes.

[0110] Finally, in step 12, the second release sheet 415 is removed from the intermediate electro-optical patch 1510, exposing the surface of the second adhesive layer 308. The exposed surface of the second adhesive layer 308 is then connected to the first light-transmitting electrode 101 to form the electro-optical device 700.

[0111] Adhesive compositions for laminated structures are generally known. They are used to bond different layers of a laminated structure together. Such adhesive compositions may contain, for example, hot-melt adhesives and / or wet-apply adhesives, such as polyurethane-based adhesives. Typically, electro-optical components are laminated structures and include adhesive layers. The adhesive layers of an electro-optical component must meet certain requirements related to its mechanical, thermal, and electrical properties.

[0112] There are certain issues with the selection of laminating adhesives for electro-optic displays. Because laminating adhesives are typically located between electrodes that apply the electric field required to change the electrical state of the electro-optic medium, the conductivity of the adhesive can significantly affect the electro-optic performance of the display.

[0113] The volume resistivity of the laminating adhesive affects the total voltage drop across the electro-optic medium, a key factor influencing the medium's performance. The voltage drop across the electro-optic medium equals the voltage drop across the electrodes minus the voltage drop across the laminating adhesive. On one hand, if the adhesive layer's resistivity is too high, a significant voltage drop occurs within the adhesive layer, requiring a higher voltage between the electrodes to generate the operating voltage drop at the electro-optic medium. Increasing the voltage across the electrodes in this way is undesirable because it increases power consumption and may require more complex and expensive control circuitry to generate and switch the increased voltage. On the other hand, if the adhesive layer's resistivity is too low, undesirable crosstalk exists between adjacent electrodes (i.e., active matrix electrodes), or the device may short-circuit directly. Moreover, because the volume resistivity of most materials decreases rapidly with increasing temperature, if the adhesive's volume resistivity is too low, the display's performance will vary significantly with temperatures significantly above (or below) room temperature.

[0114] For these reasons, there is an optimal range of resistivity values ​​for laminated adhesives used in most electro-optic media, which varies with the resistivity of the electro-optic medium. The volume resistivity of the encapsulated electrophoretic medium is typically around 10⁻⁶. 10 The resistivity of the laminated adhesive is typically on the same order of magnitude as that of other electro-optic media, such as Ω·cm. Therefore, for good electro-optic performance, the volume resistivity of the laminated adhesive is preferably around 10 Ω·cm at the display's operating temperature of approximately 20°C. 8 Ω·cm to approximately 10 12 Ω·cm, or approximately 10 9 Ω·cm to approximately 10 11 Within the range of Ω·cm. Preferably, the volume resistivity of the laminated adhesive also changes with temperature, similar to that of the electro-optic dielectric itself. The values ​​correspond to measurements taken after one week of adaptation at 25°C and 50% relative humidity.

[0115] One method to improve the electro-optic performance of electro-optic devices is to add ionic dopants, such as inorganic or organic salts, including ionic liquids, to the adhesive composition. For example, to improve the performance of commercially available polyurethane adhesive compositions, the composition may be doped with salts or other materials. Non-limiting examples of such dopants are tetrabutylammonium hexafluorophosphate, butylmethylimidazolium hexafluorophosphate, and other ionic liquids.

[0116] Examples of commercial electro-optic devices include those comprising two adhesive layers. A typical example is a display comprising a first electrode layer, a second adhesive layer, an electro-optic material layer, and a second electrode layer. The dopant concentration in the second adhesive layer is typically higher than that in the first adhesive layer. Due to the proximity of the first adhesive layer to the pixel electrode, the high conductivity of the first adhesive layer negatively impacts display resolution by increasing haloing. However, dopant molecules can diffuse from the second adhesive layer through various layers of the display to the first adhesive layer, degrading image quality. The presence of a barrier layer in the device of the present invention, adjacent to the electro-optic material, prevents such dopant diffusion and improves image quality. Furthermore, in the absence of a barrier layer, dopant and other small molecules can diffuse toward the pixel electrodes and components of the device's circuitry, degrading these components and reducing the device's lifespan.

[0117] In one embodiment of the present invention (type (A) electro-optic device), a barrier layer is located between the first transparent electrode layer and the electro-optic material layer. In such a device, the barrier layer must be transparent. In this case, the ability to construct a barrier layer with a small average thickness is critical. Sputtering or vapor deposition methods can meet this criterion.

[0118] Barrier layers can be formed via room-temperature radio frequency (RF) sputtering. This method deposits the material used in the barrier layer onto a desired surface. The advantages of this method lie in its flexibility in optimizing surface morphology and roughness, as well as its ability to form ultrathin barrier layers. Method parameters, such as RF power, sputtering pressure, and material composition, can be varied to achieve the desired thickness and uniformity.

[0119] The barrier layer of the present invention can be formed using materials selected from metal oxides, metal nitrides, metals, and combinations thereof. Non-limiting examples of metal oxides include silicon dioxide, aluminum oxide, titanium oxide, and indium-tungsten oxide. Non-limiting examples of metal nitrides include aluminum nitride, titanium nitride, and silicon nitride. Non-limiting examples of metals include iron, titanium, germanium, vanadium, tungsten, silicon, silver, nickel, niobium, chromium, gold, and mixtures thereof.

[0120] The light-transmitting barrier layer can have an average thickness of 5 nm to 200 nm, 10 nm to 100 nm, or 10 nm to 50 nm. In particular, in the case of a light-transmitting barrier layer containing metal, the barrier layer can have an average thickness of 5 nm to 30 nm or 10 nm to 30 nm.

[0121] In another embodiment of the invention (type (B) electro-optic device), a barrier layer is located between the second electrode layer and the electro-optic material layer. In such a device, the barrier layer need not be transparent, but a thin layer is preferred so that the device can be operated without significantly increasing the potential. In this case, the barrier layer may have an average thickness of 5 nm to 1 μm, 8 nm to 500 nm, 10 nm to 150 nm, 12 nm to 100 nm, or 12 nm to 50 nm.

[0122] These and other aspects of the invention will be further understood by considering the following embodiments, which are intended to illustrate certain specific implementations of the invention but are not intended to limit its scope as defined in the claims. Example

[0123] A control device excluding a barrier layer and the device of the present invention including a silica barrier layer were prepared and evaluated. Specifically, a control device comprising a first transparent electrode layer, an electro-optic material layer, and a second electrode layer was prepared. The first transparent electrode layer comprises polyethylene terephthalate (PET) and indium tin oxide (ITO). The electro-optic material layer comprises multiple microcapsules in an adhesive. The second electrode layer comprises indium tin oxide (ITO).

[0124] Another device similar to the control device was also constructed, but a silicon dioxide layer was disposed between the first light-transmitting electrode layer and the electro-optic material layer.

[0125] Embodiment 1 of the present invention

[0126] Fabrication of the device of the present invention: An electro-optic material slurry was coated onto a first transparent (PET / ITO) electrode and partially dried at 55°C for 10 minutes. The electro-optic material slurry comprised (a) microcapsules and a polyurethane binder, the microcapsules containing white and black pigment particles with opposite charges in a hydrocarbon liquid. The assembly was further dried at 25°C for 48 hours. After drying, silicon dioxide was deposited onto the electro-optic material layer by RF sputtering in a vacuum to form a silicon dioxide barrier layer with an average thickness of 10 nm. Finally, indium tin oxide was sputtered (via RF sputtering) onto the silicon dioxide barrier layer to form a second electrode layer of 100 nm.

[0127] Comparative Example 2

[0128] The preparation of the control device is similar to that in Example 1, but without the step of depositing a barrier layer.

[0129] The electrodes of the device in Example 1 were connected to a voltage source, and its conductivity was measured by electrochemical impedance spectroscopy (EIS) at various temperatures using a Solatron instrument (1296 / SI1260). The measurement process was repeated for the device in Example 2 (comparative). The electrochemical impedance spectra of both devices were analyzed using equivalent circuit elements and the corresponding Nyquist model. The Nyquist curves were obtained at... Figure 16 (From the control device of Comparative Example 2) and Figure 17 (The apparatus of the present invention from Example 2) is shown. Figure 17 The equivalent circuit elements for analysis are provided below, where R is the resistance, and Q and α are the parameters of the constant phase elements in Nyquist model equations 1 to 4.

[0130] Model equations

[0131]

[0132] Z in Equation 1 tot The total electrical impedance of the sample is represented by . A set of subcircuit parameters is fitted by minimizing the error function S (from Equation 2). Equation 3 represents the measured dataset, where Z(ω) is the calculated fitted response. Equation 4 represents the calculated response. The ionic conductivity (σ) of the sample is calculated from Equation 4, where R is the bulk resistance of the material, l is the thickness of the material through which the current flows, and A is the cross-sectional area of ​​the test sample material.

[0133] The model identifies two distinct paths through which current propagates across the sample. These two mechanisms are... Figure 16 and Figure 17 Regions A and B in the figure are represented. The calculated conductivity of the two devices at different temperatures is provided in Tables 1 and 2 below.

[0134] Table 1 The conductivity of regions A and B of the device in Example 2 (comparison) at different temperatures.

[0135]

[0136] Table 2 The conductivity of regions A and B of the device in Example 1 (of the present invention) at different temperatures.

[0137]

[0138] The data in Tables 1 and 2 show that the device of Example 1 (the present invention) has a generally low conductivity and a non-diffusion control region on its Nyquist curve.

[0139] The electro-optical performance of the two devices was evaluated by applying a square wave with an amplitude of 30 V and a pulse period of 250 microseconds for 50 seconds. During the waveform application, the state of the color display was determined by measuring the brightness of the state (L*). Table 3 shows the white and black states at the end of the waveform application.

[0140] Table 3. Electro-optical performance of the devices in Examples 1 and 2.

[0141]

[0142] The data in Table 3 confirm that the device of the present invention (Example 1) exhibits better whiteness (higher L*) at all temperatures, but especially at low temperatures.

[0143] Furthermore, during the application of the square wave, the white-state brightness (L*) fluctuation, which serves as the difference between the white-state baseline and the white-state peak, was measured. It was found that the average white-state brightness fluctuation of the device in Example 2 (Comparative) was 8 L* units, while the average white-state brightness fluctuation of the device in Example 1 (Invention) was 2 L*. This means that the "flickering" of the device is much more pronounced in the comparative device during transitions between different states. In other words, the device of the present invention performs significantly better in terms of flickering.

[0144] The value reported by the colorimeter is the reflectance value L*. L* reflects the optical switching performance of the electro-optic device in terms of its effectiveness (where L* adopts the commonly used CIE definition):

[0145] L*=116(R / R0) 1 / 3 -16,

[0146] Where R is reflectance, and R0 is the standard reflectance value.

Claims

1. An electro-optical device, which is a type (A) or (B) electro-optical device, The (A) type electro-optic device comprises, in sequence: First transparent electrode layer; A barrier layer, wherein the barrier layer is transparent to light; Electro-optic material layer; First adhesive layer; and Second electrode layer; The (B) type electro-optical device comprises, in sequence: First transparent electrode layer; Electro-optic material layer; Barrier layer; First adhesive layer; and Second electrode layer; The electro-optic material layer includes an electrophoretic medium containing charged pigment particles in a non-polar liquid, the first adhesive layer contains a first dopant having a first concentration, and the second electrode layer includes a plurality of pixel electrodes.

2. The electro-optical device according to claim 1, wherein, The electrophoretic medium is encapsulated in multiple microcapsules or multiple microunits, each microunit including a partition wall, an opening and a sealing layer, the sealing layer spanning the opening of each microunit.

3. The electro-optical device according to claim 1 or claim 2, wherein, The electrophoretic medium is encapsulated in multiple microcapsules, and the electro-optic device further includes a second adhesive layer disposed between the first electrode layer and the barrier layer in the (A) type electro-optic device, or the second adhesive layer disposed between the barrier layer and the second electrode layer in the (B) type electro-optic device, the second adhesive layer containing a second dopant having a second concentration.

4. The electro-optical device according to claim 3, wherein, The first dopant may be the same as or different from the second dopant.

5. The electro-optical device according to any one of claims 1 to 4, wherein, The first concentration of the first dopant in the first adhesive layer is 50 to 1000 ppm by weight of the first adhesive layer.

6. The electro-optical device according to any one of claims 3 to 5, wherein, The first concentration of the first dopant in the first adhesive layer is lower than the second concentration of the second dopant in the second adhesive layer.

7. The electro-optical device according to any one of claims 3 to 6, wherein, The second concentration of the second dopant in the second adhesive layer is 1,000 to 5,000 ppm based on the weight of the first adhesive layer.

8. The electro-optical device according to any one of claims 1 to 7, wherein, The first dopant is an ionic liquid.

9. The electro-optical device according to any one of claims 3 to 8, wherein, The second dopant is an ionic liquid.

10. The electro-optical device according to any one of claims 1 to 9, wherein, The first adhesive layer comprises polyurethane.

11. The electro-optical device according to any one of claims 3 to 10, wherein, The second adhesive layer comprises polyurethane.

12. The electro-optical device according to any one of claims 1 to 11, wherein, The barrier layer comprises a material selected from silicon dioxide, aluminum oxide, aluminum nitride, titanium nitride, titanium oxide, silicon nitride, indium tungsten oxide, metals, and mixtures thereof.

13. The electro-optical device of claim 12, wherein, The metal is iron, titanium, germanium, vanadium, tungsten, silicon, silver, nickel, niobium, chromium, gold, and mixtures thereof.

14. The electro-optical device of claim 13, wherein, The average thickness of the barrier layer is 5 to 30 nm.

15. The electro-optical device according to any one of claims 1 to 13, wherein, The average thickness of the barrier layer is 5 nm to 1 micrometer.

16. The electro-optical device according to any one of claims 1 to 13, wherein, The average thickness of the barrier layer is 5 to 200 nm.

17. The electro-optical device according to any one of claims 1 to 16, wherein, The barrier layer is formed by sputtering.

18. The electro-optical device according to any one of claims 1 to 16, wherein, The barrier layer is formed via chemical vapor deposition.

19. A method for manufacturing an electro-optical component, comprising the following steps: A first electrode layer having a surface is provided, the first electrode layer including a light-transmitting electrode; An electro-optic material paste is coated onto the surface of the first electrode layer. The electro-optic material paste comprises multiple microcapsules and an adhesive, each of the multiple microcapsules containing charged particles in a non-polar liquid. The adhesive is cured to form an electro-optic material layer on the first electrode layer; A barrier layer is formed on the electro-optic material by sputtering a barrier material or by chemical vapor deposition of a barrier material; The first adhesive composition is applied to the barrier layer; The adhesive composition is cured to produce a first adhesive layer; The first release sheet is attached to the first adhesive layer.

20. A method for manufacturing an electro-optical device, the method comprising the following steps: Provide a third release film; An electro-optic material paste is coated onto the third release sheet. The paste contains multiple microcapsules and an adhesive, each of the multiple microcapsules containing charged particles in a non-polar liquid. The electro-optic material slurry is cured to form an electro-optic material layer on the third release sheet. An electro-optic material film is formed on the electro-optic material layer by sputtering a barrier material or by chemical vapor deposition of a barrier material, comprising a barrier layer, an electro-optic material layer and a third release film in sequence. Provide a second release sheet; The second adhesive composition is applied onto the second release sheet; The second adhesive composition is cured to produce a second adhesive layer; The fourth release sheet is bonded to the first adhesive layer to form a second release structure, which sequentially includes the fourth release sheet, the second adhesive layer and the second release sheet; Remove the fourth release sheet from the second release structure to expose the surface of the second adhesive layer of the second release structure; The exposed surface of the second adhesive layer is attached to the barrier layer of the electro-optic material film to form an intermediate electro-optic structure, which sequentially includes a second release sheet, a second adhesive layer, a barrier layer, an electro-optic material layer, and a third release sheet. Provide the first release sheet; The first adhesive composition is applied to the first release sheet; The first adhesive composition is cured to produce a first adhesive layer to form a first release structure including the first adhesive layer and the first release sheet; Remove the third release sheet from the intermediate electro-optic structure to expose the surface of the electro-optic material layer; The exposed surface of the electro-optic material layer is attached to the first adhesive layer of the first release structure to form a double release sheet; Provide a second electrode; Remove the first release sheet of the dual release sheet to expose the surface of the first adhesive layer; The exposed surface of the first adhesive layer is connected to the second electrode to form an intermediate electro-optical material; Provide a first light-transmitting electrode layer; Remove the second release sheet of the intermediate electro-optic material to expose the surface of the second adhesive layer; The exposed surface of the second adhesive layer is connected to the first light-transmitting electrode.

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