Electro-optical device comprising an integrated conductive edge seal and method for producing an electro-optical device

Abstract

Improved electro-optic devices are disclosed that include a layer of electrophoretic material that includes an electrophoretic medium disposed between electrodes and a conductive edge seal. The conductive edge seal serves not only to prevent moisture from entering the device, but also to electrically connect the electrodes. An improved method of producing electro-optic devices having a conductive edge seal is also disclosed.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 054,865, filed July 22, 2020, which, together with all other patents and patent applications disclosed herein, are incorporated herein by reference in their entirety. Technical Field

[0003] This invention relates to an electro-optic and related device, and a method for manufacturing the device. The invention is particularly, but exclusively, intended for displays comprising electrophoretic media. The invention can also be used with various other types of solid-state electro-optic media, i.e., those having a solid outer surface, although the media may have an internal cavity containing a fluid (liquid or gas). Therefore, the term "solid-state electro-optic display" includes encapsulated electrophoretic displays, encapsulated liquid crystal displays, and other types of devices. Background Technology

[0004] The term "electro-optic," used here in its conventional sense in the field of imaging, refers to a material having first and second display states, where at least one optical property differs, and the material is changed from its first display state to its second display state by applying an electric field. While the optical property is typically color perceptible to the human eye, it can also be another optical property, such as light transmittance, reflectance, brightness, or, in the case of a display intended for machine reading, a pseudocolor in the sense of a change in reflectance at electromagnetic wavelengths outside the visible light range.

[0005] The term "gray state" is used here in its conventional meaning in the imaging field, referring to a state between the two extreme optical states of a pixel, but not necessarily a black-and-white transition between those two extremes. For example, several patents and publications of IENK, discussed below, describe electrophoretic displays where the extreme states are white and dark blue, making the intermediate "gray state" actually a pale blue. In fact, as already mentioned, a change in optical state may not be a color change at all. The terms "black" and "white" may be used below to refer to the two extreme optical states of a display, and should be understood to generally include extreme optical states that are not strictly black and white, such as the white and dark blue states mentioned above. The term "monochrome" may be used below to refer to a driving scheme that only drives pixels to their two extreme optical states, without an intermediate gray state.

[0006] The terms “bistable” and “bistable” are used herein in their conventional sense in the art, referring to a display comprising display elements having first and second display states, at least one optical characteristic of which differs such that, after any given element is driven to present its first or second display state using an addressing pulse of finite duration, the state will persist for at least several times (e.g., at least four times) the minimum duration of the addressing pulse required to change the state of the display element after the addressing pulse terminates. As shown in U.S. Patent No. 7,170,670, some particle-based electrophoretic displays supporting grayscale are stable not only in their extreme black and white states but also in intermediate gray states, as are some other types of electro-optical displays. This type of display is aptly referred to as “multistable” rather than bistable, but for convenience, the term “bistable” may be used herein to encompass both bistable and multistable displays.

[0007] Several types of electro-optic displays are known. One type of electro-optic display is the rotating bicolor component type, as described in, for example, U.S. Patent 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 component" is preferred as it is more accurate because in some of the patents mentioned above, the rotating component is not spherical). This display uses a number of small bodies (typically spherical or cylindrical) and internal dipoles, each body comprising two or more parts with different optical properties. These bodies are suspended within liquid-filled bubble chambers within a matrix, the bubble chambers being filled with liquid to allow the bodies to rotate freely. The appearance of a display is altered by applying an electric field to the display, thereby rotating the subject to various positions and changing which part of the subject is seen through the viewing surface. This type of electro-optic medium is typically bistable.

[0008] Another type of electro-optic display is the electrowetting display developed by Philips, described in Hayes, RA et al., “Video-Speed ​​Electronic Paper Based on Electrowetting”, Nature, 425, 383-385 (2003). Such an electrowetting display can be fabricated as bistable, as shown in co-pending application sequence No. 10 / 711,802 (Publication No. 2005 / 0151709), filed October 6, 2004.

[0009] Another type of electro-optic display that has been the subject of intensive research and development for many years is the particle-based electrophoretic display, in which multiple charged particles move through a fluid 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, state bistability, and low power consumption. However, long-term image quality issues have hindered their widespread use. For example, the particles constituting an electrophoretic display are prone to settling, resulting in a short lifespan for these displays.

[0010] As mentioned above, the electrophoretic medium requires the presence of a fluid. In most existing electrophoretic media, this fluid is a liquid, but the electrophoretic medium can be generated using a gaseous fluid; see, for example, Kitamura, T. et al., “Electronic toner movement for electronic paper-like display”, IDW Japan, 2001, Paper HCS 1-1, and Yamaguchi, Y. et al., “Toner display using insulative particles charged triboelectrically”, IDW Japan, 2001, Paper AMD4-4). See also U.S. Patent Publication No. 2005 / 0001810; European Patent Applications 1,462,847; 1,482,354; 1,484,635; 1,500,971; 1,501,194; 1,536,271; 1,542,067; 1,577,702; 1,577,703; and 1,598,694; and International Applications WO 2004 / 090626; WO 2004 / 079442; and WO 2004 / 001498. When such gas-based electrophoretic media are used in a direction that allows particle sedimentation, such as in signs where the media are arranged in a vertical plane, these gas-based electrophoretic media are susceptible to the same type of problems as liquid-based electrophoretic media due to the same particle sedimentation. In fact, particle sedimentation is more severe in gas-based electrophoretic media than in liquid-based electrophoretic media because the lower viscosity of gaseous suspensions allows electrophoretic particles to settle more quickly compared to liquids.

[0011] Numerous patents and applications assigned to or in the name of MIT, Einkel Corporation, Einkel California LLC, and related companies describe various techniques for encapsulating micro-unit electrophoresis and other electro-optic media. Encapsulated electrophoretic media comprise a plurality of microcapsules, each microcapsule itself comprising an inner phase and a capsule wall surrounding the inner phase, wherein the inner phase contains electrophoretically movable particles in a fluid medium. Typically, these microcapsules are themselves held in a polymer binder to form a coherent layer located between two electrodes. In micro-unit electrophoretic displays, charged particles and fluid are not encapsulated within microcapsules but are held within multiple cavities formed within a carrier medium (typically a polymer film). Techniques described in these patents and applications include:

[0012] (a) Electrophoretic particles, fluids, and fluid additives; see, for example, U.S. Patent Nos. 7,002,728 and 7,679,814;

[0013] (b) Microcapsules, binders, and encapsulation processes; see, for example, U.S. Patent Nos. 6,922,276 and 7,411,719;

[0014] (c) Microunit structures, wall materials, and methods of forming microunits; see, for example, U.S. Patent Nos. 7,072,095 and 9,279,906;

[0015] (d) Methods for filling and sealing microcells; see, for example, U.S. Patent Nos. 7,144,942 and 7,715,088;

[0016] (e) Films and sub-assemblies comprising electro-optic materials; see, for example, U.S. Patent Nos. 6,982,178 and 7,839,564;

[0017] (f) Backplanes, adhesive layers and other auxiliary layers for use in displays, and methods thereof; see, for example, U.S. Patent Nos. 7,075,703, 7,116,318, 7,535,624, 7,554,712, 7,561,324, 7,649,674, 7,733,554, 8,034,209, 8,610,988 and 9,835,925;

[0018] (g) Color formation and color adjustment; see, for example, U.S. Patent Nos. 7,075,502 and 7,839,564;

[0019] (h) A method for driving a display; see, for example, U.S. Patent Nos. 7,012,600 and 7,453,445;

[0020] (i) Applications of displays; see, for example, U.S. Patent Nos. 7,312,784 and 8,009,348; and

[0021] (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 No. 7,615,325 and U.S. Patent Application Publication Nos. 2015 / 0005720 and 2016 / 0012710.

[0022] 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 so-called polymer-dispersed electrophoretic displays, wherein the electrophoretic medium comprises a plurality of discrete droplets of electrophoretic fluid and a continuous phase of polymeric material, and the discrete droplets of electrophoretic fluid within such a polymer-dispersed electrophoretic display can be considered as capsules or microcapsules, even if no discrete capsule membrane is associated with each individual droplet; see, for example, the aforementioned U.S. Patent No. 6,866,760. Therefore, for the purposes of this application, such polymer-dispersed electrophoretic media are considered a subclass of encapsulated electrophoretic media.

[0023] A related type of electrophoretic display is the so-called "microcell electrophoretic display." In a microcell electrophoretic display, charged particles and fluid are not encapsulated within microcapsules, but rather held within multiple cavities formed within a carrier medium (typically a polymer membrane). See, for example, U.S. Patents Nos. 6,672,921 and 6,788,449, both granted to Sipix Imaging Corporation.

[0024] Encapsulated or micro-cell electrophoretic displays are generally unaffected by the aggregation and sedimentation failure modes of conventional electrophoretic apparatus and offer more beneficial effects, such as the ability to print or coat displays on a variety of flexible and rigid substrates. The term "printing" is used to encompass all forms of printing and coating, including but not limited to: pre-metering coating such as patch die coating, slot or extrusion coating, slide or stack coating, curtain coating; roller coating such as roller blade coating, forward and reverse roller coating; concave coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; screen printing; electrostatic printing; thermal printing; inkjet printing; electrophoretic deposition; and other similar techniques. Therefore, the resulting displays can be flexible. Furthermore, because the display medium can be printed (using various methods), the display itself can be manufactured inexpensively.

[0025] Electro-optic displays typically include an electro-optic material layer and at least two other layers disposed on the opposite side of the electro-optic material layer, one of which is an electrode layer. In most such displays, both layers are electrode layers, and one or both electrode layers are patterned to define pixels of the display. For example, one electrode layer may be patterned as an elongated row electrode, and another as an elongated column electrode extending perpendicularly to the row electrode, with pixels defined by the intersection of the row and column electrodes. Alternatively, more commonly, one electrode layer has the form of a single continuous electrode, and the other electrode layer is patterned as a matrix of pixel electrodes, each pixel electrode matrix defining one pixel of the display. In another type of electro-optic display (which is intended for use with a stylus, printhead, or similar movable electrode separate from the display), only one of the layers adjacent to the electro-optic material layer includes an electrode, and the layer on the opposite side of the electro-optic layer is typically a protective layer designed to prevent damage to the electro-optic material layer by the movable electrode.

[0026] The aforementioned U.S. Patent 6,982,178 also describes a method for forming an electrical connection between a transparent electrode layer and a backplane. As shown in Figures 8 and 9 of U.S. Patent 6,982,178, this connection is achieved by creating a hole through the electro-optic material layer and filling the hole with a conductive material to form a conductive via. From a manufacturing perspective, this method is undesirable because the location of the conductive via is a function of the backplane design; therefore, a precursor assembly with a specific architecture can only be used with one backplane, or a limited range of backplanes. Furthermore, the conductive via method reduces the effective area of ​​the electro-optic material layer, resulting in a reduction in the effective area of ​​the electro-optic device itself.

[0027] Therefore, U.S. Patent 6,982,178 also describes a method for forming the necessary electrical connection by coating the entire area of ​​the FPL with an electro-optic medium and then removing the electro-optic medium to which the electrical connection is to be formed. However, such removal of the electro-optic medium presents its own problems. Typically, the electro-optic medium must be removed by using solvents or mechanical cleaning, both of which can damage or remove the conductive layer of the FPL (which is typically a metal oxide (e.g., indium tin oxide) layer less than 1 micrometer thick), resulting in electrical connection failure. In extreme cases, damage may also be caused to the front substrate (typically a polymer film) used to support and mechanically protect the conductive layer. In some cases, the materials forming the electro-optic medium may not be easily solvated and may not be able to be removed without the use of corrosive solvents and / or high mechanical pressure (either of which would exacerbate the aforementioned problems).

[0028] Therefore, there is a need for an improved method for forming electrical connections between electrodes of electro-optical devices and similar devices, and the present invention attempts to provide such an improved method. Summary of the Invention

[0029] In one aspect, the present invention provides an electro-optic device having an effective display area and comprising: a first light-transmitting electrode layer, an electrophoretic material layer, a back plate including a second electrode layer, and a conductive edge seal. The first light-transmitting electrode layer has an upper surface, a lower surface, and an outer peripheral surface, and includes a first electrode contact position. The upper surface of the first light-transmitting layer has a length and a width. The electrophoretic material layer has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width. The back plate includes the second electrode layer, wherein the second electrode layer includes a second electrode contact position. The back plate has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the back plate has a length and a width. The electrophoretic material layer includes an electrophoretic medium. The upper surface of the electrophoretic material layer contacts the lower surface of the first light-transmitting electrode layer. The lower surface of the electrophoretic material layer contacts the back plate. The conductive edge seal is disposed on the outer peripheral surfaces of the electrophoretic material layer and the first light-transmitting electrode layer. The conductive edge seal is electrically connected to the first light-transmitting electrode at the first electrode contact position and electrically connected to the second electrode layer at the second electrode contact position. At least a portion of the first electrode contact location and at least a portion of the second electrode contact location are outside the volume defined by the vertical extension of the periphery of the upper surface of the electrophoretic material layer. This results in the effective display area of ​​the device being substantially the same as the area of ​​the upper surface of the electrophoretic material layer. The electrophoretic medium may comprise electrophoretic particles in a nonpolar liquid. The electrophoretic medium may be separated into microcapsules or microunits. The conductive edge seal is formed by an edge sealing composition. The edge sealing composition may comprise conductive particles selected from the group consisting of carbon black particles, graphite, carbon nanotubes, metal particles, and mixtures thereof. The edge sealing composition may comprise a conductive polymer. The resistivity of the conductive edge seal may be less than 10 kilohm-cm.

[0030] In another aspect, the present invention provides an electro-optic device having an effective display area and comprising: a first light-transmitting electrode layer, a second adhesive layer, an electrophoretic material layer, a backplate including the second electrode layer, and a conductive edge seal. The first light-transmitting electrode layer has an upper surface, a lower surface, and an outer peripheral surface, and includes a first electrode contact position. The upper surface of the first light-transmitting electrode layer has a length and a width. The first adhesive layer has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the first adhesive layer has a length and a width. The electrophoretic material layer has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width. The second adhesive layer has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the second adhesive layer has a length and a width. The backplate includes the second electrode layer, wherein the second electrode layer includes a second electrode contact position. The backplate has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the backplate has a length and a width. The upper surface of the second adhesive layer contacts the lower surface of the first light-transmitting layer, and the lower surface of the second adhesive layer contacts the upper surface of the electrophoretic material layer. The upper surface of the first adhesive layer contacts the lower surface of the electrophoretic material layer. The lower surface of the first adhesive composition contacts the upper surface of the backing plate. The electrophoretic material layer includes an electrophoretic medium. The length and width of the upper surface of the first transparent electrode layer and the upper surface of the backing plate are greater than the length and width of the perimeter of the upper surface of the electrophoretic material layer, the length and width of the upper surface of the first adhesive layer, and the length and width of the upper surface of the second adhesive layer. The first transparent electrode layer and the backing plate extend outward beyond the perimeter of the upper surface of the electrophoretic material layer and the edges of the first and second adhesive layers, forming a groove. The groove is defined by the outwardly extending outer peripheral surfaces of the first transparent electrode layer, the second adhesive layer, the electrophoretic material layer, the first adhesive layer, and the outwardly extending backing plate. The groove is filled with a conductive edge seal.

[0031] In another aspect, the present invention provides a process for manufacturing an electro-optic device, the process comprising the following steps: (1) providing a sub-assembly comprising (a) an electrophoretic material layer including an electrophoretic medium and having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width, (b) a first adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the first adhesive layer has a length and a width, wherein the upper surface of the first adhesive layer contacts the lower surface of the electrophoretic material layer, (c) a first release sheet disposed on the lower surface of the first adhesive layer, and (d) a second adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the second adhesive layer has a length and a width, wherein the upper surface of the second adhesive layer has a length and a width, wherein the lower ... (e) a second release sheet disposed on the upper surface of the second adhesive layer; (2) removing the first release sheet and contacting the exposed lower surface of the first adhesive layer with a backplate, wherein the backplate includes a second electrode layer, wherein the backplate has an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the backplate has a length and a width, and wherein the upper surface of the backplate contacts the lower surface of the first adhesive layer, wherein the second electrode layer includes a second electrode contact location, wherein at least a portion of the second electrode contact location is outside the volume defined by a vertical extension of the perimeter of the upper surface of the electrophoretic material layer, and wherein the backplate has a length and a width greater than the perimeter of the electrophoretic material layer. (3) Remove the second release sheet and contact the exposed upper surface of the second adhesive layer with the first light-transmitting electrode layer, wherein the first light-transmitting electrode layer includes a first electrode contact location, wherein at least a portion of the first electrode contact location is outside the volume defined by the vertical extension of the perimeter of the perimeter of the upper surface of the electrophoretic material layer, wherein the first light-transmitting electrode layer has an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the first light-transmitting electrode has a length and width greater than the perimeter of the upper surface of the electrophoretic material layer, the length and width of the first adhesive layer, and the length and width of the second adhesive layer. The first transparent electrode layer extends outward beyond the periphery of the upper surface of the electrophoretic material layer and the edges of the first and second adhesive layers, and a groove is formed defined by the outwardly extending first transparent electrode layer, the outer peripheral surface of the first adhesive layer, the outer peripheral surface of the electrophoretic material layer, the outer peripheral surface of the second adhesive layer, and the outwardly extending back plate; (4) disposing of the edge sealing composition in the groove; (5) curing the edge sealing composition to form a conductive edge seal, wherein the conductive edge seal contacts the first transparent electrode layer at the first electrode contact position and contacts the second electrode layer at the second electrode contact position.The peeling force required to remove the second release piece can be lower than the peeling force required to remove the first release piece.

[0032] In another aspect, the present invention provides a process for manufacturing an electro-optic device, comprising the following steps: (1) providing a sub-assembly comprising (a) a first light-transmitting electrode layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the first light-transmitting electrode includes a first electrode contact position; (b) an electrophoretic material layer comprising an electrophoretic medium and having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the electrophoretic material layer contacts the lower surface of the first light-transmitting electrode layer, wherein the upper surface of the electrophoretic material layer is defined by a perimeter, and wherein at least a portion of the first electrode contact position is outside a volume defined by a vertical extension of the perimeter of the upper surface of the electrophoretic material layer; (c) a first adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the first adhesive layer contacts the lower surface of the electrophoretic material layer. (d) a first release sheet, wherein the first release sheet contacts the lower surface of the first adhesive layer; (2) removing the first release sheet and contacting the exposed lower surface of the first adhesive layer with a backing plate, wherein the backing plate includes a second electrode layer, wherein the second electrode layer includes a second electrode contact location, wherein at least a portion of the second electrode contact location is outside the volume defined by a vertical extension of the periphery of the upper surface of the electrophoretic material layer, wherein the backing plate has an upper surface, a lower surface, and an outer peripheral surface, and wherein the lower surface of the first adhesive layer contacts the upper surface of the backing plate; (3) depositing an edge sealing composition around the outer peripheral surface of the first light-transmitting layer, the outer peripheral surface of the electrophoretic dielectric layer, and the outer peripheral surface of the first adhesive layer; (4) curing the edge sealing composition to form a conductive edge seal. Attached Figure Description

[0033] Figure 1A This is a schematic cross-section showing the electro-optic device of the present invention formed using a front-plane laminate.

[0034] Figure 1B This is a schematic cross-section showing the electro-optic device of the present invention formed using a dual release membrane.

[0035] Figure 1C Figures 2 and 2D are schematic cross-sections illustrating the electro-optical device of the present invention, including the groove.

[0036] Figures 1E to 1H This is a three-dimensional schematic diagram of the electro-optic device of the present invention.

[0037] Figures 2A to 2C Figures 3A to 3C are schematic cross-sections illustrating various stages of the process for producing an electro-optical device according to the present invention.

[0038] Figure 4This is a schematic cross-section showing an electro-optic device disclosed in the art, and a corresponding structure of an electro-optic device having a hole including a conductive material.

[0039] Figure 5 This is a top view of the electro-optical device of the present invention, showing the effective display area of ​​the device.

[0040] Figure 6 This is a top view of an electro-optical device with holes including conductive material, showing the display area of ​​the device. Detailed Implementation

[0041] This invention has many different aspects. These aspects will be described primarily individually below, but it should be understood that a single electro-optical device or component thereof may utilize multiple aspects of this invention.

[0042] The electro-optic device of the present invention can be an electrophoretic display.

[0043] It is useful to state certain definitions before describing the various aspects of the invention in detail.

[0044] The term "substantially identical" when referring to two regions being compared means that one region is approximately 97% to approximately 103% of the other region.

[0045] The term "transmittance" means that a specified layer transmits enough light so that an observer can observe changes in the display state of the electrophoretic medium through that layer, which is typically observed through the first electrode layer and the adjacent substrate (if present).

[0046] The term "transparent electrode layer," used in accordance with its conventional meaning in the field of electro-optic displays and in the aforementioned patents and published applications, refers to 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 observer forms the viewing surface through which the observer views the display, although an additional layer 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 entering through the viewing side of the display.

[0047] The term "observation side" or "observation surface" in electrophoresis displays refers to the side of the display on which an image is displayed and can be observed by an observer. Typical electro-optic devices have two sides: an observation side and a back side. However, electro-optic devices can have two observation sides.

[0048] In this article, the term “conductive” as used for materials, layers or seals refers to “conductive” materials, layers or seals.

[0049] The electro-optic device of the present invention includes a first light-transmitting electrode layer. The first light-transmitting electrode layer has an upper surface, a lower surface, and an outer peripheral surface. The upper and lower surfaces are on opposite sides of the first light-transmitting electrode layer. The term "length and width of the first electrode layer" refers to the length and width of the upper surface of the first light-transmitting electrode layer. The first light-transmitting layer includes a first electrode contact position.

[0050] The electrophoretic material layer of the present invention includes an electrophoretic medium. The electrophoretic medium may be separated in microcapsules or in microunits. The electrophoretic material layer has an upper surface, a lower surface, and an outer peripheral surface. The upper surface and the lower surface are on opposite sides of the electrophoretic material layer. The upper surface of the electrophoretic material layer is defined by a perimeter. The perimeter has a length and a width.

[0051] The electro-optic device of the present invention may include a first adhesive layer and / or a second adhesive layer. The first adhesive layer has an upper surface, a lower surface, and an outer peripheral surface. The upper and lower surfaces are on opposite sides of the first adhesive layer. The term "length and width of the first adhesive layer" refers to the length and width dimensions of the upper surface of the first adhesive layer. The second adhesive layer has an upper surface, a lower surface, and an outer peripheral surface. The upper and lower surfaces are on opposite sides of the second adhesive layer. The term "length and width of the second adhesive layer" refers to the length and width dimensions of the upper surface of the second adhesive layer.

[0052] The electro-optic device of the present invention includes a backplate. The backplate includes a second electrode layer. The backplate has an upper surface, a lower surface, and an outer peripheral surface. The upper surface and the lower surface are on opposite sides of the backplate. The term "length and width of the backplate" refers to the length and width of the upper surface of the backplate.

[0053] As used herein, the term "backplane" has the same conventional meaning in the field of electro-optic devices and in the aforementioned patents and published applications, referring to a rigid or flexible material comprising an electrode layer having one or more electrodes. The backplane may also house electronics for addressing the display, or such electronics may be housed in a unit separate from the backplane. In flexible displays, it is highly desirable for the backplane to provide sufficient barrier properties to prevent moisture and other contaminants from entering through the non-viewing side of the display (which is typically viewed from the side furthest from the backplane).

[0054] The term "effective display area" refers to the area of ​​the observation surface of an electrophoretic display capable of displaying variable images. The variable images on an electrophoretic display are generated by applying an electric field to the electrophoretic material layers of the display.

[0055] This invention improves the performance and cost of electro-optic devices and refines their manufacturing method. Examples of such devices are... Figure 1A , 1B As shown in 1D and 5.

[0056] Figure 1A This is a schematic cross-section of an example of an electro-optic device 100 according to the present invention, which can be constructed starting from a front-plane laminate. The electro-optic device 100 includes: a first transparent electrode layer 130, an electrophoretic material layer 122 including encapsulated electrophoretic media, a first adhesive layer 143, a backplate 110 including a second electrode layer, and a conductive edge seal 155. The first transparent electrode layer includes a first electrode contact position 190. The electrophoretic material layer 122 includes an electrophoretic medium separated within microcapsules. Alternatively, the electrophoretic medium may be separated within microcells. The electrophoretic medium may include electrophoretic particles in a nonpolar liquid. The backplate 110 includes the second electrode layer (not included in the image). Figure 1A (shown in the diagram); the second electrode layer includes a second electrode contact position 195. The electrophoretic material layer 122 has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width. Each of the other layers of the electro-optic device (i.e., the first light-transmitting electrode layer 130, the first adhesive layer 143, and the backplate 110) has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the electrophoretic material layer 122 contacts the lower surface of the first light-transmitting electrode layer 130. The lower surface of the electrophoretic material layer 122 contacts the upper surface of the first adhesive layer 143. The lower surface of the first adhesive layer 143 contacts the upper surface of the backplate 110. A conductive edge seal 155 is disposed on the outer peripheral surfaces of the first light-transmitting electrode layer 130, the electrophoretic material layer 122, and the first adhesive layer 143. The conductive edge seal 155 may also be disposed on the outer peripheral surface of the backplate 110 or a portion of the outer peripheral surface of the backplate 110.

[0057] In typical electro-optic devices, edge seals are used to prevent moisture from entering the electrophoretic material. Figure 1A In the device 100, the conductive edge seal 155 is also used to electrically connect the first light-transmitting electrode layer 130 and the second electrode layer of the back plate 110 at the first electrode contact position 190 and the second electrode contact position 195, respectively. At least a portion of the first electrode contact position 190 and at least a portion of the second electrode contact position 195 are outside the volume defined by the vertical extension of the periphery of the upper surface of the electrophoretic material layer 122.

[0058] Figure 1AThe electro-optic device 100 is a three-layer electro-optic display. Its manufacturing process may involve at least one lamination operation. For example, several of the aforementioned Einkel patents and applications describe a process for manufacturing an encapsulated electrophoretic display in which an encapsulated electrophoretic medium comprising microcapsules in an adhesive is coated onto a flexible substrate containing an indium tin oxide (ITO) or similar conductive coating. This conductive coating is a first light-transmitting electrode layer 130. The microcapsule / adhesive coating is dried or cured to form an electro-optic material layer 122, which is firmly bonded to the first light-transmitting layer 130. Separately, a backplate 110 is fabricated comprising a second electrode layer having an array of pixel electrodes and a suitably arranged semiconductor connecting the pixel electrodes to driving circuitry. The substrate having the electrophoretic material layer 122 is laminated onto the backplate 110 using a lamination adhesive of a first adhesive layer 143. A very similar process can be used to fabricate an electrophoretic display that can use a stylus or similar movable electrodes by replacing the backplate with a simple protective layer (such as a plastic film) on which a stylus or other movable electrode can slide. In one form of this process, the backplane itself is flexible and is fabricated by printing pixel electrodes and conductors onto a plastic film or other flexible substrate. The lamination technique used for mass production of displays using this process is roll lamination using lamination adhesives. Similar manufacturing techniques can be used for other types of electro-optic devices. For example, microcell electrophoretic media or rotating dual-color component media can be laminated to the backplane in essentially the same manner as encapsulated electrophoretic media.

[0059] Figure 1A The electro-optic device 100 can be manufactured using a front-plane laminate, which sequentially includes a light-transmitting conductive layer, an electrophoretic material layer, a first adhesive layer, and a release sheet. The light-transmitting layer can be carried on a light-transmitting substrate, which is preferably flexible, in this sense, so that the substrate can be manually wound around, for example, a drum with a diameter of 25 mm without permanent deformation. The substrate is typically a polymer film and will generally have a thickness ranging from about 1 to about 25 mils (25 to 634 micrometers), preferably from about 2 to about 10 mils (51 to 254 micrometers). The light-transmitting conductive layer is conveniently a thin metal layer, such as aluminum or ITO, or it can be a conductive polymer. Polyethylene terephthalate (PET) films coated with aluminum or ITO are commercially available, for example, "Aluminum-coated Mylar" ("Mylar" is a registered trademark) from DuPont, Wilmington, Delaware, and such commercial materials perform well in front-plane laminates.

[0060] Assembly of an electro-optic device using this front-plane laminate can be achieved by removing the release sheet from the front-plane laminate and contacting the first adhesive layer with the backplate under conditions that allow the first adhesive layer to effectively adhere to the backplate, thereby fixing the first adhesive layer, electrophoretic medium, and conductive layer to the backplate. This process is well-suited for mass production because the front-plane laminate can typically be mass-produced using roll-to-roll coating technology and then cut into blocks of any size for a specific backplate. Next, after the edge-sealing composition has dried or cured, the edge-sealing composition is dispensed around the blocks to create a conductive edge seal. The device is typically exposed to a moisture conditioning step at specific temperature and relative humidity prior to edge sealing.

[0061] Figure 1B This is a schematic cross-section of another example of an electro-optic device according to the present invention. The electro-optic device 101 includes: a first light-transmitting electrode layer 131, a second adhesive layer 114, an electrophoretic material layer 123, a first adhesive layer 144, a back plate 111, and a conductive edge seal 156.

[0062] The first transparent electrode layer 131 includes a first electrode contact position 191. The electrophoretic material layer 123 includes an electrophoretic medium separated within microcapsules. The electrophoretic medium may include electrophoretic particles in a nonpolar liquid. The backplate 111 includes a second electrode layer; the second electrode layer includes a second electrode contact position 196. The electrophoretic material layer 123 has an upper surface, a lower surface, and an outer peripheral surface. The upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width. Each of the other layers of the electro-optic device (i.e., the first transparent electrode layer 131, the second adhesive layer 114, the first adhesive layer 144, and the backplate 111) has an upper surface, a lower surface, and an outer peripheral surface.

[0063] The lower surface of the first transparent electrode layer 131 is in contact with the upper surface of the second adhesive layer 114, and the lower surface of the second adhesive layer 114 is in contact with the upper surface of the electrophoretic material layer 123. The lower surface of the electrophoretic material layer 123 is in contact with the upper surface of the first adhesive layer 144. The lower surface of the first adhesive layer 144 is in contact with the upper surface of the backplate 111.

[0064] The conductive edge seal 156 is disposed on the outer peripheral surface of the first light-transmitting electrode layer 131, the second adhesive layer 114, the electrophoretic material layer 123, and the first adhesive layer 144. The conductive edge seal 156 may also be disposed on the outer peripheral surface of the back plate 111 or a portion of the outer peripheral surface of the back plate 111.

[0065] In typical electro-optic devices, edge seals are used to prevent moisture from entering the electrophoretic material. Figure 1BIn the device 101, the conductive edge seal 156 is also used to electrically connect the first light-transmitting electrode layer 131 and the second electrode layer of the back plate 111 at the first electrode contact position 191 and the second electrode contact position 196, respectively. At least a portion of the first electrode contact position 191 and at least a portion of the second electrode contact position 196 are outside the volume defined by the vertical extension of the periphery of the upper surface of the electrophoretic material layer 123.

[0066] Figure 1B The electro-optic device 101 is a four-layer electrophoretic display. Its manufacturing process may involve at least two lamination operations, each beginning with a structure sequentially comprising an electrophoretic material layer sandwiched between two adhesive layers, one or both of which are covered by release sheets (dual release sheets). In the first lamination, the dual release sheets are laminated to a first light-transmitting electrode layer, followed by a second lamination in which the other side of the electrophoretic material layer is laminated to a backing plate to form the electrophoretic display. The order of these two laminations can also be reversed if desired. Figure 1B The electro-optic device can also be constructed starting from a structure comprising, in sequence, a light-transmitting protective layer, a light-transmitting electrode layer, a second adhesive layer, an electrophoretic material, a first adhesive layer, and a release sheet. The release sheet is removed and a backplate is attached to this structure. Subsequently, a conductive edge-sealing composition is dispensed around the electrophoretic material layer and the adhesive layer, and the dispensed composition is dried or cured to produce a conductive edge seal, forming the electro-optic device. The device is typically exposed to a moisture conditioning step at specific temperature and relative humidity prior to edge sealing. Figure 1B The electro-optical device shown can combine good resolution with good low-temperature performance.

[0067] exist Figure 1D A schematic cross-section of another example of an electro-optic device according to the present invention is provided. The electro-optic device 103 includes: a first transparent electrode layer 132, a second adhesive layer 115, an electrophoretic material layer 124 including an encapsulated electrophoretic medium, a first adhesive layer 145, a backplate 112 including the second electrode layer, and a conductive edge seal 157. The conductive edge seal 157 is disposed on the outer peripheral surfaces of the second adhesive layer 115, the electrophoretic material layer 124, and the first adhesive layer 145. Figure 1D The electro-optical device 103 is similar to Figure 1B The electro-optical device 101. With Figure 1B Compared to the electro-optical device 101 (where the length and width of the upper surface of one layer are similar to the length and width of the upper surfaces of the other layers), Figure 1DThe lengths and widths of the upper surfaces of the layers in the electro-optic device 103 are not all the same. Specifically, in the device 103, the lengths and widths of the upper surfaces of the first light-transmitting electrode layer 132 and the back plate 112 are greater than the lengths and widths of the perimeter of the upper surface of the electrophoretic material layer 124, the upper surface of the first adhesive layer 145, and the upper surface of the second adhesive layer 115.

[0068] The first transparent electrode layer 132 and the back plate 112 of device 103 extend outward beyond the periphery of the upper surface of the electrophoretic material layer and the edges of the first and second adhesive layers. This forms a groove defined by the outwardly extending outer peripheral surfaces of the first transparent electrode layer 132, the second adhesive layer 115, the electrophoretic material layer 124, the first adhesive layer 145, and the back plate 112. The formed groove is filled with a conductive edge seal 157. Similar to device 101, the conductive edge seal 157 in device 103 serves not only to prevent moisture from entering the electrophoretic material but also to electrically connect to the first transparent electrode layer 132 and the second electrode layer of the back plate 112 at the first electrode contact position 193 and the second electrode contact position 198, respectively. At least a portion of the first electrode contact position 193 and at least a portion of the second electrode contact position 198 are outside the volume defined by the vertical extension of the periphery of the upper surface of the electrophoretic material layer 124. Figure 1D The electro-optic device is a four-layer electrophoretic display. Figure 1D The precursor of the device is Figure 1C The structure 102 shown has an upper surface of the first light-transmitting electrode layer 132 and the back plate 112 having a length and width greater than the perimeter of the upper surface of the electrophoretic material 124, and the length and width of the upper surfaces of the adhesive layers 115 and 145. The first light-transmitting electrode layer 132 and the back plate 112 extend outward beyond the perimeter of the upper surface of the electrophoretic material layer 124 and the edges of the first and second adhesive layers 115 and 124. Therefore, a groove 141 is formed defined by the outwardly extending outer peripheral surfaces of the first light-transmitting electrode layer 132, the second adhesive layer 115, the electrophoretic material layer 124, the first adhesive layer 145, and the outwardly extending back plate 112. The electro-optic device 103 is completed by dispensing an edge-sealing composition into the groove 141 and drying or curing the edge-sealing composition to form a conductive edge seal 157. The height of the groove can be from about 20 micrometers to about 150 micrometers, and the width can be from about 0.3 millimeters to about 5 millimeters.

[0069] Figure 1E It shows Figure 1B The diagram shows a perspective view of the electro-optic device 101, but it does not show the conductive edge seal. Adjacent layers are... Figure 1EThe layers appear unconnected to each other, only for the purpose of facilitating three-dimensional perspective. The device sequentially includes: a first light-transmitting electrode layer 131, a second adhesive layer 114, an electrophoretic material layer 123, a first adhesive layer 144, and a backplate 111. Figure 1F This is a perspective view of only the electrophoretic material layer 123. Figure 1F The upper surface 171 and the outer peripheral surface 172 of the electrophoretic material layer 123 are shown. The perimeter 175 of the upper surface 171 of the electrophoretic material layer 123 is also shown. The upper surface of the electrophoretic material layer 171 is defined by the perimeter 175. The perimeter 175 of the upper surface 171 of the electrophoretic material layer 123 has a length L and a width W, as shown... Figure 1F As shown.

[0070] Figure 1F The upper surface 171 and the outer peripheral surface 172 of the electrophoretic material layer 123 are shown. The perimeter 175 of the upper surface 171 of the electrophoretic material layer 123 is also shown. The upper surface of the electrophoretic material layer 171 is defined by the perimeter 175. The perimeter 175 of the upper surface 171 of the electrophoretic material layer 123 has a length L and a width W, as shown... Figure 1F As shown.

[0071] Figure 1G and 1H The electro-optical device is shown (also in Figure 1C A perspective view of the precursor 102 (shown in the image). Figure 1G In the middle, adjacent layers in 102 appear unconnected to each other, simply to facilitate three-dimensional perspective of the layers. The device sequentially includes: a first light-transmitting electrode layer 132, a second adhesive layer 115, an electrophoretic material layer 124, a first adhesive layer 145, and a backplate 112.

[0072] The upper surfaces of the first light-transmitting electrode layer 132 and the back plate 112 have a length and width greater than the perimeter of the upper surface of the electrophoretic material 124, and the length and width of the upper surfaces of the adhesive layers 115 and 145. The first light-transmitting electrode layer 132 and the back plate 112 extend outward beyond the edge of the perimeter of the upper surface of the electrophoretic material layer 124 and the edges of the first and second adhesive layers 115 and 124. Therefore, a groove is formed defined by the outwardly extending outer peripheral surfaces of the first light-transmitting electrode layer 132, the second adhesive layer 115, the electrophoretic material layer 124, the first adhesive layer 145, and the outwardly extending back plate 112. Figure 1H As shown, the groove in which the conductive edge sealing composition can be disposed has a height of 186 and a width of 187.

[0073] Figures 2A to 2C Examples of processes for manufacturing the electrophoretic display of the present invention using a dual-release membrane are shown in 3A to 3C. Figure 2AAs shown, the first step involves applying a second adhesive composition 212 onto a second release sheet 211 to form a second adhesive layer 213 on the second release sheet 211. Subsequently, a third release sheet 214 is placed on the second adhesive layer 213 to form a first release roll 210. Figure 2B In the separate sub-process shown, an electrophoretic material composition is coated onto a fourth release sheet 221 to form a structure 220, which is an electrophoretic material layer 222 on the fourth release sheet 221. After releasing the third release sheet 214 from the first release roll 210 and bringing the exposed second adhesive layer 213 into contact with the electrophoretic material layer 222 of the structure 220, an intermediate electro-optic mesh 230 is formed. Figure 2C As shown, the intermediate electro-optic mesh 230 can be used to form a dual-release film 250. More specifically, a first adhesive composition 242 is applied to a first release sheet 241 to form a second release roll 240. After releasing a fourth release sheet 221 from the intermediate electro-optic mesh 230 and bringing the exposed surface of the electrophoretic material layer 222 into contact with the first adhesive layer 243 of the second release roll 240, the dual-release film 250 is formed. The dual-release film 250 can be used to form an electro-optic device. The dual-release sheet can be stored and subsequently used in the production of electro-optic devices. Figures 3A to 3C An example of the process is shown. For example... Figure 3A As shown, the first release sheet 241 of the dual release film 250 is removed, and the back plate 310 is attached to the exposed surface of the first adhesive layer 243 to form structure 320. The second release sheet 211 is removed from structure 320, and the exposed second adhesive layer 213 is attached to the first light-transmitting electrode layer 330 to form structure 340 having the first light-transmitting electrode layer 331. Figure 3B As shown, the length and width of the backplate 310 can be greater than the corresponding length and width of the electrophoretic material layer 222 and the first and second adhesive layers 243 and 213. Therefore, the backplate 310 can extend outward beyond the perimeter of the upper surface of the electrophoretic material layer 222 and the edges of the first and second adhesive layers 243 and 213. Similarly, the length and width of the first light-transmitting electrode layer 331 can be greater than the perimeter of the upper surface of the electrophoretic material layer 222 and the corresponding length and width of the first and second adhesive layers 243 and 213. Therefore, the first light-transmitting electrode layer 331 can extend outward beyond the perimeter of the upper surface of the electrophoretic material layer 222 and the edges of the first and second adhesive layers 243 and 213. If these conditions are met, a groove 341 is formed in the structure 340, defined by the outwardly extending first light-transmitting electrode layer 331, the outer peripheral surface of the second adhesive layer 213, the outer peripheral surface of the electrophoretic layer 222, the outer peripheral surface of the first adhesive layer 243, and the outwardly extending backplate 310. Figure 3C As shown, the conductive edge sealing composition 350 is placed in the groove 341 and cured into an edge seal 355 to form an electro-optic device 360.

[0074] The electro-optic device of the present invention includes a conductive edge seal that contacts a first transparent electrode layer at a first electrode contact location and a second electrode layer at a second electrode contact location. At least a portion of the first and second electrode contact locations are outside the volume defined by a vertical extension of the periphery of the upper surface of the electrophoretic material layer. The conductive edge seal, electrically connected to the first electrode layer at the first electrode contact location and to the second electrode layer at the second electrode contact location, optimizes the effective display area of ​​the device and makes it substantially the same as the area of ​​the electrophoretic material layer. This... Figure 5 The text appears to be a mix of Chinese characters and symbols, making it difficult to translate accurately. Figure 5 A top view of the electro-optical device according to the present invention is shown. Figure 5 The electro-optic device 360 ​​in the middle corresponds to its cross-section in Figure 3C The electro-optic device provided in this embodiment includes a first transparent electrode layer and a back plate 310 that both extend outward beyond the edge of the electrophoretic material layer. Conductive edge seals 355, disposed in grooves formed by the extensions of the first and second electrode layers, are electrically connected to the first transparent layer at a first electrode contact position (390) and to the second electrode layer at a second electrode contact position (395), respectively. Figure 5 and 6 As shown, the effective display area 560 is substantially the same as the area on the upper surface of the electrophoretic material layer, which is completely different from the effective display area of ​​the electro-optic device with different structures of the present invention.

[0075] Figure 4 This is a schematic cross-section of an electro-optic device according to the prior art. The electro-optic device 470 includes: a first transparent electrode layer 430, a second adhesive layer 213, an electrophoretic material layer 222 including an encapsulated electrophoretic medium, a first adhesive layer 243, a backplate 410 (including the second electrode layer), a non-conductive edge seal 455, and a hole 480. The hole 480 cuts through the electrophoretic material layer and the first and second adhesive layers. The hole is filled with a conductive material, such as a metal, to electrically connect the first transparent electrode layer 430 and the second electrode layer of the backplate 410. The conductive material is connected to the first transparent electrode layer 430 at position 490 and to the second electrode layer of the backplate 410 at position 495. Figure 4An intermediate structure of an example of a process for producing the electro-optic device 470 is also described. The electro-optic device 470 can be fabricated from a double-release film 250 comprising a first release sheet 211, a second adhesive layer 213, an electrophoretic material layer 222, a first adhesive layer 243, and a second release sheet 241. A hole 480 is cut through the double-release film and filled with a conductive material. Release sheets 211 and 241 are sequentially removed, a first light-transmitting electrode layer 430 and a backplate 410 are connected, and a non-conductive edge seal 455 is formed, thus forming the electro-optic device 470. The conductive material in the hole 480 is electrically connected to the first light-transmitting electrode layer at position 490 and to the second electrode layer in the backplate 410 at position 495.

[0076] Figure 6 A top view of the electro-optic device 470 of the present invention according to the prior art is shown, corresponding to its cross-section in... Figure 4 The electro-optical device provided in [the document / company]. Figure 3C and 5 In contrast to the electro-optic device 360 ​​of the present invention, the edge seal of the electro-optic device 470 is non-conductive and does not participate in the electrical connection between the first transparent electrode layer and the second electrode layer. This electrical connection in the electro-optic device 470 is achieved by forming a hole 480 containing conductive material, which is connected to the first transparent electrode layer at position 490 and to the first electrode layer at position 495. This electrical connection using the hole 480 results in an effective display area 660 of the electro-optic device being smaller than the area of ​​the electrophoretic material layer, such as... Figure 6 As shown (within the dashed lines), this is consistent with... Figure 3C and 5 The effective display area of ​​the electro-optic device 360 ​​of the present invention (wherein the effective display area 560 is substantially the same as the area of ​​the electrophoretic material layer 222) is completely different.

[0077] Besides maximizing the effective display area, the structure and manufacturing method of the electro-optic device according to the present invention, as shown above, have other advantages. First, fewer steps are required to manufacture the device of the present invention because it is not necessary to create holes through the electrophoretic material layer and fill them with conductive material (conductive vias). Additionally, a cleaning step for a portion of the light-transmitting electrode layer is not required during the manufacturing of the display using the process according to the present invention. Such a step is typically included in methods for fabricating electro-optic devices using a front-plane laminate. The front-plane laminate comprises an electrophoretic material coated on the light-transmitting electrode layer. A portion of the light-transmitting electrode layer is typically cleaned out from the coated electrophoretic medium to create a clean surface for electrical connections within the electro-optic device. Second, the present invention minimizes the resistive voltage drop across the device, enabling the use of smaller and cheaper thin-film transistors on the backplane, and facilitating the simple evaluation of the quality of the corresponding device and precursor structure.

[0078] The electro-optic device of the present invention may include more than one first contact position between a first transparent electrode layer and a conductive edge seal to reduce voltage drop across the device. The electro-optic device may include two or more, three or more, or five or more first contact positions. Similarly, the electro-optic device of the present invention may include more than one second contact position between a second electrode layer and a conductive edge seal. The electro-optic device may include two or more, three or more, or five or more second contact positions.

[0079] The conductive edge seal of the electro-optic device of the present invention must have sufficient barrier properties to prevent moisture from entering the device, and sufficient conductivity to electrically connect the first and second electrode layers of the device. Therefore, measured at 60°C and 100% relative humidity (RH), according to gravimetric analysis (ASTM E96), the water vapor transmission rate of the conductive edge seal must be less than 0.1 g·m⁻¹. -2 ·sky -1 or less than 0.05 g·m -2 ·sky -1 or less than g·m -2 ·sky -1 When measured using ASTM D257, the resistivity of the edge seal for a film thickness of 2 mils must be less than 50 kΩ·cm, or less than 10 kΩ·cm.

[0080] Edge-sealing compositions may include polymers or combinations of polymers. The drying or curing of the edge-sealing composition forms an edge seal in the apparatus. Non-limiting examples of polymers are polyurethanes, epoxy resins, polydimethylsiloxanes, polyacrylates, polymethacrylates, polycarbonates, polyvinyl chloride, polystyrene-olefin copolymers, polyamides, polyesters, polystyrene, polyethylene, polypropylene, polyisobutylene, polyethylene terephthalate, polyethylene naphthalate, ethylene-vinyl alcohol copolymers, poly(ethylene-co-norbornene), styrene-isobutylene-styrene block copolymers, and mixtures thereof. Edge-sealing compositions may contain conductive fillers, such as metal particles, metal nanoparticles, metal wires, metal nanowires, metal nanofibers, conductive carbon black particles, carbon nanotubes, graphite, and combinations thereof. Edge-sealing compositions may also include conductive polymers. Non-limiting examples of conductive polymers are poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT-PSS), polyacetylene, polyphenylene sulfide, polyphenylene vinylidene, and combinations thereof.

[0081] It will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the present invention described above without departing from the scope of the invention. Therefore, all the contents described above are to be interpreted as illustrative rather than restrictive.

Claims

1. An electro-optical device having an effective display area, comprising: A first light-transmitting electrode layer has an upper surface, a lower surface, and an outer peripheral surface, and includes a first electrode contact position, wherein the upper surface of the first light-transmitting electrode layer has a length and a width. A backplate includes a second electrode layer, wherein the second electrode layer includes a second electrode contact position, wherein the backplate has an upper surface, a lower surface, and an outer peripheral surface, and wherein the upper surface of the backplate has a length and a width. An electrophoretic material layer includes an electrophoretic medium and has an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the electrophoretic material layer is defined by a perimeter having a length and a width, wherein the upper surface of the electrophoretic material layer is in contact with the lower surface of the first light-transmitting electrode layer, and the lower surface of the electrophoretic material layer is in contact with the upper surface of the back plate. as well as A conductive edge seal is disposed on the outer peripheral surface of the electrophoretic material layer and the first light-transmitting electrode layer, wherein the conductive edge seal is electrically connected to the first light-transmitting electrode layer at the first electrode contact position and electrically connected to the second electrode layer at the second electrode contact position. At least a portion of the first electrode contact position and at least a portion of the second electrode contact position are outside the volume defined by the vertical extension of the periphery of the upper surface of the electrophoretic material layer, such that the effective display area of ​​the device is substantially the same as the area of ​​the upper surface of the electrophoretic material layer. The water vapor transmission rate of the conductive edge seal, measured using ASTM E96 at 60°C and 100% relative humidity, is less than [a certain value]. ;as well as The resistivity of the conductive edge seal is less than 10 kilohm-cm.

2. The electro-optic device according to claim 1, wherein the electrophoretic medium comprises electrophoretic particles in a nonpolar liquid.

3. The electro-optic device according to claim 2, wherein the electrophoretic medium is separated in microcapsules.

4. The electro-optic device according to claim 2, wherein the electrophoretic medium is separated in microcells.

5. The electro-optic device according to claim 1, wherein the conductive edge seal is formed of an edge sealing composition comprising a polymer selected from the group consisting of polyurethane, epoxy resin, polydimethylsiloxane, polyacrylate, polymethacrylate, polycarbonate, polyvinyl chloride, polystyrene-olefin copolymer, polyamide, polyester, polystyrene, polyethylene, polypropylene, polyisobutylene, polyethylene terephthalate, polyethylene naphthalate, and mixtures thereof.

6. The electro-optic device according to claim 1, wherein the conductive edge seal is formed of an edge sealing composition comprising conductive particles selected from the group consisting of carbon black particles, graphite, carbon nanotubes, metal particles, and mixtures thereof.

7. The electro-optic device of claim 1, wherein the conductive edge seal is formed of an edge sealing composition comprising a conductive polymer.

8. The electro-optic device according to claim 1, further comprising a first adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the first adhesive layer has a length and a width, wherein the upper surface of the first adhesive layer contacts the lower surface of the electrophoretic material layer, and wherein the lower surface of the first adhesive layer contacts the upper surface of the backplate.

9. The electro-optic device of claim 8 further includes a second adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the second adhesive layer has a length and a width, wherein the upper surface of the second adhesive layer contacts the lower surface of the first light-transmitting electrode layer, and the lower surface of the second adhesive layer contacts the upper surface of the electrophoretic material layer.

10. A process for manufacturing electro-optical devices, comprising the following steps: A sub-assembly is provided, comprising (a) a first light-transmitting electrode layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the first light-transmitting electrode layer includes a first electrode contact position; (b) an electrophoretic material layer including an electrophoretic medium and having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the electrophoretic material layer contacts the lower surface of the first light-transmitting electrode layer, wherein the upper surface of the electrophoretic material layer is defined by a perimeter, and wherein at least a portion of the first electrode contact position is outside a volume defined by a vertical extension of the perimeter of the upper surface of the electrophoretic material layer; (c) a first adhesive layer having an upper surface, a lower surface, and an outer peripheral surface, wherein the upper surface of the first adhesive layer contacts the lower surface of the electrophoretic material layer; and (d) a first release sheet, wherein the first release sheet contacts the lower surface of the first adhesive layer. Remove the first release sheet and contact the exposed lower surface of the first adhesive layer with a backplate, wherein the backplate includes a second electrode layer, wherein the second electrode layer includes a second electrode contact location, wherein at least a portion of the second electrode contact location is outside the volume defined by a vertical extension of the periphery of the upper surface of the electrophoretic material layer, wherein the backplate has an upper surface, a lower surface, and an outer peripheral surface, and wherein the lower surface of the first adhesive layer contacts the upper surface of the backplate. An edge-sealing composition is deposited around the outer peripheral surface of the first light-transmitting electrode layer, the outer peripheral surface of the electrophoretic material layer, and the outer peripheral surface of the first adhesive layer; Curing the edge sealing composition to form a conductive edge seal; The water vapor transmission rate of the conductive edge seal, measured using ASTM E96 at 60°C and 100% relative humidity, is less than [a certain value]. ;as well as The resistivity of the conductive edge seal is less than 10 kilohm-cm.

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