Large-area electro-optic light modulator or display

Abstract

A large area switchable electro-optical modulator or display and method of manufacture are disclosed. The invention relates to a large area light modulator comprising an array of independent light modulation cells sandwiched between two larger light transmissive substrates coated on the inner surfaces of the substrates with a light transmissive electrode layer electrically connected to each cell, which electrical connections do not impair the transparency of the light modulator in the on-state. The large area display includes an array of independent display units. A large-area light-transmissive substrate coated with a light-transmissive electrode layer on the inner surface of the substrate is overlaid on independent display units, electrically connected to each unit, and these electrical connections do not impair the transparency of the display. The light modulator and the display can be easily manufactured using conventional equipment.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480062631.8 (22) Application Date 2024.09.13 (30) Priority Data 63 / 542880 2023.10.06 US (85) PCT International Application Entering National Phase Date 2026.03.27 (86) PCT International Application Application Data PCT / US2024 / 046625 2024.09.13 (87) PCT International Application Publication Data WO2025 / 075769 EN 2025.04.10 (71) Applicant Einker Company Address Massachusetts, USA (72) Inventor S.J. Telford M. Lisschau (74) Patent Agency Beijing Panhua Weiye Intellectual Property Agency Co., Ltd. 11280 Patent Attorney Wang Bo (51) Int.Cl. G02F 1 / 167 (2019.01) G02F 1 / 1676 (2019.01) G02F 1 / 16755 (2019.01) (54) Invention Title: Large-Area Electro-Optical Modulator or Display (57) Abstract: Discloses a large-area switchable electro-optic modulator or display and a method for manufacturing it. The large-area light modulator includes an array of independent light modulation units sandwiched between two large light-transmitting substrates. A light-transmitting electrode layer is coated on the inner surface of the substrates and electrically connected to each unit. These electrical connections do not impair the transparency of the light modulator when it is on. The large-area display includes an array of independent display units. A large-area light-transmitting substrate with a light-transmitting electrode layer coated on the inner surface of the substrate is stacked on the independent display units and electrically connected to each unit. These electrical connections do not impair the transparency of the display. The light modulator and the display can be easily manufactured using conventional equipment.Claims 5 pages, Description 15 pages, Drawings 16 pages, CN 121941954 A 2026.04.28 CN 1 21 94 19 54 A 1. An electro-optic device, comprising: (a) a plurality of electro-optic units arranged side-by-side, each of the electro-optic units comprising: a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on the inner surface of the first light-transmitting substrate; a second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; a second light-transmitting conductive layer electrically contacting the conductive vias of the second light-transmitting substrate on the inner surface of the second light-transmitting substrate; and an electro-optic dielectric layer between and in contact with the first and second light-transmitting conductive layers. (b) A third light-transmitting substrate superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units; (c) A third light-transmitting conductive layer between the third light-transmitting substrate and the plurality of electro-optic units, the third light-transmitting conductive layer being electrically contacted with a conductive via of the first light-transmitting substrate of each of the plurality of electro-optic units; (d) A fourth light-transmitting substrate superimposed on the outer surface of the second light-transmitting substrate of each of the plurality of electro-optic units; and (e) A fourth light-transmitting conductive layer between the fourth light-transmitting substrate and the plurality of electro-optic units, the fourth light-transmitting conductive layer being electrically contacted with a conductive via of the second light-transmitting substrate of each of the plurality of electro-optic units. 2. The apparatus of claim 1, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic dielectric. 3. The apparatus of claim 2, wherein the encapsulated electrophoretic dielectric comprises an electrophoretic dielectric encapsulated in a microcapsule or microcup. 4. The apparatus of any preceding claim, wherein the apparatus is a switchable optical modulator, and wherein the electro-optic medium in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent, and the electro-optic medium switches between a first light-absorbing state and a second light-transmitting state by moving between a dispersed particle state and an aggregated particle state. 5. The apparatus of claim 4, wherein the electro-optic medium layer in each electro-optic unit further comprises a polymer structure having a plurality of microwells, wherein when the electro-optic medium is in the second light-transmitting state, the charged pigment particles are collected in the microwells of the polymer structure, and when the electro-optic medium is in the first light-absorbing state, the charged pigment particles are dispersed in the polymer structure.6. The apparatus according to any one of the preceding claims, wherein a driving voltage is applied between the third and fourth light-transmitting conductive layers, causing the electro-optic medium in each electro-optic unit to switch between the first light-absorbing state and the second light-transmitting state. 7. The apparatus according to any one of the preceding claims, wherein the electro-optic medium in each electro-optic unit is bistable. 8. The apparatus according to any one of the preceding claims, wherein the first, second, third, or fourth light-transmitting substrate comprises a polymer comprising acrylate, methacrylate, vinylbenzene, vinyl ether, urethane, or a polyfunctional epoxy compound. (Claims 1 / 5 pages 2 CN 121941954 A) 9. The apparatus according to any one of the preceding claims, wherein the third or fourth light-transmitting substrate comprises plastic or glass. 10. The apparatus of any preceding claim, wherein the first, second, third, or fourth transparent conductive layer comprises: (a) a material selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene), and combinations thereof; (b) an organic material; (c) a composite material; or (d) a sparse mesh. 11. The apparatus of claim 10, wherein the organic material comprises PEDOT (polyethylenedioxythiophene), the composite material comprises a matrix containing graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation. 12. The apparatus of any preceding claim, wherein conductive vias in the first and second transparent substrates form contact points on the outer surfaces of the first and second transparent substrates, the contact points having an average diameter of at least 0.1 micrometers and at most 100 micrometers. 13. The apparatus of any preceding claim, wherein the contact points have an average diameter of at least 25 micrometers and at most 100 micrometers. 14. The apparatus of any preceding claim, wherein the outer surfaces of the first and second light-transmitting substrates have an average density ranging from at least 10 contact points per square centimeter to at most 1000 contact points per square centimeter. 15. The apparatus of any preceding claim, wherein the conductive via occupies less than 10% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates. 16. The apparatus of any preceding claim, wherein the conductive via occupies less than 1% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates. 17. The apparatus of any preceding claim, wherein the conductive via comprises a through-hole in the first and second light-transmitting substrates, filled with a conductive material or embedded with conductive particles.18. A window comprising the device according to any of the preceding claims. 19. A method of manufacturing an electro-optic device, comprising the steps of: (a) providing a plurality of electro-optic units, each of the electro-optic units comprising: a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on an inner surface of the first light-transmitting substrate; a second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; a second light-transmitting conductive layer electrically contacting the conductive vias of the second light-transmitting substrate on an inner surface of the second light-transmitting substrate; and an electro-optic dielectric layer between and in contact with the first and second light-transmitting conductive layers. (b) The plurality of electro-optic units are arranged in a side-by-side, flat arrangement; and (c) A third light-transmitting substrate covered with a third light-transmitting conductive layer is laminated onto one side of the plurality of electro-optic units, and a fourth light-transmitting substrate covered with a fourth light-transmitting conductive layer is laminated onto the opposite side of the plurality of electro-optic units; wherein the third light-transmitting substrate is superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units, and the third light-transmitting conductive layer is disposed between the third light-transmitting substrate and the plurality of electro-optic units, and the third light-transmitting conductive layer is in electrical contact with the conductive via of the first light-transmitting substrate of each of the plurality of electro-optic units; wherein the fourth light-transmitting substrate is superimposed on the outer surface of the second light-transmitting substrate of each of the plurality of electro-optic units, and the fourth light-transmitting conductive layer is disposed between the fourth light-transmitting substrate and the plurality of electro-optic units, and the fourth light-transmitting conductive layer is in electrical contact with the conductive via of the second light-transmitting substrate of each of the plurality of electro-optic units. 20. The method of claim 19, wherein step (a) comprises: (i) forming a hole in the first light-transmitting substrate and depositing a conductive material on the inner surface of the first light-transmitting substrate to form a first light-transmitting conductive layer and a conductive via; and (ii) forming a hole in the second light-transmitting substrate and depositing a conductive material on the inner surface of the second light-transmitting substrate to form a second light-transmitting conductive layer and a conductive via. 21. The method of claim 20, wherein forming the hole in the first and second light-transmitting substrates comprises laser drilling. 22. The method of claim 20, wherein the conductive material comprises a conductive transparent material dispersed in a UV-curable monomer. 23. The method of claim 19, wherein the third and fourth light-transmitting conductive layers comprise a conductive transparent material dispersed in a UV-curable monomer.24. The method of claim 23, wherein step (c) further comprises irradiating the third and fourth transparent conductive layers to cure the UV-curable monomer. 25. The method of claim 23, wherein the conductive transparent material comprises graphene or carbon nanotubes. 26. The method of any preceding claim, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic dielectric. 27. The method of any preceding claim, wherein the encapsulated electrophoretic dielectric comprises an electrophoretic dielectric encapsulated in a microcapsule or microcup. 28. The method of any preceding claim, wherein the electro-optic device is a switchable optical modulator, and wherein the electro-optic dielectric in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent, and the electro-optic dielectric switches between a first light-absorbing state and a second light-transmitting state by moving between a dispersed particle state and an aggregated particle state. 29. The method of claim 28, wherein the electro-optic dielectric layer in each electro-optic unit further comprises a polymer structure having a plurality of microwells, wherein when the electro-optic dielectric is in the second light-transmitting state, the charged pigment particles are collected in the microwells of the polymer structure, and when the electro-optic dielectric is in the first light-absorbing state, the charged pigment particles are dispersed in the polymer structure. 30. The method of any preceding claim, wherein a driving voltage is applied between the third and fourth light-transmitting conductive layers to cause the electro-optic dielectric in each electro-optic unit to switch between the first light-absorbing state and the second light-transmitting state. 31. The method of any preceding claim, wherein the electro-optic dielectric in each electro-optic unit is bistable. 32. The method of any preceding claim, wherein the first, second, third, or fourth light-transmitting substrate comprises a polymer containing acrylates, methacrylates, vinylbenzene, vinyl ethers, urethanes, or polyfunctional epoxy compounds. 33. The method according to any one of the preceding claims, wherein the third or fourth light-transmitting substrate comprises plastic or glass. 34. The method according to any one of the preceding claims, wherein the first, second, third, or fourth light-transmitting conductive layer comprises: (a) a material selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene), and combinations thereof; (b) an organic material; (c) a composite material; or (d) a sparse mesh.35. The method of claim 34, wherein the organic material comprises PEDOT (polyethylene dioxythiophene), the composite material comprises a matrix containing graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation. 36. The method of any preceding claim, wherein conductive vias in the first and second light-transmitting substrates form contact points on the outer surfaces of the first and second light-transmitting substrates, wherein the contact points have an average diameter of at least 0.1 micrometers to at most 100 micrometers. 37. The method of any preceding claim, wherein the contact points have an average diameter of at least 25 micrometers to at most 100 micrometers. 38. The method of any preceding claim, wherein the outer surfaces of the first and second light-transmitting substrates have an average density of from at least 10 contact points per square centimeter to at most 1000 contact points per square centimeter. 39. The method of any preceding claim, wherein the conductive vias occupy less than 10% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates. 40. The method according to any one of the preceding claims, wherein the conductive via occupies less than 1% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates. 41. The method according to any one of the preceding claims, wherein the conductive via includes through-holes in the first and second light-transmitting substrates that are filled with conductive material or embedded with conductive particles. 42. An electro-optic device, comprising: (a) a plurality of electro-optic units arranged side-by-side, each of the electro-optic units sequentially comprising: a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on an inner surface of the first light-transmitting substrate; an electro-optic dielectric layer contacting the first light-transmitting conductive layer; and a backplate comprising at least one electrode; (b) a second light-transmitting substrate superimposed on an outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units; and (c) a second light-transmitting conductive layer between the second light-transmitting substrate and the plurality of electro-optic units, the second light-transmitting conductive layer being electrically contacting the conductive vias of the first light-transmitting substrate of each of the plurality of electro-optic units. 43. The device of claim 42, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic medium. 44. The device of claim 43, wherein the encapsulated electrophoretic medium comprises an electrophoretic medium encapsulated in a microcapsule or microcup. 45. The apparatus according to any of the preceding claims, wherein the electro-optic medium in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent.Claims 4 / 5 Page 5 CN 121941954 A 46. The apparatus according to any of the preceding claims, wherein the electro-optic medium in each electro-optic unit is bistable. 47. The apparatus according to any of the preceding claims, wherein the first or second light-transmitting substrate comprises a polymer comprising acrylate, methacrylate, vinylbenzene, vinyl ether, urethane, or a polyfunctional epoxy compound. 48. The apparatus according to any of the preceding claims, wherein the second light-transmitting substrate comprises plastic or glass. 49. The apparatus according to any of the preceding claims, wherein the first or second light-transmitting conductive layer comprises: (a) a material selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene), and combinations thereof; (b) an organic material; (c) a composite material; or (d) a sparse mesh. 50. The apparatus of claim 49, wherein the organic material comprises PEDOT (polyethylene dioxythiophene), the composite material comprises a matrix comprising graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation. 51. The apparatus of any preceding claim, wherein conductive vias in the first light-transmitting substrate form contact points on the outer surface of the first light-transmitting substrate, the contact points having an average diameter of at least 0.1 micrometers to at most 100 micrometers. 52. The apparatus of any preceding claim, wherein the contact points have an average diameter of at least 25 micrometers to at most 100 micrometers. 53. The apparatus of any preceding claim, wherein the outer surface of the first light-transmitting substrate has an average density of from at least 10 contact points per square centimeter to at most 1000 contact points per square centimeter. 54. The apparatus of any preceding claim, wherein the conductive vias occupy less than 10% of the surface area of ​​the outer surface of the first light-transmitting substrate. 55. The apparatus of any preceding claim, wherein the conductive vias occupy less than 1% of the surface area of ​​the outer surface of the first light-transmitting substrate. 56. The apparatus according to any of the preceding claims, wherein the conductive via comprises a through-hole in a first light-transmitting substrate, filled with a conductive material or embedded with conductive particles. Claims 5 / 5 Page 6 CN 121941954 A Large-area electro-optic modulator or display

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 542880, filed October 6, 2023, entitled “Large-area electro-optic modulator or display,” which is incorporated herein by reference in its entirety. Technical Field

[0003] This application generally relates to electrophoretic displays and other electro-optic displays, as well as light modulation thin films.Background Art

[0004] Optically modulated thin films modulate the amount of light or other electromagnetic radiation passing through an electrophoretic medium. In some instances, the light will pass through the film completely (i.e., from top to bottom). In other instances, the light may pass through the electrophoretic medium, be reflected / scattered away from the surface, and return through the medium a second time (i.e., from the top surface to the bottom surface and back to the top surface). In other instances, the light will be absorbed by pigment particles located at the viewing surface. In other instances, the selective absorption of light by the pigment particles will produce a rendered image, such as text or a picture. Such thin films can be incorporated into displays, signage, variable transmission windows, mirrors, displays, and similar devices. Typically, the film has an "open" state in which one or more groups of pigment particles are isolated in the sides or micro-wells, etc., so that most of the incident light can pass through the medium; and a "closed" state in which one or more groups of pigment particles are dispersed in the medium to absorb some or all of the incident light.

[0005] For example, U.S. Patent No. 10,067,398 discloses an electrophoretic light attenuator comprising a unit including a first substrate, a second substrate spaced apart from the first substrate, a layer containing electrophoretic ink disposed between the substrates, and a monolayer of closely stacked protrusions extending into the electrophoretic ink and disposed adjacent to the surface of the second substrate. The surfaces of these protrusions define recesses between a plurality of adjacent protrusions. The electrophoretic dielectric layer (ink layer) includes at least one type of charged particles that move between a first extreme light state and a second extreme light state in response to an electric field applied to the unit. In the first extreme light state, the particles are maximally diffused within the unit, thereby being located in the path of light passing through the unit and thus strongly attenuating light transmitted from one substrate to the opposite substrate; in the second extreme light state, the particles are maximally concentrated in the recesses, thereby allowing light to pass through. The total area corresponding to the particles concentrated in the recesses is a fraction of the total surface area.

[0006] Such devices rely at least in part on the shape of their non-planar polymer structure to concentrate absorbing charged particles (e.g., black particles) in the electrophoretic ink in a transparent light state, thereby forming (or exposing) light apertures (i.e., transmission regions) and light barriers (i.e., strong absorption regions). This application also relates to more conventional electrophoretic displays, such as those described in U.S. Patent Nos. 9,921,451 and 9,812,073, which modulate light reflected at the viewing surface by the presence of charged pigment particles.

[0007] For convenience, the term “light” will generally be used herein, but the term should be understood broadly to include electromagnetic radiation at non-visible wavelengths. For example, the invention can be applied to providing windows capable of modulating infrared radiation for controlling temperature inside buildings or vehicles. More specifically, the invention relates to light modulators that use particle-based electrophoretic media to control light modulation.Examples of electrophoretic media that can be incorporated into various embodiments of the present invention include, for example, the electrophoretic media described in U.S. Patent Nos. 10,809,590 and 10,983,410, the contents of which are incorporated herein by reference in their entirety.

[0008] Prior art solutions applicable to the present invention that have polymer structures in fluid or gel layers include U.S. Patent No. 8,508,695 of Vlyte Innovations Ltd., which discloses dispersing fluid microdroplets with a diameter of 1 to 5 micrometers in a continuous polymer matrix solidified in situ onto two substrates to accommodate liquid crystals. Furthermore, U.S. Patent No. 10,809,590 of Einkel discloses microencapsulating and deforming fluid microdroplets to form a monolayer of closely packed polymer shells in a polymer matrix on a substrate, followed by the application of an adhesive layer to bond the encapsulated layer to the substrate. Additionally, European patent application publication EP1264210 from Eindhoven, California, discloses imprinting a microcup structure on a substrate, filling the microcup with a fluid having polymerizable components, polymerizing these components to form a sealing layer on the fluid / microcup surface, and then applying an adhesive layer to bond it to a second substrate. Furthermore, EP2976676 from Vlyte Innovations Ltd. discloses forming a wall structure on a substrate, coating the top of the wall with an adhesive, filling the cavity defined by the wall with a fluid, and polymerizing the adhesive to bond the top of the wall to the opposing substrate. EP3281055 describes a flexible device comprising solid polymer microstructures embedded within its observation area, and these microstructures situated on two substrates. These microstructures interlock (i.e., fix) the substrates of the device together by interlocking along their lengths orthogonal to the substrates. The interlocked microstructures integrate into a wall structure that divides the fluid layer of the device into monolayers of discrete volumes contained within respective cavities. This provides significant structural strength to the device. In the method described, paired microstructures (i.e., convex and concave components) are formed on each substrate, then precisely aligned and press-fitted together, thereby sealing the fluid layer within the cavity.

[0009] For many years, particle-based electrophoretic displays have been the subject of intensive research and development, in which multiple charged particles move through a suspended fluid under the influence of an electric field. Compared to liquid crystal displays, such displays can have advantages such as high brightness and contrast, wide viewing angles, bistable states, and low power consumption.The terms “bistable” and “bistable” are used herein in their conventional meaning in the art to refer to a display comprising display elements having at least one optically distinct first display state and a second display state, such that after any given element is 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 (e.g., at least four times) the shortest 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 capable of supporting grayscale are stable not only in their extreme black and white states but also in their intermediate grayscale states, as are some other types of electro-optical displays. Such a type of display is more suitably referred to as “multistable” than bistable, but for convenience, the term “bistable” may be used herein to encompass both bistable and multistable displays.

[0010] As stated above, the electrophoretic medium requires the presence of a suspending fluid. In most existing electrophoretic media, this suspension fluid is a liquid, but electrophoretic media can also be made using gaseous suspension fluids; 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 European patent applications 1429178, 1462847 and 1482354; and international applications WO 2004 / 090626, WO 2004 / 079442, WO 2004 / 077140, WO 2004 / 059379, WO 2004 / 055586, WO 2004 / 008239, WO 2004 / 006006, WO 2004 / 001498, WO 03 / 091799 and WO 03 / 088495. When such gas-based electrophoretic media are used in a direction that allows particle settling (e.g., in a sign, where the media is in a vertical plane), such media exhibit susceptibility to the same type of problems caused by particle settling as liquid-based electrophoretic media. In fact, particle sedimentation presents a more serious problem in gas-based electrophoresis media compared to liquid-based electrophoresis media because the lower viscosity of gaseous suspensions compared to liquid fluids causes electrophoretic particles to settle more quickly.

[0011] Numerous patents and applications assigned to MIT and Inco, Inco California LLC and related companies or in their name describe various techniques for encapsulation and micro-unit electrophoresis and other electro-optic media. (Page 2 / 15, 8 CN 121941954 A) Encapsulated electrophoretic media comprise numerous small capsules, each capsule itself comprising an inner phase containing electrophoretically mobile particles in a fluid medium and a capsule wall surrounding the inner phase. Typically, the capsules themselves are contained 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 retained in multiple cavities formed within a carrier medium (typically a polymer film). The technologies 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) capsules, adhesives, and encapsulation processes; see, for example, U.S. Patent Nos. 6,922,276 and 7,411,719;

[0014] (c) microcell structures, wall materials, and methods of forming microcells; 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) thin films and subassemblies containing electro-optic materials; see, for example, U.S. Patent Nos. 6,982,178 and 7,839,564;

[0017] (f) Backplates, adhesive layers, and other auxiliary layers used in displays, and methods thereof; see, for example, U.S. Patent Nos. 7,116,318 and 7,535,624;

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

[0019] (h) Methods for driving displays; 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, such as U.S. Patent No. 6,241,921 and U.S. Patent Application Publication No. 2015 / As described in 0277160; and the application of packaging and microcell technologies other than displays; see, for example, 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 a so-called polymer dispersion electrophoretic display, 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 dispersion electrophoretic display can be considered as capsules or microcapsules, even if no discrete capsule membrane is associated with each individual droplet; see, for example, U.S. Patent Application Publication No. 2002 / 0131147. Therefore, for the purposes of this application, such polymer dispersion electrophoretic media are considered a subclass of encapsulated electrophoretic media.

[0023] A related type of electrophoretic display is the so-called “micro-unit electrophoretic display.” In a micro-unit electrophoretic display, charged particles and suspended fluid are not encapsulated in microcapsules, but are retained in a plurality of cavities formed within a carrier medium (typically a polymer film). See, for example, International Patent Application Publication No. WO 02 / 01281 and published U.S. Patent Application Publication No. 2002 / 0075556, both of which have been assigned to SiPix Imaging.

[0024] Electrophoretic media are typically opaque (because, for example, in many electrophoretic media, particles essentially block visible light from passing through the display) and operate in either a light-absorbing or light-reflecting mode. However, electrophoretic devices can also be manufactured to operate in a so-called “shutter mode,” in which one display state is substantially opaque and another display state is substantially transparent. See, for example, the aforementioned U.S. Patent Nos. 6,130,774 and 6,172,798, and U.S. Patent Nos. 5,872,552, 6,144,361, 6,271,823, 6,225,971, and 6,184,856. Dielectrophoretic displays are similar to electrophoretic displays but depend on changes in electric field strength and can operate in a similar mode; see U.S. Patent No. 4,418,346. Other types of electro-optic displays may also be able to operate in shutter mode. In particular, when such a "shutter mode" electrophoretic apparatus is built on a transparent substrate, the light transmission through the apparatus can be adjusted. Specification 3 / 15 pages 9 CN 121941954 A

[0025] Packaged or microcell electrophoretic displays are generally not plagued by the aggregation and sedimentation failure modes of conventional electrophoretic apparatuses and offer further advantages such as the ability to print or coat displays on a variety of flexible and rigid substrates.(The use of the word "printing" is intended 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; roll coating, such as doctor blade roll coating, forward and reverse 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; and other similar techniques.) Therefore, the resulting display can be flexible. Furthermore, since the display medium can be printed (using a variety of methods), the display itself can be manufactured at low cost.

[0026] A potentially important market for electrophoretic media is windows with variable light transmission. As the energy performance of buildings becomes increasingly important, electrophoretic media can be used as a coating on windows, electronically controlling the proportion of incident radiation transmitted through the window by changing the optical state of the electrophoretic media. Effective implementation of such “variable transmission” (“VT”) technology in buildings is expected to provide: (1) reduced unwanted thermal effects during hot weather, thereby reducing the amount of energy required for cooling, the size of air conditioning equipment, and peak power demand; (2) increased use of natural light, thereby reducing the energy used for lighting and peak power demand; and (3) improved occupant comfort by enhancing both thermal and visual comfort. The ratio of polished surfaces to enclosed volumes in vehicles or other vehicles is significantly greater than in typical buildings, and therefore even greater benefits are expected. Specifically, effective implementation of VT technology in vehicles is expected to provide not only the benefits mentioned above, but also the following benefits: (1) improved driving safety; (2) reduced glare; (3) improved mirror performance (by using electro-optic coatings on mirrors); and (4) enhanced ability to use head-up displays. Other potential applications of VT technology include privacy glass and anti-glare devices in electronic devices.

[0027] Many switchable electrophoretic light modulator applications and electrophoretic display applications require large coverage areas. For example, modulators could be used for windows in office buildings with areas of several meters by several meters, or electrophoretic displays could be wide signs with diagonal measurements exceeding 1 meter. One factor limiting the manufacture of such large modulators / displays is the difficulty in fabricating large-area polymer structures for concentrating charged particles in the modulator / display when open. Typically, polymer structures are manufactured using an impression cylinder, which is usually 1 meter or less wide, limiting the size of the final polymer structure that can be formed. While multiple small-area light modulator units can be combined into arrays for large window applications, it is difficult to electrically connect individual units not located at the edges of the array without compromising the optical transparency of the light modulator when open, especially since electrical connections are required on both sides of each unit.Therefore, there is a need for large-area light modulators / displays that can be easily manufactured using conventional equipment without compromising optical transparency.

[0028] A large-area electro-optic device includes a plurality of electro-optic units arranged side-by-side. Each electro-optic unit includes: (i) a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; (ii) a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on the inner surface of the first light-transmitting substrate; (iii) a second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; (iv) a second light-transmitting conductive layer electrically contacting the conductive vias of the second light-transmitting substrate on the inner surface of the second light-transmitting substrate; and (v) an electro-optic dielectric layer between and in contact with the first and second light-transmitting conductive layers. The large-area electro-optic device also includes a third light-transmitting substrate superimposed on the outer surface of the first light-transmitting substrate of each of the multiple electro-optic units. A third light-transmitting conductive layer is disposed between the third light-transmitting substrate and the multiple electro-optic units. (Page 4 / 15, CN 121941954 A) The third light-transmitting conductive layer is in electrical contact with the conductive vias of the first light-transmitting substrate of each of the multiple electro-optic units. A fourth light-transmitting substrate is superimposed on the outer surface of the second light-transmitting substrate of each of the multiple electro-optic units. A fourth light-transmitting conductive layer is disposed between the fourth light-transmitting substrate and the multiple electro-optic units. The fourth light-transmitting conductive layer is in electrical contact with the conductive vias of the second light-transmitting substrate of each of the multiple electro-optic units.

[0029] A method of manufacturing an electro-optic device includes the following steps: (a) providing a plurality of electro-optic units; (b) arranging the plurality of electro-optic units in a side-by-side flat arrangement; and (c) laminating a third light-transmitting substrate covered with a third light-transmitting conductive layer onto one side of the plurality of electro-optic units, and laminating a fourth light-transmitting substrate covered with a fourth light-transmitting conductive layer onto the opposite side of the plurality of electro-optic units. Each electro-optic unit includes: (i) a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; (ii) a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on the inner surface of the first light-transmitting substrate; (iii) a second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; (iv) a second light-transmitting conductive layer electrically contacting the conductive vias of the second light-transmitting substrate on the inner surface of the second light-transmitting substrate; and (v) an electro-optic dielectric layer between and in contact with the first and second light-transmitting conductive layers.A third light-transmitting substrate is superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units, and a third light-transmitting conductive layer is disposed between the third light-transmitting substrate and the plurality of electro-optic units. The third light-transmitting conductive layer is in electrical contact with the conductive vias of the first light-transmitting substrate of each of the plurality of electro-optic units. A fourth light-transmitting substrate is superimposed on the outer surface of the second light-transmitting substrate of each of the plurality of electro-optic units, and a fourth light-transmitting conductive layer is disposed between the fourth light-transmitting substrate and the plurality of electro-optic units. The fourth light-transmitting conductive layer is in electrical contact with the conductive vias of the second light-transmitting substrate of each of the plurality of electro-optic units.

[0030] An electro-optic device includes: a plurality of electro-optic units arranged side by side. Each electro-optic unit sequentially includes: (i) a first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; (ii) a first light-transmitting conductive layer electrically contacting the conductive vias of the first light-transmitting substrate on the inner surface of the first light-transmitting substrate; (iii) an electro-optic dielectric layer contacting the first light-transmitting conductive layer; and (iv) a backplate containing at least one electrode. A second light-transmitting substrate is superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units. The second light-transmitting conductive layer is between the second light-transmitting substrate and the plurality of electro-optic units. The second light-transmitting conductive layer is electrically contacting the conductive vias of the first light-transmitting substrate of each of the plurality of electro-optic units.

[0031] These and other aspects of the invention will become apparent from the following description. Brief Description of the Drawings

[0032] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:

[0033] FIG1 is a simplified diagram illustrating an exemplary switchable electrophoretic modulator unit.

[0034] FIG2A is a perspective view of a portion of an exemplary polymer structure forming the electrophoretic layer portion of the light modulator unit.

[0035] FIG2B is a simplified cross-sectional view of a portion of the light modulator unit, showing the device in the "off" state with charged pigment particles dispersed in the unit of the device and absorbing incident light.

[0036] FIG2C is a simplified cross-sectional view of a portion of the light modulator unit in the "on" state, wherein charged pigment particles are concentrated in micro-wells of the polymer structure of the device.

[0037] FIG3A and 3B are cross-sectional and top views, respectively, of another light modulator unit in the "on" state.

[0038] FIG4 is a simplified exploded view of an exemplary large-area light modulator formed by an array of individual light modulator units according to one or more embodiments. Specification 5 / 15 pages 11 CN 121941954 A

[0039] FIG5 is a simplified cross-sectional view of an exemplary individual light modulator unit according to one or more embodiments.

[0040] FIG6 is a simplified perspective view of an electrophoretic display having a substrate with an array of vias according to the prior art.

[0041] FIG7 is a simplified cross-sectional view of a portion of an exemplary large-area light modulator according to one or more embodiments.

[0042] FIG8A-8C show simplified cross-sectional views illustrating an exemplary process for forming a light-transmitting substrate having a light-transmitting conductive layer for use in a light modulator unit according to one or more embodiments.

[0043] FIG9 is a simplified cross-sectional view illustrating an exemplary process for forming a light modulator unit according to one or more embodiments.

[0044] FIG10 is a simplified exploded view of an exemplary large-area display assembled from an array of individual display units according to one or more embodiments.

[0045] FIG11 is a simplified diagram illustrating an exemplary process for producing a display unit according to one or more embodiments.

[0046] The accompanying drawings depict one or more implementations consistent with the present concept and are by way of example only and not as limitations. Detailed Description

[0047] Various embodiments disclosed herein relate to large-area switchable electro-optic modulators and methods of manufacturing them. The large-area light modulator includes an array of independent light modulation units sandwiched between two large transparent substrates. A transparent electrode layer is coated on the inner surface of the substrates and electrically connected to each unit. These electrical connections do not compromise the transparency of the light modulator in the on state. The light modulator can be easily manufactured using conventional equipment.

[0048] The light modulation device can be incorporated into a light control device. The light modulator, in response to an electrical signal, selectively modulates one or more of light transmittance, light attenuation, color, specular transmittance, specular reflectance, or diffuse reflectance, and switches to provide two or more different light states. In one or more embodiments, a first light state is transparent to visible light and corresponds to the maximum light transmittance—the first extreme (i.e., the "on") state; and a second light state corresponds to the minimum light transmittance—the second extreme (i.e., the "off") state. Of course, intermediate states, referred to as gray levels, are also possible. Furthermore, depending on the pigment loading of the electrophoretic medium, the "off" state may not be completely opaque, and the "on" state may not be completely transparent. Additionally, if the device is configured as a mirror or display, the "on" state can be colored or reflective.

[0049] This device utilizes an electro-optic medium such as electrophoretic ink. The electrophoretic ink contains colored charged particles in a suspended fluid, and the electrophoretic ink contacts the surface of a non-planar polymer structure. These colored charged particles can be any color, including black or white. Preferably, the suspended fluid is transparent, and its refractive index matches the transparent non-planar polymer structure at at least one wavelength (typically 550 nm) in the visible spectrum, and also matches or nearly matches (within 0.01) at other visible wavelengths. Therefore, in the absence of colored charged particles, the refraction of visible light rays (at the matched wavelengths) at the interface between the suspended fluid and the non-planar polymer structure is negligible.

[0050] Furthermore, charged pigment particles can be functionalized by surface polymers to improve state stability. Such pigments are described, for example, in U.S. Patent No. 9,921,451, which is incorporated herein by reference in its entirety. For example, if the charged particles are white, they may be composed of inorganic pigments such as TiO2, ZrO2, ZnO, Al2O3, Sb2O3, BaSO4, PbSO4, or the like. They may also be polymer particles with a high refractive index (>1.5) and a specific size (>100 nm) to exhibit white color, be substantially translucent, or be composite particles engineered to have a desired refractive index. Such particles may include, for example, poly(pentabromophenyl methacrylate), poly(2-vinylnaphthalene), poly(naphthyl methacrylate), poly(α-methylstyrene), poly(N-benzylmethacrylamide), or poly(benzyl methacrylate). Black charged particles may be composed of CI pigment Black 26 or CN 121941954 A 28 (page 6 / 15 of the specification) or similar substances (e.g., manganese ferrite black spinel or copper chromate black spinel) or carbon black. Other colors (neither white nor black) may be composed of organic pigments such as CI pigments PR254, PR122, PR149, PG36, PG58, PG7, PB28, PB15:3, PY83, PY138, PY150, PY155 or PY20. Other examples include Clariant Hostaperm Red D3G 70-EDS, Hostaperm Powder E-EDS, PV Fast Red D3G, Hostaperm Red D3G 70, Hostaperm Blue B2G-EDS, Hostaperm Yellow H4G-EDS, Novoperm Yellow HR-70-EDS, and Hostaperm Green GNX; BASF Irgazine Red L 3630, Cinquasia Red L 4100 HD, and Irgazine Red L 3660 HD; and Sun Chemical Phthalocyanine Blue, Phthalocyanine Green, Diaryl Yellow, or Diaryl AAOT Yellow. Color particles can also be composed of inorganic pigments, such as CI Pigment Blue 28, CI Pigment Green 50, CI Pigment Yellow 227, or similar substances. Based on the desired particle charge polarity and charge level, the surface of charged particles can be modified using known techniques, such as those described in U.S. Patent Nos. 6,822,782, 7,002,728, 9,366,935, and 9,372,380 and U.S. Patent Application Publication No. 201,400,11913, all of which are incorporated herein by reference in their entirety.

[0051] These particles may exhibit a natural charge, or may be explicitly charged using a charge control agent, or may acquire a charge when suspended in a solvent or solvent mixture.Suitable charge control agents are well known in the art; they can be polymeric or nonpolymeric in nature, or ionic or nonionic. Examples of charge control agents include, but are not limited to: Solsperse 17000 (active polymeric dispersant), Solsperse 9000 (active polymeric dispersant), OLOA® 11000 (succinimide ashless dispersant), Unithox 750 (ethoxylate), Span 85 (sorbitan trioleate), Petronate L (sodium sulfonate), Alcolec LV30 (soy lecithin), Petrostep B100 (petroleum sulfonate) or B70 (barium sulfonate), Aerosol OT, polyisobutylene derivatives or poly(ethylene-co-butene) derivatives or the like. In addition to the suspended fluid and charged pigment particles, the internal phase may contain stabilizers, surfactants, and charge control agents. When charged pigment particles are dispersed in a solvent, stabilizing materials can adsorb onto the charged pigment particles. This stabilizing material separates the particles from each other, making the variable transmission medium essentially opaque when the particles are in a dispersed state.

[0052] It is known in the art that the use of surfactants can assist in dispersing charged particles (typically carbon black as described above) in solvents with low dielectric constants. Such surfactants typically contain a polar “head group” and a nonpolar “tail group” that is compatible with or soluble in the solvent. The nonpolar tail group can be a saturated or unsaturated hydrocarbon moiety, or other groups soluble in hydrocarbon solvents (such as poly(dialkylsiloxane)). The polar group can be any polar organic functional group, including ionic materials (such as ammonium salts, sulfonates, or phosphonates), or acidic or basic groups. Particularly preferred head groups are carboxylic acid groups or carboxylic acid groups. In some embodiments, dispersants such as polyisobutylene succinimide and / or sorbitan trioleate and / or 2-n-hexyldecanoic acid are added.

[0053] The dispersion may contain one or more stabilizers. Stabilizers suitable for dispersions made according to various embodiments of the invention include, but are not limited to, polyisobutylene and polystyrene. However, only relatively low concentrations of stabilizer may be required. Low concentrations of stabilizer can help maintain the medium in a closed (opaque) or intermediate state, but in the open state, the size of heterogeneous aggregates of oppositely charged particles can be effectively stabilized even in the absence of stabilizer. For example, dispersions incorporated into various embodiments may contain less than or equal to 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, and 1% of stabilizer based on the weight of the dispersion (the listed amounts preferably increase in order). In some embodiments, the dispersion may be free of stabilizer.

[0054] In various embodiments, the fluid used in the variable transmission medium will generally have a low dielectric constant (preferably less than 10, and ideally less than 3).The fluid is preferably a solvent with low viscosity, relatively high refractive index, low cost, low reactivity, and low vapor pressure / high boiling point. The fluid is preferably transparent and may or may not have optical properties different from the optical properties of at least one set of charged particles in the dispersion, such as color (e.g., red, green, blue, cyan, magenta, yellow, white, and black). Examples of solvents include, but are not limited to, aliphatic hydrocarbons such as heptane, octane, and petroleum distillates (such as Isopar® (ExxonMobil) or Isane® (Total)); terpenes such as limonene (e.g., 1-limonene); and aromatic hydrocarbons such as toluene. A particularly preferred solvent is limonene because it combines a low dielectric constant (2.3) with a relatively high refractive index (1.47). The refractive index of the internal phase can be modified by adding a refractive index matching agent. For example, U.S. Patent No. 7,679,814 describes an electrophoretic medium suitable for a variable transmission device, wherein the fluid surrounding the electrophoretic particles comprises a mixture of partially hydrogenated aromatic hydrocarbons and terpenes, preferably d-limonene and partially hydrogenated terphenyl, commercially available under the brand name Cargille® 5040 from Cargille-Sacher Laboratories (55 Commerce Rd, Cedar Grove NJ 07009). In encapsulation media prepared according to various embodiments of the invention, it is preferable that the refractive index of the encapsulation dispersion is matched as closely as possible to the refractive index of the encapsulation material to reduce haze. In most examples, it is advantageous for the refractive index of the inner phase to be between 1.51 and 1.57 at 550 nm, preferably about 1.54. In embodiments using transparent particles with a refractive index matched to the inner phase, the transparent particles also have a refractive index between 1.51 and 1.57 at 550 nm, preferably about 1.54.

[0055] In one or more embodiments, the encapsulation fluid may comprise one or more non-conjugated olefins, preferably cyclic hydrocarbons. Examples of non-conjugated olefins include, but are not limited to, terpenes (such as limonene), phenylcyclohexane, hexyl benzoate, cyclododecanetriene, 1,5-dimethyltetrahydronaphthalene, partially hydrogenated terphenyl (such as Cargille® 5040), phenylmethylsiloxane oligomers, and combinations thereof. According to some embodiments, the most preferred components for the encapsulation fluid comprise cyclododecanetriene and partially hydrogenated terphenyl.

[0056] In one or more embodiments, the amount of stabilizer included in the encapsulation fluid may be lower than that conventionally used in electrophoretic displays. For comparison, see U.S. Patent No. 7,170,670. Such stabilizers may be high molecular weight free polymers, such as polyisobutylene, polystyrene, or poly(lauryl)methacrylate.Therefore, in some embodiments, the encapsulating fluid (i.e., the dispersion) also contains a stabilizer comprising less than 10% by weight of the dispersion. In some embodiments, the dispersion does not contain a stabilizer. It has been found that by reducing the presence of high molecular weight polymers, haze is improved, making the final product more satisfactory.

[0057] In the first optical state of the embodiment, charged particles, in response to an electric field applied to the electrodes, concentrate within a volume defined by a transparent non-planar polymer structure.

[0058] In some embodiments, the electrophoretic medium is bistable because the medium can maintain the desired optical state without the application of an electric field. For example, when the aperture or barrier of the first optical state is bistable, the power supply can be completely removed after switching (i.e., zero volts between the first and second electrodes), while the aperture or barrier remains unchanged. Similarly, in the second optical state (e.g., light-absorbing or "off" state), the absence of aperture is stable after switching and removing the power supply.

[0059] FIG1 is a simplified diagram illustrating an exemplary switchable electrophoretic light modulator unit 10. As described below, the unit 10 can be arrayed with multiple additional light modulator units 10 to form a large-area light modulator. The unit 10 includes an electrophoretic dielectric layer 12 located between a first light-transmitting substrate 14 and a second light-transmitting substrate 16. The main surfaces of the first light-transmitting substrate 14 and the second light-transmitting substrate 16 are opposite to each other and parallel to each other.

[0060] The first light-transmitting substrate 14 and the second light-transmitting substrate 16 may include polymers containing acrylates, methacrylates, vinylbenzene, vinyl ethers, or multifunctional epoxy compounds.

[0061] A first transparent electrode layer 18 is located between the first light-transmitting substrate 14 and the electrophoretic dielectric layer 12. A second transparent electrode layer 20 is located between the second light-transmitting substrate 16 and the electrophoretic layer 12. The electrode layers 18 and 20 may each contain a transparent flexible polyethylene terephthalate (PET) film with a transparent flexible indium tin oxide (ITO) electrode coated on its inner surface.

[0062] The electrophoretic layer 12 includes a light-transmitting polymer structure 22 (e.g., a polymer structure depicted in FIG. 2A or FIG. 3A) on the electrode layer 20 and an electro-optic medium 24 contained in the units 30 defined by the polymer structure 22. The polymer structure 22 can be formed by an imprinting process.

[0063] As shown in FIG. 2B and 2C, the electro-optic medium 24 in the electrophoretic layer 12 contains charged pigment particles 38 dispersed in a suspension fluid (e.g., a non-polar solvent) 40. The charged particles 38 move through the suspension fluid 40 under the action of an electric field. As discussed in further detail below, applying a driving voltage between the first electrode 18 and the second electrode 20 causes the electro-optic medium 24 to switch between a first light-absorbing off state (FIG. 2B) and a second light-transmitting on state (FIG. 2C).

[0064] Referring back to FIG. 2A, the exemplary polymer structure 22 includes a substrate 26 and a wall structure 28 extending from one surface of the substrate 26. The wall structure 28 defines a plurality of units or volumes 30 for receiving and separating the electro-optic medium 24. The substrate 26 of the polymer structure 22 includes a plurality of microwells 32 dispersed on each unit 30 for receiving and concentrating charged pigment particles 38, thereby limiting the space occupied by the particles 38 in a second light-transmitting state (FIG. 2C). In one or more embodiments, the substrate 26 includes a tapered surface 44 leading to each microwell 32 to facilitate the movement of the particles 38 into the microwell 32 in the second light-transmitting state.

[0065] The wall structure 28 formed on the substrate 26 includes a plurality of pillar structures 34 and connecting wall elements 36 connecting adjacent pillar structures 34. Each pillar structure 34 includes a distal surface 37 parallel to the substrate 26. The distal surface 37 is preferably similar in size and shape to the plurality of microwells 32. In one or more embodiments, the distal surface 37 of the column structure 34 is blackened (or otherwise colored) to resemble the microwells 32 of the polymer structure 22 after the pigment particles 38 are filled in the second transparent state.

[0066] In contrast, the distal surface of the connecting wall element 36 is transparent and not blackened. Since the column structure 34 provides almost all the structural support and sealing adhesion for the polymer structure 22, the connecting wall element 36 can have a reduced thickness and a smaller surface area. For example, the total surface area of ​​the connecting wall element 36 can be less than 1% of the total area of ​​the polymer structure 22, so that even without a blackened surface on the connecting wall element 36, the desired transmittance (%T) in the closed state will be within the desired range.

[0067] The distal surface 37 of the column 34, together with a plurality of microwells 32, is arranged on the surface of the polymer structure 22 in a predetermined pattern configured to suppress diffraction when the unit 10 is in the transparent open state. This pattern can be generated using various algorithms. In one or more embodiments, the pattern may be generated using a blue noise algorithm, a dithering algorithm, a non-repeating single-tile algorithm, an organically inspired algorithm (such as a leaf-sequence spiral algorithm), or a similar algorithm.

[0068] To alter the desired optical properties, the distal surface 37 of the pillar structure 34 may differ in size or shape from the microwell 32.

[0069] The polymer structure 22 may include additional freestanding (i.e., separate from the wall structure 28) pillar structures 34 to provide additional structural support for sealing adhesion. These pillars may be part of a predetermined pattern described above, generated using blue noise or other algorithms.

[0070] It should be noted that the figures (including FIG. 2A) are not necessarily drawn to scale. In some embodiments, the spacing between the microwell 32 and the distal surface 37 of the pillars in the polymer structure 22 ranges from 50 micrometers to 5,000 micrometers.For example, a smart glass device incorporating a light modulator 10 with a 250-micrometer well spacing typically has between 2,000 and 6,000 microwells 32 laterally along its surface and between 2,000 and 20,000 microwells longitudinally along its surface, or a total number of microwells in an array between 4 million and 120 million.

[0071] The following two examples illustrate possible approximate dimensions of polymer structural features. Specification 9 / 15 pages 15 CN 121941954 A

[0072]

[0073] FIG2B is a cross-sectional view of a portion of the light modulator unit 10 in a dark (off) state, wherein charged pigment particles 38 in the electro-optic medium 24 are diffusely distributed on the observation surface and adjacent to the inner surface of the electrode layer 18. The charged pigment particles 38 absorb light incident on the unit 10.

[0074] FIG. 2C shows the light modulator unit 10 in the on state, where charged pigment particles 38 are concentrated in microwells 32 of the polymer structure 22.

[0075] The on state is formed when a voltage having the opposite polarity to that of the charged particles 38 is applied to the electrodes 20 on the substrate 16 to form an electric field between the opposing electrodes 18, 20. This electric field drives the charged particles 38 to move toward the inner surface of the substrate 16, and upon encountering the conical surface 44, the particles 38 migrate to and concentrate in the microwells 32. The depth of the microwells 32 is sufficient to accommodate the concentrated particles 38 in the on state. This depends on the volume required for the concentration of the particles 38, and the volume, in turn, depends on the particle load in the ink suspension fluid. The latter determines the transmittance in the dark state. When the voltage polarity is reversed, the off state is formed (FIG. 2B), and the charged particles 38 are attracted to the inner surface of the substrate 14, where the charged particles diffuse adjacent to their electrodes 18. The applicant's U.S. Patent No. 10,067,398 (titled "Electrophoresis Apparatus with Transparent Optical States") describes in more detail the use of protrusions to form optical states in an electrophoresis apparatus. It is understood that the charged particles 38 can be driven by a time-varying voltage, for example, a voltage waveform ranging from 0 to ±500V, although typically below this range.

[0076] The electro-optic medium 24 and the polymer structure 22 are preferably optically transparent and have matched refractive indices. This allows light incident on the unit 10 (without being absorbed by the pigment particles 38) to be transmitted unimpeded (i.e., without refraction or diffraction) at the interface between the suspending fluid of the electro-optic medium 24 and the polymer structure 22.

[0077] For example, a sealing layer having a polymer component can be applied to the polymer structure 22 to seal the electro-optic medium 24 within the plurality of units 30. The pillar structure 34 provides structural support and sealing adhesion for the sealing layer.

[0078] In addition, one or more layers of adhesive (such as optically transparent adhesives available from, for example, Norland Corporation) can be used to bond various films and structures to each other.

[0079] In the lamination step, an electro-optic medium 24 can be used to fill the unit 30, which applies the imprinted polymer structure 22 previously formed on (and bonded to) the first substrate to the second substrate, with the electro-optic medium 24 located between them. Preferably, the lamination step uses a pair of oriented NIP rollers such that the substrates move between the rollers from top to bottom (instead of from left to right). Fluid in droplets above the NIP points between the substrates is laminated into cavities within the imprinted polymer by the rollers as the substrates pass through the NIP points. The orthogonal distance between the parallel planes of the substrates is determined by the polymer wall structure as the substrates pass through the NIP points. Preferably, the top of the polymer wall is bonded to the second substrate after or simultaneously with lamination, during a UV light (or other radiation) curing stage.

[0080] The optical modulator may have a flexible thin-film substrate and be flexible enough to be compatible with roll-to-roll production. The thin-film device exhibits significant structural strength and separates the fluid layer within cavities, each accommodating an independent volume of ink. These ink volumes are self-sealing and isolated from adjacent cavities, as described on pages 10 / 15 of the specification, CN 121941954 A. The structural strength of the embodiment stems from the selection of its polymer structure and polymer sealing material. This structural strength includes the strength required to withstand permanent lamination to a glass plate within a laminated safety glass containing an EVA or PVB interlayer as an optical adhesive between the device and the glass plate. The device materials are selected to withstand mechanical shocks and extreme environmental conditions (sunlight and outdoor temperatures) under normal use.

[0081] Figures 3A and 3B illustrate an optical modulator unit with an alternative polymer structure disclosed in U.S. Patent No. 10067398. Figure 3A shows a cross-sectional view of the optical modulator unit 449, and Figure 3B shows a top plan view of the polymer structure 158 of the optical modulator unit 449. The polymer structure 158 is non-planar and includes protrusions 795, the extent of which coincides with the channel 101 and the cavity 488.

[0082] Figures 3A and 3B show the light modulator unit in the on state. Black charged particles 11 are deflected (or moved across) the surface of the protrusions 795 in the electric field and concentrate in the gaps of the protrusions 795 to form an aperture 1006. The non-planar polymer structure 158 has protrusions 795 arranged non-periodically in the electrophoresis unit 614. The surface shape, cross-sectional area, cross-sectional geometry and orientation of the protrusions 795 are different from each other and can be random or have a certain degree of randomness. This type of protrusion 795 is asymmetrical and has surfaces with different areas and slopes to enhance the randomness of the aperture 1006 defined by the protrusions in the light state. When light is irradiated by embodiment 449, it diffracts randomly, thereby avoiding the perception of diffraction patterns around a bright light source observed through the device.

[0083] The channel 101 coincides with the gap of the protrusion 795 and accommodates concentrated black charged particles 11 in the open state. The channel 101 is a recess in the non-planar polymer structure 158 and is at least partially below the horizontal plane of the protrusion 795, as shown in FIG3A. In some embodiments, the volume of concentrated black charged particles filling the gap of the protrusion is proportional to the particle load in the electrophoretic ink (e.g., the particle load is in the range of 5% to 30% of the ink mass). When viewed on the surface of the device in the open state, the concentrated particles form a light absorption region (i.e., an obstacle) that limits the maximum light transmittance. Advantageously, the channel 101 minimizes the surface area covered by the concentrated black charged particles 11 in the open state by concentrating (or stacking) the particles in the z-axis direction of the unit 614.

[0084] In the light modulator unit 449, each protrusion 795 is tightly surrounded by its channel 101 and polymer wall 76, and their extent defines the electrophoretic ink cavity 488. In the view of FIG3B, the black mask 606 covering the polymer wall 76 is located in the peripheral region of the aperture in the second light state (i.e., it does not constitute part of the outer periphery of the aperture), and its wall edge is adjacent to the concentrated black particles 11, as shown by the light barrier dimension 1004. Advantageously, the black mask 606 covering the wall 76 does not diffract light because it does not coincide with the light-transmitting region along its outer periphery (in the front view). In the embodiment associated with 449, the channel 101 is absent, and the black charged particles 11 are concentrated in the volume between the protrusion 795 and its surrounding wall 76, and adjacent to the bottom electrode 60. More generally, in embodiments, it is advantageous for the polymer wall segment (or its length in the front view) to coincide with the outer peripheral region of the protrusion, such that in the open state, the concentrated black charged particles are adjacent to the edge of the wall segment.

[0085] Preferably, the non-planar polymer structure 158 is continuous within the unit 614 and isolates the electrophoretic ink layer 613 from the bottom electrode 60. Both the discrete aperture 1006 and the continuous light-blocking region 1004 (i.e., the concentrated region of black charged particles and the black mask region) are random or have a degree of randomness. To minimize or avoid perceiving the diffraction pattern generated by the black mask 606 on the polymer wall 76, the arrangement of the polymer wall and the cavities 488 formed therein is aperiodic.

[0086] In embodiments associated with 449, the cavities, polymer walls, and channels coincide with the extent of more than one microstructure. For example, each electrophoretic ink cavity defined by its surrounding polymer wall 76 contains two or more protrusions, a portion of which coincides with the wall, and each protrusion is surrounded by a channel.

[0087] The nonplanar polymer structure 158 in device 449 is derived from a photosensitive polymer (cured photoresist) exposed and developed by a laser beam or electron beam (e-beam) to reveal the surface of the microstructure.Preferably, each microstructure is independently written, non-symmetrical, and randomly oriented. More preferably, the parameters defining each microstructure are uncorrelated, and the close packing of microstructures and cavities has a random center.

[0088] In embodiments, the sizes of the aperture and barriers are maximized to minimize the total perimeter per square unit surface area. The upper limit is determined by the resolution of a typical observer's eye. Preferably, the aperture and barriers are small enough that their geometry is not apparent in a frontal view. In embodiments where the microstructures are protruding and the black charged particles form discrete apertures in the open state, the maximum angle subtended by the apertures to the observer at the desired viewing distance is 1 arcminute (corresponding to 290 micrometers at a viewing distance of 1 meter), and preferably 0.6 arcminutes (corresponding to 174.5 micrometers at a viewing distance of 1 meter). The angle subtended by the aperture spacing (i.e., the aperture and the concentrated charged particle region) is twice these limits. In embodiments where the microstructure is recessed and black charged particles form discrete obstacles in the second light state, the maximum angle subtended by the obstacles to the observer at the desired observation distance is 1 arcminute (corresponding to approximately 290 micrometers at a 1-meter observation distance), and preferably 0.6 arcminutes (corresponding to approximately 174.5 micrometers at a 1-meter observation distance). The angle subtended by the obstacle spacing (i.e., the obstacle and the light-transmitting area) is twice these defined values.

[0089] FIG4 is a simplified exploded view of an exemplary switchable large-area light modulator 200 comprising a plurality of smaller independent light modulator units 202 according to one or more embodiments. These independent light modulator units 202 are arranged side by side in an array. The array is sandwiched between two large light-transmitting substrates 204 and 206, on the inner surfaces of which are coated with light-transmitting electrode layers 208 and 210, respectively.

[0090] FIG5 is a simplified cross-sectional view of one of the independent light modulator units 202 according to one or more embodiments. The optical modulator unit 202 includes a first light-transmitting substrate 212 having opposing inner surfaces 214 and outer surfaces 216. The first light-transmitting substrate 212 has a plurality of conductive vias 218 extending between the inner surface 214 and the outer surface 216. A first light-transmitting conductive layer 220 is disposed on the inner surface 214 of the first light-transmitting substrate 212 and is in electrical contact with the conductive vias 218.

[0091] The optical modulator unit 202 also includes a second light-transmitting substrate 222 having opposing inner surfaces 224 and outer surfaces 226. The second light-transmitting substrate 222 also has a plurality of conductive vias 228 extending between the inner surface 224 and the outer surface 226. A second light-transmitting conductive layer 230 is disposed on the inner surface 224 of the second light-transmitting substrate 222 and is in electrical contact with the conductive vias 228 of the second light-transmitting substrate 222.

[0092] In one or more embodiments, conductive vias 218, 228 include through-holes 242 in the first light-transmitting substrate 212 and the second light-transmitting substrate 222, which are filled with a conductive material. The conductive material is preferably light-transmitting, but this is not mandatory.

[0093] As an alternative to through-holes filled with conductive material, vias 218, 228 may include conductive particles embedded at specific locations in the substrates 212, 222. These particles may be aligned during the extrusion process used to manufacture the substrates 212, 222.

[0094] The conductive vias 218, 228 form contact points on the outer surfaces 216, 226 of the first light-transmitting substrate 212 and the second light-transmitting substrate 222. In one or more embodiments, the contact points have an average diameter of at least 0.1 micrometers to at most 100 micrometers. In some embodiments, the contact points have an average diameter of at least 25 micrometers to at most 100 micrometers. In some embodiments, the outer surfaces 216, 226 of the first light-transmitting substrate 212 and the second light-transmitting substrate 222 have an average density ranging from at least 10 contact points per square centimeter to at most 1000 contact points per square centimeter. In some embodiments, the contact points occupy less than 10% (preferably less than 1%) of the surface area of ​​the outer surfaces 216, 226 of the first light-transmitting substrate 212 and the second light-transmitting substrate 222.

[0095] The conductive vias 218, 228 of the first light-transmitting substrate 212 and the second light-transmitting substrate 222 may be the same as or similar to the vias formed in the electrophoretic display disclosed in US 2022-0107541, which is incorporated herein by reference. Figure 6 (reproduced from US 2022-0107541) is described in that document as showing a front planar laminate 100A, including a front planar light-transmitting substrate 102 having an inner surface 112 and an outer surface 114 opposite to the inner surface 112. The front-plane transparent substrate 102 is a composite structure comprising a continuous portion 102a and a plurality of openings 102b distributed within the continuous portion 102a. The openings 102b include conductive material 115, which forms an electrical connection (via) between the conductive layer 104 and one or more contact points 116 on the outer surface 114. The conductive layer 104 may be divided into two or more segments, each segment contacting a subset of the contact points (not shown), thereby forming a structure in which a short circuit occurring in one segment does not cause failure in other segments. The electrical connection may be applied locally or across the entire outer surface. A protective layer (not shown), such as a coating of transparent acrylic polymer or silicone, may be added to seal some or all of the contact points and provide a moisture barrier while preventing unwanted short circuits after assembly.The continuous portion 102a can be made of glass or a transparent polymer material (such as polyethylene terephthalate (PET)) which is etched, cut, laser ablated, or any suitable perforation technique to form openings. Alternatively, the continuous portion 102a can be microindented to create vias or recesses that can be filled during sputtering, by which a conductive layer material (such as ITO) is added. Alternatively, a PET film can be heated and softened, stretched onto a mold, and blasted with high-pressure gas to form holes. These openings can then be filled with a conductive material to form contact points 116. These openings can be provided in various shapes, sizes, and densities to suit the current application. Regardless of shape, the individual and average contact point size can be defined based on a given contact point size. Unless otherwise specified or apparent from the context, the term “size” refers to the length, width, or diameter of the contact point along the layer surface. Generally, “length” refers to the extension in the longitudinal direction, while “width” refers to the extension in the transverse direction. When “diameter” is used with respect to a contact point, it is intended to identify the longest straight line segment between two points on the outer surface of the front-plane transparent substrate at that contact point. In some non-exclusive embodiments, the geometry of the contact point 116 makes its average diameter range from about 0.1 µm to about 100 µm. In other embodiments, the average diameter of the contact point ranges from about 0.5 µm to about 10 µm.

[0096] Referring back to FIG5, the electro-optic dielectric layer 232 is disposed between and in contact with the first transparent conductive layer 220 and the second transparent conductive layer 230, such that the electro-optic dielectric can be addressed by a driving voltage applied to the conductive layers 220, 230.

[0097] In one or more embodiments, the electro-optic dielectric layer 232 includes an encapsulated electrophoretic dielectric. In one or more embodiments, the electrophoretic dielectric is encapsulated in a microcapsule or microcup. FIG5 shows a set of microcups defined by walls 234 formed by an imprinting process. The microcups can be sealed using a layer 236 in contact with the first transparent conductive layer. The electro-optic dielectric layer 232 also includes an optional primer layer 238 located on the other side of the microcup structure.

[0098] The electrophoretic medium comprises charged pigment particles dispersed in a nonpolar solvent. The application of a driving voltage causes the electrophoretic medium to switch between a first light-absorbing (i.e., off) state and a second light-transmitting (i.e., on) state by moving between a dispersed particle state and an aggregated particle state, respectively.

[0099] In one or more embodiments, the electro-optic dielectric layer 232 also includes a polymer structure (e.g., polymer structure 22 depicted in FIG. 2A or polymer structure 158 depicted in FIG. 3A) to guide the movement of charged pigment particles to the aggregated particle state.The polymer structure 22 includes a plurality of microwells 32, wherein charged pigment particles aggregate in the microwells 32 of the polymer structure 22 when the electro-optic medium is in a second light-transmitting state; and when the electro-optic medium is in a first light-absorbing state, the charged pigment particles are dispersed on the polymer structure, similar to the process shown in Figures 2B and 2C discussed above.

[0100] The electro-optic medium in each electro-optic unit 202 is preferably bistable.

[0101] FIG7 is a simplified cross-sectional view of a portion of an optical modulator 200 having two independent optical modulator units 202 (as shown in FIG5) according to one or more embodiments. The optical modulator unit 202 is sandwiched between two larger light-transmitting substrates 204 and 206, on the inner surfaces of which light-transmitting electrode layers 208 and 210 are respectively coated. The light-transmitting electrode layers 208 and 210 are in electrical contact with vias 218 and 228, respectively. Thus, the light-transmitting electrode layers 208 and 210 are electrically connected to the first light-transmitting conductive layer 220 and the second light-transmitting conductive layer 230 of each individual light modulator unit 202, respectively. This structure provides a reliable and secure electrical connection for each individual light modulator unit 202 without compromising the transparency of the light modulator 200 in the on state.

[0102] In one or more embodiments, the light-transmitting conductive layers 208, 210, 220, and 230 comprise aluminosilicate, indium tin oxide (ITO), poly(3,4-ethylenedioxythiophene), or combinations thereof. Alternatively, the light-transmitting conductive layers 208, 210, 220, and 230 may comprise organic materials such as PEDOT (polyethylenedioxythiophene). Furthermore, the light-transmitting conductive layers 208, 210, 220, and 230 may comprise composite materials, such as a matrix comprising graphene or carbon nanotubes. The light-transparent conductive layers 208, 210, 220, and 230 may also comprise a sparse mesh, such as a printed mesh or nanowire formulation.

[0103] In one or more embodiments, each of the light-transparent substrates 204, 206, 212, and 222 comprises a polymer, including acrylates, methacrylates, vinylbenzene, vinyl ethers, urethanes, or multifunctional epoxy compounds.

[0104] In one or more embodiments, the outer substrates 204 and 206 comprise any light-transparent material having good optical quality, scratch resistance, and the ability to protect other components from degradation caused by oxygen and water penetration. In one or more embodiments, the light-transparent substrates 204 and 206 comprise glass or a light-transparent plastic material such as polyethylene terephthalate, polycarbonate, or other polymers known in the art. In some embodiments, each substrate has a thickness of 25-100 micrometers.

[0105] Figures 8A-8C illustrate exemplary processes for constructing transparent substrates 212, 222 and transparent conductive layers 220, 230 in each optical modulator unit 202 according to one or more embodiments.

[0106] As shown in FIG. 8A, the light-transmitting plastic substrates 212, 222 are laminated onto a removable pad 240. As shown in FIG. 8B, a plurality of through holes 242 are formed through the substrates 212, 222, and the depth is preferably not completely through the pad 240. The holes 242 can be formed using various processes, such as laser drilling.

[0107] Next, as shown in FIG. 8C, the perforated substrates 212, 222 are coated with a light-transmitting conductive material that penetrates the drilled holes 242. This coating can be applied once or multiple times. Preferably, the coated material is 100% solid so that it does not shrink when drying. Examples of suitable materials are formulations comprising UV-curable monomers in which conductive light-transmitting materials such as carbon nanotubes or graphene are dispersed. An example of a suitable conductive light-transmitting material is Tuball™ graphene nanotubes manufactured by OCSiAl in Luxembourg.

[0108] This process manufactures a light-transmitting substrate coated with a light-transmitting conductive layer. As shown in Figure 9, two such structures are used in the fabrication of each individual light modulator unit 202. Once these structures are assembled with the electro-optic dielectric layer 232, the pad 240 is removed, and the individual light modulator units 202 are arranged in an array and sandwiched between two larger light-transmitting substrates 204 and 206 coated with light-transmitting electrode layers 208 and 210 to form the light modulator shown in Figure 7.

[0109] The light-transmitting electrode layers 208 and 210 may contain the same material as the light-transmitting electrode layers 220 and 230, but this is not required. A preferred material for the electrode layers 208 and 210 is a UV-curable composition containing conductive light-transmitting fillers such as graphene or carbon nanotubes. To assemble the structure shown in Figure 7, the individual light modulator units 202 are laminated between the substrates 204 and 206 coated with electrode layers 208 and 210, and then the entire structure is irradiated to cure the materials 208 and 210.

[0110] Therefore, this process enables the fabrication of a large-area light modulator 200 using conventional equipment, from an array of smaller light modulator subunits 202, without compromising optical transparency.

[0111] The light modulator 200 can modulate light transmission and / or visual access when integrated into a window of a building, including single-pane, double-pane, and triple-pane windows. In the latter two cases, the light modulator is preferably located in a window pane adjacent to the external environment so that absorbed solar energy can be dissipated to the external environment through convection and thermal radiation. In other window and / or opening embodiments, the device modulates sunlight transmission into the interior of a vehicle or public transportation vehicle (e.g., a bus, train, tram, ferry, or ship), minimizes glare, and provides occupants with a degree of privacy relative to external observers while maintaining external visibility.In addition, other embodiments include serving as light shields, light attenuators, variable transmittance sheets, variable absorbance sheets, variable reflectance sheets, one-way mirrors, sunshades, or skylights.

[0112] In addition to large-area electro-optic modulators, the techniques disclosed herein can also be applied to the manufacture of large-area electro-optic displays. FIG10 is a simplified exploded view of an exemplary large-area light display 300 composed of a plurality of smaller, independent display units 302 according to one or more embodiments. These independent display units 302 are arranged side by side in an array. A large light-transmitting substrate 204, on which a light-transmitting electrode layer 208 is coated on its inner surface, is superimposed on the observation surface of the array of display units. Unlike the large-area light modulators discussed above, only the observation surface of the display units 302 needs to be covered with a light-transmitting substrate. The opposing surfaces of the display units 302 may be adhered to one or more backplane units to apply a driving voltage to the electro-optic medium in the display units 302. Each display unit 302 includes an electro-optic dielectric layer covered by a transparent substrate coated with a light-transmitting conductive layer. The transparent substrate has multiple conductive vias, similar to the transparent substrates 212 and 222 described above with vias 218 and 228 in the light modulator. Thus, the light-transmitting conductive layer 208 can be connected to the array of display units 302 without compromising the transparency of the viewing surface of the display.

[0113] The electrophoretic film for each display unit 302 can be produced using a roll-to-roll process as shown in FIG. 11,397,366, which is similar to the process for producing a light-collimating film described in detail in US Patent No. 11,397,366 (which is incorporated herein by reference). As shown in FIG. 11, the process involves the following steps: In the first step, an imprinted composition layer 70 (e.g., a thermoplastic, thermosetting, or precursor thereof, optionally containing a solvent) is deposited on a transparent substrate 61. The transparent substrate 61 is coated with a conductive layer and includes an array of conductive vias similar to substrates 212 and 222. (If a solvent is present, it evaporates easily.) A primer layer (i.e., an electrode protective layer) can be used to enhance the adhesion between the imprinted composition layer and the support layer (which may be PET). Furthermore, an adhesion promoter can be used in the primer layer to improve adhesion to the support layer. In the second step, the layer 70 is imprinted using a pre-patterned imprinting tool 62 at a temperature above the glass transition temperature of the layer material. (The primer and / or adhesion promoter can be adjusted to reduce adhesion to the imprinting tool 62.) In the third step, preferably during or after the patterned layer 70 has hardened (e.g., by cooling), it is released from the imprinting tool 62. At this point, the characteristic pattern of the elongated chamber (as described above) has been formed. In the fourth step, the elongated chamber 63 is filled with a bistable electrophoretic fluid 64.In some embodiments, the bistable electrophoretic fluid will contain a sealing composition incompatible with electrophoretic fluid 64, having a lower specific gravity than the solvent and pigment particles in electrophoretic fluid 64. In such embodiments, the sealing composition will rise to the top of the elongated chamber 63 so that it can be cured in a subsequent step. Alternatively (not shown in FIG. 11), the sealing composition may be recoated after the elongated chamber 63 has been filled with electrophoretic fluid 64. In the next step, the elongated chamber 63 filled with electrophoretic fluid 64 is sealed by curing the sealing composition (e.g., using UV radiation 65 or by heat or moisture). In a sixth step, the sealed elongated chamber is laminated to a second transparent conductive membrane 66, which may be pre-coated with an optically transparent adhesive layer 67, which may be a pressure-sensitive adhesive, a hot melt adhesive, a thermosetting adhesive, a moisture-curing adhesive, or a radiation-curing adhesive. Preferred materials for optically transparent adhesives include acrylic resins, styrene-butadiene copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, polyvinyl butyral, cellulose acetate butyrate, polyvinylpyrrolidone, polyurethanes, polyamides, ethylene-vinyl acetate copolymers, epoxy compounds, multifunctional acrylates, vinyl groups, vinyl ethers and their oligomers, polymers and copolymers. In the final step, the finished sheet can be cut, for example using a blade 69 or a laser cutter. In some embodiments, an eighth step can be performed on the finished film, including laminating another optically transparent adhesive and a release sheet to transport it as segmented sheets or rolls and to cut it to the desired size when used, for example for integration into a display or other device / substrate.

[0114] It will be apparent to those skilled in the art that many changes and modifications can be made to the specific embodiments of the invention described above without departing from the scope of the invention. Therefore, the entire foregoing description should be interpreted exemplarily and not restrictively.Instruction Manual Page 15 / 15, 21 CN 121941954 A, Figure 1; Instruction Manual Figure 1 / 16, 22 CN 121941954 A, Figure 2A; Instruction Manual Figure 2 / 16, 23 CN 121941954 A, Figure 2B; Instruction Manual Figure 3 / 16, 24 CN 121941954 A, Figure 2C; Instruction Manual Figure 4 / 16, 25 CN 121941954 A, Figure 3A; Instruction Manual Figure 5 / 16, 26 CN 121941954 A, Figure 3B; Instruction Manual Figure 6 / 16, 27 CN 121941954 A, Figure 4; Instruction Manual Figure 7 / 16, 28 CN 121941954 A, Figure 5; Instruction Manual Figure 8 / 16, 29 CN 121941954 A, Figure 6; Instruction Manual Figure 9 / 16, 30 CN 121941954 A, Figure 7. Figure 8A, page 10 / 16, CN 121941954 A; Figure 8B, page 11 / 16, CN 121941954 A; Figure 8C, page 13 / 16, CN 121941954 A; Figure 9, page 10 / 11, page 11 / 16, CN 121941954 A; Figure 11, page 12 / 16, CN 121941954 A.

Claims

1. An electro-optical device, comprising: (a) A plurality of electro-optical units arranged side by side, each of the electro-optical units comprising: A first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; A first transparent conductive layer that is electrically contacted with the conductive vias of the first transparent substrate on the inner surface of the first transparent substrate. A second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; A second transparent conductive layer that is electrically contacted with the conductive vias of the second transparent substrate on the inner surface of the second transparent substrate; and An electro-optic dielectric layer between the first and second transparent conductive layers and in contact with the first and second transparent conductive layers; (b) A third light-transmitting substrate superimposed on the outer surface of the first light-transmitting substrate of each of the multiple electro-optic units; (c) A third transparent conductive layer between a third transparent substrate and a plurality of electro-optic units, the third transparent conductive layer being in electrical contact with a conductive via of a first transparent substrate of each of the plurality of electro-optic units; (d) A fourth light-transmitting substrate superimposed on the outer surface of the second light-transmitting substrate of each of the plurality of electro-optic units; and (e) A fourth transparent conductive layer between a fourth transparent substrate and a plurality of electro-optic units, the fourth transparent conductive layer being electrically contacted with a conductive via of a second transparent substrate of each of the plurality of electro-optic units.

2. The apparatus of claim 1, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic dielectric.

3. The apparatus according to claim 2, wherein the encapsulated electrophoretic medium comprises an electrophoretic medium encapsulated in a microcapsule or microcup.

4. The apparatus according to any one of the preceding claims, wherein the apparatus is a switchable optical modulator, and wherein the electro-optic medium in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent, and the electro-optic medium switches between a first light-absorbing state and a second light-transmitting state by moving between a dispersed particle state and an aggregated particle state.

5. The apparatus of claim 4, wherein the electro-optic dielectric layer in each electro-optic unit further comprises a polymer structure having a plurality of microwells, wherein when the electro-optic dielectric is in the second light-transmitting state, the charged pigment particles are collected in the microwells of the polymer structure, and when the electro-optic dielectric is in the first light-absorbing state, the charged pigment particles are dispersed in the polymer structure.

6. The apparatus according to any one of the preceding claims, wherein a driving voltage is applied between the third and fourth transparent conductive layers to cause the electro-optic medium in each electro-optic unit to switch between the first light-absorbing state and the second light-transmitting state.

7. The apparatus according to any one of the preceding claims, wherein the electro-optic medium in each electro-optic unit is bistable.

8. The apparatus according to any one of the preceding claims, wherein the first light-transmitting substrate, the second light-transmitting substrate, the third light-transmitting substrate or the fourth light-transmitting substrate comprises a polymer comprising acrylate, methacrylate, vinylbenzene, vinyl ether, urethane or a multifunctional epoxy compound.

9. The apparatus according to any one of the preceding claims, wherein the third or fourth light-transmitting substrate comprises plastic or glass.

10. The apparatus according to any one of the preceding claims, wherein the first transparent conductive layer, the second transparent conductive layer, the third transparent conductive layer, or the fourth transparent conductive layer comprises: (a) Materials selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene) and combinations thereof; (b) Organic materials; (c) Composite materials; or (d) Sparse meshes.

11. The apparatus of claim 10, wherein the organic material comprises PEDOT (polyethylene dioxythiophene), the composite material comprises a matrix containing graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation.

12. The apparatus according to any one of the preceding claims, wherein the conductive vias in the first and second light-transmitting substrates form contact points on the outer surfaces of the first and second light-transmitting substrates, the contact points having an average diameter of at least 0.1 micrometers to at most 100 micrometers.

13. The device according to any of the preceding claims, wherein the contact point has an average diameter of at least 25 micrometers to at most 100 micrometers.

14. The apparatus according to any of the preceding claims, wherein the outer surfaces of the first light-transmitting substrate and the second light-transmitting substrate have an average density ranging from at least 10 contact points per square centimeter to at most 1,000 contact points per square centimeter.

15. The apparatus according to any of the preceding claims, wherein the conductive via occupies less than 10% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates.

16. The apparatus according to any of the preceding claims, wherein the conductive via occupies less than 1% of the surface area of ​​the outer surfaces of the first and second light-transmitting substrates.

17. The apparatus according to any one of the preceding claims, wherein the conductive via includes a through-hole in the first light-transmitting substrate and the second light-transmitting substrate, filled with conductive material or embedded with conductive particles.

18. A window comprising the means according to any of the preceding claims.

19. A method for manufacturing an electro-optical device, comprising the following steps: (a) Providing a plurality of electro-optic units, each of the electro-optic units comprising: A first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; A first transparent conductive layer that is electrically contacted with the conductive vias of the first transparent substrate on the inner surface of the first transparent substrate. A second light-transmitting substrate having opposing inner and outer surfaces, the second light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces of the second light-transmitting substrate; A second transparent conductive layer that is electrically contacted with the conductive vias of the second transparent substrate on the inner surface of the second transparent substrate; and An electro-optic dielectric layer between the first and second transparent conductive layers and in contact with the first and second transparent conductive layers; (b) The plurality of electro-optical units are arranged in a side-by-side, flat layout; and (c) Press the third light-transmitting substrate covered with the third light-transmitting conductive layer onto one side of the plurality of electro-optic units, and press the fourth light-transmitting substrate covered with the fourth light-transmitting conductive layer onto the opposite side of the plurality of electro-optic units; The third light-transmitting substrate is superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units, and the third light-transmitting conductive layer is disposed between the third light-transmitting substrate and the plurality of electro-optic units, and the third light-transmitting conductive layer is in electrical contact with the conductive via of the first light-transmitting substrate of each of the plurality of electro-optic units. The fourth light-transmitting substrate is superimposed on the outer surface of the second light-transmitting substrate of each of the plurality of electro-optic units, and the fourth light-transmitting conductive layer is disposed between the fourth light-transmitting substrate and the plurality of electro-optic units, and the fourth light-transmitting conductive layer is in electrical contact with the conductive via of the second light-transmitting substrate of each of the plurality of electro-optic units.

20. The method of claim 19, wherein step (a) comprises: (i) A hole is formed in the first light-transmitting substrate, and a conductive material is deposited on the inner surface of the first light-transmitting substrate to form a first light-transmitting conductive layer and a conductive via. (ii) forming a hole in the second light-transmitting substrate and depositing a conductive material on the inner surface of the second light-transmitting substrate to form a second light-transmitting conductive layer and a conductive via.

21. The method of claim 20, wherein forming holes in the first and second light-transmitting substrates includes using laser drilling.

22. The method of claim 20, wherein the conductive material comprises a conductive transparent material dispersed in a UV-curable monomer.

23. The method of claim 19, wherein the third and fourth transparent conductive layers comprise a conductive transparent material dispersed in a UV-curable monomer.

24. The method of claim 23, wherein step (c) further comprises irradiating the third transparent conductive layer and the fourth transparent conductive layer to cure the UV-curable monomer.

25. The method of claim 23, wherein the conductive transparent material comprises graphene or carbon nanotubes.

26. The method according to any of the preceding claims, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic dielectric.

27. The method according to any of the preceding claims, wherein the encapsulated electrophoretic medium comprises an electrophoretic medium encapsulated in a microcapsule or microcup.

28. The method according to any one of the preceding claims, wherein the electro-optic device is a switchable optical modulator, and wherein the electro-optic medium in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent, and the electro-optic medium switches between a first light-absorbing state and a second light-transmitting state by moving between a dispersed particle state and an aggregated particle state.

29. The method of claim 28, wherein the electro-optic dielectric layer in each electro-optic unit further comprises a polymer structure having a plurality of microwells, wherein when the electro-optic dielectric is in the second light-transmitting state, the charged pigment particles are collected in the microwells of the polymer structure, and when the electro-optic dielectric is in the first light-absorbing state, the charged pigment particles are dispersed in the polymer structure.

30. The method according to any one of the preceding claims, wherein a driving voltage is applied between the third and fourth transparent conductive layers to cause the electro-optic medium in each electro-optic unit to switch between the first light-absorbing state and the second light-transmitting state.

31. The method according to any one of the preceding claims, wherein the electro-optic medium in each electro-optic unit is bistable.

32. The method according to any one of the preceding claims, wherein the first light-transmitting substrate, the second light-transmitting substrate, the third light-transmitting substrate or the fourth light-transmitting substrate comprises a polymer comprising acrylate, methacrylate, vinylbenzene, vinyl ether, urethane or a multifunctional epoxy compound.

33. The method according to any one of the preceding claims, wherein the third or fourth light-transmitting substrate comprises plastic or glass.

34. The method according to any one of the preceding claims, wherein, The first, second, third, or fourth transparent conductive layer comprises: (a) a material selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene) and combinations thereof; (b) an organic material; (c) a composite material; or (d) a sparse mesh.

35. The method of claim 34, wherein the organic material comprises PEDOT (polyethylene dioxythiophene), the composite material comprises a matrix containing graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation.

36. The method according to any one of the preceding claims, wherein the conductive vias in the first and second light-transmitting substrates form contact points on the outer surfaces of the first and second light-transmitting substrates, wherein the contact points have an average diameter of at least 0.1 micrometers to at most 100 micrometers.

37. The method according to any of the preceding claims, wherein the contact point has an average diameter of at least 25 micrometers to at most 100 micrometers.

38. The method according to any one of the preceding claims, wherein the outer surfaces of the first light-transmitting substrate and the second light-transmitting substrate have an average density ranging from at least 10 contact points per square centimeter to at most 1,000 contact points per square centimeter.

39. The method according to any one of the preceding claims, wherein the conductive via occupies less than 10% of the surface area of ​​the outer surfaces of the first light-transmitting substrate and the second light-transmitting substrate.

40. The method according to any one of the preceding claims, wherein the conductive via occupies less than 1% of the surface area of ​​the outer surfaces of the first light-transmitting substrate and the second light-transmitting substrate.

41. The method according to any one of the preceding claims, wherein the conductive via includes a through-hole in the first light-transmitting substrate and the second light-transmitting substrate, which is filled with conductive material or embedded with conductive particles.

42. An electro-optical device, comprising: (a) A plurality of electro-optical units arranged side by side, each of the electro-optical units comprising, in sequence: A first light-transmitting substrate having opposing inner and outer surfaces, the first light-transmitting substrate having a plurality of conductive vias extending between the inner and outer surfaces; A first transparent conductive layer that is electrically contacted with the conductive vias of the first transparent substrate on the inner surface of the first transparent substrate. An electro-optic dielectric layer in contact with the first transparent conductive layer; and A backplate containing at least one electrode; (b) A second light-transmitting substrate superimposed on the outer surface of the first light-transmitting substrate of each of the plurality of electro-optic units; and (c) A second transparent conductive layer between the second transparent substrate and the plurality of electro-optic units, the second transparent conductive layer being electrically contacted with a conductive via of the first transparent substrate of each of the plurality of electro-optic units.

43. The apparatus of claim 42, wherein the electro-optic dielectric layer in each electro-optic unit comprises an encapsulated electrophoretic dielectric.

44. The apparatus of claim 43, wherein the encapsulated electrophoretic medium comprises an electrophoretic medium encapsulated in a microcapsule or microcup.

45. The apparatus according to any of the preceding claims, wherein the electro-optic medium in each electro-optic unit comprises charged pigment particles dispersed in a nonpolar solvent.

46. ​​The apparatus according to any one of the preceding claims, wherein the electro-optic medium in each electro-optic unit is bistable.

47. The apparatus according to any one of the preceding claims, wherein the first or second light-transmitting substrate comprises a polymer containing acrylate, methacrylate, vinylbenzene, vinyl ether, urethane, or a multifunctional epoxy compound.

48. The apparatus according to any one of the preceding claims, wherein the second light-transmitting substrate comprises plastic or glass.

49. The apparatus according to any one of the preceding claims, wherein the first transparent conductive layer or the second transparent conductive layer comprises: (a) Materials selected from the group consisting of tin alumina, indium tin oxide, poly(3,4-ethylenedioxythiophene) and combinations thereof; (b) Organic materials; (c) Composite materials; or (d) Sparse meshes.

50. The apparatus of claim 49, wherein the organic material comprises PEDOT (polyethylene dioxythiophene), the composite material comprises a matrix containing graphene or carbon nanotubes, and the sparse mesh comprises a printed mesh or nanowire formulation.

51. The apparatus according to any of the preceding claims, wherein a conductive via in the first light-transmitting substrate forms a contact point on the outer surface of the first light-transmitting substrate, the contact point having an average diameter of at least 0.1 micrometers to at most 100 micrometers.

52. The device according to any of the preceding claims, wherein the contact point has an average diameter of at least 25 micrometers to at most 100 micrometers.

53. The apparatus according to any of the preceding claims, wherein the outer surface of the first light-transmitting substrate has an average density ranging from at least 10 contact points per square centimeter to at most 1,000 contact points per square centimeter.

54. The apparatus according to any of the preceding claims, wherein the conductive via occupies less than 10% of the surface area of ​​the outer surface of the first light-transmitting substrate.

55. The apparatus according to any of the preceding claims, wherein the conductive via occupies less than 1% of the surface area of ​​the outer surface of the first light-transmitting substrate.

56. The apparatus according to any of the preceding claims, wherein the conductive via comprises a through-hole in a first light-transmitting substrate, filled with conductive material or embedded with conductive particles.

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