KR20170124348A - Method of manufacturing electrophoresis display apparatus - Google Patents

Abstract

According to various embodiments of the present invention, disclosed is a method for manufacturing an electrophoretic display device. The method of the present invention comprises the steps of: forming, on a substrate, a display layer including a first color solution having a first color and a first density, a second color solution having a second color different from the first color, and having a second density greater than the first density, a first light curable solution having a density greater than the first density, and less than the second density, and microcapsules separately having electrophoretic particles dispersed in the first and second color solutions, and charged with a first polarity; arranging the substrate in parallel with a central direction of the earth to allow the first light curable solution to vertically extend with respect to the substrate between the first and second color solutions by the density difference thereof; and forming a first separation membrane for separating the first and second color solutions from each other therebetween by irradiating light to the substrate arranged in parallel with the center direction of the earth to cure the first light curable solution. Accordingly, the electrophoretic display device of the present invention can be manufactured with a simple process, and can express three or more colors.

Description

[0001] The present invention relates to a method of manufacturing electrophoresis display apparatus,

The present invention relates to a method of manufacturing an electrophoretic display device.

In order to display three or more colors using an electrophoretic display device, which is one of the reflective display devices, it is necessary to use a color filter, to inject two or more kinds of color particles into one display cell, or to use two or more kinds of display cells .

In the case of using a color filter, light incident from the outside passes through the color filter, is reflected on the display layer, passes again through the color filter, and thus has a large optical loss. As a result, not only the total reflectance and color reproducibility are lowered but also the contrast ratio is lowered, and the manufacturing cost is increased due to the color filter.

In the case of using two or more kinds of microcapsules containing color inks of different colors, it is necessary to arrange each kind of microcapsules at a predetermined position. Also in the case of the barrier rib method, a process of injecting ink of a predetermined color into micro cells defined by the barrier rib is required. Thereby not only lowering productivity and yield but also increasing manufacturing cost.

An object of the present invention is to provide a microcapsule, an electrophoretic display device, and a method for manufacturing the electrophoretic display device, which can be manufactured by a simple process and can express three or more colors.

A microcapsule for an electrophoretic display device according to an aspect of the present invention includes a first color solution having a first color, a second color solution having a second color different from the first color, A first separator for separating the first color solution and the second color solution from each other between the color solutions, electrophoretic particles dispersed in the first color solution and the second color solution and charged with the first polarity, And a capsule outer wall surrounding the first color solution, the second color solution, the first separation membrane, and the electrophoretic particles.

The first color solution may have a first density and the second color solution may have a second density that is greater than the first density.

The first separator may be formed by curing a first photo-curable solution having a density greater than the first density and a density less than the second density.

The first color solution may include a first solvent and a first dye dissolved in the first solvent and having the first color. The second color solution may include a second solvent and a second dye dissolved in the second solvent and having the second color. The first dye may be insoluble in the second solvent, and the second dye may be insoluble in the first solvent.

Wherein the microcapsule for electrophoretic display comprises a third color solution having a third color different from the first and second colors and a part of the electrophoretic particles being dispersed and a third color solution having a second color different from the first color and the second color, And a second separation membrane for separating the second color solution and the third color solution from each other.

The first color solution may have a first density, the second color solution may have a second density greater than the first density, and the third color solution may have a third density greater than the second density.

The second separation membrane may be formed by curing a second photocurable solution having a density greater than the second density and a density less than the third density.

The first color solution may include a first solvent and a first dye dissolved in the first solvent and having the first color. The second color solution may include a second solvent and a second dye dissolved in the second solvent and having the second color. The third color solution may include a third solvent and a third dye dissolved in the third solvent and having the third color. Wherein the first dye is insoluble in the second solvent and the third solvent, the second dye is insoluble in the first solvent and the third solvent, and the third dye is insoluble in the first solvent and the third solvent, 2 < / RTI > solvent.

The first color may be one of red, green, and blue, the second color may be another one of red, green, and blue, and the third color may be the other one of red, green, and blue.

Wherein the first color is one of cyan, magenta, and yellow, the second color is another one of cyan, magenta, and yellow, and the third color is one of cyan, magenta, The color may be one of cyan, magenta, and yellow.

An electrophoretic display device according to an aspect of the present invention includes a display layer including a plurality of pixel electrodes, a common electrode, and display cells arranged between the pixel electrodes and the common electrode. Wherein each of the display cells comprises a first color solution having a first color, a second color solution having a second color different from the first color, a second color solution having a second color different from the first color, And a first separating film for separating the second color solution from each other, and electrophoretic particles dispersed in the first color solution and the second color solution and charged with the first polarity.

The first color solution may have a first density and the second color solution may have a second density that is greater than the first density.

The first separator may be formed by curing a first photo-curable solution having a density greater than the first density and a density less than the second density.

The first separator may extend perpendicularly to the common electrode.

Wherein each of the display cells includes a third color solution having a third color different from the first and second colors and a part of the electrophoretic particles being dispersed and a second color solution having a second color different from the first color, And a second separation membrane for separating the two-color solution and the third color solution from each other.

The first color solution may have a first density, the second color solution may have a second density greater than the first density, and the third color solution may have a third density greater than the second density.

The second separation membrane may be formed by curing a second photocurable solution having a density greater than the second density and a density less than the third density.

The second separation membrane may extend parallel to the first separation membrane.

Each of the display cells may include a microcapsule having a capsule outer wall surrounding the first color solution, the second color solution, the first separation membrane, and the electrophoretic particles.

The display layer may include barrier ribs for separating the display cells from each other.

According to an aspect of the present invention, there is provided a method of manufacturing an electrophoretic display device, comprising: forming a first color solution having a first color and having a first density, a second color solution having a second color different from the first color, A first color curable solution having a density greater than the first density and a density less than the second density, and a second color curable solution dispersed in the first color solution and the second color solution, An indicator layer comprising microcapsules, each containing electrophoretic particles, is formed on the substrate. The substrate is disposed in parallel with the direction of the earth's center so that the first photocurable solution is perpendicularly extended between the first color solution and the second color solution by the density difference with respect to the substrate. Irradiating light onto the substrate arranged parallel to the direction of the center of the earth to cure the first photocurable solution so as to cure the first color solution and the second color solution between the first color solution and the second color solution, Are separated from each other.

Wherein each of the microcapsules has a third color solution having a third color different from the first and second colors and having a third density higher than the second density and a part of the electrophoretic particles being dispersed, And a second photocurable solution having a density greater than the first density and less than the third density.

Irradiating light onto the substrate arranged in parallel to the center of the earth to cure the second photo-curing solution to form a second color solution and a third color solution between the second color solution and the third color solution, A second separation membrane may be formed.

According to another aspect of the present invention, there is provided a method of manufacturing an electrophoretic display device, comprising: forming a first color solution having a first color and a first density, a second color solution having a second color different from the first color, An electrophoretic particle dispersed in the first color solution and charged in the second color solution and charged with a first polarity, and a photo-curing agent dispersed in the first color solution and the second color solution, A display layer is formed on the substrate. The substrate is disposed in parallel with the direction of the center of the earth so that the interface between the first color solution and the second color solution extends perpendicularly to the substrate by the density difference. Light is irradiated to the boundary between the first color solution and the second color solution of the substrate arranged parallel to the direction of the center of the earth using a mask exposing a boundary between the first color solution and the second color solution . A first separating film for separating the first color solution and the second color solution from each other is formed by curing the boundary portion between the first color solution and the second color solution using the light.

A barrier rib for separating the display cells from each other may be formed on the substrate.

Each of the display cells further includes a third color solution having a third color different from the first and second colors and having a third density greater than the second density and wherein a portion of the electrophoretic particles and the photo- can do.

The second color solution and the third color solution, and using the mask exposing the boundary between the first color solution and the second color solution and the boundary between the second color solution and the third color solution, Light may be irradiated to the boundary between the color solution and the third color solution. A second separating film for separating the second color solution and the third color solution from each other may be formed by curing the boundary portion between the second color solution and the third color solution using the light.

The electrophoretic display device and the microcapsule for an electrophoretic display device according to the present invention can be fabricated by a simple process while expressing three or more colors.

1 is a schematic cross-sectional view of an electrophoretic display device according to an embodiment of the present invention.
2 is a cross-sectional view of an indicator layer according to an embodiment of the present invention.
3 is a cross-sectional view of an indicator layer according to another embodiment of the present invention.
4 is a cross-sectional view of a display layer according to another embodiment of the present invention.
5 is a cross-sectional view of an indicator layer according to another embodiment of the present invention.
6A to 6C are views for explaining a method of controlling an electrophoretic display device according to an embodiment of the present invention.
7A to 7C are cross-sectional views illustrating a method of forming the display layer of FIG. 2 according to an embodiment of the present invention.
8A to 8C are cross-sectional views illustrating a method of forming the display layer of FIG. 4 according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art, and the following embodiments may be modified in various other forms, The present invention is not limited to the following embodiments. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an," and "the" include plural forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, regions and / or regions, it should be understood that these elements, components, regions, layers and / Do. These terms are not intended to be in any particular order, up or down, or top-down, and are used only to distinguish one member, region or region from another member, region or region. Thus, the first member, region or region described below may refer to a second member, region or region without departing from the teachings of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, embodiments of the present invention should not be construed as limited to any particular shape of the regions illustrated herein, including, for example, variations in shape resulting from manufacturing.

1 is a schematic cross-sectional view of an electrophoretic display device according to an embodiment of the present invention.

1, an electrophoretic display device 100 includes a plurality of pixel electrodes 120, a common electrode 150, and a display layer 140 between the pixel electrodes 120 and the common electrode 150 . The display layer 140 includes display cells arranged between the pixel electrodes 120 and the common electrode 150.

According to one example, the display cell may include the microcapsules 142 shown in Fig. 2 or the microcapsules 142a shown in Fig. According to another example, as shown in Figs. 4 and 5, the display cells 142b and 142c may be defined by the partition walls 143b and 143c. The display cells are described in more detail below with reference to Figures 2-5.

The electrophoretic display device 100 includes a lower substrate 110, pixel electrodes 120 arranged on the lower substrate 110, an adhesive layer 130 on the pixel electrodes 120, A display layer 140 on the layer 140, a common electrode 150 on the display layer 140, and an upper substrate 160 on the common electrode 150. According to one example, features such as characters or graphics displayed through the display layer 140 are viewed by the viewer in an upward direction through the top substrate 160. The shapes displayed through the display layer 140 may be viewed by the viewer in a downward direction through the lower substrate 110 or may be viewed through the upper substrate 160 and the lower substrate 110 in both directions And can be acknowledged by the viewer.

The lower substrate 110 may be a substrate made of various materials such as plastic. For example, the lower substrate 110 may be made of an insulating organic material, and may be formed of a material such as polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate polyethyeleneterephthalate (PET), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polycarbonate (PC) Cellulose triacetate (TAC), or the like, but is not limited thereto. The lower substrate 110 may be a flexible substrate which may be bent, curved or curled. According to another example, the lower substrate 110 may be a hard substrate made of a phenol-based or epoxy-based synthetic resin.

Although not shown in FIG. 1, a connection electrode (not shown) connected to the common electrode 150 is disposed on the lower substrate 110 through a penetrating electrode (not shown) penetrating through the display layer 140 . Wiring lines (not shown) connected to the pixel electrodes 120 and the connection electrode, and connection pads (not shown) connected to the wirings may be disposed on the lower substrate 110. A driving chip (not shown) may be mounted on the lower substrate 110 to provide driving voltages and a reference voltage to the pixel electrodes 120 and the connection electrodes through connection pads. The driving chip can apply an independent voltage to the pixel electrodes 120. [

The pixel electrodes 120 may have a single layer structure of copper, aluminum, indium tin oxide (ITO) or indium zinc oxide (IZO), or a single layer structure of copper, aluminum, ITO, Layer structure in which a layer of a second material such as nickel or gold is further laminated on the substrate.

The pixel electrodes 120 may be arranged on the lower substrate 110 to have various plan shapes and sizes according to the design. The pixel electrodes 120 are disposed apart from each other on the lower substrate 110. According to the design, some of the pixel electrodes 120 may be electrically connected to each other through wiring formed on the lower substrate 110.

The pixel electrodes 120 may be formed on the lower substrate 110 in a printing manner. The lower substrate 110 on which the pixel electrodes 120 are formed may be a printed circuit board. The pixel electrodes 120 may be formed on the lower substrate 110 using a roll-to-roll process. An active switching device using a semiconductor material, for example, a thin film transistor, may not be directly formed on the lower substrate 110.

The adhesive layer 130 may be disposed on the pixel electrodes 120 to provide an adhesive force so that the pixel electrodes 120 and the display layer 140 are bonded to each other. According to one example, the adhesive layer 130 may be formed using Pressure Sensitive Adhesive (PSA). The pressure sensitive adhesive may prevent changes in the optical properties of the components and may not require a curing process during the bonding process or a high temperature process during drying.

For example, the adhesive layer 130 may be made of an acrylic polymer, a silicone-based polymer, or a suitable polymer such as polyester, polyurethane, polyether, or synthetic rubber. The adhesive layer 130 can be melted by heat, and if it is melted by heat, it can have adhesiveness. The adhesive layer 130 may be cured by energy (e.g., heat or UV, etc.). According to another example, the adhesive layer 130 may not be cured according to the design. According to another example, the adhesive layer 130 may be a hot melt adhesive material that melts at a temperature of between about 80 degrees and about 120 degrees and is a sticky thermoplastic resin material.

The display layer 140 is disposed on the adhesive layer 130 and is positioned between the common electrode 150 and the pixel electrodes 120. The display layer 140 includes a plurality of pixel electrodes 120, Three or more colors may be displayed according to the direction and intensity of the electric field generated by the voltage application time or voltage application time.

The display layer 140 includes a first color separating the first color solution from the first color solution, a second color to the second color solution, a first separating membrane separating the first and second color solutions from each other between the first and second color solutions, And may include electrophoretic particles dispersed in the first color solution and the second color solution. The first color and the second color may be different from each other. The first color solution may have a first density and the second color solution may have a second density that is greater than the first density. The first separation membrane may be formed by curing the first photocurable solution having a density larger than the first density and a density smaller than the second density.

The electrophoretic particles may have a different color than the first and second colors. The electrophoretic particles can be charged to the first polarity to move in the direction of the applied electric field. According to another example, the electrophoretic particles may comprise first electrophoretic particles charged with a first polarity and second electrophoretic particles charged with a second polarity. At this time, the second polarity may be opposite to the first polarity. According to another example, the second polarity is the same polarity as the first polarity, but the charge amount and / or mass of the first electrophoretic particle may be different from the charge amount and / or mass of the second electrophoretic particle. At this time, the hue of the first electrophoretic particle and the hue of the second electrophoretic particle may be different from each other. In the following, it is assumed that one type of electrophoretic particles exists in the display layer 140. [ However, the present invention is not limited thereto.

According to one example, the display layer 140 may comprise microcapsules each comprising a first color solution, a second color solution, a first separation membrane, and electrophoretic particles. The display layer 140 may further include a binder to fix the microcapsules on the common electrode 150. The display layer 140 comprising microcapsules is described in more detail below with reference to Figures 2 and 3.

According to another example, the display layer 140 may have a mesh-shaped partition wall formed on the common electrode 150, and the display cells defined or divided by the partition walls may respectively include a first color solution, a second color solution, A first separation membrane and electrophoretic particles. The display layer 140, which includes display cells defined by barrier ribs, will be described in more detail below with reference to Figures 4 and 5.

The display layer 140 may display three or more colors depending on at least one of the direction of the electric field, the intensity, and the application time of the electric field. A control method for the display layer 140 to display three or more colors will be described in more detail below with reference to FIGS. 6A to 6C.

The common electrode 150 may be disposed entirely on the display layer 140 and positioned between the display layer 140 and the upper substrate 160. The common electrode 150 may be electrically connected to a connection electrode (not shown) on the lower substrate 110 through a penetrating electrode (not shown) penetrating the display layer 140 and the adhesive layer 130. When the electrophoretic display device 100 is operated, a reference voltage is applied to the common electrode 150 from the driving chip through the connection electrode and the penetrating electrode.

According to an example, the penetrating electrode may be formed of a liquid conductive material having a high viscosity. For example, the penetrating electrode may be formed using a silver paste, a carbon paste, or an electrically conductive liquid phase OCA (optically clear adhesive). According to another example, the penetrating electrode may be formed of a conductive adhesive film. According to another example, the penetrating electrode may be formed of a metal.

The common electrode 150 may be formed of a transparent conductive material such as ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), AZO (aluminum zinc oxide) and a transparent conductive oxide (ITO). The common electrode 150 may be formed entirely on the upper substrate 160 through a sputtering process. According to another example, the common electrode 150 may be formed over the entire surface of the upper substrate 160 through a coating process or a plating process.

The upper substrate 160 is a transparent transparent material disposed on the common electrode 150, and may be a film formed of a material having a high transmittance of 80% or higher. For example, the upper substrate 160 is a transparent polymer film having excellent light transmittance, and may be a transparent polymer film such as polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polycarbonate (PC), cellulose triacetate (TAC) and the like.

Although not shown in FIG. 1, a sealing portion (not shown) may be formed on a side surface of the electrophoretic display device 100. For example, the sealing portion may be disposed so as to surround at least the outer periphery of the display layer 140. The sealing portion can function as a main blocking film for preventing deformation of the display portion 150 from impurities such as oxygen and moisture.

According to one embodiment, the seal may comprise a photo-curable material that can be cured by irradiating light. The seal may comprise a mixture of an organic material and a photocurable material. The sealing portion can be formed by irradiating ultraviolet (UV) light, laser light, visible light, or the like and curing it. Examples of the photocurable material included in the sealing part include epoxy acrylate resin, polyester acrylate resin, urethane acrylate resin, polybutadine acrylate ) Based resin, a silicon acrylate based resin, an alkyl acrylate based resin, and the like. According to another embodiment, the sealing portion may be composed of a frit or the like.

2 is a cross-sectional view of an indicator layer according to an embodiment of the present invention.

Referring to FIG. 2, the display layer 140 may include microcapsules 142, and the microcapsules 142 may be fixed by a binder 141.

Each of the microcapsules 142 includes a first color solution 147 having a first color, a second color solution 148 having a second color different from the first color, a first separation membrane 145, (144) and a capsule outer wall (143). The first separation membrane 145 separates the first color solution 147 and the second color solution 148 from each other between the first color solution 147 and the second color solution 148. The electrophoretic particles 144 are dispersed in the first color solution 147 and the second color solution 148 and charged to the first polarity. The capsule outer wall 143 may surround the first color solution 147, the second color solution 148, the first separation membrane 145, and the electrophoretic particles 144 as shown in FIG. The first separating film 145 may be formed by curing the first photocurable solution and may be fixed to the capsule outer wall 143 while the first photocurable solution is cured.

Although the microcapsules 142 are shown as being arranged in a single layer in Fig. 2, they may be arranged in a plurality of layers. Also, although the microcapsules 142 are all shown to have the same size, they may have different sizes depending on the manufacturing process. The microcapsules 142 may be substantially spherical with a diameter between approximately several micrometers and several tens of micrometers. The pixel electrode 120 shown in FIG. 1 may have a width between approximately tens to several thousands of micrometers depending on the design. For example, several tens or more microcapsules 142 may be disposed on one pixel electrode 120.

The electrophoretic particles 144 are dispersed in the first color solution 147 and the second color solution 148. Electrophoretic particles 144 may be charged with a first polarity (e.g., (+) polarity or (-) polarity) so that they can move in the direction of the applied electric field. The electrophoretic particles 144 may absorb light or scatter light.

The electrophoretic particles 144 may comprise organic or inorganic compounds. The electrophoretic particles 144 may comprise a reflective material such as metal particles. The electrophoretic particles 144 may be particles that have been processed (e.g., coated) with a color-developing material having a unique color, such as a dye, a pigment, or the like. For example, the electrophoretic particles 144 may be at least one of iron (Fe), nickel (Ni), cobalt (Co), titanium (Ti), carbon (C), zinc (Zn) A material including elements such as silver (Ag), barium (Ba), strontium (Sr), lead (Pb), aluminum (Al), tungsten (W) and molybdenum (Mo) . In addition, the electrophoretic particles 144 can be particles that have been surface-treated with a dye or pigment, particles that have been surface-treated with an organic compound, particles that have been surface-treated with a complex compound, have.

The electrophoretic particles 144 may have a different hue than the first hue of the first color solution 147 and the second hue of the second color solution 148 and may be, for example, white, black, red, blue, Yellow, and the like. For example, the color of the electrophoretic particles 144 may be white. The white electrophoretic particles 144 may be formed by a method of surface-treating titanium dioxide particles to have electric charge, a surface treatment method of charging in a non-polar medium, a method of coating an oil / inorganic silane having a large electric capacity difference, A method of polymerizing a polymeric substance containing an inorganic material on the surface of an inorganic particle, and a method of depositing a polar inorganic material.

According to another embodiment, the electrophoretic particles 144 may comprise first electrophoretic particles charged with a first polarity and second electrophoretic particles charged with a second polarity. The first electrophoretic particles and the second electrophoretic particles may have different colors from each other. At this time, according to one example, the second polarity may be the opposite polarity of the first polarity. According to another example, the second polarity and the first polarity may be the same polarity to each other. In this case, the first electrophoretic particles and the second electrophoretic particles may have different physical and chemical properties such as surface charge, mass, shape and the like. For example, the first electrophoretic particles may be white and the second electrophoretic particles may be black. The second electrophoretic particles of black may be produced using organic / inorganic particles such as carbon black, iron oxide nanoparticles, copper chromate and the like.

The first color solution 147 and the second color solution 148 may include a solvent that allows the electrophoretic particles 144 to disperse and flow and may include water, methanol, ethanol, Propanol, butanol, propylene carbonate, toluene, benzene, hexane, chloroform, isoparaffin oil, silicone oil, ester Based oil, hydrocarbon oil, hydrocarbon oil, hydrocarbon oil, hydrocarbon oil tree, hexahanone, dimethicone, cetyloctanoate, dicaprylate, isopropyl myristate, tocophenol acetate and the like.

The first color solution 147 may be a first color and the second color solution 147 may be a second color. The first color and the second color are different colors, and may be selected differently from red, green, and blue according to an example. As another example, the first color and the second color may be selected differently from cyan, magenta, and yellow. According to one example, the first color solution 147 and the second color solution 148 may comprise different dye materials such as azo dyes, anthraquinone dyes, carbonium dyes, indigo dyes, sulfide dyes, phthalocyanine dyes, and the like have.

According to another example, the first color solution 147 and the second color solution 148 may separately include a fluorescent material, a phosphor, or a light emitting material. According to another example, the first color solution 147 and the second color solution 148 may include a color variable material (for example, a sion pigment material, a sion dye material, or the like) whose color characteristics change as energy is applied They may be included differently.

According to another example, the first color solution 147 and the second color solution 148 may be formed of titanium dioxide, zinc oxide, lithopone, zinc sulfide, An inorganic pigment such as carbon black, graphite, chrome yellow, fluorescent pigment and pearl pigment, or an inorganic pigment such as an insoluble azo pigment, a soluble azo pigment, a phthalocyanine pigment, a quinacridone pigment, a dioxazine pigment, , A tint dye system, a phyllocholine system, a fluorine system, a quinophthalone system, a metal complex, and the like.

The first color solution 147 may include a first solvent and a first dye dissolved in the first solvent. The second color solution 148 may include a second solvent and a second dye dissolved in the second solvent. The first dye may be selected as a material that causes the first color solution 147 to have a first color and the second dye may be selected as a material that causes the second color solution 148 to have a second color.

According to one example, the first color solution 147 and the second color solution 148 may be phase-separated from each other. The first solvent of the first color solution 147 and the second solvent of the second color solution 148 may be selected so as not to be mixed with each other. The first color of the first color solution 147 and the second color of the second color solution 148 are mixed so that the first color of the first color solution 147 and the second color of the second color solution 148 do not mix with each other, 2 solvent, and the second dye of the second color solution 148 may be selected as a material that is insoluble in the first solvent of the first color solution 147.

According to another example, the dissolution parameter of the first color solution 147 and the dissolution parameter of the second color solution 148 may be such that the same dye is not dissolved. For example, the first dye that matches the first dissolution parameter (e.g., 10) of the first solvent is dissolved in the first solvent to form the first color solution 147. The second color solution 148 is also formed by dissolving a second dye in the second solvent that is also matched with a second dissolution parameter (e.g., 20) of the second solvent. In order for the first dye and the second dye to dissolve in the first solvent and the second solvent, respectively, the dissolution parameters of the first dye and the second dye will be different from each other, and the first dye is dissolved only in the first solvent, May be dissolved only in the second solvent. The first color of the first color solution 147 and the second color of the second color solution 148 may not be mixed with each other.

The first color solution 147 may have a first density and the second color solution 148 may have a second density that is greater than the first density. During the manufacturing process of the microcapsules 142, the first color solution 147 is formed on the upper portion of the second color solution 148 by the difference in density between the first color solution 147 and the second color solution 148 Can be located. When the first color solution 147 and the second color solution 148 are phase-separated from each other, the first color solution 147 moves upward by gravity, and the second color solution 148 moves downward. The first solvent of the first color solution 147 and the second solvent of the second color solution 148 may be selected as a material having a density difference enough to be separated from each other.

For example, the Isopar M solvent has a density of 0.79 g / ml at 15 占 폚. The solvent of halocarbon oil 0.8 having polychlorotrifluoroethylene as a constituent has a density of 1.71 g / ml at 37.8 캜. The SC-PAR solvent having 1,2-dichloropropane as a constituent has a density of 1.16 g / ml at 20 占 폚. The SC-PAR solvent, which is a mixture of Nitroethane, 1-Nitropropane and 2-Nitropropane, has a density of 1.01 g / ml at 20 ° C. The first solvent of the first color solution 147 and the second solvent of the second color solution 148 may be selected from among the solvents having a density difference as described above.

The first separation membrane 145 separates the first color solution 147 and the second color solution 148 from each other between the first color solution 147 and the second color solution 148. The first separating film 145 may be formed by curing the first photocurable solution and may be fixed to the capsule outer wall 143 while the first photocurable solution is cured. The first separator 145 may extend perpendicularly to the common electrode 150 of FIG. 1 and may separate the first color solution 147 and the second color solution 148 vertically relative to the common electrode 150. can do. The first separation membrane 145 can separate the space within the capsule outer wall 143 approximately in half. Accordingly, the volume of the first color solution 147 and the volume of the second color solution 148 may be approximately equal to each other.

The first photocurable solution may be cured as light is irradiated from the outside from the outside, and may be larger than the first density of the first color solution 147 and smaller than the second density of the second color solution 148. The first photocurable solution may be a solution in which a solvent and a photocurable material are mixed.

The solvent of the first photocurable solution is at least one selected from the group consisting of water, methanol, ethanol, propanol, butanol, propylene carbonate, toluene, benzene, hexane, chloroform, isoparaffin oil, silicone oil, ester oil, Dimethicone, cetyl octanoate, dicaprylate, isopropyl myristate, tocophenol acetate, and the like. The solvent of the first photo-curable solution may be selected as a material that does not mix with the first solvent of the first color solution 147 and the second solvent of the second color solution 148. Further, the solvent of the first photocurable solution may be selected as a material which is larger in density than the first solvent of the first color solution 147 and smaller than the second solvent of the second color solution 148.

The first photocurable solution may contain 10 wt% or more and 100 wt% or less of the photocurable material. The density of the first photocurable solution may be adjusted to be greater than the first density of the first color solution 147 and less than the second density of the second color solution 148 by adjusting the amount of the photocurable material.

The first color solution 147, the second color solution 148, the first photo-curable solution, and the electrophoretic particles 144 may be mixed to form an emulsion. The emulsion may have a diameter of 1 탆 or more and 1000 탆 or less, which is a mixing ratio between the first color solution 147, the second color solution 148, the first photocurable solution and the electrophoretic particles 144, And the like. The emulsion thus formed can be encapsulated. The capsule outer wall 143 may surround the emulsion in which the first color solution 147, the second color solution 148, the first photo-curable solution, and the electrophoretic particles 144 are mixed. The first photocurable solution may be deformed into a first separation membrane 145 which is cured and fixed to the capsule outer wall 143.

The capsule outer wall 143 surrounding the emulsion may be made of a light transmitting polymer material, for example, aginate, gelatin, ethyl cellulose, polyamide, melamine-formaldehyde such as melamine formaldehyde, poly (vinyl pyridine), polystyrene, urethane, polyurethane, methylmethacrylate, and the like.

According to one example, the capsule outer wall 143 may be formed by, for example, in-situ polymerization. As the molecular weight of the monomers dissolved in the aqueous solution is increased, the oligomer or polymer is located at the interface between the organic phase and the aqueous phase which have been emulsified. As a result, the polymer at the interface has a larger molecular weight through the cross- 143)

According to another example, the capsule outer wall 143 may be formed using an isoelectric point by a coacervation microencapsulation method. And the capsule outer wall 143 may be formed by a method such as emulsion polymerization, multiple emulsion polymerization, condensation polymerization, solvent extraction and evaporation, suspension polymerization, coacervation, extrusion, spraying and the like have.

The capsule outer wall 143 may be cured by high temperature conditions, low temperature conditions, ionic conditions, etc., and may have soft or hard characteristics depending on the concentration or type of the polymer contained in the capsule outer wall 143 .

After the capsule outer wall 143 is formed, the emulsion in the capsule outer wall 143 separates according to the characteristics and the density of the first color solution 147, the first photo-curable solution, and the second color solution 148 over time . As a result, as shown in FIGS. 7A and 7B, the first color solution 147 is located in the upper region of the capsule outer wall 143, the second color solution 148 is located in the lower region, The first photocurable solution is positioned between the first color solution 147 and the second color solution 148. [ When the display layer 140 is vertically set so that the display layer 140 extends in a direction parallel to the center of the earth and the first photocurable solution is irradiated with light such as ultraviolet light, The first separation membrane 145 is formed between the two color solutions 148. The first separation membrane 145 may be fixed to the capsule outer wall 143 by separating the first color solution 147 and the second color solution 148 from each other. The electrophoretic particles 144 dispersed in the first color solution 147 can be moved by the electric field applied in the first color solution 147. [ The electrophoretic particles 144 dispersed in the second color solution 148 can be moved by the electric field applied in the second color solution 148. The method of manufacturing the microcapsules 142 will be described in more detail below with reference to Figs. 7A to 7C.

The binder 141 may comprise an at least partially transparent material in the visible light region of 380 nm to 750 nm. The binder 141 may include at least one transparent polymer material selected from the group consisting of an acrylic polymer, a silicone polymer, an ester polymer, a urethane polymer, an amide polymer, an ether polymer, a fluorine polymer and rubber. According to another example, the binder 141 may include a fluorescent material, a phosphorescent material, a light emitting material, or the like, or may include a material (for example, a sion pigment material, a sion dye material, etc.) have. The binder 141 may be in a cured state.

3 is a cross-sectional view of an indicator layer according to another embodiment of the present invention.

Referring to FIG. 3, the display layer 140a may include microcapsules 142a, and the microcapsules 142a may be fixed by a binder 141a. The binder 141a is substantially the same as the binder 141 described with reference to Fig. 2, and will not be repeatedly described.

Each of the microcapsules 142a includes a first color solution 147a of a first color, a second color solution 148a of a second color, a third color solution 149a of a third color, a first separation membrane 145a, A second separation membrane 146a, electrophoretic particles 144a, and a capsule outer wall 143a. The electrophoretic particles 144 are dispersed in the first to third color solutions 147a, 148a, 149a, and charged to the first polarity. The capsule outer wall 143a may surround the first to third color solutions 147a, 148a and 149a, the first and second separation membranes 145a and 146a and the electrophoretic particles 144a. The first separation membrane 145a separates the first color solution 147a and the second color solution 148a from each other between the first color solution 147a and the second color solution 148a. The second separation membrane 146a separates the second color solution 148a and the third color solution 149a from each other between the second color solution 148a and the third color solution 149a.

The microcapsules 142a correspond to the microcapsules 142 of FIG. 2, and differences will be mainly described below. The electrophoretic particles 144a and the capsule outer wall 143a are substantially identical to the electrophoretic particles 144 and the capsule outer wall 143 of FIG. 2 and are not repeatedly described herein. The first color solution 147a and the second color solution 148a correspond to the first color solution 147 and the second color solution 148 in FIG. 2, and the difference will be mainly described below.

The first to third color solutions 147a, 148a, and 149a include a solvent that allows the electrophoretic particles 144a to disperse and flow. The first color solution 147a may include a first solvent and a first dye dissolved in the first solvent. The second color solution 148a may include a second solvent and a second dye dissolved in the second solvent. The third color solution 149a may include a third solvent and a third dye dissolved in the third solvent.

The first to third color solutions 147a, 148a, and 149a may be phase-separated from each other. The first to third solvents of the first to third color solutions 147a, 148a, and 149a may be selected so as not to be mixed with each other.

The first color of the first color solution 147a, the second color of the second color solution 148a, and the third color of the third color solution 149a may all be different from each other. For example, the first to third colors may constitute three primary colors. For example, the first to third colors may be selected differently from red, green, and blue, respectively. As another example, the first to third hues may be selected differently from cyan, magenta, and yellow, respectively. The electrophoretic particles 144a may have a different hue than the first through third hues, and may be, for example, white. The first dye is selected as a material that causes the first color solution 147a to have a first hue and the second dye is selected as a material that causes the second color solution 148a to have a second hue, The third color solution 149a may be selected as a material having a third color. For example, the first to third dyes of the first to third color solutions 147a, 148a, and 149a may be formed of a dye material such as an azo dye, an anthraquinone dye, a carbonium dye, an indigo dye, a sulfide dye, a phthalocyanine dye, Can be selected differently.

According to one example, the first dye of the first color solution 147a is mixed with the second color solution 147a so that the first to third colors of the first to third color solutions 147a, 148a, 148a and the third color solution 149a is selected as a material insoluble in the third solvent and the second dye of the second color solution 148a is selected as the first solvent of the first color solution 147a And the third dye solution of the third color solution 149a is selected as a material which is insoluble in the third solvent of the third color solution 149a and the third solvent of the second color solution 149a, 148a may be selected as a material insoluble in the second solvent.

According to another example, the dissolution parameters of the first to third color solutions 147a, 148a, 149a may be such that the same dye is not dissolved in two or more solvents. For example, when the dissolution parameter of the first dye is matched with the dissolution parameter (e.g., 10) of the first solvent, the first dye is dissolved in the first solvent to form the first color solution 147a. When the dissolution parameter of the second dye is matched with the dissolution parameter (e.g., 20) of the second solvent, the second dye is dissolved in the second solvent to form the second color solution 148a. When the dissolution parameter of the third dye is matched with the dissolution parameter (e.g., 30) of the third solvent, the third dye is dissolved in the third solvent to form the third color solution 149a. Thus, when the dissolution parameters of the first to third color solutions 147a, 148a, and 149a are different from each other, the first dye is dissolved only in the first solvent, the second dye is dissolved only in the second solvent, May be dissolved only in the third solvent. As a result, the first to third colors of the first to third color solutions 147a, 148a, and 149a may not be mixed with each other.

The first color solution 147a has a first density, the second color solution 148a has a second density that is greater than the first density, and the third color solution 149a has a third density that is greater than the second density Lt; / RTI > During the manufacturing process of the microcapsules 142a, the first to third color solutions 147a, 148a, and 149a are stacked on each other due to the difference in density of the first to third color solutions 147a, 148a, . The first to third solvents of the first to third color solutions 147a, 148a, and 149a may be selected as a material having a density difference enough to be separated from each other.

The first separation membrane 145a separates the first and second color solutions 147a and 148a from each other between the first and second color solutions 147a and 148a and the second separation membrane 146a separates the first and second color solutions 147a and 148b from the second and third color solutions 147a and 148a, And separates the second and third color solutions 148a and 148a from each other between the third color solutions 148a and 148a.

The first separating film 145a may be formed by curing the first photocurable solution, and may be fixed to the capsule outer wall 143a while curing the first photocurable solution. In addition, the second separation membrane 146a may be formed by curing the second photocurable solution, and may be fixed to the capsule outer wall 143a while the second photocurable solution is cured.

The first separator 145a and the second separator 146a may extend perpendicularly to the common electrode 150 of FIG. 1 and the first to third color solutions 147a, 148a, 150). ≪ / RTI > The first separation membrane 145a and the second separation membrane 146a can separate the space in the capsule outer wall 143 by approximately one third. Accordingly, the volumes of the first to third color solutions 147a, 148a, and 149a may be substantially equal to each other. According to another example, the first separation membrane 145a and the second separation membrane 146a are disposed in the capsule outer wall 143 such that the areas of the horizontal cross sections of the first to third color solutions 147a, 148a, and 149a are equal to each other .

The first and second photocurable solutions may be cured as light is irradiated from the outside, such as ultraviolet rays, or may be a solution in which a solvent and a photocurable material are mixed. The first photocurable solution may be greater than the first density of the first color solution 147a and less than the second density of the second color solution 148a. The second photocurable solution may be greater than the second density of the second color solution 148a and less than the third density of the third color solution 149a. Accordingly, when the microcapsules 142a are formed, the first separating film 145a formed by curing the first photocurable solution separates them between the first and second color solutions 147a and 148a, The second separation membrane 146a, which is formed by curing the second photocurable solution, can separate them between the second and third color solutions 148a and 149a.

The solvents of the first and second photocurable solutions may be selected not to be mixed with each other but to be immiscible with the first to third solvents of the first to third color solutions 147a, 148a and 149a. Further, the solvent of the first photocurable solution may be selected as a material that is larger than the density of the first solvent of the first color solution 147a and smaller than the second solvent of the second color solution 148a. The solvent of the second photocurable solution may be selected as a material that is larger than the density of the second solvent of the second color solution 148a and smaller than the third solvent of the third color solution 149a.

The first and second photocurable solutions may each contain 10 wt% or more and 100 wt% or less of a photocurable material. By adjusting the amount of the photocurable material contained in the first and second photocurable solutions, the density of the first and second photocurable solutions can be controlled.

The first to third color solutions 147a, 148a, 149a, the first and second photo-curable solutions, and the electrophoretic particles 144a are mixed to form an emulsion, and the emulsion can be encapsulated. The capsule outer wall 143a formed by encapsulation may surround the emulsion. As the emulsion is irradiated with light, the first and second photocurable solutions can be cured to the first and second separation membranes 145a and 146a.

4 is a cross-sectional view of a display layer according to another embodiment of the present invention.

Referring to Fig. 4, the display layer 140b includes barrier ribs 143b and display cells 142b defined by barrier ribs 143b. The display layer 140b is disposed between the common electrode 150 and the adhesive layer 130 like the display layer 140 shown in Fig.

A partition wall 143b for physically partitioning the display cells 142b may be disposed on the common electrode 150 or between the common electrode 150 and the adhesive layer 130. [ The barrier ribs 143b may be arranged in a mesh form or a lattice form on a plane.

The barrier ribs 143b may be formed of a resin such as an organic compound or an inorganic compound, or a combination thereof. For example, the partition 143b may be formed of a sealing material, and may be formed of, for example, an UV-curable acrylic resin or a thermosetting epoxy-based resin. According to one example, the barrier ribs 143b may be formed in a stamper manner to imprint the resin layer after forming the resin layer. According to another example, the partition 143b may be formed using a photolithographic process. For example, after a photosensitive resin layer is coated on the common electrode 150, a light is irradiated to a position where the partition 143b is to be formed or a position to be removed for forming the partition 143b using a photomask, The partition wall 143b can be formed through the process.

The electrophoretic particles 144b, the first color solution 147b, the second color solution 148b, and the first separation membrane 145b may be disposed in a space defined by the partition wall 143b. The first separation membrane 145b can separate them from each other between the first and second color solutions 147b and 148b. The electrophoretic particles 144b may flow in the first and second color solutions 147b and 148b and may move in accordance with the direction and intensity of the electric field specifically applied. The electrophoretic particles 144b, the first color solution 147b, the second color solution 148b, and the first separation layer 145b may constitute one display cell 142b. The electrophoretic particles 144b, the first color solution 147b, and the second color solution 148b are the same as the electrophoretic particles 144, the first color solution 147, And the second color solution 148, respectively, and the description thereof will not be repeated, but the differences will be mainly described.

The first color solution 147b and the second color solution 148b may include a light curable material that can be cured by light such as ultraviolet light. The first coloring material 147b and the second coloring material 148b may be formed by locally irradiating the boundary portion between the first coloring solution 147b and the second coloring solution 148b using a mask, The first color solution 147b and the remaining portions of the second color solution 148b may be separated from each other.

5 is a cross-sectional view of an indicator layer according to another embodiment of the present invention.

Referring to Fig. 5, the display layer 140c includes barrier ribs 143c and display cells 142c defined by barrier ribs 143c. The display layer 140c is disposed between the common electrode 150 and the adhesive layer 130 like the display layer 140 shown in FIG.

A partition 143c for physically partitioning the display cells 142c may be disposed on the common electrode 150 or between the common electrode 150 and the adhesive layer 130. [ The barrier ribs 143c may be arranged on a plane in a mesh form or a lattice form. The partition 143c is substantially the same as the partition 143b in Fig. 4, and this will not be repeatedly described.

The electrophoretic particles 144c, the first to third color solutions 147c, 148c, and 149c, and the first and second separation membranes 145c and 146c may be disposed in a space defined by the partition wall 143c . The first separation membrane 145c may separate them from each other between the first and second color solutions 147b and 148c and the second separation membrane 146c may separate the first and second color solutions 147b and 148c between the second and third color solutions 148c and 149 They can be separated from each other.

The electrophoretic particles 144c, the first to third color solutions 147c, 148c and 149c and the first and second separation membranes 145c and 146c may constitute one display cell 142c. The electrophoretic particles 144c and the first to third color solutions 147c, 148c and 149c correspond to the electrophoretic particles 144a and the first to third color solutions 144a, (147a, 148a, and 149a), respectively, and the description thereof will not be repeated, and differences will be mainly described.

The first to third color solutions 147c, 148c, and 149c may include a light curable material that can be cured by light such as ultraviolet light. The first and second separation membranes 145c and 146c are formed on the boundary portion between the first and second color solutions 147c and 148c and the boundary portion between the second and third color solutions 148c and 149c using a mask Can be formed to separate the first and second color solutions 147c and 148c from each other and to separate the second and third color solutions 148c and 149c from each other by locally irradiating light.

6A to 6C are views for explaining a method of controlling an electrophoretic display device according to an embodiment of the present invention.

Referring to FIG. 6A, microcapsules 142 positioned between the common electrode 150 and the pixel electrodes 120 are shown. The microcapsules 142 may display three or more colors depending on the driving voltages Va, Vb, Vc, and Vd applied to the lower pixel electrodes 120. [ The display layer 140 shown in FIG. 1 includes the microcapsules 142 shown in FIG. 6A, and can display a color corresponding to a driving voltage applied to the pixel electrode 120. A plurality of microcapsules 142 are disposed on the pixel electrodes 120. In order to facilitate understanding of the present invention, one microcapsule 142 is disposed on each of the pixel electrodes 120, do. It should also be appreciated that although the microcapsules 142 of FIG. 2 are shown in FIG. 6A, the display cells 142b of FIG. 4 can also display more than three colors in the same manner.

The common electrode 150 is grounded or a reference voltage is applied and the first to fourth driving voltages V1 to Vn are applied to the pixel electrodes 120 in order to change the display state of the display layer 140 or the display color of the microcapsules 142. [ (Va, Vb, Vc, Vd) are applied. As described above, the microcapsules 142 include a capsule outer wall 143, electrophoretic particles 144, a first color solution 147, a second color solution 148, and a first separation membrane 145 .

Referring to FIG. 6A, when the first driving voltage Va is applied to the pixel electrode 120, the electrophoretic particles 144 are moved toward the common electrode 150. Accordingly, the microcapsules 142 display the color of the electrophoretic particles 144 in the direction of the common electrode 150. For example, when the color of the electrophoretic particles 144 is white, the microcapsules 142 on the pixel electrode 120 to which the first driving voltage Va is applied display white. If the color of the electrophoretic particles 144 is black, the microcapsules 142 on the pixel electrode 120 to which the first driving voltage Va is applied display black.

When the second driving voltage Vb is applied to the pixel electrode 120, the electrophoretic particles 144 move toward the pixel electrode 120. Accordingly, the microcapsules 142 display the mixed color of the first color of the first color solution 127 and the second color of the second color solution 128 in the direction of the common electrode 150. That is, the microcapsules 142 on the pixel electrode 120 to which the second driving voltage Vb is applied display the mixed color of the first color and the second color.

When the third driving voltage Vc is applied to the pixel electrode 120, the electrophoretic particles 144 in the first color solution 127 move toward the common electrode 150, The electrophoretic particles 144 are moved toward the pixel electrode 120. Accordingly, the microcapsules 142 display the mixed color of the electrophoretic particles 144 and the second color of the second color solution 128 in the direction of the common electrode 150. That is, the microcapsules 142 on the pixel electrode 120 to which the third driving voltage Vc is applied displays the mixed color of the electrophoretic particles 144 and the second color. When the color of the electrophoretic particles 144 is black, the microcapsules 142 on the pixel electrode 120 to which the third driving voltage Vc is applied will display a second color and the electrophoretic particles 144 144 are white, the microcapsules 142 on the pixel electrode 120 to which the third driving voltage Vc is applied will display the mixed color of the second color and the white color.

When the fourth driving voltage Vd is applied to the pixel electrode 120, the electrophoretic particles 144 in the first color solution 127 move toward the pixel electrode 120, The electrophoretic particles 144 within the electrophoretic particles 144 move toward the common electrode 150. Accordingly, the microcapsules 142 display the mixed color of the first color of the first color solution 127 and the color of the electrophoretic particles 144 in the direction of the common electrode 150. That is, the microcapsules 142 on the pixel electrode 120 to which the fourth driving voltage Vd is applied display the mixed color of the first color and the electrophoretic particles 144. When the color of the electrophoretic particles 144 is black, the microcapsules 142 on the pixel electrode 120 to which the fourth driving voltage Vd is applied will display a first color and the electrophoretic particles 144 144 are white, the microcapsules 142 on the pixel electrode 120 to which the fourth driving voltage Vd is applied will display the mixed color of the first color and the white color.

Before describing the first to fourth driving voltages Va, Vb, Vc, and Vd applied to the pixel electrode 120 to display the four different colors of the microcapsules 142 as described above, The phenomenon that the electrophoretic particles in the electrophoretic particles migrate by the electric field will be described first.

The electrophoretic particles bearing the electric field (E) applied in the solution move in the solution at a velocity (v) proportional to the applied electric field (E) as shown in the following equation (1).

[Equation 1]

v =? E

Here, μ is a proportional constant, which means electrophoretic mobility. The electrophoretic mobility (μ) can be expressed as:

[Equation 2]

μ = ζε / η

Where ε is the dielectric constant of the solution, η is the viscosity of the solution, and ζ is the zeta potential of the solution. The zeta potential refers to the electrostatic potential in a shear plane surrounding charged electrophoretic particles and can be expressed as Equation 3 below.

[Equation 3]

ζ = gλ _D / ε

Here, g is the charge amount of the electrophoretic particles, and _D is the debye length of the electrophoretic particles in the solution. Therefore, when the cell height is h, the switching time (t _total ) of the electrophoretic particles moving at the speed (v) can be quantified by the following equation (4). Here, V is an applied voltage, and the electric field E is defined as a value (V / h) obtained by dividing the driving voltage V by the cell height h.

[Equation 4]

_{t total h / v = h /} μE = h 2 / μV

That is, when the driving voltage V is applied for the switching time t _total , the electrophoretic particles move in the solution by the cell height h, and the display color of the display layer changes completely. If the driving voltage V is applied by half of the switching time (t _total / 2), the electrophoretic particles move by half (h / 2) of the cell height in the solution. When the voltage V / 2 of half the driving voltage V is applied for the switching time ttotal, the electrophoretic particles move by half of the cell height in the solution by h / 2.

Since the first color solution 147 and the second color solution 148 are different from each other, the electrophoretic mobility for the electrophoretic particles 144 is also different from each other. For example, the electrophoretic mobility of the first color solution 147 with respect to the electrophoretic particles 144 is referred to as a first electrophoretic mobility μ 1, and the electrophoretic particles 144 of the second color solution 148 ) Is referred to as a second electrophoretic mobility (2). At this time, it is assumed that the first electrophoretic mobility (1) is larger than the second electrophoretic mobility (2).

In this case, in order to move the electrophoretic particles 144 in the first color solution 147 to the unit time tu by the cell height h, the first driving voltage V1 must be applied to the pixel electrode 120 In order to move the electrophoretic particles 144 in the second color solution 148 to the unit time tu by the cell height h, the second driving voltage V2, which is larger than the first driving voltage V1, Must be applied to the pixel electrode (120). When the unit driving voltage Vu is applied to the pixel electrode 120, the electrophoretic particles 144 in the first color solution 147 move by the cell height h, And when the unit driving voltage Vu is applied to the pixel electrode 120, the electrophoretic particles 144 in the second color solution 148 move for a first time t1 when the electrophoretic particles 144 move by the cell height h, A longer second time t2 is required.

Assume that electrophoretic particles 144 are charged with positive charge. 6B and 6C, 'lower' refers to the direction of the pixel electrode 120, and 'upper' refers to the direction of the common electrode 150.

6B shows an example of the first to fourth driving voltages for making the state of the microcapsules 142 as shown in FIG. 6A.

Referring to FIG. 6B, the first driving voltage Va may be a second driving voltage V2 applied for a unit time tu. Since the first electrophoretic mobility μ1 is larger than the second electrophoretic mobility μ2, the second driving voltage V2 is larger than the first driving voltage V1, When the electrophoretic particles 144 move down (i.e., in the direction of the pixel electrode 120) (i.e., in the direction of the common electrode 150), the electrophoretic particles 147 in the first color solution 147 144 are all moved from below to above. Therefore, the electrophoretic particles 144 in the microcapsules 142 all move upward. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the first driving voltage Va is applied display the color of the electrophoretic particles 144.

The second driving voltage Vb may be a negative second driving voltage -V2 applied for a unit time tu. Since the first electrophoretic mobility μ1 is larger than the second electrophoretic mobility μ2, the magnitude of the second driving voltage V2 is larger than the magnitude of the first driving voltage V1, When the electrophoretic particles 144 in the first color solution 147 move from top to bottom, all of the electrophoretic particles 144 in the first color solution 147 also move up and down. Therefore, the electrophoretic particles 144 in the microcapsules 142 are all moved downward. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the second driving voltage Vb is applied display the mixed color of the first color and the second color.

The third driving voltage Vc may be a first driving voltage V1 applied for a unit time tu. It is assumed that the electrophoretic particles 144 in the microcapsules 142 are all located below before the third drive voltage Vc is applied. When the first driving voltage V1 is applied to the pixel electrode 120 during the unit time tu, the electrophoretic particles 144 in the first color solution 147 move from the bottom up to the cell height h . However, the electrophoretic particles 144 in the second color solution 148 can not move by the cell height h. The electrophoretic particles 144 in the second color solution 148 need a second driving voltage V2 to move by the cell height h. In addition, when the first driving voltage V1 is less than the threshold voltage for the electrophoretic particles 144 of the second color solution 148, the electrophoretic particles 144 in the second color solution 148 are lower Or moves slightly upward. The threshold voltage is the voltage at which the electrophoretic particles begin to move so as to change the display state. As a result, when the third driving voltage Vc is applied to the pixel electrode 120, the electrophoretic particles 144 in the first color solution 147 are positioned on the second color solution 147 The electrophoretic particles 144 within the electrophoretic particles 148 are positioned below. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the third driving voltage Vc is applied display the color of the electrophoretic particles 144 mixed with the second color.

The fourth driving voltage Vd is a negative first driving voltage -V1 applied from the second driving voltage V2 applied up to the unit time tu to the second unit time tu from the unit time tu, Lt; / RTI > It is assumed that the electrophoretic particles 144 in the microcapsules 142 are all located below before the fourth drive voltage Vd is applied. The electrophoretic particles 144 in the first color solution 147 and the electrophoretic particles 147 in the second color solution 147 are supplied to the pixel electrode 120 during the unit time (tu) All of the particles move from bottom to top. Thereafter, when a negative first driving voltage V1 is applied to the pixel electrode 120 for a unit time tu, the electrophoretic particles 144 in the first color solution 147 are moved to the cell height h, while the electrophoretic particles 144 in the second color solution 148 are unable to move completely down and remain on. In addition, when the magnitude of the first driving voltage V1 is smaller than the magnitude of the threshold voltage for the electrophoretic particles 144 of the second color solution 148, the electrophoretic particles in the second color solution 148 144 move up or down slightly. As a result, when the fourth driving voltage Vd is applied to the pixel electrode 120, as shown in FIG. 6A, the electrophoretic particles 144 in the first color solution 147 are positioned below, The electrophoretic particles 144 in the electrophoretic medium 148 are placed on top. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the fourth driving voltage Vd is applied display the color of the electrophoretic particles 144 mixed with the first color.

6C shows an example of the first to fourth driving voltages for making the state of the microcapsules 142 as shown in FIG. 6A.

Referring to FIG. 6C, the first driving voltage Va may be a unit driving voltage Vu applied during the second time t2. The second time t2 is longer than the first time t1 and the second electrophoretic mobility μ1 is greater than the second electrophoretic mobility μ2 because the first electrophoretic mobility μ1 is greater than the second electrophoretic mobility μ2, All of the electrophoretic particles 144 in the first color solution 147 are also moved upward from below. Therefore, the electrophoretic particles 144 in the microcapsules 142 all move upward. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the first driving voltage Va is applied display the color of the electrophoretic particles 144.

The second driving voltage Vb may be a negative unit driving voltage -Vu applied during the second time t2. The second time t2 is longer than the first time t1 and the second electrophoretic mobility μ1 is greater than the second electrophoretic mobility μ2 because the first electrophoretic mobility μ1 is greater than the second electrophoretic mobility μ2, All of the electrophoretic particles 144 in the first color solution 147 are also moved from top to bottom. Therefore, the electrophoretic particles 144 in the microcapsules 142 are all moved downward. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the second driving voltage Vb is applied display the mixed color of the first color and the second color.

The third driving voltage Vc may be a unit driving voltage Vu applied for the first time t1. It is assumed that the electrophoretic particles 144 in the microcapsules 142 are all located below before the third drive voltage Vc is applied. When the unit driving voltage Vu is applied to the pixel electrode 120 for the first time t1, the electrophoretic particles 144 in the first color solution 147 move from the bottom up to the cell height h . However, the electrophoretic particles 144 in the second color solution 148 can not move by the cell height h. This is because the electrophoretic particles 144 in the second color solution 148 require a second time t2 to move by the cell height h. In addition, if the first time t1 is shorter than the response time for the electrophoretic particles 144 of the second color solution 148, the electrophoretic particles 144 in the second color solution 148 will be below It will not move or move up slightly. Response time refers to the time at which the electrophoretic particles begin to move to such a degree that they can change the display state. As a result, when the third driving voltage Vc is applied to the pixel electrode 120, the electrophoretic particles 144 in the first color solution 147 are positioned on the second color solution 147 The electrophoretic particles 144 within the electrophoretic particles 148 are positioned below. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the third driving voltage Vc is applied display the color of the electrophoretic particles 144 mixed with the second color.

The fourth driving voltage Vd is a unit driving voltage Vu applied during the second time t2 and a negative unit driving voltage Vd applied during the time between the second time t2 and the third time t2 + (-Vu). It is assumed that the electrophoretic particles 144 in the microcapsules 142 are all located below before the fourth drive voltage Vd is applied. When the unit driving voltage Vu is applied to the pixel electrode 120 for the second time t2, the electrophoretic particles 144 in the first color solution 147 and the electrophoretic particles 147 in the second color solution 147 All of the particles move from bottom to top. Thereafter, when a negative unit driving voltage Vu is applied to the pixel electrode 120 for the first time t1, the electrophoretic particles 144 in the first color solution 147 are moved to the cell height h, while the electrophoretic particles 144 in the second color solution 148 are unable to move completely down and remain on. As a result, when the fourth driving voltage Vd is applied to the pixel electrode 120, as shown in FIG. 6A, the electrophoretic particles 144 in the first color solution 147 are positioned below, The electrophoretic particles 144 in the electrophoretic medium 148 are placed on top. Accordingly, the microcapsules 142 on the pixel electrode 120 to which the fourth driving voltage Vd is applied display the color of the electrophoretic particles 144 mixed with the first color.

6A to 6C, a method of adjusting the display color of the microcapsules 142 of FIG. 2 is described. However, the microcapsules 142a of FIG. 3 and the display cells of FIG. 5 including three kinds of color solutions 142c), the display color can be adjusted in a similar manner.

7A to 7C are cross-sectional views illustrating a method of forming the display layer of FIG. 2 according to an embodiment of the present invention.

Referring to FIG. 7A, the display layer 140 'includes a binder 141 for fixing the microcapsules 142' and the microcapsules 142 '. FIG. 7A shows a section parallel to the center of the earth, and the downward direction in FIG. 7A corresponds to the direction of the center of the earth. The display layer 140 'is for forming the display layer 140 of FIG. The display layer 140 'may be formed on the common electrode 150 on the upper substrate 150. According to another example, the display layer 140 'may be bonded between the common electrode 150 on the upper substrate 150 and the pixel electrodes 120 of the lower substrate 110 by the adhesive layer 130 .

The microcapsules 142 'include a first color solution 147', a second color solution 148 ', and a first photo-curable solution 145'. Although not shown in FIG. 7A, the microcapsules 142 'include electrophoretic particles 144 as shown in FIG. The first color solution 147 'and the second color solution 148' are substantially the same as the first color solution 147 and the second color solution 148 of FIG. 2, and the first color solution 147 ' Is substantially the same as the first photocurable solution described in the description of the embodiment of Fig.

The density of the first color solution 147 'is less than the density of the first photo-curable solution 145' and the density of the first photo-curable solution 145 'is less than the density of the second color solution 148'. As a result, as shown in FIG. 7A, when the display layer 140 'is placed perpendicular to the direction of the center of the earth, the second color solution 148' is positioned below and the first color solution 147 ' And the first photocurable solution 145 'is positioned between the first color solution 147 and the second color solution 148.

Referring to FIG. 7B, the display layer 140 'is vertically erected. That is, the display layer 140 'is disposed so as to extend in a direction parallel to the direction of the center of the earth. As a result, as shown in FIG. 7B, the first color solution 147 ', the first photo-curable solution 145', and the second color solution 148 'are laminated in the direction of the center of the earth. In this state, the first photocurable solution 145 'spreads perpendicularly to the direction of the center of the earth, and extends perpendicularly to the extending direction of the display layer 140'. Thus, light such as ultraviolet rays is irradiated onto the first photocurable solution 145 'extending perpendicular to the extending direction of the display layer 140'. The first photocurable solution 145 'is cured to the state shown in FIG. 7B to be fixed to the capsular outer wall 143 and is capable of separating the first color solution 147' and the second color solution 148 ' have.

Referring to FIG. 7C, the first photocurable solution 145 'is cured to form a first separation layer 145 extending in a direction perpendicular to the extending direction of the display layer 140. The first coloring solution 147 and the second coloring solution 148 are vertically separated as shown in FIG. 7C, and the first coloring solution 147 and the second coloring solution 148 are separated vertically . As a result, both the first color solution 147 and the second color solution 148 are seen in the direction of the common electrode 150. [

In the same manner, the microcapsules 142a of Fig. 3 can also be formed.

Referring to FIG. 3, an indicator layer 140 including microcapsules encapsulating an emulsion may be formed on the upper substrate 160. At this time, the microcapsules include first to third color solutions 147a, 148a, 149a, first and second photo-curable solutions, and electrophoretic particles 144a.

The first color solution 147a has a first density, the second color solution 148a has a second density that is greater than the first density, and the third color solution 149a has a third density that is greater than the second density . The first photocurable solution has a density between the first density and the second density, and the second photocurable solution has a density between the second density and the third density. The electrophoretic particles 144a are dispersed in the first to third color solutions 147a, 148a and 149a.

The upper substrate 160 is arranged parallel to the direction of the earth's center, i.e., vertically. As a result, the first photocurable solution extends perpendicularly to the upper substrate 160 between the first color solution 147a and the second color solution 148a due to the density difference, and the second photocurable solution extends perpendicularly to the second And extends perpendicularly to the upper substrate 160 between the color solution 148a and the third color solution 149a.

The first and second photo-curable solutions are cured by irradiating light onto the upper substrate 160 arranged in parallel with the direction of the center of the earth to form first A first separation membrane 145a for separating the color solution 147a and the second color solution 148a from each other is formed and a second color solution 148a is formed between the second color solution 148a and the third color solution 149a, And the third color solution 149a are separated from each other.

8A to 8C are cross-sectional views illustrating a method of forming the display layer of FIG. 4 according to an embodiment of the present invention.

Referring to FIG. 8A, the display layer 140b 'includes display cells 142b' defined by barrier ribs 143b. FIG. 8A shows a section parallel to the center of the earth, and the downward direction in FIG. 8A corresponds to the direction of the center of the earth. The display layer 140b 'is for forming the display layer 140 of FIG. The display layer 140b 'may be formed on the common electrode 150 on the upper substrate 150. According to another example, the display layer 140b 'may be bonded between the common electrode 150 on the upper substrate 150 and the pixel electrodes 120 of the lower substrate 110 by the adhesive layer 130 .

Display cells 142b 'include a first color solution 147b' and a second color solution 148b '. Although not shown in FIG. 8A, the display cells 142b 'include electrophoretic particles 144 as shown in FIG. The first color solution 147b 'and the second color solution 148b' are substantially the same as the first color solution 147b and the second color solution 148b of FIG. 4, and include a photo-curable material.

The first and second color solutions 147b 'and 148b' including the photocurable material and the electrophoretic particles 144 are mixed to form an emulsion. The emulsion is injected into the space defined by the partition wall 143b. The cover layer 141b may be formed on the partition wall 143b so that the emulsion does not flow out to the outside.

The density of the first color solution 147b 'is smaller than that of the second color solution 148b'. As a result, as shown in Fig. 8A, when the display layer 140b 'is placed perpendicular to the direction of the center of the earth, the second color solution 148b' is positioned below and the first color solution 147b ' .

Referring to FIG. 8B, the display layer 140b 'is vertically erected. That is, the display layer 140b 'is disposed so as to extend in a direction parallel to the direction of the center of the earth. As a result, as shown in Fig. 8B, the first color solution 147b 'and the second color solution 148b' are laminated in the direction of the center of the earth. In this state, a mask for locally exposing the boundary portion 145b 'between the first color solution 147b' and the second color solution 148b 'is aligned. The mask is vertically erected similarly to the display layer 140b '. Light is locally irradiated to the display layer 140b 'vertically set using a mask. The light is irradiated only to the boundary portion 145b 'between the first color solution 147b' and the second color solution 148b 'of the vertically erected display layer 140b'. When the boundary portion 145b 'is irradiated with light, the boundary portion 145b' is cured so that the first separating film 145b separating the first coloring solution 147b and the second coloring solution 148b from each other .

Referring to FIG. 7C, the first separation layer 145b is formed to extend in a direction perpendicular to the extending direction of the display layer 140. The first separation membrane 145b is disposed in a direction parallel to the direction of the center of the earth, that is, vertically, and vertically separates the first color solution 147b and the second color solution 148b as shown in FIG. 8C . As a result, both the first color solution 147b and the second color solution 148b are seen in the direction of the common electrode 150. [

In the same manner, the display cell 142c of Fig. 5 can also be formed.

Referring to Fig. 5, a partition wall 143b is formed on the upper substrate 160, for example, on the common electrode 150 on the upper substrate 160. Fig. The emulsion containing the first to third color solutions 147c, 148c, and 149c, and the electrophoretic particles 144c is injected into the space defined by the partition wall 143b. The first to third color solutions 147c, 148c, and 149c include a photocurable material.

The first color solution 147a has a first density, the second color solution 148a has a second density that is greater than the first density, and the third color solution 149a has a third density that is greater than the second density . The electrophoretic particles 144a are dispersed in the first to third color solutions 147a, 148a and 149a.

The upper substrate 160 is arranged parallel to the direction of the earth's center, i.e., vertically. As a result, the first to third color solutions 147c, 148c, 149c are stacked in the direction of the center of the earth by the density difference, and the interfaces of the first to third color solutions 147c, 148c, And is perpendicular to the extending direction of the protrusion 160.

The upper substrate 160 arranged in parallel with the center of the earth is locally irradiated with light using a mask. The mask exposes the boundary portions of the first to third color solutions 147c, 148c, and 149c. Accordingly, the boundary portions of the first to third color solutions 147c, 148c and 149c are cured to form the first color solution 147c and the second color solution 147c between the first color solution 147c and the second color solution 148c The second color solution 148c and the third color solution 148c are formed between the second color solution 148c and the third color solution 149c, The second separation membrane 146c separating the first separation membrane 149c from the second separation membrane 146c is formed. As a result, the first to third color solutions 147c, 148c, and 149c are all seen in the direction of the common electrode 150. [

If each step constituting the manufacturing method according to the present invention is not explicitly described or contradicted, each step can be performed in an appropriate order. The present invention is not limited to the above-described embodiments. The use of all examples or exemplary terms (e.g., etc.) in the present invention is for the purpose of describing the present invention only in detail, and is not intended to limit the scope of the present invention by the use of the above examples or exemplary terms, The range is not limited. In addition, those skilled in the art will recognize that design criteria and factors can be modified within the scope of the claims or equivalents thereof.

Accordingly, the spirit of the present invention should not be limited to the above-described embodiments, and all ranges equivalent to or equivalent to the claims of the present invention as well as the claims of the following claims Category.

100: electrophoretic display device 110: lower substrate
120: pixel electrode 130: adhesive layer
140: display layer 150: common electrode
160: upper substrate 141: binder
142: microcapsule 143: capsule outer wall
144: electrophoretic particle 145: first separator
146: Second separation membrane 147: First color solution
148: Second color solution 149: Third color solution

Claims (1)

A first color solution having a first color and a first density, a second color solution having a second density different from the first density and greater than the first density, a second color solution having a second density different from the first density, An indicator layer comprising a first photocurable solution having a density less than a density and microcapsules each containing electrophoretic particles dispersed in the first color solution and electrophoretic particles firstly polarized in the second color solution, ;
Disposing the substrate parallel to the direction of the earth's center so that the first photocurable solution is perpendicular to the substrate between the first color solution and the second color solution by a density difference;
Irradiating light onto the substrate arranged parallel to the direction of the center of the earth to cure the first photocurable solution so as to cure the first color solution and the second color solution between the first color solution and the second color solution, Forming a first separating film for separating the first separating film and the second separating film from each other.

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