JP2009271317A - Electrophoresis display sheet, method for manufacturing electrophoresis display sheet, electrophoretic display device, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophoresis display sheet preventing reflection and having excellent visibility and enhanced texture (mat feeling similar to that of paper), to provide a method for manufacturing the electrophoresis display sheet, to provide an electrophoretic display device and to provide an electronic device. <P>SOLUTION: The electrophoretic display device 1 has: a microcapsule-containing layer 5 where a plurality of microcapsules 3 each containing electrophoresis dispersion liquid including two kinds of electrophoretic particles A and B in a shell body 31 are two-dimensionally (in a sheet shape) disposed; and an upper electrode (a first electrode) 6 provided on a viewing side of the microcapsule-containing layer 5 and a lower electrode (a second electrode) 7 provided on the opposite side. The upper electrode 6 has a plurality of convex parts (capsule upper convex parts 61) exposed to the outermost surface thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrophoretic display sheet, a method for producing an electrophoretic display sheet, an electrophoretic display device, and an electronic apparatus.

For example, an electrophoretic display using particle electrophoresis is known as an image display unit of electronic paper (see, for example, Patent Document 1). The electrophoretic display has excellent portability and power saving, and is particularly suitable as an image display unit of electronic paper.
Patent Document 1 describes a microcapsule type electrophoretic display panel having a front electrode plate and a back electrode plate arranged opposite to each other, and a capsule type electrophoretic layer provided therebetween. The capsule electrophoretic layer includes a large number of microcapsules filled with a dispersion liquid in which two kinds of particles having different polarities and different colors are dispersed. Such a microcapsule-type electrophoretic display panel is visually recognized through a front electrode plate by applying a voltage between the front electrode plate and the back electrode plate to cause particles in the microcapsule to migrate in a predetermined direction. The color to be changed is to be changed.

  However, in the microcapsule type electrophoretic display sheet described in Patent Document 1, the upper surface of the front electrode plate (the surface opposite to the capsule electrophoretic layer and exposed to the outside of the device) is a flat surface. As a result, the reflectance of the front electrode plate increases, and it reflects illumination and natural light, which appears to be reflected on the front electrode plate (so-called “reflection” occurs), which hinders visual recognition. End up.

JP 2008-58358 A

  An object of the present invention is to provide an electrophoretic display sheet, a method for producing an electrophoretic display sheet, an electrophoretic display device, and an electrophoretic display sheet, which prevent reflection and have excellent visibility and improved texture (matte feeling similar to paper) To provide electronic equipment.

Such an object is achieved by the present invention described below.
The electrophoretic display sheet of the present invention includes a microcapsule-containing layer in which a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell are arranged in a plane,
A first electrode provided on the viewing side of the microcapsule-containing layer and a second electrode provided on the opposite side;
The first electrode has a plurality of protrusions exposed on the outermost surface.
Accordingly, it is possible to provide an electrophoretic display sheet that prevents reflection and is excellent in visibility and improved in its texture (matte feeling similar to paper).

In the electrophoretic display sheet of the present invention, it is preferable that the plurality of convex portions include a capsule upper convex portion formed so as to cover the curved convex surface of the microcapsule.
As a result, the capsule upper convex portion can be formed uniformly (without coarseness) over the entire surface exposed to the outside of the first electrode (that is, the surface opposite to the microcapsule-containing layer). The reflection on the first electrode can be suppressed.

In the electrophoretic display sheet of the present invention, it is preferable that the microcapsule-containing layer has a wall portion that partitions the adjacent microcapsules.
Thereby, since several microcapsules can be made into a desired arrangement | positioning, while the display characteristic of an electrophoretic display sheet improves, the arrangement | positioning of a capsule convex part can be made into a desired thing.

In the electrophoretic display sheet according to the aspect of the invention, it is preferable that the plurality of convex portions include an upper convex portion that is formed so as to cover a top portion of the wall portion.
Thereby, the convex portion on the wall can be formed uniformly (roughly) on the surface exposed to the outside of the first electrode (that is, the surface opposite to the microcapsule-containing layer), Reflection on the first electrode can be suppressed. In particular, by combining with the capsule convex portion, that is, by forming two types of convex portions, the above effect becomes more remarkable.

In the electrophoretic display sheet of the present invention, it is preferable that the wall portion has a lattice shape in a plan view of the microcapsule-containing layer.
Thereby, the microcapsules can be arranged in a matrix (matrix), and the microcapsules can be arranged uniformly (without coarseness) in the microcapsule-containing layer, so that the display characteristics of the electrophoretic display sheet are improved. Further, since the capsule upper convex portion can also be formed in a matrix shape, reflection on the first electrode can be further suppressed.

In the electrophoretic display sheet of the present invention, it is preferable that the wall portion has a honeycomb shape in a plan view of the microcapsule-containing layer.
Thereby, since the microcapsules can be arranged more densely, the pixel density is increased and the display characteristics are further improved. In addition, since the capsule upper convex portion can be formed more densely, the reflection on the first electrode can be further suppressed.

In the electrophoretic display sheet of the present invention, it is preferable that the convex portion on the wall is arranged in the same planar shape as the wall in a plan view of the microcapsule-containing layer.
As a result, the upper convex portion of the wall can be formed uniformly (roughly) on the surface exposed to the outside of the first electrode (that is, the surface opposite to the microcapsule-containing layer). Can be further suppressed from being reflected on the electrode.
In the electrophoretic display sheet of the present invention, it is preferable that the minimum value of the radius of curvature of the convex portion on the wall is smaller than the minimum value of the radius of curvature of the convex portion on the capsule.
Thereby, the reflection to the 1st electrode can further be suppressed by the synergistic effect of a capsule upper convex part and a wall part upper convex part.

In the electrophoretic display sheet of the present invention, the height of the wall portion is preferably 0.5 to 1.25 times the length of the microcapsule-containing layer in the thickness direction of the microcapsule.
Thereby, the convex part on the wall can be easily formed while ensuring a large viewing angle of the electrophoretic display sheet.
In the electrophoretic display sheet of the present invention, the wall portion preferably has a thickness of 0.2 to 20 μm.
Thereby, while the separation distance of adjacent microcapsules can be shortened, the curvature of a convex part on a wall part can be enlarged comparatively easily.

In the electrophoretic display sheet of the present invention, it is preferable that the wall portion is white.
Thereby, the visibility of the electrophoretic display sheet is improved.
In the electrophoretic display sheet of the present invention, the first electrode is preferably formed by applying and drying a conductive polymer material on the viewing side of the microcapsule-containing layer.
Thereby, the first electrode can be formed relatively easily.

In the electrophoretic display sheet of the present invention, the polymer material is preferably composed of a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid.
Thereby, the 1st electrode excellent in visibility (light transmittance) and electroconductivity can be formed.
In the electrophoretic display sheet of the present invention, the polymer material is preferably one in which polyethylene dioxythiophene and polystyrene sulfonic acid are dispersed in an acrylate resin.
Thereby, the 1st electrode which is excellent in visibility (light transmittance) and electroconductivity, and has sufficient intensity can be formed.
In the electrophoretic display sheet of the present invention, the average thickness of the first electrode is preferably 2 to 60 μm.
Thereby, it is possible to form the first electrode excellent in visibility (light transmittance) while sufficiently securing the mechanical strength.

The method for producing an electrophoretic display sheet of the present invention is a method for producing an electrophoretic display sheet having a microcapsule-containing layer between a first electrode and a second electrode,
A first step of providing on the second electrode the microcapsule-containing layer in which a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell are arranged in a planar shape. When,
On the opposite side of the microcapsule-containing layer from the second electrode, a conductive resin material is applied and dried so as to cover the surface of the microcapsule, thereby having a plurality of protrusions exposed on the outermost surface. And a second step of forming a first electrode.
Thereby, it is possible to relatively easily manufacture an electrophoretic display sheet that prevents reflection and has excellent visibility and improved texture (matte feeling similar to paper).

The method for producing an electrophoretic display sheet of the present invention is a method for producing an electrophoretic display sheet having a microcapsule-containing layer between a first electrode and a second electrode,
On the second electrode, a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell and a wall portion partitioning the adjacent microcapsules are arranged in a plane. A first step of providing a microcapsule-containing layer,
By applying and drying a conductive resin material so as to cover the surface of the microcapsule and the top of the wall on the side opposite to the second electrode of the microcapsule-containing layer, a plurality of surfaces exposed on the outermost surface And a second step of forming the first electrode having a convex portion.
Thereby, it is possible to relatively easily manufacture an electrophoretic display sheet that prevents reflection and has excellent visibility and improved texture (matte feeling similar to paper).

The electrophoretic display device of the present invention includes the electrophoretic display sheet of the present invention and a substrate provided on the back surface side electrode side of the microcapsule-containing layer.
Accordingly, it is possible to provide an electrophoretic display device that prevents reflection and is excellent in visibility and improved in its texture (matte feeling similar to paper).
An electronic apparatus according to the present invention includes the electrophoretic display device according to the present invention.
Accordingly, it is possible to provide an electronic device including an electrophoretic display device that prevents reflection and is excellent in visibility and improved in texture (matte feeling similar to paper).

Hereinafter, an electrophoretic display sheet, an electrophoretic display sheet manufacturing method, an electrophoretic display device, and an electronic apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<Electrophoretic display device>
<< First Embodiment >>
First, a first embodiment of an electrophoretic display device (electrophoretic display device of the present invention) to which the electrophoretic display sheet of the present invention is applied will be described.

  FIG. 1 is a schematic plan view (top view) showing a first embodiment of an electrophoretic display device of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is shown in FIG. It is the elements on larger scale which show the upper electrode with which an electrophoretic display apparatus is provided, and a typical longitudinal cross-sectional view which shows the action | operation of the electrophoretic display apparatus shown in FIG. In the following, for convenience of explanation, the front side of the paper surface of FIG. 1 is referred to as “up”, the back side of the paper surface is referred to as “lower”, the upper side of FIG. Further, as shown in FIG. 1, three axes orthogonal to each other are defined as an x-axis, a y-axis, and a z-axis, respectively.

As shown in FIGS. 1 and 2, the electrophoretic display device 1 includes a circuit board (back plane) 9 and an electrophoretic display sheet 2 bonded to the upper surface of the circuit board 9.
As shown in FIG. 2, the electrophoretic display sheet 2 includes a plurality of (a plurality of) microcapsules 3 having a substantially spherical shape and a microcapsule-containing layer 5 having wall portions 4 separating them, and an upper surface of the microcapsule-containing layer 5 ( It has an upper electrode (first electrode) 6 provided on the display surface side and a lower electrode (second electrode) 7 provided on the lower surface side of the microcapsule-containing layer 5.
On the other hand, the circuit board 9 has a flat base 91 provided with a circuit (not shown) including a switching element such as a TFT.

Hereinafter, the structure of each part is demonstrated sequentially.
As shown in FIGS. 1 and 2, the wall 4 has a function of partitioning adjacent microcapsules 3. Such wall 4 may be either flexible or hard, but is preferably flexible. Use of the flexible wall 4 is advantageous in constructing a flexible electrophoretic display device 1, that is, for example, electronic paper.

  The wall 4 has a lattice shape in a plan view in FIG. 1 (a plan view when the electrophoretic display device 1 is viewed from above (display surface side); hereinafter, also simply referred to as “xy plan view”). Yes. Specifically, as shown in FIG. 1, the wall portion 4 includes a plurality of x-axis direction extending portions 41 extending in the x-axis direction, and extending in the y-axis direction and extending in the x-axis direction. And a plurality of extending portions 42 in the y-axis direction orthogonal (crossing). Each of the x-axis direction extending portion 41 and the y-axis direction extending portion 42 has a plate shape, and is provided so that its plate surface is parallel to the z-axis.

  Further, the plurality of x-axis direction extending portions 41 are arranged in parallel at the same pitch in the y-axis direction. Similarly, the plurality of y-axis direction extending portions 42 are also arranged in the x-axis direction at the same pitch. It is installed. In the present embodiment, the pitch p1 of the x-axis direction extending portion 41 and the pitch p2 of the y-axis extending portion 42 are set to be substantially the same. Therefore, a plurality of regions surrounded by the wall portion 4 (regions surrounded by a pair of adjacent x-axis direction extending portions 41 and a pair of adjacent y-axis direction extending portions 42) S1 are respectively xy planes. It is almost square in shape. In each of the plurality of regions S1, one microcapsule 3 is provided.

  In this way, the wall portion 4 is formed in a lattice shape, and one microcapsule 3 is provided in each of the plurality of regions S1 formed thereby, so that the microcapsule 3 is planar (sheet shape) and the matrix. Can be arranged in a matrix (matrix). Therefore, the microcapsules 3 can be arranged uniformly (without coarseness) in the microcapsule-containing layer 5.

  The pitches p1 and p2 are set to a value slightly larger than the outer diameter of the microcapsule 3, for example. Accordingly, one microcapsule 3 can be more reliably accommodated in each region S1 (that is, a plurality of microcapsules 3 can be prevented from being provided in one region S1), and the region S1. The movement (mutation) of the microcapsule 3 in the inside can be regulated. In addition, the distance between adjacent microcapsules 3 can be shortened, and the pixel density (number of microcapsules 3 per unit area (area in xy plan view)) can be increased. Therefore, the display characteristics of the electrophoretic display device 1 are improved.

  The x-axis direction extending portion 41 and the y-axis direction extending portion 42 have their thicknesses (the length in the y-axis direction in the x-axis direction extending portion 41 and the x-axis direction in the y-axis direction extending portion 42). Are the same). The thickness of the x-axis direction extending portion 41 (y-axis direction extending portion 42) is not particularly limited, but is preferably about 0.2 to 20 μm, and preferably about 1 to 5 μm. More preferred. Thereby, while ensuring the intensity | strength of the wall part 4 fully, and when the wall part 4 has flexibility, the separation distance of adjacent microcapsules 3 is ensured, also ensuring the softness | flexibility sufficiently. Can be shortened. That is, the pixel density can be increased and the display characteristics of the electrophoretic display device 1 can be improved while sufficiently securing the mechanical strength of the electrophoretic display device 1.

  The x-axis direction extending portion 41 and the y-axis direction extending portion 42 have the same height (length in the z-axis direction). The height of the x-axis direction extending portion 41 (y-axis direction extending portion 42) is not particularly limited, but is 0.5 to 1 of the outer diameter (length in the z-axis direction) of the microcapsule 3. It is preferably about 25 times, more preferably about 0.8 to 1.1 times. Thereby, the adjacent microcapsules 3 can be more reliably partitioned, and the collapse of the microcapsules 3 due to the contact between the microcapsules 3 can be prevented.

Further, for example, even when an external force in the vertical direction in FIG. 2 is applied to the microcapsule 3 due to, for example, finger pressure by the operator, the deformation of the microcapsule 3 due to the external force is suppressed to a small amount by the wall portion 4. Therefore, excessive deformation of the microcapsule 3 is prevented, and the collapse of the microcapsule 3 can also be prevented from this point.
Further, since excessive protrusion of the wall 4 upward in FIG. 2 is prevented, the viewing angle of the electrophoretic display device 1 can be secured sufficiently wide.

  The color of the wall portion 4 (the x-axis direction extension portion 41 and the y-axis direction extension portion 42) is not particularly limited, and is, for example, a dark color such as black, dark blue, or dark brown, white, yellow, pink And bright colors such as gold, silver and copper, and the like. Among these, light colors such as white, yellow and pink, particularly white are preferred. Since white is a color that reflects light without substantially absorbing light, the electrophoretic display device 1 can achieve brighter display and higher contrast by making the wall 4 white.

  As a constituent material of such a wall part 4 (x-axis direction extension part 41 and y-axis direction extension part 42), what has comparatively high insulation is used. Examples of such materials include various resin materials such as epoxy resins, acrylic resins, urethane resins, melamine resins, and phenol resins, and polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymers, Modified polyolefin, polyamide (eg nylon 6, nylon 66), styrene, polyvinyl chloride, polyurethane, polyester, fluororubber, chlorinated polyethylene and other thermoplastic elastomers, etc. A copolymer, a blend, a polymer alloy, etc. are mentioned, Among these, 1 type or 2 types or more can be mixed and used.

  In the present embodiment, nothing is provided in the space (lower portion of the region S1) formed by the wall portion 4, the microcapsule 3, and the lower electrode 7 (base portion 91) (that is, air is present). However, for example, a binder or the like may be provided. Thereby, for example, the microcapsule 3 can be fixed to the base 91 via the lower electrode 7. As the binder in this case, a resin material having excellent affinity (adhesion) with the microcapsule 3 and relatively high insulation is preferably used.

  Examples of such a binder include polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene, AS resin, ABS resin, methyl methacrylate, ethyl methacrylate, methacrylic acid. Methacrylic acid esters such as butyl and hydroxyethyl methacrylate, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride acrylate copolymer, vinyl chloride-methacrylic acid copolymer Polymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol-vinyl chloride copolymer, propylene-vinyl chloride copolymer, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl formal, cellulose resin, etc. Plastic resin, polyamide resin, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, polyamideimide, polyaminobismaleimide, polyethersulfone, polyphenylenesulfone, polyarylate, grafted polyphenylene ether, polyetheretherketone, Polymers such as polyetherimide, polytetrafluoroethylene, polyfluorinated ethylene propylene, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polytrifluoride Fluorine resins such as ethylene chloride and fluorine rubber, silicone resins such as silicone resin and silicone rubber, urethane resins such as polyurethane, As a methacrylic acid - styrene copolymer, polybutylene, methyl methacrylate - butadiene - various resin materials such as styrene copolymer may be mentioned may be used singly or in combination of two or more of them.

Next, the microcapsule 3 will be described. Since the plurality of microcapsules 3 have the same configuration, only one microcapsule 3 will be described as a representative, and the description of the other microcapsules 3 will be omitted. .
As shown in FIG. 2, the microcapsule 3 is provided in a region S <b> 1 surrounded by the wall 4. The microcapsule 3 has a substantially spherical shell 31 that defines an internal space 32, and an electrophoretic dispersion liquid containing two types of electrophoretic particles A and B is contained in the internal space 32. Filled (enclosed).

The shell 31 is substantially colorless and transparent so that the electrophoretic particles A and B existing inside (the internal space 32) can be visually recognized from the outside of the shell 31. By making the shell 31 colorless and transparent, the colors of the electrophoretic particles A and B are displayed more clearly (when the electrophoretic display device 1 is viewed from above (that is, the microcapsule is contained via the upper electrode 6). The color can be displayed when the layer 5 is viewed).
The average particle size of the microcapsule 3 is preferably about 10 to 200 μm, more preferably 20 to 60 μm, from the viewpoints of resolution, concealment rate, and the like.

Examples of the constituent material of the shell 31 include various resin materials such as gelatin, a composite material of gum arabic and gelatin, urethane resin, melamine resin, urea resin, polyamide, polyester, epoxy resin, and polyether. Of these, one or a combination of two or more can be used. Among these, the shell 31 is preferably made of melamine resin or urea resin as a main material. Thereby, since such a resin forms a three-dimensional network structure, the strength of the shell 31 can be improved, and for example, a spherical shape can be more reliably formed.
Moreover, you may make it form bridge | crosslinking (three-dimensional bridge | crosslinking) in the constituent material of the shell 31 with a crosslinking agent. Thereby, the strength of the shell 31 can be further improved.

  Such a microcapsule 3 preferably has a substantially uniform size (particle size). Specifically, the coefficient of variation (CV value) of the particle diameter is preferably 5 to 15%, and more preferably the coefficient of variation (CV value) is 5 to 10%. Thereby, in the electrophoretic display device 1, the occurrence of display unevenness can be prevented or reduced, and more excellent display performance can be exhibited.

The electrophoretic dispersion liquid includes a dispersion medium 8 and two types of electrophoretic particles A and B. The dispersion medium 8 is preferably substantially colorless and transparent. Further, as the dispersion medium 8, a medium having a relatively high insulating property is preferably used.
Examples of such a dispersion medium 8 include various types of water (distilled water, pure water, ion exchange water, etc.), alcohols such as methanol, ethanol, butanol, cellosolves such as methyl cellosolve, methyl acetate, ethyl acetate, and the like. Aromatics such as esters, ketones such as acetone and methyl ethyl ketone, aliphatic hydrocarbons such as pentane, alicyclic hydrocarbons such as cyclohexane, and benzenes having a long-chain alkyl group such as benzene and toluene Hydrocarbons, halogenated hydrocarbons such as methylene chloride and chloroform, aromatic heterocycles such as pyridine and pyrazine, nitriles such as acetonitrile and propionitrile, amides such as N, N-dimethylformamide, and carboxylic acids Mineral oils such as salt and liquid paraffin, vegetable oils such as linoleic acid, linolenic acid and oleic acid, dimethyl Examples include silicone oils such as corn oil, methylphenyl silicone oil, and methylhydrogen silicone oil, fluorine-based liquids such as hydrofluoroether, and other various oils, and other various oils. Can be used alone or as a mixture.
In addition, in the dispersion medium 8, for example, a charge control agent composed of particles of electrolyte, surfactant, metal soap, resin material, rubber material, oils, varnish, compound, etc., titanium-based coupling, if necessary. You may make it add various additives, such as dispersing agents, lubricants, stabilizers, such as an agent, an aluminum coupling agent, and a silane coupling agent.

The electrophoretic particles A and the electrophoretic particles B have different colors. The color (color) of the electrophoretic particle A and the electrophoretic particle B is not particularly limited, and two colors are arbitrarily selected from achromatic colors such as white, black, and gray, and chromatic colors such as red, blue, and green. Can be selected. In this embodiment, for convenience of explanation, the electrophoretic particles A are white and the electrophoretic particles B are black. Thereby, as will be described later, monochrome display is possible, and the display characteristics, particularly the visibility, of the electrophoretic display device 1 are improved.
In addition, the electrophoretic particles A and the electrophoretic particles B are particles charged to opposite polarities. In the following, for convenience of explanation, the case where the electrophoretic particle A is negatively charged and the electrophoretic particle B is positively charged will be described as a representative. Note that this may be reversed.

  As such electrophoretic particles A and B, any particles can be used as long as they satisfy the above-mentioned conditions, and are not particularly limited. However, pigment particles, resin particles, ceramic particles, At least one of metal particles, metal oxide particles, or composite particles thereof is preferably used. These particles have the advantage that they are easy to manufacture and the charge can be controlled relatively easily.

  Examples of pigments constituting the pigment particles include black pigments such as aniline black, carbon black, and titanium black, white pigments such as titanium dioxide, antimony trioxide, zinc sulfide, and zinc white, and azo series such as monoazo, disazo, and polyazo. Pigments, yellow pigments such as isoindolinone, yellow lead, yellow iron oxide, cadmium red and titanium red, azo pigments such as monoazo, disazo and polyazo, red pigments such as quinacridone red and chrome vermillion, phthalocyanine blue and indanthrene Blue pigments such as blue, bitumen, ultramarine, and cobalt blue, green pigments such as phthalocyanine green, and the like can be used, and one or more of these can be used in combination.

Examples of the resin material constituting the resin particles include acrylic resin, urethane resin, urea resin, epoxy resin, rosin resin, polystyrene, polyester, AS resin copolymerized with styrene and acrylonitrile, and the like. These can be used alone or in combination of two or more.
The composite particles are, for example, composed of pigment particles whose surfaces are coated with a resin material, resin particles whose surfaces are coated with a pigment, or a mixture of a pigment and a resin material mixed in an appropriate composition ratio. Particles and the like.

  The average particle diameter of the electrophoretic particles A and B is not particularly limited, but is preferably about 0.05 to 10 μm, and more preferably about 0.1 to 3.0 μm. If the average particle diameter of the particles is too small, a sufficient concealment rate cannot be obtained mainly in the visible light range, and as a result, the display contrast of the electrophoretic display device 1 may be lowered. If the particle size is too large, depending on the type or the like, the liquid phase dispersion medium tends to settle, which may cause problems such as deterioration in display quality of the electrophoretic display device 1.

The electrophoretic particles A and B have been described above. The dispersion of the two types of electrophoretic particles A and B in the dispersion medium 8 can be performed by, for example, the paint shaker method, the ball mill method, the media mill method, or the ultrasonic dispersion. The method can be carried out by combining one or more of the methods, stirring and dispersing methods and the like.
The microcapsule-containing layer 5 has been described in detail above.

Next, the upper electrode 6 and the lower electrode 7 for applying (acting) an electric field to the microcapsule-containing layer 5 will be described.
As shown in FIG. 2, the upper electrode 6 is provided on the upper side (display surface side) of the microcapsule-containing layer 5. Such an upper electrode 6 is substantially colorless and transparent. Thereby, it is possible to display the colors of the electrophoretic particles A and B as display colors more clearly.
The upper electrode 6 is provided so as to cover the top 4a of the wall 4 and the surface of the microcapsule 3 (curved convex surface located on the upper side in FIG. 1). The upper surface 6a of such an upper electrode 6 constitutes the outermost surface of the electrophoretic display device 1 (electrophoretic display sheet 2). That is, the upper surface 6 a of the upper electrode 6 is exposed to the outside of the electrophoretic display device 1.

  As shown in FIG. 2, the upper electrode 6 has two types of convex portions exposed on the outermost surface of the electrophoretic display device 1, that is, a capsule upper convex portion 61 and a wall upper convex portion 62. Each of the capsule upward convex portion 61 and the wall upward convex portion 62 protrudes upward in FIG. By providing such convex portions 61 and 62, the regular reflection light from the upper electrode 6 can be made sufficiently low, and most of the light and natural light from the illumination installed outside the electrophoretic display device 1 is obtained. The microcapsule-containing layer 5 is not reflected by the upper electrode 6. Therefore, the so-called “reflection” in which the light source such as the illumination moves to the upper electrode 6 can be prevented, and the visibility of the electrophoretic display device 1 is improved. In addition, since the amount of light reaching the microcapsule-containing layer 5 increases, a bright display with a high display contrast is possible. From this point, the visibility of the electrophoretic display device 1 is improved.

A large number (a plurality) of capsule upper convex portions 61 are formed corresponding to the microcapsules 3. Specifically, one capsule upper convex portion 61 is provided above (directly above) each microcapsule 3 so as to cover the curved convex surface of the microcapsule 3.
Each of the capsule upper convex portions 61 has a curved convex surface having a substantially spherical shape. Thereby, in the upper electrode 6, reflection is suppressed regardless of the angle at which the display surface of the electrophoretic display device 1 is viewed.

In the present embodiment, since a large number of microcapsules 3 are arranged in a matrix (matrix), a large number of capsule convex portions 61 are also arranged in a matrix correspondingly. For this reason, the capsule upper convex portion 61 is uniformly (roughly) arranged on the upper surface 6a of the upper electrode 6, and the reflectance of the upper electrode 6 is uniformly reduced over the entire area.
The radius of curvature of the capsule convex portion 61 is substantially the same as or slightly larger than the curvature of the surface of the microcapsule 3 located immediately below the convex portion 61. The curvature radius of the capsule convex portion 61 varies depending on the size (outer diameter) of the microcapsule 3 and the like, but is preferably about 5 to 120 μm, for example, about 10 to 40 μm. More preferred.

  Further, the height of the capsule upper protrusion 61 is not particularly limited, but is preferably about 2 to 50 μm, and more preferably about 5 to 10 μm. Thereby, the regular reflection light reflectance of the upper electrode 6 can be sufficiently lowered, and the reflection can be more reliably prevented, so that the visibility of the electrophoretic display device 1 is improved. In addition, since the upper surface (exposed surface) 6a of the upper electrode 6 can be made to have a rough and less glossy texture like paper (matte feeling similar to paper), it is particularly advantageous when constructing electronic paper. It becomes.

  On the other hand, the wall upper protrusion 62 is formed so as to cover the top 4a of the wall 4 as shown in FIG. In the present embodiment, since the wall 4 is formed in a lattice shape, the wall upper convex portion 62 has a lattice shape corresponding thereto. That is, as shown in FIG. 1, the wall upper protrusions 62 are arranged in the same planar shape as the wall 4 in the xy plan view. For this reason, the wall upper protrusions 62 are uniformly (roughly) arranged on the upper surface 6a of the upper electrode 6, and the regular reflection light reflectance of the upper electrode 6 is uniformly reduced.

Specifically, referring to FIG. 1, the wall upper protrusion 62 includes a plurality of x-axis direction extending ridges 621 extending in the x-axis direction and the y-axis direction extending in the x-axis direction. It has a plurality of protruding ridges 622 extending in the y-axis direction perpendicular to (intersecting with) the extending ridges 621.
The plurality of x-axis direction extending ridges 621 are each formed to cover the top 4 a of the x-axis direction extending portion 41 of the wall portion 4. The plurality of y-axis direction extending ridges 622 are formed so as to cover the top 4 a of the y-axis direction extending portion 42. Therefore, as shown in FIG. 3, a plurality of regions (a pair of adjacent x-axis direction extending ridges 621 and a pair of adjacent y-axis direction extending ridges 622 surrounded by the upper convex part 62 of the wall portion. The enclosed area (S2) has a substantially square shape corresponding to the area S1 in the xy plan view.

  As shown in FIG. 3, one capsule upper convex portion 61 is provided in each of the plurality of regions S <b> 2. From this, the upper surface 6a of the upper electrode 6 has an annular convex portion (wall convex portion 62) whose outer shape and inner shape are both substantially square in an xy plan view, and a curve provided on the inside thereof. It can also be said that a concavo-convex pattern is formed in which a large number of concavo-convex portions constituted by convex portions forming the convex surface (capsule upper convex portion 61) are arranged in a matrix (matrix shape).

Hereinafter, the x-axis direction extending ridges 621 and the y-axis direction extending ridges 622 will be described in detail, respectively. However, the x-axis direction extending ridges 621 and the y-axis direction extending ridges 622 are extended. Since the configuration is the same except that the direction of movement is different, the x-axis direction extending ridge 621 will be described as a representative, and the y-axis direction extending ridge 622 will not be described.
FIG. 2 shows a cross section of the protruding ridge 621 extending in the x-axis direction. As shown in the figure, the x-axis direction extending ridge 621 is rounded. Moreover, the curvature becomes large as it approaches the front-end | tip part 621a. It is preferable that the minimum value of the radius of curvature of the projecting ridge 621 extending in the x-axis direction (the radius of curvature at the tip 621a) is smaller than the radius of curvature of the capsule upper convex portion 61. Thereby, the reflection on the upper electrode 6 can be more reliably prevented by the synergistic effect of the capsule upper convex portion 61 and the wall upper convex portion 62.
The minimum value of the radius of curvature of the ridges 621 extending in the x-axis direction is not particularly limited, but is preferably about 2 to 30 μm, and more preferably about 2 to 10 μm.

  The height of the x-axis direction extending ridge 621 (the length in the z-axis direction) depends on the height of the x-axis direction extending portion 41 of the wall portion 4. For example, in FIG. 2, if the apex 4 a of the x-axis direction extending portion 41 is located above the uppermost portion (point Q) of the microcapsule 3, the x-axis direction extending ridge 621. Is higher than the capsule upper convex portion 61, and conversely, if the apex 4a is located below the point Q, the x-axis direction extending ridge 621 becomes lower than the capsule upper convex portion 61, If the top 4 a is located at the same height as the point Q, the x-axis direction extending ridge 621 becomes the same height as the capsule upper protrusion 61.

  The height of the convex part 62 on the wall part may be higher, lower, or the same as the convex part 61 on the capsule. For example, it is preferably about 2 to 50 μm, and preferably about 5 to 10 μm. It is more preferable that Thereby, the reflectance of the upper electrode 6 can be sufficiently lowered, and reflection on the upper electrode 6 can be more reliably prevented. Therefore, the visibility of the electrophoretic display device 1 is improved. In addition, the upper surface 6a of the upper electrode 6 can be made to have a rough and less glossy texture like paper (a matte feeling similar to paper), which is particularly advantageous when constructing electronic paper.

The upper electrode 6 has been described in detail above. The average thickness of the upper electrode 6 is preferably about 2 to 60 μm, and more preferably about 5 to 15 μm. Thereby, the upper electrode 6 excellent in visibility can be formed while sufficiently securing the mechanical strength. Specifically, the upper electrode 6 is substantially colorless and transparent, but has some light absorption and scattering properties, so that the average thickness of the upper electrode 6 is in the above range. As a result, attenuation of display contrast is suppressed, and the upper electrode 6 having excellent visibility can be obtained.
The upper electrode 6 is preferably formed by applying a polymer material having conductivity so as to cover the microcapsule 3 and the top 4a of the wall 4 and drying. Thereby, the average thickness of the upper electrode 6 can be made relatively thin as in the above-described range relatively easily.

  Examples of conductive polymer materials include polypyrrole, polythiophene, polyfuran, polyaniline, polyparaphenylene, polyparaphenylene vinylene, polyfluorene, polystyrene, polyacetylene, derivatives thereof, and monomers constituting them. Examples thereof include any one kind or a mixture of two or more kinds of polymers selected from those. Among these, it is more preferable to use a material containing polydioxythiophene, particularly a mixture of polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS). Since this mixture can be dissolved or diffused in water or other solvents (for example, alcohol such as ethanol) and can be easily coated into a film, it can be suitably used as a constituent material of the upper electrode 6. Further, since both transparency and conductivity are high, it can be suitably used as a constituent material of the upper electrode 6 in this respect.

  Furthermore, the strength of the upper electrode 6 can be increased with a material in which a mixture of PEDOT and PSS (hereinafter also simply referred to as “PEDOT / PSS”) is dispersed in an acrylate resin. The strength of the upper electrode 6 can also be increased by a material in which PEDOT / PSS is dispersed in a mixture of a vinyl ester resin and an acrylate resin. At this time, the content of PEDOT / PSS is preferably about 15 to 25 parts by weight with respect to 100 parts by weight of the mixture of the vinyl ester resin and the acrylate resin.

  On the other hand, as shown in FIG. 2, a large number of lower electrodes 7 are arranged in a matrix on the lower surface of the microcapsule-containing layer 5 so as to correspond to the microcapsules 3. That is, one lower electrode 7 is provided immediately below one microcapsule 3. In such an electrophoretic display device 1, a portion where the upper electrode 6 and one lower electrode 7 overlap constitutes one pixel.

Each lower electrode 7 has a plate shape and is located inside the region S1 surrounded by the wall 4 in the xy plan view. Moreover, the planar view shape of each lower electrode 7 is substantially square. The shape of the lower electrode 7 is not particularly limited. For example, the planar view shape may be a circle or a polygon other than a square.
Each such lower electrode 7 may be opaque or transparent.

In addition, the constituent material of the lower electrode 7 is not particularly limited as long as it is substantially conductive. For example, a metal material such as copper, aluminum or an alloy containing these, a carbon-based material such as carbon black, An ionic substance such as NaCl, LiClO ₄ , KCl, LiBr, LiNO ₃ , LiSCN or the like in an electroconductive polymer material such as polyacetylene, polypyrrole, or a derivative thereof, or a matrix resin such as polyvinyl alcohol, polycarbonate, or polyethylene oxide. Of conductive oxide materials such as dispersed ion conductive polymer materials, indium tin oxide (ITO), fluorine doped tin oxide (FTO), tin oxide (SnO ₂ ), indium oxide (IO), etc. Various conductive materials such as these are listed, and one or more of these are combined. So it can be used.
Heretofore, the configuration of each part of the electrophoretic display device 1 has been described.

-Operation of the electrophoretic display device 1-
Such an electrophoretic display device 1 operates as follows.
FIG. 4 is a schematic diagram for explaining an operation method of the electrophoretic display device shown in FIG. In the following description, the upper side in FIG. 4 is referred to as “upper” and the lower side is referred to as “lower”.
When a voltage is applied between the upper electrode 6 and the lower electrode 7 of the electrophoretic display device 1 by a power source (not shown), an electric field is generated between them. That is, an electric field is generated in the microcapsule-containing layer 5. In accordance with the electric field generated in the microcapsule-containing layer 5, the electrophoretic particles A and B move (electrophoresis) toward one of the electrodes (upper electrode 6 and lower electrode 7).

  For example, when a voltage is applied between the upper electrode 6 and the lower electrode 7 so that the upper electrode 6 has a positive potential and the lower electrode 7 has a negative potential, the negatively charged white electrophoretic particles A are applied to the upper electrode 6. The positively charged black electrophoretic particles B that move toward the lower electrode 7 move toward the lower electrode 7. As a result, as shown in FIG. 4A, the electrophoretic particles A gather at the upper electrode 6 and the electrophoretic particles B gather at the lower electrode 7. For this reason, when the electrophoretic display device 1 is viewed from above (that is, when the capsule-containing layer 5 is viewed through the upper electrode 6), the color of the electrophoretic particles A, that is, white can be seen.

On the contrary, when a voltage is applied between the upper electrode 6 and the lower electrode 7 so that the upper electrode 6 has a negative potential and the lower electrode 7 has a positive potential, the electrophoretic particles A are directed toward the lower electrode 7. The electrophoretic particles B move and move toward the upper electrode 6. As a result, as shown in FIG. 4B, the electrophoretic particles A gather at the lower electrode 7 and the electrophoretic particles B gather at the upper electrode 7. For this reason, when the electrophoretic display device 1 is viewed from above, the color of the electrophoretic particles B, that is, black, is visible.
In such a configuration, the electrophoretic display device 1 is set by appropriately setting the charge amount of the electrophoretic particles A and B, the polarity of the upper electrode 6 or the lower electrode 7, the potential difference between the upper electrode 6 and the lower electrode 7, and the like. The desired information (image) is displayed in accordance with the combination of the colors of the electrophoretic particles A and the electrophoretic particles B, the number of particles gathered on the upper electrode 6, and the like.

-Manufacturing method of electrophoretic display device-
Next, a manufacturing method of the electrophoretic display device 1 (a manufacturing method of the present invention) will be described in detail with reference to the drawings. 5 and 6 are schematic views for explaining a method of manufacturing the electrophoretic display device shown in FIG. In the following description, the upper side in FIGS. 5 and 6 is referred to as “upper” and the lower side is referred to as “lower”.

<1> Production Process of Microcapsule 3 First, the microcapsule 3 encapsulating the electrophoretic dispersion liquid having the dispersion medium 8 and the electrophoretic particles A and B is produced. The method for producing the microcapsule 3 (method for encapsulating the electrophoretic dispersion in the shell 31) is not particularly limited. For example, an interfacial polymerization method, an in-situ polymerization method, a phase separation method (or a coacervation method). Various microencapsulation methods such as an interfacial sedimentation method and a spray drying method can be used. Note that the microencapsulation method may be appropriately selected according to the constituent material of the microcapsule 3 and the like. The microcapsules 3 having a uniform size can be obtained by using, for example, a method of screening through a sieve, a filtration method, a specific gravity differential class method, or the like.
The average particle size of the microcapsules 3 is preferably about 10 to 200 μm, and more preferably 20 to 60 μm. By setting the average particle diameter of the microcapsules 3 in the above range, the electrophoresis of the electrophoretic particles A and B can be more reliably controlled in the manufactured electrophoretic display device 1.

<2> Preparation Step of Microcapsule Dispersion Next, the microcapsule 3 produced as described above and a solvent are mixed to prepare a microcapsule dispersion. Although it does not specifically limit as said solvent, For example, the water-ethanol liquid mixture whose mixing ratio is 1: 1 can be used. The content of the microcapsule 3 in the microcapsule dispersion is preferably about 10 to 80 wt%, and more preferably about 30 to 60 wt%.

<3> Step of Forming Microcapsule-Containing Layer First, as shown in FIG. 5A, a base 91 (circuit board 9) on which switching elements such as TFTs (not shown) are formed is prepared, and a large number of them are formed on the upper surface. Lower electrodes 7 are arranged in a matrix.
Next, as shown in FIG. 5B, the separately prepared wall 4 is bonded to the circuit board 9 using, for example, an adhesive. At this time, it is preferable that the wall 4 and the lower electrode 7 do not overlap. That is, it is preferable that the entire lower electrode 7 is located in each region S1.

  In addition, the wall part 4 prepares the plate-shaped (sheet-shaped) member comprised with the material as mentioned above, for example, The said plate-shaped member has many through-holes penetrated in the thickness direction in a matrix form. Prepared by forming. A method for forming the through hole is not particularly limited. For example, one of a physical etching method such as plasma etching, reactive ion etching, beam etching, and optically assisted etching, and a chemical etching method such as wet etching is used. Alternatively, two or more kinds can be used in combination.

Next, as shown in FIG. 5C, the microcapsule dispersion obtained in <2> is supplied (dropped) on the wall 4, and one microcapsule 3 is arranged in each region S <b> 1. At this time, for example, as shown in FIG. 5 (d), the squeegee (flat jig) 100 is passed over the wall 4 and the microcapsule 3 is directed downward as necessary. May be. Thereby, the one microcapsule 3 can be arrange | positioned more reliably in each area | region S1.
Next, by removing the solvent by drying (natural drying, forced drying) or the like, a microcapsule-containing layer 5 in which one microcapsule 3 is provided in each region S1 as shown in FIG. 5E is obtained. .

<4> Step of forming upper electrode First, a polymer material having conductivity as described above, for example, a mixture of polyethylenedioxythiophene (PEDOT) and polystyrenesulfonic acid (PSS) is prepared. Although it does not specifically limit as a viscosity of such a polymeric material, For example, it is preferable that it is about 10 < ² > -10 < ⁴ > (P), and it is more preferable that it is about 10 < ² > -10 < ³ > (P). By setting the viscosity of the polymer material within the above range, it is possible to relatively easily form a convex portion having a shape corresponding to the shape of the top portion 4 a of the wall portion 4 and the curved convex surface of the microcapsule 3. In addition, excessive downward dripping (flow) due to its own weight can be suppressed, and for example, contact with the lower electrode 6 can be prevented.

  Next, the prepared polymer material is applied to the upper surface side of the microcapsule-containing layer 5, that is, so as to cover the curved convex surface of the microcapsule 3 and the top portion 4a of the wall portion 4, and is dried. As a result, as shown in FIG. 6, the upper electrode 6 having the capsule upper protrusion 61 and the wall upper protrusion 62 exposed on the outermost surface is formed. In addition, it does not specifically limit as a method of apply | coating a polymeric material to the upper surface of the microcapsule content layer 5, For example, various application methods, such as a screen printing method, a dispenser method, a spray coat method, can be used, for example.

Through the above steps, the electrophoretic display device 1 is obtained.
In the case where the binder as described above is provided in the space formed by the wall portion 4, the microcapsule 3, and the lower electrode 6, the base portion 91 (circuit circuit) is provided prior to the step of bonding the wall portion 4 to the circuit board 9. What is necessary is just to apply | coat a binder to the upper surface (surface in which the lower electrode 7 is provided) of the board | substrate 9).

  According to the manufacturing method as described above, the electrophoretic display device 1 provided with the upper electrode 6 having the capsule upper protrusion 61 and the wall upper protrusion 62 can be manufactured relatively easily. Further, as shown from the above-described steps, according to such a manufacturing method, it is not necessary to apply pressure when forming the upper electrode 6, so that the shape of the microcapsule 3 can be easily maintained in a substantially spherical shape. The upper convex part 61 can be formed more reliably. In addition, bleeding out of the electrophoretic dispersion from the microcapsule 3 can be prevented.

<< Second Embodiment >>
Next, a second embodiment of the electrophoretic display device of the present invention will be described.
FIG. 7 is a plan view showing a second embodiment of the electrophoretic display device of the present invention, and FIG. 8 is a partially enlarged perspective view showing an upper electrode provided in the electrophoretic display device shown in FIG.
Hereinafter, the electrophoretic display device according to the second embodiment will be described with a focus on differences from the above-described embodiments, and description of similar matters will be omitted.
The electrophoretic display device according to the second embodiment of the present invention is the same as the electrophoretic display device according to the first embodiment except that the shape (planar shape) of the wall portion and the upper convex portion of the wall portion of the microcapsule-containing layer is different. It is the same. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.

  FIG. 7 is a plan view (top view) of the electrophoretic display device 1, but the illustration of the upper electrode 6 is omitted for convenience of explanation. As shown in the figure, the wall 4 has a honeycomb shape in the xy plan view. In each of a large number of regions S3 surrounded by the wall portion 4, one microcapsule 3 is provided. As described above, the wall portion 4 is formed in a honeycomb shape, and one microcapsule 3 is provided in each of a large number of regions S3 formed thereby, so that a large number of microcapsules 3 can be arranged more densely. Therefore, the pixel density is higher than that of the electrophoretic display device 1 of the first embodiment, for example, and the display characteristics of the electrophoretic display device 1 are improved.

The upper convex portion 62 of the wall portion of the upper electrode 6 is formed so as to cover the top portion of the wall portion 4 and is arranged in the same honeycomb shape as the wall portion 4 in the xy plan view as shown in FIG. ing. A capsule upper convex portion 61 is provided in the region S4 surrounded by the wall upper convex portion 62 as described above. For this reason, the upper surface 6a of the upper electrode 6 is provided with an annular convex portion (wall portion convex portion 62) whose outer shape and inner shape are both substantially regular hexagons in the xy plan view, and the inner side thereof. It can be said that a concavo-convex pattern formed by regularly arranging a large number of concavo-convex portions formed by convex portions (capsule convex portions 61) forming a curved convex surface is formed.
Also by such 2nd Embodiment, the effect similar to 1st Embodiment can be exhibited.

The electrophoretic display device 1 as described above can be incorporated into various electronic devices. As an electronic apparatus of the present invention provided with an electrophoretic display device, for example, an electronic paper, an electronic book, a television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, an electronic newspaper, Examples include a word processor, a personal computer, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel.
Of these electronic devices, an electronic paper will be described as an example for specific description.

FIG. 9 is a perspective view showing an embodiment when the electronic apparatus of the present invention is applied to electronic paper.
An electronic paper 600 shown in FIG. 9 includes a main body 601 composed of a rewritable sheet having the same texture and flexibility as paper, and a display unit 602.
In such an electronic paper 600, the display unit 602 includes the electrophoretic display device 1 as described above.

Next, an embodiment when the electronic apparatus of the present invention is applied to a display will be described.
FIG. 10 is a diagram showing an embodiment when the electronic apparatus of the present invention is applied to a display. Among these, (a) in FIG. 10 is a sectional view and (b) is a plan view.
A display (display device) 800 shown in FIG. 10 includes a main body portion 801 and an electronic paper 600 that is detachably attached to the main body portion 801. The electronic paper 600 has the same configuration as described above, that is, the configuration shown in FIG.

  The main body 801 has an insertion port 805 into which the electronic paper 600 can be inserted on the side (right side in FIG. 10), and two pairs of conveying rollers 802a and 802b are provided inside. When the electronic paper 600 is inserted into the main body 801 through the insertion port 805, the electronic paper 600 is installed in the main body 801 in a state of being sandwiched between the pair of conveyance rollers 802a and 802b.

  A rectangular hole 803 is formed on the display surface side of the main body 801 (the front side in FIG. 10B), and a transparent glass plate 804 is fitted into the hole 803. . Thereby, the electronic paper 600 installed in the main body 801 can be viewed from the outside of the main body 801. That is, in the display 800, the display surface is configured by visually recognizing the electronic paper 600 installed in the main body 801 on the transparent glass plate 804.

Further, a terminal portion 806 is provided at the leading end portion (left side in FIG. 10) of the electronic paper 600 in the insertion direction, and the terminal is provided inside the main body portion 801 with the electronic paper 600 installed on the main body portion 801. A socket 807 to which the unit 806 is connected is provided. A controller 808 and an operation unit 809 are electrically connected to the socket 807.
In such a display 800, the electronic paper 600 is detachably installed on the main body 801, and can be carried and used while being detached from the main body 801.

  The electrophoretic display sheet, the electrophoretic display sheet manufacturing method, the electrophoretic display device, and the electronic apparatus according to the invention have been described above based on the illustrated embodiments. However, the invention is not limited thereto. . For example, in the electrophoretic display sheet, the electrophoretic display device, and the electronic apparatus of the present invention, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, and an arbitrary configuration is added. You can also

In the above-described embodiment, the case where one microcapsule is provided immediately above one lower electrode has been described. However, the present invention is not limited to this. For example, two or more plural ones are provided immediately above one lower electrode. Microcapsules may be located.
In the embodiment described above, the microcapsule-containing layer has been described as having a wall, but the present invention is not limited to this, and the wall may be omitted. In this case, the convex portion on the wall is also omitted.

1 is a schematic plan view (top view) showing a first embodiment of an electrophoretic display device of the present invention. It is the sectional view on the AA line in FIG. It is the elements on larger scale which show the upper electrode with which the electrophoretic display apparatus shown in FIG. 1 is provided. It is a typical longitudinal cross-sectional view which shows the action | operation of the electrophoretic display apparatus shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the electrophoretic display device shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the electrophoretic display device shown in FIG. FIG. 7 is a plan view showing a second embodiment of the electrophoretic display device of the present invention. FIG. 8 is a partially enlarged perspective view showing an upper electrode provided in the electrophoretic display device shown in FIG. 7. It is a perspective view which shows embodiment at the time of applying the electronic device of this invention to electronic paper. It is a figure which shows embodiment at the time of applying the electronic device of this invention to a display.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electrophoretic display device 2 ... Electrophoretic display sheet 3 ... Microcapsule 31 ... Shell (shell) 32 ... Internal space 4 ... Wall part 4a ... Top part 41 ... Extension part in x-axis direction 42 …… y-axis extending portion 5 …… microcapsule containing layer 6 …… upper electrode (first electrode) 6a …… upper surface 61 …… upper capsule convex portion 62 …… upper convex portion 621 …… x Axis extending ridges 621a …… Tip 622 …… Y axis extending ridges 7 …… Lower electrode (second electrode) 8 …… Dispersion medium 9 …… Circuit substrate 91 …… Base 100… Squeegee 600 ... Electronic paper 601 ... Main body 602 ... Display unit 800 ... Display 801 ... Main body 802a, 802b ... Conveying roller pair 803 ... Hole 804 ... Transparent glass plate 805 ... Insertion slot 806 ... Terminal portion 807 ...... socket 808 ...... controller 809 ...... operating unit A, B ...... electrophoretic particles S1 to S4 ...... region

Claims (19)

A microcapsule-containing layer in which a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell are arranged in a plane;
A first electrode provided on the viewing side of the microcapsule-containing layer and a second electrode provided on the opposite side;
The electrophoretic display sheet, wherein the first electrode has a plurality of protrusions exposed on the outermost surface.   The electrophoretic display sheet according to claim 1, wherein the plurality of convex portions include a capsule upper convex portion formed so as to cover the curved convex surface of the microcapsule.   The electrophoretic display sheet according to claim 1, wherein the microcapsule-containing layer has a wall portion that partitions adjacent microcapsules.   The electrophoretic display sheet according to claim 3, wherein the plurality of convex portions include a wall upper convex portion formed so as to cover a top portion of the wall portion.   The electrophoretic display sheet according to claim 4, wherein the wall portion has a lattice shape in a plan view of the microcapsule-containing layer.   The electrophoretic display sheet according to claim 4, wherein the wall portion has a honeycomb shape in a plan view of the microcapsule-containing layer.   The electrophoretic display sheet according to claim 5, wherein the convex portion on the wall is arranged in a planar shape similar to the wall in a plan view of the microcapsule-containing layer.   8. The electrophoretic display sheet according to claim 4, wherein a minimum value of a curvature radius of the convex portion on the wall is smaller than a minimum value of a curvature radius of the convex portion on the capsule.   The electrophoretic display sheet according to claim 3, wherein the height of the wall is 0.5 to 1.25 times the length of the microcapsule-containing layer in the thickness direction. .   The electrophoretic display sheet according to claim 3, wherein the wall portion has a thickness of 0.2 to 20 μm.   The electrophoretic display sheet according to claim 3, wherein the wall portion is white.   12. The electrophoresis according to claim 1, wherein the first electrode is formed by applying and drying a conductive polymer material on the viewing side of the microcapsule-containing layer. Display sheet.   The electrophoretic display sheet according to claim 1, wherein the polymer material is made of a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid.   The electrophoretic display sheet according to claim 1, wherein the polymer material is obtained by dispersing polyethylene dioxythiophene and polystyrene sulfonic acid in an acrylate resin.   The electrophoretic display sheet according to claim 1, wherein an average thickness of the first electrode is 2 to 60 μm. A method for producing an electrophoretic display sheet having a microcapsule-containing layer between a first electrode and a second electrode,
A first step of providing on the second electrode the microcapsule-containing layer in which a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell are arranged in a planar shape. When,
On the opposite side of the microcapsule-containing layer from the second electrode, a conductive resin material is applied and dried so as to cover the surface of the microcapsule, thereby having a plurality of protrusions exposed on the outermost surface. A method for producing an electrophoretic display sheet, comprising: a second step of forming a first electrode. A method for producing an electrophoretic display sheet having a microcapsule-containing layer between a first electrode and a second electrode,
On the second electrode, a plurality of microcapsules enclosing an electrophoretic dispersion liquid containing at least one kind of electrophoretic particles in a shell and a wall portion partitioning the adjacent microcapsules are arranged in a plane. A first step of providing a microcapsule-containing layer,
By applying and drying a conductive resin material so as to cover the surface of the microcapsule and the top of the wall on the side opposite to the second electrode of the microcapsule-containing layer, a plurality of surfaces exposed on the outermost surface And a second step of forming the first electrode having a convex portion. A method for producing an electrophoretic display sheet, comprising:   An electrophoretic display device comprising: the electrophoretic display sheet according to claim 1; and a substrate provided on the back-side electrode side of the microcapsule-containing layer.   An electronic apparatus comprising the electrophoretic display device according to claim 18.

Images