JP2013218176A - Display sheet, method of manufacturing the same, display device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display sheet having excellent mechanical strength, a method of manufacturing the display sheet, a display device, and a highly reliable electronic apparatus.SOLUTION: A display device 20 includes: a substrate 12; an opposing substrate 11 oppositely arranged to the substrate 12; an adhesion layer 13 provided on the lower surface of the substrate 12; and a display layer 400 provided between the adhesion layer 13 and the opposing substrate 11. The display layer 400 includes a partition wall 9 for dividing the layer into a plurality of cells S and fluid dispersion 100 filled in the cells S. The partition wall 9 is porous, the end of the substrate 12 side is bonded with the adhesion layer 13, and the adhesion layer 13 permeates in holes 911.

Description

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

  2. Description of the Related Art Conventionally, an electrophoretic display device using particle electrophoresis has been known (see, for example, Patent Document 1). Such an electrophoretic display device is excellent in that it has portability and power saving. The electrophoretic display described in Patent Document 1 has a pair of substrates arranged opposite to each other, and a display layer provided therebetween. The display layer is divided into a plurality of cells by partition walls, and each cell is filled with a dispersion liquid in which electrophoretic particles are dispersed in a dispersion medium.

  In such an electrophoretic display device, the partition wall and the substrate are bonded via an adhesive layer (adhesive). However, since the contact area between the partition walls and the substrate (that is, the area of the top surface of the partition walls) is small, the bonding strength between the partition walls and the substrate cannot be sufficiently increased. In Patent Document 1, a groove is formed on the top surface of the partition wall to increase the contact strength with the pressure-sensitive adhesive layer, but this is still insufficient. Therefore, for example, when a relatively large stress is applied due to the deformation of the electrophoretic display device, the partition wall is peeled off from the substrate, and the electrophoretic particles move between adjacent cells via the peeled portion. . Accordingly, there is a problem that the electrophoretic particles are biased and the display characteristics are deteriorated.

Further, in Patent Document 1, since the dispersion medium cannot pass through the partition walls, for example, even when a relatively large pressure is applied to a predetermined cell by pressing the display surface, the pressure is applied to the surrounding cells. Cannot be dispersed. Therefore, there is a problem that the partition wall is peeled off from the substrate by the pressure.
As described above, Patent Document 1 has a problem that the adhesive strength between the substrate and the partition wall is originally weak, and further, due to its configuration, the partition wall is easily peeled off, that is, the mechanical strength is low.

JP 2009-271387 A

  The objective of this invention is providing the display sheet which has the outstanding mechanical strength, the manufacturing method of a display sheet, a display apparatus, and a highly reliable electronic device.

Such an object is achieved by the present invention described below.
The display sheet of the present invention includes a first substrate provided on the display surface side,
A second substrate disposed opposite the first substrate;
An adhesive layer provided on the second substrate side of the first substrate;
A display layer provided between the adhesive layer and the second substrate,
The display layer includes a partition that divides the display layer into a plurality of regions, and a dispersion liquid in which at least one kind of positively or negatively charged particles filled in each region is dispersed in a dispersion medium. Have
The partition wall is porous, and an end portion on the first substrate side is bonded to the adhesive layer, and the adhesive layer penetrates into pores in the end portion. .

  Thus, when the adhesive layer penetrates into the pores of the partition walls, the contact area between the partition walls and the adhesive layer can be increased, and these can be firmly bonded. In addition, since the dispersion medium can be moved between adjacent regions through the pores of the partition walls, the pressure in each region can be evenly distributed. Therefore, it is possible to prevent an excessive pressure (stress) from being applied to the predetermined region. Therefore, a display sheet having excellent mechanical strength can be obtained.

In the display sheet of the present invention, it is preferable that the partition wall allows the dispersion medium to pass and restricts the passage of the particles.
Thereby, since the movement of the particle | grains between area | regions is prevented, the bias | inclination of particle | grains can be prevented. Therefore, excellent display characteristics can be maintained.
In the display sheet of the present invention, it is preferable that the partition wall has a tapered shape with a width gradually decreasing toward the first substrate side.
Thereby, the aperture ratio of a display surface can be raised, raising the mechanical strength of a partition.

In the display sheet of this invention, it is preferable that the said partition is an aggregate | assembly of particle | grains and the clearance gap between particle | grains comprises the said void | hole.
Thereby, the structure of a partition becomes simple.
In the display sheet of the present invention, the adhesive layer is preferably made of a material having thermoplasticity.
Thereby, the adhesive layer can be easily softened and penetrated into the pores of the partition wall.

The display sheet manufacturing method of the present invention includes a first substrate provided on the display surface side, a second substrate disposed opposite to the first substrate, the first substrate, and the second substrate. A display layer provided between the substrate and a display sheet, comprising:
A dispersion liquid in which a porous partition is formed on the second substrate, and at least one kind of positively or negatively charged particles is dispersed in a dispersion medium in each of a plurality of regions formed by the partition. Filling, and
The first substrate having an adhesive layer formed on one surface is placed on the partition so that the adhesive layer is located on the display layer side, and the first substrate and the second substrate A step of pressing at least one of the two against the other side to bond the tip of the partition and the adhesive layer, and to allow a part of the adhesive layer to penetrate into the pores of the tip of the partition. It is characterized by that.
Thereby, the display sheet which has the outstanding mechanical strength can be manufactured easily.

In the manufacturing method of the display sheet of this invention, it is preferable to perform the process of adhere | attaching the front-end | tip part of the said partition and the said adhesive layer in the state which softened the said adhesive layer.
Thereby, an adhesive layer can be more reliably osmose | permeated in the void | hole of a partition.
In the manufacturing method of the display sheet of this invention, it has the process of replenishing a dispersion medium in the said area | region through the hole of the said partition after the process of adhere | attaching the front-end | tip part of the said partition and the said adhesive layer. It is preferable.
Thereby, when filling a dispersion liquid in each area | region, the quantity of a dispersion medium can be decreased. Therefore, it is possible to suppress the dispersion medium from adhering to the tip of the partition wall, and to bond the partition wall and the adhesive layer more firmly.

The display device of the present invention includes the display sheet of the present invention.
As a result, a display device having excellent reliability can be obtained.
In the display device of the present invention, the second substrate includes a sheet-like base portion and an electrode formed on the first substrate side of the base portion,
It is preferable to have an electrode protective layer that covers the electrode.
Thereby, corrosion of the electrode by the dispersion can be prevented.
In the display device of the present invention, it is preferable that the electrode protective layer is formed integrally with the partition wall.
Thereby, the pixel electrode protective layer can be easily formed.
An electronic apparatus according to the present invention includes the display device according to the present invention.
Thereby, an electronic device having excellent reliability can be obtained.

It is sectional drawing which shows 1st Embodiment of the display apparatus of this invention. It is a top view (top view) of the display apparatus shown in FIG. It is a partial expanded sectional view of the display apparatus shown in FIG. It is sectional drawing explaining the effect of the display apparatus shown in FIG. It is sectional drawing explaining the drive of the display apparatus shown in FIG. It is sectional drawing explaining the manufacturing method of the display apparatus shown in FIG. It is sectional drawing explaining the manufacturing method of the display apparatus shown in FIG. It is sectional drawing explaining the manufacturing method of the display apparatus shown in FIG. It is a schematic perspective view which shows 2nd Embodiment of the display apparatus of this invention. It is sectional drawing of the display sheet shown in FIG. 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.

Hereinafter, a display sheet, a display sheet manufacturing method, a 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.
1. Display Device First, a display device incorporating the display sheet of the present invention will be described.
<First Embodiment>
1 is a cross-sectional view showing a first embodiment of the display device of the present invention, FIG. 2 is a plan view (top view) of the display device shown in FIG. 1, and FIG. 3 is a partially enlarged view of the display device shown in FIG. 4 is a cross-sectional view for explaining the effect of the display device shown in FIG. 1, FIG. 5 is a cross-sectional view for explaining the driving of the display device shown in FIG. 1, and FIGS. FIG. 3 is a cross-sectional view illustrating a method for manufacturing the display device shown in FIG. 1. In the following description, for convenience of explanation, the upper side in FIG. 1 will be described as “upper” and the lower side as “lower”. Further, as shown in FIG. 1, two directions orthogonal to each other in a plan view of the display device are referred to as “X direction” and “Y direction”. The same applies to other figures.

A display device 20 (display device of the present invention) shown in FIG. 1 is an electrophoretic display device that displays a desired image using particle migration. The display device 20 includes a display sheet (front plane) 21 and a circuit board (back plane) 22.
As shown in FIG. 1, the display sheet 21 includes a substrate (first substrate) 12 including a flat base 2 and a second electrode 4 provided on the lower surface of the base 2, and a lower surface (electrode) of the substrate 12. 4 and the display layer 400 positioned between the adhesive layer 13 and the circuit board 22. In such a display sheet 21, the upper surface of the substrate 12 constitutes the display surface 121.
In addition, the display layer 400 includes partition walls 9 formed in a lattice shape and the dispersion liquid 100 filled in each cell S partitioned by the partition walls 9. The dispersion liquid 100 includes first particles (electrophoretic particles) A that are negatively charged and second particles (electrophoretic particles) B that are positively charged and have a hue different from that of the first particles A. 7 is dispersed.

On the other hand, the circuit board 22 is provided with a counter substrate (second substrate) 11 including a flat base 1 and a plurality of first electrodes 3 provided on the upper surface of the base 1, and the counter substrate 11. And a circuit (not shown). Such a circuit includes, for example, TFTs (switching elements) arranged in a matrix, gate lines and data lines formed corresponding to the TFTs, a gate driver that applies a desired voltage to the gate lines, and data A data driver that applies a desired voltage to the line, and a gate driver and a control unit that controls driving of the data driver are included.
In such a display device 20, the counter substrate 11 also serves as the second substrate of the display sheet 21.

Hereinafter, the structure of each part is demonstrated sequentially.
The base 1 and the base 2 are each composed of a sheet-like (flat plate) member, and have a function of supporting and protecting each member disposed therebetween. Each of the base portions 1 and 2 may be either flexible or hard, but is preferably flexible. By using the bases 1 and 2 having flexibility, it is possible to obtain a display device 20 having flexibility, that is, for example, a display device 20 useful in constructing electronic paper.

  In the case where the bases 1 and 2 are flexible, the constituent material includes highly transparent glass or resin. Examples of the resin include polyesters such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate), polyolefins such as polyethylene, modified polyolefins, polyamides, thermoplastic polyimides, polyethers, polyether ether ketones, polyurethanes, and chlorinated polyethylenes. These include various types of thermoplastic elastomers and the like, or copolymers, blends, polymer alloys and the like mainly containing these, and one or more of these can be used in combination.

  The average thicknesses of the bases 1 and 2 are appropriately set depending on the constituent materials, applications, etc., and are not particularly limited. As mentioned above, it is more preferable that it is about 250 micrometers or less. Thereby, size reduction (especially thickness reduction) of the display apparatus 20 can be achieved, aiming at harmony with the softness | flexibility of the display apparatus 20, and intensity | strength.

  A film-like first electrode 3 and second electrode 4 are provided on the surfaces of the bases 1 and 2 on the display layer 400 side, that is, on the upper surface of the base 1 and the lower surface of the base 2, respectively. In the present embodiment, the second electrode 4 is a common electrode, and the first electrode 3 is an individual electrode (pixel electrode connected to a TFT) divided in a matrix in the X and Y directions. . In the display device 20, a region in which one first electrode 3 and the second electrode 4 overlap constitutes one pixel.

The constituent materials of the electrodes 3 and 4 are not particularly limited as long as they are substantially conductive, for example, metal materials such as gold, silver, copper, aluminum or alloys containing these, carbon black, In a carbon-based material such as graphene, carbon nanotube, and fullerene, an electroconductive polymer material such as polyacetylene, polyfluorene, polythiophene or a derivative thereof, or a matrix resin such as polyvinyl alcohol or polycarbonate, NaCl, Cu (CF ₃ SO ₃ ) Conductive oxide materials such as ion conductive polymer materials, indium oxide (IO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide, etc. in which ionic substances such as ₂ are dispersed Various conductive materials such as, and one or more of these It can be used in conjunction seen.
The average thicknesses of the electrodes 3 and 4 are appropriately set depending on the constituent material, application, etc., and are, for example, about 10 nm or more and 100 nm or less.

  Here, among the bases 1 and 2 and the electrodes 3 and 4, the base and the electrode disposed on the display surface 121 side are each transparent, that is, substantially transparent (colorless and transparent, colored Transparent or translucent). In the present embodiment, since the upper surface of the substrate 12 constitutes the display surface 121, at least the base 2 and the second electrode 4 are substantially transparent. Thereby, the image displayed on the display device 20 can be easily recognized visually from the display surface 121 side.

A sealing portion 5 is provided between the substrate 12 and the counter substrate 11 along the edge portions thereof. The display layer 400 is hermetically sealed by the sealing portion 5. Thereby, it is possible to prevent moisture from entering the display device 20 and more reliably prevent display performance deterioration of the display device 20.
The constituent material of the sealing portion 5 is not particularly limited. For example, a thermoplastic resin such as an acrylic resin, a urethane resin, or an olefin resin, an epoxy resin, a melamine resin, or a heat such as a phenol resin. Various resin materials such as a curable resin can be used, and one or more of these can be used in combination.

An adhesive layer 13 is formed on the lower surface of the substrate 12. The adhesive layer 13 is substantially colorless and transparent, like the base 2 and the electrode 4.
Such an adhesive layer 13 is a layer used for bonding the partition wall 9 included in the display layer 400 and the substrate 12 as described later. The adhesive layer 13 also has a function of preventing contact between the electrode 4 and the dispersion medium 7, thereby preventing corrosion deterioration of the electrode 4. Further, it has a function of preventing the contact between the electrode 4 and the first and second particles A and B and preventing the first and second particles A and B from sticking to the electrode 4.

  The adhesive layer 13 is preferably made of a material that has adhesiveness and is easily softened by heat. Examples of such materials include urethane resin, urea resin, ester resin, ether resin, olefin resin such as polyethylene and polypropylene, ethylene vinyl acetate copolymer (EVA) and ethylene methyl methacrylate copolymer (EMMA), Examples include ethylene polymers such as ethylene cyclic olefin copolymer (COC resin), and thermoplastic resins such as acrylic resins and butadiene elastomers.

  In order to increase the heat resistance of the adhesive layer 13, a thermosetting material such as an epoxy compound, an isocyanate compound, a cyanoacrylate, a silane coupling agent, a melamine compound, or a phenol compound is added to the thermoplastic resin as described above. You may do it. Moreover, you may mix a fibrous fine particle and a particulate nanoparticle with a thermoplastic resin. Thereby, micro unevenness | corrugation is formed in the lower surface (surface which faces the display layer 400) of the contact bonding layer 13, and a surface area can be enlarged compared with the case of a flat surface. For this reason, the retention of the first and second particles A and B is improved, the deposition thickness of the first and second particles A and B can be increased, and high-contrast display is possible.

Here, as will be described later in the manufacturing method, in the manufacturing process of the display device 20, the adhesive layer 13 penetrates into the distal end portion of the partition wall 9 by pressing the distal end portion of the partition wall 9 against the softened adhesive layer 13. There is a process. In order to perform such a process smoothly and reliably, the softening temperature (Vicat softening temperature) of the adhesive layer 13 is preferably set to, for example, about 50 ° C. or higher and 80 ° C. or lower. Further, in order to suppress deformation of the partition wall 9 during this step, it is preferable that the adhesive layer 13 is configured to be softer than the partition wall 9. That is, it is preferable that the adhesive layer 13 is made of a material lower than the Young's modulus of the constituent material of the partition wall 9. The Young's modulus of the constituent material of the adhesive layer 13 is not particularly limited, and may vary depending on the constituent material of the partition wall 9, but is preferably about 0.01 MPa or more and 500 MPa or less, for example.
The average thickness of the adhesive layer 13 is not particularly limited, but is preferably about 1 μm or more and 5 μm or less. As a result, the adhesive layer 13 can be sufficiently permeated into the tip of the partition wall 9. Moreover, since the voltage drop between the electrodes 3 and 4 can be suppressed, the fall of the retainability of the 1st, 2nd particle | grains A and B can be suppressed.

A pixel electrode protective layer 14 is formed on the upper surface of the counter substrate 11. The pixel electrode protective layer 14 prevents contact between the electrode 3 and the dispersion medium 7, prevents corrosion deterioration of the electrode 3, and prevents contact between the electrode 3 and the first and second particles A and B. And the function of preventing the first and second particles A and B from sticking to the electrode 3. Such a pixel electrode protective layer 14 is formed integrally with the partition wall 9.
The thickness of the pixel electrode protective layer 14 is not particularly limited, but is preferably about 0.1 μm or more and 2 μm or less. Thereby, the function of the pixel electrode protective layer 14 can be exhibited, and the thickness thereof can be reduced. Therefore, the voltage drop between the electrodes 3 and 4 can be more effectively suppressed.

As shown in FIG. 1, the display layer 400 includes a partition wall 9 that is formed in a lattice shape and is a porous body, and a dispersion 100 that is filled in each cell S partitioned by the partition wall 9. Further, one electrode 3 is disposed in each cell S. The number of electrodes 3 arranged in each cell S is not limited to one, and may be two or more.
The partition wall 9 is formed on the upper surface of the counter substrate 11. As shown in FIG. 2, the partition wall 9 includes a first partition wall 91 extending in the X direction and arranged in parallel in the Y direction perpendicular to the X direction in a plan view of the display layer 400. And second partition walls 92 extending in the direction and arranged at equal intervals in the X direction, and these intersect each other.

Such a partition wall 9 is substantially colorless and transparent. Hereinafter, the configuration (shape) of the partition wall 9 will be described in detail. However, the first and second partition walls 91 and 92 have the same configuration as each other. Explanation will be made and explanation of other partition walls will be omitted.
As shown in FIG. 3, the first partition 91 is a porous body and has a large number of holes 911. The first partition 91 is formed so as to protrude from the counter substrate 11 toward the substrate 12, and the tip thereof is bonded to the adhesive layer 13. In addition, the adhesive layer 13 penetrates into the hole 911 at the tip of the first partition wall 91. Thereby, since the contact area (area which contributes to adhesion | attachment) of the 1st partition 91 and the contact bonding layer 13 can be enlarged, the 1st partition 91 and the contact bonding layer 13 can be adhere | attached firmly. Further, when the adhesive layer 13 penetrates into the irregularly formed pores 911, an anchor effect is exhibited, and thereby, the adhesive strength between the first partition wall 91 and the adhesive layer 13 is further improved.

The first partition wall 91 has a tapered shape whose width gradually decreases toward the substrate 12 side. Therefore, the first partition wall 91 is narrower at the distal end than at the proximal end. By making the first partition wall 91 tapered, the mechanical strength of the first partition wall 91 is improved and the aperture ratio of the display surface 121 is increased. It is preferable that the width W1 of the base end of the first partition wall 91 and the width W2 of the tip end satisfy the relationship 2W2 ≦ W1 ≦ 4W2. As a result, the above effects can be exhibited remarkably, the first partition wall 91 can be prevented from becoming too thick, and the enlargement of each cell S and the reduction in resolution can be prevented.
In order to increase the aperture ratio of the display surface 121, it is preferable to reduce the width W2 on the front end side as much as possible. Although it does not specifically limit as width W2, It is preferable that it is about 1 micrometer or more and 5 micrometers or less. Thereby, the aperture ratio of the display surface 121 can be increased while ensuring a sufficiently large contact area between the first partition wall 91 and the adhesive layer 13.

  Further, the height of the first partition 91 is not particularly limited, but is preferably about 5 μm or more and 50 μm or less, for example. Thereby, the shielding property of the 1st, 2nd particle | grains A and B can be ensured, shortening the moving distance of the 1st, 2nd particle | grains A and B. FIG. Therefore, high contrast display is possible while exhibiting high response speed. Further, the aspect ratio (height / width) of the first partition wall 91 is not particularly limited, but is preferably about 1 to 50.

  In such a first partition 91, the movement of the dispersion medium 7 through the holes 911 is allowed, but the movement of the first and second particles A and B through the holes 911 is restricted. Yes. That is, the dispersion medium 7 can be moved between adjacent cells S, but the first and second particles A and B cannot be moved. Thereby, the pressure (internal pressure) of each cell S can be equalized uniformly, and the stress concentration to the predetermined cell S can be prevented.

Specifically, as shown in FIG. 4, when a predetermined portion of the display surface 121 is pressed, the substrate 12 is deformed in a concave shape, and the volume in the cell S ′ corresponding to the predetermined portion is reduced, so that the internal pressure is increased. When it rises, the dispersion medium 7 in the cell S ′ moves into the adjacent cell S ″ via the partition wall 9, and the increase in the internal pressure of the cell S ′ is absorbed and relaxed (the internal pressure of each cell S is evenly distributed). Therefore, damage to the device, in particular, separation of the partition wall 9 from the adhesive layer 13 can be effectively prevented, and excellent mechanical strength can be exhibited.
In addition, since the first and second particles A and B cannot be moved from the accommodated cell S to the other cells S, the first and second particles A and B are reliably biased. And excellent image display characteristics can be maintained over time.

  The porosity (space ratio) of the partition walls 9 is not particularly limited, but is preferably about 5% or more and 50% or less. Thereby, the movement of the dispersion medium 7 as described above can be smoothly performed while sufficiently maintaining the mechanical strength of the partition wall 9. The average diameter of the holes 911 is not particularly limited as long as the movement of the first and second particles A and B can be regulated, and also varies depending on the particle diameters of the first and second particles A and B. However, for example, when the particle size of the first and second particles A and B is about 200 nm or more and 300 nm or less, it can be set to about 1 nm or more and 100 nm or less.

  The constituent material of the partition wall 9 is not particularly limited. For example, silicone resin, polyimide, epoxy resin, acrylic resin, urethane resin, urea resin, ester resin, ether resin, olefin resin such as polyethylene and polypropylene, ethylene vinyl acetate Polymers (EVA), ethylene polymers such as ethylene methyl methacrylate copolymer (EMMA), ethylene cyclic olefin copolymers (COC resin), thermoplastic resins such as butadiene elastomers, epoxy compounds, isocyanate compounds, cyano Thermosetting resins such as acrylates, silane coupling agents, melamine compounds, and phenol compounds can be used. Further, if necessary, an ultraviolet polymerization initiator may be added to impart ultraviolet curability (photocurability), or granular or non-granular inorganic oxide particles, metal particles, or the like may be mixed. Good.

  Such a partition wall 9 is preferably harder than the adhesive layer 13. That is, the partition wall 9 is preferably made of a material having a higher Young's modulus than the constituent material of the adhesive layer 13. Thereby, in the manufacturing process of the display apparatus 20, the unintentional deformation | transformation of the partition 9 can be suppressed and joining of the partition 9 and the contact bonding layer 13 can be performed more reliably. The Young's modulus of the constituent material of the partition wall 9 is not particularly limited and varies depending on the constituent material of the adhesive layer 13, but is preferably about 500 MPa or more and 10 GPa or less, for example.

When the partition wall 9 is made of a thermoplastic resin, the softening temperature (Vicat softening temperature) of the partition wall 9 is preferably higher than the softening temperature of the adhesive layer 13. The softening temperature of the partition wall 9 is not particularly limited, and is preferably about 80 ° C. or higher and 120 ° C. or lower, although it varies depending on the softening temperature of the adhesive layer 13. Further, the softening temperature of the partition wall 9 is preferably about 30 ° C. higher than the softening temperature of the adhesive layer 13. As a result, the partition wall 9 is not softened, but the adhesive layer 13 can be easily softened, and the partition wall 9 and the adhesive layer 13 can be easily and reliably bonded.
Further, the softening temperature of the partition walls 9 is preferably lower than the boiling point of the dispersion medium 7, and more preferably 20 ° C. or more lower than the boiling point of the dispersion medium 7. Thereby, it is possible to effectively prevent the dispersion medium 7 from being evaporated by heat applied to soften the partition walls 9 during the manufacture of the display device 20.

  Each cell S formed by such a partition wall 9 is filled with the dispersion liquid 100. The dispersion liquid 100 is obtained by dispersing negatively charged first particles A and positively charged second particles B having a hue different from that of the first particles A in a dispersion medium 7. The color (hue) of the first and second particles A and B is not particularly limited, and two colors are selected from achromatic colors such as white, black and gray, and chromatic colors such as red, blue and green. Any combination can be selected. For example, when realizing a monochrome display, one of the first and second particles A and B may be white and the other black.

  As the first and second particles A and B, any particles can be used as long as they have electric charges. For example, titanium oxide, zinc oxide, iron oxide, chromium oxide, zirconium oxide, etc. Oxide particles, nitride particles such as silicon nitride and titanium nitride, sulfide particles such as zinc sulfide, boride particles such as titanium boride, strontium chromate, cobalt aluminate, cuprous copper, ultra Inorganic pigment particles such as marine, organic pigment particles such as azo, quinacridone, anthraquinone, dioxazine, and perylene can be used. Alternatively, composite particles obtained by applying a pigment to the surface of resin particles made of acrylic resin, urethane resin, urea resin, epoxy resin, polystyrene, polyester, or the like can be used.

The average particle diameter of the first and second particles A and B is not particularly limited, but is preferably about 200 nm or more and 300 nm or less. If the average particle diameter is less than 200 nm, sufficient chromaticity cannot be obtained, and the display contrast may be lowered and the display may become unclear. On the contrary, when the average particle diameter exceeds 300 nm, it is necessary to increase the coloring degree of the particles themselves more than necessary, and the amount of pigments used increases, and the first and second particles A and B rapidly Movement may be difficult, and the response speed may decrease.
In addition, the average particle diameter of the 1st, 2nd particle | grains A and B is the volume average particle | grains measured with the dynamic light scattering type particle size distribution measuring apparatus (For example, product name: LB-500, the Horiba, Ltd. make). Means diameter. The same applies to white particles A described later.

  As the dispersion medium 7, one having a boiling point of 150 ° C. or higher and hardly vaporizing and having a relatively high insulating property is preferably used. Examples of the dispersion medium 7 include alcohols such as butanol and glycerin, cellosolves such as butyl cellosolve, esters such as butyl acetate, ketones such as dibutyl ketone, aliphatic hydrocarbons (liquid paraffin) such as pentane, Alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as xylene, halogenated hydrocarbons such as methylene chloride, aromatic heterocycles such as pyridine, nitriles such as acetonitrile, N, N-dimethylformamide Such as amides, carboxylate, silicone oil or other various oils, and the like, and these can be used alone or as a mixture.

  Among these, as the dispersion medium 7, those mainly composed of aliphatic hydrocarbons (liquid paraffin) or silicone oil are preferable. The dispersion medium 7 containing liquid paraffin or silicone oil as a main component is preferable because it is hydrophobic and has a high aggregation suppressing effect on the first and second particles A and B. Thereby, it can prevent or suppress more reliably that the display performance of the display apparatus 20 deteriorates with time. In addition, liquid paraffin and silicone oil are preferable from the viewpoints of excellent weather resistance and high safety because they do not have an unsaturated bond.

  The configuration of the display device 20 has been described in detail above. According to such a display device 20, since the substrate 12 and the partition wall 9 can be firmly bonded, the mechanical strength (particularly the strength against bending deformation) can be increased. Further, since the dispersion medium 7 can be moved between the cells S, it is possible to prevent the internal pressure of the cells S from being excessively increased, and the mechanical strength is also enhanced in this respect. In addition, since the substrate 12 and the partition wall 9 are firmly bonded, each cell S can be reliably separated from the other cells S, and the first and second particles A and B move between the adjacent cells S. (Going back and forth) can be prevented. Therefore, the bias of the first and second particles A and B in the display layer 400 is prevented, and excellent display characteristics can be exhibited and maintained.

Such a display device 20 is driven as follows, for example.
-Color display state of the first particle-
When a voltage is applied between the first electrode 3 and the second electrode 4 so that the first electrode 3 has a negative potential and the second electrode 4 has a positive potential, the electric field generated by the voltage application is displayed on the display layer. It acts on the first and second particles A and B in 400. Then, the negatively charged first particles A migrate to the second electrode 4 side and gather at the second electrode 4, and the positively charged second particles B migrate to the first electrode 3 side. To the first electrode 3. Thereby, as shown to Fig.5 (a), the color of the 1st particle | grains A is displayed on the display surface 121. FIG.

-Color display state of second particles-
When a voltage is applied between the first electrode 3 and the second electrode 4 so that the first electrode 3 has a positive potential and the second electrode 4 has a negative potential, the electric field generated by the voltage application is displayed on the display layer. It acts on the first and second particles A and B in 400. Then, the negatively charged first particles A migrate to the first electrode 3 side and gather on the first electrode 3, and the positively charged second particles B migrate to the second electrode 4 side. To the second electrode 4. Thereby, as shown in FIG.5 (b), the color of the 2nd particle | grains B is displayed on the display surface 121. FIG.
By selecting such a display color for each cell S (pixel), a desired image can be displayed on the display surface 121.

Next, a method for manufacturing the display device 20 will be described.
The method of manufacturing the display device 20 includes forming the display layer 400 by forming the partition wall 9 on the counter substrate 11 and filling the dispersion liquid 100 in each of the plurality of cells S formed by the partition wall 9. The substrate 12 on which the adhesive layer 13 is formed is placed on the display layer 400 so that the adhesive layer 13 is located on the display layer 400 side, and at least one of the substrate 12 and the counter substrate 11 is pressed to the other side, A step of adhering the distal end portion of the partition wall 9 to the adhesive layer 13 and allowing a part of the adhesive layer 13 to permeate into the air holes 911 at the distal end portion of the partition wall 9 Hereinafter, each step will be described in detail.

[1]
First, as shown in FIG. 6A, the counter substrate 11 is prepared, and the partition wall 9 and the pixel electrode protective layer 14 are simultaneously formed (integrally formed) on the counter substrate 11. The method for forming the partition wall 9 and the pixel electrode protective layer 14 is not particularly limited, and includes a patterning method using a photolithography technique and an etching technique, a printing method such as screen printing, and an imprint method in which irregularities are formed with a mold. As a representative example, the case of using the imprint method will be described.

First, a coating liquid prepared by dispersing thermoplastic resin (raw material) 90 ′ formed in a particle form in a solvent is prepared, and this coating liquid is applied onto the counter substrate 11 as shown in FIG. Then, the resin layer 90 which is an aggregate of the particulate thermoplastic resin 90 ′ is formed by drying and removing the solvent.
Next, as shown in FIG. 6C, a mold 900 is formed on the resin layer 90 while heating the counter substrate 12 to a temperature higher than the softening temperature of the thermoplastic resin 90 ′ (for example, about 150 to 200 ° C.). To form a partition shape on the counter substrate 11. At this time, since the counter substrate 12 is heated to a temperature equal to or higher than the softening temperature of the thermoplastic resin 90 ′, the particulate thermoplastic resin 90 ′ is softened and integrated with each other in a region near the counter substrate 11 of the resin layer 90. . That is, the region of the resin layer 90 in the vicinity of the counter substrate 11 does not maintain the shape of the thermoplastic resin 90 ′ as particles, and is further crushed by the mold 900, thereby forming a sheet with almost no gap inside. It is formed.

  On the other hand, since the heat of the counter substrate 11 is not easily transmitted to the region of the resin layer 90 on the substrate 12 side, softening of the region is prevented. Therefore, the thermoplastic resin 90 ′ is kept in a particulate form in the region of the resin layer 90 on the substrate 12 side. In addition, by performing this process while keeping the temperature of the mold 900 lower (for example, about 10 to 20 ° C.) by cooling or the like, it is possible to more reliably prevent the temperature rise in the region on the substrate 12 side of the resin layer 90. it can.

  Thereafter, although different depending on the raw material, for example, by curing the resin layer 90 by irradiating ultraviolet rays, the partition walls 9 and the pixel electrode protective layer 14 are integrally formed as shown in FIG. Since the pixel electrode protective layer 14 is composed of a portion where the thermoplastic resin is softened and re-formed into a sheet shape, the contact between the electrode 3 and the dispersion medium 7 can be reliably prevented. Since the partition wall 9 is composed of a portion in which the thermoplastic resin is maintained in a particle shape, a gap formed between the particles is porous to form pores.

  The partition wall 9 and the pixel electrode protective layer 14 are prepared by dispersing inorganic oxide nanoparticles (or metal nanoparticles) such as relatively bulky non-spherical silica and a binder in a solvent instead of the coating solution described above. It can form by performing the process similar to the above using the coating liquid which becomes. Also, by using a method of forming a hydrophobic nano-sized tunnel (void) that branches in three dimensions in the partition wall 9 by micellization using a resin having a terminal having a relatively long hydrophobic group such as an alkyl group. Also good.

[2]
Next, as shown in FIG. 7B, each cell S is filled with the dispersion liquid 100. At this time, the dispersion medium 7 is not filled to the full extent of the cell S, for example, so as to be about 60% or less of the volume of the cell S. Thereby, it can suppress effectively that the dispersion medium 7 adheres to the front-end | tip part of the partition 9, ie, the part adhering to the contact bonding layer 13, and the adhesive force with the contact bonding layer 13 falls. The filling method of the dispersion liquid 100 is not particularly limited, but for example, an inkjet method can be used. In this step, each cell S is filled with only the first and second particles A and B, and the dispersion medium 7 need not be filled.

[3]
Next, the substrate 12 on which the adhesive layer 13 is formed is prepared. The method for forming the adhesive layer 13 is not particularly limited, but a resin layer is formed by applying a coating liquid obtained by dispersing a raw material (adhesive resin material) in a solvent onto the substrate 12 (the surface of the second electrode 4). It can be formed by drying the resin layer and removing the solvent. As a coating method of the coating solution, for example, gravure coating, comma coating, wire bar coating, lip coating, die coating, screen printing, and inkjet method can be used.

[4]
Next, as shown in FIG. 7C, the substrate 12 is placed on the display layer 400 so that the adhesive layer 13 is positioned on the display layer 400 side. Thereafter, the adhesive layer 13 is heated and softened to about 50 to 80 ° C. (above the softening temperature of the adhesive layer 13), and the substrate 12 is pressed toward the counter substrate 11 in this state. As a result, the tip end of the partition wall 9 is pressure-bonded to the surface of the adhesive layer 13 and the softened adhesive layer 13 penetrates into the holes 911 of the partition wall 9. According to such a configuration, the contact area between the partition wall 9 and the adhesive layer 13 is increased, and the anchor effect is generated, whereby the partition wall 9 and the adhesive layer 13 are firmly bonded. The pressing method is not particularly limited, but a hot roll or the like can be used. According to the heat roll, the heating (softening) of the adhesive layer 13 and the pressing of the substrate 12 to the counter substrate 11 can be performed simultaneously.

[5]
Next, as shown in FIG. 8A, the dispersion medium 7 is filled and replenished into each cell S via the partition walls 9, and each cell S is filled with the dispersion liquid 100 and air is removed. The method of filling the dispersion medium 7 is not particularly limited. For example, in the step of [4], the sheet obtained in the step [4] is immersed in a bath filled with the dispersion medium 7. The obtained sheet is placed in a vacuum (reduced pressure) environment, and a reduced pressure injection method in which the dispersion medium 7 is injected through the partition walls 9 or a pressurized injection method in which the dispersion medium 7 pressurized through the partition walls is forcibly injected. Etc. can be used.
[6]
Next, as illustrated in FIG. 8B, the display device 20 is obtained by forming the sealing portion 5 around the display layer 400. According to such a manufacturing method, the partition wall 9 and the substrate 12 are firmly bonded, and the display device 20 having excellent mechanical strength can be manufactured.

Second Embodiment
FIG. 9 is a schematic perspective view showing a second embodiment of the display device of the present invention, and FIG. 10 is a cross-sectional view of the display sheet shown in FIG.
Hereinafter, the second embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.
The display device according to the second embodiment is the same as that of the first embodiment except that the display sheet is configured as a separate body.

As shown in FIG. 9, the display device 20B of this embodiment includes a display sheet 21B and a writing device 22B.
As shown in FIG. 10, the display sheet 21B includes a substrate (first substrate) 12B, a substrate (second substrate) 11B disposed opposite to the substrate 12B, and an adhesive layer 13 formed on the lower surface of the substrate 12B. And a display layer 400 provided between the substrates 12B and 11B, and a sealing portion 5 for sealing the display layer 400. Since the substrates 12B and 11B have the same configuration as the base 2 of the substrate 12 of the first embodiment described above, description thereof is omitted.

  The writing device 22B is a device used when writing a desired image (pattern, color, character, picture, or a combination thereof) on the display sheet 21B. As shown in FIG. 9, the writing device 22B is common to a pedestal 221B, a sheet-like common electrode 222B provided on the pedestal 221B, and a writing pen (input tool) 224B provided with a partial electrode 223B at the tip. Voltage applying means 225B for applying a voltage between the electrode 222B and the partial electrode 223B.

Such a display device 20B is used as follows, for example.
First, the display sheet 21B in which the entire display surface 121 is in a white display state is placed on the common electrode 222B of the writing device 22B with the display surface 121 facing upward. Next, a voltage at which the partial electrode 223B side has a low potential is applied between the common electrode 222B and the partial electrode 223B by the voltage applying unit 225B. In this state, when the writing pen 224B is moved along a desired locus while being in contact with the display surface 121, migration of the first and second particles A and B occurs in the cell corresponding to the locus, and the display color is white. To black.

According to such a display device 20B, a desired character or the like can be drawn on the display surface 121 of the display sheet 21B with the same feeling as drawing a character or the like on a paper with a pencil. Therefore, the operability (operation feeling) of the display device 20B is improved.
Also according to the third embodiment, the same effects as those of the first embodiment described above can be exhibited.

Each of the display devices 20 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. 11 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. 11 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 electronic paper 600, the display unit 602 includes the display device 20 as described above.

Next, an embodiment when the electronic apparatus of the present invention is applied to a display will be described.
FIG. 12 is a diagram showing an embodiment when the electronic apparatus of the present invention is applied to a display. Among these, (a) in FIG. 12 is a sectional view and (b) is a plan view.
A display (display device) 800 shown in FIG. 12 includes a main body 801 and an electronic paper 600 that is detachably attached to the main body 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 its side (right side in FIG. 12A), and two pairs of conveying rollers 802a and 802b are provided inside. Yes. 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. 12B), and a transparent glass plate 804 is fitted in 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 of the electronic paper 600 in the insertion direction (left side in FIG. 12A), and the electronic paper 600 is installed in the main body 801 inside the main body 801. A socket 807 to which the terminal portion 806 is connected in the state 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. This improves convenience.

  As described above, the display sheet, the display sheet manufacturing method, the display device, and the electronic apparatus according to the present invention have been described based on the illustrated embodiment.However, the present invention is not limited to this, and the configuration of each part is as follows. Any structure having a similar function can be substituted. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment mentioned above suitably.

  In the above-described embodiment, the partition walls 9 have a lattice shape. However, the configuration (planar shape) of the partition walls 9 is not particularly limited. For example, it may be configured in a honeycomb shape, or may be configured by a plurality of partition walls extending in the X direction and arranged at intervals in the Y direction. In the former case, the mechanical strength is further increased, and in the latter case, the aperture ratio can be further increased.

  1, 2 ... Base 100 ... Dispersion 11B, 12B ... Substrate 11 ... Counter substrate 12 ... Substrate 121 ... Display surface 13 ... Adhesive layer 14 ... Pixel electrode protective layer 20 ... Display device 20B ... … Display device 21 …… Display sheet 21B …… Display sheet 22 …… Circuit board 22B …… Writing device 221B …… Pedestal 222B …… Common electrode 223B …… Partial electrode 224B …… Writing pen 225B …… Voltage applying means 3, 4 ... Electrode 400 ... Display layer 5 ... Sealing part 7 ... Dispersion medium 600 ... Electronic paper 601 ... Main body 602 ... Display unit 800 ... Display 801 ... Main body part 802a, 802b ... Conveying roller Pair 803 …… Hole portion 804 …… Transparent glass plate 805 …… Insertion slot 806 …… Terminal portion 807 …… Socket 80 …… Controller 809 …… Operation unit 9 …… Partition wall 90… Resin layer 90 ′ …… Thermoplastic resin 900 …… Mold 91 …… First partition wall 92 …… Second partition wall 911 …… Hole A …… First particle B ... Second particle S ... Cell (region) W1, W2 ... Width

Claims (12)

A first substrate provided on the display surface side;
A second substrate disposed opposite the first substrate;
An adhesive layer provided on the second substrate side of the first substrate;
A display layer provided between the adhesive layer and the second substrate,
The display layer includes a partition that divides the display layer into a plurality of regions, and a dispersion liquid in which at least one kind of positively or negatively charged particles filled in each region is dispersed in a dispersion medium. Have
The partition wall is porous, and an end portion on the first substrate side is bonded to the adhesive layer, and the adhesive layer penetrates into pores in the end portion. Display sheet.   The display sheet according to claim 1, wherein the partition wall allows passage of the dispersion medium and restricts passage of the particles.   The display sheet according to claim 1, wherein the partition wall has a tapered shape in which a width gradually decreases toward the first substrate side.   The display sheet according to any one of claims 1 to 3, wherein the partition wall is an aggregate of particles, and a gap between the particles forms the pores.   The display sheet according to claim 1, wherein the adhesive layer is made of a thermoplastic material. A first substrate provided on the display surface side, a second substrate disposed opposite to the first substrate, and a display provided between the first substrate and the second substrate A display sheet having a layer,
A dispersion liquid in which a porous partition is formed on the second substrate, and at least one kind of positively or negatively charged particles is dispersed in a dispersion medium in each of a plurality of regions formed by the partition. Filling, and
The first substrate having an adhesive layer formed on one surface is placed on the partition so that the adhesive layer is located on the display layer side, and the first substrate and the second substrate A step of pressing at least one of the two against the other side to bond the tip of the partition and the adhesive layer, and to allow a part of the adhesive layer to penetrate into the pores of the tip of the partition. A manufacturing method of a display sheet,   The method for manufacturing a display sheet according to claim 6, wherein the step of bonding the tip of the partition and the adhesive layer is performed in a state where the adhesive layer is softened.   8. The display sheet according to claim 6, further comprising a step of replenishing a dispersion medium in the region through pores of the partition wall after the step of bonding the leading end portion of the partition wall and the adhesive layer. Manufacturing method.   A display device comprising the display sheet according to claim 1. The second substrate has a sheet-like base and an electrode formed on the first substrate side of the base,
The display device according to claim 9, further comprising an electrode protective layer that covers the electrode.   The display device according to claim 10, wherein the electrode protective layer is formed integrally with the partition wall.   An electronic apparatus comprising the display device according to claim 9.

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