CN100421022C - Display medium and method of manufacturing display medium - Google Patents

Abstract

An object of the present invention is to provide a display medium which obtains excellent display performance by suppressing color unevenness and a decrease in contrast and which can be manufactured in a simple method, and a method of manufacturing the same. Solution to Problem: In the display medium (10) according to the present invention, the partition for partitioning the electrophoretic medium (30) is formed of a fluid substance. Thus, when the entire display medium (10) is bent, the partition does not suffer damage when the display medium (10) is bent. Since the separator is formed due to the phase separation of the electrophoretic medium (30) and the separation medium (20), the display medium (10) can be obtained more easily without complicated processes, thereby reducing production costs.

Description

Display medium and method of manufacturing display medium

technical field

[0001]

The present invention relates to a display medium, an electrophoretic display, and a method of manufacturing the display medium. In particular, the present invention relates to a display medium capable of suppressing irregular color development to improve its display performance and capable of high-brightness color display, an electrophoretic display using the display medium, and a method of manufacturing the display medium.

Background technique

[0002]

As is well known in the art, a display medium using electrophoresis is a rewritable medium for displaying images. However, in these electrophoretic display media, charged particles in one pixel (particles that migrate in the electrophoretic medium when an electric field is generated) can be transferred into adjacent pixels, resulting in color unevenness or a decrease in contrast. Many of these display media have been provided with spacers between adjacent pixels to prevent the transfer of charged particles between different pixels.

[0003]

For example, Japanese Laid-Open No. 2003-202601 (Patent Document 1) proposes an image display having a partition. By coating a photosensitive paste having a photosensitive resin composition on a substrate, exposing only those areas of the paste corresponding to spacers with a photomask to harden the paste, and then developing and drying the paste, thereby Form the dividers.

[0004]

There are also some fully flexible display media. FIG. 1( a ) and FIG. 1( b ) illustrate the problems in such a flexible display medium 100 when the display medium 100 is configured with a solid spacer 140 . FIG. 1( a ) shows the display medium 100 in an uncurved state, while FIG. 1( b ) shows the display medium 100 in a curved state. The display medium 100 comprises a substrate 120, a substrate 130 arranged substantially parallel to the substrate 120, a plurality of linear electrodes 120a and 130a respectively arranged in relation to the substrate 120 and the substrate 130 in a simple matrix of orthogonal lines, and arranged on the substrate 120. A solid separator 140 between the sheet 120 and the substrate 130, and an electrophoretic medium (not shown) with dispersed charged particles filling the gap between the substrate 120 and the substrate 130.

[0005]

As shown in FIG. 1( b ), when the flexible display medium 100 provided with the solid spacer 140 as described in Patent Document 1 is bent, the spacer 140 is deformed and broken or separated at the bonded area.

[0006]

To solve this problem, Japanese Patent Laid-Open No. 2003-15166 (Patent Document 2) describes an electrophoretic display by providing a flexible surface on a substrate on which no spacer is formed and pressing the spacer against the surface to seal The gap between the spacer and the substrate. In the electrophoretic display disclosed in Patent Document 2, the flexible surface layer suppresses deformation of the separator itself, thereby suppressing damage to the separator.

[0007]

It has also been proposed to use an electrophoretic display medium capable of displaying color images as a rewritable display medium. For example, Japanese Patent Laid-Open No. 2003-108035 (Patent Document 3) discloses a diffuse reflection type color display that can be formed by forming a color filter at a position corresponding to an electrode provided on a first substrate in a display medium. monitor to display color images. Japanese Patent Laid-Open No. 2000-35769 (Patent Document 4) describes another display in which microcapsules of three different colors are injected into three types of nozzles by using an inkjet system and each Manufactured by spraying a microcapsule through a nozzle on the

Patent Document 1: 2003-202601;

Patent Document 2: 2003-15166;

Patent Document 3: 2003-108035;

Patent Document 4: 2000-35769.

Contents of the invention

The problem to be solved by the invention

[0008]

However, although the electrophoretic display disclosed in Patent Document 2 suppresses damage to the spacer when the substrate is bent, configuring a flexible surface requires an increase in the number of its constituent parts and complicates the manufacturing process, resulting in increased production costs.

[0009]

The process to place the solid divider is also often complex as it involves many steps. Furthermore, once the solid spacers are placed on the substrate, it is difficult to fill all the pixels with a uniform content of electrophoretic medium, resulting in non-uniform colors and low contrast.

[0010]

In such reflective display media using electrophoresis, disposing a spacer layer of a color filter as described in Patent Document 3 results in a decrease in image brightness (image darkening) and a decrease in color quality. Furthermore, in the method disclosed in Patent Document 4, it is difficult to properly align the microcapsules because it is difficult to control when the microcapsules are ejected.

[0011]

In order to solve the above-mentioned problems, an object of the present invention is to provide a display medium which obtains excellent display performance by suppressing occurrence of color unevenness and decrease in contrast and which can be manufactured in a simple manner, and a method of manufacturing the display medium.

[0012]

Another object of the present invention is to provide a display medium which can be manufactured by a simple method and which can display a high-brightness color image, an electrophoretic display having the display medium, and a method of manufacturing the display medium.

way of solving the problem

[0013]

These objects are achieved by a display medium as claimed in claim 1, which comprises a pair of substrates spaced apart from each other and arranged substantially in parallel, and an electrophoretic medium which is arranged between the pair of substrates and contains charged particles, by means of The electric field generated between the sheet pairs causes the charged particles contained in the electrophoretic medium to migrate, thereby switching the display state. The display medium further includes a separation medium having fluidity at least at room temperature and phase-separated from the electrophoretic medium, the separation medium being in a phase-separated state separated from the electrophoretic medium, wherein the separation medium is provided between the pair of substrates as a spacer to separate the electrophoretic medium.

[0014]

The display medium of claim 2 further comprising a first surface treatment moiety having a greater affinity for the electrophoretic medium than the separation medium, and a second surface treatment having a greater affinity for the separation medium than the electrophoretic medium part, wherein the second surface treatment part is provided on the surface of at least one substrate in the pair of substrates in contact with the separation medium according to the shape of the separation medium, and the first surface treatment part is provided on at least one substrate in the pair of substrates The surface in contact with the electrophoretic medium is used to set the position of the electrophoretic medium.

[0015]

In claim 2, "the second surface treatment part is provided on the surface of at least one substrate in the pair of substrates in contact with the separation medium according to the shape of the separation medium, and the first surface treatment part is provided on at least one of the pair of substrates. On the surface of a substrate that is in contact with the electrophoretic medium is used to set the electrophoretic medium" means that the first surface treatment part and the second surface treatment part are both arranged on one of the pair of substrates, the first surface treatment Both the first surface treatment and the second surface treatment are provided on two substrates, or the first surface treatment and the second surface treatment are provided on different substrates.

[0016]

In the display medium according to claim 3, the first surface treatment portion and the second surface treatment portion are transparent and provided on the substrate which is viewed as a display surface by a user.

[0017]

In the display medium according to claim 4, both the electrophoretic medium and the separation medium are mutually insoluble solvents, or solutions containing mutually insoluble solvents.

[0018]

In claim 4, "both the electrophoretic medium and the separation medium are mutually insoluble solvents, or a solution containing mutually insoluble solvents" means that the mixture of the electrophoretic medium and the separation medium is a mixture of mutually insoluble solvents, containing A mixture of solutions of mutually immiscible solvents, or a mixture of mutually immiscible solvents and a solution comprising mutually immiscible solvents.

[0019]

In the display medium as claimed in claim 5, one of the electrophoretic medium and the separation medium is water or an aqueous solution, and the other is a water-insoluble solvent or a solution containing such a solvent.

[0020]

In the display medium according to claim 6, the separation medium is water or an aqueous solution, and the electrophoretic medium is a water-insoluble solvent or a solution containing such a solvent.

[0021]

In the display medium according to claim 7, the water-insoluble solvent is an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, silicone oil, or high-purity petroleum, or a mixture of two or more of the above.

[0022]

In the display medium according to claim 8, the partition medium is colorless or white.

[0023]

In a display medium as claimed in claim 9, the surfaces of the charged particles have a greater affinity for the electrophoretic medium than for the separation medium.

[0024]

The display medium according to claim 10, further comprising a pair of electrodes respectively provided on opposite surfaces of the pair of substrates, and a protective film having flow resistance and provided on opposite surfaces of the respective electrodes.

[0025]

In the display medium according to claim 11, the protective film has a fluorine-containing compound.

[0026]

In the display medium according to claim 12, the pair of substrates are both flexible.

[0027]

The display medium according to claim 13, further comprising spacer particles provided between the pair of substrates to maintain a predetermined distance between the pair of substrates.

[0028]

In a display medium as claimed in claim 14, the surfaces of the spacer particles have a greater affinity for the spacer medium than for the electrophoretic medium.

[0029]

The display medium according to claim 15, further comprising a block-shaped fixing spacer provided between the pair of substrates and fixed to at least one substrate of the pair of substrates.

[0030]

In the display medium according to claim 16, the fixed spacer is fixed to one substrate of the pair of substrates and separated from the other substrate.

[0031]

In the display medium according to claim 17, the partition medium is provided between the fixed spacer and the substrate separated from the fixed spacer.

[0032]

In the display medium according to claim 18, the surface of the fixed partition facing the substrate separated therefrom, or the surface corresponding to the above-mentioned surface of the substrate on the side separated from the fixed partition faces the partition medium. The affinity is greater than the affinity for the electrophoretic medium.

[0033]

A display medium as claimed in claim 19 comprising a pair of substrates spaced apart from each other and arranged substantially in parallel, charged particles, and an electrophoretic medium disposed between the pair of substrates and containing charged particles, by means of a pair of substrates generated between the pair of substrates. The electric field causes charged particles contained in the electrophoretic medium to migrate, thereby switching the display state, wherein the electrophoretic medium includes a first medium exhibiting a first color, and a second medium exhibiting a second color, and the second medium is capable of displaying at least at room temperature. Phase separation occurs from the first medium, and the second medium and the first medium that are phase-separated from each other form a predetermined pattern when they are in a phase-separated state from each other.

[0034]

The display medium of claim 20 further comprising a first surface treatment moiety having a greater affinity for the first medium than for the second medium, and a greater affinity for the second medium than for the first medium. The second surface treatment portion, wherein both the first surface treatment portion and the second surface treatment portion are provided on the surface of at least one substrate of the pair of substrates in contact with the electrophoretic medium according to a prescribed pattern.

[0035]

In claim 20, "both the first surface treatment part and the second surface treatment part are provided on the surface of at least one substrate of the pair of substrates in contact with the electrophoretic medium according to a prescribed pattern" means the first surface treatment part and the The second surface treatment part is provided on only one of the pair of substrates according to a prescribed pattern, the first surface treatment part and the second surface treatment part are provided on both substrates according to a prescribed pattern, or the first surface treatment part and the second surface treatment portion are formed on different substrates according to a prescribed pattern.

[0036]

In the display medium according to claim 21, the first medium and the second medium are mutually insoluble solvents, or solutions containing mutually insoluble solvents.

[0037]

In claim 21, "the first medium and the second medium are mutually insoluble solvents, or a solution containing mutually insoluble solvents" means that the mixture of the first medium and the second medium is mutually insoluble solvents A mixture, a mixture of solutions comprising mutually insoluble solvents, or a mixture of mutually insoluble solvents and solutions comprising mutually insoluble solvents.

[0038]

In the display medium according to claim 22, one of the first medium and the second medium is water or an aqueous solution, and the other is a water-insoluble solvent or a solution containing a water-insoluble solvent.

[0039]

In the display medium according to claim 23, the water is distilled water or deionized water.

[0040]

In the display medium as claimed in claim 24, the water-insoluble solvent is an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, silicone oil, or high-purity petroleum, or a mixture comprising two or more of the above.

[0041]

In the display medium according to claim 25, the charged particles include first particles whose surface has an affinity for the first medium greater than that for the second medium, and second particles whose surface has an affinity for the second medium. The resultant force is greater than the affinity for the first medium.

[0042]

In the display medium according to claim 26, the first particles and the second particles have different colors.

[0043]

In the display medium according to claim 27, the first medium and the second medium have different colors.

[0044]

A display medium as claimed in claim 28 further comprising a pair of electrodes respectively provided on opposite surfaces of the pair of substrates, and a protective film having flow resistance and provided on opposite surfaces of the respective electrodes.

[0045]

In the display medium according to claim 29, the protective film has a fluorine-containing compound.

[0046]

In the display medium as claimed in claim 30, each of the pair of substrates is flexible.

[0047]

The display medium according to claim 31, further comprising a spacer provided between the pair of substrates to maintain a predetermined distance between the pair of substrates.

[0048]

In the display medium according to claim 32, one of the pair of electrodes includes first electrodes and second electrodes which are spaced apart from each other and arranged alternately, wherein the first medium is arranged at a position corresponding to the first electrodes, and the second electrode is arranged at a position corresponding to the first electrodes. The two mediums are arranged at positions corresponding to the second electrodes to form a prescribed pattern.

[0049]

The display medium of claim 33 further comprising a first surface treatment moiety having a greater affinity for the first medium than for the second medium, and a greater affinity for the second medium than for the first medium. The second surface treatment part, wherein the first surface treatment part is provided on the surface of the first electrode, and the second surface treatment part is provided on the surface of the second electrode.

[0050]

The electrophoretic display as claimed in claim 34 includes the display medium as claimed in claim 32, and an electric field control unit for independently controlling the electric field generated between the first electrode and the electrode opposite to the first electrode, and an electric field generated between the second electrode and an electrode opposite to the second electrode.

[0051]

In the electrophoretic display according to claim 35, the electric field control unit independently controls the electric field by applying voltages of different driving waveforms to the first electrode or the second electrode.

[0052]

In claim 35, "applying voltages of different driving waveforms" includes a method of applying voltages of driving waveforms having different amplitudes and/or a method of applying voltages of driving waveforms of different pulse widths.

[0053]

A method of manufacturing a display medium as set forth in claim 36 is a method of manufacturing the display medium comprising a pair of substrates spaced apart from each other and arranged substantially in parallel, and a substrate provided between the pair of substrates and containing charged particles. The electrophoretic medium, with the help of the electric field generated between the substrate pair, causes the charged particles contained in the electrophoretic medium to migrate, thereby switching the display state. The manufacturing method includes a medium layout process for disposing a mixture of an electrophoretic medium and a separation medium having fluidity at least at room temperature and separating from the electrophoretic medium on at least one of the pair of substrates and the other substrate. On the face of the opposite side; and a spacer forming process, which is provided as a spacer by phase-separating the electrophoretic medium and the spacer medium in the mixture provided on the surface of at least one of the substrate pairs in the medium layout process. The separation medium of the piece is used to separate the electrophoretic medium.

[0054]

In claim 36, "the mixture of the electrophoretic medium and the separation medium which has fluidity at least at room temperature and is separated from the electrophoretic medium is provided on the surface of at least one substrate of the pair of substrates on the opposite side to the other substrate. "on" includes a method of disposing a mixture of an electrophoretic medium and a separation medium having fluidity at least at room temperature and separating from the electrophoretic medium on the surface of one of the pair of substrates opposite to the other substrate, and placing the electrophoretic A method in which a dielectric is placed between a pair of substrates.

[0055]

The method of manufacturing a display medium as claimed in claim 37, further comprising a surface treatment step for providing a first surface treatment portion having an affinity for the electrophoretic medium greater than that for the separation medium, which is provided in the pair of substrates. At least one of the substrates on the side opposite to the other substrate at a position for disposing the electrophoretic medium, and providing a second surface treatment portion having a greater affinity for the separation medium than for the electrophoretic medium, which is provided At a position corresponding to the shape of the separation medium on the surface of at least one substrate of the substrate pair opposite to the other substrate.

[0056]

In the method of manufacturing a display medium as claimed in claim 38, the charged particles have greater affinity for the electrophoretic medium than for the separation medium.

[0057]

The method of manufacturing a display medium as claimed in claim 39, further comprising a protective film forming step by coating a liquid containing a fluorine-containing compound on the surface of the electrode pair before treating the surface of the substrate with the surface treatment step, Thus, a flow-resistant protective film is formed on the surfaces of the electrode pairs.

[0058]

A method of manufacturing a display medium as claimed in claim 40 is a method of manufacturing the display medium comprising a pair of substrates spaced apart from each other and arranged substantially in parallel, charged particles, and a pair of substrates disposed between the pair of substrates and The electrophoretic medium containing charged particles migrates the charged particles contained in the electrophoretic medium by means of an electric field generated between the pair of substrates to switch the display state. The manufacturing method includes a medium layout process for disposing an electrophoretic medium comprising a mixture of a first medium exhibiting a first color and a second medium exhibiting a second color on at least one substrate of the substrate pair. On the opposite side of the other substrate, the second medium can be phase-separated from the first medium at least at room temperature; The second medium is phase-separated to form a predetermined pattern with the first medium and the second medium.

[0059]

In claim 40, "disposing the electrophoretic medium on the surface of at least one substrate of the substrate pair opposite to the other substrate" includes disposing the electrophoretic medium on the side of the substrate pair opposite to the other substrate. A method on the surface of a substrate, and a method of disposing an electrophoretic medium between a pair of substrates.

[0060]

In the method of manufacturing a display medium as claimed in claim 41, one of the pair of electrodes respectively provided on the opposite faces of the pair of substrates includes first electrodes and second electrodes spaced apart from each other and alternately arranged. The manufacturing method includes a surface treatment process for providing, on the surface of the first electrode, a first surface treatment portion having an affinity for the first medium greater than that for the second medium, and providing, on the surface of the second electrode, The second surface treatment part having an affinity for the second medium greater than that for the first medium, wherein the medium separation process forms a predetermined pattern by selectively disposing the electrophoretic medium so that a phase occurs between the first medium and the second medium. When separating, the first medium is set at the position corresponding to the first electrode, and the second medium is set at the position corresponding to the second electrode.

[0061]

The method of manufacturing a display medium according to claim 42, further comprising a protective film forming step of coating the surfaces of the pair of electrodes with a coating containing Fluorine compound liquid to form a flow-resistant protective film on the surface of the electrode pair.

[0062]

In the method of manufacturing a display medium as claimed in claim 43, the charged particles include first particles having an affinity for the first medium greater than that for the second medium, and an affinity for the second medium greater than that for the first medium. Medium affinity for the second particle.

Invention effect

[0063]

In the display medium according to claim 1, the electrophoretic medium containing charged particles is provided between the pair of substrates spaced apart from each other and arranged substantially in parallel. When an electric field is generated between the pair of substrates, the charged particles contained in the electrophoretic medium migrate, thereby switching the display state. In such display media, a separation medium having fluidity at least at room temperature and being phase-separated from the electrophoretic medium is provided between the pair of substrates as a spacer for separating the electrophoretic medium.

[0064]

Thus, the separator for separating the electrophoretic medium is formed of a fluid substance. Therefore, when the entire display medium is bent, the spacer is not damaged when the display medium is bent.

[0065]

Since the separator is formed by phase separation between the electrophoretic medium and the separation medium, the display medium can be obtained easily without complicated processes, thereby reducing production costs.

[0066]

In addition, since the separator is formed by phase separation between the electrophoretic medium and the separation medium, the electrophoretic medium can be arranged more uniformly than if the electrophoretic medium (containing charged particles) is arranged after the separator is formed. Thus, a display medium capable of suppressing uneven color and having a high contrast ratio can be obtained.

[0067]

In the display medium according to claim 2, in addition to the effect of the display medium according to claim 1, the first surface treatment portion having an affinity for the electrophoretic medium greater than that for the separation medium is provided in the pair of substrates On the surface of at least one of the substrates where the electrophoretic medium is disposed, a second surface treatment portion having an affinity for the separation medium greater than that for the electrophoretic medium is provided on at least one of the pair of substrates according to the shape of the separation medium. The surface of the substrate in contact with the separating medium. Thus, the display medium facilitates selectively disposing the electrophoretic medium and the separation medium at positions where the first surface treatment portion and the second surface treatment portion are provided.

[0068]

In the display medium according to claim 3, in addition to the effect of the display medium according to claim 2, the first surface treatment part and the second surface treatment part are transparent and provided on the substrate which is regarded as the display surface by the user . Therefore, the existence of the first surface treatment part and the second surface treatment part not only does not affect the definition, but also precisely separates the electrophoretic medium on the view plane, so that the user can see high-quality images.

[0069]

In the display medium according to claim 4, in addition to the function of the display medium according to claim 1, both the electrophoretic medium and the separation medium are mutually insoluble solvents or solutions containing mutually insoluble solvents. Thus, the electrophoretic medium and the separation medium can be phase-separated more easily.

[0070]

In the display medium as claimed in claim 5, in addition to the effect of the display medium as claimed in claim 4, one of the electrophoretic medium and the separation medium is water or an aqueous solution, and the other is a water-insoluble solvent or Solutions containing this solvent. Thus, the electrophoretic medium and the separation medium can be phase-separated more easily, and a medium using water or an aqueous solution is easier to obtain.

[0071]

In the display medium as claimed in claim 6, in addition to the function of the display medium as claimed in claim 4, the separation medium is water or an aqueous solution, and the electrophoretic medium is a water-insoluble solvent or a solution containing such a solvent. Thus, the electrophoretic medium and the separation medium can be phase-separated more easily. In addition, when the electrophoretic medium must be insulating, it is advantageous to use a water-insoluble solvent or a solution containing the solvent as the electrophoretic medium, thereby improving the quality of the display medium.

[0072]

In the display medium as claimed in claim 7, in addition to the effect of the display medium as claimed in claim 4, the water-insoluble solvent is an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a hydrogenated hydrocarbon solvent, silicone oil, or a high-purity Petroleum, or a mixture of two or more of the above. This structure is advantageous when the electrophoretic medium must have insulating properties, thereby improving the quality of the display medium.

[0073]

In the display medium according to claim 8, in addition to the function of the display medium according to claim 1, the partition medium is colorless or white. Thus, the color of the partition formed by the partition medium does not adversely affect the image displayed on the display medium.

[0074]

In the display medium as claimed in claim 10, in addition to the effect of the display medium as claimed in claim 1, the electrode pairs are respectively arranged on the opposite surfaces of the substrate pair, and the protective film with flow resistance is arranged on each electrode. On the opposite side. Thus, this structure can prevent direct contact between the liquid electrophoretic medium and the electrodes, thereby preventing deterioration of the electrodes.

[0075]

In the display medium according to claim 11, in addition to the effect of the display medium according to claim 10, the protective film has a fluorine-containing compound. Thus, this structure can more effectively prevent direct contact between the electrophoretic medium and the electrode, thereby more effectively preventing deterioration of the electrode.

[0076]

In the display medium according to claim 12, in addition to the function of the display medium according to claim 1, the pair of substrates is flexible. Thus, a more flexible entire display medium can be produced.

[0077]

In the display medium according to claim 13, in addition to the function of the display medium according to claim 1, the spacer particles maintain at least a predetermined distance between the pair of substrates. Thus, it is possible to reliably prevent excessive deformation in the electrode when a force is applied to its surface, thereby reliably preventing the electrode from being damaged. This structure is particularly effective in preventing the substrates from coming into contact with each other due to slack when the substrates are bent, thereby more effectively preventing image deterioration and display medium damage.

[0078]

In the display medium according to claim 14, in addition to the effect of the display medium according to claim 13, the surfaces of the spacer particles have a greater affinity for the partition medium than for the electrophoretic medium. Thus, the spacer particles can be effectively arranged in the separation medium. In addition, the spacer particles dispersed in the separation medium can be suppressed from migrating to the electrophoretic medium, thereby maintaining stable image quality.

[0079]

In the display medium according to claim 15, in addition to the function of the display medium according to claim 1, a block-shaped fixed spacer is fixed to at least one of the pair of substrates. Thus, the structure can more reliably prevent excessive deformation in the substrate when a force is applied to its surface, thereby reliably preventing the substrate from being damaged. This structure is particularly effective in preventing the substrates from coming into contact with each other due to slack when the substrates are bent, thereby more reliably preventing deterioration of image quality and damage to the display medium. In addition, the structure in which the block-shaped fixed spacer is fixed to one substrate and separated from the other substrate makes the spacer particularly resistant to damage even when the display medium is bent.

[0080]

In the display medium according to claim 16, in addition to the function of the display medium according to claim 15, the block-shaped fixed spacer is fixed to one substrate of the pair of substrates and separated from the other substrate. Thus, even when the display medium is bent, the separator is not broken. Furthermore, by separating the fixed spacer from one of the substrates, the space formed therebetween enables the electrophoretic medium (containing charged particles) to be uniformly disposed.

[0081]

In the display medium according to claim 17, in addition to the function of the display medium according to claim 16, the partition medium is provided between the fixed spacer and the substrate separated from the fixed spacer. Thus, the partition formed by the partition medium can inhibit the migration of charged particles in the electrophoretic medium to other regions in the electrophoretic medium.

[0082]

In the display medium according to claim 18, in addition to the function of the display medium according to claim 16, the surface of the fixed partition facing the substrate separated therefrom, or the substrate on the side separated from the fixed partition The surface of the sheet corresponding to the aforementioned surface has a greater affinity for the separation medium than for the electrophoretic medium. Thus, by causing the electrophoretic medium and the separation medium to phase-separate, the separation medium can be selectively arranged in the space created by the separation between the fixed spacer and the substrate. By arranging the separation medium between the fixed spacer and the substrate separated from the fixed spacer, the spacer formed of the separation medium can suppress migration of charged particles in the electrophoretic medium to other regions in the electrophoretic medium.

[0083]

In the display medium as claimed in claim 19, the electrophoretic medium containing charged particles is provided between the pair of substrates spaced apart from each other and arranged substantially in parallel. When an electric field is generated between the pair of substrates, the charged particles contained in the electrophoretic medium migrate, thereby switching the display state. In such display media, the electrophoretic medium includes a first medium exhibiting a first color, and a second medium exhibiting a second color. The second medium is capable of phase separating from the first medium at least at room temperature. The second medium and the first medium separated from each other form a predetermined pattern. Specifically, in the display medium according to claim 19, the electrophoretic medium between the substrates is formed into a predetermined pattern with the first medium and the second medium at least at room temperature. Then, when the color of the first medium (first color) and the color of the second medium (second color) are different or when the color of the first medium and the color of the second medium are the same but the color of the charged particles contained in the medium At the same time, a color display can be formed on the display medium by arranging a predetermined pattern capable of forming each pixel by using adjacent regions of the first medium and the second medium. Since the first medium and the second medium constituting the electrophoretic medium can phase-separate at least at room temperature in this case, a display medium capable of displaying a color image can be obtained relatively easily. In addition, in such color display media, the colors of the first and second media function as color filters to obtain excellent brightness and color, thereby maintaining high-quality images, even in electrophoretic reflective display media in this way.

[0084]

In the display medium according to claim 20, in addition to the effect of the display medium according to claim 19, the first surface treatment part having an affinity for the first medium greater than that for the second medium and the second surface treatment part The second surface treatment portions having a greater affinity for the medium than for the first medium are provided in accordance with a prescribed pattern on the surface of at least one of the pair of substrates in contact with the electrophoretic medium. By providing the first medium and the second medium on the surface of the substrate on which the first processing portion and the second processing portion are provided, the first medium and the second medium can be selectively arranged according to a prescribed pattern.

[0085]

In the display medium according to claim 21, in addition to the function of the display medium according to claim 19, the first medium and the second medium are mutually insoluble solvents, or solutions containing mutually insoluble solvents. Thus, phase separation of the first medium and the second medium can occur more easily.

[0086]

In the display medium as claimed in claim 22, in addition to the effect of the display medium as claimed in claim 21, one of the first medium and the second medium is water or an aqueous solution, and the other is water-insoluble A solvent or a solution containing the solvent. Thus, the first medium and the second medium can be phase-separated more easily, and a medium using water or an aqueous solution is easier to obtain.

[0087]

In the display medium as claimed in claim 23, in addition to the effect of the display medium as claimed in claim 22, the water is distilled water or deionized water, which is advantageous when the electrophoretic medium must have insulation, thereby improving the display. The quality of the medium.

[0088]

In the display medium as claimed in claim 24, in addition to the effect of the display medium as claimed in claim 22, the water-insoluble solvent is an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, silicone oil, or high-purity petroleum , or a mixture of two or more of the above. This composition is advantageous when the electrophoretic medium must have insulating properties, thereby improving the quality of the display medium.

[0089]

In the display medium according to claim 25, the charged particles in the display medium according to claim 19 include first particles whose surfaces have a greater affinity for the first medium than for the second medium, and the second Two particles, the surface of which has a greater affinity for the second medium than for the first medium, thereby facilitating the selective dispersion of the first particle and the second particle in the first medium and the second medium, respectively. In addition, since it is difficult for the first particles or the second particles dispersed in one medium to migrate into the other medium, it is possible to prevent the first particles from entering the second medium and prevent the second particles from entering the first medium, thereby maintaining a stable image quality.

[0090]

In the display medium according to claim 26, in addition to the function of the display medium according to claim 25, the first particles and the second particles have different colors. Therefore, if both the first medium and the second medium are transparent, color display can be realized by the colors of the first particles and the second particles. Since the colors of the first particles and the second particles function as color filters in this case, excellent brightness and color can be obtained to maintain high-quality images even in electrophoretic reflection type display media.

[0091]

In the display medium as claimed in claim 27, in addition to the effect of the display medium as claimed in claim 19, the first medium and the second medium have different colors, so the colors of the first medium and the second medium can realize Display in color. Therefore, a color display medium can be obtained relatively easily. In addition, since the colors of the first medium and the second medium function as color filters in this case, excellent brightness and color can be obtained to maintain high-quality images even in electrophoretic reflection type display media.

[0092]

In the display medium as claimed in claim 28, in addition to the effect of the display medium as claimed in claim 19, the electrode pairs are respectively arranged on the opposite surfaces of the substrate pair, and the protective film with flow resistance is arranged on each electrode. On the opposite side. This structure prevents direct contact between the liquid electrophoretic medium and the electrodes, thereby preventing the electrodes from deteriorating.

[0093]

In the display medium according to claim 29, in addition to the effect of the display medium according to claim 28, the protective film has a fluorine-containing compound. Thus, the composition can more effectively prevent direct contact between the electrophoretic medium and the electrode, thereby more effectively preventing deterioration of the electrode.

[0094]

In the display medium as claimed in claim 30, in addition to the effect of the display medium as claimed in claim 19, the pair of substrates is flexible, so that the entire display medium is flexible.

[0095]

In the display medium according to claim 31, in addition to the function of the display medium according to claim 19, the spacer maintains at least a predetermined distance between the pair of substrates. Thus, the structure can more reliably prevent excessive deformation in the substrate when a force is applied to its surface, thereby reliably preventing the substrate from being damaged. Since this structure prevents the substrates from coming into contact with each other due to internal slack when the substrates are bent, the structure can more reliably prevent deterioration of image quality and damage to the display medium.

[0096]

In the display medium according to claim 32, in addition to the function of the display medium according to claim 19, one of the pair of electrodes includes a first electrode and a second electrode which are alternately arranged in isolation from each other, and the first medium is provided at At positions corresponding to the first electrodes, the second medium is provided at positions corresponding to the second electrodes to form a predetermined pattern. A pixel may then be formed from adjacent regions in the first medium and the second medium. Therefore, when the color of the first medium (first color) and the color of the second medium (second color) are different or when the color of the first medium and the color of the second medium are the same but the charged particles contained in these mediums When the colors are different, the display medium can display a color image.

[0097]

In the display medium according to claim 33, in addition to the effect of the display medium according to claim 32, the first surface treatment portion having an affinity for the first medium greater than that for the second medium is provided on the first surface. On the electrode, a second surface treatment moiety having a greater affinity for the second medium than for the first medium is provided on the second electrode. Thus, by providing the first medium and the second medium on the surface of the electrode on which the first surface treatment part and the second surface treatment part are respectively provided, the structure can facilitate selective Configure the first medium and the second medium. Therefore, the first medium and the second medium can be arranged relatively easily at positions corresponding to the electrodes (the first electrode and the second electrode).

[0098]

The electrophoretic display according to claim 34, comprising an electric field control unit capable of independently controlling an electric field generated between the first electrode and an electrode opposite to the first electrode, and between the second electrode and an electrode opposite to the second electrode. generated electric field. Thus, the electrophoretic display enables the same behavior (response) of the charged particles contained in the medium provided at positions corresponding to the respective first and second electrodes when displaying or erasing images, even if The same is true when the media (the first medium and the second medium) are different, thereby achieving high-quality display.

[0099]

In the electrophoretic display according to claim 35, in addition to the function of the electrophoretic display according to claim 34, the electric field control unit independently controls the electric field by applying voltages of different driving waveforms to the first electrode or the second electrode. Thus, the electrophoretic display enables the same behavior (response) of the charged particles contained in the medium provided at positions corresponding to the respective first and second electrodes when displaying or erasing images, even if The same is true when the media (the first medium and the second medium) are different, thereby achieving high-quality display.

[0100]

A method of manufacturing a display medium as claimed in claim 36 is a method of manufacturing a display medium comprising an electrophoretic medium containing charged particles and provided between a pair of substrates spaced apart from each other and substantially parallel to each other, by means of the pair of substrates The electric field generated between them causes the charged particles contained in the electrophoretic medium to migrate, thereby switching the display state. In order to manufacture such display media, the manufacturing method includes a media layout process for arranging a mixture of an electrophoretic medium and a separation medium having fluidity at least at room temperature and separating from the electrophoretic medium on at least one of the pair of substrates The face of a substrate on the side opposite to another substrate. Then, by causing phase separation between the electrophoretic medium and the separation medium in the mixture provided on the surface of at least one substrate of the pair of substrates in the medium layout process, the separation medium as a spacer is provided in the space for separating the electrophoretic medium. position.

[0101]

Then, in the method of manufacturing a display medium as claimed in claim 36, the partition member for partitioning the electrophoretic medium is formed of a fluid substance. Therefore, when the entire display medium is bent, the spacer is not damaged when the display medium is bent.

[0102]

In addition, since the separator is formed by phase separation of the electrophoretic medium and the separation medium, the display medium can be manufactured more easily without complicated processes, thereby reducing production costs.

[0103]

In addition, since the separator is formed by phase separation of the electrophoretic medium and the separation medium, this method can more uniformly arrange the electrophoretic medium (including charged particles) as compared with the arrangement of the electrophoretic medium (including charged particles) after forming the separator. Thus, a display medium capable of suppressing uneven color and having a high contrast ratio can be obtained.

[0104]

In the method of manufacturing a display medium as claimed in claim 37, in addition to the effects of the method of manufacturing a display medium as claimed in claim 36, a surface treatment process for providing an affinity for the electrophoretic medium greater than A first surface treatment portion having an affinity for the separation medium is provided on a surface of at least one substrate of the pair of substrates on the side opposite to the other substrate at a position for disposing the electrophoretic medium, and provides a separation medium. A second surface treatment portion having a greater affinity for the medium than for the electrophoretic medium is provided on a face of at least one of the pair of substrates on a side opposite to the other substrate in accordance with the shape of the separation medium. Accordingly, the electrophoretic medium and the separation medium can be selectively arranged more easily at positions where the first surface treatment portion and the second surface treatment portion are provided.

[0105]

In the display medium produced by the method as claimed in claim 38, in addition to the effect of the method for producing a display medium as claimed in claim 36, the affinity of the charged particles to the electrophoretic medium is greater than the affinity to the separation medium, so that Charged particles can be selectively dispersed in the electrophoretic medium. In addition, charged particles dispersed in the electrophoretic medium can be suppressed from migrating to the separation medium forming the spacer and through the spacer to other regions of the electrophoretic medium, thereby preventing occurrence of uneven color and decrease in contrast, thus maintaining stable image quality.

[0106]

In the display medium produced by the method as claimed in claim 39, in addition to the effect of the method for producing a display medium as claimed in claim 36, before treating the surface with the surface treatment process, by coating with a liquid containing a fluorine-containing compound The surface of the electrode pair is covered, and a protective film with flow resistance is formed on the surface of the electrode pair. This method more effectively prevents direct contact between the liquid electrophoretic medium and the electrodes, thereby more effectively preventing electrode degradation.

[0107]

A method of manufacturing a display medium as claimed in claim 40 is a method of manufacturing the display medium comprising an electrophoretic medium containing charged particles and provided between a pair of substrates spaced apart from each other and substantially parallel to each other, by means of the pair of substrates The electric field generated between them causes the charged particles contained in the electrophoretic medium to migrate, thereby switching the display state. To manufacture such a display medium, the manufacturing method includes a medium layout process for disposing an electrophoretic medium including a first medium exhibiting a first color and a second medium exhibiting a second color. The second medium, which is provided on the side of at least one substrate of the substrate pair opposite to the other substrate, is capable of phase separation from the first medium at least at room temperature. Therefore, when the media are separated from each other in the medium separation process, the first medium and the second medium in the electrophoretic medium provided in the medium layout process form a prescribed pattern. Thus, in the display medium manufactured according to the method, the electrophoretic medium includes a first medium exhibiting a first color and a second medium exhibiting a second color capable of phase separation from the first medium at least at room temperature, and the prescribed pattern is A medium and a second medium are formed when they are in a phase-separated state from each other. Specifically, in the display medium produced by the production method according to claim 40, the electrophoretic medium between the substrates is formed into a predetermined pattern with the first medium and the second medium at least at room temperature.

[0108]

Therefore, when the color of the first medium (first color) and the color of the second medium (second color) are different or when the color of the first medium and the color of the second medium are the same but the color of the charged particles contained in the medium At the same time, a color display can be formed on the display medium by arranging a predetermined pattern capable of forming each pixel by using adjacent regions of the first medium and the second medium. Since the first medium and the second medium constituting the electrophoretic medium in this case can phase-separate at least at room temperature, a display medium capable of displaying a color image can be obtained relatively easily. In addition, in such color display media, the colors of the first and second media function as color filters to obtain excellent brightness and color, thereby maintaining high-quality images, even in electrophoretic reflective display media in this way.

[0109]

In the method of manufacturing a display medium as claimed in claim 41, in addition to the effects of the method of manufacturing a display medium as claimed in claim 40, one electrode of the pair of electrodes respectively provided on the opposite faces of the pair of substrates includes The first electrodes and the second electrodes arranged alternately are separated from each other, and a surface treatment process is performed so that a first surface treatment portion having a higher affinity for the first medium than for the second medium is provided on the surface of the first electrodes , and a second surface treatment portion having an affinity for the second medium greater than that for the first medium is provided on the surface of the second electrode. Therefore, by selectively disposing the electrophoretic medium to form a predetermined pattern, when the first medium and the second medium are phase-separated in the medium separation step, the first medium is provided at a position corresponding to the first electrode, and the second medium is placed at a position corresponding to the first electrode. The second medium is arranged at a position corresponding to the second electrode. For yes, pixels may be formed from adjacent regions in the first medium and the second medium. Therefore, when the color of the first medium (first color) and the color of the second medium (second color) are different or when the color of the first medium and the color of the second medium are the same but the charged particles contained in these mediums When the colors are different, the display medium can display a color image. This method also facilitates the manufacture of display media because the electrophoretic media can be selectively configured based on the first surface treatment and the second surface treatment.

[0110]

In the method of manufacturing a display medium as claimed in claim 42, in addition to the effects of the method of manufacturing a display medium as claimed in claim 41, before treating the surfaces of the first electrode and the second electrode with a surface treatment process, further A protective film forming process is performed, which forms a protective film having flow resistance on the surfaces of the electrode pairs by coating the surfaces of the electrode pairs with a liquid containing a fluorine-containing compound, thereby more effectively preventing the gap between the liquid electrophoretic medium and the electrodes. Direct contact occurs, preventing electrode deterioration more effectively.

[0111]

In the method of manufacturing a display medium as set forth in claim 43, in addition to the effects of the method of manufacturing a display medium as set forth in claim 40, the charged particles include an affinity for the first medium greater than that for the second medium and second particles having a greater affinity for the second medium than for the first medium, thereby facilitating selective dispersion of the first particles and the second particles in the first medium and the second medium, respectively. In addition, since it is difficult for the first particles or the second particles dispersed in one medium to migrate into the other medium, it is possible to prevent the first particles from entering the second medium and prevent the second particles from entering the first medium, thereby obtaining a stable image quality display media.

Description of drawings

[0112]

Figure 1(a) illustrates a problem in flexible display media when the display media with solid spacers is in an unbent state.

Figure 1(b) illustrates a problem in flexible display media when the display media with solid spacers is in a bent state.

Fig. 2(a) is a perspective view of a display for displaying images on a display medium according to a first embodiment of the present invention.

Fig. 2(b) is an exploded sectional perspective view showing the general structure of the display medium according to the first embodiment.

FIG. 3 is a schematic cross-sectional view of a display medium.

Fig. 4(a) shows the first embodiment in the surface treatment process before the formation of the first surface treatment layer.

Fig. 4(b) shows the first embodiment in the surface treatment process, showing the first substrate when the first surface treatment layer is provided on the protective film.

FIG. 4( c ) shows the first embodiment in the surface treatment process, and a metal mask is provided at this time.

Fig. 4(d) shows the first embodiment in the surface treatment process, in which infrared laser light is irradiated.

Fig. 4(e) shows the first embodiment in the surface treatment process, at this time the second surface treatment layer has been formed.

Fig. 5(a) shows a second embodiment in the surface treatment process before the layered body for ablation is formed.

Fig. 5(b) shows the second embodiment in the surface treatment process, showing the first substrate when the layered body for ablation is provided on the protective film.

FIG. 5( c ) shows the second embodiment in the surface treatment process, in which a metal mask is provided.

Fig. 5(d) shows a second embodiment in the surface treatment process, in which infrared laser light is irradiated.

FIG. 5( e ) shows the second embodiment in the surface treatment process, where the second surface treatment layer has been exposed.

Figure 6 shows the preparation of the mixture of electrophoretic medium and separation medium containing charged particles.

FIG. 7(a) shows a process of forming a spacer using a spacer medium, showing the substrate after the surface treatment process.

FIG. 7( b ) shows a process of forming a spacer using a spacer medium, showing a process of layout of the medium.

FIG. 7(c) shows a process of forming a spacer using a spacer medium, showing a spacer layout process.

FIG. 8 is a schematic cross-sectional view showing a display medium according to a second embodiment.

FIG. 9 is a schematic cross-sectional view showing a display medium according to a third embodiment.

FIG. 10 is a schematic sectional view showing a display medium according to a fourth embodiment.

Fig. 11(a) shows the first embodiment in the surface treatment process before the formation of the first surface treatment layer.

Figure 11(b) shows the first embodiment in the surface treatment process, showing the first substrate when the first surface treatment layer is provided on the protective film.

FIG. 11( c ) shows the first embodiment in the surface treatment process, and a metal mask is provided at this time.

Fig. 11(d) shows the first embodiment in the surface treatment process, in which infrared laser light is irradiated.

Fig. 11(e) shows the first embodiment in the surface treatment process, at this time the second surface treatment layer has been formed.

Fig. 12(a) shows a second embodiment in the surface treatment process before the layered body for ablation is formed.

Fig. 12(b) shows the second embodiment in the surface treatment process, showing the first substrate when the layered body for ablation is provided on the protective film.

Fig. 12(c) shows the second embodiment in the surface treatment process, in which a metal mask is provided.

Fig. 12(d) shows a second embodiment in the surface treatment process, in which infrared laser light is irradiated.

Fig. 12(e) shows the second embodiment in the surface treatment process, where the second surface treatment layer has been exposed.

Figure 13 shows the preparation process of the electrophoretic medium containing charged particles.

Fig. 14(a) shows the medium layout process, so that the electrophoretic medium containing charged particles is arranged between the substrates of the display medium.

Fig. 14(b) shows the medium layout process, in which the electrophoretic medium containing charged particles is arranged between the substrates of the display medium.

FIG. 15 is a block diagram showing electronic equipment for a display for displaying images on a display medium according to a fourth embodiment.

Explanation of labels

10 display media

12 first substrate (substrate)

12aX electrode (electrode)

13 second substrate (substrate)

13aY electrode (electrode)

18 protective film

19a First surface treatment layer (first surface treatment part)

19b second surface treatment layer (second surface treatment part)

30 electrophoresis medium

31 charged particles

31a white charged particles (charged particles)

31b black charged particles (charged particles)

32 separate media

34 spacer particles

14 fixed dividers

Detailed ways

[0114]

Next, preferred embodiments of the present invention will be described with reference to the drawings. 2(a) and 2(b) show a display medium 10 according to a first embodiment of the present invention. FIG. 2( a ) shows a perspective view of a display 1 for displaying images on a display medium 10 . FIG. 2(b) is an exploded sectional perspective view showing the general structure of the medium 10. As shown in FIG.

[0115]

As shown in FIG. 2( a ), the display 1 is composed of a display medium 10 and a main body 20 . After the display medium 10 is put in the main body 20, an image can be displayed on the display medium 10 by performing a predetermined operation.

[0116]

The main body 20 includes a bottom plate 25 having a rectangular shape and a size slightly larger than the display medium 10 , and a frame 26 installed along the peripheral edge of the bottom plate 25 . The opening is provided in the frame 26 in a section along the periphery of the bottom plate 25 (the left side of the bottom plate 25 in FIG. 2( a )). By providing this open section in the frame 26 , the user can insert the display medium 10 into the display 1 and withdraw the display medium 10 therefrom more easily. The frame 26 has a built-in drive control unit (not shown) for controlling electrical signals (current, voltage, and polarity).

[0117]

A power switch 26 a and operation buttons 26 b are provided on the surface of the frame 26 . A CPU (not shown) including a drive control unit (not shown) controls the power switch 26a. When the CPU detects that the power switch 26a has been turned on, the CPU supplies power to the main body 20 . The user operates the operation button 26 b to display an image on the display medium 10 .

[0118]

When the display medium 10 is inserted into a predetermined position on the base plate 25 in the display 1, the X electrodes 12a and the Y electrodes 13a (see FIG. 2(b)) in the display medium 10 are connected to the drive control unit (not shown) in the frame 26. )superior. At this time, by operating the operation button 26b, the user can display a desired image on the display medium 10 by controlling the drive control unit (not shown).

[0119]

As shown in Figure 2 (b), the display medium 10 mainly includes a first substrate 12, a second substrate 13, and a gap spacer 17 between the first substrate 12 and the second substrate 13, thereby forming Layered structure. The gap between the first substrate 12 and the second substrate 13 separated by the gap spacer 17 is filled with an electrophoretic medium 30 (see FIG. 3 ) containing charged particles 31 and a separation medium 32 (see FIG. 3 ) as a separator. , this structure will be described in more detail with reference to FIG. 3 .

[0120]

The first substrate 12 and the second substrate 13 each have a thickness of about 20 [mu]m and are formed of a material such as glass, synthetic resin, natural resin, or paper. The first substrate 12 and the second substrate 13 are preferably made of flexible synthetic resin materials, such as polyethylene terephthalate (PEP), polyethylene naphthalate (PEN), polyphenelzine sulfide (PPS) , or another polyester resin, etc.; aramid; polyimide; nylon; polypropylene; or rigid polyethylene (high-density polyethylene). Among these synthetic resins, polyethylene terephthalate, polyethylene naphthalate, and polyphenelzine sulfide are particularly preferred in terms of their strength, transparency, and heat resistance, and polyethylene terephthalate is most preferred. Ethylene formate. By using one of these flexible materials for the first substrate 12 and the second substrate 13, the entire display medium 10 can be made flexible.

[0121]

The X electrodes 12a and the Y electrodes 13a are provided on the surfaces of the first substrate 12 and the second substrate 13 in the display medium 10 facing each other, respectively. The X electrodes 12a and the Y electrodes 13a have electric polarity so as to apply an electric field to the electrophoretic medium 30 (see FIG. 3). The X electrodes 12a and the Y electrodes 13a include a plurality of linear electrodes substantially parallel to each other. The X electrodes 12a in the display medium 10 are disposed substantially perpendicular to the Y electrodes 13a. Thus, the display medium 10 displays images according to a simple matrix driving system in which the X electrodes 12a and Y electrodes 13a are turned on or off.

[0122]

The materials of the X electrodes 12 a and the Y electrodes 13 a are not particularly limited, as long as the materials have conductivity, such as metal, semiconductor, conductive resin, conductive coating, or conductive ink. Using one of these materials, according to one of various methods well known in the art, such as electroless plating, sputtering, vapor deposition, or inkjet methods, can be respectively deposited on the first substrate 12 and the second substrate 12. On the substrate 13, X electrodes 12a and Y electrodes 13a are formed. When the first substrate 12 and the second substrate 13 are formed of flexible synthetic resin, it is particularly easy to form the X electrode 12a and the Y electrode according to the inkjet method using ink containing a conductive polymer such as a conductive polythiophene polymer. 13a without damaging the substrates (first substrate 12 and second substrate 13).

[0123]

The gap spacer 17 is formed of one of synthetic resin, natural resin, or glass, for example, the above-mentioned proposals for the materials of the first substrate 12 and the second substrate 13 . The gap spacer 17 was formed to have an opening in the central region with a thickness of about 20 μm.

[0124]

A protective film 18 (see FIG. 3 ) having flow resistance and a surface treatment portion 19 (see FIG. 3 ) are provided on the surfaces of the X electrode 12 a and the Y electrode 13 a formed on the first substrate 12 and the second substrate 13, respectively. superior. To simplify the drawing of FIG. 2(b), the protective film 18 and the surface treatment portion 19 have been omitted.

[0125]

Next, the structure of the display medium 10 will be described in detail with reference to FIG. 3 . FIG. 3 is a schematic cross-sectional view of the display medium 10 . The section in FIG. 3 passes through one of the Y electrodes 13a formed on the second substrate 13 and passes through one of the X electrodes 12a formed on the first substrate 12 substantially orthogonal thereto.

[0126]

As shown in FIG. 3 , the region of the display medium 10 between the first substrate 12 and the second substrate 13 is filled with an electrophoretic medium 30 and a separation medium 32 . The electrophoretic medium 30 contains positively or negatively charged particles 31 . The separation medium 32 functions as a separator to separate the electrophoretic medium 30 .

[0127]

The electrophoretic medium 30 is arranged in the region corresponding to the pixel, and the partition medium 32 is arranged along the separation line so that the region corresponding to each pixel is separated from adjacent pixels, thereby drawing each pixel. A "pixel" in the display medium 10 corresponds to an area centered on an intersecting area of the X electrodes 12a and the Y electrodes 13a (arranged in a dot matrix), wherein one side of the X electrodes 12a and the Y electrodes 13a independent of other areas The electric field generated in the intersection region results in the migration of charged particles 31 in this region independently of charged particles 31 in other regions.

[0128]

Electrophoretic medium 30 and separation medium 32 are phase-separated from each other when medium 10 is operated at least at room temperature and are formed of a liquid or other fluid substance (solvent or solution) capable of maintaining this phase-separated state. When the phase separation of the electrophoretic medium 30 and the separation medium 32 occurs, it is preferable that the two liquids are completely separated at the interface. However, a "nearly phase-separated" state in which two liquids mix in the interface region is allowed as long as the liquids appear to be completely separated at the interface. Therefore, the term "phase separation" in the scope of the present specification and claims includes an approximate phase separation state and is not limited to a complete separation state at the interface of a liquid.

[0129]

Electrophoretic medium 30 and separation medium 32 are preferably a mixture of mutually insoluble solvents, a mixture of solutions comprising mutually insoluble solvents, or a mixture of mutually insoluble solvents and a solution comprising mutually insoluble solvents. Since the electrophoretic medium 30 is particularly preferably a liquid having a high electrical resistance (high insulation), the electrophoretic medium 30 is a water-insoluble solvent or a solution containing a water-insoluble solvent. The separation medium 32 is preferably water or an aqueous solution.

[0130]

When using a water-insoluble solvent as the electrophoretic medium 30, the solvent preferably has high resistance (high insulation) such as aromatic hydrocarbon solvents (such as benzene, toluene, and xylene), aliphatic hydrocarbon solvents (such as normal or cyclic Paraffinic solvents such as n-hexane or cyclohexane, isoparaffinic solvents, or kerosene), halogenated hydrocarbon solvents (such as chloroform, trichloroethylene, methylene chloride, trichlorotrifluoroethylene, or bromoethane), oily Polysiloxanes such as silicone oil, or high-purity petroleum. For the second medium 30b, aliphatic hydrocarbon solvents are especially preferred. Some examples of suitable second media 30b are Isopar G, H, M, and L (all manufactured by ExxonMobil Chemical), Shellsol (manufactured by Showa Shell Sekiyu), and IP Solvents 1016, 1620, 2028, 2835 (all manufactured by Idemitsu Sekiyu Made in Kagaku). The term "water-insoluble solvent" in the scope of the present specification and claims includes any one of the above-mentioned organic solvents and a mixture of two or more of the above-mentioned organic solvents.

[0131]

When the electrophoretic medium 30 is water or an aqueous solution, it is preferable to use water that has a high electrical resistance (high insulation) and does not contain ionic materials, and it is particularly preferable to use distilled water or ion-exchanged water.

[0132]

As noted above, separation medium 32 is a fluid substance capable of phase separating from electrophoretic medium 30 at least at room temperature. When using a water-insoluble solvent as the electrophoretic medium 30, from an accessibility point of view, the preferred water or aqueous solution for the separation medium 32, and when using water or an aqueous solution as the electrophoretic medium 30, the preferred water-insoluble solvent or aqueous solution for the separation medium 32 A solution containing a solvent that is insoluble in water. In this case, the water-insoluble solvent used as the separation medium 32 is preferably one of the above-mentioned solvents used as the electrophoretic medium 30 .

[0133]

Partition medium 32 acts as a partition wall to define pixels in display medium 10 . Therefore, the formed display medium 10 in the preferred embodiment uses the fluid material as the partition wall. Therefore, when the display medium 10 is bent, the separator does not break.

[0134]

Separation medium 32 is preferably colorless or white, so as not to adversely affect the image displayed by display medium 10 .

[0135]

The charged particles 31 (dispersed) contained in the electrophoretic medium 30 include positively charged white charged particles 31 a and negatively charged black charged particles 31 b. To form individual pixels in the display medium 10, white charged particles 31a and black charged particles 31b migrate toward the first substrate 12 side or the second substrate 13 side according to the electric field generated between the X electrode 12a and the Y electrode 13a.

[0136]

More specifically, when a positive electric field is generated on the second substrate 13 with respect to the X electrode 12a at the determined pixel place, the negatively charged black charged particles 31b move toward the second substrate 13 side (Y electrode 13a side) migration, the white charged particles 31a migrate toward the first substrate 12 side (X electrode 12a side). In this case, if the second substrate 13 is the surface on the user's viewing side (hereinafter referred to as "viewing surface"), the pixel appears black to the user. In the following description, when a user observes a pixel as black, the state of the pixel is referred to as a "display state".

[0137]

On the other hand, when generating a negative electric field relative to the X electrode 12a on the Y electrode 13a, the positively charged white charged particles 31a migrate to the second substrate 13 side (Y electrode 13a side), and the negatively charged black particles 31a migrate. The particles 31b migrate toward the first substrate 12 side (X electrode 12a side). In this case, if the second substrate 13 is the viewing surface, the user observes that the pixel is white. In the following description, the state when the user observes that the pixel appears white through the viewing surface is referred to as a "non-display state".

[0138]

The surfaces of the charged particles 31 (white charged particles 31 a and black charged particles 31 b ) have a greater affinity for the electrophoretic medium 30 than for the separation medium 32 . Accordingly, the charged particles 31 are selectively dispersed in the electrophoretic medium 30 rather than in the separation medium 32 . By providing charged particles 31 having such a surface, charged particles 31 dispersed in electrophoretic medium 30 can be prevented from migrating into partition medium 32 and via partition medium 32 to electrophoretic medium 30 in other regions. Therefore, this structure prevents color unevenness or a decrease in contrast from occurring in the display medium 10, thereby maintaining stable image quality.

[0139]

Examples of the white charged particles 31a and the black charged particles 31b include pigments (such as white titanium dioxide and black carbon black) coated with polymers or polymer particles dyed with white and black dyes.

[0140]

When the electrophoretic medium 30 is a water-insoluble solvent or a solution containing a water-insoluble solvent and the separation medium 32 is water or an aqueous solution, the charged particles 31 can display hydrophobic (lipophilic) polymers such as having hydrophobic surfaces on their surfaces. polymer manufacturing. Polymers having a hydrophobic surface include styrene resins, acrylic resins, styrene-acrylic copolymers, and polyester resins. Specific examples include Natoco-spacer (manufactured by Natoco), EPOCOLOR (manufactured by Shokubai, Japan), Chemisnow (manufactured by Soken Chemical & Engineering), Tospearl (manufactured by GE Toshiba Silicones), and Techpolymer (manufactured by Sekisui Plastics).

[0141]

If the electrophoretic medium 30 is water or an aqueous solution and the separation medium 32 is a water-insoluble solvent or a solution containing a water-insoluble solvent, a polymer having a hydrophobic surface is used as the charged particles 31 . In this case, the charged particle 31 having a hydrophilic surface can be obtained by forming a particle having a hydrophobic The polymer of the surface then deposits microparticles of a hydrophilic substance such as titanium dioxide or silica or forms a thin film of the hydrophilic substance on the surface of the charged particle comprising the dye or pigment. In addition, the charged particles 31 can also be made of a polymer having a hydrophilic surface. Some examples of polymers having a hydrophilic surface include particles obtained by dispersion polymerization of methyl methacrylate on the surface of polymer particles using a mixture of acrylamide and methylol acrylate or Copolymers obtained by polymerization of polyoxyethylene macromonomers as dispersion stabilizers, and particles obtained by graft polymerization of hydrophilic acrylate monomers or hydrophilic methacrylate monomers.

[0142]

As shown in FIG. 3 , protective films 18 are provided on the surfaces of the X electrodes 12 a and the Y electrodes 13 a in the display medium 10 . Since the protective film 18 prevents direct contact between the liquid electrophoretic medium 30 and the electrodes (X electrode 12a and Y electrode 13a), deterioration of the electrodes (X electrode 12a and Y electrode 13a) can be prevented. The protective film 18 is preferably a thin film of a fluorine-containing compound because fluorine-containing compounds have excellent hydrophobicity, oil resistance, corrosion resistance, and chemical resistance.

[0143]

The selected fluorine-containing compound should be liquid above the predetermined temperature, such as low molecular weight polytetrafluoroethylene (low molecular weight PTFE), low molecular weight polytrifluorochloroethylene (low molecular weight PCTFE), low molecular weight tetrafluoroethylene Ethylene-perfluoroalkyl vinyl ether copolymer (low molecular weight PFA), and low molecular weight tetrafluoroethylene-hexafluoropropylene copolymer (low molecular weight FEP).

[0144]

The protective film 18 is formed according to a process (hereinafter referred to as "protective film forming process") in which the above-mentioned fluorine-containing compound is heated to at least a predetermined temperature to convert the compound into a liquid state, and then uniformly coated thereon On the surface of the substrate (first substrate 12 or second substrate 13) provided with electrodes (X electrode 12a or Y electrode 13a), it is finally dried.

[0145]

In the protective film forming process, the fluorine-containing compound can be applied to the substrate (the first substrate 12 or the second substrate 13) using, for example, a dip coating method, a sol-gel method, or a spray coating method. The fluorine-containing compound used to form the protective film 18 may also be a compound that achieves coating by dissolving or dispersing in a solvent. In this case, the same protective film forming process as described above can also be carried out using a liquid having a dissolved or dispersed fluorine-containing compound.

[0146]

As shown in FIG. 3 , the surface treatment portion 19 is provided on the first substrate 12 serving as a viewing surface, and is a layer in contact with the electrophoretic medium 30 and the separation medium 32 . The surface treatment part 19 includes a first surface treatment layer 19a and a second surface treatment layer 19b.

[0147]

As shown in FIG. 3 , the exposed areas of the first surface treatment layer 19 a and the second surface treatment layer 19 b correspond to the positions where the electrophoretic medium 30 and the separation medium 32 are disposed. The second surface treatment layer 19b is provided in the region corresponding to the pixels, and the first surface treatment layer 19a is provided at the position where the spacer for defining the pixels will be formed, which will be referred to FIG. 7(a)-FIG. 7 (c) for a more detailed description.

[0148]

The second surface treatment layer 19b is a layer such that at least its surface has a greater affinity for the electrophoretic medium 30 than the separation medium 32, while the first surface treatment layer 19a is a layer such that at least its surface has a greater affinity for the separation medium. The affinity for 32 is greater than the affinity for 30 for the electrophoretic medium. For example, if the electrophoretic medium 30 is a water-insoluble solvent or a solution containing the solvent, and the separation medium 32 is water or an aqueous solution, the surface of the second surface treatment layer 19b exhibits hydrophobicity (or lipophilicity), and the first surface treatment layer 19b exhibits hydrophobicity (or lipophilicity). The surface of layer 19a exhibits hydrophilicity.

[0149]

Thus, when the electrophoretic medium 30 and the separation medium 32 are phase-separated, by disposing the electrophoretic medium 30, its affinity for the second surface treatment layer 19b is greater than that for the separation medium 32 and is in contact with the second surface treatment layer 19b. , and the separation medium 32, whose affinity to the first surface treatment layer 19a is greater than that to the electrophoretic medium 30 and is in contact with the first surface treatment layer 19a, can obtain the most stable energy state. Therefore, the second surface treatment layer 19b and the first surface treatment layer 19a are provided so that the electrophoretic medium 30 and the separation medium 32 in a phase-separated state in contact with the second surface treatment layer 19b and the first surface treatment layer 19a are selectively configured. get simplified.

[0150]

The surface treatment portion 19 (the first surface treatment layer 19a and the second surface treatment layer 19b) is preferably provided on the side of the first substrate 12 which is the viewing surface. By providing the first surface treatment layer 19a and the second surface treatment layer 19b on the first substrate 12 side, the pixel area formed by the electrophoretic medium 30 and the partition formed by the partition medium 32 can be clearly defined. The surface treatment portion 19 should be transparent when it is provided on the first substrate 12 side so as not to affect the display.

[0151]

In addition, even if the electrophoretic medium 30 and the separation medium 32 arranged at a predetermined position between the first substrate 12 and the second substrate 13 are in a phase-separated state due to external factors such as when pressure is applied to the first substrate 12 and the When mixing occurs on the second substrate 13, the electrophoretic medium 30 and the separation medium 32 can then also return to the respective second surface treatment layer 19b or first surface treatment layer 19a.

[0152]

Next, a method of forming the surface treatment portion 19 (hereinafter referred to as "surface treatment process") will be described with reference to FIGS. 4(a)-4(e) and FIGS. 5(a)-5(e). Figure 4(a)-Figure 4(e) shows the first embodiment of the surface treatment process, and Figure 4(a)-Figure 4(e) shows the second embodiment of the surface treatment process.

[0153]

The first embodiment shown in Figure 4(a)-Figure 4(e) is a surface treatment process using a hydrophilic polymer that can be selectively converted to hydrophobic in areas exposed to infrared laser light Sexual (hereinafter referred to as thermosensitive phase transition hydrophilic polymer). This method is well known in the art and commonly used in the printing industry (for example, in the SFPlateless DOP technology developed by Creo).

[0154]

FIG. 4(a) shows the state of the substrate after the protective film forming process and before the first surface treatment layer 19a is formed. FIG. 4( b ) shows the first substrate 12 , where the first surface treatment layer 19 a is provided on the protective film 18 . A heat-sensitive phase change hydrophilic polymer is coated on the protective film 18 by spraying or the like, thereby forming the first surface treatment layer 19a.

[0155]

4(c)-4(e) show how to form the second surface treatment layer 19b by irradiating infrared laser light. As shown in FIG. 4(c), once the first surface treatment layer 19a is provided on the protective film 18, the metal mask 40 is provided on the first surface treatment layer 19a. The metal mask 40 has a plurality of openings 40a disposed at the positions of the pixels and corresponding in shape to the pixels (for example, approximately polygonal, such as rectangular or hexagonal). The metal mask 40 is set so that the opening 40a is at the expected position for forming the second surface treatment layer 19b, that is, the position corresponding to the pixel.

[0156]

Next, as shown in FIG. 4( d ), the infrared laser is irradiated onto the first surface treatment layer 19 a through the metal mask 40 in the direction of the arrow. As shown in FIG. 4( e ), a part of the first surface treatment layer 19 a exposed to the infrared laser light passing through the opening 40 a phase-transforms into the hydrophobic second surface treatment layer 19 b. As described above, the openings 40a in the metal mask 40 are formed at positions corresponding to the pixels. Then, by infrared laser exposure, the second surface treatment layer 19b is formed in the region corresponding to the pixel on the X electrode 12a, while the first surface treatment layer 19a remains at the position where the spacer is provided to separate the pixel.

[0157]

The second embodiment shown in FIGS. 5(a)-5(e) is a surface treatment process in which the hydrophilic surface layer is removed by exposing the underlying hydrophobic layer by irradiation of infrared laser light. This method is also well known in the art and commonly used in the printing industry (eg REALwet developed by Presstek).

[0158]

Fig. 5(a) shows the state of the substrate after the protective film forming process and before the layered body for ablation is provided. FIG. 5(b) shows the first substrate 12, and the layered body for ablation is provided on the protective film 18 at this time. The layered body for ablation has three layers including a first surface treatment layer 19a formed of a hydrophilic polymer, a second surface treatment layer 19b formed of a hydrophobic film, and The metal release layer 16 between the second surface treatment layer 19b. As shown in FIG. 5(b), a layered body for ablation is provided on top of the protective film 18 together with the second surface treatment layer 19b.

[0159]

5(c)-5(e) show how the surface treatment portion 19 is formed by irradiation of infrared laser light. As shown in FIG. 5(c), once the layered body for ablation is provided on the protective film 18, the metal mask 40 is provided on the first surface treatment layer 19a and has a plurality of pixels corresponding to the positions of the pixels. The opening 40 a corresponds to and has a shape corresponding to the pixel (for example, a polygonal shape such as an approximately rectangular shape or an approximately hexagonal shape). At this time, the metal mask 40 is set so that the opening 40a is set at the expected position for forming the second surface treatment layer 19b, that is, the position corresponding to the pixel.

[0160]

Next, as shown in FIG. 5( d ), infrared laser light is irradiated onto the layered body for ablation through the metal mask 40 in the direction of the arrow. As shown in Figure 5 (e), the first surface treatment layer 19a and the part in the metal peeling layer 16 in the layered body exposed by the irradiation of the infrared laser through the opening 40a are ablated, thereby exposing the hydrophobicity. The second surface treatment layer 19b. As described above, the openings 40a in the metal mask 40 are provided at positions corresponding to the pixels. Then, when exposed with an infrared laser, the second surface treatment layer 19b is formed in the region of the X electrode 12a corresponding to the pixel, while the first surface treatment layer 19a remains there to provide a spacer to delimit the pixel boundary. position.

[0161]

According to the method shown in FIGS. 4(a)-4(e) or 5(a)-5(e) as described above, by changing the shape and position, the patterns (shape and layout) of the first surface treatment layer 19a and the second surface treatment layer 19b can be changed more easily. Thus, the shape and size of the partitions of the electrophoretic medium 30 formed of the partition medium 32 can be freely changed.

[0162]

The method of providing the surface treatment portion 19 is not limited to the method described above. Various methods can be used to form the surface treatment portion 19 . For example, a polymer having an affinity for the electrophoretic medium 30 greater than that for the separation medium 32 can be coated on a position corresponding to a pixel using a roller or the like, and a polymer having an affinity for the separation medium 32 greater than that for the electrophoretic medium A 30-affinity polymer is coated where the spacers are used to define the pixels. In addition, a polymer having an affinity for the electrophoretic medium 30 greater than that for the separation medium 32 may be sprayed on the entire first substrate 12, and then a polymer having an affinity for the separation medium 32 greater than that for the electrophoretic medium 30 may be sprayed with a roller or the like. Affinity polymers are applied in locations where spacers are positioned to define pixels.

[0163]

Next, a method of disposing the electrophoretic medium 30 and the separation medium 32 on the display medium 10 will be described with reference to FIGS. 6 and 7(a)-7(c). FIG. 6 shows the preparation process of the mixture of electrophoretic medium 30 and separation medium 32 containing charged particles 31 . 7(a)-7(c) illustrate the process of forming a spacer using a spacer medium 32. Referring to FIG.

[0164]

In order to prepare the mixture of the electrophoretic medium 30 and the separation medium 32 according to the preferred embodiment, first by dispersing in the electrophoretic medium 30 charged particles 31 (white charged particles 31 a and black charged particles 31b) to prepare a dispersion liquid (hereinafter this dispersion liquid will be referred to as "electrophoretic liquid D"). Next, the electrophoretic liquid D is mixed with the separation medium 32 and fully stirred to prepare an emulsion (hereinafter referred to as “emulsion E”) as shown in the bottom diagram of FIG. 6 , wherein the separation medium 32 is dispersed in the electrophoretic medium 30 .

[0165]

In the following description referring to FIGS. Although the emulsion E shown in FIG. 6 is an emulsion in which the separation medium 32 is dispersed in the electrophoretic medium 30, the emulsion E may also be an emulsion in which the electrophoretic medium 30 is dispersed in the separation medium 32.

[0166]

As shown in Figure 7 (b), after carrying out the surface treatment process, the emulsion E prepared as described above is coated on the first substrate 12 on which the gap spacer 17 is laminated with the scraper coating method (hereinafter referred to as "Media Layout Process"). In FIG. 7( b ), the charged particles 31 dispersed in the emulsion E and the gap spacers 17 laminated on the first substrate 12 have been omitted for simplification of drawing.

[0167]

After performing the medium layout process, as shown in FIG. 7(c), the emulsion E coated on the first substrate 12 is automatically separated to form a separation medium 32 (hereinafter referred to as "separation element") as a spacer at a predetermined position. Component Layout Process"). In the spacer layout process, based on the affinity of the surface treatment portion 19 formed on the first substrate 12 in the surface treatment process ( FIG. 32) Selectively arrange. Specifically, through the phase separation emulsion E, the electrophoretic medium 30 is selectively disposed on the second surface treatment layer 19b, and the affinity of this layer to the electrophoretic medium 30 is greater than that to the separation medium 32, and the separation medium 32 selects is selectively provided on the first surface treatment layer 19a, which has a greater affinity for the separation medium 32 than for the electrophoretic medium 30.

[0168]

When the emulsion E phase separates into the electrophoretic medium 30 and the separation medium 32 , the charged particles 31 whose surfaces have a greater affinity for the electrophoretic medium 30 than for the separation medium 32 become selectively dispersed in the electrophoretic medium 30 .

[0169]

After the medium layout process is completed, the display medium 10 is prepared by placing the second substrate 13 on the gap spacer 17 and sealing its periphery without introducing air bubbles.

[0170]

The dielectric layout process shown in FIG. 7(b) is an example of a method for coating the emulsion E on one substrate (the first substrate 12) of the pair of substrates. However, another method is to inject the emulsion E into a pre-assembled tank formed by the first substrate 12, the gap spacer 17, and the second substrate 13 using a feeder or the like. According to this spacer layout process, the emulsion E injected into the grooves selectively forms spacers (separation medium 32) on the first surface treatment layer 19a according to the pattern of the surface treatment portion 19 formed on the first substrate 12. .

[0171]

Therefore, the method of the preferred embodiment is to use the electrophoretic medium 30 and the separation medium 32 that automatically phase separate and selectively arrange the electrophoretic medium 30 and the separation medium 32 according to the difference in their affinity for the first surface treatment layer 19a or the second surface treatment layer 19b. Separation medium 32 . Therefore, the method simplifies the production process of the display medium 10 while avoiding a complicated process to form the solid spacer and solving the problem of difficulty in injecting the electrophoretic medium after the solid spacer is formed.

[0172]

In the display medium 10 of the first embodiment as described above, the electrophoretic medium 30 and the separation medium 32 are capable of phase separation at least at room temperature. In this phase-separated state, electrophoretic medium 30 is separated by the region occupied by separation medium 32 . Thus, the partition medium 32 of the fluid substance functions as a partition. Therefore, damage to the separator is suppressed when the flexible display medium 10 is bent. In addition, since the separator is formed by phase separation of the electrophoretic medium 30 and the separation medium 32, the display medium 10 can be manufactured with a simple method.

[0173]

In this case, the second surface treatment layer 19b having an affinity for the electrophoretic medium 30 greater than that for the separation medium 32 is provided on the surface of the first substrate 12 in contact with the electrophoretic medium 30 at the position where the electrophoretic medium 30 is disposed. Above, the first surface treatment layer 19a having a higher affinity for the separation medium 32 than for the electrophoretic medium 30 is provided on the surface of the first substrate 12 in contact with the separation medium 32 according to the shape corresponding to the spacer. Thus, the electrophoretic medium 30 and the separation medium 32 are selectively arranged at positions where the second surface treatment layer 19b and the first surface treatment layer 19a are provided.

[0174]

In addition, since the surface of the charged particles 31 has a greater affinity for the electrophoretic medium 30 than for the separation medium 32, the charged particles 31 dispersed in the region of the electrophoretic medium 30 separated by the separation medium 32 are inhibited from moving toward the separation medium. 32 and migrate through the separation medium 32 to other regions of the electrophoretic medium 30. Thus, uneven color development and a decrease in contrast can be prevented from occurring in the display medium 10, thereby maintaining stable image quality.

[0175]

Next, the display medium 10 according to the second embodiment will be described with reference to FIG. 8 , in which the same parts and components are denoted by the same reference numerals to avoid repeated description.

[0176]

In the display medium 10 of the first embodiment, the partition is formed only with the partition medium 32 which is a liquid material. However, as shown in FIG. 8 , the partition in the display medium 10 according to the second embodiment is formed of a partition medium 32 containing spacer particles 34 .

[0177]

The presence of the spacer particles 34 maintains at least a predetermined distance between the pair of substrates (the first substrate 12 and the second substrate 13 ) in the display medium 10 . Since such a configuration can reliably prevent excessive deformation in the surface of the first substrate 12 or the second substrate 13 when a force is applied thereto, it is possible to reliably prevent the first substrate 12 or the second substrate 13 from being damaged. destroy. This configuration is particularly effective in preventing the first substrate 12 and the second substrate 13 from coming into contact with each other due to the slack of the substrates when the first substrate 12 and the second substrate 13 are bent, thereby more reliably preventing deterioration of image quality. Poor and the display medium is damaged.

[0178]

The spacer particles 34 are formed of an inorganic material such as glass or a polymer material with a predetermined diameter. Preferably, the surface of the spacer particles 34 has a greater affinity for the separation medium 32 than for the electrophoretic medium 30 or has been treated to exhibit such an affinity. For example, the spacer particle 34 is preferably obtained by depositing one of the hydrophilic substances exemplified in the description of the charged particle 31 on the surface of the polymer particle or coating the polymer particle with the hydrophilic substance. Using the spacer particles 34 whose surfaces have a higher affinity for the separation medium 32 than for the electrophoretic medium 30 facilitates the selective arrangement of the spacer particles 34 in the separation medium 32 .

[0179]

Next, a display medium 10 according to a third embodiment will be described with reference to FIG. 9 , in which the same parts and components are denoted by the same reference numerals to avoid repeated description.

[0180]

As shown in FIG. 9 , a display medium 10 according to the third embodiment has a fixed partition 14 whose one end is fixed to a first substrate 12 and separated from a second substrate 13 . According to a method well known in the art using a photosensitive resin and a photomask, a fixed spacer 14 is formed on the first substrate 12 by fixing a sheet-like body formed of glass, resin, or the like to the first substrate. The sheet 12 is constructed on top of the sheet 12, which is smaller than the distance between the first substrate 12 and the second substrate 13 and has a through hole (approximately rectangular, hexagonal, or other polygonal shape) corresponding to the shape of the pixel. Since the fixed spacer clearly partitions the electrophoretic medium 30, it is preferable that the fixed spacer 14 is fixed to the side of the first substrate 12 which is the viewing surface.

[0181]

When the fixed spacer 14 can keep at least a predetermined distance between the electrode pair (the first substrate 12 and the second substrate 13), the fixed spacer 14 is separated from the second substrate 13, thereby reducing the pressure on the flexible display medium 10. Probability of damage to the separator during bending.

[0182]

In addition, as shown in FIG. 9 , the space between the fixed spacer 14 and the second substrate 13 is filled with a spacer medium 32 . The separation medium 32 prevents the charged particles 31 dispersed in one region of the electrophoretic medium 30 from migrating to other regions of the electrophoretic medium 30 . Therefore, although the conventional fixed spacer with both ends fixed to the substrate plays the same role, the fixed spacer 14 and the second substrate 13 are separated from each other as described above, so that the flexible display medium 10 is lowered when the flexible display medium 10 is bent. The probability that the divider will be damaged.

[0183]

As shown in FIG. 9, the second surface treatment layer 19b in the display medium 10 of the third embodiment is provided on the second substrate 13 separated from the fixed spacer 14 at a position corresponding to the X electrodes 12a. A surface treatment layer 19a is provided on the second substrate 13 at a position corresponding to the opposite face of the fixed spacer 14 . The first surface treatment layer 19 a and the second surface treatment layer 19 b can selectively dispose the separation medium 32 in the gap between the fixed spacer 14 and the second substrate 13 .

[0184]

As shown in FIG. 9, when the surface treatment part 19 is provided on the second substrate 13 side, it is preferable to use a feeder or the like to inject the emulsion E into the first substrate 12, the gap spacer 17, and the second substrate. The method in the pre-assembled groove formed by the substrate 13 is used to complete the dielectric layout process. Here, the separation between the fixed spacer 14 and the second substrate 13 facilitates the injection of the emulsion E, so that the electrophoretic liquid D is uniformly arranged in each pixel.

[0185]

Although the case where the surface treatment part 19 is not provided on the second substrate 13 side is not shown in the figure, the second surface treatment layer 19b may be provided on the first substrate 12 at a position corresponding to the X electrode 12a. On the protective film 18, and on the surface of the fixed spacer 14 opposite to the second substrate 13, the first surface treatment layer 19a is provided. In this case, the second surface treatment layer 19b can be formed according to one of the methods described above, such as a method using a heat-sensitive phase-transition hydrophilic polymer or coating with a roller or the like having an affinity for the electrophoretic medium 30 greater than To the method of the polymer of the affinity of separation medium 32, the first surface treatment layer 19a can be coated with the solution of the polymer (such as polyvinyl alcohol solution, polyvinyl alcohol solution, At this time, the separation medium 32 is formed by water or an aqueous solution).

[0186]

Next, the display medium 10 according to the fourth embodiment will be described with reference to FIG. 2 and FIGS. 10 to 15 , and the same parts and components in the figures are marked with the same reference numerals to avoid repeated description. [0187]

The display medium 10 according to the fourth embodiment is similar to the display medium 10 of the first embodiment shown in the general perspective view and the exploded view of FIG. 2 . Unlike the description of the first embodiment, the X electrodes 12 a and the Y electrodes 13 a may be formed of a transparent inorganic conductor, and the gap spacers 17 may be formed of a ceramic material.

[0188]

As shown in FIG. 10, the X electrodes 12a are composed of a plurality of alternately arranged linear XA electrodes 12a1 and XB electrodes 12a2. The XA electrode 12a1 and the XB electrode 12a2 form an electrode pair opposing the Y electrode 13a for generating an electric field between the first substrate 12 and the second substrate 13 . The control unit 70 (see FIG. 15 ) provided in the main body 20 controls to apply voltages of different driving waveforms to the XA electrode 12a1 and the XB electrode 12a2, so that between the XA electrode 12a1 and the Y electrode 13a and between the XB electrode A different electric field is generated between 12a2 and the Y electrode 13a, which will be described in more detail with reference to FIG. 15 .

[0189]

As described below, different types of media (first media 30a and second media 30b constituting electrophoretic media 30) are provided at positions corresponding to XA electrodes 12a1 and XB electrodes 12a2, respectively. Thus, by generating different electric fields between the XA electrode 12a1 and the Y electrode 13a and between the XB electrode 12a2 and the Y electrode 13a, it is possible to make the charged particles dispersed in different media (the first medium 30a and the second medium 30b) (White charged particles 31 a and black charged particles 31 b constituting charged particles 31 ) produce the same behavior (response).

[0190]

As shown in FIG. 10 , the gap between the first substrate 12 and the second substrate 13 in the display medium 10 is filled with an electrophoretic medium 30 containing positively or negatively charged particles 31 . The electrophoretic medium 30 is composed of a first medium 30a and a second medium 30b in a phase-separated state. As shown in FIG. 10 , the first dielectric 30 a and the second dielectric 30 b form a line centered on each of the plurality of linear X electrodes 12 a. The first medium 30a and the second medium 30b are arranged alternately (striped). More specifically, the first medium 30a is provided at a position corresponding to the XA electrode 12a1, and the second medium 30b is provided at a position corresponding to the XB electrode 12a2.

[0191]

The first medium 30a and the second medium 30b constituting the electrophoretic medium 30 are liquids (solvents or solutions) that are phase-separated from each other at least at room temperature (the temperature at which the medium 10 is operated) and can maintain the phase-separated state. When phase separation occurs between the first medium 30a and the second medium 30b, it is preferred that the two liquids are completely separated at the interface. However, a "nearly phase-separated" state in which two liquids mix in the interface region is tolerated as long as the liquids are approximately completely separated at the interface.

[0192]

The first medium 30a and the second medium 30b are preferably a mixture of mutually insoluble solvents, a mixture of solutions comprising mutually insoluble solvents, or a mixture of mutually insoluble solvents and a solution comprising mutually insoluble solvents. In this composition, the first medium 30a is preferably water or an aqueous solution, and the second medium 30b is preferably a water-insoluble solvent or a solution containing a water-insoluble solvent.

[0193]

When water or an aqueous solution is used as the first medium 30a, it is preferred to use water with high electrical resistance (high insulation) and no ionic material, especially distilled water or ion-exchanged water.

[0194]

When using a water-insoluble solvent as the second medium 30b, the preferred solvent has high resistance (high insulation) such as aromatic hydrocarbon solvents (such as benzene, toluene, and xylene), aliphatic hydrocarbon solvents (such as normal or cyclic Paraffin solvents such as n-hexane or cyclohexane, isoparaffin solvents, or kerosene), halogenated hydrocarbon solvents (such as chloroform, trichloroethylene, dichloromethane, trichlorotrifluoroethylene, or bromoethane), Oily polysiloxanes such as silicone oil, or high-purity petroleum. For the second medium 30b, aliphatic hydrocarbon solvents are especially preferred. Some examples of suitable second media 30b are Isopar G, H, M, and L (all manufactured by ExxonMobil Chemical), Shellsol (manufactured by Showa Shell Sekiyu), and IP Solvents 1016, 1620, 2028, 2835 (all manufactured by Idemitsu Sekiyu manufactured by Kagak-u). The term "water-insoluble solvent" in the scope of the specification and claims of the present invention includes any one of the above-mentioned organic solvents and a mixture of two or more of the above-mentioned organic solvents.

[0195]

In a preferred embodiment, the first medium 30a and the second medium 30b have different colors (eg, red and blue). Colored first medium 30a and second medium 30b can be prepared by dissolving suitable pigments that are soluble in first medium 30a and second medium 30b.

[0196]

When the charged particles 31 (white charged particles 31a) dispersed in the first medium 30a migrate to the surface side opposite to the surface visible to the user (hereinafter referred to as "viewing surface"), the user observes the color of the first medium 30a (for example, blue). Likewise, when the charged particles 31 (black charged particles 31b ) dispersed in the second medium 30b migrate to the side opposite to the view plane, the user observes the color (for example, red) of the second medium 30b. In the following description, it is assumed that the user views the display medium 10 from the direction indicated by the arrow V. As shown in FIG. In other words, the first substrate 12 will be the viewing surface.

[0197]

Thus, the colors in the first medium 30a and the second medium 30b in the display medium 10 function as color filters, thereby enabling the display medium 10 of the preferred embodiment to display colors. In addition, since a color display can be obtained using the colors of the first medium 30a and the second medium 30b, compared with a display provided with a separate color filter on the viewing surface side, even an electrophoretic type reflective display medium can achieve Higher brightness display with more vivid colors.

[0198]

The charged particles 31 are composed of first particles 31a dispersed in a first medium 30a and second particles 31b dispersed in a second medium 30b, both of which are positively (or negatively) charged and are white or pale colored.

[0199]

The surface of the second particle 31b has a greater affinity for the second medium 30b than for the first medium 30a. Thus, the second particles 31b are selectively dispersed in the second medium 30b without being dispersed in the first medium 30a. Since the second particles 31b selectively dispersed in the second medium 30b are difficult to mix into the first medium 30a, the probability of generating a bias voltage in the charged particles 31 dispersed in the electrophoretic medium 30 is reduced, thereby maintaining a stable image quality.

[0200]

When the first medium 30a is water or an aqueous solution and the second medium 30b is a water-insoluble solvent or a solution containing a water-insoluble solvent, the second particle 31b may be such that its surface exhibits hydrophobicity (lipophilicity) rather than hydrophilicity. Non-destructive polymer particles, such as polymer particles composed of polymers with hydrophobic surfaces. Specific examples of the polymer having a hydrophobic surface include those mentioned in the first embodiment.

[0201]

On the other hand, the surface of the first particle 31a has a greater affinity for the first medium 30a than for the second medium 30b. Thus, the second particles 31a are selectively dispersed in the first medium 30a without being dispersed in the second medium 30b. Since the first particles 31a selectively dispersed in the first medium 30a are hardly mixed into the second medium 30b, almost no bias voltage is generated in the charged particles 31 dispersed in the electrophoretic medium 30, thereby maintaining stable image quality.

[0202]

If the first medium 30a is water or an aqueous solution and the second medium 30b is a water-insoluble solvent or a solution containing a water-insoluble solvent, a polymer having a hydrophilic surface rather than a hydrophobic surface is used as the first particle 31a. For example, the second particles 31b can be formed by depositing fine particles of a hydrophilic substance, such as titanium dioxide or silica, or forming a thin film of the hydrophilic substance on the surface of a resin having a hydrophobic surface or a hydrophobic surface exemplified above. A polymer particle composed of a polymer with a hydrophilic surface. Specific examples of the polymer having a hydrophilic surface include those mentioned in the first embodiment.

[0203]

The first particles 31a and the second particles 31b migrate toward the first substrate 12 side or the second substrate 13 side by an electric field generated between the X electrode 12a (XA electrode 12a1 and XB electrode 12a2) and the Y electrode 13a. Here, a region in which the first particles 31a and the second particles 31b independently migrate by virtue of the electric field generated between the single intersecting X electrodes 12a and Y electrodes 13a arranged in a lattice form is referred to as "the smallest particle." Migration Zone".

[0204]

More specifically, when the electric field formed in a minimum particle migration region makes the potential of the X electrode 12a positive with respect to the potential of the Y electrode 13a, the positively charged particles 31 (the first particles 31a or the second particles 31b ) migrates to the second substrate 13 side (the Y electrode 13a side). In this case, the user observes the color of the second substrate 13 provided in this minimum particle migration area. Specifically, if the electrophoretic medium 30 provided in the minimum particle migration region (in which the charged particles 31 migrate toward the second substrate 13 side) is the blue first medium 30a, the user observes blue. However, if the electrophoretic medium 30 within this region of minimal particle migration is the red second medium 30b, the user observes red. In a preferred embodiment, when the user observes the color of the electrophoretic medium 30 from the side of the viewing surface, the state of the smallest particle migration region is called a "display state".

[0205]

However, when the electric field generated in a minimum particle migration region makes the potential of the X electrode 12a negative with respect to the potential of the Y electrode 13a, the positively charged particles 31 (the first particles 31a or the second particles 31b) move toward the second particle. A substrate 12 side (X electrode 12a side) migrates. In this case, the user observes white or light-colored charged particles 31 . Here, when the user observes white from the viewing surface side, the state of the smallest particle migration region is referred to as "non-display state".

[0206]

The opposite is true when the charged particles 31 are negatively charged. Specifically, when the electric field generated in this region makes the X electrode 12a positive relative to the Y electrode 13a, the minimum particle migration region is in a non-display state, and when the electric field generated in this region makes the X electrode 12a positive relative to the Y electrode. When 13a is negative, the minimum particle migration area is in the displayed state.

[0207]

As described above, the colored first medium 30 a and second medium 30 b function as color filters in the display medium 10 . Thus, if the groups of adjacent minimum particle migration regions used in the first medium 30a and the second medium 30b constitute a single pixel, then by controlling the migration energy of the charged particles 31 (the first particles 31a and the second particles 31b) The color difference components of two colors in one pixel, thereby realizing the color display on the display medium 10. Here, a single pixel may include at least one of the minimum particle migration regions used in the first medium 30a and the second medium 30b or a plurality of these minimum particle migration regions

[0208]

As shown in FIG. 10, a protective film 18 is provided on the surfaces of the X electrode 12a and the Y electrode 13a. Since the protective film 18 prevents direct contact between the liquid electrophoretic medium 30 and the electrodes (X electrode 12a and Y electrode 13a), deterioration of the electrodes (X electrode 12a and Y electrode 13a) can be prevented. The protective film 18 is preferably a thin film having a fluorine-containing compound because of its excellent hydrophobicity, oil repellency, corrosion resistance, and chemical resistance.

[0209]

Here, for example, the fluorine-containing compound may be one of the materials described in the first embodiment. For example, the method of forming the protective film 18 may be one of the methods described in the first embodiment.

[0210]

As shown in FIG. 10, a surface treatment portion 19 is provided on the first substrate 12 serving as a viewing surface, and is a layer in contact with the electrophoretic medium 30. As shown in FIG. The surface treatment part 19 includes a first surface treatment layer 19a and a second surface treatment layer 19b.

[0211]

As shown in FIG. 10, the exposure areas of the first surface treatment layer 19a and the second surface treatment layer 19b correspond to positions where the first medium 30a and the second medium 30b are to be disposed. Although not shown in the drawing, the exposed regions of the first surface treatment layer 19a and the second surface treatment layer 19b are formed in a stripe shape along the XA electrode 12a1 and the XB electrode 12a2 in a line shape, respectively.

[0212]

The first surface treatment layer 19a is a layer in which at least a surface in contact with the electrophoretic medium 30 has a greater affinity for the first medium 30a than for the second medium 30b, while the second surface The treatment layer 19b is a layer having at least one surface in contact with the electrophoretic medium 30 that has a greater affinity for the second medium 30b than for the first medium 30a. For example, if the first medium 30a is water or an aqueous solution, and the second medium 30b is a water-insoluble solvent or a solution containing the solvent, then the first surface treatment layer 19a is a layer having a hydrophilic surface, and the second surface treatment layer 19a is a layer having a hydrophilic surface. Layer 19b is a layer having a hydrophobic (or lipophilic) surface.

[0213]

Thus, when the phase separation occurs between the first medium 30a and the second medium 30b, the first medium having an affinity for the first surface treatment layer 19a greater than that for the second medium 30b is provided on the first surface treatment layer 19a. 30a, and on the second surface treatment layer 19b, a second medium 30b whose affinity to the second surface treatment layer 19b is greater than that to the first medium 30a is provided to achieve the most stable energy state. Therefore, the first surface treatment layer 19a and the second surface treatment layer 19b are provided, which makes the first medium 30a and the second medium 30b in a phase-separated state on the first surface treatment layer 19a and the second surface treatment layer 19b respectively Selective settings are simplified. Furthermore, even if the first medium 30a and the second medium 30b arranged at a predetermined position between the first substrate 12 and the second substrate 13 are in a phase-separated state due to external factors such as when pressure is applied to the first substrate 12 and the second substrate 13), but the first medium 30a and the second medium 30b can also return to the respective first surface treatment layer 19a or second surface treatment layer 19b subsequently.

[0214]

Here, the surface-treated portion 19 (the first surface-treated layer 19a and the second surface-treated layer 19b) is preferably provided on the side of the first substrate 12 which is the viewing surface in the preferred embodiment. By providing the first surface treatment layer 19a and the second surface treatment layer 19b on the first substrate 12 side, the first medium 30a and the second medium 30b can be clearly defined. In addition, the surface treatment portion 19 should be transparent when provided on the first substrate 12 side so as not to affect the display.

[0215]

Next, a method for forming the surface treatment portion 19 (hereinafter referred to as "surface treatment process") will be described with reference to FIGS. 11(a)-11(e) and 12(a)-12(e). Figure 11(a)-Figure 11(e) shows the first embodiment of the surface treatment process, and Figure 12(a)-Figure 12(e) shows the second embodiment of the surface treatment process.

[0216]

The first embodiment shown in Figure 11(a)-Figure 11(e) is a surface treatment process using a hydrophilic polymer that can be selectively converted to hydrophobic in areas exposed to infrared laser light. Sexual (hereinafter referred to as "thermosensitive phase transition hydrophilic polymer"). This method is the same as the first example of the surface treatment process in the first embodiment.

[0217]

FIG. 11(a) shows the state of the substrate after performing the protective film forming process and before forming the first surface treatment layer 19a. FIG. 11( b ) shows the first substrate 12 with the first surface treatment layer 19 a provided on the protective film 18 at this time. The first surface treatment layer 19a is formed by coating the protective film 18 with a thermosensitive phase change hydrophilic polymer by spraying or the like.

[0218]

11(c)-11(e) show how to form the second surface treatment layer 19b by irradiating infrared laser light. As shown in FIG. 11(c), once the first surface treatment layer 19a is provided on the protective film 18, a metal masking template 40 is provided on the first surface treatment layer 19a. There are a plurality of approximately rectangular openings 40 a with a predetermined width in the metal mask 40 . The metal mask plate 40 is arranged so that the opening 40a is in a desired position for forming the second surface treatment layer 19b, and more specifically, the longitudinal direction of the opening 40a is substantially parallel to the XB electrode 12a2 and the width direction thereof is substantially parallel to the XB electrode 12a2. The width of 12a2 is centered.

[0219]

Next, as shown in FIG. 11( d ), the infrared laser is irradiated onto the first surface treatment layer 19 a through the metal mask 40 in the direction of the arrow. As shown in FIG. 11( e ), a hydrophobic second surface treatment layer 19 b is formed in a region of the first surface treatment layer 19 a exposed to the infrared laser beam through the metal mask 40 . As mentioned above, the longitudinal direction of the opening 40 a of the metal mask 40 is substantially parallel to the XB electrode 12 a 2 , and the width direction thereof is substantially centered on the XB electrode 12 a 2 . Then, when irradiated with infrared laser light, the surface of the surface-treated portion 19 formed is the first surface-treated layer 19a including the second surface-treated layer 19b (including a line of predetermined width centered on the XB electrode 12a2) and the exposed portion. (including lines of a predetermined width centered on the XA electrode 12a1) alternate stripes.

[0220]

The second embodiment shown in Fig. 12(a)-Fig. 12(e) is a surface treatment process in which the layered body for ablation is removed by exposing the underlying hydrophobic layer by irradiation with an infrared laser Hydrophilic surface layer in . This method is the same as the second example of the surface treatment process in the first embodiment.

[0221]

Fig. 12(a) shows the state of the substrate after performing the protective film forming process and before forming the layered body for ablation. FIG. 12(b) shows the first substrate 12, and the layered body for ablation is provided on the protective film 18 at this time. The layered body for ablation has three layers including a first surface treatment layer 19a formed of a hydrophilic polymer, a second surface treatment layer 19b formed of a hydrophobic film, and The metal release layer 16 between the second surface treatment layer 19b. As shown in FIG. 12( b ), the layered body for ablation is arranged so that the second surface treatment layer 19 b is on top of the protective film 18 .

[0222]

12(c)-12(e) show how the surface treatment portion 19 is formed by irradiation of infrared laser light. As shown in Figure 12 (c), once the layered body for ablation is provided on the protective film 18, the metal mask 40 is provided on the first surface treatment layer 19a and has a plurality of approximately rectangular shapes with predetermined width of the opening 40a. At this time, the metal mask 40 is set so that the opening 40a is provided at a desired position for forming the second surface treatment layer 19b. Specifically, the opening 40a is arranged such that its longitudinal direction is substantially parallel to the XB electrode 12a2, and its width direction is substantially centered on the width of the XB electrode 12a2.

[0223]

Next, as shown in FIG. 12( d ), infrared laser light is irradiated onto the layered body for ablation through the metal mask plate 40 in the direction of the arrow. As shown in Figure 12 (e), the first surface treatment layer 19a and the metal peeling layer 16 in the layered body exposed through the irradiation of the infrared laser through the opening 40a are partially ablated, thereby exposing the hydrophobic first layer. Two surface treatment layers 19b. As mentioned above, the opening 40 a of the metal mask 40 is arranged such that its longitudinal direction is substantially parallel to the XB electrode 12 a 2 , and its width direction is substantially centered on the XB electrode 12 a 2 . Then, when irradiated with infrared laser light, the surface (exposed surface) of the surface treatment portion 19 is formed in the form of the first surface treatment layer 19a (having a line of predetermined width centered on the XA electrode 12a1) and the exposed second surface treatment layer 19a. Alternating stripes of layer 19b (having a line of predetermined width centered on the XB electrode 12a2).

[0224]

According to the method shown in FIG. 11(a)-FIG. 11(e) or FIG. position, the patterns (shape and layout) of the first surface treatment layer 19a and the second surface treatment layer 19b can be changed more easily. For example, the approximately rectangular first surface treatment layer 19a and the second surface treatment layer 19b may be arranged in a checkerboard pattern.

[0225]

The method of providing the surface treatment portion 19 is not limited to the method described above. Various methods can be used to form the surface treatment portion 19 . For example, a polymer having a higher affinity to the first medium 30a than to the second medium 30b can be applied as a line centered on the XA electrode 12a1 using a roller or the like, while a roller or the like can be used to coat the polymer having an affinity to the second medium 30b. A polymer having an affinity greater than that for the first medium 30a is coated as a line centered on the XB electrode 12a2,

[0226]

Next, a method of disposing the electrophoretic medium 30 between the substrates (first substrate 12 and second substrate 13) of the display medium 10 will be described with reference to FIG. 13 and FIG. 14(a) and FIG. 14(b). FIG. 13 shows the preparation process of the electrophoretic medium 30 containing charged particles 31 . 14(a) and 14(b) show the process of disposing the electrophoretic medium 30 containing charged particles 31 between the substrates of the display medium 10 (the first substrate 12 and the second substrate 13).

[0227]

To prepare the electrophoretic medium 30 comprising charged particles 31 according to the preferred embodiment, the first process comprises preparing a first medium 30a having dispersed therein first particles 31a whose surface has an affinity for the first medium 30a greater than the affinity to the second medium 30b (hereinafter referred to as "dispersion liquid Da"), and the second medium 30b in which the second particles 31b are dispersed, and the surface of the second particle 31b is opposite to the second medium The affinity for 30b is greater than the affinity for the first medium 30a (hereinafter, this dispersion liquid is simply referred to as "dispersion liquid Db"). Next, as shown in the bottom diagram of FIG. 13, the dispersion liquids Da and Db are mixed and sufficiently stirred to form an emulsion in which the second medium 30b is dispersed in the first medium 30a.

[0228]

14(a) and 14(b), the electrophoretic medium 30 containing the charged particles 31 in an emulsified state as described above (hereinafter referred to as the emulsion of the electrophoretic medium 30 as "emulsion E") is set in the second between the first substrate 12 and the second substrate 13 . Although FIG. 13 shows an emulsion in which the second medium 30b is dispersed in the first medium 30a, an emulsion in which the first medium 30a is dispersed in the second medium 30b may also be used.

[0229]

As shown in FIG. 14( a ), the emulsion E prepared as described above is provided between the first substrate 12 and the second substrate 13 according to the dielectric layout process. The media layout process is performed by using a feeder or the like to inject the emulsion E from the injection hole (not shown) provided in the pre-assembled tank C (made by the first surface treatment part 19 including the surface treatment part 19 on the uppermost layer). The substrate 12, the gap spacer 17, and the protective film 18 at the bottom layer are formed).

[0230]

After the emulsion E is injected into the tank C in the media layout process, the injection hole (not shown) is sealed. Next, a media separation process as shown in FIG. 14(b) is performed. In the medium separation process, the emulsion E injected into the tank C spontaneously undergoes phase separation, so that the first medium 30a and the second medium 30b can be selectively placed at the corresponding positions of the XA electrode 12a1 and the XB electrode 12a2, respectively. position. More specifically, the first medium 30a and the second medium 30b are selectively disposed on the first surface treatment layer 19a and the second surface treatment layer 19b, respectively, by spontaneous phase separation of the emulsion E injected into the tank C. In addition, when the emulsion E phase-separates into the first medium 30a and the second medium 30b, the first particles 31a whose surface has a greater affinity for the first medium 30a than for the second medium 30b are selectively dispersed in the second medium 30a. In one medium 30a, second particles 31b whose surface has a higher affinity for the second medium 30b than for the first medium 30a are selectively dispersed in the second medium 30b.

[0231]

Thus, the method of the preferred embodiment uses a first medium 30a and a second medium 30b that phase-separate spontaneously and based on the difference between their affinity for the first surface treatment 19a and the second surface treatment 19b The first medium 30a and the second medium 30b are selectively provided. Thus, the method facilitates the manufacture of the display medium 10 according to the preferred embodiment.

[0232]

Next, a method of controlling image display on the display medium 10 having this structure will be described with reference to FIG. 15 . FIG. 15 is a block diagram showing the electronic structure of the display 1 for displaying images on the display medium 10 .

[0233]

The display 1 includes a display medium 10 having an XA electrode 12a1, an XB electrode 12a2, and a Y electrode 13a, and a main body 20. The main body 20 includes a control unit 70 to control image display on the display medium 10 . Control unit 70 comprises central processing unit (CPU) 71, ROM 72, RAM 73, storage unit 74, image interface 75 (image I/F 75), Y pulse voltage control circuit 76, in order to provide Y pulse voltage control circuit 76 Voltage Y drive source 77 , X pulse voltage control circuit 78 , and X drive source 79 for supplying voltage to X pulse voltage control circuit 78 .

[0234]

The ROM 72 is a non-rewritable memory for storing the control program executed by the CPU 71 and the data required for the CPU 71 to execute the control program. The control program stored in the ROM 72 controls voltages applied to the XA electrodes 12a1, XB electrodes 12a2, and Y electrodes 13a (forming prescribed lines) according to the image data stored in the RAM 73 and the memory unit 74.

[0235]

The RAM 73 is a non-permanent memory for temporarily storing data and programs required by the CPU 71 to perform various processes and for temporarily storing image data input from the outside via an interface (not shown). The storage unit 74 is a permanent memory such as a hard disk, and stores image data and the like input from the outside via an interface (not shown). The CPU 71 processes image data stored in the RAM 73 and the storage unit 74 and outputs the processed data to the image I/F 75.

[0236]

The function of the image I/F 75 is to perform various processes based on the image data input from the RAM 73 and the storage unit 74 through the CPU 71, such as a calibration process for calculating resistance and viscosity of the first medium 30a and the second medium 30b. The image I/F 75 also plays a role in outputting the processed data to the Y pulse voltage control circuit 76 and the X pulse voltage control circuit 78.

[0237]

The Y pulse voltage control circuit 76 converts the voltage supplied from the Y drive source 77 into a drive pulse corresponding to the signal received from the image I/F 75 and outputs the drive pulse to the Y electrode 13a.

[0238]

The X pulse voltage control circuit 78 converts the voltage supplied from the X drive source 79 into a drive pulse corresponding to the signal received from the image I/F 75 and outputs the drive pulse to the XA electrode 12a1 and the XB electrode 12a2. The calibration process performed by the image I/F 75 causes the X pulse voltage control circuit 78 to output different driving pulses to the XA electrode 12a1 and the XB electrode 12a2 based on the characteristics of the first medium 30a and the second medium 30b.

[0239]

The above-mentioned Y pulse voltage control circuit 76 and X pulse voltage control circuit 78 apply voltages to the Y electrode 13a, the XA electrode 12a1, and the XB electrode 12a2, so that the Y electrode 13a and the XA electrode 12a1 and XB electrode 12a2 in the display medium 10 An electric field is generated between the XB electrodes 12a2.

[0240]

The display medium 10 of the preferred embodiment uses two kinds of media, namely, a first medium 30 a and a second medium 30 b as the electrophoretic medium 30 . Since different media have different resistances and viscosities, when the same drive pulse is applied to the XA electrode 12a1 and the XB electrode 12a2, the first particle 31a in the first medium 30a and the second particle 31b in the second medium 30b The performance (response) is different.

[0241]

However, since the display 1 independently controls the voltages applied to the XA electrodes 12a1 and the XB electrodes 12a2, different driving pulses are output to the electrodes based on the characteristics of the first medium 30a and the second medium 30b, so that the Y electrodes 13a and the X The same electric field can be generated between electrodes 12a (XA electrode 12a1 and XB electrode 12a2 ) even when different media (first media 30a and second media 30b ) are used in display media 10 . Thus, the same behavior (response) can be generated between the first particle 31a and the second particle 31b, thereby ensuring high-quality display.

[0242]

As described above, the electrophoretic medium 30 in the display medium 10 of the fourth embodiment includes the first medium 30a exhibiting the first color and the second medium 30b exhibiting the second color and being separated from the first medium 30a at least at room temperature. Thus, the region of the first medium 30a and the region of the second medium 30b can be independently formed.

[0243]

In this case, by providing the first surface treatment layer 19a having an affinity for the first medium 30a greater than that for the second medium 30b on the surface in contact with the first medium 30a and the second medium 30b and the first surface treatment layer 19a having an affinity for the second medium 30b The second surface treatment layer 19b whose affinity for the medium 30b is greater than the affinity for the first medium 30a can easily selectively set the first medium 30a and the second medium 30b to take the XA electrode 12a1 and the XB electrode 12a2 as The center of the line shape, thereby forming alternate lines respectively centering on the XA electrode 12a1 and the XB electrode 12a2. Therefore, it is easier to manufacture the display medium 10 capable of displaying color images by a simple method.

[0244]

As described in the preferred embodiment, by selectively disposing the first medium 30a and the second medium 30b as a line centered on the XA electrode 12a1 and the XB electrode 12a2 by this method, color) and the second medium 30b (second color) using different colors, the display medium 10 capable of displaying a color image is manufactured by constituting a single pixel in an adjacent area in the first medium and the second medium. In addition, since the colors of the first medium 30a and the second medium 30b function as color filters in this case, bright and clear colors can be produced even for electrophoretic reflection type display media, thereby maintaining high-quality images .

[0245]

Display 1 of the fourth embodiment independently controls voltages applied to XA electrodes 12a1 and XB electrodes 12a2. Thus, when different media (the first medium 30a and the second medium 30b) are used in the display medium 10, different driving pulses can be output based on the characteristics of the first medium 30a and the second medium 30b, thereby generating a positive signal at the Y electrode 13a and the second medium 30b. The same electric field is generated between the X electrodes 12a (XA electrodes 12a1 and XB electrodes 12a2). Since this leads to the same behavior (response) in the first particle 31a and the second particle 31b, a high-quality image can be displayed.

[0246]

Next, the display medium 10 according to the fifth embodiment will be described, and the same parts and components in the drawings are denoted by the same reference numerals to avoid duplication of description.

[0247]

Although the display medium 10 according to the fourth embodiment realizes color display by using the first medium 30a and the second medium 30b having different colors, the display medium 10 according to the fifth embodiment realizes color display by using the first medium 30a and the second medium 30b of the same color. The second medium 30b uses first particles 31a and second particles 31b of different colors to realize color display.

[0248]

The structure of the display medium 10 according to the fifth embodiment is the same as the display in the fourth embodiment except that the first medium 30a and the second medium 30b of the same color are used and the first particles 31a and the second particle 31b of different colors are used. The structure of the medium is the same. In the fifth embodiment, the first medium 30a and the second medium 30b used in the display medium 10 are preferably white or light colored.

[0249]

In the display medium 10 according to the fifth embodiment, when the colored charged particles 31 (the first particles 31a and the second particles 31b) migrate toward the viewing surface (the first substrate 12 side), the user sees the charged particles 31 s color. Specifically, when the charged particles 31 (first particles 31a) dispersed in the first medium 30a migrate to the viewing surface side, the user observes the color (such as blue) of the first particles 31a, and when dispersed in the second When the charged particles 31 (second particles 31b ) in the medium 30b migrate to the side of the viewing surface, the user observes the color (such as red) of the second particles 31b.

[0250]

However, when the colored charged particles 31 (first particles 31a and second particles 31b) migrate to the side of the surface opposite to the viewing surface, the user observes the color (eg, white) of the first medium 30a or the second medium 30b. This state is the non-display state in the fifth embodiment.

[0251]

Then, as described in the fourth embodiment, using the structure as in the fifth embodiment (that is, using the first medium 30a and the second medium 30b of the same color but using the first particles contained in these mediums of different colors 31a and second particles 31b), a color image can be displayed on the display medium 10 by constituting a single pixel of adjacent regions in the first medium 30a and the second medium 30b.

[0252]

Since the display medium 10 according to the fifth embodiment can display a color image using the colors of the first particles 31a and the second particles 31b, compared with the case where a separate color filter is provided on the viewing surface side, the display medium 10 can display a color image. Higher brightness and clearer display are produced even when the display medium 10 is an electrophoretic reflection type display medium.

[0253]

As described in the fourth embodiment, the control unit 70 disposed in the main body 20 of the display 1 independently controls voltages applied to the XA electrodes 12a1 and the XB electrodes 12a2 in the display medium 10 according to the fifth embodiment. Thus, when different media (the first medium 30a and the second medium 30b) are used in the display medium 10, it is still possible to output different drive pulses based on the characteristics of the first medium 30a and the second medium 30b to generate a positive signal on the Y electrode. The same electric field is generated between 13a and X electrode 12a (XA electrode 12a1 and XB electrode 12a2). Thus, the same behavior (response) can be generated in the first particle 31a and the second particle 31b, thereby obtaining high-quality display.

[0254]

Although the present invention has been described in detail with specific implementations, those skilled in the art can make various improvements and changes without departing from the spirit of the present invention and the scope defined by the appended claims .

[0255]

For example, although the electrodes provided on the display medium 10 according to the preferred embodiment described above use a simple matrix drive system, the present invention is also applicable to an active matrix drive system in which voltages are directly applied to on the semiconductor switch.

[0256]

In addition, although the surface treatment portion 19 is provided on only one substrate (the first substrate 12) in the preferred embodiment, the surface treatment portion 19 may be provided on two substrates (the first substrate 12 and the second substrate 12). 13). In addition, the first surface treatment layer 19a and the second surface treatment layer 19b can be provided on different substrates, for example, the first surface treatment layer 19a is provided on the first substrate 12 and the second surface treatment layer 19b is provided on the second substrate. On the second substrate 13.

[0257]

Furthermore, although the surface treatment portion 19 is provided on the first substrate 12 as the viewing surface in the preferred embodiment, the surface treatment portion 19 may be provided on the second substrate 13 instead.

[0258]

In addition, the X electrodes 12a and the Y electrodes 13a may be omitted in the display medium 10 although they are provided on opposite surfaces of the first substrate 12 and the second substrate 13 in the preferred embodiment. In this case, an electrode pair corresponding to the X electrode 12a and the Y electrode 13a is provided on the main body 20 side, and by inserting the display medium 10 without the X electrode 12a or the Y electrode 13a between the electrode pairs provided on the main body 20 , the display 1 can be manufactured to display images.

[0259]

In the preferred embodiment as described above, the display medium 10 can be separated from the main body 20 in the display 1 . However, the display medium 10 and the main body 20 integrally constitute the display 1 .

[0260]

In addition, in the preferred embodiment, the first medium 30a which is water or an aqueous solution and the second medium 30b which is a water-insoluble solvent or a solution containing the solvent are described first. However, both the first medium 30a and the second medium 30b may be a water-insoluble solvent or a solution containing the solvent as long as the two media undergo phase separation at least at room temperature.

[0261]

In the first to third embodiments described above, the partition medium 32 forms a partition surrounding each pixel. However, the partition medium 32 may also constitute a partition surrounding a plurality of pixels.

[0262]

In addition, although the fixed partition 14 is provided so as to surround each pixel in the third embodiment, the fixed partition 14 may be provided instead of a part of the display medium 10 at a position not corresponding to the pixel. Displays the islands in the area. In this case, the partitions for defining pixels are formed by the fixed partitions 14 and the partition medium 32 filled in the gaps between the fixed partitions 14 .

[0263]

In the fourth and fifth embodiments described above, only the gap spacer 17 is interposed between the first substrate 12 and the second substrate 13 . However, particle spacers may be added between the first substrate 12 and the second substrate 13 when the tank C is assembled. The particle spacers present in the display medium 10 can maintain a predetermined distance or a greater distance between the first substrate 12 and the second substrate 13 .

[0264]

In the fourth and fifth embodiments, a spacer in contact with one substrate and separated from the other substrate or a spacer with a linking portion may be provided instead of the particle spacers.

[0265]

In addition, the medium layout process of the fourth and fifth embodiments described above includes injecting the emulsion E after assembling the tank C, and in another medium layout process, the first medium 30a and the second medium 30b can also be selectively are arranged on the positions corresponding to the XA electrode 12a1 and the XB electrode 12a2 respectively, and the process is to apply the emulsion E to the first substrate 12 having the surface treatment part 19 by using the doctor blade method and then in the dielectric separation process Emulsion E was achieved by spontaneous phase separation. In this case, when the emulsion E is applied in the dielectric layout process, the gap spacers 17 have been laminated on the first substrate 12 . After the medium layout process is completed, the display medium 10 is prepared by placing the second substrate 13 on the gap spacer 17 and sealing the periphery without introducing air bubbles.

[0266]

In the fourth and fifth embodiments as described above, the first particles 31a and the second particles 31b have the same color and the first medium 30a and the second medium 30b have different colors (fourth embodiment), or may Instead, the first particles 31a and the second particles 31b have different colors and the first medium 30a and the second medium 30b have the same color (fifth embodiment). However, it is also possible to have the first medium 30a and the second medium 30b have the same color and to have the first particles 31a and the second particles 31b also have the same color.

[0267]

In this case, the voltages applied to the XA electrodes 12a1 and the XB electrodes 12a2 are controlled independently by constituting a single pixel of adjacent regions in the first medium 30a and the second medium 30b and using the control unit 70 in the main body 20, thereby Get a high-resolution image display.

[0268]

Furthermore, in the fourth and fifth embodiments as described above, the first particles 31a and the second particles 31b each dispersed in the first medium 30a or the second medium 30b are composed of particles of a single color and are positively irradiated. charging or negative charging. However, these particles may consist of positively charged particles and negatively charged particles of a different color from the positively charged particles.

[0269]

Furthermore, in the fourth and fifth embodiments described above, the first medium 30a and the second medium 30b are arranged in a strip shape. However, the first medium 30a and the second medium 30b may also be configured in a checkerboard pattern, a honeycomb pattern, or the like. In this case, by arranging the first surface treatment layer 19a and the second surface treatment layer 19b in the same checkerboard pattern or honeycomb pattern, it is easier to arrange the first medium 30a and the second medium 30b in a predetermined shape. , such as a checkerboard or honeycomb pattern.

Industrial Applicability

[0270]

A display medium, an electrophoretic display, and a manufacturing method for manufacturing a display medium according to the present invention can be applied to a rewritable display medium.

Claims (43)

1. a display medium (10), it comprises:

Separate and be arranged in parallel pair of substrate (12,13); And

Be located at described substrate between (12,13) and comprise the electrophoretic medium (30) of charged particle (31), by at described substrate to (12,13) electric field that produces between, the charged particle (31) that is included in the described electrophoretic medium (30) is moved, thus the conversion show state

It is characterized in that, described display medium (10) also comprises the separation medium (32) that at least at room temperature has flowability and be separated with described electrophoretic medium (30), described separation medium (32) is in the attitude that is separated that is separated with described electrophoretic medium (30), described separation medium (32) be arranged on described substrate (12,13) between as separator to separate described electrophoretic medium (30).

2. display medium as claimed in claim 1 (10), it also comprises:

First surface processing section (19a), its to the affinity of described electrophoretic medium (30) greater than affinity to described separation medium (32); And

Second surface processing section (19b), its to the affinity of described separation medium (32) greater than affinity to described electrophoretic medium (30),

It is characterized in that, described second surface processing section (19b) is according to the shape of described separation medium (32), be located at described substrate to (12,13) at least one substrate in and the face that described separation medium (32) contacts, described first surface processing section (19a) is located at described substrate being used at least one substrate in (12,13) and the face that described electrophoretic medium (30) contacts is provided with on the position of described electrophoretic medium (30).

3. display medium as claimed in claim 2 (10) is characterized in that, described first surface processing section (19a) and second surface processing section (19b) are transparent and are arranged at the user and are considered as on the described substrate (12,13) of display surface.

4. display medium as claimed in claim 1 (10) is characterized in that, described electrophoretic medium (30) and described separation medium (32) are mutual insoluble solvents, or comprises the solution of mutual insoluble solvent.

5. display medium as claimed in claim 4 (10) is characterized in that, a kind of in described electrophoretic medium (30) and the described separation medium (32) is water or aqueous solution, and is another kind of then be water-immiscible solvent or the solution that comprises water-immiscible solvent.

6. display medium as claimed in claim 4 (10) is characterized in that, described separation medium (32) is water or aqueous solution, and described electrophoretic medium (30) is water-immiscible solvent or the solution that comprises water-immiscible solvent.

7. display medium as claimed in claim 4 (10) is characterized in that, described water-immiscible solvent is aromatic solvent, aliphatic hydrocarbon solvent, halogenated hydrocarbon solvent, silicone oil or high-purity petroleum or comprises above-mentioned two or more potpourri.

8. display medium as claimed in claim 1 (10) is characterized in that, described separation medium (32) is colourless or white.

9. display medium as claimed in claim 1 (10) is characterized in that, the surface of described charged particle (31) to the affinity of described electrophoretic medium (30) greater than affinity to described separation medium (32).

10. display medium as claimed in claim 1 (10), it also comprises:

A pair of be located at respectively described substrate to the electrode on the opposite face of (12,13) (12a, 13a); And

Have bleeding resistance and be located at each electrode (12a, the diaphragm on opposite face 13a) (18).

11. display medium as claimed in claim 10 (10) is characterized in that, described diaphragm (18) has fluorochemicals.

12. display medium as claimed in claim 1 (10) is characterized in that, described substrate all is flexible to (12,13).

13. display medium as claimed in claim 1 (10), it also comprises and is located at described substrate to (12,13) between so that described substrate to keeping the spacer particles (34) of preset distance between (12,13), described spacer particles (34) is contained in to be separated in the medium (32).

14. display medium as claimed in claim 13 (10) is characterized in that, the surface of described spacer particles (34) to the affinity of described separation medium (32) greater than affinity to described electrophoretic medium (30).

15. display medium as claimed in claim 1 (10), it also comprises and is located at described substrate between (12,13) and be fixed to the fixedly separator (14) of described substrate at least one on-chip bulk in (12,13).

16. display medium as claimed in claim 15 (10) is characterized in that, described fixedly separator (14) is fixed to described substrate to separating on the substrate in (12,13) and with another substrate (12,13).

17. display medium as claimed in claim 16 (10) is characterized in that, described separation medium (32) be located at described fixedly separator (14) and the substrate (12,13) that separates with described fixedly separator (14) between.

18. display medium as claimed in claim 16 (10), it is characterized in that, in the described fixedly separator (14) towards separated substrate (12,13) surface, perhaps the substrate (12,13) of this side of separating with described fixedly separator (14) with corresponding surface, above-mentioned surface to the affinity of described separation medium (32) greater than affinity to described electrophoretic medium (30).

19. a display medium (10) comprising:

Separate and be arranged in parallel pair of substrate (12,13);

Charged particle (31); And

Be located at described substrate between (12,13) and comprise the electrophoretic medium (30) of charged particle (31), by at described substrate to (12,13) electric field that produces between, the charged particle (31) that is included in the described electrophoretic medium (30) is moved, thus the conversion show state

It is characterized in that, described electrophoretic medium (30) comprises first medium (30a) that presents first color and second medium (30b) that presents second color, described second medium (30b) at least at room temperature can be separated with described first medium (30a), described second medium (30b) and described first medium (30a) are separated each other, to form predetermined pattern.

20. display medium as claimed in claim 19 (10), it also comprises:

First surface processing section (19a), its to the affinity of described first medium (30a) greater than affinity to described second medium (30b); And

Second surface processing section (19b), its to the affinity of described second medium (30b) greater than affinity to described first medium (30a),

It is characterized in that, described first surface processing section (19a) and described second surface processing section (19b) all according to the rules pattern be located at described substrate at least one substrate in (12,13) and the face that described electrophoretic medium (30) contacts.

21. display medium as claimed in claim 19 (10) is characterized in that, described first medium (30a) and described second medium (30b) are mutual insoluble solvents, or comprise the solution of mutual insoluble solvent.

22. display medium as claimed in claim 21 (10) is characterized in that, a kind of in described first medium (30a) and described second medium (30b) is water or aqueous solution, another kind of then be water-immiscible solvent or the solution that comprises water-immiscible solvent.

23. display medium as claimed in claim 22 (10) is characterized in that, described water is distilled water or deionized water.

24. display medium as claimed in claim 22 (10) is characterized in that, described water-immiscible solvent is aromatic solvent, aliphatic hydrocarbon solvent, halogenated hydrocarbon solvent, silicone oil or high-purity petroleum or comprises above-mentioned two or more potpourri.

25. display medium as claimed in claim 19 (10), it is characterized in that, described charged particle (31) comprises first particle (31a), its surface to the affinity of described first medium (30a) greater than affinity to described second medium (30b), with second particle (31b), its surface to the affinity of described second medium (30b) greater than affinity to described first medium (30a).

26. display medium as claimed in claim 25 (10) is characterized in that, described first particle (31a) has different colors with described second particle (31b).

27. display medium as claimed in claim 19 (10) is characterized in that, described first medium (30a) has different colors with described second medium (30b).

28. display medium as claimed in claim 19 (10), it also comprises:

A pair of be located at respectively described substrate to the electrode on the opposite face of (12,13) (12a, 13a); And

Have bleeding resistance and be located at each electrode (12a, the diaphragm on opposite face 13a) (18).

29. display medium as claimed in claim 28 (10) is characterized in that, described diaphragm (18) has fluorochemicals.

30. display medium as claimed in claim 19 (10) is characterized in that, described substrate all is flexible to (12,13).

31. display medium as claimed in claim 19 (10), it also comprises and is located at described substrate to (12,13) between and make described substrate to (12,13) sept (17) that keeps preset distance between, described sept (17) is arranged on described substrate to (12,13) marginal portion also contacts (12,13) with described substrate.

32. display medium as claimed in claim 19 (10) is characterized in that, described electrode (12a, 13a) one of centering comprise spaced apart, and first electrode (12a1) that is arranged alternately and second electrode (12a2);

Wherein, described first medium (30a) is located on the corresponding position, position with described first electrode (12a1), and described second medium is located on the corresponding position, position with described second electrode (12a2), to form predetermined pattern.

33. display medium as claimed in claim 32 (10), it also comprises:

To the affinity of described first medium (30a) greater than first surface processing section (19a) to the affinity of described second medium (30b); And

To the affinity of described second medium (30b) greater than second surface processing section (19b) to the affinity of described first medium (30a),

It is characterized in that described first surface processing section (19a) is located on the surface of described first electrode (12a1), described second surface processing section (19b) is located on the surface of described second electrode (12a2).

34. an electrophoretic display device (EPD) (1), it comprises:

Display medium as claimed in claim 32 (10); And

Electric control unit (70), in order to be controlled at independently described first electrode (12a1) and and described first electrode (12a1) electrode of opposite between the electric field that produces, and second electrode (12a2) and and described second electrode (12a2) electrode of opposite between the electric field that produces.

35. electrophoretic display device (EPD) as claimed in claim 34 (1) is characterized in that, described electric control unit (70) is controlled electric field independently by the voltage that described first electrode (12a1) or described second electrode (12a2) is applied the different driving waveform.

36. method of making display medium (10), described display medium (10) comprises pair of substrate (12 separate and that be arranged in parallel, 13) and be located at described substrate to (12,13) between and comprise the electrophoretic medium (30) of charged particle (31), by at described substrate to (12,13) electric field that produces between moves the described charged particle (31) that is included in the described electrophoretic medium (30), thus the conversion show state;

Described manufacture method comprises:

Medium layout operation, this operation is in order to described electrophoretic medium (30) with at least at room temperature have flowability and the potpourri of the separation medium (32) that is separated with described electrophoretic medium (30) is located at described substrate to (12,13) at least one substrate in and the face another substrate (12,13) opposite side; And

Separator forms operation, this operation is located at described substrate to (12 by making in described medium layout operation, 13) described electrophoretic medium (30) and described separation medium (32) in the lip-deep potpourri of at least one substrate are separated, thereby be provided as the described separation medium (32) of separator, in order to separate described electrophoretic medium (30).

37. the method for manufacturing display medium as claimed in claim 36 (10), it also comprises surface treatment procedure, this operation is in order to provide the affinity of described electrophoretic medium (30) greater than the first surface processing section (19a) to the affinity of described separation medium (32), it is located at described substrate to (12,13) at least one substrate in another substrate (12,13) being used on the face of opposite side is provided with on the position of described electrophoretic medium (30), and provide the affinity of described separation medium (32) greater than second surface processing section (19b) to the affinity of described electrophoretic medium (30), it is located at described substrate to (12,13) at least one substrate in and the face another substrate (12,13) opposite side and the corresponding position of shape described separation medium (32).

38. the method for manufacturing display medium as claimed in claim 36 (10) is characterized in that, described charged particle (31) to the affinity of described electrophoretic medium (30) greater than affinity to described separation medium (32).

39. the method for manufacturing display medium as claimed in claim 36 (10); it comprises that also diaphragm forms operation; this operation is handled described substrate (12 in described surface treatment procedure; 13) before the surface; by at described electrode (12a; 13a) apply the liquid that comprises fluorochemicals on the right surface, thereby (12a 13a) forms the diaphragm (18) of bleeding resistance on the right surface at described electrode.

40. method of making display medium (10), described display medium (10) comprises pair of substrate (12 separate and that be arranged in parallel, 13), charged particle (31) and be located at described substrate to (12,13) between and comprise the electrophoretic medium (30) of charged particle (31), by at described substrate to (12,13) electric field that produces between makes the charged particle (31) that comprises in the described electrophoretic medium (30) thereby migration takes place changes show state;

Described manufacture method comprises:

Medium layout operation, this operation is located at described substrate to (12 in order to the described electrophoretic medium (30) that will comprise first medium (30a) that presents first color and the potpourri of second medium (30b) that presents second color, 13) at least one substrate in another substrate (12,13) on the face of opposite side, described second medium (30b) at least at room temperature can be separated with described first medium (30a); And

The medium separation circuit, this operation is separated by make described first medium (30a) and described second medium (30b) in the described electrophoretic medium (30) that is provided with in medium layout operation, thereby forms predetermined pattern with described first medium (30a) and described second medium (30b).

41. the method for manufacturing display medium as claimed in claim 40 (10), it is characterized in that, be separately positioned on described substrate to (12,13) electrode (12a on the opposite face, 13a) centering electrode comprises first electrode (12a1) and second electrode (12a2) spaced apart and that be arranged alternately

Described manufacture method also comprises surface treatment procedure, this operation is in order to be provided with on the surface of described first electrode (12a1) the affinity of described first medium (30a) greater than the first surface processing section (19a) to the affinity of described second medium (30b), and on the surface of described second electrode (12a2), be provided with the affinity of described second medium (30b) greater than second surface processing section (19b) to the affinity of described first medium (30a)

Described medium separation circuit is by optionally being provided with described electrophoretic medium (30) to form described predetermined pattern, thereby at described first medium (30a) and described second medium (30b) when being separated, described first medium (30a) is located on the position corresponding to described first electrode (12a1), and described second medium (30b) is located on the position corresponding to described second electrode (12a2).

42. the method for manufacturing display medium as claimed in claim 41 (10); it comprises that also diaphragm forms operation; this operation is handled in described surface treatment procedure before the surface of described first electrode (12a1) and described second electrode (12a2); by at described electrode (12a; 13a) apply the liquid that comprises fluorochemicals on the right surface; thereby (12a 13a) forms the diaphragm (18) of bleeding resistance on the right surface at electrode.

43. the method for manufacturing display medium as claimed in claim 40 (10), it is characterized in that, described charged particle (31) comprise to the affinity of described first medium (30a) greater than to first particle (31a) of the affinity of described second medium (30b) and to the affinity of described second medium (30b) greater than second particle (31b) to the affinity of described first medium (30a).

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