JP2011227285A - Production method of image display medium, image display medium and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an image display medium, an image display medium and an image display device capable of successfully switching a display color by electrophoresis, even selectively charging colored electrophoretic particles.SOLUTION: An image display medium includes a pair of substrates, a partition for dividing a plurality of spaces provided between the substrates, and a particle dispersion liquid including electrophoretic particles and charged in a space. The electrophoretic particles include a plurality of colored electrophoretic particles and white electrophoretic particles. The colored electrophoretic particles in multiple colors are respectively charged in predetermined spaces, and the white electrophoretic particles are charged in each of the plurality of spaces. A production method of the image display medium includes a partition formation process for forming the partition on the substrate, a first charging process for charging a colored electrophoretic particle dispersion liquid wherein the colored electrophoretic particles are dispersed in a first dispersion medium, in the predetermined space, an evaporation process for evaporating part of the first dispersion medium from the colored electrophoretic particle charged dispersion liquid, and a second charging process for charging a white electrophoretic particle dispersion liquid wherein the white electrophoretic particles are dispersed in a second dispersion medium, in each of the plurality of spaces.

Description

  The present invention relates to a method for manufacturing an image display medium that switches between an image display state and a non-display state by moving charged white or colored particles in the direction of an electric field based on the principle of electrophoresis, and manufacturing the image display medium The present invention relates to an image display medium and an image display device manufactured by the method.

Conventionally, CRT (cathode-ray) has been used as a terminal for displaying images such as text, still images, and moving images
tube) and liquid crystal displays are used. They can display and rewrite digital data instantly, but it is difficult to always carry the device around, and it has many drawbacks such as eye fatigue when working for a long time and display when turning off the power. is there. On the other hand, when a character or a still image is distributed or stored as a document, it is recorded on a paper medium by a printer. This paper medium is widely used as a so-called hard copy. Hard copy is easier to read than display, less fatigue, and can be read freely. Furthermore, it has the characteristics that it is lightweight and can be carried freely. However, the hard copy is discarded and recycled after it is used. However, since the recycling requires a lot of labor and cost, there remains a problem in terms of resource saving.

  There is a great need for rewritable and paper-like display media that have the advantages of both the above-mentioned display and hard copy. Up to now, polymer-dispersed liquid crystals, bistable cholesteric liquid crystals, electrochromic devices, electrophoretic devices A display medium using the above has been proposed, and has attracted attention as a display medium that can display brightly in a reflective display type and has a memory property. Among them, the one using an electrophoretic element is excellent in terms of display quality and power consumption during display operation, and is disclosed in, for example, Patent Document 1 and Patent Document 2. In the electrophoretic display medium, a dispersion liquid in which a plurality of electrophoretic particles having a color different from the color of the dispersion medium is dispersed in a colored dispersion medium is sealed between a pair of transparent electrodes. In this case, the electrophoretic particles (hereinafter also simply referred to as electrophoretic particles) are charged on the surface in the dispersion medium, and the particles can be moved by forming an electric field between the transparent electrodes. For example, when a charge opposite to the charge of the electrophoretic particles is applied to one of the transparent electrodes, the electrophoretic particles are attracted to the electrode and deposited near the electrode, and the color of the electrophoretic particles is observed. Conversely, when the same charge as that of the electrophoretic particles is applied, the electrophoretic particles move to the opposite side, and thus the color of the dispersion medium is observed. By changing the charge on the electrode surface in this way, various displays can be performed by applying the principle of changing the observed color.

  In the case described above, since two colors can be displayed by one pixel, full-color display cannot be performed as a display medium. As a means for performing full color display, it has been proposed to arrange cells for displaying three primary colors in a display medium. For example, a technique for performing full color display by overlaying a color filter on an electrophoretic display medium for performing black and white display is known. As another method, Patent Document 3 discloses a method in which a liquid in which white particles are dispersed is applied to all spaces and then filled with a liquid in which different color dyes are dissolved in each of a plurality of spaces. Furthermore, Patent Document 4 discloses a technique for displaying three colors by an electrophoretic liquid in which three types of dispersible particles having different optical characteristics and charging characteristics are dispersed in a solvent, and displaying a full color by arranging the three primary colors. Yes.

  As described in Patent Document 3, in order to coat each color cell in an image display medium, a droplet is ejected from a nozzle like an ink jet and filled in a selected space. In order to avoid nozzle clogging, a white particle dispersion common to all cells is first applied to all spaces, and then a color dye solution is ejected by inkjet. In this case, it is difficult to fill the color dye solution without excess or deficiency with respect to the volume of the space, leading to problems such as overflow to adjacent cells or mixing of bubbles during space sealing. On the contrary, in Patent Document 5, first, the color particle solution or dispersion is filled in a pattern by ink jet, and then the charged particle dispersion is filled in the entire space. In this case, if the colorant solution is a dye, Although there is no particular problem, in the case of a colorant dispersion with a pigment, the pigment is solidified and aggregated by removing the carrier solvent. It is difficult to perform display color switching well.

  As a means for solving problems caused by particle drying, Patent Document 6 discloses a method of coating and dispersing a dispersing agent for electrophoretic particles. However, the condition of drying is unchanged, and the effect is limited. is there.

  In view of such a situation, the present invention provides a method for manufacturing an image display medium capable of satisfactorily switching display colors by electrophoresis even when colored electrophoretic particles are selectively filled, and a method for manufacturing the image display medium. An image display medium and an image display device manufactured by the above are provided.

  As a result of intensive studies on means for solving the above problems, the inventors of the present invention are important to manufacture an image display medium without drying the selectively charged colored electrophoretic particles (pigment particles). Has found that it is only necessary to evaporate only a part of the dispersion medium contained in the liquid discharged from the nozzle, for example, to mix a non-volatile liquid into the liquid discharged from the nozzle.

That is, in order to solve the above-described problems, the image display medium manufacturing method according to the present invention, and the image display medium and the image display device manufactured by the image display medium manufacturing method are specifically described in the following (1) to It has the technical features described in (5).
(1): having a pair of substrates, a partition provided between the pair of substrates and dividing a plurality of spaces, and a particle dispersion liquid containing electrophoretic particles and filled in the spaces. The electrophoretic particles include colored electrophoretic particles composed of a plurality of colors and white electrophoretic particles, and the colored electrophoretic particles composed of the plurality of colors each in a desired space in the plurality of spaces. An image display medium manufacturing method, wherein the white electrophoretic particles are filled in any of the plurality of spaces, and a partition is provided on at least one of the pair of substrates. A partition forming step and a desired space among a plurality of spaces partitioned by the partition are selected, and a colored electrophoretic particle dispersion liquid in which the colored electrophoretic particles are dispersed is filled in a first dispersion medium. First filling step and filling The white electrophoretic particles are used as the second dispersion medium in both the evaporation step of evaporating a part of the first dispersion medium from the colored electrophoretic particle dispersion and the plurality of spaces divided by the partitions. And a second filling step of filling the white electrophoretic particle dispersion in which is dispersed in the image display medium.
(2): The first dispersion medium is a mixture of (i) a liquid having a boiling point of less than 200 ° C. at normal temperature and normal pressure, and (ii) a liquid having a boiling point of 200 ° C. or higher at normal temperature and normal pressure. The method for producing an image display medium as described in (1) above.
(3): (ii) The liquid having a boiling point of 200 ° C. or higher at normal temperature and pressure is 1 or 2 or more selected from silicone oil, modified silicone oil and liquid paraffin. It is a manufacturing method of the image display medium of description.
(4): An image display medium manufactured by the method for manufacturing an image display medium according to any one of (1) to (3) above.
(5): An image display device comprising: the image display medium according to (4) above; and power supply means for supplying power to the image display medium.

  According to the configuration described in the above (1) to (5), the non-volatile dispersion medium remains even after the volatile dispersion medium is removed from the colored electrophoretic particle dispersion liquid selectively filled in the space. Since the electrophoretic particles are not completely dried, color switching of the image display medium can be performed satisfactorily.

  According to the present invention, it is possible to provide an image display medium manufacturing method capable of satisfactorily switching colors of the image display medium, and an image display medium and an image display device manufactured by the image display medium manufacturing method. it can.

It is a flowchart of the manufacturing method of the image display medium of this invention. 1 is a conceptual cross-sectional view of an image display medium of the present invention. It is a conceptual diagram of the image display apparatus of this invention.

  The method for manufacturing an image display medium according to the present invention includes a pair of substrates, a partition provided between the pair of substrates and dividing a plurality of spaces, and electrophoretic particles filled in the spaces. A plurality of colored electrophoretic particles and white electrophoretic particles, and each of the plurality of colored electrophoretic particles includes the plurality of colored electrophoretic particles. A method for manufacturing an image display medium, wherein the white electrophoretic particles are filled in a desired space, and the white electrophoretic particles are filled in any of the plurality of spaces. A partition forming step of providing a partition on at least one of the plurality of spaces divided by the partition and selecting a desired space, and coloring the colored electrophoretic particles dispersed in the first dispersion medium Filled with electrophoretic particle dispersion The first filling step, the evaporation step of evaporating a part of the first dispersion medium from the filled colored electrophoretic particle dispersion, and the plurality of spaces partitioned by the partitions And a second filling step of filling the white electrophoretic particle dispersion liquid in which the white electrophoretic particles are dispersed in the second dispersion medium.

[Method of manufacturing image display medium]
Next, the best mode for carrying out the image display medium manufacturing method according to the present invention will be described with reference to the drawings as necessary. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of a preferred embodiment of the present invention, and does not limit the scope of the claims.

  An electrophoretic display medium manufacturing method, which is an embodiment of an image display medium manufacturing method according to the present invention, will be described step by step. In this embodiment, it is assumed that one pixel performs display switching between color and white, and one full color display is performed in three cells each displaying three primary colors in the image display medium.

(Electrode formation process)
First, an electrode is formed on a substrate. The electrode can be patterned or it can be solid without being patterned. As an electrode, a metal such as Al, Ag, Ni, Cu, or a transparent conductor such as ITO, SnO ₂ , ZnO: Al is formed into a thin film by sputtering, vacuum deposition, CVD, coating, etc. Or what mixed the electrically conductive agent with the solvent or the synthetic resin binder, and apply | coated etc. is formed and used as a conductive layer. Conductive agents include cationic polyelectrolytes such as polymethylbenzyltrimethyl chloride and polyallylpolymethylammonium chloride, anionic polyelectrolytes such as polystyrene sulfonate and polyacrylate, and electronically conductive zinc oxide and tin oxide. Indium oxide fine powder or the like is used. The conductive layer itself may be thick enough to have a self-supporting function, or the conductive layer may be provided on a substrate having a self-supporting function (not shown), which can be preferably used in either case. However, when the surface is solid, it is preferably a transparent electrode.

(Partition formation process)
Next, a cell filled with an electrophoretic liquid (electrophoretic particle dispersion) is formed by providing a partition by photolithography or the like. The cell at this time is a space that is partitioned by a convex partition on one surface of a pair of substrates and has an opening (formed at a position facing the other substrate). This opening is closed (sealed) by attaching the other of the pair of substrates to each other in a later step, and becomes a closed space. A plurality of cells are formed on the substrate, for example, a plurality of cells are formed in a lattice shape.
Here, when the electrode is patterned, it is preferable to form a cell in accordance with the pattern of the electrode. In order to form the cell, an opening may be formed by applying a photoresist resin to the surface of the substrate on which the electrode is disposed, and then removing the resin at the electrode portion to be paired.

(First filling step)
Next, as shown in FIGS. 1A and 1B, the colored electrophoretic particles 1 are injected (filled) by selecting a desired space among a plurality of spaces. As a method of injecting at this time, a method of injecting using an inkjet or a nozzle of a dispenser is preferable.

  As an example of the colored electrophoretic particle 1, as cyan colored particles, for example, phthalocyanine blue, methylene blue, Victoria blue, methyl violet, aniline blue, ultramarine blue, or the like can be used. As magenta colored particles, for example, rhodamine 6G lake, dimethylquinacridone, watching red, rose bengal, rhodamine B, alizarin lake and the like can be used. As yellow colored particles, for example, chrome yellow, benzidine yellow, Hansa yellow, naphthol yellow, molybdenum orange, quinoline yellow, tartrazine and the like can be used. In some cases, black electrophoretic particles can be used, and as black colored particles in that case, for example, carbon black, aniline black, furnace black, lamp black, or the like can be used.

  At this time, the colored migrating particles 1 are dispersed in the first dispersion medium 2. It is preferable to use a mixed liquid in which a part of the first dispersion medium 2 is nonvolatile and the rest is volatile. Further, the dispersibility of the colored electrophoretic particles is preferably good, and a nonpolar organic solvent is preferably used.

  In the present invention, liquid (i) having a boiling point of less than 200 ° C. at normal temperature and pressure is selected as such a nonpolar organic solvent, and paraffinic hydrocarbons such as pentane, hexane, heptane, and octane, isohexane, isooctane, etc. Isoparaffinic hydrocarbons, alkyl naphthenic hydrocarbons such as liquid paraffin, aromatic hydrocarbons such as benzene, toluene, xylene, alkylbenzene, solvent naphtha, dimethyl silicone oil, phenylmethyl silicone oil, dialkyl silicone oil, alkylphenyl silicone oil Among these, silicone oils such as cyclic polydialkylsiloxane or cyclic polyalkylphenylsiloxane having a boiling point of less than 200 ° C. can be mentioned. These can be used alone or in combination of two or more.

  The non-volatile solvent is selected from those having a boiling point of 200 ° C. or higher at room temperature and pressure. In the present invention, the liquid (ii) having a boiling point of 200 ° C. or higher at normal temperature and normal pressure is selected from silicone oil, modified silicone oil, and liquid paraffin. Boiling point among silicone oils such as those having a viscosity of 2 cs or more for silicone oils, and silicone oils such as phenylmethyl silicone oil, dialkyl silicone oil, alkylphenyl silicone oil, cyclic polydialkylsiloxane or cyclic polyalkylphenylsiloxane for modified silicone oils May be liquid paraffin having a boiling point of 200 ° C. or higher. These can be used alone or in combination of two or more.

  In order to control the dispersibility of the colored electrophoretic particles 1, a dispersant or the like may be further added to the first dispersion medium 2 as necessary.

(Evaporation process)
When the liquid is poured into the cell, the volatile dispersion medium component evaporates, so that only the colored electrophoretic particles 1 and the non-volatile component remain in the cell [FIG. 1 (c)].

(Second filling step)
Next, as shown in FIG. 1D, a white electrophoretic particle dispersion is injected into the entire space. The entire space can be filled with the white electrophoretic particle dispersion by injection with a squeegee, but is not limited thereto. When the white electrophoretic particle dispersion liquid is filled, the colored electrophoretic particles are re-dispersed in the cell, and the electrophoretic particles are dispersed in the dispersion medium (the first dispersion medium excluding a part of the evaporated liquid and the second dispersion medium). Both the electrophoretic particles and the white electrophoretic particles are dispersed [FIG. 1 (e)].

  As an example of the white electrophoretic particles 3 constituting the white electrophoretic particle dispersion, solid particles of metal oxides such as silicon dioxide, aluminum oxide, and titanium oxide can be used. In FIG. 1, reference numeral 4 denotes a second dispersion medium, which is preferably a nonpolar organic solvent having high electrical insulation. It may be the same as or different from the dispersion medium component used in the colored electrophoretic particle dispersion.

  The surface of the white or colored electrophoretic particles is preferably provided with a graft chain of a polymer component that is compatible with the dispersion medium for the purpose of improving the dispersion stability in the dispersion medium. In order to form the polymer component on the surface of the electrophoretic particle, a functional group contributing to the polymerization reaction may be added to the surface of the white or colored electrophoretic particle, and a known method can be used. In the case of particles having a metal oxide surface such as titanium oxide, it is preferable to treat with a coupling agent having a functional group that contributes to the polymerization reaction. For example, when vinyl groups are added to the surface. What is necessary is just to make it react with the silane coupling agent which has vinyl groups, such as 3- (trimethoxysilyl) propyl methacrylate. In addition, when the particles are carbon black, it is known that a vinyl group can be imparted to the carbon black surface by reacting with, for example, vinyl aniline. Electrophoretic particles in which a polymer component is grafted are obtained by graft polymerization reaction of particles and functional groups that contribute to the polymerization reaction. Alternatively, as disclosed in Japanese Patent Application Laid-Open No. 2005-265938, a monomer is added in a state where white or colored electrophoretic particles are dispersed in a non-polar solvent, and dispersed on the surface of white or colored electrophoretic particles simultaneously with polymerization. It is also possible to form a polymer layer having a portion having a high affinity for the medium.

  The mass ratio of the white or colored electrophoretic particles in the white or colored electrophoretic particle dispersion is appropriately set so that a desired concentration of color can be obtained, but about 1 to 50 mass% is appropriate. These components are added to a nonpolar solvent and mixed and dispersed to obtain an electrophoretic particle dispersion. In this case, a known dispersing means such as a homogenizer, a ball mill, a sand mill, or an attritor may be used as the dispersing means.

(Sealing process)
Finally, all the spaces are sealed. As a means for sealing the space, there is a method in which a substrate coated with an adhesive is bonded. In this case, examples of the substrate include a glass substrate and a plastic substrate on which an electrode is formed. The substrate may be a solid electrode, a segment pattern electrode, or a substrate on which a TFT circuit is formed. .

  By disposing different electrophoretic display liquids (particle dispersions containing colored electrophoretic particles of different colors) in adjacent cells, an electrophoretic display element for multicolor display can be obtained.

[Image display medium]
An embodiment of the image display medium of the present invention will be described with reference to FIG. In FIG. 2, reference numeral 10 denotes an electrode made of a conductive layer, which is light transmissive. Reference numeral 11 denotes a cell sealing layer. Reference numerals 12, 13, and 14 denote individual electrodes. In FIG. 2, 15, 16 and 17 inside the cell are colored electrophoretic particles and have different colors, and 18 is white electrophoretic particles. The dispersion medium 19 is a dispersion medium (first dispersion medium) filled with a non-volatile component remaining in the process of injecting colored electrophoretic particles (a component excluding a part of the first dispersion medium that has evaporated) and a white electrophoretic particle dispersion. 2 dispersion medium). It is preferable that the colored electrophoretic particles 15, 16, and 17 have the same charging polarity, and only the white electrophoretic particles 18 have a different charging polarity from the colored electrophoretic particles. Since an electric field can be generated between the electrodes 11 and 12 to 14, the white or colored electrophoretic particles can move reliably. In order to perform the display, a voltage applying unit capable of applying a voltage to the electrode may be prepared. As for the common electrode 11, a voltage may be applied by a voltage applying means similarly to the individual electrodes 12, 13, and 14, or may be grounded. In any case, the electrophoretic particles move according to their charge polarity and charge amount due to the electric field generated by the potential difference between the common electrode 11 and the individual electrodes 12, 13, and 14.

(Image display device)
An image display apparatus according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, the image display device 20 of the present invention includes an image display medium 21, and includes an information input means 22, a drive circuit (not shown), an arithmetic circuit, an internal memory, a power supply means (power supply means), and the like. I have. The electrodes in the display medium form a dot matrix, display the desired color by controlling the voltages of the two individual electrodes of the designated dot, and display the image as a whole. In FIG. 3, 23 is a housing. The power supply means may be provided with internal power such as a battery or a power receiving device such as an outlet receiving power from an external power source.

  The invention is explained in more detail by means of examples. However, the present invention is not limited to the following examples. In addition, in description of an Example and a comparative example, unless otherwise indicated, a part,%, etc. are a mass reference | standard.

Example 1
[Preparation of white electrophoretic particles]
A mixed solvent of 93 parts of ethanol and 7 parts of water was prepared in a reaction vessel equipped with a stirrer, and the pH was adjusted to 4.5 with glacial acetic acid. After dissolving 16 parts of 3- (trimethoxysilyl) propyl methacrylate, 100 parts of titanium oxide was added and stirring was continued for 10 minutes. Next, 180 parts of ethanol was added and stirred, and the solid content recovered by centrifugation was left to stand for one day and then vacuum dried at 70 ° C. for 4 hours to obtain surface-treated titanium oxide.

  Subsequently, 130 parts of toluene was prepared in a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, and 100 parts of lauryl methacrylate was dissolved. To this was added 75 parts of the above surface-treated titanium oxide and 50 parts of toluene in which 0.5 part of azobisisobutyronitrile was dissolved, and the mixture was heated and stirred at 70 ° C. for 6 hours in a nitrogen atmosphere. After completion of the reaction, the solid content was washed with toluene and centrifuged repeatedly, and finally vacuum dried at 70 ° C. for 4 hours to obtain the desired white electrophoretic particles.

[Production of magenta electrophoretic particles]
Quinacridone (Pigment Red 122) was used as a magenta pigment. 2-vinylaniline was diazo-coupled to the surface of the quinacridone particles, and a graft chain was formed by graft polymerization from a vinyl group on the surface of the quinacridone particles with 2-ethylhexyl methacrylate. After completion of the reaction, the solid was washed with toluene and centrifuged repeatedly, and finally dried in vacuo at 70 ° C. for 4 hours to obtain the desired magenta (colored) electrophoretic particles.

[Production of display medium]
A square cell partition (partition) having the same pitch is formed of a photoresist on a TFT substrate on which a square individual electrode having a side of 200 μm and a pitch of 225 μm is formed. SU-8 (manufactured by Nippon Kayaku Micro Corporation) is used as the photoresist. The thickness of the cell partition is 15 μm, the height of the cell partition is 50 μm, and the positions are aligned so that one individual electrode fits in one cell space. ; Partition formation process

  In the formed cell, 2 parts of the magenta electrophoretic particles, 1 cs of silicone oil (Shin-Etsu Chemical KF96L-1cs: boiling point 153 ° C.) 94 parts, 5 cs of silicone oil (Shin-Etsu Chemical KF96L-5cs: not boiling at room temperature) Four parts of colored electrophoretic particle dispersion 2nL is injected into the selected cell using a dispenser. A first filling step

  After standing for 30 minutes (; evaporation step), white electrophoresis comprising 40 parts of the above white electrophoretic particles, 59.5 parts of isoparaffinic hydrocarbon (Exxon Chemical Isopar G), and 0.5 part of a dispersant (Lubrisol Solsper 17000). The particle dispersion is poured by a slit coater so as to fill all cells. A second filling step

  After removing the excess electrophoresis solution, a sealing film is formed on the solution to prevent the electrophoresis solution from drying. The sealing film used was a gelatin resin that was incompatible with the electrophoresis solution, and a polyoxyethylene-based surfactant was added to reduce the surface tension with the electrophoresis solution. In the state which heated the gelatin resin aqueous solution to about 40 degreeC, it apply | coats on an electrophoresis liquid using a slit coater, and gelatin is dried and a sealing film is formed. ; Sealing process

  Next, an electrophoretic display medium of the present invention is obtained by applying an adhesive on the sealing film and adhering a PET film on which ITO is formed.

[Display operation]
When + 15V was applied to the individual electrode into which the magenta particle dispersion was injected, magenta was displayed, and when -15V was applied, white was displayed. The white reflectance at this time was 45%.

(Comparative Example 1)
[Production and operation of image display medium]
In Example 1, a magenta electrophoretic particle dispersion was used except that a colored electrophoretic particle dispersion composed of 2 parts of the magenta electrophoretic particles and 98 parts of 1 cs silicone oil (Shin-Etsu Chemical KF96L-1cs: boiling point 153 ° C.) was used. When a cell was produced and displayed in the same manner as in Example 1, the display could not be switched because the magenta particles remained fixed to the electrode.

  As mentioned above, according to the manufacturing method of the image display medium which concerns on this invention, the image display medium which can perform the display color switching favorably by electrophoresis can be produced.

1: Colored electrophoretic particles 2: Dispersion medium 3: White electrophoretic particles 4: Dispersion medium 10: Electrode 11: Sealing layers 12-14: Individual electrodes 15-17: Colored electrophoretic particles 18: White electrophoretic particles 19: Dispersion medium 20: Image display device 21: Image display medium 22: Information input means 23: Housing

JP-A-5-173194 Japanese Patent No. 2612472 Japanese Patent No. 4085610 JP 2009-9092 A Special table 2007-537493 JP 2007-279375 A

Claims (5)

A pair of substrates, a partition provided between the pair of substrates and partitioning a plurality of spaces, and a particle dispersion liquid containing electrophoretic particles and filled in the spaces,
The electrophoretic particles include colored electrophoretic particles composed of a plurality of colors, and white electrophoretic particles,
The colored electrophoretic particles composed of the plurality of colors are each filled in a desired space in the plurality of spaces,
The white electrophoretic particles are filled in any of the plurality of spaces, and are manufacturing methods of an image display medium,
A partition forming step of providing a partition on at least one of the pair of substrates;
A first filling step of selecting a desired space among a plurality of spaces divided by the partition and filling a colored electrophoretic particle dispersion liquid in which the colored electrophoretic particles are dispersed in a first dispersion medium. When,
An evaporation step of evaporating a part of the first dispersion medium from the filled colored electrophoretic particle dispersion;
A second filling step of filling any of the plurality of spaces partitioned by the partition with a white electrophoretic particle dispersion liquid in which the white electrophoretic particles are dispersed in a second dispersion medium. A method for manufacturing an image display medium.   The first dispersion medium is a mixture of (i) a liquid having a boiling point of less than 200 ° C. at normal temperature and normal pressure, and (ii) a liquid having a boiling point of 200 ° C. or higher at normal temperature and normal pressure. The manufacturing method of the image display medium of Claim 1.   3. The image display medium according to claim 2, wherein the liquid having a boiling point of 200 ° C. or higher at normal temperature and normal pressure is one or more selected from silicone oil, modified silicone oil, and liquid paraffin. Manufacturing method.   An image display medium manufactured by the method for manufacturing an image display medium according to claim 1.   An image display device comprising: the image display medium according to claim 4; and power supply means for supplying power to the image display medium.