JP5278284B2 - ELECTRO-OPTICAL DEVICE, ELECTRONIC DEVICE, COLORED LAYER FORMING METHOD, AND ELECTRONIC OPTICAL DEVICE MANUFACTURING METHOD - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide an electro-optical device for displaying sharp color images. <P>SOLUTION: The electro-optical device includes a first substrate, a second substrate facing the first substrate, an electro-optical layer which is disposed between the first and the second substrates and which includes electrophoretic particles and a dispersion medium, and a colored layer which is located at a position corresponding to the electro-optical layer and which includes color elements of at least one color. At least a part of the dispersion medium is colored with substantially the same color as the one color. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an electro-optical device, an electronic apparatus, a colored layer forming method, and an electro-optical device manufacturing method.

  As a non-luminous display device, an electrophoretic display device using an electrophoretic phenomenon is known. The electrophoresis phenomenon is a phenomenon in which particles migrate due to Coulomb force when an electric field is applied to a dispersion system in which fine particles (electrophoretic particles) are dispersed in a liquid (solvent).

  The basic structure of the electrophoretic display device is such that one electrode and the other electrode face each other at a predetermined interval, and a dispersion system is enclosed between them. When a potential difference is applied between the two electrodes, the electrophoretic particles charged according to the direction of the electric field are attracted to one of the electrodes. Here, if the solvent is dyed with a dye and the electrophoretic particles are composed of pigment particles, the observer can see the color of the electrophoretic particles or the color of the dye. Therefore, an image can be displayed by patterning the electrodes and controlling the voltage applied to them.

  The above-described electrophoretic display device has attracted attention as a technique that replaces a liquid crystal display device or the like. However, particularly when applied to a display device application of an electronic apparatus, it is necessary to realize color display.

SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device capable of clear color display at a low cost.
An object of the present invention is to provide an electronic apparatus including the above electro-optical device.
An object of the present invention is to provide a method for forming a colored layer suitable for use in an electro-optical device.
An object of the present invention is to provide a method for manufacturing the above electro-optical device.

In order to solve the above problems, an electro-optical device according to an aspect of the invention includes a first substrate, a second substrate facing the first substrate, and between the first substrate and the second substrate. An electro-optic layer having electrophoretic particles and a dispersion medium, a colored layer having a plurality of colored portions arranged on the electro-optic layer side of the first substrate and having different color tones, and the first substrate A common electrode disposed on the electro-optic layer side of the substrate; and a pixel electrode disposed on the electro-optic layer side of the second substrate, wherein the colored layer exhibits a color tone. And the partition wall disposed between the colored portion exhibiting another color tone, and the electrophoretic particles and the dispersion medium are disposed in a region overlapping the partition wall in a plan view. And
In the electro-optical device, the electrophoretic particles preferably include white particles.
In the electro-optical device, a plurality of the pixel electrodes are disposed on the electro-optical layer side of the second substrate, and each of the pixel electrodes corresponds to one of the plurality of coloring portions in a plan view. It is preferable to arrange | position.
In the electro-optical device, the electro-optical layer may further include a capsule that accommodates the dispersion medium and the electrophoretic particles.
In the electro-optical device, the dispersion medium accommodated in each of the capsules may have a color tone corresponding to any of the plurality of colored portions.
In the electro-optical device, the colored layer may be provided between the common electrode and the electro-optical layer, and the colored layer may have conductivity.
Another aspect of the present invention is an electro-optical device having the following configuration, the electronic device, a method of forming a colored layer to provide a method of manufacturing an electro-optical device.

The present invention provides an electro-optical device comprising: an electro-optical layer having electrophoretic particles and a dispersion medium; and a colored layer provided on a viewing side of the electro-optical layer. I will provide a.
That is, the present invention provides an electro-optical device colored by a colored layer provided on the viewing side of the electro-optical layer.

Next, the present invention further includes a first substrate and a second substrate facing the first substrate, wherein the first substrate and the second substrate are the electro-optical devices described above. An electro-optical device is provided in which the electro-optical layer and the colored layer are disposed between the substrate and the substrate.
According to the above configuration, it is not necessary to provide a separate color filter, and an electro-optical device capable of color display can be provided at low cost.

  Next, the present invention further includes a first electrode provided on the first substrate and a second electrode provided on the second substrate in the electro-optical device described above, An electro-optical device is provided in which the electro-optical layer and the colored layer are disposed between a first electrode and the second electrode.

Next, in the electro-optical device described above, the present invention includes a plurality of dot regions, the colored layer includes a plurality of color elements having different colors, and each of the plurality of dot regions An electro-optical device is provided that corresponds to at least one color element of a plurality of color elements.
According to the above configuration, an electro-optical device capable of displaying different colors for each dot region can be provided.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein each of the plurality of dot regions is separated by a partition wall.
According to the above configuration, since the dispersion medium of the electro-optic layer is divided for each dot region, an electro-optic device having excellent display quality and reliability without causing non-uniform electrophoretic particle distribution. Can be provided.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein the electro-optical layer further includes a capsule containing the dispersion medium and the electrophoretic particles. .
According to the above configuration, an electro-optical device excellent in display quality and reliability in which the flow range of the electrophoretic particles is regulated in the capsule and the distribution of the electrophoretic particles does not occur unevenly is provided. Can do.

Next, the present invention provides the electro-optical device described above, including a plurality of the capsules, wherein the colored layer includes a plurality of color elements having different colors, and each of the plurality of capsules includes the plurality of capsules. An electro-optical device is provided that corresponds to at least one of the color elements.
According to the above configuration, since one or more color elements are arranged for each capsule, it is possible to further prevent non-uniform distribution of the electrophoretic particles and to have excellent display quality and reliability. Can be provided.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein the colored layer has conductivity.
According to the said structure, the electrical capacitance formed in the colored layer by the colored material disperse | distributed in the colored layer can be canceled by the colored layer which has electroconductivity. In other words, since the voltage applied to the electro-optical layer for moving the electrophoretic particles can be lowered, an electro-optical device that can be driven at a low voltage can be obtained.

Next, in the electro-optical device, the present invention is arranged between the first substrate, the second substrate facing the first substrate, and the first substrate and the second substrate. An electro-optical layer having electrophoretic particles and a dispersion medium, and a colored layer provided corresponding to the electro-optical layer and including at least one color element, wherein the dispersion medium includes at least An electro-optical device is provided in which a part thereof is colored substantially the same color as the one color.
According to the above configuration, the colored layer disposed corresponding to the electro-optic layer provided between the first and second substrates and the dispersion medium of the electro-optic layer are colored in substantially the same color. Therefore, a clear color display is possible, and a low-cost electro-optical device can be provided.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein the color elements contained in the dispersion medium are dispersed in the colored layer.
According to the above configuration, since the colored layer can be colored by the color element for coloring the dispersion medium, an electro-optical device capable of clear color display at low cost without using a separate color filter is provided. Can do. Further, it is possible to cope with the change of the color type of the colored layer only by changing the type of the color element.

Next, in the electro-optical device described above, the present invention includes a plurality of dot regions, the colored layer includes a plurality of color elements having different colors, and each of the plurality of dot regions It corresponds to at least one color element of a plurality of color elements, and the dispersion medium is colored in substantially the same color as the corresponding color element in the dot region. An optical device is provided.
According to the above configuration, since the colored layer is provided for each dot, it is possible to provide an electro-optical device that can realize an arbitrary display in an arbitrary color.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein each of the plurality of dot regions is separated by a partition wall.
According to the above configuration, the dispersion medium in each dot region separated by the partition can be colored in an arbitrary color, and an electro-optical device that exhibits a different color for each dot region can be configured.

  Next, according to the present invention, in the electro-optical device described above, an electrode is provided on the inner surface side of the first substrate, and the colored layer is provided between the electrode and the electro-optical layer. An electro-optical device is provided.

Next, according to the present invention, in the electro-optical device described above, the member constituting the colored layer is provided with a plurality of holes, and the dispersion medium is colored with a diameter equal to or smaller than the holes. An electro-optical device is provided that includes a material and has a larger diameter of the electrophoretic particles than the pores.
According to the above configuration, only the coloring material contained in the dispersion medium is dispersed to the colored layer side through the pores, and the electrophoretic particles can move only in the dispersion medium. An electrophoretic device having excellent reliability can be provided without restricting the flow of electrophoretic particles therein.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein the coloring material includes a dye.
According to the above configuration, since the coloring material contains a dye, the coloring material is excellent in fluidity in the dispersion medium and can be easily dispersed in the coloring layer.

Next, the present invention provides the electro-optical device according to the electro-optical device described above, wherein the electro-optical layer further includes a capsule containing the dispersion medium and the electrophoretic particles. .
According to the above configuration, since the movement of the electrophoretic particles is limited in the capsule, the electrooptic device can be provided with excellent reliability without uneven distribution of the electrophoretic particles in the electrooptic layer. .

Next, the present invention provides the electro-optical device described above, including a plurality of the capsules, wherein the colored layer includes a plurality of color elements having different colors, and each of the plurality of capsules includes the plurality of capsules. The electro-optical device corresponds to at least one of the color elements, and the dispersion medium is colored in substantially the same color as the corresponding color element in the capsule. I will provide a.
According to the above configuration, the state of the electro-optic layer corresponding to each color element can be controlled, and the capsule and the colored layer are substantially the same color, so that a clear color display is obtained. be able to.

Next, the present invention provides an electronic apparatus including the electro-optical device described above as a display unit.
According to the above configuration, it is possible to provide an electronic device including a display unit capable of clear color display at a low cost.

Next, the present invention provides a method for forming a colored layer, a step of moving a relative position between a porous member and a head for discharging the material, and a step of discharging the material onto the porous member. And the material comprises a coloring material smaller than a hole provided in the member.
According to the above configuration, since the material containing the coloring material that is dispersed in the porous member and can color the member can be disposed at any position on the porous member, different color types It is possible to efficiently arrange the material including the coloring material.

Next, the present invention provides the colored layer forming method described above, wherein the coloring material contains a dye.
According to the said structure, a coloring material becomes easy to be disperse | distributed in the said porous member by containing the said dye, and the said porous member can be colored uniformly.

Next, the present invention provides a method of manufacturing an electro-optical device having a plurality of dot regions, the step of moving a relative position between a head that discharges a material and a substrate on which a porous member is disposed for each dot. And discharging the material from the head toward the porous member, the material comprising a coloring material having a diameter smaller than a hole provided in the member. An electro-optical device manufacturing method is provided.
According to the said structure, the said layer can be arrange | positioned in the arbitrary positions on the said porous member, and the colored layer can be formed by coloring the said porous member with the coloring material contained in the said material, An electro-optical device capable of color display using the colored layer can be efficiently manufactured.

Next, the present invention provides the electro-optical device described above, wherein the material includes electrophoretic particles, and the diameter of the electrophoretic particles is larger than a hole provided in the member. An optical device manufacturing method is provided.
According to the above configuration, since the electrophoretic particles do not enter the inside of the porous member, the electrophoretic particles are not hindered by the porous member, and the display device has excellent display quality and reliability. An apparatus can be provided.

FIG. 1 is a cross-sectional configuration diagram of an electrophoretic display device according to a first embodiment of the present invention. FIG. 2 is a plan view of the electrophoretic display device shown in FIG. FIG. 3 is a cross-sectional configuration diagram of an electrophoretic display device according to the second embodiment of the present invention. FIG. 4 is a plan view of the electrophoretic display device shown in FIG. FIG. 5 is an enlarged cross-sectional configuration diagram illustrating the electrophoretic layer illustrated in FIG. 3. FIG. 6 is a cross-sectional configuration diagram illustrating another configuration example of the electrophoretic layer illustrated in FIG. 3. FIG. 7 is a cross-sectional configuration diagram illustrating another configuration example of the electrophoretic layer illustrated in FIG. 3. FIG. 8 is a cross-sectional configuration diagram illustrating another configuration example of the electrophoretic layer illustrated in FIG. 3. FIG. 9 is a graph showing the relationship between display brightness and contrast in the electrophoretic display device shown in FIG. FIG. 10 is a cross-sectional configuration diagram of a microcapsule provided in the electro-optical device according to the third embodiment of the present invention. 11A to 11D are cross-sectional process diagrams illustrating manufacturing processes of the electrophoretic display device according to the present invention. 12A to 12D are cross-sectional process diagrams illustrating another example of the manufacturing process of the electrophoretic display device according to the present invention. FIG. 13 is a cross-sectional process diagram illustrating an example of a method of dropping the dispersion medium illustrated in FIG. 12C. FIG. 14 is a diagram showing an example of an electronic apparatus according to the present invention. FIG. 15 is a diagram showing an example of an electronic apparatus according to the present invention. FIG. 16 is a diagram showing an example of an electronic apparatus according to the present invention. FIG. 17 is a diagram showing an example of an electronic apparatus according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic cross-sectional view showing an active matrix type electrophoretic display device which is a first embodiment of an electro-optical device according to the present invention, and FIG. 2 is a plan view of the electrophoretic display device shown in FIG. It is. Further, FIG. 1 corresponds to a cross-sectional structure along the line AA ′ shown in FIG.

  The electrophoretic device 10 shown in these drawings includes an electrophoretic layer (electro-optical layer) 11 between a first substrate 1 and a second substrate 8 that are arranged to face each other. The colored layer 4 and the common electrode 2 are sequentially formed on the inner surface side (electrophoresis layer 11 side) of the first substrate 8, and a plurality of pixel electrodes 7 a are formed on the inner surface side (electrophoresis layer 11 side) of the second substrate 8. The element part 7 which has etc. is formed. On the first substrate 1 side, the first substrate 1, the colored layer 4, and the common electrode 2 have translucency, and the outer surface of the first substrate 1 is a display surface of the electrophoresis apparatus 10. Although not shown, various peripheral circuits for driving and controlling the element unit 7 can be formed on the second substrate 8 having the element unit 7. In this embodiment, the common electrode 2 is formed on the first substrate 1 side and the element part 7 is formed on the second substrate 8 side. However, the element part 7 is formed on the first substrate 1 side. Also good.

  The first substrate 1 can be composed of a transparent substrate such as transparent glass or transparent film, and the second substrate 8 is not necessarily transparent, but can be a glass substrate or a resin film substrate, for example. Can be configured.

As shown in FIG. 1, the electrophoretic layer 11 is obtained by dispersing a plurality of electrophoretic particles 6 in a dispersion medium 5.
As the dispersion medium 5, alcohol solvents such as water, methanol, ethanol, isopropanol, butanol, octanol and methyl cellosolve, various esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, Aliphatic hydrocarbons such as pentane, hexane and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, benzene, toluene, xylene, hexylbenzene, hebutylbenzene, octylbenzene, nonylbenzene, decylbenzene, Halogenation of aromatic hydrocarbons such as benzenes having a long chain alkyl group such as undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene, etc., methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, etc. Hydrogen, can be used by blending a surfactant or the like alone or a mixture thereof such as carboxylic acid salts, or various other oils.

The electrophoretic particles 6 are organic or inorganic particles (polymer or colloid) having a property of moving by electrophoresis due to a potential difference in a dispersion medium. For example, one or more of white pigments such as titanium dioxide, zinc white, and antimony trioxide can be used. Furthermore, these pigments include, as necessary, charge control agents composed of particles of electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, compounds, titanium-based coupling agents, aluminum-based coupling agents. A dispersant such as a silane coupling agent, a lubricant, a stabilizer, and the like can be added.
The combination of the dispersion medium 5 and the electrophoretic particles 6 is not particularly limited, but the specific gravity of the dispersion medium 5 and the specific gravity of the electrophoretic particles 6 are set to be approximately equal to avoid sedimentation of the electrophoretic particles 6 due to gravity. It is preferable.

  FIG. 2 shows a plurality of pixel portions 17 (pixel electrodes 7a, TFT elements 7b), data lines 70a, scanning lines 71a, and the like arranged in a matrix constituting the image display area of the electrophoretic display device of this embodiment. It is a top view. In the electrophoretic display device of the present embodiment, a plurality of display units arranged in a matrix that forms an image display area are provided with a pixel electrode 7a as a transparent conductive layer and energization control for the pixel electrode 7a. TFT elements 7b are respectively formed, and a data line 70a to which an image signal is supplied is electrically connected to the source of the TFT element 7b. The image signal written to the data line 70a is supplied line-sequentially or is supplied for each group to a plurality of adjacent data lines 70a.

  Further, the scanning line 71a is electrically connected to the gate of the TFT element 7b, and scanning signals are supplied to the plurality of scanning lines 71a in a pulse-sequential manner at a predetermined timing. The pixel electrode 7a is electrically connected to the drain of the TFT element 7b, and the image signal supplied from the data line 70a is written at a predetermined timing by turning on the TFT element 7b for a certain period. An image signal of a predetermined level written in the pixel electrode 7a is held for a certain period with the common electrode 2. The charged particles having an electric charge are attracted toward the electrode of the opposite polarity to the charged particles of the pixel electrode 7a and the common electrode 2, and gradation display is made possible by comparing the color of the charged particles with the color of the dispersion medium.

  As shown in FIG. 2, a plurality of pixel electrodes 7a are provided in a matrix on the element substrate, and data lines 70a and scanning lines 71a are provided along vertical and horizontal boundaries of the pixel electrodes 7a. In the present embodiment, the display area formed in the area surrounded by the data line 70a and the scanning line 71a is a display unit (dot), and display can be performed for each display unit arranged in a matrix. It has a structure.

  As shown in FIG. 2, the colored layer 4 has a configuration in which a plurality of colored portions (color elements) 4R, 4G, 4B are arranged in a matrix in a plan view, and these colored portions 4R, 4G, 4B Each has a hue of red, green and blue. The colored portions 4R, 4G, and 4B, the pixel portion 17 of the element portion 7 formed at a position facing each colored portion, and the electrophoretic layer 11 in a portion surrounded by the colored portion and the pixel portion 17. In addition, one pixel of the electrophoretic display device 10 of the present embodiment is formed. That is, the electrophoretic display device 10 of the present embodiment can perform full color display, and each pixel can display one color of primary colors (RGB). The common electrode 2 is made of a transparent conductive material such as ITO (indium tin oxide).

  In the electrophoretic display device 10 having the above configuration, the electrophoretic particles 6 of the electrophoretic layer 11 are formed by forming an electric field between the pixel electrode 7a on the second substrate 8 side and the common electrode 2 on the first substrate 1 side. The gradation display according to the data signal supplied to the pixel electrode 7a is performed. That is, in the electrophoretic display device 10 of this embodiment, how the electrophoretic particles 6 are distributed in the thickness direction of the electrophoretic layer 11 can be controlled by the electric field strength applied to the electrophoretic layer 11. Therefore, the absorptance of light reflected by the electrophoretic particles 6 can be adjusted, and as a result, the intensity of light reaching the observer can be changed.

  As described above, in the electrophoretic display device 10 according to the present embodiment, since the colored layer 4 is provided between the first substrate 1 and the second substrate 8 that are arranged to face each other, a clear color display is possible. In addition, since it is not necessary to provide a separate color filter, it can be manufactured at low cost.

(Second Embodiment)
Next, an electrophoretic display device according to a second embodiment of the present invention will be described below with reference to FIGS. 3 is a cross-sectional configuration diagram of the electrophoretic display device 20 of the present embodiment, and FIG. 4 is a partial plan view of the electrophoretic display device shown in FIG. FIG. 3 shows a cross-sectional structure taken along line AA ′ shown in FIG.
The electrophoretic display device 20 is configured to include an electrophoretic layer (electro-optical layer) 21 between a first substrate 21 and a second substrate 28 that are arranged to face each other, and an inner surface of the first substrate 21. The colored layer 24 and the common electrode 22 are sequentially formed on the side (electrophoretic layer 31 side), and a plurality of pixel electrodes 7 a and the like are provided on the inner surface side (electrophoretic layer 31 side) of the second substrate 28. An element portion 7 is formed. On the first substrate 21 side, the first substrate 21, the colored layer 24, and the common electrode 22 have translucency, and the outer surface of the first substrate 21 is a display surface of the electrophoretic device 20.

  The first substrate 21 and the second substrate 28 can have the same configuration as the first substrate 1 and the second substrate 8 in the first embodiment shown in FIG. The common electrode 22 formed on the inner surface side of the first substrate 21 is made of a transparent conductive material such as ITO, and the element portion 7 formed on the inner surface side of the second substrate 28 is the element shown in FIG. The configuration is the same as that of the unit. In the present embodiment, the common electrode 22 is arranged on the colored layer 24 side. However, the element unit 7 may be arranged between the colored layer 24 and the first substrate 21, In that case, the pixel electrode 7a of the element portion 7 may be formed of a transparent conductive material such as ITO.

The electrophoretic layer 31 according to this embodiment includes a colored layer 4 formed on the first substrate 21 side, and a lattice shape in plan view formed with a certain height in the thickness direction of the electrophoretic display device 20. The partition medium 27 is provided, and the dispersion medium 25 and the electrophoretic particles 26 are sealed in the respective regions partitioned by the partition wall 27. A region partitioned by the partition wall 27 is a divided cell C, and in the electrophoretic display device 20 of this embodiment, the divided cell C constitutes each pixel. With such a configuration, the electrophoretic particles 26 dispersed in the dispersion medium 25 have their migratable regions limited to the inside of the divided cells C, and the particles in the electrophoretic layer 31. Can be effectively prevented from being unevenly distributed, or a plurality of particles can be aggregated to form a large aggregate, and as a result, the quality of the displayed image can be improved.
In the present embodiment, one divided cell C and one pixel correspond to each other, but a plurality of coloring portions and pixel portions 17 may be arranged in one divided cell C.

  Also in the electrophoretic display device according to the present embodiment, as shown in FIG. 4, a plurality of pixel electrodes 7 a are provided in a matrix on the element substrate, and data along the vertical and horizontal boundaries of the pixel electrodes 7 a, respectively. A line 70a and a scanning line 71a are provided. In the present embodiment, the display area formed in the area surrounded by the data line 70a and the scanning line 71a is a display unit (dot), and display can be performed for each display unit arranged in a matrix. It has a structure.

  Further, as indicated by the hatched portion in FIG. 4, the partition wall 27 is formed so as to overlap the data line 70a, the scanning line 71a, and the TFT element 7b which are wirings in a plane. Further, as shown in FIG. 3, the partition wall 27 is configured to display the display unit of each color formed corresponding to each color of red (R), green (G), and blue (B) of the color filter. 7a is formed.

The dispersion medium 25 of the electrophoretic layer 31 according to the present embodiment is colored with a coloring material containing a dye, and the colored layer 24 is colored with the same coloring material, so that both of the above are substantially satisfied. Same color. The configuration of the electrophoretic layer 31 will be described in detail below with reference to FIG. FIG. 5 is an enlarged cross-sectional configuration diagram illustrating the electrophoretic layer 31 illustrated in FIG. 3.
The electrophoretic layer 31 shown in FIG. 5 is configured such that the colored layer 24 disposed on the upper side of the drawing is immersed in the dispersion medium 25, and the electrophoretic particles 26 and the coloring material 30 are dispersed in the dispersion medium 25. Has been. The colored layer 24 is a porous body having a large number of pores 24a, and the dispersion medium 25 and the coloring material 30 are dispersed into the colored layer 24 through these pores 24a, and the colored layer 24 is colored. ing. The pore diameter of the pores 24a is smaller than that of the electrophoretic particles 26. The electrophoretic particles 26 do not enter the colored layer 24, which is a porous body, and the dispersion medium in the divided cells. Only within 25 can be electrophoresed.
As the electrophoretic particles 26, for example, white pigments such as titanium dioxide, zinc white, and antimony trioxide can be used.

As a porous material constituting the colored layer 24, for example, porous glass can be used. This porous glass can be produced by the following production method. First, NaO—B ₂ O ₃ —SiO ₂ glass is produced from raw materials SiO (silica sand), H ₃ BO ₃ (boric acid), and Na ₂ CO ₃ (soda ash) by an ordinary melting process, and this is molded. Then, when heat treatment is performed at several hundred degrees Celsius, the SiO ₂ rich phase and the Na ₂ O—B ₂ O ₃ rich phase in the glass undergo phase separation by spinodal decomposition at a scale of several nm. When this phase separation glass is immersed in an acid solution, only the NaO—B ₂ O ₃ phase is eluted with an acid, and a porous glass having a SiO ₂ skeleton is obtained. The porous glass obtained by this method has through pores connected from the surface to the inside, and has a structure in which the dye is easily penetrated into the inside when used in the colored layer 24. The pore diameter of the porous glass can be easily controlled by the heat treatment conditions.
In addition, as other porous materials, porous silicon, porous ceramics, a porous gel by a sol-gel method, and the like can also be applied. Since these porous materials contain an inorganic substance as a main component, they are hardly deteriorated by ultraviolet rays, can be obtained with excellent weather resistance, and can be made to have a long-life electrophoretic display device.
Further, there is an advantage that the material coloring the colored layer 24 is supplemented by the coloring material in the dispersion medium 25.
As the porous material constituting the colored layer 24, any of those listed above can be suitably used, but the refractive index is preferably the same as or close to the refractive index of the dispersion medium 25. . By making the refractive indexes of the two substantially the same, it is possible to reduce scattering due to the difference in refractive index and to display with high contrast and good color purity.

  In the above, the case where the colored layer 24 is made of a porous material has been described. However, as the colored layer applied to the electrophoretic display device according to the present invention, the dyeability that is easily colored by the penetration of the dye. Any material can be applied without any problem. FIG. 6 is a cross-sectional configuration diagram of an electrophoretic layer 31 having a colored layer 34 using such a dyeable material. As shown in this figure, the colored layer 34 is made of a dyeable material, and in this case, the colored layer 34 is colored in substantially the same color as the dispersion medium 25 by the coloring material contained in the dispersion medium 25. Is done. Examples of such dyeable materials include dyed resists and polyimide resins obtained by adding dichromate to water-soluble polymer materials such as gelatin and casein. It should be noted that when the colored layer 34 is formed using these dyeable materials, it is of course preferable that the electrophoretic particles 26 do not enter the colored layer 34.

Further, the colored layers 24 and 32 according to the present embodiment may have conductivity. With such a configuration, the electrophoretic layer 31 that can be driven at a low voltage can be obtained. This configuration will be described below with reference to FIG. FIG. 7 is a cross-sectional configuration diagram of an electrophoretic layer including a colored layer 44 having conductivity. FIG. 7 also shows a circuit diagram of the electrophoretic layer 31.
Since the electrodes for driving the electrophoretic particles 26 are arranged outside (upper and lower sides in the drawing) of the electrophoretic layer 31, if the colored layer 44 does not have conductivity, the electrophoretic layer 31 includes The capacitance C1 in the region including the electrophoretic particles 26 and the capacitance C2 of the colored layer 44 are formed. In this configuration, the colored layer 44 has conductivity, so that the colored layer 44 is It is shown as a resistor R and constitutes a path that bypasses the capacitor C2. Therefore, the capacity of the electrophoretic layer 31 can be substantially reduced, and the electrophoretic particles 26 can be driven at a low voltage.

  Further, in the electrophoretic layer 31 according to the present invention, as shown in the cross-sectional configuration diagram of the figure, the inside of the divided cell is divided into two regions by a semipermeable membrane 53, and only on one side (lower region in the drawing). When the electrophoretic particles 26 are present, the side where the electrophoretic particles 26 do not exist (the upper region in the drawing) can be used as the colored layer 54. The semipermeable membrane 53 is not limited to its constituent material as long as it has a structure that allows the dispersion medium 25 and the coloring material 30 to pass therethrough and does not transmit the electrophoretic particles 26 and has translucency. For example, a polyimide material, a silicone material, or the like can be applied.

  As described above, the electrophoretic display device according to the present embodiment has a colored layer in the electrophoretic layer 31 in any of the configurations shown in FIGS. 5 to 8 and is clear even if a separate color filter is not provided. Color display can be performed. Therefore, according to the present invention, it is possible to provide an electrophoretic display device that is low in cost and excellent in display quality.

Also in the electrophoretic display device 20 of the present embodiment having the above-described configuration, gradation display can be performed for each divided cell C. The principle of the light modulation will be described below.
First, the incident light I is decomposed into the intensity (IR, IG, IB) of the wavelengths of the three primary colors. This is represented by the following formula (Formula 1).

  (Formula 1) I = IR + IG + IB

  The full color is a control of three colors, but here, the divided cell C having the single color coloring portion 24R will be described. If colors other than red are absorbed by the colored portion 24R, the reflected brightness (Irefon) at the time of bright display (ON) is the red transmittance (Tfr) of the colored portion 24R and the reflectance (Rr) of the electrophoretic particles. It is given by the product, and becomes (Equation 2) below. In (Equation 2), Ir is the incident light intensity.

(Formula 2) Irefon = Ir · Tfr ² · Rr

  The reflected lightness (Irefoff) at the time of dark display (OFF) is determined by the product of the reflectance of each component and the transmittance per unit length of the solvent (Tr) and the optical path length (Lr). )become that way.

(Formula 3) Irefoff = Ir · Tfr ² · Tr ² · Lr ² · Rr

  FIG. 9 shows the relationship between the brightness and contrast with respect to the cell thickness obtained by the above equation. In addition, Table 1 shows the numerical values of the points described in the graph shown in FIG. The brightness and contrast shown in these figures and tables are values when the transmittance of the colored portion 4R and the transmittance of the dispersion medium 5 are both 90% per 1 μm. In the electrophoretic display device shown in FIG. 3, the state in which the electrophoretic particles 26 are in contact with the inner surface of the colored layer 24 (the state in which most electrophoretic particles have moved to the observer side) corresponds to the case where the cell thickness is 1 μm. The reflected brightness is 81%. If most of the electrophoretic particles 6 move to the element portion 7 side, for example, corresponds to a cell thickness of 20 μm, the reflected brightness corresponds to the reflected brightness of the dispersion medium 5 and is 1.5%. Therefore, in the electrophoretic display device under this condition, a contrast of about 55 can be obtained.

(Third embodiment)
In the second embodiment, the partition 27 is provided in the electrophoretic layer 31 to limit the migration range of the electrophoretic particles 26 in the electrophoretic layer 31 and improve the distribution uniformity of the electrophoretic particles 26. However, the microcapsule 60 shown in FIG. 10 can be used as the divided cell C shown in FIG. FIG. 10 is a cross-sectional configuration diagram of a microcapsule applicable to the electrophoretic layer according to the present invention. The capsule membranes 61 and 62 have a double structure, and the dispersion medium 25 filled in the space in the inner membrane 62 and The electrophoretic particles 25 are provided. The dispersion medium 25 includes a coloring material as in the previous embodiment.
The double-layer capsule films 61 and 62 have a protective film on the outer film 61. Transparent natural polymers such as gelatin and gum arabic, carboxymethylcellulose / ethylcellulose, polyvinyl alcohol / nylon / polyurethane / polyester / epoxy -It can be formed of a material such as a synthetic polymer such as melamine-formalin. The inner coating 62 is made of a dyeable material similar to that of the colored layer 34 shown in FIG. The coating 62 is colored with a coloring material contained in the dispersion medium 25 filled inside. Therefore, by arranging the microcapsules 60 in a matrix on the pixel electrodes 7a of the element section 7 shown in FIG. 3, the same operation as the electrophoretic layer 31 partitioned by the partition walls 27 shown in FIG. 3 is performed. Is possible.

  Also in the electrophoretic display device having the microcapsules of this embodiment, the coating 62 formed on the microcapsule 60 shown in FIG. 10 functions as a colored layer, so that clear color display is possible without providing a separate color filter. Thus, a color electrophoretic display device can be provided at low cost.

(Method for manufacturing electrophoretic display device)
Next, as an embodiment of the method for manufacturing an electro-optical device according to the present invention, a method for manufacturing the electrophoretic display device shown in FIG. 3 will be described below with reference to FIG. 11A to 11D are cross-sectional process diagrams illustrating a manufacturing process by the manufacturing method according to the present invention. In the present embodiment, an electrophoretic layer (electro-optical layer) manufacturing process which is a feature of the manufacturing method of the present invention will be described in detail.

  To manufacture the electrophoretic display device shown in FIG. 3 by the manufacturing method according to the present invention, first, a common electrode (not shown) is formed on the first substrate 21. Then, as shown in FIG. 11A, a colored layer 24 including colored portions 24R, 24G, and 24B and a partition wall 24M that partitions these colored portions is formed on the common electrode. The partition wall 24M is used as a base end portion of a partition wall 27 to be described later, and can be formed of the same material as the partition wall 27 to be described later. The colored layer 24 can be formed using a known color filter forming technique. A dye can also be used for coloring the colored layer 24.

  Next, as shown in FIG. 11B, the partition wall 27 is formed at a predetermined height along the partition wall 24M. The height of the partition wall 27 defines the cell gap of the electrophoretic display device, and is formed to a height of about 5 to 50 μm. In order to form the partition wall 27, a resin material that can be cured by UV curing, heat curing, condensation curing, or addition polymerization curing is used, and the material is gradually deposited on the partition wall 24M by an inkjet unit or the like. It can be formed by curing after forming to a predetermined height.

  Next, as shown in FIG. 11C, the dispersion medium 25, the electrophoretic particles 26, and the like are filled in a region (corresponding to the divided cell C in FIG. 3) partitioned by the partition walls 27. Here, the dispersion medium 25 to be filled may contain a coloring material or may not contain a coloring material. In the case of filling the dispersion medium 25 not containing the coloring material, the coloring medium 24 is impregnated with a high-concentration dye in advance in the formation step of the colored layer 24, and the dispersion medium 25 is not dried. Is filled, the dye of the colored layer 24 is leached into the dispersion medium 25 and the dispersion medium 25 is colored.

  Next, as shown in FIG. 11D, an electrophoretic layer according to the present invention can be obtained by forming a sealing material 32 at the upper end of the region filled with the dispersion medium 25 and the electrophoretic particles 26. The sealing material 32 can be made of a conductive material such as a resin material mixed with carbon or metal fibers. In this case, the sealing material 32 can be used as a common electrode. Therefore, the cost can be reduced by using the common member, and the electrophoretic display device can be reduced in weight and thickness at the same time. When the sealing material 32 is used as a common electrode, it is not necessary to form the common electrode on the substrate 21 before forming the colored layer shown in FIG. 11A. Alternatively, the sealing material 32 may be formed of an insulating material, and conductivity may be imparted to the sealing material 32 by performing ion implantation into the sealing material 32 after sealing.

(Other forms of manufacturing method of electrophoretic display device)
In the above, the case where the colored layer 24 is formed using the conventional color filter forming process has been described. However, in the electrophoretic display device according to the present invention, the colored layer 24 is formed of a porous material and used as a dispersion medium. The colored layer can be colored by impregnating the colored layer 24 with the coloring material contained therein. This manufacturing method will be described with reference to FIG.
First, as shown in FIG. 12A, a plurality of porous portions 24b and a partition wall 24M that partitions these porous portions 24b at a predetermined interval are formed on a substrate 21 such as glass or a resin film. As described above, the porous portion 24b can be formed of porous glass, porous silicon, or the like, and the partition wall 24M can be formed of a resin material or the like.

  Next, as shown in FIG. 12B, a partition wall 27 is formed on the partition wall 24M at a predetermined height. The method for forming the partition wall 27 may be the same as the manufacturing method described above. Next, as shown in FIG. 12C, each region (divided cell C) partitioned by the partition walls 27 is filled with the dispersion medium 25 and the electrophoretic particles 26. In this step, the dispersion medium 25 filled with a coloring material is used, and the colored layer 24 is formed by coloring the porous portion 24b to a predetermined color with the coloring material in the dispersion medium 25. FIG. 13 shows a process diagram when the inkjet unit method is applied to this process. As shown in FIG. 13, the inkjet units 71 to 73 store solutions containing the dispersion medium 25 mixed with coloring materials corresponding to R, G, and B, respectively. When the droplet 70 is dropped into each region partitioned by the partition wall 27, the porous portion 24b is colored by the coloring material contained in the droplet 70, and the colored portions 24R, 24G, and 24B of each color are sequentially formed. In this way, since coloring is performed by filling the dispersion medium 25 instead of forming a colored layer colored in advance, it is possible to easily cope with a change in the hue of the colored layer 24, The degree of manufacturing freedom can be increased. Moreover, since the colored layer 24 can be formed only by dropping the dispersion medium 25, the process is simplified, the manufacturing cost can be reduced, and the yield can be expected to be improved.

Next, as shown in FIG. 12D, the electrophoretic layer according to the present invention is obtained by sealing the region filled with the dispersion medium 25 and the electrophoretic particles 26 with a sealing material 32.
In the manufacturing method of the present embodiment, only the formation process of the electrophoretic layer including the colored layer 24 has been described. However, there is no particular limitation on the manufacturing method of other constituent members, for example, the element portion 7, and conventionally known methods are also used. It is also possible to apply the switching element manufacturing method.

  In the present embodiment, the case where the partition wall 27 is formed after the porous portion 24b is formed has been described. However, the partition wall 27 is formed on the substrate 21 first, and the substrate 21 partitioned by the partition wall 27 is formed. You may form the porous part 24b by apply | coating a porous material or dripping with an inkjet unit etc. FIG.

(Electronics)
The electro-optical device of the present invention is applied to various electronic apparatuses including a display unit. Hereinafter, application examples of the electronic apparatus including the electrophoretic display device of the above-described embodiment will be described.

1. Mobile Computer An example in which the electrophoretic display device of the present invention is applied to a mobile (portable) personal computer will be described. FIG. 14 is a perspective view showing the configuration of the personal computer. The personal computer 1200 includes the electrophoretic display device of the present invention as a display unit 1201. The personal computer 1200 includes a main body 1202 having a keyboard 1203.

2. Mobile Phone An example in which the electrophoretic display device of the present invention is applied to a mobile phone will be described. FIG. 15 is a perspective view showing the configuration of this mobile phone. The mobile phone 1300 includes the electrophoretic display device of the present invention as a small-sized display portion 1301. A cellular phone 1300 includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304.

3. Electronic Paper An example in which the electrophoretic display device of the present invention is applied to flexible electronic paper will be described. FIG. 16 is a perspective view showing the configuration of this electronic paper. The electronic paper 1400 includes the electrophoretic display device of the present invention as a display unit 1401. The electronic paper 1400 includes a main body 1402 made of a rewritable sheet having the same texture and flexibility as conventional paper.
FIG. 17 is a perspective view showing the configuration of an electronic notebook. The electronic notebook 1500 is a bundle of a plurality of electronic papers 1400 shown in FIG. The cover 1501 includes display data input means (not shown) that inputs display data sent from an external device, for example. Thereby, according to the display data, the display content can be changed or updated while the electronic paper is bundled.

  In addition to the above-described examples, other examples include a liquid crystal television, a viewfinder type and a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a videophone, and a POS terminal. And a device equipped with a touch panel. The electro-optical device according to the present invention can also be applied as a display unit of such an electronic apparatus.

  As described above in detail, the electro-optical device according to the present invention includes a first substrate, a second substrate facing the first substrate, the first substrate, and the second substrate. An electro-optical layer having electrophoretic particles and a dispersion medium, and a colored layer provided corresponding to the electro-optical layer and including at least one color element, The dispersion medium is at least partially colored in substantially the same color as the one color, so that a clear color display is possible and the electro-optical device is low in cost.

  DESCRIPTION OF SYMBOLS 1,21 ... 1st board | substrate, 8, 28 ... 2nd board | substrate, 2,22 ... Common electrode, 4, 24, 34, 44, 54 ... Colored layer, 5,25 ... Dispersion medium, 6,26 ... Electrophoretic particle , 7 ... element part, 17 ... pixel part, 27 ... partition, 60 ... microcapsule.

Claims (5)

A first substrate;
A second substrate facing the first substrate;
An electro-optic layer disposed between the first substrate and the second substrate and having a plurality of capsules containing electrophoretic particles and a dispersion medium;
A colored layer disposed on the electro-optic layer side of the first substrate and having a plurality of colored portions exhibiting different color tones;
A common electrode disposed on the electro-optic layer side of the first substrate;
A pixel electrode disposed on the electro-optic layer side of the second substrate;
With
The colored layer has a partition wall disposed between the colored portion exhibiting one color tone and the colored portion exhibiting another color tone,
The plurality of capsules are arranged in a region overlapping the plurality of colored portions and the partition wall in plan view, and the dispersion medium accommodated in the plurality of capsules has a color tone corresponding to any of the plurality of colored portions. An electro-optical device comprising:   The electro-optical device according to claim 1, wherein the electrophoretic particles include white particles. A plurality of the pixel electrodes are disposed on the electro-optic layer side of the second substrate,
3. The electro-optical device according to claim 1, wherein each of the pixel electrodes is disposed at a position corresponding to one of the plurality of colored portions in a plan view. The common electrode and the colored layer is provided between the electro-optical layer, the colored layer is an electro-optical device according to any one of claims 1 to 3, characterized in that a conductive . An electronic apparatus comprising a display unit an electro-optical device according to any one of claims 1 to 4.

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