JP2007004077A - Electrophoretic display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophoretic display element which permits a bright and clear color display. <P>SOLUTION: The electrophoretic display element is provided with a liquid layer containing migrating particles 6 and a dispersion medium 7 between a first electrode 1 and a second electrode 2, and, further, comprises a metal layer 101 made of metal thin film which doubles as the first electrode 1 and a coloring layer 14 made of a coloring insulation layer 9 and a metal fine particle layer 8, wherein a color display is performed by the use of the coloring layer 14. The metal layer is made of either one of the first electrode and the second electrode, or is disposed separately from the first electrode and the second electrode. In regard to color of the coloring layer, the color tone is adjusted by changing the thickness of the coloring insulation layer. The metal fine particle layer is desirably made of Ag, Au, Cu or Pt. The coloring insulation layer is desirably made of an inorganic oxide. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophoretic display element that performs color display.

  In recent years, with the development of information devices such as personal computers and mobile devices and the enhancement of the network environment, display devices for information devices have been increasingly used not only in offices but also in homes and outdoors. Also, especially in offices, a huge amount of information obtained via information equipment is output once on paper, and then discarded after a while, and the consumption of paper continues to increase. Yes. At the same time, stress caused by being forced to look at a light-emitting display screen such as a liquid crystal display or CRT for a long time has been pointed out.

  In modern society, there is a demand for the spread of low power consumption display rewriting devices that prevent environmental destruction due to increased paper consumption, have little stress even when viewed for a long time, have good visibility, and have excellent portability. In recent years, research and development of new display devices such as electronic paper and paper-like display has been active. As the most typical display method, monochrome rewriting by electrophoresis is performed, and visibility such as paper by reflected light can be displayed. For example, when an electrophoretic display element having a memory property disclosed in Patent Document 1 is used, it can be used outdoors for a long time with low power consumption.

  However, in the electrophoretic method, in general, when color filters such as red, green, and blue (RGB) are stacked in order to perform color display, there is a problem that utilization efficiency of reflected light is low and bright color display is difficult. In addition, there is a method of displaying using color migrating particles, but generally dyes and pigments are not sufficiently light-resistant, and for example, they may fade when used outdoors exposed to direct sunlight for a long time. In addition, there is a method of performing a desired color display by coloring the solvent liquid, but in this case also, the dye in the solvent may permeate into the resin particles and the contrast may be lowered.

Reduces paper output from information equipment, has a reflective type that can be viewed for a long time without stress, realizes low power consumption that can be rewritten by low-voltage drive, and has memory characteristics. There is a need for color display technology with good color that does not fade even when used outdoors for hours.
Japanese Patent No. 3421494

  As described above, in order to perform color display in an electrophoretic display element, a method of arranging a color filter layer such as RGB colored with a pigment or dye in a pixel is widely used. In order to perform bright color display, there has been a problem that adjustment such as thinning of the color filter must be made in order to avoid significantly impairing the utilization efficiency of reflected light.

  For example, a liquid crystal display mounted on a normal personal computer (PC) is almost a transmissive type using a backlight, and the light emitted from the backlight is incident on the human eye only once through the color filter. The In this method, in order to improve color reproducibility, the concentration of pigments and dyes in the color filter is increased or the light transmittance caused by increasing the film thickness is reduced by increasing the light intensity of the backlight. In addition, it is possible to achieve both color reproducibility and brightness in color display.

  On the other hand, in a reflective display, ambient light is once reflected through the color filter after being transmitted through the color filter, and is transmitted through the color filter again to enter the human eye. A decrease in light utilization due to passing through the color filter is inevitable. For this reason, the light utilization efficiency is low, and bright color display is difficult. This shortage of light can be resolved by reducing the color pigment concentration of each pixel of the color filter, but the decrease in the color density of the color filter results in a change in the hue of the color filter. The color reproducibility of is reduced.

  Therefore, the present invention prevents the loss of external light caused by passing through the conventional color filter twice in a reflective display by providing a colored layer that is completely different from the color filter using conventional pigments and dyes. An object of the present invention is to provide an electrophoretic display element capable of vivid color display.

  That is, the present invention provides an electrophoretic display device having a liquid layer composed of electrophoretic particles and a dispersion medium between a first electrode and a second electrode, and includes a metal layer made of a metal thin film, a coloring insulating layer, and a metal microparticle layer. An electrophoretic display element having a colored layer.

  The present invention also provides an electrophoretic display element comprising a liquid layer composed of electrophoretic particles and a dispersion medium between a first electrode and a second electrode, wherein a metal is disposed at either one of the first electrode and the second electrode. An electrophoretic display element having a metal layer made of a thin film, a colored layer made of a coloring insulating layer, and a metal fine particle layer, and performing color display by the colored layer.

It is preferable that the metal layer is formed of one of the first electrode and the second electrode, or is provided separately from the first electrode and the second electrode.
It is preferable that the first electrode and the second electrode are connected to each other through a resistance layer, and has a means for generating a potential gradient in the resistance layer.

The color of the colored layer is preferably adjusted by changing the thickness of the coloring insulating layer.
The metal fine particle layer is preferably made of at least one of Ag, Au, Cu, and Pt.

The coloring insulating layer is preferably an inorganic oxide.
The present invention also includes a first substrate, a second substrate, a partition supporting these substrates, a liquid layer composed of electrophoretic particles and a dispersion medium disposed in a sealed space formed by the substrate and the partition, In an electrophoretic display element including a first electrode provided on one substrate and a second electrode provided on at least a part of the partition, a metal layer formed of a metal thin film at a position of the first electrode, a coloring insulating layer, and An electrophoretic display element having a colored layer composed of a fine metal particle layer and a scattering layer provided on a second substrate.

  The present invention also includes a first substrate, a second substrate, a partition supporting these substrates, a liquid layer composed of electrophoretic particles and a dispersion medium disposed in a sealed space formed by the substrate and the partition, In an electrophoretic display element comprising a first electrode formed on one substrate and a second electrode formed to constitute at least a part of the inside or side of the partition wall, a metal thin film is formed at the position of the first electrode. The electrophoretic display element is characterized by having a colored layer composed of a metal layer, a coloring insulating layer and a metal fine particle layer, and the colored layer diffusely reflects.

  The present invention relates to an electrophoretic display device comprising a liquid layer containing electrophoretic particles and a dispersion medium charged between a first electrode and a second electrode, wherein a metal layer made of a metal thin film, an insulating layer for coloring, and a metal microparticle layer By providing a colored layer consisting of three types of adjacent layers, the bottom of the pixel is colored in a completely different way from the conventional color filter, and the loss of external light caused by passing through the conventional color filter twice on a reflective display Can be prevented and bright color display can be performed.

The present invention is described in detail below.
The electrophoretic display element of the present invention includes a dispersion layer in which each pixel is sandwiched between two substrates, and the dispersion layer contains a colorless liquid and black electrophoretic particles. The present invention is characterized in that each pixel has a colored layer comprising three layers of a metal layer, a coloring insulating layer formed thereon, and a metal fine particle layer formed thereon.

The colored layer in the present invention will be described.
In recent years, nanotechnology has been actively promoted, and changes in physical properties due to the nano-size of fine particles have attracted attention. Among them, metal fine particles usually show metallic luster in the bulk, that is, in a state of being a lump of a certain size or having a certain thickness, but when they become nano-sized fine particles, they absorb electromagnetic waves of a specific wavelength. The phenomenon of coloring (plasmon absorption) is well known. (For example, see “What is Ultrafine Particles” written by Kiyoshi Kawamura (Maruzen)) This phenomenon has been used for coloring stained glass for a long time, and it has a clear color without turbidity due to absorption and transmission of natural light. It has been pointed out that it has excellent coloring properties and exhibits far higher coloring ability than pigments conventionally used in color filters.

  In general, light does not couple with an electron wave, but a special electron wave mode occurs on the dielectric surface. This is called surface plasmon, and its application to biosensors has recently been studied. For example, evanescent light having an electric field intensity 10 times or more that of the incident photoelectric field exists on the metal surface, and its application to Raman enhancement has been proposed.

  The color display in the electrophoretic display element of the present invention uses the coloring phenomenon due to the plasmon absorption inherent to the metal fine particles and the interaction by disposing on the metal layer and the dielectric layer, for example, reflecting light. Thus, a vivid color display is made possible. Specifically, a vivid color display is possible by providing a laminated structure in which an nano-sized metal fine particle layer, a dielectric layer, and a metal thin film that reflects light are sequentially laminated in the electrophoretic display element. It is to make.

Embodiments of the present invention will be described with reference to the drawings.
Example 1
A basic configuration of the present invention will be described with reference to FIG. FIG. 1 schematically shows a cross section of a typical configuration of a pixel in an electrophoretic display element of the present invention. A partition wall 10 including an electrode 2 and an insulating layer 5 is provided to keep the two substrates 3 and 4 at a predetermined interval and to separate adjacent pixels. The substrates 3 and 4 are made of a light transmissive material such as transparent glass or transparent film. Here, the substrate 3 is not necessarily transparent, and may be formed of a film substrate, a metal substrate, or the like.

For the insulating layer 5, for example, a resin such as polyimide or an inorganic oxide such as SiO ₂ is preferably used.
The dispersion medium 7 and the migrating particles 6 are held between the substrates, and are moved in the pixels by the electric field formed by the electrodes 1 and 2 to change the display state. This figure shows a state in which a voltage is applied between the electrode 1 and the electrode 2 so that the migrating particles 6 are brought close to the partition wall surface. In this state, the observer can observe the color of the bottom surface of the pixel. .
The insulating layer 5 here is for electrically blocking the migrating particles 6 and the electrode 2 when a potential is applied to the electrode 2.

  The present invention is characterized by having a metal layer 101 made of a metal thin film, a colored insulating layer 9 and a colored layer 14 made of a metal fine particle layer 8. The coloring in the present invention is a colored layer composed of three adjacent layers of the electrode 1 also serving as the metal layer 101, the coloring insulating layer 9 laminated on the electrode 1, and the metal fine particle layer 8 laminated thereon. 14 is expressed. Here, the electrode 1 serves both as an electrode for migrating particles and a metal layer for coloring. The coloring insulating layer 9 here is synonymous with an electromagnetic dielectric. Since the present invention relates to the element structure of the electric drive element, it will be referred to as a coloring insulating layer.

  The photometal layer 1 is not particularly limited as long as it acts to reflect light incident from the observer side, and as a result, the colored layer 14 exhibits a desired coloration. However, surface plasmon may be generated in the visible range. As a well-known metal group, precious metals and platinum groups are preferable. For example, Ag, Au, Cu, Pt, etc. are preferably used. The metal mirror is made of a metal thin film and preferably has a thickness of 50 nm or more in order to obtain a continuous film state. Furthermore, in order to obtain a state equivalent to that of a bulk metal, it is more preferable that the film thickness is 100 nm or more, preferably 100 to 300 nm.

The coloring insulating layer 9 is transparent and is not particularly limited as long as it exhibits a desired coloring in the above-described adjacent three-layer structure. However, the film thickness uniformity can be achieved by a vacuum film forming method such as a vapor deposition method or a sputtering method. In particular, inorganic oxides are preferably used because an excellent thin film can be formed. For _{example, SiO 2, TiO 2, Al} 2 O 3, NiO, ZnO, and mixtures thereof are preferred.

  Since the film thickness (9t in the figure) of the coloring insulating layer 9 greatly affects the color, it is preferable that the film thickness does not change due to heat or the like. The thickness 9t of the coloring insulating layer 9 varies depending on the desired color, but a film thickness of 10 to 300 nm is desirable. Furthermore, in order to obtain a clear coloring state, a film thickness of about 30 nm to 200 nm is preferable. As a film forming method that can easily control the film thickness on the order of nm as described above, a film forming method using a vacuum apparatus such as a sputtering method, a resistance heating vapor deposition method, or a CVD method can be cited. Any method that can be controlled is not particularly limited.

  The metal fine particle layer 8 formed on the coloring insulating layer 9 is preferably made of a metal that can be easily colored in the visible region by being finely divided. A noble metal such as Au, Ag, and Cu, and a platinum group such as Pt are particularly preferably used. Further, the metal fine particle layer 8 preferably has a film thickness of about 1 nm to 20 nm in which the entire film tends to exist in the form of fine particles. Furthermore, a small metal particle layer having a uniform film thickness of about 1 nm to 10 nm is easily formed and can be preferably selected. The particle diameter of the metal fine particles constituting the metal fine particle layer 8 is desirably in the range of an average particle diameter of 0.1 to 300 nm, preferably 1 to 100 nm.

  Examples of the method for forming the metal fine particle layer 8 include a film forming method using a vacuum apparatus such as a sputtering method, a resistance heating vapor deposition method, and a CVD method, as in the method for forming the coloring insulating layer. As long as the film thickness can be controlled as described later, there is no particular limitation.

The desired color can be varied as follows by changing the film thickness 9t of the coloring insulating layer 9.
For example, on a glass substrate, Ag is deposited as a metal layer by about 150 nm by a sputtering method, and SiO ₂ is deposited thereon by a sputtering method as a coloring insulating layer by about 170 nm as a coloring insulating layer. When an Ag fine particle film having an average particle diameter of is formed, a blue color is exhibited.

As another example, Ag is similarly laminated on a glass substrate by about 150 nm as a metal layer by sputtering, and SiO ₂ is laminated by about 200 nm by sputtering as an insulating layer thereon, and Ag is similarly formed thereon. When an Ag fine particle film having an average particle diameter of about 5 nm is formed by resistance heating vapor deposition, a green color is exhibited.

As yet another example, Ag is similarly deposited as a metal layer on a glass substrate by about 150 nm by sputtering, and SiO ₂ is laminated by about 250 nm as an insulating layer thereon, and resistance heating vapor deposition is further formed thereon. When an Ag fine particle film having an average particle diameter of about 5 nm is formed, a red color is exhibited.

  At this time, the color can be varied by changing the thickness of the metal material of the metal layer, the metal material of the metal fine particle layer, and the metal fine particle layer. When a different color is to be arranged for each pixel arranged in a large number in the electrophoretic display element, the process of the metal layer and the metal fine particle layer is performed in common, and the thickness of the coloring insulating layer is changed for each pixel by using a metal mask. The method for producing the display element by changing the method is preferable because the process is simple. In addition to the method using a metal mask, for example, when a plurality of RGB three colors are arranged in a display element, it can be manufactured by repeating the photolithography process three times and the above-described coloring insulating layer forming process. Is possible.

  Therefore, a metal layer that also serves as the electrode 1, for example, to reflect light, is provided on the substrate 1 having an insulating layer or a base layer (not shown) provided on the surface as appropriate, and a desired color is formed thereon. A corresponding color insulating layer 9 having a thickness of 9t can be laminated, and a metal fine particle layer 8 can be further laminated to color the pixel bottom surface.

  The partition wall 10 can be formed of a generally used resist material, thermoplastic material, ultraviolet curable material, or the like. The partition wall has a thickness of about 5 μm to 30 μm. An electrode 2 is formed on the surface of the partition wall and is made of a metal film such as Al or Ti, or ITO.

  Electrophoretic particles 6 dispersed in a dispersion medium 7 are enclosed in a sealed space formed between both the substrates 3 and 4 and the partition wall 10. As the dispersion medium, water, methanol, ethanol, acetone, hexane, toluene, aromatic hydrocarbons such as benzenes having a long-chain alkyl group, or other various oils alone or a mixture thereof, a surfactant, etc. Can be used.

  The migrating particles 6 are organic or inorganic particles having a property of moving by electrophoresis due to a potential difference in a dispersion medium. As the electrophoretic particles, for example, one or more of black pigments such as aniline black and carbon black, white pigments such as titanium dioxide and antimony trioxide, azo pigments, and other colored pigments can be used. .

  Furthermore, these pigments include, as necessary, charge control materials composed of particles of electrolytes, surfactants, resins, rubbers, oils, titanium-based coupling agents, aluminum-based coupling agents, silane-based coupling agents, Lubricants, stabilizers and the like can be added. Further, in the first embodiment, a drive voltage generator that generates a drive voltage (not shown) is connected between the first electrode 1 and the second electrode 2.

  After preparing the partition 10 provided with the electrode / metal layer 1, the coloring insulating layer 9, the metal fine particle layer 8, the electrode 2 and the insulating layer 5 as described above, the solution composition comprising the migrating particles 6 and the dispersion medium 7 is prepared. Is injected into the pixel, and then the substrate 4 is disposed on the upper surface and sealed.

  As a method of injecting the solution composition, the solution composition may be simply dropped on the substrate, but in order to increase the number of particles per pixel and to equalize the number of particles per pixel, the solution composition is dropped. In addition, it is effective to simultaneously perform a process such as applying an electric field that attracts the migrating particles to the electrode 1.

  Next, after the migrating particles and the dispersion medium are uniformly injected into the pixel, the substrate 4 is placed and sealed to prevent bubbles from entering. At this time, a flexible substrate such as a PET film or a PES film is preferably used as the substrate 4. When sealing, it is preferable to apply a little pressure from the end portion of the substrate to expel excess dispersion medium out of the display element. Further, the injection of the solution composition can be performed by dropping and applying the solution, but it can also be preferably performed for each pixel using an ink jet method.

  In this way, after the migrating particles and the dispersion medium are sealed in the pixel, the periphery of the display element is sealed to perform a process for preventing the outflow of the contents. The sealing method is not particularly limited. For example, the inner side of the substrate 4 (inside the pixel) and the upper part of the partition wall are covered with a photocurable resin, and after the solution is sealed, each pixel is hermetically sealed by light irradiation. Etc. can be preferably performed.

  In the electrophoretic display device manufactured as described above, when a voltage is applied between the electrode 1 and the electrode 2 to move the particles and the bottom surface of the pixel is covered with the migrating particles, black display or the migrating particles are used as the partition walls. When moved, operation of color display and intermediate gradation display can be performed.

Example 2
Next, another basic configuration of the present invention will be described with reference to FIG. FIG. 2 schematically shows a cross-section of a typical configuration of another electrophoretic display element of the present invention.

  Although Example 1 has a basic configuration, in practice, it is preferable to cover and protect the above-described colored layer composed of three adjacent layers with another insulating layer 5. Further, the insulating layer 5 for protection can be easily formed in a lump with the same material as that of the insulating layer 5 in FIG. 1 after forming a colored layer composed of three adjacent layers. Thereby, it is possible to prevent the deterioration of the metal fine particle layer 8, the deterioration of the migrating particles, and the like caused by repeating the display operation.

Example 3
Next, another configuration of the present invention will be described with reference to FIG. FIG. 3 schematically shows a cross-section of a typical configuration of another electrophoretic display element of the present invention. A forward scattering layer 11 is further provided on the substrate 4 of FIG. Thereby, vivid display without parallax can be realized with a relatively simple configuration. Further, the front scattering layer 11 can be formed by a method such as sticking on the upper surface of the sealed display element.

Example 4
Next, another configuration of the present invention will be described with reference to FIG. FIG. 4 schematically shows a cross section of a typical configuration in another electrophoretic display element of the present invention. A metal layer and electrode 1 necessary as a colored layer is formed on the substrate 3 of FIG. A coloring insulating layer 9 is formed thereon, and a metal fine particle layer 8 is further formed. Thereafter, the inside of the pixel is covered with the insulating layer 5 as in the second embodiment.

  The metal layer / electrode 1 is formed on the unevenness 13. The unevenness 13 can be formed, for example, by applying a photosensitive resin and then performing exposure and wet development. Alternatively, a method using fine unevenness on the glass of the base substrate may be used. With such a configuration, the metal layer constituting the colored layer can serve as the electrode 1 for causing electrophoresis and also have a function of diffusing light. Since the distribution of the inclination angle of the unevenness can be controlled, the viewing angle can be enlarged and the external light can be reflected efficiently, it is possible to realize a brighter and better display.

  Although the unevenness | corrugation 13 is not specifically limited, The height of an unevenness | corrugation is good to create in the range of about 0.5 micrometer-3 micrometers, for example. Moreover, it is good to produce the period of an unevenness | corrugation in the range of about 1 micrometer-10 micrometers. For example, the projections and depressions having a height of about 1 μm and a period of about 2.5 μm are preferably used. Actually, the selection is made so as not to hinder the movement of the migrating particles 6. The shape of the unevenness is in units of micrometers, whereas the coloring insulating layer 9 has a thickness that does not exceed 300 nm, so that color display can be performed in the same manner.

Example 5
Next, another configuration of the present invention will be described with reference to FIG. FIG. 5 schematically shows a cross-section of a typical configuration in the electrophoretic display element of the present invention. On the substrate 3 in FIG. 5, a laminated structure required for coloring similar to that in the second embodiment is formed.

  In Examples 1 to 4, the metal layer also serves as an electrode. However, in this example, the metal layer 101 is formed separately from the electrode 1. As in the previous embodiment, the coloring insulating layer 9 and the metal fine particle layer 8 are formed on the metal layer 101, and the insulating layer 5 is formed thereon. Further, an electrode 1 is formed thereon, and the resistance layer 12 is formed by connecting the electrode 1 and the electrode 2. As a result, a potential gradient is generated in the resistance layer when a driving voltage is applied, and the potential of the resistance layer becomes smaller as the electrode 2 is closer to the electrode 2 due to the resistance voltage division, and the electric field non-uniformity in the pixel is eliminated, and a stable halftone is obtained. An indication can be obtained. For this reason, the electrode 1 is preferably formed at the center of the pixel as shown in the figure.

For the resistance layer 12, diamond-like carbon (DLC), a polymer material in which conductive fine particles or a guidance filler are dispersed, and the like are preferably used.
In addition, the potential gradient effect of the resistive layer 12 includes the charged state of the electrophoretic solution, the physical and chemical state of the outermost surface of the resistive layer, the three-dimensional shape of the resistive layer itself, and the intended use of the display element (rewriting of the display image). The specific resistance value of the resistance layer 12 itself is not limited to this, but it is preferably used in the range of 10 ⁴ Ω · cm to 10 ¹⁴ Ω · cm. Furthermore, it is more preferably used in the range of 10 ⁶ Ω · cm to 10 ¹¹ Ω · cm.

Example 6
Next, another configuration of the present invention will be described with reference to FIG. FIG. 6 schematically shows a cross section of another typical configuration of the electrophoretic display element of the present invention. In the figure, the coloring insulating layer 9 and the metal fine particle layer 8 are laminated on the metal layer 101 as shown in the figure to give a desired coloring, and the metal layer 101 also serves as a diffuse reflector similarly to the fourth embodiment. . On the other hand, the bottom surface and the pixel wall surface of the pixel are resistance layers similar to those in the fifth embodiment, and the particles 6 in the pixel are driven by the electrodes 1 and 2.

  Thereby, as described above, bright coloration using metal fine particles, an increase in brightness due to diffuse reflection, and a reduction of residual DC generated during driving can be performed, and clearer color display rewriting can be performed.

Example 7
Next, another configuration of the present invention will be described with reference to FIG. FIG. 7 schematically shows a cross section of another typical configuration of the electrophoretic display element of the present invention. The metal layer 101, the coloring insulating layer 9 and the metal fine particle layer 8 are laminated adjacently as shown in the figure on the unevenness 13 formed on the substrate in the same manner as in Example 4 to give a desired color, and the metal layer Reference numeral 101 also serves as a diffusive reflector as in the fourth embodiment. On the other hand, the pixel bottom surface and the pixel wall surface are resistance layers similar to those in the fifth embodiment, and the driving of the particles 6 in the pixel is performed by the electrodes 1 and 2. At this time, the electrode 1 is connected to the metal layer 101 through a contact hole.

  Accordingly, as described above, bright coloring using metal fine particles, brightness increase by diffuse reflection, and reduction of residual DC generated during driving can be simultaneously performed, and clearer color display rewriting can be performed. At the same time, the power supply to the electrode 1 can be easily performed from the element backside wiring (not shown) via the metal layer 101.

  Since the electrophoretic display element of the present invention is provided with a color layer composed of a metal layer made of a metal thin film, a coloring insulating layer, and a metal fine particle layer adjacent to each other, the bottom surface of the pixel can be colored and color display can be performed. It is possible to perform vivid color display with little light loss.

It is a cross-sectional schematic diagram of one pixel of the electrophoretic display element according to Example 1 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 2 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 3 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 4 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 5 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 6 of the invention. It is a cross-sectional schematic diagram of one pixel of an electrophoretic display element according to Example 7 of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode 2 Electrode 3 Substrate 4 Substrate 5 Insulating layer 6 Electrophoretic particle 7 Dispersion medium 8 Metal fine particle layer 9 Coloring insulating layer 10 Partition 11 Forward scattering layer 12 Resistance layer 13 Concavity and convexity 14 Colored layer 15 Observer 101 Metal layer

Claims (9)

  In an electrophoretic display element having a liquid layer made of electrophoretic particles and a dispersion medium between the first electrode and the second electrode, the electrophoretic display element has a metal layer made of a metal thin film, a colored insulating layer and a colored layer made of a metal fine particle layer. An electrophoretic display element.   In the electrophoretic display element including a liquid layer composed of electrophoretic particles and a dispersion medium between the first electrode and the second electrode, a metal layer made of a metal thin film at one of the first electrode and the second electrode, The electrophoretic display element according to claim 1, further comprising a colored layer including a coloring insulating layer and a metal fine particle layer, wherein color display is performed by the colored layer.   3. The electrophoresis according to claim 1, wherein the metal layer includes one of the first electrode and the second electrode, or is provided separately from the first electrode and the second electrode. Display element.   4. The electrophoretic display element according to claim 1, further comprising means for connecting the first electrode and the second electrode via a resistance layer and generating a potential gradient in the resistance layer. 5.   The electrophoretic display element according to claim 1, wherein the color of the colored layer is adjusted by changing the thickness of the insulating layer for coloring.   The electrophoretic display element according to claim 1, wherein the metal fine particle layer is made of at least one of Ag, Au, Cu, and Pt.   The electrophoretic display element according to claim 1, wherein the coloring insulating layer is an inorganic oxide.   A first substrate, a second substrate, a partition supporting these substrates, a liquid layer composed of electrophoretic particles and a dispersion medium disposed in a sealed space formed by the substrate and the partition, and a first substrate. In an electrophoretic display device having a first electrode and a second electrode provided on at least a part of the partition wall, a color comprising a metal layer made of a metal thin film, a coloring insulating layer and a metal fine particle layer at the position of the first electrode. An electrophoretic display element having a layer and a scattering layer provided on a second substrate.   A first substrate, a second substrate, a partition supporting these substrates, a liquid layer composed of migrating particles and a dispersion medium disposed in a sealed space formed by the substrate and the partition, and formed on the first substrate. In an electrophoretic display device comprising a first electrode and a second electrode formed to constitute at least a part of the inside or side of the partition wall, a metal layer made of a metal thin film at the position of the first electrode, for coloring An electrophoretic display element comprising a colored layer comprising an insulating layer and a metal fine particle layer, and the colored layer diffusely reflects.

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