WO2016199617A1 - Dispositif d'affichage et appareil électronique - Google Patents

Dispositif d'affichage et appareil électronique Download PDF

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WO2016199617A1
WO2016199617A1 PCT/JP2016/065974 JP2016065974W WO2016199617A1 WO 2016199617 A1 WO2016199617 A1 WO 2016199617A1 JP 2016065974 W JP2016065974 W JP 2016065974W WO 2016199617 A1 WO2016199617 A1 WO 2016199617A1
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Prior art keywords
particles
display device
migrating particles
porous layer
display
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PCT/JP2016/065974
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English (en)
Japanese (ja)
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亮 加瀬川
小林　健
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ソニー株式会社
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Publication of WO2016199617A1 publication Critical patent/WO2016199617A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/1675—Constructional details
    • G02F1/1677—Structural association of cells with optical devices, e.g. reflectors or illuminating devices
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/37—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being movable elements

Definitions

  • the present disclosure relates to a display device and an electronic apparatus that perform image display using an electrophoresis phenomenon.
  • an electrophoretic display device that produces a contrast (contrast) using an electrophoretic phenomenon can be cited.
  • Various studies have been made on display methods of electrophoretic display devices. Specifically, a method has been proposed in which two types of charged particles having different optical reflection characteristics and polarities are dispersed in an insulating liquid, and each charged particle is moved using the difference in polarity. In this method, since the distribution of the two types of charged particles changes according to the electric field, contrast is generated using the difference in optical reflection characteristics.
  • the display since display is performed using the contrast of reflected light as described above, the display is basically monochrome (monochrome) display.
  • a pair of opposing substrates is displayed.
  • an image display device in which a layer having a gap is provided between the two, and two types of migrating particles having different colors and particle sizes are used.
  • the gap of the layer disposed between the pair of substrates is large enough to prevent one of the two types of migrating particles from entering, thereby enabling multicolor display.
  • a display device includes a plurality of types of migrating particles having different average particle sizes, and a plurality of porous layers that are formed of a fibrous structure and have different average pore sizes. is there.
  • An electronic apparatus includes the display device according to the embodiment of the present disclosure.
  • a plurality of types of migrating particles having different average particle diameters and a plurality of porous particles having a different average pore diameter from each other are formed by a fibrous structure.
  • the moving distance of the migrating particles is adjusted by the particle size of the migrating particles and the pore size of the porous layer.
  • migration is performed by using a plurality of types of migrating particles having different average particle sizes and a plurality of porous layers having different average pore sizes.
  • the moving distance of the particles was adjusted by the particle size of the migrating particles and the pore size of the porous layer.
  • the time required for display switching can be shortened. Therefore, it is possible to provide a display device and an electronic device that can perform multicolor display while improving display quality. Note that the effects described here are not necessarily limited, and may be any effects described in the present disclosure.
  • FIG. 2 is a schematic diagram for explaining the operation of the electrophoretic element shown in FIG. 1.
  • FIG. 2 is a schematic diagram for explaining the operation of the electrophoretic element shown in FIG. 1.
  • It is a conceptual diagram explaining the cyan display in the display apparatus shown in FIG. It is a characteristic view explaining the waveform of the applied voltage at the time of the cyan display shown to FIG. 5A. It is a conceptual diagram explaining the magenta display in the display apparatus shown in FIG. FIG.
  • 6B is a characteristic diagram illustrating a waveform of an applied voltage during magenta display illustrated in FIG. 6A. It is a conceptual diagram explaining the yellow display in the display apparatus shown in FIG. It is a characteristic view explaining the waveform of the applied voltage at the time of yellow display shown to FIG. 7A. It is a conceptual diagram explaining the yellow display in the display apparatus as a comparative example. It is a characteristic view explaining the waveform of the applied voltage at the time of yellow display shown to FIG. 8A. 14 is a cross-sectional view illustrating a configuration of a display device according to Modification 1 of the present disclosure. It is a schematic diagram explaining the white display in the display apparatus shown in FIG. It is a schematic diagram explaining the black display in the display apparatus shown in FIG.
  • FIG. 14 It is a schematic diagram explaining the red display in the display apparatus shown in FIG. 14 is a cross-sectional view illustrating a configuration of a display device according to Modification 2 of the present disclosure.
  • FIG. It is a figure showing the time change of the electric potential difference with respect to the display surface side of the back side of the display apparatus shown in FIG. It is a figure showing the time change of the average distribution position of each migrating particle by the time change of the electric potential difference shown in FIG. It is a figure showing the time change of the electric potential difference with respect to the display surface side of the back side of a general display apparatus. It is a figure showing the time change of the average distribution position of each migrating particle by the time change of the electric potential difference shown in FIG.
  • FIG. 16B is a perspective view illustrating another example of the electronic book illustrated in FIG. 16A. It is a perspective view showing the external appearance of the tablet personal computer using the display apparatus of this indication.
  • Embodiment display device having electrophoretic particles having a plurality of types of particle sizes and a porous layer having a plurality of types of pore sizes
  • Configuration of electrophoretic element 1-2.
  • Action / Effect Modification 1 Display device having a plurality of types of migrating particles and a plurality of types of porous layers each having a different charge amount
  • Configuration of electrophoretic element 2-2.
  • Modification 2 Display device in which a plurality of porous layers having light transmittance on the display surface side and different pore diameters are laminated
  • Action / effect 4 Application example (electronic equipment)
  • FIG. 1 illustrates a cross-sectional configuration of a display device (display device 1) according to an embodiment of the present disclosure.
  • FIG. 2 shows a planar configuration of the electrophoretic element 30 constituting the display device 1.
  • the display device 1 is applied to various electronic devices such as a display device that displays an image by using an electrophoretic phenomenon and displays an image, for example, an electronic paper display.
  • the display device 1 includes, for example, a display layer including an electrophoretic element 30 between a drive substrate 10 and a counter substrate 20 that are disposed to face each other with a spacer 35 interposed therebetween.
  • the electrophoretic element 30 includes an insulating liquid 31 including electrophoretic particles 32 and a porous layer 33 having a plurality of pores 333.
  • the porous layer 33 has a fibrous structure 331 and non-migrating particles 332 held by the fibrous structure 331.
  • 1 and 2 schematically show the configuration of the electrophoretic element 30 and may differ from actual dimensions and shapes.
  • the migrating particles 32 have a plurality of types of average particle sizes
  • the porous layer 33 has a configuration in which layers having a plurality of types of average pore sizes are stacked.
  • the insulating liquid 31 is, for example, one type or two or more types of non-aqueous solvents such as an organic solvent, and specifically includes paraffin or isoparaffin. It is preferable that the viscosity and refractive index of the insulating liquid 31 be as low as possible. This is because the mobility (response speed) of the migrating particles 32 is improved, and the energy (power consumption) required to move the migrating particles 32 is lowered accordingly. Further, the difference between the refractive index of the insulating liquid 31 and the refractive index of the porous layer 33 is increased, and the light reflectance of the porous layer 33 is increased. Note that a weak conductive liquid may be used instead of the insulating liquid 31.
  • the insulating liquid 31 may contain various materials as necessary. This material is, for example, a colorant, a charge control agent, a dispersion stabilizer, a viscosity modifier, a surfactant or a resin.
  • the electrophoretic particles 32 are one or more charged particles that are electrically movable, and are dispersed in the insulating liquid 31.
  • the migrating particles 32 in the present embodiment have a plurality of types of average particle diameters, and are composed of one or more charged particles for each average particle diameter.
  • the migrating particles 32 have the same number of types of average particle diameter as the number of porous layers 33 to be described later.
  • four types of migrating particles 32A and 32B having different average particle diameters are used. , 32C, 32D.
  • the migrating particles 32 also have arbitrary optical reflection characteristics (light reflectivity).
  • the light reflectance of the migrating particles 32 is not particularly limited, but is preferably set so that at least the migrating particles 32 can shield the porous layer 33. This is because contrast is generated by utilizing the difference between the light reflectance of the migrating particles 32 and the light reflectance of the porous layer 33.
  • the four types of migrating particles 32A, 32B, 32C, and 32D constituting the migrating particle 32 have different colors for each average particle diameter. Specifically, for example, it is colored cyan (electrophoretic particles 32A), magenta (electrophoretic particles 32B), yellow (electrophoretic particles 32C), and black (electrophoretic particles 32D).
  • the particle size of the migrating particles 32 is preferably in the range of, for example, 100 nm or more and 2 ⁇ m or less, and the average particle size of the migrating particles 32A, 32B, 32C, and 32D is, for example, 1.2 ⁇ m (electrophoretic particle 32A), 1 ⁇ m (electrophoretic particle 32B), 0.8 ⁇ m (electrophoretic particle 32C), and 0.6 ⁇ m (electrophoretic particle 32D).
  • the average particle size of each migrating particle 32A, 32B, 32C, 32D is not limited to the above value.
  • the smaller migrating particle has an average particle size a 1 and a particle size dispersion value ⁇ 1 and a larger side. If the electrophoretic particles and the average particle diameter a 2 and a particle size distribution value sigma 2, may be a relationship between a 1 -2 ⁇ 1> a 2 + 2 ⁇ 2.
  • the migrating particles 32 (32A, 32B, 32C, 32D) can move between the pixel electrode 14 and the counter electrode 22 in the insulating liquid 31.
  • the migrating particles 32 are, for example, one kind or two or more kinds of particles (powder) such as an organic pigment, an inorganic pigment, a dye, a carbon material, a metal material, a metal oxide, glass, or a polymer material (resin). .
  • the migrating particles 32 may be pulverized particles or capsule particles of resin solids containing the above-described particles. However, materials corresponding to carbon materials, metal materials, metal oxides, glass, or polymer materials are excluded from materials corresponding to organic pigments, inorganic pigments, or dyes.
  • Organic pigments include, for example, azo pigments, metal complex azo pigments, polycondensed azo pigments, flavanthrone pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, perylene pigments, perinones. Pigments, anthrapyridine pigments, pyranthrone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments or indanthrene pigments.
  • Inorganic pigments include, for example, zinc white, antimony white, carbon black, iron black, titanium boride, bengara, mapico yellow, red lead, cadmium yellow, zinc sulfide, lithopone, barium sulfide, cadmium selenide, calcium carbonate, barium sulfate, Lead chromate, lead sulfate, barium carbonate, lead white or alumina white.
  • the dye include nigrosine dyes, azo dyes, phthalocyanine dyes, quinophthalone dyes, anthraquinone dyes, and methine dyes.
  • the carbon material is, for example, carbon black.
  • the metal material is, for example, gold, silver or copper.
  • metal oxides include titanium oxide, zinc oxide, zirconium oxide, barium titanate, potassium titanate, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, and copper-chromium-manganese oxide. Or copper-iron-chromium oxide.
  • the polymer material is, for example, a polymer compound in which a functional group having a light absorption region in the visible light region is introduced. As long as the polymer compound has a light absorption region in the visible light region, the type of the compound is not particularly limited.
  • Specific materials for forming the migrating particles 32 are selected according to, for example, the role that the migrating particles 32 play in order to cause contrast.
  • the material in which white display is performed by the migrating particles 32 is, for example, a metal oxide such as titanium oxide, zinc oxide, zirconium oxide, barium titanate or potassium titanate, and among these, titanium oxide is preferable. This is because it is excellent in electrochemical stability and dispersibility and has high reflectance.
  • the material in the case where black display is performed by the migrating particles 32 is, for example, a carbon material or a metal oxide.
  • the carbon material is, for example, carbon black
  • the metal oxide is, for example, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, copper-chromium-manganese oxide, or copper-iron. -Chromium oxide and the like.
  • a carbon material is preferable. This is because excellent chemical stability, mobility and light absorption are obtained.
  • the migrating particles 32A, 32B, 32C, and 32D exhibit cyan, magenta, yellow, and black, respectively.
  • the electrophoretic particles 32D exhibiting black are formed of the carbon material or the metal oxide.
  • the migrating particles 32A exhibiting a cyan color, the migrating particles 32B exhibiting a magenta color, and the migrating particles 32C exhibiting a yellow color can be formed using pigments exhibiting corresponding colors.
  • Specific materials include, for example, quinacridone, perylene, perinone, isoindolinone, dioxazine, isoindoline, anthraquinone, quinophthalone, diketopyrrolopyrrole, and other polycyclic pigments, phthalocyanine pigments, azo lake red, azo lake red, piazolone, Examples thereof include azo pigments such as disazo, monoazo, condensed azo, naphthol, and pendimidazolone, and inorganic pigments such as cadmium yellow, strontium chromate, viridian, oxide chromium, cobalt blue, and ultramarine.
  • the content (concentration) of the migrating particles 32 (32A, 32B, 32C, and 32D) in the insulating liquid 31 is not particularly limited, but the entire migrating particles 32 are, for example, 0.1 wt% to 10 wt%. It is preferable. This is because the shielding property of the porous layer 33 by the migrating particles 32 and the concealing property and mobility of the migrating particles 32 by the porous layer 33 are ensured. If the amount is less than 0.1% by weight, the migrating particles 32 may hardly shield the porous layer 33. On the other hand, when the amount is more than 10% by weight, the dispersibility of the migrating particles 32 is lowered, so that the migrating particles 32 are difficult to migrate and may be aggregated in some cases.
  • the electrophoretic particles 32A, 32B, 32C, and 32D colored in the respective colors may be, for example, 0.1% by weight to 4% by weight for the electrophoretic particle 32A having the largest particle size, and the next largest electrophoretic particle For particles 32B, 0.1% to 4% by weight, for the next larger migrating particles 32C, 0.1% to 4% by weight, and for the smallest migrating particles 32D, 0.1% to 4% by weight.
  • the migrating particles 32 are easily dispersed and charged in the insulating liquid 31 for a long period of time and are not easily adsorbed by the porous layer 33.
  • a dispersant or a charge adjusting agent
  • the electrophoretic particles 32 may be subjected to a surface treatment, or both may be used in combination.
  • the dispersing agent is, for example, Solsperse series manufactured by Lubrizol, BYK® series or Anti-Terra® series manufactured by BYK-Chemie, or Span series manufactured by ICI® Americas®.
  • the surface treatment is, for example, rosin treatment, surfactant treatment, pigment derivative treatment, coupling agent treatment, graft polymerization treatment or microencapsulation treatment.
  • graft polymerization treatment, microencapsulation treatment, or a combination thereof is preferable. This is because long-term dispersion stability and the like can be obtained.
  • the surface treatment material is, for example, a material (adsorbing material) having a functional group and a polymerizable functional group that can be adsorbed on the surface of the migrating particle 32.
  • the type of functional group that can be adsorbed is determined according to the material for forming the migrating particles 32.
  • carbon materials such as carbon black are aniline derivatives such as 4-vinylaniline, and metal oxides are organosilane derivatives such as 3- (trimethoxysilyl) propyl methacrylate.
  • the polymerizable functional group include a vinyl group, an acrylic group, and a methacryl group.
  • the material for surface treatment is, for example, a material (graftable material) that can be grafted on the surface of the migrating particles 32 into which a polymerizable functional group is introduced.
  • the graft material preferably has a polymerizable functional group and a dispersing functional group that can be dispersed in the insulating liquid 31 and can maintain dispersibility due to steric hindrance.
  • the kind of polymerizable functional group is the same as that described for the adsorptive material.
  • the dispersing functional group is, for example, a branched alkyl group when the insulating liquid 31 is paraffin.
  • a polymerization initiator such as azobisisobutyronitrile (AIBN) may be used.
  • the porous layer 33 is, for example, a three-dimensional structure (irregular network structure such as a nonwoven fabric) formed by a fibrous structure 331 as shown in FIG.
  • the porous layer 33 has a plurality of gaps (pores 333) through which the migrating particles 32 pass in places where the fibrous structure 331 does not exist.
  • FIG. 1 the illustration of the porous layer 33 is simplified.
  • the fibrous structure 331 is a fibrous substance having a sufficiently large length with respect to the fiber diameter (diameter).
  • the shape (external appearance) of the fibrous structure 331 is not particularly limited as long as the fibrous structure 331 has a fibrous shape that is sufficiently long with respect to the fiber diameter as described above. Specifically, it may be linear, may be curled, or may be bent in the middle. Moreover, you may branch to 1 or 2 or more directions on the way, not only extending in one direction.
  • the formation method of the fibrous structure 331 is not particularly limited.
  • phase separation method for example, a phase separation method, a phase inversion method, an electrostatic (electric field) spinning method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, A sol-gel method or a spray coating method is preferred.
  • a fibrous material having a sufficiently large length with respect to the fiber diameter can be easily and stably formed.
  • the average fiber diameter of the fibrous structure 331 is not particularly limited, but is preferably as small as possible. This is because light easily diffuses and the average pore diameter of the pores 333 increases. However, the average fiber diameter is preferably determined so that the fibrous structure 331 can hold the non-migrating particles 332. For this reason, it is preferable that the average fiber diameter of the fibrous structure 331 is 10 micrometers or less. In addition, although the minimum of an average fiber diameter is not specifically limited, For example, it is 0.1 micrometer and may be less than that. This average fiber diameter is measured, for example, by microscopic observation using a scanning electron microscope (SEM) or the like. Note that the average length of the fibrous structure 331 may be arbitrary.
  • SEM scanning electron microscope
  • the fibrous structure 331 includes one or more non-migrating particles 332, and the non-migrating particles 332 are held by the fibrous structure 331.
  • the porous layer 33 which is a three-dimensional structure, one fibrous structure 331 may be entangled at random, or a plurality of fibrous structures 331 may be gathered and overlap at random. However, both may be mixed.
  • each fibrous structure 331 preferably holds one or more non-migrating particles 332.
  • FIG. 2 shows a case where the porous layer 33 is formed by a plurality of fibrous structures 331.
  • the porous layer 33 is a three-dimensional structure
  • the irregular three-dimensional structure easily causes external light to be irregularly reflected (multiple scattering), so that the light reflectance of the porous layer 33 increases and the high light
  • the porous layer 33 can be thin in order to obtain the reflectance.
  • the contrast increases and the energy required to move the migrating particles 32 decreases.
  • the migrating particles 32 can easily pass through the pores 333. As a result, the time required to move the migrating particles 32 is shortened, and the energy required to move the migrating particles 32 is also reduced.
  • non-migrating particles 332 are included in the fibrous structure 331 .
  • the non-migrating particles 332 are likely to cause irregular reflection of external light, and the light reflectance of the porous layer 33 becomes higher. Thereby, contrast becomes higher.
  • the porous layer 33 is constituted by a plurality of layers having different average pore diameters of the pores 333 as described above.
  • the porous layer 33 has a multilayer structure in which the same number of types of the average particle diameters of the migrating particles 32, that is, the same number of colors as the migrating particles 32 are laminated. Then, it has a configuration in which four types of layers (porous layers 33A, 33B, 33C, 33D) having different average pore diameters are laminated. These four types of porous layers 33A, 33B, 33C, and 33D are laminated so that the average pore diameter decreases from the display surface S1 side to the back surface S2 side.
  • the pore diameter of the porous layer 33 is not particularly limited, but is generally preferably as large as possible. This is because the migrating particles 32 easily pass through the pores 333.
  • the pore diameters of the porous layers 33A, 33B, 33C, and 33D are determined by the particle diameters of the migrating particles 32A, 32B, 32C, and 32D described above.
  • the porous layer 33A preferably has a pore diameter through which all the migrating particles 32A, 32B, 32C, and 32D can pass, and the average pore diameter is, for example, It is preferably in the range of 100 nm to 5 ⁇ m.
  • the porous layer 33B preferably has a pore diameter through which the migrating particles 32B, 32C, and 32D other than the migrating particle 32A can pass, and the average pore diameter is preferably in the range of, for example, 1.11 ⁇ m to 1.3 ⁇ m.
  • the porous layer 33C preferably has a pore diameter through which the migrating particles 32C and 32D other than the migrating particles 32A and 32B can pass, and the average pore diameter is preferably in the range of 0.91 ⁇ m to 1.1 ⁇ m, for example. .
  • the porous layer 33D has only to have a pore size through which only the migrating particles 32D can pass, and the pore size is preferably in the range of 0.71 ⁇ m to 0.9 ⁇ m, for example. Thereby, the moving distance between the driving substrate 10 and the counter substrate 20 of the migrating particles 32A, 32B, 32C, and 32D is controlled.
  • the thickness of the porous layers 33A, 33B, 33C, and 33D is not particularly limited.
  • the entire porous layer 33 is preferably 5 ⁇ m to 100 ⁇ m. This is because the concealability of the porous layer 33 is enhanced, and the migrating particles 32 can easily pass through the pores 333.
  • at least the thickness of the porous layer 33A disposed on the display surface side is at least a thickness capable of concealing the electrophoretic particles 32A when the electrophoretic particles 32A having the largest pore diameter move to the back surface S2. Is preferred.
  • the porous layers 33A, 33B, 33C, and 33D may have the same thickness as long as they are within the above range, but considering the time required for display switching, the migrating particles 32A, 32B, and 32C The moving distance of 32D is preferably shorter.
  • the thicknesses of the porous layers 33A, 33B, 33C, and 33D are preferably set in the following ranges, respectively.
  • the thickness of the porous layer 33A is preferably, for example, 10 ⁇ m or more and 30 ⁇ m or less
  • the thickness of the porous layer 33B is, for example, preferably 2 ⁇ m or more and 15 ⁇ m or less
  • the thickness of the porous layer 33C is, for example,
  • the thickness is preferably 2 ⁇ m or more and 15 ⁇ m or less
  • the thickness of the porous layer 33D is preferably, for example, 2 ⁇ m or more and 15 ⁇ m or less.
  • the fibrous structure 331 is formed including any one type or two or more types of polymer materials such as acrylic resins or inorganic materials, for example, and may include other materials.
  • the polymer material include nylon, polylactic acid, polyamide, polyimide, polyethylene terephthalate, polyacrylonitrile, polyethylene oxide, polyvinyl carbazole, polyvinyl chloride, polyurethane, polystyrene, polyvinyl alcohol, polysulfone, polyvinyl pyrrolidone, polyvinylidene fluoride, poly Examples thereof include hexafluoropropylene, cellulose acetate, collagen, gelatin, chitosan, and copolymers thereof.
  • the inorganic material include titanium oxide.
  • a polymer material is preferable as a material for forming the fibrous structure 331. This is because the reactivity (photoreactivity, etc.) is low, that is, because it is chemically stable, the unintended decomposition reaction of the fibrous structure 331 is suppressed. Note that in the case where the fibrous structure 331 is formed of a highly reactive material, the surface of the fibrous structure 331 is preferably covered with an arbitrary protective layer.
  • the fibrous structure 331 is preferably a nanofiber. Since the three-dimensional structure is complicated and it becomes easy to diffusely reflect external light, the light reflectance of the porous layer 33 is further increased, and the volume ratio of the pores 333 in the unit volume of the porous layer 33 is increased. This is because the migrating particles 32 can easily pass through the pores 333. Thereby, the contrast becomes higher and the energy required to move the migrating particles 32 becomes lower.
  • Nanofiber is a fibrous substance having a fiber diameter of 0.001 ⁇ m to 0.1 ⁇ m and a length that is 100 times or more of the fiber diameter.
  • the fibrous structure 331 that is a nanofiber is preferably formed by an electrospinning method using a polymer material. This is because the fibrous structure 331 having a small fiber diameter can be easily and stably formed.
  • the fibrous structure 331 has an optical reflection characteristic different from that of the migrating particles 32A, 32B, 32C, and 32D.
  • the light reflectance of the fibrous structure 331 is not particularly limited, but is preferably set so that at least the porous layer 33 can shield the migrating particles 32 as a whole. This is because the contrast is generated by utilizing the difference between the light reflectance of the migrating particles 32 and the light reflectance of the porous layer 33 as described above. Accordingly, the fibrous structure 331 having light transparency (colorless and transparent) in the insulating liquid 31 is not preferable.
  • the light reflectivity of the fibrous structure 331 hardly affects the light reflectivity of the entire porous layer 33, and the light reflectivity of the entire porous layer 33 is substantially the light reflectivity of the non-migrating particles 332.
  • the light reflectance of the fibrous structure 331 may be arbitrary.
  • Non-electrophoretic particles 332 are particles that are fixed to the fibrous structure 331 and do not migrate electrically.
  • the material for forming the non-electrophoretic particles 332 is, for example, the same as the material for forming the electrophoretic particles 32, and is selected according to the role played by the non-electrophoretic particles 332 as described later.
  • the non-migrating particle 332 may be partially exposed from the fibrous structure 331 or embedded therein.
  • the non-migrating particles 332 have optical reflection characteristics different from those of the migrating particles 32A, 32B, 32C, and 32D.
  • the light reflectance of the non-migrating particles 332 is not particularly limited, but is preferably set so that at least the porous layer 33 can shield the migrating particles 32 as a whole. This is because the contrast is displayed using the difference between the light reflectance of the migrating particles 32 and the light reflectance of the porous layer 33 as described above.
  • the specific forming material of the non-migrating particles 332 is selected according to the role played by the non-migrating particles 332 in order to generate contrast, for example.
  • the non-migrating particles 332 are preferably responsible for white display, for example. .
  • a metal oxide is preferable and titanium oxide is more preferable. This is because it is excellent in electrochemical stability and fixability, and high reflectance can be obtained.
  • the material for forming the non-migrating particles 332 may be the same material as the material for forming the migrating particles 32 or may be a different material.
  • the spacer 35 includes, for example, an insulating material such as a polymer material.
  • an insulating material such as a polymer material.
  • the configuration of the spacer 35 is not particularly limited, and may be a sealing material mixed with fine particles.
  • the shape of the spacer 35 is not particularly limited, but is preferably a shape that does not hinder the movement of the migrating particles 32 between the pixel electrode 14 and the counter electrode 22 and that can be uniformly distributed. is there. Further, the thickness of the spacer 35 (for example, the stacking direction of the porous layers 33A, 33B, 33C, and 33D) is not particularly limited, but in particular, it is preferably as thin as possible in order to reduce power consumption. 100 ⁇ m. In addition, in FIG. 1, the structure of the spacer 35 is simplified and shown.
  • the display device 1 includes a pair of substrates, the drive substrate 10 and the counter substrate 20 that are opposed to each other with the spacer 35 interposed therebetween, and includes a display layer therebetween.
  • the driving substrate 10 is, for example, one in which a thin film transistor (TFT) 12, a protective layer 13, and a pixel electrode 14 are laminated in this order on one surface of a support member 11.
  • TFT thin film transistor
  • the TFT 12 and the pixel electrode 14 are divided and formed in a matrix according to the pixel arrangement, for example, in order to construct an active matrix drive circuit.
  • the support member 11 is formed of, for example, one or more of inorganic materials, metal materials, plastic materials, and the like.
  • inorganic material include silicon (Si), silicon oxide (SiO x ), silicon nitride (SiN x ), and aluminum oxide (AlO x ).
  • Silicon oxide includes, for example, glass or spin-on-glass (SOG).
  • metal material include aluminum (Al), nickel (Ni), and stainless steel.
  • plastic material examples include polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethyl ether ketone (PEEK), cycloolefin polymer (COP), polyimide (PI), and polyether sulfone (PES). ) And the like.
  • the support member 11 may be light transmissive or non-light transmissive.
  • the support member 11 may be a rigid substrate such as a wafer, or may be a flexible thin glass or film. However, since a flexible (foldable) electronic paper display can be realized, it is desirable to be made of a flexible material.
  • the TFT 12 is a switching element for selecting a pixel.
  • the TFT 12 may be, for example, an inorganic TFT using an inorganic semiconductor layer such as amorphous silicon, polysilicon, or oxide as a channel layer (active layer), or an organic TFT using an organic semiconductor layer such as pentacene.
  • the TFT 12 is covered with, for example, a protective layer 13.
  • a flattening insulating film (not shown) made of an insulating material such as polyimide may be further provided on the protective layer 13.
  • the pixel electrode 14 is formed independently for each pixel, and includes, for example, one or more of conductive materials such as gold (Au), silver (Ag), and copper (Cu). Has been.
  • the pixel electrode 14 is electrically connected to the TFT 12. Note that the number of TFTs 12 arranged for one pixel electrode 14 is arbitrary, and is not limited to one, and may be two or more.
  • the adhesive layer 15 is bonded to the drive substrate 10 and a display layer described later, and is made of, for example, an acrylic resin, a urethane resin, or rubber, and has a thickness of, for example, 1 ⁇ m to 100 ⁇ m.
  • an anionic additive, a cationic additive, or a lithium salt additive may be added to the adhesive layer 15 for the purpose of providing conductivity.
  • the counter substrate 20 is provided with a counter electrode 22 on one surface side (display layer side) of the support member 21.
  • a color filter, an adhesive layer, and the like may be laminated.
  • the support member 21 is made of the same material as the support member 11 except that it is light transmissive. This is because the image is displayed on the upper surface side of the counter substrate 20, and thus the support member 21 needs to be light transmissive.
  • the thickness of the support member 21 is, for example, 1 ⁇ m to 250 ⁇ m.
  • the counter electrode 22 is formed including, for example, any one type or two or more types of conductive materials (transparent conductive materials) having optical transparency. Examples of such a conductive material include indium oxide-tin oxide (ITO), antimony oxide-tin oxide (ATO), fluorine-doped tin oxide (FTO), and aluminum-doped zinc oxide (AZO).
  • ITO indium oxide-tin oxide
  • ATO antimony oxide-tin oxide
  • FTO fluorine-doped tin oxide
  • AZO aluminum-doped zinc oxide
  • the thickness of the counter electrode 22 is, for example, 0.001 ⁇ m to 1 ⁇ m.
  • the counter electrode 22 is formed on the entire surface of the support member 21, for example. However, like the pixel electrode 14, the counter electrode 22 may be formed separately for each pixel, for example.
  • the light transmittance of the counter electrode 22 is preferably as high as possible, for example, 80% or more. is there.
  • the electric resistance of the counter electrode 22 is preferably as low as possible, for example, 100 ⁇ / ⁇ (square) or less.
  • an electrophoretic element 30 that is voltage-controlled for each pixel.
  • the electrophoretic element 30 generates contrast using an electrophoretic phenomenon, and includes electrophoretic particles 32 that can move between the pixel electrode 14 and the counter electrode 22 in accordance with an electric field.
  • the electrophoretic element 30 includes the porous layer 33 together with the electrophoretic particles 32 in the insulating liquid 31.
  • the insulating liquid 31 and the porous layer 33 are common to each pixel. Is provided.
  • the display device 1 is manufactured as follows, for example. First, the counter electrode 22 is provided on one surface of the support member 21 using an existing method such as various film forming methods, and the counter substrate 20 is formed. Next, a spacer 35 is formed on the counter electrode 22.
  • the spacer 35 can be formed by, for example, the following imprint method. First, a solution containing a constituent material (for example, a photosensitive resin material) of the spacer 35 is applied onto the counter electrode 22. Next, a mold having a recess on the coated surface is pressed and exposed to light, and then the mold is removed. Thereby, the columnar spacer 35 is formed.
  • the porous layer 33 is disposed between the adjacent spacers 35, that is, in the cells 34.
  • the porous layer 33 is formed through the following steps. First, a spinning solution is prepared by dispersing or dissolving a material for forming the fibrous structure 331 (for example, a polymer material) in an organic solvent or the like. Subsequently, after adding the non-migrating particles 332 to the spinning solution, the non-migrating particles 332 are dispersed in the spinning solution by sufficiently stirring. Next, using this spinning solution, for example, spinning is performed by an electrostatic spinning method. Thereby, the porous layer 33 in which the non-migrating particles 332 are held by the fibrous structure 331 is formed.
  • a spinning solution is prepared by dispersing or dissolving a material for forming the fibrous structure 331 (for example, a polymer material) in an organic solvent or the like.
  • the non-migrating particles 332 are dispersed in the spinning solution by sufficiently stirring.
  • spinning solution for example,
  • the pore diameter of the porous layer 33 is controlled by controlling the viscosity of the spinning solution, the particle diameter of the non-electrophoretic particles 332, and the scanning speed during electrostatic spinning.
  • the thickness compression amount of the porous layer 33A is 0% to 10%
  • the porous layer 33B is 10% to 20%
  • the porous layer 33C is 20% to 30%
  • the porous layer 33D is 30% to 40%.
  • the porous layer 33A, 33B, 33C, 33D having the above average pore diameter range is formed by compressing the porous membrane using the% condition.
  • the fibrous structure 331 is formed by a phase separation method, a phase inversion method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, a sol-gel method, a spray coating method, or the like instead of the electrostatic spinning method. May be.
  • the insulating liquid 31 in which the migrating particles 32A, 32B, 32C, and 32D are dispersed to the counter substrate 20 on which the porous layer 33 is disposed this is treated with, for example, a sealing agent (not shown).
  • a peeling member (not shown) provided with the seal layer 16 is opposed.
  • the driving substrate 10 on which the TFT 12 and the pixel electrode 14 and the like are formed on the seal layer 16 via the adhesive layer 15 is fixed.
  • the display device 1 is completed through the above steps.
  • contrast is generated by utilizing the difference between the light reflectance of the electrophoretic particles 32 and the light reflectance of the porous layer 33.
  • FIG. 3A and 3B are schematic diagrams for explaining a basic display operation of the electrophoretic element 30.
  • FIG. Here, for the sake of clarity, the porous layer 33 is shown as a single layer, and the region in which the migrating particles 32 are disposed between the porous layer 33 and the drive substrate 10 and the counter substrate 20 (standby region R1). And the display region R2). Further, the migrating particle 32D having the smallest particle size will be described as an example.
  • the migrating particles 32D are arranged in the standby region R1 (FIG. 3A). In this case, since the migrating particles 32D are concealed by the porous layer 33 in all the pixels, no contrast is generated when the electrophoretic element 30 is viewed from the counter substrate 20 side (an image is not displayed). Is in a state.
  • the migrating particles 32D are transferred from the standby region R1 to the porous layer 33 for each pixel. It moves to the display region R2 via the pore 333.
  • the migrating particles 32 are both concealed by the porous layer 33 and non-hidden, the contrast is generated when the electrophoretic element 30 is viewed from the counter substrate 20 side. become. Thereby, an image is displayed.
  • the drive substrate 10 is provided with a peripheral circuit (not shown) for driving the electrophoretic element 30 for each pixel (applying a drive voltage between the pixel electrode 14 and the counter electrode 22).
  • the peripheral circuit includes, for example, a voltage control driver for forming an active matrix driving circuit, a power source, a memory, and the like, and corresponds to an image signal for one or more selective sub-pixels. A drive voltage can be applied.
  • the electrophoretic element 30 has a plurality of types of average particle diameters in the insulating liquid 31, and the electrophoretic particles 32A, 32B, 32C, which are color-coded according to the average particle diameter.
  • 32D and porous layers 33A, 33B, 33C, and 33D having pores 333 having different average pore diameters.
  • FIG. 4 is a schematic diagram for explaining the operation of the display device 1.
  • the porous layer 33 has a larger average pore diameter from the display surface S1 side, here, the porous layer 33A, the porous layer 33B, and the porous layer 33C from the display surface S1 side. And the porous layer 33D in this order.
  • the average pore diameter of the porous layers 33A, 33B, 33C, and 33D is determined by the migrating particles 32A, 32B, 32C, and 32D.
  • the pore size of the porous layer 33A is such that all the migrating particles 32A, 32B, 32C, and 32D can pass, and the pore size of the porous layer 33B cannot pass the migrating particle 32A, but the migrating particles 32B, 32C,
  • the porous layer 33C cannot pass through the migrating particles 32A and 32B, but the porous layer 33C can pass through the migrating particles 32A, 32B, and 32C.
  • the migrating particles 32A, 32B, 32C, and 32D can be kept at different positions.
  • FIGS. 5A to 7B are conceptual diagrams (FIGS. 5A, 6A, and 7A) showing movement of the migrating particles 32A, 32B, 32C, and 32D for explaining the display operation of the display device 1, and waveforms of applied voltages (FIG. 5B). 6B and FIG. 7B).
  • the electrophoretic particles 32A, 32B, 32C, and 32D are colored cyan (electrophoretic particles 32A), magenta (electrophoretic particles 32B), yellow (electrophoretic particles 32C), and black (electrophoretic particles 32D), respectively. .
  • the movement of the migrating particles 32A, 32B, 32C, and 32D and the waveform of the applied voltage when performing cyan display, magenta display, and yellow display will be described in this order.
  • the electrophoretic element 30 of the present embodiment in the initial state (a state in which no voltage is applied between the pixel electrode 14 and the counter electrode 22), the electrophoretic particles 32A, 32B, 32C, and 32D are on standby. It is localized in the region R1. Specifically, the migrating particles 32A, 32B, 32C, and 32D are respectively disposed on the back surface S2 side of the porous layers 33A, 33B, 33C, and 33D that can pass (time 0 in FIG. 5A). At this time, the display color is the color of the porous layer 33, that is, white.
  • the migrating particles 32A, 32B, 32C, and 32D move to the display surface S1 side.
  • FIG. 5B when a positive voltage is applied for a certain time (specifically, until the migrating particles 32A reach the display surface S1) and then stopped, as shown in FIG.
  • the particles 32A are arranged on the outermost surface of the porous layer 33, and the migrating particles 32B, 32C, and 32D are arranged in the porous layer 33. That is, the display color of the pixel including the electrophoretic element 30 is cyan.
  • the magenta display will be described.
  • the migrating particles 32B colored in magenta are arranged on the display surface S1 side.
  • 32C and 32D are arranged in the porous layer 33.
  • the electrophoretic particles 32A are positioned on the back surface S2 side in the initial state.
  • the migrating particles 32B move to the display surface S1.
  • the migrating particles 32A having a larger moving speed than the migrating particles 32B move to the back surface S2 side before the migrating particles 32B.
  • the migrating particles 32B are arranged on the outermost surface of the porous layer 33, and the migrating particles 32A and the other migrating particles 32C and 32D are arranged in the porous layer 33. That is, the display color of the pixel provided with the electrophoretic element 30 is magenta.
  • electrophoretic particles 32C colored yellow are disposed on the display surface S1 side.
  • the migrating particles 32 ⁇ / b> A, 32 ⁇ / b> B, and 32 ⁇ / b> D are arranged in the porous layer 33. More specifically, as shown in FIG. 7A, by applying a positive voltage for a longer time than when displaying magenta, as shown in FIG. 7B, in the initial state, the back side S2 side of the migrating particles 32A and 32B.
  • the positioned migrating particles 32C move to the display surface S1. Thereafter, when a negative voltage is applied, the migrating particles 32A, 32B, 32C, and 32D start to move toward the back surface S2. At this time, since the migrating particles 32A and 32B have a higher moving speed than the migrating particles 32C, they move to the back surface S2 side before the migrating particles 32C.
  • the migrating particles 32C are arranged on the outermost surface of the porous layer 33, and the migrating particles 32A, 32B, and 32D are arranged in the porous layer 33. That is, the display color of the pixel including the electrophoretic element 30 is yellow.
  • the display color of the pixel including the electrophoretic element 30 is black, for example, a positive voltage is applied for a longer time than yellow display, and then a negative voltage is applied from yellow display.
  • the migrating particles 32D colored black on the outermost surface of the porous layer 33 are in a state in which the migrating particles 32A, 32B, and 32C are arranged in the porous layer 33.
  • the display color of the pixel including the electrophoretic element 30 is black.
  • the electrophoretic element 30 controls the direction (positive / negative) and application time of the applied voltage, so that it is multicolored, in this case, cyan, magenta, yellow, black, and White five-color display is possible.
  • FIG. 8A and FIG. 8B are a conceptual diagram (FIG. 8A) showing the movement of electrophoretic particles in an electrophoretic element as a comparative example, and a waveform diagram of an applied voltage (FIG. 8B).
  • This electrophoretic element controls the display color only by the difference in the moving speed of the electrophoretic particles of each color, like the electrophoretic element provided in the display device described in Patent Document 1.
  • the electrophoretic element has four types of electrophoretic particles 132A, 132B, 132C, and 132D as in the present embodiment.
  • the size and the color of each migrating particle 132A, 132B, 132C, 132D are the same as those of the migrating particle 32A, 32B, 32C, 32D of the present embodiment, respectively.
  • the electrophoretic particles 132C are all localized on the back surface S200 in the initial state. For this reason, in order to move the yellow electrophoretic particles 132C to the display surface S100, it takes a longer time than the electrophoretic element 30 of the present embodiment (see FIGS. 8A and 8B).
  • the time is longer than that of the electrophoretic element 30. Cost.
  • examples of a reflective display device capable of multicolor display include a display device provided with a color filter.
  • the color filter when the color filter is provided, there is a risk that the contrast and the brightness may be significantly reduced due to a decrease in reflectance due to the provision of the color filter and absorption of reflected light by the color filter.
  • the migrating particles 32 four types of migrating particles 32A, 32B, 32C, which have different average particle sizes and are colored in different colors for each average particle size. 32D was used.
  • the porous layer 33 is composed of four types of porous layers 33A, 33B, 33C, and 33D having different average pore diameters of the pores 333, and these average pore diameters decrease from the display surface S1 side to the back surface S2 side. Laminated in order. Thereby, the moving distance of each color migrating particle 32A, 32B, 32C, 32D is limited by the particle diameter and the pore diameter of the porous layers 33A, 33B, 33C, 33D.
  • the migrating particles 32A, 32B, 32C, and 32D are localized on the back surface S2 side of the porous layers 33A, 33B, 33C, and 33D that can pass, respectively, in the initial state, for example.
  • the moving distance of the particles 32A, 32B, 32C, 32D is shorter in the migrating particles 32A, 32B, 32C other than the migrating particle 32D having the smallest particle size.
  • the plurality of types of migrating particles 32 having different average particle diameters and different colors for each average particle diameter, and the display surface S1 side to the back surface S2 side.
  • the electrophoretic element 30 including a plurality of types of porous layers 33 stacked in order of decreasing average pore diameter is used as a display element.
  • the position of the migrating particle 32 (32A, 32B, 32C, 32D) in the initial state is controlled by the pore diameter of the laminated porous layer 33 (33A, 33B, 33C, 33D).
  • the migrating particle 32A having the largest particle size is arranged at the position closest to the display surface S1
  • the migrating particle 32D having the smallest particle size is arranged at the position farthest from the display surface S1. Therefore, when performing a certain color display, the electrophoretic particles exhibiting a desired color are arranged on the display surface S1 by applying a voltage, and the electrophoretic particles of other colors are moved and concealed in the porous layer. It is possible to shorten the sorting time. That is, it is possible to shorten the time required for display switching. Therefore, it is possible to provide the display device 1 capable of multicolor display while improving display quality.
  • FIG. 9 illustrates a cross-sectional configuration of a display device (display device 2) according to Modification 1 of the above embodiment.
  • the display device 2 is applied to various electronic devices such as an electronic paper display, for example, an electronic paper display that generates contrast by using an electrophoretic phenomenon and displays an image.
  • the display device 2 includes, for example, a display layer including the electrophoretic element 30 between the drive substrate 10 and the counter substrate 20 that are disposed to face each other with the spacer 35 interposed therebetween.
  • the electrophoretic element 40 includes an insulating liquid 41 including electrophoretic particles 42 and a porous layer 43 having a plurality of pores.
  • the porous layer 43 has a fibrous structure and non-migrating particles held by the fibrous structure (none of which are shown).
  • FIG. 9 schematically shows the configuration of the electrophoretic element 40 and may differ from the actual size and shape.
  • the electrophoretic element 40 of the present modification has a plurality of types of average particle diameters, for example, the electrophoretic particles 42A and the electrophoretic particles 42B having different average particle diameters as the electrophoretic particles 42.
  • the porous layer 43 includes a plurality of types of average pore diameters, for example, a porous layer 43A and a porous layer 43B having different average pore diameters.
  • the migrating particles 42A and 42B and the porous layers 43A and 43B are charged, and the charge amounts are different from those of the above embodiment.
  • positioned at the display surface S1 side and the porous layer 43A with a large hole diameter at the back surface S2 side is different from the said embodiment.
  • the insulating liquid 41 is, for example, any one type or two or more types of non-aqueous solvents such as organic solvents, and specifically includes paraffin or isoparaffin. Yes. It is preferable that the viscosity and refractive index of the insulating liquid 41 are as low as possible. This is because the mobility (response speed) of the migrating particles 32 is improved, and the energy (power consumption) required to move the migrating particles 32 is lowered accordingly. Moreover, since the difference between the refractive index of the insulating liquid 41 and the refractive index of the porous layer 33 is increased, the light reflectance of the porous layer 33 is increased. Note that a weak conductive liquid may be used instead of the insulating liquid 41.
  • the insulating liquid 41 may contain various materials (for example, a colorant, a charge control agent, a dispersion stabilizer, a viscosity modifier, a surfactant, or a resin) as necessary.
  • the electrophoretic particles 42 are one or more charged particles that are electrically movable, and are dispersed in the insulating liquid 41.
  • the migrating particles 42 in the present modification include the migrating particles 42A and 42B having different average particle diameters, and are each composed of one or two or more charged particles.
  • the migrating particles 42A and 42B are colored in different colors. Specifically, the electrophoretic particles 42A and 42B are colored, for example, red (electrophoretic particles 42A) and black (electrophoretic particles 42B).
  • the particle size of the migrating particles 42 is preferably in the range of, for example, 0.1 ⁇ m or more and 2 ⁇ m or less, and the migrating particles 42A and 42B have, for example, 0.2 ⁇ m (migrating particles 42A) and 0.3 ⁇ m in this range. (Electrophoretic particle 42B).
  • the average particle diameter of each migrating particle 42A and 42B is not limited to the said range, For example, an average particle diameter should just be 0.1 micrometer or more.
  • the migrating particles 42A and 42B may be any of organic pigments, inorganic pigments, dyes, carbon materials, metal materials, metal oxides, glass, polymer materials (resins), and the like, as with the migrating particles 32 in the above embodiment. Or one kind or two or more kinds of particles (powder).
  • the content (concentration) of the migrating particles 42A and 42B in the insulating liquid 41 is not particularly limited, but the entire migrating particle 42 is preferably, for example, 0.1 wt% to 10 wt%. This is because the shielding property of the porous layer 33 by the migrating particles 32 and the concealing property and mobility of the migrating particles 32 by the porous layer 33 are ensured. If the amount is less than 0.1% by weight, the migrating particles 32 may hardly shield the porous layer 33. On the other hand, when the amount is more than 10% by weight, the dispersibility of the migrating particles 32 is lowered, so that the migrating particles 32 are difficult to migrate and may be aggregated in some cases. For example, both the migrating particles 42A and the migrating particles 42B are preferably 0.1% by weight to 4% by weight although the migrating particles 42A and 42B depend on the particle size, surface modification, or material.
  • the migrating particles 42A and 42B in this modification are charged and have different charge amounts.
  • This difference in charge amount can be added, for example, by performing a surface treatment.
  • a charge difference can be provided by modifying an electron-withdrawing functional group having a different charge amount.
  • a charge difference can be provided by modifying functional groups having electron donating properties having different charge amounts.
  • the charge difference can also be provided by changing the amount of the functional group to be modified on the surfaces of the migrating particles 42A and 42B.
  • the charge amounts of the migrating particles 42A and the migrating particles 42B are determined from the relationship with the charge amounts of the porous layer 43A and the porous layer 43B described later. This is because the moving speed of the migrating particles 42A and 42B at the time of voltage application is differentiated to further improve the display switching speed. Specifically, the mobility of the migrating particles 42 increases in the case of a combination with a small charge difference between the migrating particles 42 and the porous layer 43, and the migration of the migrating particles 42 in a combination with a large charge difference. The degree is small. If the charge difference is too large, the migrating particles 42 cannot pass through the porous layer 43.
  • the charge amount of the migrating particles 42B is preferably larger than the charge amount of the migrating particles 42A having a small particle size, for example.
  • the charge amount of the migrating particles 42A is preferably 10 mV or more and 50 mV or less, for example, and the charge amount of the migrating particles 42B is preferably 20 mV or more and 100 mV or less, for example.
  • the porous layer 43 is a three-dimensional solid structure (irregular network structure such as a nonwoven fabric) formed of a fibrous structure as in the above embodiment.
  • the porous layer 43 in this modification has two types of porous layers 43A and porous layers 43B having different pore sizes.
  • the porous layers 43A and 43B are charged and have different charge amounts.
  • the order of stacking the porous layers 43A and 43B is such that a porous layer 43A having a small average pore diameter is arranged on the display surface S1 side, and a porous layer 43B having a large average pore diameter is arranged on the back surface S2 side. Yes.
  • the materials described in the above embodiment can be used.
  • the porous layer 43A disposed on the display surface S1 side may have light reflectivity, but in this modification, the pore size of the porous layer 43A cannot pass through the migrating particles 42B, so that light transmission is possible. It is preferable to have properties.
  • the fibrous structure constituting the porous layer 43A is formed without including non-electrophoretic particles that add optical reflection characteristics.
  • the porous layer 43B disposed on the back surface S2 side is composed of a fibrous structure including one or two or more non-electrophoretic particles, like the porous layer 33 in the above embodiment, and the electrophoretic particles 42A, It has a light reflection characteristic different from 42B.
  • the average pore diameter of the porous layers 43A and 43B is not particularly limited, but the average pore diameter of the porous layer 43B disposed on the back surface S2 side is preferably as large as possible. This is because the migrating particles 42A and 42B easily pass through the pores. For this reason, the average pore diameter of the pores of the porous layer 43B is preferably in the range of 0.5 ⁇ m or more and 1.5 ⁇ m or less, for example. On the other hand, it is desirable that the average pore size of the pores of the porous layer 43A is a pore size through which the large migrating particles 42B cannot pass. For this reason, it is preferable that the average pore diameter of the pores of the porous layer 43B is, for example, in the range of 0.1 ⁇ m to 5 ⁇ m.
  • the thickness of the porous layers 43A and 43B is not particularly limited.
  • the thickness of the entire porous layer 43 is preferably, for example, 5 ⁇ m to 100 ⁇ m. This is because the concealability of the porous layer 43 is enhanced and the migrating particles 42 easily pass through the pores.
  • the thickness of the porous layer 43A is not particularly limited.
  • the thickness of the mass layer 43B is preferably a thickness that can shield the migrating particles 42B having a large particle diameter, and is preferably in the range of 2 ⁇ m to 15 ⁇ m, for example.
  • the porous layers 43A and 43B are charged and have different charge amounts.
  • the porous layers 43A and 43B can be charged, for example, by containing an inorganic pigment.
  • the difference in charge amount can be provided, for example, by changing the surface treatment method.
  • the charge amount of the porous layer 43A and the porous layer 43B is determined from the relationship with the charge amount of the migrating particles 42A and the migrating particles 42B.
  • the charge amount of the porous layer 43A disposed on the display surface S1 side is preferably smaller than the charge amount of the porous layer 43B.
  • the charge amounts of the porous layer 43A and the porous layer 43B are, for example, 0 mV or more and 50 mV or less (porous layer 43A), respectively.
  • it is preferably 20 mV or more and 100 mV or less (porous layer 43B).
  • the electrophoretic element 40 of this modification includes the electrophoretic particles 42A and 42B having different average particle diameters and the porous layers 43A and 43B having different average pore diameters.
  • the electrophoretic particles 42A and 42B and the porous layers 43A and 43B are charged and have different charge amounts. Specifically, the charged amount of the electrophoretic particle 42B having a larger particle diameter than that of the electrophoretic particle 42A is increased, and the charged amount of the porous layer 43B having a larger pore diameter than that of the porous layer 43A is increased. Thereby, the difference in the moving speed of the migrating particles 42A and 42B at the time of voltage application is increased. Therefore, it is possible to further reduce the time required for display switching. Therefore, it is possible to provide the display device 2 capable of multicolor display with improved display quality.
  • the porous layers 43A and 43B having different pore diameters are arranged, the porous layer 43A having a small pore diameter is arranged on the display surface S1, and the porous layer 43B having a large pore diameter is arranged on the back surface S2.
  • the migrating particles 42A and 42B having different particle sizes cannot pass through the porous layer 43A.
  • the pore size is large on the display surface S1 side. You may make it arrange
  • the porous layer 43A preferably has the same light reflection characteristics as the porous layer 43B, and preferably contains non-electrophoretic particles.
  • the charge amount of the migrating particle 42B is 50 mV or more and 250 mV or less (same for the porous layer 43B) with respect to the charge amount of 10 mV or more and 50 mV or less for the migrating particle 42A (same for the porous layer 43A).
  • the particle diameters of the migrating particles 42A and 42B are different from each other, but may be the same.
  • the porous layers 43A and 43B may have the same pore diameter.
  • the charge amount and the difference between the migrating particles 42A and 42B and the charge amount and the difference between the porous layers 43A and 43B may be the same as the above range. For example, by setting the difference to 25 mV or more Thus, it is possible to realize a display device capable of multicolor display only by the difference in charge amount between the migrating particles 42A and 42B and the porous layers 43A and 43B.
  • 10A, 10B, and 10C schematically show the display operation of the electrophoretic particles 52A and 52B in the electrophoretic element 50 including the electrophoretic particles 52A and 52B having the same particle diameter and the porous layers 53A and 53B having the same pore diameter. It is a representation.
  • the migrating particles 52A and 52B and the porous layers 53A and 53B have different charge amounts. Specifically, for example, the migrating particles 52A are charged to 25 mV, the migrating particles 52B are charged to 100 mV, the porous layer 53A is charged to 0 mV, and the porous layer 53B is charged to 100 mV.
  • the migrating particles 52A are colored red, the migrating particles 52B are colored black, and the porous layer 53A disposed on the display surface S1 side is light transmissive.
  • the migrating particles 52A and 52B are both moved to the back surface S2
  • the migrating particles 52A and 52B are concealed by the porous layer 53B and displayed white.
  • the electrophoretic particles 52B In the initial state, when a voltage is applied for a certain period of time, in the electrophoretic element 50, the electrophoretic particles 52B having a larger charge amount move toward the display surface S1 before the electrophoretic particles 52A.
  • the potential difference between the migrating particles 52B and the porous layer 53A is large, the migrating particles 52B cannot pass through the porous layer 53A and remain at the boundary between the porous layer 53A and the porous layer 53B.
  • the migrating particle 52B remains at the boundary between the porous layer 53A and the porous layer 53B, and the migrating particle 52A has a lower moving speed than the migrating particle 52B. Returns to the back surface S2 side (pixel electrode side). As a result, the electrophoretic element 50 displays black. Further, when a voltage is applied for a longer time than when displaying black from the initial state, both the migrating particles 52A and the migrating particles 52B move to the boundary between the porous layer 53A and the porous layer 53B.
  • the migrating particles 52A pass through the porous layer 53A and reach the display surface S1. Thereafter, when the applied voltage is erased, as shown in FIG. 10C, the migrating particles 52A remain on the display surface S1, and the migrating particles 52B remain on the boundary between the porous layer 53A and the porous layer 53B.
  • the electrophoretic element 50 is displayed in red by the child.
  • FIG. 11 illustrates a cross-sectional configuration of a display device (display device 4) according to Modification 2 of the above embodiment.
  • the display device 4 is applied to various electronic devices such as an electronic paper display, for example, an electronic paper display that displays an image by generating contrast using an electrophoretic phenomenon.
  • the display device 4 includes, for example, a display layer including the electrophoretic element 60 between the drive substrate 10 and the counter substrate 20 that are disposed to face each other with the spacer 35 interposed therebetween.
  • the electrophoretic element 60 is configured to include an electrophoretic particle 62 and a porous layer 63 having a plurality of pores in an insulating liquid 61. Note that FIG. 11 schematically shows the configuration of the electrophoretic element 60 and may differ from the actual size and shape.
  • the electrophoretic element 60 of this modification has a plurality of types of electrophoretic particles having different average particle diameters (for example, electrophoretic particles 62A and electrophoretic particles 62B having different average particle diameters) as the electrophoretic particles 62.
  • the electrophoretic element 60 has a plurality of types of porous layers having different average pore diameters as the porous layer 63.
  • the porous layer 63 includes, for example, three porous layers 63A, 63B, and 63C, and the porous layer 63B has a larger average pore diameter than the porous layer 63A.
  • the porous layer 63A having a small average pore diameter is disposed on the display surface S1 side, and the porous layer 63B having a larger average pore diameter than the porous layer 63A is disposed on the back surface S2 side, and has light transmission properties.
  • the display device 4 of the present modification further has a configuration in which a porous layer 63C having optical reflection characteristics is disposed on the back surface S2 side of the porous layer 63B.
  • the insulating liquid 61 is, for example, any one type or two or more types of non-aqueous solvents such as organic solvents, and specifically includes paraffin or isoparaffin. Yes. It is preferable that the viscosity and refractive index of the insulating liquid 61 be as low as possible. This is because the mobility (response speed) of the migrating particles 62 is improved, and the energy (power consumption) required to move the migrating particles 62 is lowered accordingly. Moreover, since the difference between the refractive index of the insulating liquid 61 and the refractive index of the porous layer 63 becomes large, the light reflectance of the porous layer 63 becomes high.
  • the insulating liquid 61 may contain various materials (for example, a colorant, a charge control agent, a dispersion stabilizer, a viscosity modifier, a surfactant, or a resin) as necessary.
  • the electrophoretic particles 62 are one or more charged particles that are electrically movable and are dispersed in the insulating liquid 61.
  • the migrating particle 62 in the present modification includes the migrating particles 62A and 62B having different average particle diameters, and each is composed of one or more charged particles.
  • the migrating particles 62A and 62B are colored in different colors. Specifically, the migrating particles 62A are colored, for example, red (R), and the migrating particles 62B are colored, for example, black (B).
  • the particle size of the migrating particles 62 is preferably in the range of 0.1 ⁇ m to 2 ⁇ m, for example, and the migrating particles 62A and 62B are within this range, for example, 0.3 ⁇ m (migrating particles 62A) and 0.2 ⁇ m. (Electrophoretic particle 62B).
  • the average particle diameter of the migrating particles 62A and 62B is not limited to the above range, and for example, the average particle diameter may be 0.1 ⁇ m or more.
  • the migrating particles 62A and 62B are, for example, any of organic pigments, inorganic pigments, dyes, carbon materials, metal materials, metal oxides, glass, polymer materials (resins), and the like, similar to the migrating particles 62 in the above embodiment. Or one kind or two or more kinds of particles (powder).
  • the content (concentration) of the migrating particles 62A and 62B in the insulating liquid 61 is not particularly limited, but the entire migrating particle 62 is preferably, for example, 0.1 wt% to 10 wt%. This is because the shielding property of the porous layer 33 by the migrating particles 32 and the concealing property and mobility of the migrating particles 32 by the porous layer 33 are ensured. If the amount is less than 0.1% by weight, the migrating particles 62 may not easily shield the porous layer 63.
  • both the migrating particles 62A and the migrating particles 62B are preferably 0.1% by weight to 4% by weight although the migrating particles 62A and 62B depend on the particle size, surface modification, or material.
  • the migrating particles 62A and 62B in the present modification are charged with the same polarity and have different average moving speeds.
  • the average moving speed of the migrating particles 62A is smaller than the average moving speed of the migrating particles 62B.
  • the difference in the average moving speed is determined by, for example, the charge amount possessed by the migrating particles 62A and 62B.
  • the difference in charge amount can be added, for example, by performing a surface treatment as in the first modification.
  • a charge difference can be provided by modifying an electron-withdrawing functional group having a different charge amount. .
  • a charge difference can be provided by modifying functional groups having electron donating properties having different charge amounts.
  • the charging difference can also be provided by changing the amount of the functional group to be modified on the surfaces of the migrating particles 62A and 62B.
  • the porous layer 63 is, for example, a three-dimensional structure (irregularity such as a nonwoven fabric) formed by a fibrous structure (fibrous structure 331) as shown in FIG. Network structure).
  • the porous layer 63 in the present modification is composed of two kinds of porous layers 63A and 63B having different light diameters and having light transmission properties, and a porous layer 63C having optical reflection characteristics. Yes.
  • the order of lamination of the light-transmitting porous layer 63A and porous layer 63B is such that the porous layer 63A having a small average pore diameter on the display surface S1 side and the pore having a large average pore diameter on the back surface S2 side.
  • Layer 63B is disposed.
  • the porous layer 63C having optical reflection characteristics (light reflectance) is disposed on the back surface S2 side of the porous layer 63B.
  • the materials mentioned in the above embodiment can be used.
  • the light-transmitting porous layers 63A and 63B are composed of a fibrous structure that does not include non-electrophoretic particles (non-electrophoretic particles 332) as shown in FIG.
  • the porous layer 63C disposed on the back surface S2 side is composed of a fibrous structure including one or two or more non-electrophoretic particles, like the porous layer 63 in the above embodiment, and the electrophoretic particles 62A. , 62B have different light reflectivity.
  • the porous layers 63A and 63B preferably contain particles that do not reflect visible light (non-visible light particles).
  • Examples of the particles that do not reflect visible light include titania (TiO 2 ) having a particle size of 250 nm or less. This is because the holding performance of the migrating particles 62A and 62B in the porous layers 63A and 63B may be improved by forming the porous layers 63A and 63B using the fibrous structure containing TiO 2. is there.
  • the average pore sizes of the porous layers 63A and 63B are determined by the migrating particles 62A and 62B, respectively.
  • the average pore diameter of the pores of the porous layer 63A is preferably a pore diameter that allows the migrating particles 62B to pass through but does not allow the migrating particles 62A having a larger average particle diameter to pass through, for example, less than 0.3 ⁇ m. It is preferable that The average pore size of the porous layer 63B is not particularly limited as long as the migrating particles 62A and the migrating particles 62B can pass through, but is preferably as large as possible. This is because the migrating particles 62A and 62B easily pass through the pores.
  • the average pore diameter of the pores of the porous layer 63B is, for example, in the range of 0.3 ⁇ m to 5 ⁇ m. Further, the average pore size of the porous layer 63C only needs to allow the migrating particles 62A and the migrating particles 62B to pass through, and may be the same average pore size as the porous layer 63B or a larger average pore size.
  • the thickness of the entire porous layer 63 is not particularly limited, but is preferably 5 ⁇ m to 100 ⁇ m, for example.
  • the thicknesses of the porous layer 63A, the porous layer 63B, and the porous layer 63C with respect to the entire porous layer 63 are determined as follows, for example. First, the thickness (W1 (porous layer 63A) and W2 (porous layer 63B)) of the light-transmitting porous layers (porous layer 63A and porous layer 63B) is such that migrating particles 62B having a higher moving speed.
  • (W1 + W2) W ⁇ (V2 / V1), where V1 is the average migration speed of V2, V2 is the average migration speed of the migrating particles 62A, and W is the total thickness of the porous layer 63.
  • the thickness (W3) of the porous layer 63C having light reflection characteristics is a thickness obtained by subtracting the thickness (W1 + W2) of the porous layer 63A and the porous layer 63B from the thickness (W) of the entire porous layer 63.
  • the porous layer 63A and the porous layer 63B having light transmittance are provided on the display surface S1 side, and the porous layer 63A having a small average pore diameter is provided on the display surface S1 side.
  • the porous layer 63B having a larger average pore diameter than the porous layer 63A is arranged on the back surface S2 side.
  • a porous layer 63C having light reflectivity is disposed on the back surface S2 side of the porous layer 63B.
  • the electrophoretic particles 62A and the electrophoretic particles 62B having a smaller particle diameter than the electrophoretic particles 62A are used as the electrophoretic particles 62.
  • the average particle size of the migrating particles 62A and 62B and the average pore size of the porous layers 63A, 63B, and 63C are such that the migrating particles 62B can pass through the pores of the porous layer 63A, but the migrating particles 62A are fine particles of the porous layer 63A.
  • the size is such that it cannot pass through the hole.
  • the pores of the porous layer 63B and the porous layer 63C are sized so that both the migrating particles 62A and the migrating particles 62B can pass through.
  • the application time of the voltage applied between the pixel electrode 14 and the counter electrode 22 is controlled as in the above embodiment, so that the pixel electrode 14 and the counter electrode 22
  • the average distribution position of the migrating particles 62A (red; R) and 62B (black; B) can be controlled to switch between red display (R), black display (B), and white display (W).
  • the electrophoretic particles 62A and the electrophoretic particles 62B are charged, and the distribution of the desired electrophoretic particles 62A and electrophoretic particles 62B can be controlled by the electric field and time applied between the pixel electrode 14 and the counter electrode 22. .
  • the migrating particles 62A and 62B are distributed in the light-transmitting porous layer 63A or the porous layer 63B, respectively, or on the display surface S1 side of the light-reflecting porous layer 63C. By approaching, the colors of the migrating particles 62A and the migrating particles 62B are visually recognized from the display surface.
  • the migrating particles 62 ⁇ / b> A and 62 ⁇ / b> B are hidden in the porous layer 73 ⁇ / b> C by moving into the porous layer 63 ⁇ / b> C (back S ⁇ b> 2 side), and diffused light from the porous layer 63 ⁇ / b> C is visually recognized from the display surface. Is done.
  • FIG. 11 shows the change over time of the potential difference with respect to the display surface S1 side on the back surface S2 side as an example of the driving method of the display device 4.
  • FIG. 12 shows the time change of the average distribution position (average movement position) of the migrating particles 62A (red; R) and 62B (black; B) due to the time change of the potential difference with respect to the display surface S1 side on the back surface S2 side shown in FIG. It represents.
  • the electrophoretic particles 62A and 62B are charged positively (+) and have the electrophoretic speed shown in Table 1.
  • the display surface S1 is displayed in white (starting point 0 seconds).
  • the positively charged migrating particles 62A and 62B begin to move toward the display surface S1, and the potential difference is reduced to 0 when the migrating particle 62B having a fast migrating speed reaches the display surface S1.
  • the migrating particles 62A having a low migrating speed are located in the porous layer 63C that is white due to the non-migrating particles, the migrating particles 62A are concealed by the porous layer 63C. Thereby, the display color of the display surface S1 becomes black (B).
  • the migrating particles 62A staying between the display surface S1 and the back surface S2 (in the porous layer 63C) move toward the display surface S1.
  • the migrating particles 62A reach the interface between the porous layer 63A and the porous layer 63B having optical transparency, the potential on the back surface S2 side is reversed and the potential is lowered with respect to the display surface S1, so that the migration speed is high.
  • the migrating particle 62B moves to the back surface S2 side earlier than the migrating particle 62A.
  • the migrating particles 62B When the potential difference is set to 0 when the migrating particles 62B reach the back surface S2, the migrating particles 62B are distributed in the light-reflecting porous layer 63C and are hidden by the porous layer 63C. During this movement, the migrating particle 62A moves toward the back surface S2, but its moving speed is slow, and since the porous layer 63B having light permeability is disposed, the saturation ( Red) is secured. Thereby, the display color of the display surface S1 is red (R). Further, when the potential on the back surface S2 side is lowered with respect to the display surface S1, the migrating particles 62A staying on the porous layer 63B move to the back surface S2 side. If the potential difference is set to 0 when the migrating particles 62A reach the back surface S2, both the migrating particles 62A and 62B are concealed by the porous layer 63C, and the display color is white (W).
  • FIG. 14 shows a change with time of a potential difference with respect to the display surface S1 side on the back surface S2 side as an example of a driving method of a general display device.
  • a general display device includes electrophoretic particles that are colored in red (red electrophoretic particles; R) and electrophoretic particles that are colored black (black electrophoretic particles; B).
  • a porous layer having transparency and a porous layer having light reflectivity are laminated one by one. Both of the two porous layers have pores having a pore diameter through which red electrophoretic particles and black electrophoretic particles can pass.
  • FIGS. 14 and 15 it can be seen that a general display device requires more time for switching the display color than the display device 4 of the present modification. This is because the moving distance of the red migrating particles having a slower moving speed is larger than that of the display device 4. That is, in this modification, a plurality of porous layers are stacked so that the average pore diameter decreases from the back surface S2 toward the display surface S1. Specifically, since the porous layer 63A having a pore diameter equal to or smaller than the average particle diameter of the migrating particles 62A is disposed on the display surface S1, the moving distance of the migrating particles 62A is shortened, and the display speed is increased accordingly. Colors (black (B), red (R), and white (W) in this modification) can be switched.
  • 16A and 16B show the external configuration of an electronic book.
  • the electronic book includes, for example, a display unit 110, a non-display unit 120, and an operation unit 130.
  • the operation unit 130 may be provided on the front surface of the non-display unit 120 as illustrated in FIG. 16A, or may be provided on the upper surface as illustrated in FIG. 16B.
  • the display unit 110 is configured by the display device 1 (or 2, 3).
  • the display device 1 (or the display devices 2 to 4) may be mounted on a PDA (Personal Digital Assistants) having the same configuration as the electronic book shown in FIGS. 16A and 16B.
  • PDA Personal Digital Assistants
  • FIG. 17 shows the appearance of a tablet personal computer.
  • the tablet personal computer has, for example, a touch panel unit 210 and a housing 220, and the touch panel unit 210 is constituted by the display device 1 (or display devices 2 to 4).
  • the display devices 1 to 4 of the above-described embodiments and modifications may be applied to an electronic bulletin board or the like.
  • the embodiment and modifications 1 and 2 have been described, but the present disclosure is not limited to the aspects described in the embodiment and the like, and various modifications are possible.
  • the same number of types of migrating particles 32 having different particle sizes and the same number of types of porous layers 33 having different pore sizes of the pores 333 are used. May be.
  • the porous layers 33 having different pore diameters of the pores 333 may be stacked with a larger number of layers than the types of the migrating particles 32 having different particle diameters.
  • the structure provided with the insulating liquid 31, the electrophoretic particle 32, and the porous layer 33 was illustrated as the electrophoretic element 30 (display layer), the structure of the electrophoretic element 30 is this. It is not limited to the one using the porous layer 33 as long as it can form a contrast by light reflection for each pixel using the electrophoresis phenomenon.
  • the modification 1 may be combined with the modification 2 to charge the porous layer 63, for example.
  • this indication can also take the following structures.
  • a plurality of types of migrating particles having different average particle sizes A display device comprising a plurality of porous layers formed of a fibrous structure and having different average pore diameters.
  • the display device according to (1) including a display surface, wherein the plurality of porous layers are laminated to each other, and an average pore diameter decreases from the display surface toward the back surface.
  • the display device according to (1) or (2), wherein the plurality of types of migrating particles have different colors.
  • the plurality of porous layers have a first layer from the display surface side and a second layer having a smaller average pore diameter than the first layer, The display device according to any one of (2) to (4), wherein the thickness of the first layer is larger than that of the second layer.
  • an average particle diameter of the plurality of types of migrating particles is 100 nm to 2 ⁇ m.
  • the display device according to any one of (1) to (8), wherein an average pore diameter of the plurality of porous layers is 0.1 ⁇ m or more and 5 ⁇ m or less.
  • the porous layer has non-migrating particles held in the fibrous structure, The non-electrophoretic particles have a light reflectance higher than that of the electrophoretic particles, the electrophoretic particles display dark, and the non-electrophoretic particles and the fibrous structure perform bright display.
  • the display apparatus in any one of. (11)
  • the electrophoretic particles and the non-electrophoretic particles are composed of at least one of an organic pigment, an inorganic pigment, a dye, a carbon material, a metal material, a metal oxide, glass, and a polymer material.
  • the plurality of porous layers have a third layer from the display surface side and a fourth layer having a larger average pore diameter than the third layer, The display device according to (12), wherein each of the third layer and the fourth layer has optical transparency.
  • the plurality of porous layers further have a fifth layer on the back side of the fourth layer, The display device according to (13), wherein the fifth layer has an optical reflection characteristic different from that of the plurality of types of migrating particles.
  • the particles that do not reflect visible light are titania (TiO 2 ) having a particle size of 250 nm or less.
  • the fibrous structure is made of an acrylic resin.

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  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
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Abstract

La présente invention concerne un dispositif d'affichage (1) comprenant une pluralité de types de particules migrantes (32) présentant des diamètres de grains moyens différents, et une pluralité de couches poreuses (33) formées avec une structure fibreuse et présentant des diamètres de pores moyens différents.
PCT/JP2016/065974 2015-06-08 2016-05-31 Dispositif d'affichage et appareil électronique WO2016199617A1 (fr)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008286855A (ja) * 2007-05-15 2008-11-27 Fuji Xerox Co Ltd 表示媒体及び表示装置
JP2012093627A (ja) * 2010-10-28 2012-05-17 Seiko Epson Corp 表示シート、表示装置および電子機器
WO2013077163A1 (fr) * 2011-11-22 2013-05-30 ソニー株式会社 Élément électrophorétique, son procédé de fabrication et dispositif d'affichage
WO2014038291A1 (fr) * 2012-09-05 2014-03-13 ソニー株式会社 Élément électrophorétique, dispositif d'affichage et appareil électronique

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008286855A (ja) * 2007-05-15 2008-11-27 Fuji Xerox Co Ltd 表示媒体及び表示装置
JP2012093627A (ja) * 2010-10-28 2012-05-17 Seiko Epson Corp 表示シート、表示装置および電子機器
WO2013077163A1 (fr) * 2011-11-22 2013-05-30 ソニー株式会社 Élément électrophorétique, son procédé de fabrication et dispositif d'affichage
WO2014038291A1 (fr) * 2012-09-05 2014-03-13 ソニー株式会社 Élément électrophorétique, dispositif d'affichage et appareil électronique

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