JP2007140343A - Panel for information display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel for information display whose panel display surface is improved in lightness by increasing a white light convergence rate by using reflected light from particles for white display medium at a maximum. <P>SOLUTION: In the panel for information display in which unite cells partitioned with partition walls 4 forming the unit cells between a display-surface side transparent substrate 2 and a back-side substrate 1 each comprises three pixels and which has transparent color filters 7R, 7G, and 7B of three primary colors (R, G, B) arranged by pixels on the side of the display-surface side transparent substrate 2 and performs color display of information of an image etc., by moving display media 3W and 3B of two colors of white and black charged in air spaces in pixels, the lightness of the panel display surface is improved by making a white light convergence rate high by satisfying Dw(50)/Db(50)=0.1 to 0.8 and Dw(50)=0.1 to 10 (μm), where Dw(50) is the mean particle size of the particles 3Wa for the white display medium and Db(50) is the mean particle size of particles 3Ba for the black display medium. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, each of a plurality of unit cells partitioned by a partition between two substrates is composed of three pixels, and a transparent color filter of three primary colors is arranged for each pixel on the transparent substrate side. An information display panel for displaying information such as images by moving a black and white display medium enclosed between air and voids in a pixel so that the enclosed display medium is not unevenly distributed. The present invention relates to an information display panel provided.

  As a conventional example of an information display panel for displaying information such as images in color, as shown in FIG. 7, two-color black and white display media (particle group or powder fluid) 101W, 101B are used as three primary color transparent color filters 102R, An information display panel (see, for example, Patent Document 1) in which information such as an image is displayed in color by enclosing the air gap in the cell 105 between the substrates 103 and 104 on which the substrates 102G and 102B are respectively arranged, and moving the display medium by an electric field. )

International Publication No. WO2004 / 008239 Pamphlet

  In the conventional information display panel, when white particles and black particles are used as the display medium, the reflected light from the white particles or the reflected light from the black particles is color-combined through the transparent color filters 102R, 102G, and 102B. In this structure, color display is performed, and a colored layer 107 is provided between the top of the partition wall 106 forming the cell and the substrate 103 to increase the black density, but the panel is absorbed by the transparent color filter. There is a problem that the display state of the display surface becomes dark.

  An object of the present invention is to provide an information display panel in which the reflected light from the particles for white display medium is maximally utilized to increase the white light collection rate and the brightness of the panel display surface is improved. .

  In order to achieve the above object, the information display panel according to the first aspect of the present invention is configured such that each of a plurality of unit cells partitioned by a partition between two substrates is composed of three pixels, and each pixel is disposed on a transparent substrate side. In an information display panel in which transparent color filters of the three primary colors are respectively arranged, and a black and white display medium enclosed between the air cavities in the pixels is moved to display information such as images in black and white, When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), Dw (50) /Db(50)=0.1 to 0.8 and Dw (50) = 0.1 to 10 (μm).

  In order to achieve the above object, an information display panel according to a second aspect of the present invention is configured such that each of a plurality of unit cells partitioned by a partition between two substrates is composed of three pixels, and each pixel is disposed on a transparent substrate side. In an information display panel in which transparent color filters of the three primary colors are respectively arranged, and a black and white display medium enclosed between the air cavities in the pixels is moved to display information such as images in black and white, When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), Dw (50) /Db(50)=0.1 to 0.8, and Db (50) = 0.5 to 20 (μm).

  According to the information display panel of the first invention configured as described above, each of the plurality of unit cells partitioned by the partition between the two substrates is composed of three pixels, and each pixel has three primary colors on a transparent substrate. In an information display panel for displaying information such as images by moving a monochrome two-color display medium enclosed between air cavities in pixels each having a transparent color filter of color arranged therein, particles for a monochrome two-color display medium When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), Dw (50) / Db (50) = 0.1 to 0.8 and Dw (50) = 0.1 to 10 (μm), the white display medium is moved to the display surface side of the panel, and the white display medium particles When displaying with reflected light, The adhesion of the black display medium particles to be moved from the display surface side of the panel to the back side of the panel is optimized, and the black display medium particles move without remaining on the display surface side of the panel. Only the white display medium particles are present on the display surface side, the surface area of the white display medium particles existing in the panel display surface is increased, and the reflected light from the white display medium particles is maximized. Therefore, the brightness of the panel display surface is improved. Therefore, an information display panel in which the brightness of the panel display surface is improved can be provided.

  According to the information display panel of the second invention configured as described above, each of the plurality of unit cells partitioned by the partition between the two substrates is composed of three pixels, and each pixel has three primary colors on a transparent substrate. In an information display panel for displaying information such as images by moving a monochrome two-color display medium enclosed between air cavities in pixels each having a transparent color filter of color arranged therein, particles for a monochrome two-color display medium When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), Dw (50) / Db (50) = 0.1 to 0.8 and Db (50) = 0.5 to 20 (μm), the white display medium is moved to the display surface side of the panel, and the white display medium particles When displaying with reflected light, The adhesion of the black display medium particles to be moved from the display surface side of the panel to the back side of the panel is optimized, and the black display medium particles move without remaining on the display surface side of the panel. Only the white display medium particles are present on the display surface side, the surface area of the white display medium particles existing in the panel display surface is increased, and the reflected light from the white display medium particles is maximized. Therefore, the brightness of the panel display surface is improved. Therefore, an information display panel in which the brightness of the panel display surface is improved can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  First, a basic configuration of an information display panel that is an object of the present invention will be described. In the information display panel which is an object of the present invention, an electric field is applied to a display medium sealed between two opposing substrates. Along with the applied electric field direction, the charged display medium is attracted by the electric field force or Coulomb force, etc., and the display medium changes the moving direction by the electric field direction change due to the potential switching, thereby displaying information such as an image. Made. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain stability when rewriting the display repeatedly or when displaying the display information continuously. Here, as the force applied to the particles constituting the display medium, in addition to the force attracting each other by the Coulomb force between the particles, an electric mirror image force between the electrode and the substrate, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

  An example of an information display panel that is an object of the present invention will be described with reference to FIGS.

  In the example shown in FIG. 1, at least two or more types of display media 3 (here, white display particles composed of particles 3Wa for white display media) having different optical reflectivity and charging characteristics composed of at least one type of particles. The black display medium 3B, which is composed of a particle group of the medium 3W and the black display medium particles 3Ba, is moved in a direction perpendicular to the substrates 1 and 2 in accordance with the electric field applied from the outside of the substrates 1 and 2. 3B is visually recognized by the observer and black display is performed, or the white display medium 3W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1, for example, partitions 4 are provided in a lattice shape between the substrates 1 and 2 to form pixels. Moreover, in FIG. 1, the partition in front is abbreviate | omitted.

  In the example shown in FIG. 2, at least two or more types of display media 3 (here, white display particles composed of particles 3Wa for white display media) having different optical reflectance and charging characteristics composed of at least one type of particles. The black display medium 3B including a particle group of the medium 3W and the black display medium particles 3Ba) is generated by applying a voltage between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2. Depending on the electric field, the substrate is moved perpendicularly to the substrates 1 and 2 and the black display medium 3B is visually recognized by the observer to display black, or the white display medium 3W is visually recognized by the observer and white display is performed. Is going. In the example shown in FIG. 2, for example, a partition 4 is provided between the substrates 1 and 2 in a lattice shape to form pixels. Moreover, in FIG. 2, the partition in front is abbreviate | omitted.

  The above description is similarly applied to the case where the white display medium 3W including the particle group is replaced with the white display medium including the powder fluid and the black display medium 3B including the particle group is replaced with the black display medium including the powder fluid. be able to. The powder fluid will be described later.

  A configuration example of the information display panel according to the present invention will be described below with reference to FIGS. The information display panel according to the present invention includes three unit cells each of which is partitioned by a partition wall 4 constituting a unit cell between the display surface side transparent substrate 2 and the back surface side substrate 1, and includes a display surface side transparent substrate. Transparent color filters 7R, 7G, and 7B of three primary colors (R, G, and B) are arranged for each pixel on the second side, and the black and white two-color display media 3W and 3B enclosed between the air and hollow in the pixel are moved. An information display panel for displaying information such as an image in color, which is a change to the information display panel shown in FIGS. 1 and 2 to correspond to the color display of information such as an image (transparent color filter In addition, an “internal electric field driving type (with internal electrodes) information display panel” shown in FIG. 3A and an “external electric field driving type (internal electrode) shown in FIG. 3B” are added. None) Information display panel " There are two types of. In the case of color display, a unit (unit cell) in which three cells having three primary color filters are arranged as one set is a pixel unit, and independent display medium movement is performed for each pixel included in the pixel unit. Thus, color display can be performed by combining three colors obtained through the color filter.

  The color display compatible information display panel shown in FIG. 3A is provided with transparent color filters 7R, 7G, and 7B on the substrate 2 side which is the display surface side transparent substrate of the information display panel shown in FIG. A black matrix (hereinafter referred to as BM) 8 which is a colored layer is provided between the top of the partition wall 4 forming the unit cell and the substrate 2 and between the top of the partition wall 4 forming the pixel and the substrate 2, and will be described later. As described above, by reducing the diameter of the white display medium particles 3Wa to be smaller than the diameter of the black display medium particles 3Ba, the surface area of the white display medium particles existing in the panel display surface is increased, thereby increasing the white display medium particles. It is designed to make the best use of the reflected light from. Similarly, in the color display compatible information display panel shown in FIG. 3B, transparent color filters 7R, 7G, and 7B are provided on the substrate 2 side which is the display surface side transparent substrate of the information display panel shown in FIG. A black matrix (hereinafter referred to as BM) 8 that is a colored layer is provided between the top of the partition wall 4 forming the unit cell and the substrate 2 and between the top of the partition wall 4 forming the pixel and the substrate 2. Further, as described later, by reducing the diameter of the white display medium particles 3Wa to be smaller than the diameter of the black display medium particles 3Ba, the surface area of the white display medium particles existing in the panel display surface is increased to display white. The reflected light from the medium particles is used to the maximum extent.

  Hereinafter, a configuration that uses reflected light from the white display medium particles to the maximum will be described with reference to FIGS. 4 and 5, the configuration in which the reflected light from the particles for the white display medium is used to the maximum is applied to the “information display panel of external electric field drive type (no internal electrode)” in FIG. However, the present invention can be similarly configured when applied to the “information display panel of internal electric field drive type (with internal electrodes)” of FIG.

  In the example shown in FIG. 4, each of a plurality (two in the illustrated example) of unit cells partitioned by partition walls 4 forming unit cells is arranged between the display surface side transparent substrate 2 and the back side substrate 1. It is composed of three pixels partitioned by a partition wall 4 to be formed, and transparent color filters 7R, 7G, 7B of three primary colors (R, G, B) are arranged for each pixel on the inner surface side of the display surface side transparent substrate 2, The white display medium 3W and the black display medium 3B are sealed between the air holes in the pixel, and between the top of the partition wall 4 forming the unit cell and the substrate 2, and between the top of the partition wall 4 forming the pixel and the substrate 2. Is provided with BM8 which is a colored layer. In the illustrated example, the BM 8 is provided between the top of the partition wall 4 and the substrate 2. However, the BM 8 may be omitted.

  In the example shown in FIG. 5, each of a plurality of (two in the illustrated example) unit cells divided by partition walls 4 that form unit cells is arranged between the display surface side transparent substrate 2 and the back side substrate 1. It is composed of three pixels partitioned by partition walls 4 to be formed, and three primary color (R, G, B) transparent color filters 7R, 7G, 7B are arranged for each pixel on the outer surface side of the display surface side transparent substrate 2, The white display medium 3W and the black display medium 3B are sealed between the air holes in the pixel, and between the top of the partition wall 4 forming the unit cell and the substrate 2, and between the top of the partition wall 4 forming the pixel and the substrate 2. Is provided with BM8 which is a colored layer. In the illustrated example, the BM 8 is provided between the top of the partition wall 4 and the substrate 2. However, the BM 8 may be omitted.

  In the present invention, in order to make maximum use of reflected light from the white display medium particles 3Wa, the relationship between the particle diameters of the black and white display medium particles is expressed as follows. (50), and when the average particle diameter of the black display medium particles 3Ba is Db (50), Dw (50) / Db (50) = 0.1 to 0.8. The surface area of the particles 3Wa for white display medium existing inside is larger than the surface area of the particles 3Ba for black display medium existing in the panel display surface. In order to drive the white display medium 3W with small energy, it is important to reduce the adhesion between the white display medium particles 3Wa and the substrate surface, and the average particle diameter Dw ( If 50) is smaller than 0.1 μm, the adhesion between the particles and the substrate becomes large, which may impair the drivability. Therefore, the average particle diameter Dw (50) of the white display medium particles 3Wa is 0. It is preferable to be in the range of 1 to 10 (μm). Further, when it is desired to move the white display medium to the display surface side, sufficient white light reflected by the white display medium particles can be obtained unless the black display medium particles remain on the display surface side. Therefore, it is preferable to reduce the adhesion of the black display medium particles to the substrate so that the mobility of the black display medium particles is higher than the mobility of the white display medium particles. The average particle diameter Db (50) of the particles 3Ba for use is preferably in the range of 0.5 to 20 (μm).

The partition walls 4 that form the unit cells and the partition walls 4 that form the pixels may be incompletely formed by the respective partition walls, even if they are continuous to form unit cells / pixels that are completely surrounded by the respective partition walls. It may be intermittent to form enclosed unit cells / pixels, as long as it has a function of preventing uneven distribution of a display medium and a function of maintaining a gap between substrates at a predetermined size. .
In the relationship between the partition wall 4 that forms the unit cell and the partition wall 4 that forms the pixel, the partition wall 4 that forms the unit cell needs to be provided with an inter-substrate gap maintaining function. It is not necessary to provide the gap maintaining function.

  According to the information display panel of the present invention, each of the unit cells partitioned by the partition walls 4 forming the unit cells between the display surface side transparent substrate 2 and the back surface side substrate 1 is composed of three pixels, and the display surface Black and white two-color display media 3W and 3B are sealed between the air holes in the pixels in which the three primary color (R, G, and B) transparent color filters 7R, 7G, and 7B are arranged on the side transparent substrate 2, respectively. The relationship between the particle diameters of the display medium particles is the average particle diameter Dw (50) of the white display medium particles 3Wa / the average particle diameter Db (50) of the black display medium particles 3Ba = 0.1 to 0.8. And Dw (50) = 0.1 to 10 (μm) and Db (50) = 0.5 to 20 (μm), and particles for white display medium existing in the panel display surface Since the surface area of 3Wa was increased, the white surface Since the reflected light from the display medium particles 3Wa can be utilized to the maximum, the white light collection rate can be increased, so that the brightness of the panel display surface is improved. Therefore, an information display panel in which the brightness of the panel display surface is improved can be provided.

  Hereinafter, each member which comprises the information display panel used as the object of this invention is demonstrated.

  As for the substrate, the display surface side substrate is a transparent substrate on which the color of the display medium can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The back substrate may be transparent or opaque. Examples of the substrate include inorganic substrates such as glass and ceramics, polyethylene terephthalate (PET), polyethylene terephthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), and polyethersulfone (PES). Organic polymer substrates such as acrylic can be used. The thickness of the substrate is preferably from 2 to 5000 μm, more preferably from 5 to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, it will be a thin information display panel. Is inconvenient.

  Electrode forming materials for electrodes provided as necessary include metals such as aluminum, silver, nickel, copper, and gold, conductive metal oxides such as ITO, indium oxide, conductive tin oxide, and conductive zinc oxide, polyaniline , Conductive polymers such as polypyrrole and polythiophene are exemplified, and are appropriately selected and used. The electrode can be formed by patterning the above-described materials into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or by mixing a conductive agent with a solvent or synthetic resin binder. A method of applying and patterning is used. The electrode provided on the viewing side (display surface side) substrate needs to be transparent, but the electrode provided on the back side substrate does not need to be transparent. In any case, the above-mentioned material that is conductive and capable of pattern formation can be suitably used. Note that the electrode thickness is not particularly limited as long as the conductivity can be secured and the light transmittance is not hindered, and is preferably 3 to 1000 nm, preferably 5 to 400 nm. The material and thickness of the electrode provided on the back side substrate are the same as those of the electrode provided on the display surface side substrate described above, but need not be transparent. In this case, the external voltage input may be superimposed with direct current or alternating current.

The shape of the partition provided on the substrate is appropriately set according to the type of display medium involved in display, the shape and arrangement of the electrodes to be arranged, and is not generally limited. However, the width of the partition is 2 to 100 μm, preferably 3 The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm.
In forming the partition wall, a both-rib method in which ribs are formed on each of the opposing substrates 1 and 2 and then bonded, and a single-rib method in which ribs are formed only on one substrate are conceivable. In the present invention, any method is preferably used.
As shown in FIG. 6, the cells formed by the partition walls made up of these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the plane of the substrate. And a mesh shape. It is better to make the portion corresponding to the cross section of the partition wall visible from the display surface side (the area of the cell frame) as small as possible, and the display becomes clearer.
Examples of the method for forming the partition include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Any of these methods can be suitably used for the information display panel of the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.

  Next, the powder fluid used as a display medium in the information display panel of the present invention will be described. As for the name of the powder fluid used in the information display panel of the present invention, the present applicant has obtained the right of “Electronic Powder Fluid (registered trademark): Registration No. 4636931”.

  The “powder fluid” in the present invention is a substance in an intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. For example, liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of liquid and anisotropy (optical properties) that is a characteristic of solid (Heibonsha: Encyclopedia) . On the other hand, the definition of particle is an object with a finite mass even if it is negligible, and is said to be affected by gravity (Maruzen: Physics Encyclopedia). Here, even in the case of particles, there are special states of gas-solid fluidized bed and liquid-solid fluids. When gas is flowed from the bottom plate to the particles, upward force is applied to the particles according to the velocity of the gas. Is a gas-solid fluidized bed that is in a state where it can easily flow when it balances with gravity, and it is also called a liquid-solid fluidized state that is fluidized by a fluid (ordinary) Company: Encyclopedia). As described above, the gas-solid fluidized bed body and the liquid-solid fluid are in a state of using a gas or liquid flow. In the present invention, it has been found that a substance in a state of fluidity can be produced specifically without borrowing the force of such gas and liquid, and this is defined as powder fluid.

  That is, the pulverulent fluid in the present invention is in an intermediate state having both the characteristics of particles and liquid, as in the definition of liquid crystal (liquid and solid intermediate phase), and is the characteristic of the above-mentioned particles. It is a substance that is extremely unaffected and exhibits a unique state with high fluidity. Such a substance can be obtained in an aerosol state, that is, in a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is regarded as a dispersoid in the information display panel of the present invention. To do.

The information display panel of the present invention encloses a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, in a gas, between opposed substrates, at least one of which is transparent. In addition, such a powder fluid can be easily and stably moved by a Coulomb force or the like with a small electric field.
As described above, the pulverized fluid used in the present invention is a substance in the intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. This powder fluid can be in an aerosol state in particular, and in the information display panel of the present invention, it is used as a display medium in a state where a solid substance floats relatively stably as a dispersoid in the gas.

Next, display medium particles (hereinafter also referred to as particles) constituting the display medium in the information display panel of the present invention will be described. The display medium particles are composed of the display medium particles as they are to form a display medium, or are combined with other particles to form a display medium, or adjusted and configured to become a powder fluid to form a display medium. Or used.
The particles can contain a charge control agent, a colorant, an inorganic additive, and the like, if necessary, in the resin as the main component, as in the conventional case. Examples of resins, charge control agents, colorants, and other additives will be given below.

  Examples of the resin include urethane resin, urea resin, acrylic resin, polyester resin, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene resin, styrene Acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin and the like can be mentioned, and two or more kinds can be mixed. In particular, acrylic urethane resin, acrylic silicone resin, acrylic fluororesin, acrylic urethane silicone resin, acrylic urethane fluororesin, fluororesin, and silicone resin are suitable from the viewpoint of controlling the adhesive force with the substrate.

  The charge control agent is not particularly limited. Examples of the negative charge control agent include salicylic acid metal complexes, metal-containing azo dyes, metal-containing oil-soluble dyes (including metal ions and metal atoms), and quaternary ammonium salt systems. Examples thereof include compounds, calixarene compounds, boron-containing compounds (benzyl acid boron complexes), and nitroimidazole derivatives. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane compounds, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and the like. In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

  As the colorant, various organic or inorganic pigments and dyes as exemplified below can be used.

Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon and the like.
Examples of blue colorants include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chlorides, Fast Sky Blue, Indanthrene Blue BC, and the like.
Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment Red 2 etc.

Yellow colorants include chrome yellow, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment Yellow 12 etc.
Examples of green colorants include chrome green, chromium oxide, pigment green B, C.I. I. Pigment Green 7, Malachite Green Lake, Final Yellow Green G, etc.
Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment Orange 31 etc.
Examples of purple colorants include manganese purple, first violet B, and methyl violet lake.
Examples of white colorants include zinc white, titanium oxide, antimony white, and zinc sulfide.

  Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Examples of various dyes such as basic, acidic, disperse, and direct dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

Examples of inorganic additives include titanium oxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, Examples include bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.
These pigments and inorganic additives can be used alone or in combination. In addition, it is possible to produce white display medium particles and black display medium particles constituting the display medium used in the present invention by combining a plurality of the above-described additives. Of these, white pigments such as titanium oxide are preferably used for the white display medium particles, and black pigments such as carbon black are preferably used for the black display medium particles.

  The particles for display media of the present invention (hereinafter also referred to as particles) preferably have an average particle diameter d (0.5) in the range of 0.1 to 20 μm and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear, and if it is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the display medium.

Furthermore, in the present invention, regarding the particle size distribution of each particle, the particle size distribution Span represented by the following formula is less than 5, preferably less than 3.
Span = (d (0.9) −d (0.1)) / d (0.5)
(However, d (0.5) is a numerical value expressing the particle diameter in μm that 50% of the particles are larger than this and 50% is smaller than this, and d (0.1) is a particle in which the ratio of the smaller particles is 10%. (Numerical value expressed in μm, and d (0.9) is a numerical value expressed in μm for a particle diameter of 90% or less.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and uniform display medium movement becomes possible.

  Furthermore, regarding the correlation between the particles, the ratio of d (0.5) of the particles having the minimum diameter to d (0.5) of the particles having the maximum diameter among the used particles is set to 50 or less, preferably 10 or less. It is essential. Even if the particle size distribution Span is reduced, particles with different charging characteristics move in opposite directions, so that the particle size is close to each other and each particle can be easily moved in the opposite direction by the equivalent amount. This is within this range.

The particle size distribution and the particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated onto particles to be measured, a light intensity distribution pattern of diffracted / scattered light is spatially generated, and this light intensity pattern has a corresponding relationship with the particle diameter, so that the particle diameter and particle diameter distribution can be measured. .
Here, the particle size and particle size distribution in the present invention are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, put particles into a nitrogen stream and use the attached analysis software (software based on volume-based distribution using Mie theory). The diameter and particle size distribution can be measured.

Furthermore, when applying a display medium such as a particle group composed of particles for a display medium or a powdered fluid to a dry information display panel, it is important to manage the gas in the void surrounding the display medium between the substrates, Contributes to improved display stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, and preferably 50% RH or less for the humidity of the gas in the gap.
1, 2, 3 (a) and (b), electrodes 5 and 6 (when electrodes are provided inside the substrate) from the portion sandwiched between the opposing substrate 1 and substrate 2 in FIG. ), A gas portion in contact with a so-called display medium excluding an occupied portion of the display medium 3, an occupied portion of the partition wall 4, and a seal portion of the information display panel.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in an information display panel so that the humidity is maintained, for example, filling a display medium, assembling an information display panel in a predetermined humidity environment, It is important to apply a sealing material and a sealing method that prevent moisture from entering from the outside.

The distance between the substrates in the information display panel that is the subject of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the display medium in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. When it exceeds 70%, the movement of the display medium is hindered, and when it is less than 5%, the contrast tends to be unclear.

  The information display panel of the present invention has no image unevenness, display parts of mobile devices such as notebook computers, PDAs, mobile phones and handy terminals, electronic papers such as electronic books and electronic newspapers, bulletin boards such as signboards, posters and blackboards. Suitable for display units for calculators, home appliances, automotive products, card display units such as point cards and IC cards, electronic advertisements, electronic POPs, electronic shelf labels, electronic price tags, electronic musical scores, and display units for RF-ID devices Used for.

It is a figure which shows an example of the information display panel used as the object of this invention. It is a figure which shows the other example of the information display panel used as the object of this invention. (A), (b) is a figure which shows the structural example of the information display panel of the color display correspondence type of this invention. It is a figure which shows the 1st example of the structure which utilizes the reflected light from the particle | grains for white display media of the information display panel of this invention to the maximum. It is a figure which shows the 2nd example of the structure which utilizes the reflected light from the particle | grains for white display media of the information display panel of this invention to the maximum. It is a figure which shows an example of the shape of the partition in the information display panel used as the object of this invention. It is a figure which shows the structure of the color display corresponding | compatible information display panel of a prior art example.

Explanation of symbols

1 Substrate (Back side substrate)
2 Substrate (Display side transparent substrate)
3 Display media (particle group, powder fluid)
3W White display medium 3B Black display medium 3Wa White display medium particles 3Ba Black display medium particles 4 Partition 5 Electrode 6 Electrode 7R, 7G, 7B Transparent color filter 8 Colored layer (black matrix; BM)

Claims (2)

Each of the plurality of unit cells partitioned by the partition between the two substrates is composed of three pixels, and a transparent color filter of the three primary colors is arranged for each pixel on the transparent substrate side. In an information display panel for displaying information such as images in color by moving a black and white two-color display medium enclosed between air and air,
When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), (50) / Db (50) = 0.1 to 0.8 and Dw (50) = 0.1 to 10 (μm). Each of the plurality of unit cells partitioned by the partition between the two substrates is composed of three pixels, and a transparent color filter of the three primary colors is arranged for each pixel on the transparent substrate side. In an information display panel for displaying information such as images in color by moving a black and white two-color display medium enclosed between air and air,
When the average particle diameter of the white display medium particles is Dw (50) and the average particle diameter of the black display medium particles is Db (50), (50) / Db (50) = 0.1 to 0.8 and Db (50) = 0.5 to 20 (μm).

Images