JP2007156444A - Panel for information display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel for information display which facilitates manufacturing processes and is low-cost even when color display using a color filter is performed. <P>SOLUTION: The panel for information display that is constituted by charging at least one or more kinds of display media 3 made of at least one or more kinds of particles and having an optical reflection factor and charging property in cells (each corresponding to one display unit) formed by a partition wall 4 between two substrates 1 and 2 at lest one of which is transparent and moves the display media by applying an electric field to the display media to display information of an image etc., is characterized in that the display-side transparent substrate is provided with the color filter 27 constituted by arranging filters of a specified number of colors and a black layer 31 is provided between the partition wall 4 and the display-side transparent substrate 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, a cell (corresponding to one display unit) formed by a partition wall between two substrates, at least one of which is transparent, is composed of at least one kind of particles, and has an optical reflectance and chargeability. The present invention relates to an information display panel that displays at least one type of medium and displays information such as an image by moving the display medium by applying an electric field to the display medium.

  2. Description of the Related Art Conventionally, information display devices using techniques such as an electrophoresis method, an electrochromic method, a thermal method, and a two-color particle rotation method have been proposed as information display devices that replace liquid crystal display devices (LCDs).

  Compared to LCDs, these conventional technologies have advantages such as a wide viewing angle close to that of ordinary printed materials, low power consumption, and a memory function. It is considered as a technology that can be used for mobile phones, and is expected to expand to information display for mobile terminals, electronic paper, and the like. Particularly recently, an electrophoretic method in which a dispersion liquid composed of dispersed particles and a solution is encapsulated and disposed between opposing substrates has been proposed and is expected.

  However, the electrophoresis method has a problem that the response speed becomes slow due to the viscous resistance of the liquid because the particles migrate in the liquid. In addition, since particles with high specific gravity such as titanium oxide are dispersed in a solution with low specific gravity, it is easy to settle, and it is difficult to maintain the stability of the dispersed state, and there is a problem that the stability of repeated information display is lacking. ing. Even when microencapsulation is performed, the cell size is set to the microcapsule level, and the above-described drawbacks are hardly made to appear, and the essential problems are not solved at all.

  On the other hand, a method in which conductive particles and a charge transport layer are incorporated into a part of a substrate without using a solution is proposed instead of an electrophoresis method using behavior in a solution (see, for example, Non-Patent Document 1). ). However, the structure is complicated because the charge transport layer and further the charge generation layer are arranged, and it is difficult to inject the charge into the conductive particles at a constant rate, so that the stability in rewriting display information is lacking. There is also.

As one method for solving the various problems described above, a cell that is isolated from each other by a partition wall is formed after sealing a display medium between two opposing substrates, at least one of which is transparent. 2. Description of the Related Art An information display panel that displays information such as an image by applying an electric field to a display medium after the display medium is sealed therein and moving the display medium is known.
趙 Kuniaki and three others, “New Toner Display Device (I)”, July 21, 1999, Annual Meeting of the Imaging Society of Japan (83 times in total) “Japan Hardcopy'99” Proceedings, p.249-252

  In the conventional information display panel described above, in order to perform color display, it is conceivable to use, for example, a white and black display medium and a color filter configured by arranging filters of a predetermined number of colors. For example, a color filter 51 composed of commonly used red (R), green (G), and blue (B) filters has a red filter 51R, a green filter 51G, and a blue filter 51B as shown in FIG. 1 constitutes one display unit 52. A black black matrix 53 is formed between the filters in order to improve the contrast of the display color. For this reason, the conventional color filter 51 having the above-described configuration requires a process of forming the black matrix 53 between the filters, which complicates the manufacturing process and increases the cost.

  An object of the present invention is to solve the above-described problems and to provide an information display panel that can simplify the manufacturing process and does not cost even when performing color display using a color filter. is there.

  The information display panel of the present invention comprises at least one kind of particles in a cell (corresponding to one display unit) formed by a partition between two substrates, at least one of which is transparent, and has an optical reflectance and In an information display panel that displays information such as images by enclosing at least one type of display medium having charging properties and applying an electric field to the display medium, the display medium is provided with a transparent substrate on the display side. In addition, a color filter configured by arranging filters having a predetermined number of colors is provided for color display, and a black layer is provided between the partition wall and the transparent substrate on the display side.

  As a preferred example of the information display panel of the present invention, the color filter is configured by arranging three primary color filters, one display unit is configured by a set of three primary color filters, and the color filter is configured by arranging three primary color filters. One display unit is composed of a set of three primary color filters and a transparent filter, and the three primary color filters are red (R), green (G), and blue (B) filters, and the three primary color filters are used. , Cyan (C), magenta (M), yellow (Y) filter, at least one kind of particles encapsulated in the cell, and having optical reflectivity and chargeability, at least one kind The display medium may be two types of display media, a white display medium and a black display medium.

  According to the present invention, a color filter configured by arranging filters of a predetermined number of colors is provided for color display, and a black layer is provided between the partition wall and the transparent substrate on the display side, thereby providing color display. In addition, in the color display, the black layer can be visually observed so as to surround each pixel, and the same effect as the conventional black matrix can be obtained. This black layer can be formed by laminating at the time of forming the partition wall, and the manufacturing process can be simplified, and an information display panel that does not cost can be obtained.

  First, the basic configuration of the information display panel 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. In accordance with the applied electric field direction, the charged display medium is attracted by the electric field force or the Coulomb force, and the display medium is moved by the change in the electric field direction, whereby information such as an image is displayed. 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.

  The basic structure of the information display panel of the present invention will be described with reference to FIGS. 1 (a) and 1 (b) to FIG.

In the example shown in FIGS. 1A and 1B, at least two types of display media 3 (here, the display white particles 3Wa) having different optical reflectance and charging characteristics composed of at least one type of particles are used. A white display medium 3W made of a particle group and a black display medium 3B made of a particle group of black particles for display 3Ba), each of the cells formed by the partition walls 4, and electrodes 5 (individual electrodes) provided on the substrate 1; The substrate is moved perpendicularly to the substrates 1 and 2 in accordance with an electric field generated by applying a voltage between the electrodes 6 (individual electrodes) provided on the substrate 2. Then, the white display medium 3W is visually recognized by the observer as shown in FIG. 1A, or white display is performed, or the black display medium 3B is visually recognized by the observer as shown in FIG. The display is black. In addition, in FIG. 1 (a), (b), the partition in front is abbreviate | omitted. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate. In the case where a color filter is provided, an example in which a cell is formed for each corresponding color filter, where one cell is formed by combining the three cells shown in the figure and each of the RGB color filters or CMY filters It is.
The examples shown in FIGS. 2A and 2B are obtained by removing the inner partition of one display unit from the examples shown in FIGS. 1A and 1B. In the case where a color filter is provided, the cell is formed by the partition 4 for each display unit configured in combination with the color filter.

In the example shown in FIGS. 3A and 3B, at least two or more types of display media 3 (here, display white particles 3Wa) having different optical reflectance and charging characteristics composed of at least one type of particles are used. A white display medium 3W made of a particle group and a black display medium 3B made of a particle group of display black particles 3Ba), each of the cells formed by the partition walls 4, and the electrode 5 (line electrode) provided on the substrate 1; The substrate 6 is moved perpendicularly to the substrates 1 and 2 according to an electric field generated by applying a voltage between the electrodes 6 (line electrodes) provided on the substrate 2. Then, the white display medium 3W is visually recognized by the observer as shown in FIG. 3A, or white display is performed, or the black display medium 3B is visually recognized by the observer as shown in FIG. 3B. The display is black. In addition, in FIG. 3 (a), (b), the partition in front is abbreviate | omitted. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate. In the case where a color filter is provided, an example in which a cell is formed for each corresponding color filter, where one display unit is a combination of the three cells shown in the figure and each of the RGB color filters or CMY filters. It is.
The example shown in FIGS. 4A and 4B is obtained by removing the inner partition of one display unit from the example shown in FIGS. 3A and 3B. In the case where a color filter is provided, the cell is formed by the partition 4 for each display unit configured in combination with the color filter.

In the example shown in FIGS. 5A and 5B, the display medium 3 (here, a group of particles of white particles for display 3Wa) having at least an optical reflectance and a charging property composed of at least one kind of particles. A white display medium 3W) in each cell formed by the partition walls 4, in accordance with the electric field generated by applying a voltage between the electrode 5 and the electrode 6 provided on the substrate 1, the substrates 1, 2 And move in the direction parallel to Then, as shown in FIG. 5 (a), the white display medium 3W is visually recognized by the observer to display white, or as shown in FIG. 5 (b), the color of the black plate 7B is changed to the observer. Is displayed in black. In addition, in the example shown to Fig.5 (a), (b), the partition in front is abbreviate | omitted. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate. In the case where a color filter is provided, an example in which a cell is formed for each corresponding color filter, where one display unit is a combination of the three cells shown in the figure and each of the RGB color filters or CMY filters. It is.
The example shown in FIGS. 6A and 6B is the same as the example shown in FIGS. 5A and 5B except that the white display medium 3W is replaced with the black display medium 3B and the black plate 7B is replaced with the white plate 7W. Is to be displayed.

  In the example shown in FIGS. 7A to 7D, first, as shown in FIGS. 7A and 7C, at least the optical reflectivity and charging characteristics of at least one kind of particles are different. Two or more kinds of display media 3 (here, a white display medium 3W composed of a group of particles of display white particles 3Wa and a black display medium 3B composed of a group of particles of display black particles 3Ba are shown) are formed of partition walls 4. In each cell, the substrates 1 and 2 correspond to the electric field generated by applying a voltage between the external electric field forming means 11 provided outside the substrate 1 and the external electric field forming means 12 provided outside the substrate 2. And move vertically. Then, the white display medium 3W is visually recognized by the observer as shown in FIG. 7B, or white display is performed, or the black display medium 3B is visually recognized by the observer as shown in FIG. 7D. The display is black. 7A to 7D, the front partition is omitted. In addition, a conductive member 13 is provided inside the substrate 1, and a conductive member 14 is provided inside the substrate 2. This conductive member may not be provided. In the case where a color filter is provided, an example in which a cell is formed for each corresponding color filter, where one display unit is a combination of the three cells shown in the figure and each of the RGB color filters or CMY filters. It is.

  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. I can do it. The powder fluid will be described later.

  In the example shown in FIGS. 8 and 9, another example in which black and white display is performed using the line electrodes 5 and 6 is described as in the example shown in FIG. In the example shown in FIG. 8, the white display medium 3 </ b> W and the black display medium 3 </ b> B together with the insulating liquid 8 are used instead of the cells formed by the partition walls 4 filled with the white display medium 3 </ b> W and the black display medium 3 </ b> B shown in FIG. The microcapsule 9 filled inside is used. Further, in the example shown in FIG. 9, instead of the cells formed of the partition walls 4 filled with the white display medium 3W and the black display medium 3B shown in FIG. A microcapsule 9 filled with an insulating liquid 8 together with a rotating ball 10 configured in the opposite direction as a display medium is used. Each of the examples shown in FIGS. 8 and 9 can perform black and white display similarly to the example shown in FIG. 4, and when three microcapsules and a color filter are provided, they are configured in combination with the color filter. This is an example in which cells are formed by partition walls 4 for each display unit. Note that the height of the partition provided in one display unit can be shorter than the substrate gap.

  10 (a) and 10 (b) are diagrams showing the structure of an example of the information display panel of the present invention, and FIG. 10 (b) shows a cross section taken along the line AA in FIG. 10 (a). ing. In the example shown in FIGS. 10A and 10B, the same members as those in FIGS. 1A and 1B to FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted. Of the examples shown in FIGS. 10A and 10B, the basic configuration is different from the examples shown in FIGS. 1A and 1B to FIG. It is composed of electrodes 6R, 6G, 6B corresponding to blue, and one cell is displayed in one display unit. In addition, it is preferable that the width of the color filter is at least larger than the electrode width, and the width of the adjacent color filter is larger than the average particle diameter of the display medium particles and does not overlap. When the width of the color filter is smaller than the electrode width, the color purity is lowered, and when the overlapping width of the color filter is larger than the average particle diameter of the display medium particles, the brightness is lowered.

  In this example, in addition to the above-described configuration, a flat color filter 27 in which red, green, and blue filters 27R, 27G, and 27B are arranged inside a transparent display-side substrate 2 via a transparent layer. And a black layer 31 is provided between the partition wall 4 and the transparent substrate 2 on the display side. One display unit is composed of a set of red, green, and blue filters 27R, 27G, and 27B. The one set of red, green, and blue filters 27R, 27G, and 27B can also be configured by one set of cyan, magenta, and yellow filters.

  Therefore, in this example, by moving the white display medium 3W to each of the transparent electrodes 6R, 6G, and 6B on the display side for display, the color of each color can be visually recognized through the color filter 27, and a predetermined color display is performed. Is possible. In addition, by visually recognizing the black layer 31 provided between the partition wall 4 and the transparent substrate 2 through the transparent portion of the color filter 27, a black frame is formed around the cells constituting one display unit. It can be visually recognized, and the same effect as a conventional black matrix can be obtained. As a result, the display color contrast can be maintained satisfactorily.

  In the above-described example, the color filter 27 is provided inside the substrate 2, but the present invention is not limited to this. In the above example, the electrodes 5 and 6 are directly exposed, but a transparent protective layer can be provided on the surface of the color filter 27. Furthermore, in the above-described example, the electrodes 5 and 6 are provided in the innermost part, but the color filter 27 can be provided in the innermost part. In that case, a transparent protective layer can be provided on the color filter 27. . Furthermore, in the example described above, the color configuration of the color filter 27 is red, green, blue, cyan, magenta, or yellow, but the present invention is not limited to this.

  FIG. 11 and FIG. 12 are diagrams for explaining the structure of another example of the information display panel of the present invention. In the example shown in FIGS. 11 and 12, the same members as those in FIGS. 10A and 10B are denoted by the same reference numerals, and the description thereof is omitted. In the example shown in FIGS. 11 and 12, the difference from the example shown in FIGS. 10A and 10B is the configuration of the color filter 27, in which a transparent filter 27T is provided as a filter constituting one display unit. It is. The arrangement of the red, green, and blue filters 27R, 27G, and 27B and the transparent filter 27T is not limited to the examples shown in FIGS.

  That is, in the example shown in FIG. 11, in addition to the red, green, and blue filters 27R, 27G, and 27B, one transparent filter 27T is arranged through a transparent layer to form the color filter 27, and one display unit is one set. Red, green and blue filters 27R, 27G and 27B and one transparent filter 27T. In the example shown in FIG. 12, in addition to the red, green, and blue filters 27R, 27G, and 27B, three transparent filters 27T are arranged through a transparent layer to form the color filter 27, and one display unit is one set. Red, green and blue filters 27R, 27G and 27B and three transparent filters 27T. Note that the red, green, and blue filters 27R, 27G, and 27B can be formed of cyan, magenta, and yellow filters.

  As in the example shown in FIGS. 11 and 12, by providing the transparent filter 27T as a filter constituting one display unit, the white display medium 3W is moved and displayed in this portion, thereby brightening the color of the color display. can do. The brightness increases according to the number of the transparent filters 27T. When the example of FIG. 11 is compared with the example of FIG. 12, the example of FIG. 12 can display brighter than the example of FIG. In particular, the display medium is sealed in a cell (corresponding to one display unit) formed by a partition wall between two substrates, at least one of which is an object of the present invention, and an electric field is applied to the display medium. By providing, it is effective as one solution to the problem that it is difficult to increase the conventionally known brightness in an information display panel that displays information such as an image by moving the display medium.

  FIGS. 13A to 13C are diagrams showing the relationship between color filters and electrodes in the information display panel according to the present invention. In the example shown in FIG. 13A, three upper ITO electrodes 6 are provided in the vertical direction corresponding to one set of red, green, and blue filters 27R, 27G, and 27B, and one in the horizontal direction. The lower ITO electrode 5 is provided. In the example shown in FIG. 13 (b), the vertical direction corresponds to four filters arranged in 2 × 2 consisting of a pair of red, green, and blue filters 27R, 27G, and 27B and one transparent filter 27T. Are provided with two upper ITO electrodes 6 and two lower ITO electrodes 5 in the lateral direction. In the example shown in FIG. 13 (c), the vertical direction corresponds to six filters arranged in a 2 × 3 configuration including a pair of red, green, and blue filters 27R, 27G, and 27B and three transparent filters 27T. Are provided with three upper ITO electrodes 6 and a lower ITO electrode 5 in the lateral direction.

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

  As for the substrate, at least one substrate is the transparent substrate 2 from which the color of the display medium 3 can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The substrate 1 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and glass and quartz. An inorganic sheet having no flexibility is mentioned. 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.

  The electrodes and conductive member forming materials provided as necessary include metals such as aluminum, silver, nickel, copper, and gold, indium tin oxide (ITO), antimony tin oxide (ATO), indium oxide, and conductive oxide. Examples include conductive metal oxides such as tin and conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene, which are appropriately selected and used. As a method for forming the electrode and the conductive member, a method of patterning the above exemplified materials into a thin film by a sputtering method, a vacuum deposition method, a CVD (chemical vapor deposition) method, a coating method, etc., a conductive agent as a solvent or a synthetic resin binder A method of forming a pattern by mixing and coating is used. The electrodes and conductive members provided on the viewing side (display surface side) substrate need to be transparent, but the electrodes and conductive members provided on the back side substrate do not need to be transparent. In any case, the above-mentioned material that is conductive and capable of pattern formation can be suitably used. The thickness of the electrode and the conductive member 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 materials and thicknesses of the electrodes and conductive members provided on the back side substrate are the same as those of the electrodes and conductive members 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 walls 4 provided on the substrate is optimally set as appropriate depending on the type of display medium involved in display, the shape and arrangement of electrodes to be arranged, and is not limited in general, but the width of the partition walls is 2 to 100 μm, preferably The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm, to 3 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. 14, 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 opposing substrates, at least one of which is transparent. Yes, such pulverulent fluid is so fluid that it cannot measure the angle of repose, which is an index indicating the fluidity of the powder, and it can be easily and stably moved by Coulomb force with a small electric field force. Can do.
As described above, for example, the powder fluid used as a display medium in the present invention is a substance in an intermediate state between fluid and particles that exhibits fluidity by itself without borrowing the force of gas or liquid. It is. 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. Of these, carbon black is particularly preferable as the black pigment, and titanium oxide is preferable as the white pigment.
By blending the colorant, particles for a display medium having a desired color can be produced.

  The particles for display medium of the present invention (hereinafter also referred to as particles) preferably have an average particle diameter d (0.5) in the range of 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.

  The charge amount of the display medium particles naturally depends on the measurement conditions, but the charge amount of the display medium particles in the information display panel is almost the same as the initial charge amount, the contact with the partition walls, the contact with the substrate, and the elapsed time. It was found that depending on the charge decay, the saturation value of the charging behavior of the particles for the display medium is a dominant factor.

  As a result of intensive studies, the present inventors have been able to evaluate the range of proper charging characteristics of display medium particles by measuring the charge amount of the particles used in the display medium using the same carrier particles in the blow-off method. I found.

Furthermore, when the display medium is applied to a dry information display panel that is driven in an air space, it is important to manage the gas in the gap surrounding the display medium between the substrates, which 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.
For example, in FIG. 1 (a), (b) to FIG. 9, the gap portion is defined by electrodes 5 and 6 (when the electrode is provided inside the substrate) from the portion sandwiched between the opposing substrate 1 and substrate 2. 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 is meant.
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 air 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 is a display unit for mobile devices such as notebook computers, PDAs, mobile phones, handy terminals, electronic paper such as electronic books, electronic newspapers, and electronic manuals (instruction manuals), signs, posters, and blackboards. Bulletin boards, calculators, home appliances, automotive parts, card displays such as point cards, IC cards, electronic advertising, electronic point of purchase (POP), electronic price tags, electronic shelf labels, In addition to the electronic musical score and the display unit of the RF-ID device, it is also suitably used as a rewritable paper for driving a display medium using external electric field forming means.

  As for the method for driving the information display panel of the present invention, a simple matrix driving method and a static driving method that do not use a switching element in the panel itself, and an active that uses a two-terminal switching element represented by a thin film transistor (TFT). Various types of driving methods such as a driving method and an external electric field driving method using an external electric field forming means can be applied.

(A), (b) is a figure which shows an example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the other example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. (A)-(d) is a figure which shows the further another example of the information display panel of this invention, respectively. It is a figure which shows the further another example of the information display panel of this invention. It is a figure which shows the further another example of the information display panel of this invention. (A), (b) is a figure which shows the structure of an example of the information display panel of this invention, respectively. It is a figure which shows the other example of the color filter used for the information display panel of this invention. It is a figure which shows the further another example of the color filter used for the information display panel of this invention. (A)-(c) is a figure which shows the relationship between the color filter and electrode in the information display panel of this invention, respectively. It is a figure which shows an example of the shape of the partition in the information display panel of this invention. It is a figure for demonstrating an example of the color filter used for the conventional information display panel.

Explanation of symbols

1, 2 Substrate 3 Display medium (particle group, powder fluid)
3W White display medium 3Wa White display medium particle 3B Black display medium 3Ba Black display medium particle 4 Bulkhead 5, 6, 6R, 6G, 6B Electrode 7B Black plate 7W White plate 8 Insulating liquid 9 Microcapsule 10 Rotating ball 11, 12 External electric field forming means 13, 14 Conductive member 27 Color filter 27R, 27G, 27B, 27T Filter 31 Black layer

Claims (6)

  A cell (corresponding to one display unit) formed by a partition wall between two substrates, at least one of which is transparent, is composed of at least one kind of particles, and has at least one display medium having optical reflectivity and chargeability. In an information display panel that displays information such as images by moving the display medium by enclosing more than one type and applying an electric field to the display medium, filters with a predetermined number of colors are arranged on a transparent substrate on the display side An information display panel characterized in that a color layer is provided for color display and a black layer is provided between a partition wall and a transparent substrate on the display side.   2. The information display panel according to claim 1, wherein the color filter is configured by arranging filters of three primary colors, and one display unit is configured by a set of filters of the three primary colors.   2. The information display panel according to claim 1, wherein the color filter is configured by arranging filters of three primary colors, and one display unit is configured by a set of filters of three primary colors and a transparent filter.   4. The information display panel according to claim 2, wherein red (R), green (G), and blue (B) filters are used as the three primary color filters.   4. The information display panel according to claim 2, wherein cyan (C), magenta (M), and yellow (Y) filters are used as the three primary color filters.   At least one type of display medium comprising at least one type of particles enclosed in the cell and having optical reflectivity and chargeability is two types of display media, a white display medium and a black display medium. The information display panel according to claim 1, wherein:

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