JP2005250136A - Panel for image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel for image display which allows a lead wire part to be hidden even in segment display and allows a color of a background to be freely changed. <P>SOLUTION: The panel for image display has a structure wherein a first substrate having electrode parts 5 and 6 formed on a surface thereof and a second substrate having electrode parts and partitions 4 for demarcating display cells formed on a surface thereof, which are opposed to each other and at least one of which is transparent, are put one over the other so that respective electrode parts face each other and particle groups or a particulate material 3 are sealed between these substrates, and at least electrodes on at least one substrate are arranged like segments to perform segment display, and lead wire parts 13-1 to 13-7 and 16-1 to 16-7 for electrically connecting electrode parts 11 (14) and electric signal input parts 12 (15) of the first and second substrates 1 and 2 are arranged between the substrates 1 and 2 and the partitions 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a first substrate having at least one transparent substrate, the first substrate having an electrode portion formed on the surface, and the second substrate having an electrode portion formed on the surface and a partition defining a display cell. Display panel for displaying a segment by arranging at least one of the electrode portions in a segment shape, wherein the electrode portions are stacked so that the electrode portions face each other, and a particle group or powder fluid is sealed therebetween It is about.

  2. Description of the Related Art Conventionally, image 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 image display devices that can replace liquid crystal (LCD).

  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 image 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 colored 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. Furthermore, 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 of lack of image repetition stability. . 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 charges into the conductive particles.

As a method for solving the various problems described above, a cell isolated from each other by a partition is formed between a front substrate and a rear substrate, and a particle group or a powder fluid is enclosed in the cell. 2. Description of the Related Art An image display device including an image display panel that displays an image by applying an electric field to a fluid and moving particles or powdered fluid by Coulomb force or the like is known.
趙 Kuniori 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

  Some of the image display panels described above perform segment display by arranging electrode portions on opposite substrates in a segment shape. In an image display panel that performs this type of segment display, for example, a conductive wire that electrically connects an electrode portion on a glass substrate patterned for segment display to an electric signal input portion provided at an end portion of the glass substrate. Even if it is a portion, it is driven when a voltage is applied, and there is a problem that even if the background is white display, the lead wire portion is displayed as a black line. In order to avoid this, it is also conceivable that only the segment part is filled with the particle group or the powder fluid and the background part is not filled. However, in this case, since there is no particle group or powder fluid in the background portion, there is a problem that black characters cannot be displayed on a white background and white characters cannot be displayed on a single panel.

  An object of the present invention is to solve the above-described problems and to provide an image display panel that can hide a conductor portion even in segment display and can freely change the color of a background portion.

  The image display panel of the present invention is a first substrate having an electrode portion formed on the surface and a partition wall defining the display cell, at least one of which is a transparent opposing substrate. The second substrate is overlapped so that the electrode portions face each other, and a particle group or powder fluid is sealed therebetween, and at least one of the electrode portions is arranged in a segment to display a segment display. In the image display panel to be performed, in each of the first substrate and the second substrate, a conductive wire portion that electrically connects the electrode portion and the electric signal input portion is disposed between each substrate and the partition wall. It is a feature.

  In a preferred example of the image display panel of the present invention, a partition other than the partition defining the display cell is formed in advance in a portion other than the portion for performing the segment display, and the partition between the partition and each substrate is formed. A conducting wire part can be arranged in

  According to the present invention, in an image display panel that performs segment display using particle groups or powdered fluid, the structure is such that the particle groups or powdered fluid is not placed on the conductor parts by overlapping the conductor parts on the partition walls. In addition, it is possible to drive so that the conductor portion is not visible during segment display, and it is possible to display black on a white background and white on a black character.

  First, the basic configuration of the image display panel of the present invention will be described. In the image display panel of the present invention, an electric field is applied to a particle group or powder fluid sealed between two opposing substrates. Along the applied electric field direction, particles or powder fluid charged at a low potential toward the high potential side is attracted by Coulomb force, and particles charged at a high potential toward the low potential side. Alternatively, the powder fluid is attracted by Coulomb force or the like, and the particle group or the powder fluid reciprocates due to the change in the electric field direction due to the potential switching, thereby displaying an image. Therefore, it is necessary to design the image display panel so that the particle group or the powder fluid can move uniformly and maintain the stability at the time of repetition or storage. Here, the force applied to the particles or the powder fluid may be an electric image force with the electrode or substrate, an intermolecular force, a liquid crosslinking force, gravity, etc., in addition to the force attracted by the Coulomb force between the particles or the powder fluid. It is done.

  Next, an image display operation in the basic configuration of the above-described image display panel will be described. The image display panel used in the present invention is, for example, by moving particles 3 of two different colors (see FIG. 1; here, white particles 3W and black particles 3B) are moved in a direction perpendicular to the substrates 1 and 2. The present invention can be applied to both a panel used for a display method and a panel using a display method by moving particles 3W of one kind of color (see FIG. 2) in a direction parallel to the substrates 1 and 2. An example of a panel structure for display is shown in FIG. 1 to 3, reference numeral 4 denotes partition walls provided for forming cells, and reference numerals 5 and 6 denote electrodes for applying an electric field to the particles 3. The above description can be similarly applied to the case where the white particles 3W are replaced with the white powder fluid and the black particles 3B are replaced with the black powder fluid.

Hereinafter, the structure of the image display panel, which is a feature of the present invention, will be described.
FIGS. 4A to 4C are diagrams for explaining the configuration of an example of the image display panel of the present invention. 4A shows a transparent front substrate 2, FIG. 4B shows a rear substrate 1 having a partition wall 4, and FIG. 4C shows a case where the front substrate 2 and the rear substrate 1 are overlapped. Sectional drawing along the AA line of each is shown.

  In this example, as shown in FIG. 4A, seven front electrodes 6-1 to 6-7 for performing segment display and external signals are input to the surface of the front substrate 2 facing the rear substrate 1. The electrical signal input unit 12 having a plurality of connection units 11 provided at the end of the substrate, the front electrodes 6-1 to 6-7, and the connection units 11 of the electrical signal input unit 12 are electrically connected. Conductive wire portions 13-1 to 13-7 to be connected are provided. Further, as shown in FIG. 4B, on the surface of the rear substrate 1 facing the front substrate 2, first, as with the front substrate 2, seven rear electrodes 5-1 to 5-7 for performing segment display are provided. An electric signal input unit 15 in which a plurality of connection units 14 are provided at the end of the substrate for inputting external signals, and each of the back electrodes 5-1 to 5-7 and each of the electric signal input units 15 are connected. Conductor portions 16-1 to 16-7 that electrically connect the portion 14 are provided. Further, a grid-like partition wall 4 is provided on the upper surface. Therefore, in the example shown in FIG. 4B, the conducting wire portions 16-1 to 16-7 are hidden by the partition wall 4 and cannot be seen.

  The feature of the present invention is that the conductor portions 13-1 to 13-7 shown in FIG. 4A are configured to overlap the conductor portions 16-1 to 16-7 shown in FIG. When the image display panel is configured by superimposing the front substrate 2 and the rear substrate 1, the conducting wire portions 13-1 to 13-7 and the conducting wire portions 16-1 to 16-7 It is the point arranged between. That is, as shown in FIG. 4C, the conducting wire portions 13-1 to 13-7 are provided between the partition wall 4 and the front substrate 2, and the conducting wire portions 16-1 to 16-7 are provided between the partition wall 4 and the rear substrate. 1 and the particle groups or powdered fluids 3W and 3B are not placed on the conductor portions 13-1 to 13-7 and 16-1 to 16-7.

  In this example, in a portion other than the portion where the segment display is performed, the partition wall 21 is different from the partition wall 4 defining the display cell (here, it is disposed obliquely with respect to the partition wall 4 defining the display cell. ) Are formed in advance, and conducting wire portions 13-1 to 13-7 and 16-1 to 16-7 are arranged between the partition wall 21 and the substrates 1 and 2, respectively. Moreover, in the example mentioned above, although the pattern of the conducting wire portions 13-1 to 13-7 on the front substrate 2 and the pattern of the conducting wire portions 16-1 to 16-7 on the back substrate 1 are shown, As long as the conductive wire portions 13-1 to 13-7 and 16-1 to 16-7 are hidden by the partition wall 4, it is not always necessary to match the patterns.

  According to the image display panel of the present invention described above, the particle group or the powder fluid 3W is formed on the conductor portion by superimposing the conductor portions 13-1 to 13-7 and 16-1 to 16-7 on the partition wall 4 (21). 3B can be configured so that the conductor portion is not visible during segment display, and black on a white background and white on a black character can be displayed.

  Hereafter, each member which comprises the image display panel of this invention is demonstrated.

  As for the substrate, at least one substrate is the transparent front substrate 2 from which the color of particles or powder fluid can be confirmed from the outside of the apparatus, and a material having high visible light transmittance and good heat resistance is suitable. The back substrate 1 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and flexible materials such as glass and quartz. There are no inorganic sheets. The thickness of the substrate is preferably 2 to 400 μm, more preferably 5 to 300 μm. If it is too thin, it will be difficult to maintain the strength and the uniform spacing between the substrates, and if it is thicker than 400 μm, the stress due to bending will become strong. There is inconvenience in connection.

  For the electrodes 5 and 6, the front electrode 6 provided on the side of the front substrate 2 that needs to be visible and transparent is formed of a conductive material that is transparent and can be patterned. For example, indium oxide, aluminum, Examples thereof include metals such as gold, silver and copper, and conductive polymers such as polyaniline, polypyrrole and polythiophene, and examples thereof include vacuum deposition and coating methods. 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, thickness, and the like of the back electrode 5 provided on the back substrate 1 side are the same as those of the front electrode 6 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 wall 4 is optimally set according to the type of particle group or powder fluid involved in the display, and is not limited in general. However, the partition wall width is 2 to 100 μm, preferably 3 to 50 μm. Is adjusted to 10 to 5000 μm, preferably 10 to 500 μm. In forming the partition walls, a both-rib method in which ribs are formed on each of the opposing substrates and then bonded, and a one-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. 5, the display 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 substrate plane direction. The shape is illustrated. It is better to make the portion corresponding to the cross section of the partition wall visible from the display side (the area of the frame portion of the display cell) as small as possible, and the sharpness of the image display increases. Here, examples of the method for forming the partition include a screen printing method, a sand blasting method, a photolithography method, and an additive method. Of these, the photolithography method using a resist film is preferably used.

  Next, the particles used in the image display panel of the present invention will be described. 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 brie 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 yellow lead, 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.

  The particles used in the present invention preferably have an average particle diameter d (0.5) in the range of 0.1 to 50 μm and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the particles.

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 expressed in μm that the particle size is 50% larger than this and 50% smaller than this, and d (0.1) is a particle whose ratio is 10% or less. (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 particle 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, particles are introduced into a nitrogen stream, and 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 particles naturally depends on the measurement conditions, but the charge amount of the particles in the image display panel almost depends on the initial charge amount, the contact with the partition wall, the contact with the substrate, the charge decay with the elapsed time, In particular, it was found that the saturation value of the charging behavior of the two types of particles is the dominant factor.

  As a result of intensive studies, the present inventors have found that by using the same carrier particles in the blow-off method and measuring the charge amount of each particle, it is possible to evaluate the range of appropriate charging characteristic values of the two types of particles. It was.

  Although the measurement method will be described in detail later, the charge amount per unit weight of the particles can be measured by sufficiently bringing the particles and carrier particles into contact with each other by the blow-off method and measuring the saturated charge amount. Then, by separately obtaining the average particle diameter and specific gravity of the particles, the total number of particles and the charge amount per particle can be calculated.

Next, the powder fluid used in the image display panel of the present invention will be described.
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, a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is used as a dispersoid in the image display device of the present invention. Is.

The image 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 in a gas between opposed substrates, at least one of which is transparent. Such powder fluid can be easily and stably moved by a Coulomb force or the like by applying a low voltage.
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 image display device of the present invention, a solid substance is used in a state of relatively stably floating as a dispersoid in the gas.

The range of the aerosol state is preferably such that the apparent volume of the pulverized fluid when it is floated is twice or more that when it is not suspended, more preferably 2.5 times or more, and particularly preferably 3 times or more. Although an upper limit is not specifically limited, It is preferable that it is 12 times or less.
If the apparent volume of the pulverized fluid is less than twice that of the unfloating state, it is difficult to control the display, and if it is more than 12 times, the powder fluid will be overloaded when sealed in the device. Inconvenience in handling occurs. The apparent volume at the maximum floating time is measured as follows. That is, the powdered fluid is put into a closed container that allows the powdered fluid to permeate, and the container itself is vibrated or dropped to create a maximum floating state, and the apparent volume at that time is measured from the outside of the container. Specifically, in a container with a lid (trade name: iBoy: manufactured by ASONE Co., Ltd.) having a diameter (inner diameter) of 6 cm and a height of 10 cm, a powder fluid equivalent to 1/5 of the volume as a powder fluid when not floating. And set the container on a shaker, and shake at a distance of 6 cm at 3 reciprocations / sec for 3 hours. The apparent volume immediately after stopping shaking is the apparent volume at the maximum floating time.

Moreover, in this invention, what the time change of the apparent volume of a powder fluid satisfy | fills following Formula is preferable.
V ₁₀ / V ₅ > 0.8
Here, V ₅ represents an apparent volume (cm ³ ) 5 minutes after the maximum floating time, and V ₁₀ represents an apparent volume (cm ³ ) 10 minutes after the maximum floating time. In the image display device of the present invention, the apparent volumetric change V ₁₀ / V ₅ of the powder fluid is preferably larger than 0.85, and more preferably larger than 0.9. When V ₁₀ / V ₅ is 0.8 or less, it becomes the same as when ordinary so-called particles are used, and it becomes impossible to ensure the effect of high-speed response and durability as in the present invention.

  Moreover, the average particle diameter (d (0.5)) of the particulate material constituting the powder fluid is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and particularly preferably 0.9 to 8 μm. . If it is smaller than 0.1 μm, it is difficult to control the display, and if it is larger than 20 μm, the display is not clear. The average particle diameter (d (0.5)) of the particulate material constituting the powder fluid is the same as d (0.5) in the next particle diameter distribution Span.

The particle substance constituting the powder fluid preferably has a particle size distribution Span represented by the following formula of less than 5, more preferably less than 3.
Particle size distribution Span = (d (0.9) -d (0.1)) / d (0.5)
Here, d (0.5) is a numerical value expressed in μm of the particle diameter that 50% of the particulate material constituting the powder fluid is larger than this and 50% is smaller than this, and d (0.1) is less than this. A numerical value in which the ratio of the particle substance constituting the powder fluid is 10%, expressed in μm, and d (0.9) is the particle diameter in which the particulate substance constituting the powder fluid is 90% μm It is a numerical value expressed by By setting the particle size distribution Span of the particulate material constituting the powder fluid to 5 or less, the sizes are uniform and uniform powder fluid movement becomes possible.

  The above particle size distribution and particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated to the powder fluid to be measured, a light intensity distribution pattern of diffracted / scattered light is generated spatially, and this light intensity pattern has a corresponding relationship with the particle diameter, so the particle diameter and particle diameter distribution are measured. it can. This particle size and particle size distribution are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring machine, the powdered fluid was introduced into the nitrogen stream, and the attached analysis software (software based on volume reference distribution using Mie theory) Measurements can be made.

  Preparation of powder fluid can be done by kneading and pulverizing the necessary resin, charge control agent, colorant, and other additives, or by polymerization from monomers, and adding existing particles to resin, charge control agent, colorant, and other It may be coated with an agent. Hereinafter, the resin, charge control agent, colorant, and other additives constituting the powder fluid will be exemplified.

  Examples of the resin include urethane resin, acrylic resin, polyester resin, urethane-modified acrylic resin, silicone resin, nylon resin, epoxy resin, styrene resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluorine resin, etc. Two or more types can also be mixed. In particular, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, urethane resin, and fluororesin are preferable from the viewpoint of controlling the adhesive force with the substrate.

  Examples of charge control agents include quaternary ammonium salt compounds, nigrosine dyes, triphenylmethane compounds, imidazole derivatives and the like in the case of imparting positive charges, and metal-containing azo compounds in the case of imparting negative charges. Examples thereof include dyes, salicylic acid metal complexes, and nitroimidazole derivatives.

  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 brie 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 yellow lead, 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.

Furthermore, in the present invention, it is important to manage the gas in the voids surrounding the particle group or the powder fluid between the substrates, which contributes to the improvement of display stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, more preferably 35% RH or less with respect to the humidity of the gas in the gap.
1 to 3, the gaps between the opposing substrate 1 and substrate 2 in FIGS. 1 to 3, the occupied portions of the electrodes 5 and 6, the particle group (or powder fluid) 3, the occupied portion of the partition 4, and the device A gas portion that is in contact with a so-called particle group (or powder fluid) excluding the seal portion 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 the apparatus so that the humidity is maintained. For example, filling of particles or powder fluid, assembly of the substrate, etc. are performed in a predetermined humidity environment, It is important to apply a sealing material and a sealing method to prevent moisture intrusion.

The distance between the substrate in the image display panel of the present invention is not limited as long as the particle group or powder fluid can move and maintain the contrast, but is usually adjusted to 10 to 5000 μm, preferably 10 to 500 μm.
The volume occupancy of the particle group or powder fluid in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. If it exceeds 70%, the movement of the particles or powder fluid is hindered, and if it is less than 5%, the contrast tends to be unclear.

  The image display panel according to the present invention includes display units for 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, calculators, and home appliances. It is suitably used for display parts for automobile supplies, card display parts such as point cards and IC cards, electronic advertisements, electronic POPs, electronic price tags, electronic musical scores, and display parts for RF-ID devices.

It is a figure which shows an example of the drive method in the image display panel of this invention. It is a figure which shows the other example of the drive method in the image display panel of this invention. It is a figure which shows an example of the structure of the image display panel of this invention. (A)-(c) is a figure for demonstrating the structure of an example of the image display panel of this invention, respectively. It is a figure which shows an example of the shape of the partition in the image display panel of this invention.

Explanation of symbols

1 Back substrate (second substrate)
2 Front substrate (first substrate)
3 particles (powder fluid)
3W white particles (white powder fluid)
3B Black particles (black powder fluid)
4 Bulkhead 5, 5-1 to 5-7 Rear electrode 6, 6-1 to 6-7 Front electrode 11, 14 Connection unit 12, 15 Electric signal input unit 13-1 to 13-7, 16-1 to 16- 7 Conductor part

Claims (2)

  At least one of the transparent substrates is a transparent substrate, and a first substrate having an electrode portion formed on the surface and a second substrate having an electrode portion formed on the surface and a partition defining a display cell are mutually connected. In the image display panel in which the electrode portions are stacked so as to face each other and the particle group or the powder fluid is sealed therebetween, and at least one of the electrode portions is arranged in a segment shape to perform segment display. An image display panel characterized in that, in each of the substrate and the second substrate, a conductor portion for electrically connecting the electrode portion and the electric signal input portion is disposed between each substrate and the partition wall.   2. A partition other than a partition defining a display cell is formed in advance in a portion other than a segment display portion, and a conductor portion is disposed between the partition and each substrate. The image display panel described in 1.

Images