JP4902956B2 - Information display panel and information display device - Google Patents

Description

  The present invention encloses a display medium by enclosing at least one display medium having optical reflectivity and chargeability between two opposing substrates, at least one of which is transparent, and applying an electric field to the display medium. The present invention relates to an information display panel and an information display device for displaying information such as an image by moving an image.

  2. Description of the Related Art Conventionally, information display devices using techniques such as electrophoresis, electrochromic, thermal, and two-color particle rotation have been proposed as information display devices that 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 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 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. 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 uniformly inject the charge into the conductive particles.

As one method for solving the various problems described above, at least two or more types of display media having optical reflectivity and chargeability are sealed between two opposing substrates, at least one of which is transparent, and then displayed. 2. Description of the Related Art An information display panel and an information display device that display an information such as an image by applying an electric field to a medium and moving the display medium are 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

  In the case of these information display panels of the display medium moving display system, the display medium is sealed between the substrates. In order to prevent the display medium from becoming unevenly distributed as the display medium is repeatedly moved, a partition wall is used. A method of enclosing a display medium in an enclosed small room (cell) is used. In addition, in these displays, it is necessary to generate an electric field in the substrate in order to drive the display medium, but the line has been developed so that a passive drive system capable of achieving both clear display and efficient productivity can be performed. A matrix electrode pair is formed on the two substrates so that the line electrodes intersect each other. At this time, a transparent and conductive polymer material such as ITO (indium tin oxide) has been used because the line electrode material provided on the display surface side substrate needs to be transparent.

  However, these electrode materials have higher electrical resistance than metal materials, and if the wiring distance to the pixel part at the end of the wiring is long, the electrode material becomes a high resistance body, and is flexible compared to metal materials. Therefore, disconnection and broken lines are easy to occur, and there is a problem in terms of energization reliability.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an information display panel and an information display device that eliminates the above-mentioned problems and is excellent in all of the reduction in resistance of the entire electrode and electrode wiring, the electrification reliability of the electrode, and the visibility. It is something to be offered.

The information display panel of the present invention encloses at least two kinds of display media having optical reflectivity and chargeability between two opposing substrates, at least one of which is transparent, both of the two substrates. An information display panel that displays an information such as an image by applying an electric field to a display medium by applying a potential difference between a pair of electrodes provided opposite to each other and moving the display medium, and at least a display surface side substrate in the longitudinal direction of the left or right either edge of the transparent line electrodes provided on, as well as features an electrode wiring formed of a metal wire in contact with the transparent line electrodes, features have been electrode wiring line electrodes of the display surface side substrate Is used as an electrode for connection with another device at each longitudinal end .

As a preferred example of the information display panel of the present invention, a colored pattern having an OD value of 2 or more is formed on the electrode wiring provided alongside the line electrode of the display surface side substrate. The electrode wiring provided alongside the line electrode is provided on a colored pattern having an OD value of 2 or more formed on the display surface side substrate, and a plurality of partitions separated by a partition between the two substrates In the case of forming a cell, there are cases where an electrode wiring provided alongside the line electrode of the display surface side substrate is provided under the partition, and the display medium is a particle group or a powder fluid.

  The information display device of the present invention is characterized by mounting the information display panel having the above-described configuration.

  According to the present invention, at least one of the left and right edges in the longitudinal direction of the transparent line electrode provided on the display surface side substrate is provided with an electrode wiring having a low resistance and excellent flexibility in contact with the transparent line electrode. Thus, it is possible to obtain an information display panel and an information display device that are excellent in all of the reduction in resistance of the electrode and the entire electrode wiring, the energization reliability of the electrode, and the visibility.

  First, the basic configuration of the information display panel of the present invention will be described. In the information display panel of the present invention, an electric field is applied to a display medium sealed between two opposing substrates. A display medium charged at a low potential toward the high potential side along the direction of the applied electric field is attracted by the electric field force or Coulomb force, and the display medium is charged at a high potential toward the low potential side. The medium is attracted by an electric field force, a Coulomb force, or the like, and the display medium reciprocates due to a change in the electric field direction due to a potential change, thereby displaying information such as an image. Therefore, it is necessary to design the information display panel so that the display medium moves uniformly and can maintain stability when repeatedly displaying or storing display information. Here, as the force applied to the particles constituting the display medium, in addition to the force attracted by the Coulomb force between the particles, an electric image force with the electrode and the substrate, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

  An example of the information display panel of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). In the example shown in FIGS. 1A and 1B, at least two types of display media 3 (here, white display consisting of a group of particles) having at least one type of particles and different optical reflectance and charging characteristics. The substrate 1 corresponds to an electric field generated by applying a voltage between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2. 2, the black display medium 3 </ b> B is visually recognized by the observer and black display is performed, or the white display medium 3 </ b> W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1B, in addition to the example shown in FIG. 1A, for example, a grid-like partition wall 4 is provided between the substrates 1 and 2 to form a display cell. Further, in the example shown in FIGS. 1A and 1B, the front partition 4 is 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. I can do it.

  2 (a) to 2 (c) are views showing the structure of an example of the information display panel of the present invention, FIG. 2 (a) shows a bottom view thereof, and FIG. 2 (b) shows a front view thereof. FIG. 2 (c) shows a side view thereof. The example shown to Fig.2 (a)-(c) has shown the state of the board | substrate 2 by the side of a display surface. In this example, a plurality of transparent line electrodes 6 are formed on a transparent substrate 2, a colored pattern 11 having an OD value of 2 or more (usually black) is provided on the line electrode 6, and a partition wall 4 is provided thereon. Yes. A feature of the present invention is that an electrode wiring 12 having low resistance and excellent flexibility is provided in contact with the transparent line electrode 6 at the edge in the longitudinal direction of the transparent line electrode 6 provided on the transparent substrate 2 on the display surface side. It is in the point where it was added.

  FIG. 3 is a diagram showing a state in which the display surface side substrate 2 and the back surface side substrate 1 shown in FIGS. 2A to 2C are overlapped so that the line electrodes and the partition walls are orthogonal to each other. In the example shown in FIG. 3, the configuration is the same as that of a normal information display panel except that a predetermined electrode wiring 12 is provided at the edge of the line electrode 6. In addition, although the electrode wiring 12 can be provided also in the edge part of the line electrode 5 of the board | substrate 1 of the back side, it is not an essential structure. Further, the partition wall 4 may not be provided. Furthermore, the electrode wiring 12 can be provided on both edges of the line electrode 6 on the substrate 2 on the display surface side. Furthermore, when providing the partition 4, it is preferable to comprise so that the electrode wiring 12 may be arrange | positioned in the position corresponding to the partition 4 (colored pattern 11).

  FIG. 4 is a diagram for explaining an example of white display in the information display panel shown in FIG. As shown in FIG. 4, the white display medium 3W is moved to the substrate 2 on the display surface side, the black display medium 3B is moved to the substrate 1 on the back side, and the white display medium 3W is moved to the transparent substrate 2 on the display surface side. Observation is performed through the transparent line electrode 6. At this time, if the colored pattern 11 is present, as shown in FIG. 5A, the electrode wiring 12 is integrated with the colored pattern 11 and is not conspicuous through the transparent substrate 2 and the transparent line electrode 6. If the colored pattern 11 does not exist, the electrode wiring 12 and the partition wall 4 are directly viewed through the transparent electrode 6 and the transparent substrate 2 as shown in FIG. The

  As described above, in the information display panel of the present invention, the line electrode 6 is made of a transparent electrode material such as ITO, and at least one of the left and right edges of the line electrode 6 is not transparent such as a metal material. A configuration is adopted in which a material having sufficient flexibility, low resistance, and high conductivity is disposed as the electrode wiring 12 in contact. The electrode wiring 12 provided at the edge of the line electrode 6 may be any material that has a low resistivity, is flexible, and has a high reliability of conduction. Metal materials such as gold, silver, copper, and aluminum are preferably used. It is done.

  The electrode wiring 12 provided on the edge of the line electrode 6 on the substrate 2 on the display surface side is on the colored pattern 11 having an OD value of 2 or more provided on the bonding surface between the partition wall 4 forming the cell and the substrate 2 or the colored pattern 11. Provide below. Thereby, even the non-transparent electrode wiring 12 can be made invisible to the observer. In addition, the line electrode 5 provided on the substrate 1 on the back side is not transparent to the observer even if it is non-transparent, and therefore, a flexible material with high reliability of conduction is used alone as an electrode material and an electrode wiring. What is necessary is just to use as a material. When the flexibility of the electrode material is insufficient and the conduction reliability is also insufficient, the resistivity of the present invention is small, and the material having flexibility and high conduction reliability is applied to the electrode as an electrode wiring. What is necessary is just to take the structure arrange | positioned in a contact state.

  Even if the line electrodes 5 and 6 have insufficient flexibility and current-carrying reliability, a material having a low resistivity, sufficient flexibility and high current-carrying reliability is used as the electrode wiring 12 at the edge thereof. By adopting a configuration arranged in a contact state, even if the line electrodes 5 and 6 are disconnected, the electrode wiring 12 of the present invention provided at the edge portion does not disconnect, so that it can function as a compensating conductor. . Although the resistance of transparent conductive polymer materials such as ITO is not sufficiently low, the resistance of the edges of the line electrodes 5 and 6 made of the above-described materials is small and flexible. The resistance of the line electrodes 5 and 6 as a whole can be reduced by adopting a configuration in which a metal material or the like having high energization reliability is arranged in contact with the electrode wiring 12.

  Hereinafter, the information display panel according to the present invention will be described in more detail with reference to FIGS. 6 (a) and 6 (b) are diagrams for explaining other examples of the information display panel, FIG. 6 (a) shows a front view thereof, and FIG. 6 (b) shows FIG. ) Shows a cross-sectional view along the line AA in FIG. In the example shown in FIGS. 6A and 6B, the electrode wiring 12 is arranged on the left side in FIG. 6A of the line electrode 6 of the substrate 2 on the display surface side. In this example, after the colored pattern 11 is formed, the electrode wiring 12 is formed. FIGS. 7A and 7B are diagrams for explaining still another example of the information display panel. FIG. 7A shows a front view thereof, and FIG. Sectional drawing along the AA in a) is shown. In the example shown in FIGS. 7A and 7B, the electrode wiring 12 is arranged on the left side in FIG. 7A of the line electrode 6 of the substrate 2 on the display surface side. In this example, the colored pattern 11 is formed after the electrode wiring 12 is formed.

  FIGS. 8A and 8B are diagrams for explaining an example of the line electrode in the information display panel of the present invention. As shown in FIG. 8 (a), the plurality of line electrodes 6 (5) arranged in parallel are provided with the electrode wiring 12 at the edge in the longitudinal direction, and the electrode wiring 12 is provided at each longitudinal end. Is directly used as an electrode for connection with other devices. Then, as shown in FIG. 8B, the display pixel is configured by overlapping the line electrode 6 on the display surface side and the line electrode 5 on the back surface so as to be orthogonal to each other.

  In the information display panel of the present invention described above, as shown in FIG. 9A, the transparent substrate 2 / transparent line electrode 6 (with electrode wiring 12 provided) / colored pattern 11 from the display surface side. In the case of the example in which the colored patterns are arranged in order, FIG. 9B shows an example in which the colored patterns are arranged in a grid pattern, and FIG. 9C shows an example in which the colored patterns are arranged in a stripe pattern. In addition, the colored pattern 11 is visually recognized through the transparent line electrode 6 or the electrode wiring 12 is visually recognized through the transparent substrate 2. Further, as shown in FIG. 10A, in the case of an example in which the transparent substrate 2 / colored pattern 11 / transparent line electrode 6 (electrode wiring 12 is provided) are arranged in this order from the display surface side. The colored pattern 11 is visually recognized through the transparent substrate 2 as shown in an example in which a colored pattern is arranged in a grid pattern in 10 (b) and in an example in which a colored pattern is arranged in a stripe pattern in 10 (c). It becomes.

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

  For the partition 4 of the present invention, it is important to provide a colored portion having an OD value of 2 or more between at least the partition lower portion provided on the display surface side substrate and the display surface side substrate. The width of the partition wall is adjusted to 2 to 100 μm, preferably 3 to 50 μm, and the height of the partition wall is adjusted to 10 to 500 μm, preferably 10 to 200 μm. Is done. The cell shape of the information display panel obtained by superimposing the display surface side substrate and the back side substrate may be various shapes as illustrated in FIG. A colored portion having an OD value of 2 or more provided between the lower part of the partition wall and the display surface side substrate may correspond to the wiring provided along with the transparent line electrode, and the shape of the partition wall is not limited at all. It is better to make the portion corresponding to the partition cross section visible from the display surface side (the area of the frame portion of the display cell formed by the width of the partition) as small as possible, and the sharpness of the displayed information image increases.

  As for the substrate, at least one substrate (display surface side substrate) is a transparent substrate 2 from which the color of the display medium can be confirmed from the outside of the information display panel, and a material having high visible light transmittance and good heat resistance is preferable. It is. The 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 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.

  Regarding the electrodes arranged on both the substrate sides, the display surface side electrode 6 provided on the display surface side substrate 2 that needs to be transparent on the display surface side is formed of a conductive material that is transparent and can be patterned, Examples 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; and conductive polymers such as polyaniline, polypyrrole, and polythiophene. Those having transparency are appropriately selected and used. As a method for forming an electrode, a method of forming the above-described materials into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or mixing a conductive agent with a solvent or a synthetic resin binder. The method of apply | coating is 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 back side electrode 5 provided on the back side substrate 1 are the same as those of the display surface side electrode 6 described above. However, the back side electrode 5 does not have to be transparent, and a low resistance and high current-carrying reliability can be appropriately selected. Used. In this case, the external voltage input may be superimposed with direct current or alternating current.

  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 as the display medium 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 that exhibits high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, as a display medium, between opposing substrates, at least one of which is transparent. Such a powder fluid can be easily and stably moved by a Coulomb force or the like by applying a low voltage.
As described above, for example, the powder fluid used as the display medium in the present invention is a substance in the intermediate state between the 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, a solid substance is used in a state of relatively stably floating 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, resol 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.

As yellow colorants, yellow lead, 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, Indanthren 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.

  Further, the particles of the present invention 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 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 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 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 used for the display medium naturally depends on the measurement conditions, but the charge amount of the particles used for the display medium in the information display panel is almost the initial charge amount, the contact with the partition, the contact with the substrate, the elapsed time. It was found that the saturation value of the charging behavior of the particles used in the display medium is a governing factor, depending on the charge decay associated with.

  As a result of intensive studies, the present inventors evaluated the range of the appropriate charging characteristic value of the particles used in the display medium 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 out that I can do it.

Furthermore, when a particle group or a powder fluid is used as a display medium in a dry information display panel, it is important to manage the gas in the void 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, preferably 50% RH or less, more preferably 35% RH or less with respect to the humidity of the gas in the gap.
In FIG. 1A and FIG. 1B, the void portion refers to the portion occupied by the electrodes 5 and 6 and the display medium (particle group or powder fluid) 3 from the portion sandwiched between the opposing substrate 1 and substrate 2, partition walls 4 indicates a gas portion in contact with a so-called display medium excluding an occupied portion (when a partition wall is provided) 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, etc. 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 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.

  Hereinafter, the present invention and a comparative example will be shown to specifically describe the present invention, but the present invention is not limited to the following. In addition, the information display panel of an Example and a comparative example evaluated what produced by the following method according to the following reference | standard.

"Display media"
In Examples and Comparative Examples, black and white two-color particle groups (particle group A and particle group B) having different charging characteristics were used as display media.
Particle group A consists of acrylic urethane resin EAU53B (manufactured by Asia Industry Co., Ltd.) / IPDI crosslinking agent Excel Hardener HX (manufactured by Asia Industry Co., Ltd.) and 4 parts by weight of carbon black (MA100 Mitsubishi Chemical Corporation), charge control. 2 parts by weight of the agent Bontron N07 (Orient Chemical Co., Ltd.) was added, kneaded, pulverized with a jet mill, and mechanical impact force was applied using a hybridizer device (Nara Machinery Co., Ltd.). In addition, classification was made after making it approximately spherical. The produced particle group A was an approximately spherical and negatively charged black particle group having an average particle diameter of 9.1 μm.
Particle group B was prepared by dissolving 0.5 parts by weight of AIBN (azobisisobutyronitrile) in 80 parts by weight of tertiary butyl methacrylate monomer and 20 parts by weight of 2- (diethylamino) ethyl methacrylate. The liquid obtained by dispersing 20 parts by weight of titanium oxide made lipophilic by treatment with an agent is suspended and polymerized in an aqueous solution of 0.5% surfactant (sodium lauryl sulfate), filtered, dried. Then, it was prepared using a classifier (MDS-2: Nippon Numatic Industries). The produced particle group B is a positively charged spherical white particle having an average particle diameter of 8.5 μm.

<Example 1>
A glass transparent substrate (20 cm □) provided with an ITO line electrode (width: 300 μm, line pitch: 340 μm) with a copper electrode wiring in contact with the edge so as to overlap the copper electrode wiring. Thus, a colored pattern (square, grid-like arrangement) having an OD value 3 corresponding to the pixel size was formed. Further, a dry film photoresist NIT250 made by Nichigo Morton, which is a photosensitive film, is laminated thereon, and a partition (height: 50 μm) corresponding to the pixel size is formed by exposure and development, and the display medium is filled. What was made into the cell (square, lattice-like arrangement | positioning) to be prepared was prepared. A glass transparent substrate provided with an ITO line electrode (width: 300 μm, line pitch: 340 μm) provided with a copper electrode wiring in contact with the edge of the other substrate was also prepared.
Next, two kinds of particle groups (particle group A and particle group B) having different colors and charging characteristics are first filled with the particle group A into the cell of the display surface side substrate provided with the partition walls, and then the particles Group B was filled.
The packing arrangement amount of the particle group A and the particle group B was set to the same volume amount, and the volume occupation ratio of both particle groups with respect to the space between the substrates formed by bonding the two substrates was adjusted to 25 vol%. Next, the other substrate is overlapped with the substrate in which the particle group is filled and arranged in the cell so that the electrodes are orthogonal to each other, and the outer peripheral portion around the substrate is bonded and sealed with an epoxy-based adhesive. Was sealed to produce an information display panel.
The produced information display panel was evaluated by the method described below. The results are shown in Table 1.

<Example 2>
An ITO line electrode with a copper electrode wiring in contact with an edge on a glass transparent substrate on which a colored pattern (square, grid-like arrangement) with an OD value 3 corresponding to the pixel size is formed is just made of copper. The electrode wiring portion was provided so as to overlap the colored pattern. Further, a dry film photoresist NIT250 made by Nichigo Morton, which is a photosensitive film, is laminated thereon, and by exposure and development, a partition corresponding to the pixel size is formed to fill a display medium (square, lattice Prepared). Otherwise, an information display panel was produced in the same manner as in Example 1.
The produced information display panel was evaluated by the method described below. The results are shown in Table 1.

<Example 3>
The other glass substrate used for the glass transparent substrate provided with the ITO line electrode provided with the copper electrode wiring in contact with the edge portion, except that the copper line electrode was formed, An information display panel was produced in the same manner as in Example 1.
The produced information display panel was evaluated by the method described below. The results are shown in Table 1.

<Comparative Example 1>
An information display panel was produced in the same manner as in Example 3 except that a transparent glass substrate provided with only ITO line electrodes without an electrode wiring made of copper at the edge was used.
The produced information display panel was evaluated by the method described below. The results are shown in Table 1.

"Evaluation of information display panel"
10 pieces of information display panels described in Examples 1 to 3 and Comparative Example 1 are manufactured and incorporated in the information display device, and voltage is applied to the electrodes so as to perform white solid image display and black solid image display. Then, the quality of the displayed solid image was visually observed and evaluated.

  The information 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 shelf labels, electronic musical scores, and display parts for RF-ID devices.

(A), (b) is a figure which shows an example of the information display panel of this invention, respectively. (A)-(c) 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 state which piled up the board | substrate of the display surface side shown in FIG. 2 (a)-(c), and the board | substrate of the back side. It is a figure for demonstrating the example of the white display in the information display panel shown in FIG. (A), (b) is a figure for demonstrating the visual recognition state from the display surface side in the case where there is a colored pattern in the information display panel of this invention, respectively, and when there is no. (A), (b) is a figure for demonstrating the other example of the information display panel, respectively. (A), (b) is a figure for demonstrating the further another example of the information display panel, respectively. (A), (b) is a figure for demonstrating an example of the line electrode in the information display panel of this invention, respectively. (A)-(c) is a figure for demonstrating the visual recognition state from the display surface side at the time of forming a panel in order of a board | substrate / electrode / colored pattern in the information display panel of this invention, respectively. (A)-(c) is a figure for demonstrating the visual recognition state from the display surface side at the time of forming a panel in order of a board | substrate / colored pattern / 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.

Explanation of symbols

1, 2 Substrate 3 Display medium (particle group or powder fluid)
3W White display medium 3B Black display medium 4 Bulkhead 5, 6 Line electrode 11 Colored pattern 12 Electrode wiring

Claims (6)

An electrode pair formed by enclosing at least two kinds of display media having optical reflectivity and chargeability between two opposing substrates, at least one of which is transparent, and facing both of the two substrates. An information display panel that displays an information such as an image by applying an electric potential difference between the display medium and moving the display medium, and at least in the longitudinal direction of the transparent line electrode provided on the display surface side substrate left right either edge, with features an electrode wiring formed of a metal wire in contact with the transparent line electrodes, an electrode wiring which is parallel in the line electrodes of the display surface side substrate, each of the longitudinal ends And an information display panel characterized by being used as an electrode for connection with another device .   The information display panel according to claim 1, wherein a colored pattern having an OD value of 2 or more is formed on an electrode wiring provided alongside the line electrode of the display surface side substrate.   2. The electrode wiring provided alongside the line electrode of the display surface side substrate is provided on a colored pattern having an OD value of 2 or more formed on the display surface side substrate. The information display panel described. When forming a plurality of cells partitioned by the two partition walls between the substrates, claim 1-3, characterized in that providing an electrode wiring which is parallel in the line electrodes of the display surface side substrate under the partition wall The information display panel according to any one of the above. The information display panel according to any one of claims 1 to 4, wherein said display medium is particles or liquid powders. Information display device characterized by mounting the information display panel according to any one of claims 1-5.

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