JP2006085162A - Manufacturing method of panel for information display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a panel for information display, wherein a narrow space in a cell enclosed by partitions on a substrate can be uniformly filled with two display mediums, having charge characteristics different from each other at a prescribed rate, before substrates are stuck to each other and to provide the inexpensive panel for information display having superior image quality of display information. <P>SOLUTION: When the panel for information display is manufactured, displaying information by forming a plurality of cells partitioned by partitions 4 between the two substrates at least one of which is transparent and which face each other, encapsulating the two display mediums 3W and 3B having charge characteristics different from each other in the cells and applying an electric field to the display mediums to transfer the display mediums and to display information, after the cells have been filled with the first display medium 3B, the first display medium 3W with which the cells have been filled is electrically discharged, before the cells are filled with the second display medium 3B and then the cells are filled with the second display medium 3B, to be superimposed on the first display medium 3W. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a plurality of cells partitioned by a partition are formed between two opposing substrates, at least one of which is transparent, and two types of display media having different charging characteristics are sealed in the cells. The present invention relates to a method for manufacturing an information display panel that displays information such as an image by moving a display medium by applying an electric field.

  2. Description of the Related Art Conventionally, information display devices that use technologies such as electrophoresis, toner (particle) transfer, electrochromic, thermal, and two-color particle rotation have been proposed as information displays that replace liquid crystal (LCD). Yes.

  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. In particular, recently, an electrophoretic method (for example, see Non-Patent Document 1) in which a dispersion liquid composed of dispersion particles and a colored solution is microencapsulated and disposed between opposing substrates has been proposed and expected. It has been.

  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, it is difficult to maintain the stability of the dispersed state, and the stability when rewriting display information repeatedly is lacking. I have a problem. 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, this method has a complicated structure due to the arrangement of the charge transport layer and further the charge generation layer, and it is difficult to inject constant charges into the conductive particles. There is also a problem of lacking.

  As one method for solving the various problems described above, a plurality of cells partitioned by a partition are formed between two opposing substrates at least one of which is transparent, and two types having different charging characteristics are formed in the cells. There is known an information display device including an information display panel that displays information such as an image by moving the display medium by enclosing the display medium and applying an electric field to the display medium.

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”, p.249-252

  In the information display panel as described above, when a display medium is sealed in a small room (cell) surrounded by a partition wall, the display medium is filled in the cell before overlapping the substrates. When filling the display medium in the narrow space in the cell with two types of display media having different charging characteristics dispersed and filled in the cell, the first display medium filled first The charge polarity of the second display medium is different from the charge polarity of the second display medium that is subsequently filled. Therefore, when the second display medium is dispersed, the first display medium and the second display medium are aggregated. Since two types of display media having different charging characteristics cannot be uniformly filled in the cells at a predetermined ratio, a problem arises in the image quality of display information.

  The present invention provides an information display panel capable of uniformly filling two kinds of display media having different charging characteristics into a narrow space in a cell surrounded by a partition on a substrate at a predetermined ratio before the substrates are overlaid. It is an object of the present invention to provide a method and provide an inexpensive information display panel excellent in image quality of display information.

  In order to achieve the above object, a method for manufacturing an information display panel according to the present invention includes forming a plurality of cells partitioned by a partition between two opposing substrates, at least one of which is transparent, and charging the cells. A method for manufacturing an information display panel that encloses two types of display media having different characteristics and applies an electric field to the display medium to display information such as images by moving the display medium. After filling the medium in the cell and before filling the second display medium, the first display medium filled in the cell is neutralized, and then the second display medium is overlaid on the first display medium. It is characterized by filling.

As a preferred example of the method for manufacturing the information display panel of the present invention, as a method of filling the first display medium and the second display medium, the first display medium and the second display medium are arranged from a nozzle disposed on a substrate. The display medium is sprayed separately into the air and filled in the cells on the substrate by free fall, and the second display medium is overlaid on the first display medium, and the first display medium is filled. When the display medium is neutralized and then the second display medium is overlaid and filled on the first display medium, a voltage having a sign opposite to that of the charging characteristic of the second display medium is applied to the substrate. The display medium may be overlaid on the first display medium, and the display medium may be a particle group or a powder fluid.
When two types of display media having different charging characteristics are applied by applying a voltage to the substrate, the charging characteristics of the first display medium are charged when the second display medium is filled after the first display medium is filled. Therefore, the first display medium is repelled, and the filling state in the cell becomes sparse or scattered. By neutralizing the first display medium, it is possible to apply a voltage having the opposite sign to the charging characteristic of the second display medium (the same sign as the charging characteristic of the first display medium). The second display medium can be satisfactorily filled without impairing the filling state of the medium.

  According to the method for manufacturing an information display panel of the present invention, a plurality of cells partitioned by partition walls are formed between two opposing substrates, at least one of which is transparent, and the charging characteristics differ in the cells. When manufacturing an information display panel that displays information such as an image by moving a display medium by enclosing a type of display medium and applying an electric field to the display medium, the first display medium is placed in the cell. After charging, before charging the second display medium, the first display medium filled in the cell is neutralized, and the second display medium is overlaid and filled on the first display medium. Since the charge characteristic of the first display medium filled first is eliminated and eliminated, the particles constituting the first display medium can be used even if the second display medium filled thereafter has the charge characteristic. The particles constituting the second display medium aggregate with each other. There is prevented, can be uniformly sprayed fill two types of display media having different charge characteristics in the cell at a predetermined ratio. Therefore, it is possible to provide an inexpensive information display panel that is excellent in image quality of display information.

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

  First, the configuration of the information display panel of the information display device of the present invention will be described. In the information display device of the present invention, an electric field is applied by some means in the substrate of the information display panel in which the display medium is sealed between the opposing substrates. The display medium charged according to the electric field direction is attracted by the force of the electric field or the Coulomb force, and the display medium changes the moving direction by switching the electric field direction, whereby information such as an image is displayed. Therefore, it is necessary to design an information display panel so that the display medium can move uniformly and maintain stability when the display information is repeatedly rewritten or when the display information is continuously displayed. There is. 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, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

An example of an information display panel used in the information display device of the present invention will be described with reference to FIGS.
In the example shown in FIG. 1, at least two or more types of display media 3 (here, white particle group 3W composed of particles 3Wa for white display media) having different optical reflectance and charging characteristics composed of at least one type of particles. The black particle group 3B including the black display medium particles 3Ba is moved in a direction perpendicular to the substrates 1 and 2 according to the electric field applied from the outside of the substrates 1 and 2, and the black particle group 3B is visually recognized by an observer. The black display is performed, or the white particle group 3W is visually recognized by the observer to perform the white display. In the example shown in FIG. 1, for example, a partition 4 is provided in a lattice shape between the substrates 1 and 2 to form a cell.
In the example shown in FIG. 2, at least two or more types of display media 3 (here, white particle group 3W composed of particles 3Wa for white display media) having different optical reflectance and charging characteristics composed of at least one type of particles. In accordance with the 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, the black particle group 3 </ b> B composed of the black display medium particles 3 </ b> Ba is shown. The black particle group 3 </ b> B is visually recognized by the observer to perform black display, or the white particle group 3 </ b> W is visually recognized by the observer to perform white display. In the example shown in FIG. 2, for example, a partition 4 is provided in a lattice shape between the substrates 1 and 2 to form a cell.
The above description can be similarly applied to the case where the white particle group 3W is replaced with a white powder fluid and the black particle group 3B is replaced with a black powder fluid.

Hereinafter, a method for manufacturing an information display panel, which is a feature of the present invention, will be described in detail based on FIGS. 3 (a) to 3 (e) and FIGS. 4 (a) to 4 (d).
When manufacturing the information display panel of the present invention, first, as shown in FIG. 3A, above one substrate (for example, a transparent substrate on the observer side) 1 on which the partition wall 4 is formed. Then, for example, a positively charged white display medium 3W is sprayed as a first display medium by the spray nozzle 11 and allowed to fall freely, and the inside of the cell formed on the substrate by the partition walls 4 as shown in FIG. Is filled with white display medium 3W. Next, as shown in FIG. 3C, the neutralization device 12 disposed above the substrate 1 neutralizes the white display medium 3W filled in the cell. As a result, the charging characteristic of the white display medium 3W, which has been positive (+) as shown in FIG. 4A, is eliminated and eliminated as shown in FIG. 4B. Next, as shown in FIG. 3D, a negatively charged black display medium 3B is sprayed as a second display medium by the spray nozzle 11 from above the substrate 1 after the filling of the white display medium 3W. When the black display medium 3B is completely sprayed, the black display medium 3B is overlaid and filled in the cells formed on the substrate by the partition walls 4, as shown in FIG. At this time, since the white display medium 3W filled in the cell has been neutralized, as shown in FIG. 4B, it is charged negatively (−) on the uncharged white display medium 3W. The white display medium 3W and the black display medium 3B are not aggregated in a state where the black display medium 3B is on.

  3A to 3E, the black display medium 3B is sprayed after the white display medium 3W is sprayed. However, the white display medium 3W is sprayed after the black display medium 3B is sprayed. In this case, as shown in FIG. 4 (c), the black display medium 3B filled in the negatively charged cells is discharged, and FIG. After the charging characteristics of the black display medium 3B are lost as shown in d), the black display medium 3B is positively (+) charged on the uncharged black display medium 3B as shown in FIG. The white display medium 3 </ b> W may be overlaid and sprayed.

  According to the present invention, a plurality of cells partitioned by partition walls are formed between two opposing substrates at least one of which is transparent, and two types of display media 3W and 3B having different charging characteristics are enclosed in the cells. When manufacturing an information display panel that displays information such as images by moving the display media 3W and 3B by applying an electric field to the display media 3W and 3B, the first display medium is placed in the cell. After charging, before charging the second display medium, the first display medium filled in the cell is neutralized by the static eliminator 12, and then the second display medium is overlaid on the first display medium. Since the charge polarity of the first display medium that has been filled is eliminated after the charge is eliminated, the first display medium can be used even if the second display medium that is filled thereafter has charging characteristics. Particles constituting the particles and particles constituting the second display medium; It will be prevented from aggregating with each other. Furthermore, as shown in FIG. 6, when the first display medium filled in the cell is neutralized and a voltage having an opposite sign to the charging characteristic of the second display medium is applied to the substrate, the second display medium is applied to the substrate. It becomes easy to be attracted and is preferable. Therefore, two types of display media having different charging characteristics can be uniformly dispersed and filled in the cell at a predetermined ratio, and an inexpensive information display panel excellent in image quality of display information can be provided.

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

  As for the substrate, at least one of the substrates is a transparent substrate on which the color of the display medium can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The back substrate as the other substrate 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.

  Electrode forming materials for the electrodes 5 and 6 provided as necessary include metals such as aluminum, silver, nickel, copper, and gold, and transparent conductive metal oxides such as ITO, indium oxide, conductive tin oxide, and conductive zinc oxide. Examples thereof include conductive polymers such as substances, polyaniline, polypyrrole and polythiophene, which 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 electrode 5 provided on the back substrate side are the same as those of the 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 4 is optimally set according to the type of display medium involved in the display and is not limited in general. However, the width of the partition is 2 to 100 μm, preferably 3 to 50 μm, and the height of the partition is 10 to 10 μm. The thickness is adjusted to 500 μm, preferably 10 to 200 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 cells formed by the partition walls made 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 state of display information becomes clearer. Here, 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. Among these, a photolithography method using a resist film and a mold transfer method are preferably used.

Next, the powder fluid used as a display medium in the information display panel that is the subject 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, 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 to which the present invention is applied encloses a powder fluid that exhibits high fluidity in an aerosol state in which at least one is transparent, between opposed substrates, for example, solid particles in gas are stably suspended as a dispersoid 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, the pulverized fluid used in the present invention is a substance in the intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. This powder fluid can be in an aerosol state in particular, and in the information display panel of the present invention, a solid substance is used in a state of relatively stably floating as a dispersoid in the gas.

Next, the particles constituting the display medium in the information display panel that is the subject 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 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.

  Further, the particles constituting the display medium in 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 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 set to 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 proportion of particles below this is 10%. (Numerical value expressed in μm, d (0.9) is a numerical value expressed in μm for a particle size of 90% or less)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and the display medium can be moved uniformly.

  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 machine, 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.

In addition, when the display medium (particle group or powder fluid) of the present invention is used in a dry information display panel, it is important to manage the gas in the voids surrounding the particle group or powder fluid between the substrates, improving display stability. Contribute to. 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 and 2, electrodes 5 and 6 (when electrodes are provided inside the substrate), display medium (particle group or powder fluid) from the portion sandwiched between the opposing substrate 1 and substrate 2 in FIGS. ) A gas portion in contact with a so-called display medium (particle group or powdered fluid) excluding the occupied portion 3, the occupied portion of the partition wall 4, and the information display panel seal portion.
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 that is the subject of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the display medium in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. If it exceeds 70%, the movement of the display medium (in other words, particles constituting the display medium) is hindered, and if it is less than 5%, the contrast tends to be unclear.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to the following examples. In addition, the information display panel of the Example of this invention and the comparative example evaluated what produced by the following method according to the following reference | standard.

[Production of information display panel]
First, a transparent glass substrate with electrodes (7 cm × 7 cm □) was prepared, ribs were formed on the substrate, and partition walls were formed.
Ribs were formed as follows. A dry film photoresist NIT250 manufactured by Nichigo Morton, which is a photosensitive film, was laminated on a glass with ITO, and a partition wall having a height of 50 μm, a line of 30 μm, a space of 320 μm, and a pitch of 350 μm was formed by exposure and development. Next, a non-transparent substrate (glass epoxy) was prepared as a substrate with an ITO electrode (7 cm × 7 cm □, thickness: 100 μm) used as the back side substrate.

Next, two types of particle groups (particle group A and particle group B) having different colors and charging characteristics were prepared as display media.
Next, one of the substrates on which the partition walls are formed is transferred into a dry container having a humidity of 40% RH or less, and first, the particle group A is used as the first particle group to enter the container from the nozzle provided in the upper part of the container. The particle group A was filled by dispersing and spraying into the cells on the substrate placed at the bottom of the container and allowing them to fall freely.
Next, the charged particle group A was subjected to ion irradiation by an ion generator, so that the charged particle group A was neutralized. In Examples and Comparative Examples of the present invention, a corona discharge type ion generator (SJ-R036 manufactured by Keyence Corporation) or an air ion type ion generator (SJ-F010 manufactured by Keyence Corporation) was used.

Subsequently, the particle group B is dispersed as a second particle group in a container from another nozzle provided in the upper part of the container, and the inside of the cell on the substrate placed in the lower part of the container (already filled with the particle group A). The particle group A was overlaid and filled by spraying and free-falling.
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 superimposed on the substrate in which the particle group is filled and arranged in the cell, and the periphery of the substrate, the partition wall and the substrate are bonded with an epoxy adhesive, and the particle group is sealed for information display. A panel was produced.

[Evaluation of display function]
By applying a voltage of 250 V to the information display device incorporating the manufactured information display panel and reversing the potential repeatedly, a black to white solid image is repeatedly displayed, and the quality of the displayed solid image is visually observed. Evaluation was made by observation.

[Display medium]
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. In the above description, the names of the particle groups are the particle group A that is filled first, and the particle group B that is filled later.
The black particle group 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 carbon black (MA100 Mitsubishi Chemical Corporation), 4 parts by weight, 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 was an approximately spherical and negatively charged black particle group having an average particle diameter of 9.1 μm.
The white particles are 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 was spherical white particles having an average particle diameter of 8.5 μm and positively chargeable.

[Method of applying voltage]
FIG. 6 shows an example in which the black display medium particles 3Ba are dispersed and then the white display medium particles 3Wa are overlaid and dispersed, and the white particle group 3W is dispersed from the spray nozzle 11 into the cells on the substrate 1 (2). Then, when filling the white particle group 3W by free-falling, a high voltage power source is connected to the electrode 5 (6) of the substrate 1 (2).

<Example 1>
An information display panel was prepared by the above-described procedure (first, black particles were sprayed and filled, and after neutralizing with an air ion type ion generator, white particles were then sprayed and filled), and the display function was evaluated. The evaluation results are as shown in Table 1.

<Example 2>
First, an information display panel is prepared in the same manner as in Example 1 except that the white particles are sprayed and filled, and after neutralizing with an air ion type ion generator, the black particles are overlapped and charged. The display function was evaluated. The evaluation results are as shown in Table 1.

<Example 3>
First, the information display panel was prepared in the same manner as in Example 1 except that the black particle group was sprayed and filled, neutralized with a corona discharge type ion generator, and then the white particle group was overlapped and sprayed and filled. The display function was evaluated. The evaluation results are as shown in Table 1.

<Example 4>
First, an information display panel was prepared in the same manner as in Example 1 except that white particles were sprayed and filled, and after neutralizing with a corona discharge type ion generator, the black particles were overlapped and sprayed. The display function was evaluated. The evaluation results are as shown in Table 1.

<Example 5>
First, a black particle group is sprayed and filled, and after neutralizing with an air ion type ion generator, when a white particle group is piled and sprayed and charged, a high voltage power supply (MODEL615: Trek Japan) is connected to the substrate electrode, and +1 kV A voltage was applied. The evaluation results are as shown in Table 1.

<Example 6>
First, a white particle group was sprayed and filled, and after neutralizing with an air ion type ion generator, when the black particle group was overlapped and charged, a high voltage power source was connected to the substrate electrode, and a voltage of −1 kV was applied. The evaluation results are as shown in Table 2.

<Comparative Example 1>
First, an information display panel is prepared and displayed in the same manner as in Example 1 or Example 3 except that the black particle group is sprayed and filled, and the white particle group is stacked and filled without performing static elimination. The function was evaluated. The evaluation results are as shown in Table 1.

<Comparative example 2>
First, an information display panel was prepared in the same manner as in Example 2 or Example 4 except that the white particle group was sprayed and filled, and the black particle group was overlapped and filled without performing static elimination. The function was evaluated. The evaluation results are as shown in Table 1.

<Comparative Example 3>
First, the black particle group was sprayed and filled, and the white particle group was overlapped and filled without discharging. When spraying and filling the white particles, a high voltage power source was connected to the substrate electrode, and a voltage of +1 kV was applied. The evaluation results are as shown in Table 2.

<Comparative example 4>
First, the white particle group was sprayed and filled, and the black particle group was overlapped and filled without discharging. When spraying and filling the black particle group, a high voltage power source was connected to the substrate electrode, and a voltage of −1 kV was applied. The evaluation results are as shown in Table 2.

As described above, according to Example 1 to Example 6, after the particle group A is spray-filled and discharged, the particles constituting the particle group A and the particle group are formed by overlapping and charging the particle group B. The particles constituting B are prevented from aggregating with each other, the display medium (particle group) does not protrude from the cell, and the display medium can be satisfactorily filled. Spacing and parallelism were ensured, and good display information image quality was obtained.
On the other hand, according to Comparative Examples 1 to 4, since the display medium (particle group) protruded from the cell in many cases and the display medium adhered to the top of the partition wall, the information display panel was not manufactured.

  An information display panel and an information display device including the same according to the present invention include a display unit of a mobile device such as a notebook computer, a PDA, a mobile phone, and a handy terminal, an electronic paper such as an electronic book and an electronic newspaper, a signboard, a poster, a blackboard Billboards, calculators, home appliances, car supplies, card displays such as point cards, IC cards, electronic advertisements, electronic POPs, electronic shelf labels, electronic price tags, electronic musical scores, RF-ID device displays, etc. Is preferably used.

It is a figure which shows an example of the panel for information display used for the information display apparatus of this invention. It is a figure which shows the other example of the information display panel used for the information display apparatus of this invention. (A)-(e) is a figure for demonstrating the manufacturing method of the information display panel of this invention. (A)-(d) is a figure for demonstrating the manufacturing method of the information display panel of this invention. It is a figure which shows an example of the shape of the partition in the information display panel of the information display apparatus of this invention. It is a figure for demonstrating the method of applying a voltage to a board | substrate when manufacturing the information display panel of this invention.

Explanation of symbols

1, 2 Substrate 3 Display medium (particle group, powder fluid)
3W White display medium 3B Black display medium 3Wa White display medium particles 3Ba Black display medium particles 4 Bulkhead 5 Electrode 6 Electrode 11 Spray nozzle 12 Static neutralizer

Claims (4)

A plurality of cells partitioned by partition walls are formed between two opposing substrates at least one of which is transparent, and two types of display media having different charging characteristics are enclosed in the cells, and an electric field is applied to the display media. A method of manufacturing an information display panel that displays information such as an image by moving a display medium,
After filling the first display medium in the cell and before filling the second display medium, the first display medium filled in the cell is discharged, and then the second display medium is displayed on the first display medium. A method of manufacturing an information display panel, wherein the information display panel is filled in a stacked manner.   As a method of filling the first display medium and the second display medium, the first display medium and the second display medium are separately sprayed into the air from nozzles arranged on the substrate, and the substrate is free-falled. 2. The method for manufacturing an information display panel according to claim 1, wherein the second display medium is overlaid on the first display medium by using a method of filling the upper cell.   When the first display medium is discharged and then the second display medium is overlaid on the first display medium, a voltage having a sign opposite to the charging characteristic of the second display medium is applied to the substrate. The method for manufacturing an information display panel according to claim 1, wherein the second display medium is overlaid and filled on the first display medium.   4. The method for manufacturing an information display panel according to claim 1, wherein the display medium is a particle group or a powder fluid.

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