JP2007065537A - 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 with which packing of a display medium can be efficiently performed to a substrate. <P>SOLUTION: In the manufacturing method of the panel for information display wherein the display medium is encapsulated between two substrates at least one of which is transparent and the display medium is transferred by applying an electric field to the display medium to display information, voltage is applied between an ejection part 12 and a substrate 1 to form the electric field when the display medium 3 is ejected from the ejection part 12 and accumulated on the substrate 1. Preferably, a potential having a polarity reverse to the charge polarity of the display medium is applied to the substrate or a potential having a polarity reverse to the charge polarity of the display medium is applied to the substrate by disposing the substrate on a supporting plate and applying voltage between the supporting plate and the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention manufactures an information display panel that displays information such as an image by moving a display medium by enclosing the display medium between two transparent substrates and applying an electric field to the display medium. It is about the method.

  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 inject the charge into the conductive particles at a constant rate, so that the stability in rewriting display information is lacking. There is also.

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

  When manufacturing the above-described conventional information display panel, a free-fall method using a spacer sprayer of a liquid crystal display panel is used to fill a display medium with cells formed between substrates or between substrates. . FIG. 7 is a diagram for explaining an example of a conventional free fall method. In the example shown in FIG. 7, a nozzle 52 connected to a spacer spreader (not shown) via a pipe 56 is provided as an ejection part of the display medium 53 in the upper part in the container 51, and the lower part in the container 51 is provided. A substrate 55 (or a substrate in which cells are formed by partition walls) is disposed on the support plate 54. In this state, the display medium 53 is sprayed from the nozzles 52, and the display medium 53 is dropped freely to be volumed on the substrate 55, thereby filling the display medium 53 onto the substrate 55.

  In the above-described conventional filling of the display medium by the free fall method, the nozzle 52, the substrate 55, and the support plate 54 are grounded, and the filling is performed especially when the charge amount of the display medium 53 is low. Since the display medium 53 is deposited by gravity, there is a problem that it is very time consuming and inefficient. In particular, when a powdered fluid, which will be described later in detail, is used as a display medium, the conventional free-fall method has a problem that it takes a long time to fill due to its excellent floatability.

  An object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing an information display panel that can efficiently fill a display medium with a substrate.

  In the method for manufacturing an information display panel according to the present invention, a display medium is sealed between two substrates, at least one of which is transparent, and an electric field is applied to the display medium, thereby moving the display medium to display information such as an image. In the manufacturing method of the information display panel to be displayed, when the display medium is ejected from the ejection part and deposited on the substrate, an electric field is formed by applying a voltage between the ejection part and the substrate. Is.

  As a preferred example of the method for manufacturing the information display panel of the present invention, a potential having a polarity opposite to the charging polarity of the display medium is applied to the substrate, the substrate is disposed on the support plate, and the support plate and the substrate are arranged. In some cases, a potential having a polarity opposite to the charging polarity of the display medium is applied to the substrate.

  According to the present invention, an electric field is formed by applying a voltage between the ejection unit and the substrate, so that not only the display medium composed of particles but also the display medium composed of powdered fluid with respect to the substrate. Also, the display medium can be efficiently filled. In particular, by forming an electric field so that the substrate has a polarity opposite to that of the charged display medium, more preferably, the substrate is disposed on the support plate, and a voltage is applied between the support plate and the substrate. Since the display medium can be selectively transferred onto the substrate by Coulomb force by applying a potential having a polarity opposite to the charged polarity of the display medium to the substrate, the display medium can be more efficiently filled. it can. Note that the distance between the discharge portion and the substrate is preferably short in order to increase the electric field strength.

  First, a basic configuration of an information display panel that is an object of the manufacturing method of the present invention will be described. In the information display panel which is an object of the present invention, an electric field is applied to a display medium sealed between two opposing substrates. Along with the applied electric field direction, the charged display medium is attracted by the electric field force or Coulomb force, etc., and the display medium changes the moving direction by the electric field direction change due to the potential switching, thereby displaying information such as an image. Made. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain stability when rewriting the display repeatedly or when displaying the display information continuously. Here, as the force applied to the particles constituting the display medium, in addition to the force 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 an information display panel which is a manufacturing method object of the present invention will be described with reference to FIGS. 1 (a) and (b) to FIGS. 3 (a) and 3 (b).

  In the example shown in FIGS. 1A and 1B, at least two kinds of display media 3 (here, white display medium particles 3Wa) having at least one kind of particles and having different optical reflectance and charging characteristics. A white display medium 3W made up of a group of particles and a black display medium 3B made up of particles of a black display medium particle 3Ba), and an electrode 5 provided inside the substrate 1 and an electrode 6 provided inside the substrate 2; In accordance with the electric field generated by applying a voltage between them, the substrate is moved perpendicularly to the substrates 1 and 2 so that the black display medium 3B is visually recognized by the observer to display black or the white display medium 3W. Is displayed in white by the observer. In the example shown in FIG. 1B, in addition to the example shown in FIG. 1A, a partition 4 is provided between the substrates 1 and 2, for example, in the form of a lattice to form a cell. In addition, in FIG. 1B, the partition in front is omitted.

  In the example shown in FIGS. 2A and 2B, at least two or more types of display media 3 (here, white display medium particles 3Wa) having different optical reflectance and charging characteristics composed of at least one type of particles. An electrode 5 provided outside the substrate 1 and an electrode 6 provided outside the substrate 2, and a white display medium 3 W made up of a particle group and a black display medium 3 B made up of particles of a black display medium particle 3Ba. In accordance with the electric field generated by applying a voltage between them, the substrate is moved perpendicularly to the substrates 1 and 2 so that the black display medium 3B is visually recognized by the observer to display black or the white display medium 3W. Is displayed in white by the observer. In the example shown in FIG. 2B, in addition to the example shown in FIG. 2A, for example, a partition 4 is provided between the substrates 1 and 2 to form a cell. Further, in FIG. 2 (b), the front partition is omitted.

  In the example shown in FIGS. 3 (a) and 3 (b), one type of display medium 3 (here, particles of white display medium particles 3Wa) having optical reflectivity and chargeability composed of at least one type of particles. A white display medium 3 </ b> W consisting of a group) perpendicular to the substrates 1 and 2 according 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. The white display medium 3 </ b> W is visually recognized by the observer to perform white display, or the color of the electrode 6 or the substrate 1 is visually recognized by the observer to display the color of the electrode 6 or the substrate 1. ing. In the example shown in FIG. 3B, in addition to the example shown in FIG. 3A, for example, a grid-like partition wall 4 is provided between the substrates 1 and 2 to form a cell. Moreover, in FIG.3 (b), the partition in front is abbreviate | omitted.

  The above description is similarly applied to the case where the white display medium 3W including the particle group is replaced with the white display medium including the powder fluid and the black display medium 3B including the particle group is replaced with the black display medium including the powder fluid. I can do it.

  FIG. 4 is a diagram for explaining an example of a method for manufacturing an information display panel according to the present invention. In the example shown in FIG. 4, a nozzle 12 serving as a discharge unit for the display medium 3 is provided in the upper portion of the container 11, and the substrate 1 (or a substrate in which cells are formed by the partition walls 4) on the lower support plate 13 in the container 11. 1) is arranged. Reference numeral 14 denotes a pipe for supplying the display medium 3 to the nozzle 12. A feature of the present invention is that an electric field is formed by applying a voltage between the nozzle 12 and the substrate 1 when the display medium 3 is ejected from the nozzle 12 and deposited on the substrate 1.

  That is, in the example shown in FIG. 4, since the display medium 3 is made of a negatively chargeable particle group, a power source (not shown) is used so that the nozzle 12 has a potential of −100 V and the substrate 1 and the support plate 13 are grounded. Voltage is applied. Therefore, in this example, the substrate 1 and the support plate 13 have a potential of +100 V having a polarity opposite to that of the display medium 3 made of the negatively chargeable particle group. In order to increase the generated electric field strength, it is preferable that the distance between the nozzle 12 serving as the discharge portion of the display medium 3 and the substrate 1 is short.

  In this state, the display medium 3 supplied through the pipe 14 is ejected from the nozzle 12 and deposited on the substrate 1, whereby the display medium 3 is placed on the substrate 1 (in the example in which cells are provided, in the cells on the substrate 1. ). At that time, since an electric field indicated by an arrow is generated from the nozzle 12 toward the substrate 1, the display medium 3 can be selectively transferred onto the substrate 1 by Coulomb force due to the action of the electric field. As a result, the display medium 3 can be efficiently deposited on the substrate 1.

  In addition, when using two types of display media 3 of the white display medium 3W and the black display medium 3B which are mutually different in charging polarity as the display medium 3 to be filled, for example, the above-described filling process is performed using the white display medium 3W and the black display medium 3B. By repeating twice, it is possible to fill a display medium of two colors. At that time, the electric field between the nozzle 12 and the substrate 1 may be reversed in accordance with the charging polarity of the display medium 3.

  FIG. 5 is a view for explaining another example of the method for producing the information display panel of the present invention. In the example shown in FIG. 5, under the same configuration as in FIG. 4, a power source (not shown) is used so that the nozzle 12 has a potential of −200 V, the substrate 1 has a potential of +200 V, and the support plate 13 is grounded. A voltage is applied. Thus, similarly to the relationship between the nozzle 12 and the substrate 1, a potential having a polarity opposite to the charging polarity of the display medium 3 can be applied to the substrate 1 between the support plate 13 and the substrate 1. In the example shown in FIG. 5, compared to the example shown in FIG. 4, the substrate 1 has a potential of +400 V, so that the electric field from the nozzle 12 toward the substrate 1 can be made stronger. An electric field from the plate 13 toward the substrate 1 can also be generated, and the display medium 3 can be more selectively transferred onto the substrate 1.

  In the example shown in FIG. 4 and FIG. 5, the voltage is applied so that the potential of each member becomes −200 V, −100 V, and 200 V, but this is an example, and the absolute value is limited to these values. It will never be done.

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

  As for the substrate, at least one substrate is the transparent substrate 2 from which the color of the display medium 3 can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The substrate 1 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and glass and quartz. An inorganic sheet having no flexibility is mentioned. The thickness of the substrate is preferably from 2 to 5000 μm, more preferably from 5 to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, it will be a thin information display panel. Is inconvenient.

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

The shape of the partition walls 4 provided on the substrate as required is appropriately set appropriately depending on the type of display medium involved in display, the shape and arrangement of electrodes to be arranged, and is not limited in general. The height of the partition is adjusted to 100 to 100 μm, preferably 3 to 50 μm, and the height of the partition wall to 10 to 100 μm, preferably 10 to 50 μm.
In forming the partition wall, a both-rib method in which ribs are formed on each of the opposing substrates 1 and 2 and then bonded, and a single-rib method in which ribs are formed only on one substrate are conceivable. In the present invention, any method is preferably used.
As shown in FIG. 6, the cells formed by the partition walls made up of these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the plane of the substrate. And a mesh shape. It is better to make the portion corresponding to the cross section of the partition wall visible from the display surface side (the area of the cell frame) as small as possible, and the display becomes clearer.
Examples of the method for forming the partition include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Any of these methods can be suitably used for the information display panel of the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.

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

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

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

The information display panel of the present invention encloses a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, in a gas between opposing substrates, at least one of which is transparent. Yes, 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 a display medium in the present invention is a substance in an intermediate state between fluid and particles that exhibits fluidity by itself without borrowing the force of gas or liquid. It is. This powder fluid can be in an aerosol state in particular, and in the information display panel of the present invention, it is used as a display medium in a state where a solid substance floats relatively stably as a dispersoid in the gas.

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

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

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

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

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

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

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

Examples of inorganic additives include titanium oxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, Examples include bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.
These pigments and inorganic additives can be used alone or in combination. Of these, carbon black is particularly preferable as the black pigment, and titanium oxide is preferable as the white pigment.

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

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

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

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

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

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

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

The distance between the substrates in the information display panel that is the subject of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the display medium in the 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.

  An information display panel subject to the present invention is a display unit of a mobile device such as a notebook computer, PDA, mobile phone, handy terminal, electronic paper such as an electronic book or an electronic newspaper, a signboard, a poster, a bulletin board such as a blackboard, a calculator Appropriately used for display units for home appliances, automobiles, etc., card display units for point cards, IC cards, etc., electronic advertisements, electronic POPs, electronic price tags, electronic shelf labels, electronic musical scores, display units for RF-ID devices, etc. It is done.

(A), (b) is a figure which shows an example of the information display panel used as the object of this invention, respectively. (A), (b) is a figure which shows the other example of the information display panel used as the object of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel used as the object of this invention, respectively. It is a figure for demonstrating an example of the manufacturing method of the information display panel of this invention. It is a figure for demonstrating the other example of 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 used as the object of this invention. It is a figure for demonstrating an example of the conventional free fall method.

Explanation of symbols

1, 2 Substrate 3 Display medium (particle group, powder fluid)
3W White display medium 3Wa White display medium particle 3B Black display medium 3Ba Black display medium particle 4 Bulkhead 5, 6 Electrode 11 Container 12 Nozzle 13 Support plate 14 Piping

Claims (3)

  In a method for manufacturing an information display panel in which a display medium is sealed between two transparent substrates and an electric field is applied to the display medium to display information such as an image by moving the display medium. A method for manufacturing an information display panel, wherein an electric field is formed by applying a voltage between a discharge unit and a substrate when a medium is discharged from a discharge unit and deposited on a substrate.   2. The method for manufacturing an information display panel according to claim 1, wherein a potential having a polarity opposite to the charging polarity of the display medium is applied to the substrate.   The substrate is disposed on the support plate, and a voltage having a polarity opposite to the charging polarity of the display medium is applied to the substrate by applying a voltage between the support plate and the substrate. 2. A method for producing the information display panel according to 2.

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