JP2006330707A - Method for manufacturing information display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an information display panel by which a predetermined amount of a display medium can be reliably sealed within a cell even when a display medium is to be sealed in a cell formed by barrier walls between opposing substrates. <P>SOLUTION: A method for manufacturing an information display panel is provided, the display panel which displays information such as an image by sealing at least one kind of display medium 3 composed of at least one kind of particles and having an optical reflectance and charging property in a cell 14 formed by barrier walls 4 between two opposing substrates 1, 2 at least one of which is transparent, applying an electric field to the display medium and thereby moving the display medium. The method has a display medium placing step of placing the display medium in the cell. which includes a display medium charge supporting step of supporting the charged display medium, a display medium arranging step of arranging the supported display medium according to an electrostatic latent image, and a display medium transfer/placing step of transferring/placing the arranged display medium into the cell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides at least one or more kinds of optical reflectance and chargeability composed of at least one kind of particles in a cell formed by a partition between two opposing substrates, at least one of which is transparent. The present invention relates to a method for manufacturing an information display panel that encloses a display medium and applies an electric field to the display medium to move the display medium to display information such as 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. 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 of repeated rewriting of information display is lacking. Have 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 a method for solving the various problems described above, an optical reflectance composed of at least one kind of particles in a cell formed by a partition wall between two opposing substrates, at least one of which is transparent. In addition, there is known an information display panel that encloses at least one type of display medium having charging properties and applies an electric field to the display medium to display information such as an image by moving 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” Proceedings, p.249-252

  In the method for manufacturing an information display panel described above, as a method of encapsulating a display medium (in other words, display medium particles constituting the display medium) between substrates, for example, a coating method in which the display medium is stretched on the panel substrate, A method of dispersing the display medium particles on the substrate by floating the display medium in the air by stirring, air blowing, etc., and passing the panel substrate through the display medium can be considered. Among these methods, the coating method has a problem that the display medium is less likely to adhere to the panel substrate, so that the filling amount (coating amount) is insufficient and uneven. In the spraying method, a plurality of cells are formed between the substrates and a partition provided to ensure a uniform spacing between the substrates is used to divide the space between the substrates into a plurality of cells, and a display medium is provided in each cell. When filling and sealing, the display medium is placed on the top of the partition wall, and when the two substrates are overlapped, the display medium is sandwiched between the overlap between the substrate and the partition or between the partition walls. Therefore, there is a problem that the distance between the substrates cannot be made uniform.

  An object of the present invention is to solve the above-described problems and ensure that a predetermined amount of display medium is contained in a cell even when the display medium is sealed in a cell formed by a partition between opposing substrates. It is intended to provide a method for manufacturing an information display panel that can be enclosed in a container.

  The method for producing an information display panel according to the present invention comprises an optical reflectance and charging comprising at least one kind of particles in a cell formed by a partition between two opposing substrates, at least one of which is transparent. In an information display panel manufacturing method for displaying information such as images by enclosing at least one type of display medium having a property and applying an electric field to the display medium, the display medium is a cell. The display medium filling process for filling the display medium includes a display medium charge carrying process for carrying a charged display medium, a display medium arranging process for arranging the carried display medium based on an electrostatic latent image, and an arranged display medium And a display medium transfer filling step of transferring and filling the inside of the cell.

  As a preferred example of the method for manufacturing the information display panel of the present invention, the pattern based on the electrostatic latent image in the display medium arranging step corresponds to the cell opening formed by the partition on the substrate, and is more than the cell opening. The display medium charge carrying step is performed by supplying the display medium charged from the display medium charge supply device to the display medium carrying roller, and the display medium arranging step is performed by the electrostatic latent image forming device. An electrostatic latent image having a predetermined pattern is formed on the surface of the photosensitive drum, and a display medium is arranged on the photosensitive drum based on the electrostatic latent image, and a display medium transfer filling process is arranged. The substrate having the cell is passed between the medium and the transfer device, and the display medium is transferred and filled in the cell, and the display medium filling process is continued by the number of types of the display medium to be filled. Set up The number of types of display media to be filled for each of the two substrates, the number of display medium filling steps being arranged in parallel, the display medium being a particle group or It may be a powder fluid.

  According to the method for manufacturing an information display panel of the present invention, when the display medium is filled in the cells formed by the partition walls between the information display panel substrates, there is no shortage and unevenness in the filling amount. An information display panel can be provided in which a display medium can be made uniform without a display medium being placed on the top of the display, and a display state having a good contrast can be obtained.

  First, the basic structure of the information display panel manufactured according to the manufacturing method of the present invention will be described. In the information display panel of the present invention, an electric field is applied to the display medium sealed between the opposing substrates. Along with the applied electric field direction, the charged display medium is attracted by the electric field force, the Coulomb force, or the like, and the display medium changes the moving direction according to the change in the electric field direction, thereby displaying information such as an image. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain stability when the display information is rewritten or when the display information is continuously displayed. Here, as the force applied to the particles constituting the display medium, in addition to the force attracting each other by the Coulomb force between the particles, an electric mirror image force 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 manufactured according to the manufacturing method 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 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. A black display medium 3B composed of a medium 3W and a particle group is enclosed between the substrate 1 and the substrate 2, and the substrates 1 and 2 according to the electric field generated by using some voltage applying means between the substrates. The black display medium 3B is visually recognized by the observer and black display is performed, or the white display medium 3W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1B, the partition walls 4 are formed between the substrates 1 and 2, and a plurality of rectangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)

  In the example shown in FIGS. 2A and 2B, at least two types of display media 3 (here, white display consisting of a group of particles) having different optical reflectance and charging characteristics composed of at least one type of particles. 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. 2B, a partition wall 4 is formed between the substrates 1 and 2, and a plurality of quadrangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)

In the example shown in FIGS. 3A and 3B, a display medium 3 (here, a white display medium consisting of a group of particles) having one kind of optical reflectance and chargeability composed of at least one kind of particles. 3W) is moved in parallel with the substrates 1 and 2 according to the electric field generated by applying a voltage between the electrode 5 and the electrode 6 provided on the substrate 1, and the white display medium 3W is moved to the observer. The color of the electrode 6 or the substrate 1 (color expressed by an optical reflectivity different from that of the white display medium 3W) is displayed by making the viewer visually recognize the electrode 6 or the substrate 1 Is displayed. In the example shown in FIG. 3B, a partition wall 4 is formed between the substrates 1 and 2, and a plurality of rectangular cells are provided in a lattice shape. (The partition in front of the figure is omitted.)
The electrode may be provided outside the substrate or may be provided so as to be embedded in the substrate.

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

  In manufacturing the information display panel having the above-described configuration, the present invention is characterized in that the display medium filling step of filling the display medium in the cell includes a display medium carrying step for carrying a charged display medium, and a carried display. The present invention consists of a display medium arranging step for arranging the medium based on the electrostatic latent image, and a display medium transfer filling step for transferring and filling the arranged display medium into the cell. Hereinafter, the manufacturing method of the information display panel of the present invention will be described in more detail with reference to the drawings.

  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, the display medium filling process and the panel bonding process following that are characteristic of the manufacturing method of the present invention. In the example shown in FIG. 4, first, a charged display medium 3 (here, a white display medium) is supplied from the display medium charge supply device 11 to the display medium support roller 12 (display medium charge support process).

  Next, an electrostatic latent image of a predetermined pattern (for example, a pattern corresponding to the cell pattern of the cells 14 formed by the partition walls 4 on the substrate 1 of the panel) is formed on the surface of the photosensitive drum 15 by the electrostatic latent image forming device 13. And the display medium 3 carried on the surface of the photoconductive drum 15 by the display medium carrying roller 12 is rotated and supplied to the surface of the photoconductive drum 15, whereby a predetermined electrostatic latent image is formed on the photoconductive drum 15. The display media 3 are arranged and placed along the pattern (display medium arranging step).

  A conveyance belt 16 that conveys the panel substrate 1 runs under the photosensitive drum 15, and a display medium arranged on the photosensitive drum 15 is disposed on the back side of the conveyance belt 16 that faces the photosensitive drum 15. A transfer device 17 for transferring 3 to the substrate 1 is provided. When the panel substrate 1 transported by the transport belt 16 passes between the photosensitive drum 15 and the transfer device 17, the display medium 3 arranged and mounted on the photosensitive drum 15 becomes a cell on the panel substrate 1. 14 is transferred and filled in (display medium transfer filling step).

  After the display medium filling process described above is completed, an information display panel can be obtained by bonding the other substrate 2 to the substrate 1 filled with the predetermined display medium 3 in the cell 14 ( Panel bonding process).

  In the above-described example, the display medium 3 on the display medium carrying roller 12 and the photosensitive drum 15 is described as a single layer, but it is not necessary to be a single layer, and two or more layers depending on the amount filled in the cell 14. It can also be. Further, an example is shown in which the electrostatic latent image on the photosensitive drum 15 is made to correspond to the cell pattern, in other words, the portion corresponding to the partition wall 4 is not provided with the electrostatic latent image and the display medium 3 is not provided. However, the pattern of the electrostatic latent image is not limited to the cell pattern, and the electrostatic latent image may be given so that the display medium 3 is arranged on the entire surface. Furthermore, the pattern of the electrostatic latent image corresponds to the opening of the cell 14 formed by the upper partition 4 on the substrate, and can be a region narrower than the cell opening.

  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, the display medium filling process shown in FIG. 4 is continuously performed, the black display medium 3B and the white display medium 3W are filled between the panel substrates, and then the panels are bonded together. . Moreover, FIG. 6 is a figure for demonstrating the further another example of the manufacturing method of the information display panel of this invention. In the example shown in FIG. 6, two display medium filling steps shown in FIG. 4 are arranged side by side, and the black display medium 3B and the white display medium 3W are separately filled into two panel substrates, and then the panels are bonded together. It shows a state.

  FIGS. 7A, 7B to 10A, 10B are diagrams for explaining suitable examples of the shape of the cell opening and the electrostatic latent image pattern corresponding thereto. All correspond to the openings (FIGS. 7A, 8A, 9A, and 10A) of the cell 14 formed by the upper partition wall 4 described as the above-described preferred example. In this example, the pattern of the electrostatic latent image (FIG. 7B, FIG. 8B, FIG. 9B, and FIG. 10B) is narrower than the cell opening.

  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 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. 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.

  As an electrode forming material for providing an electrode on an information display panel, metals such as aluminum, silver, nickel, copper and gold, indium tin oxide (ITO), indium oxide, conductive tin oxide, antimony tin oxide ( ATO), conductive metal oxides such as conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene are exemplified and used as appropriate. 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. The electrode provided on the display surface side substrate 2 which is on the viewing side and needs to be transparent needs to be transparent, but the electrode provided on the back side substrate 1 does not need to be transparent. In any case, the above-mentioned material that can be patterned and is electrically conductive 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 1 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 height and width of the partition walls provided on the substrate are appropriately set according to the type of display medium involved in display, and are not generally limited. However, the partition wall width is 2 to 100 μm, preferably 3 to 50 μm, and the partition wall height is 10 It is adjusted to ˜500 μm, preferably 10 to 200 μm. The cell shape of the information display panel obtained by superimposing the display side substrate and the back side substrate may be various shapes as illustrated in FIG. 11 depending on the partition wall shape. It is better to make the portion corresponding to the partition cross section visible from the display surface side (the area of the cell frame formed by the partition width) as small as possible, and the display state becomes clearer.

  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 pulverulent fluid exhibits a state that is so fluid that it does not form an angle of repose, which is an index indicating the fluidity of the powder. Coulomb force is generated by an electric field formed by applying a low voltage, etc. It can be easily and stably moved.
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, it is used as a display medium that can easily create a state in which a solid substance floats relatively stably as a dispersoid in a 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.

As extender pigments, barite powder, barium carbonate, clay, silica, white carbon,
There are 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 above colorant can be blended to produce display medium particles having a desired color.

  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. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders movement as a display medium.

Furthermore, in the present invention, regarding the particle size distribution of the particles for each display medium, 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 indicating 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 size of 90% or less.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and uniform movement as a display medium is possible.

  Furthermore, regarding the correlation of the particle particles for each display medium, 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 50 or less, preferably 10 or less. Is important. 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 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 inventors of the present invention have been able to evaluate the range of proper charging characteristics of display medium particles by measuring the charge amount of display medium particles using the same carrier particles in the blow-off method. I found it.

Furthermore, when the information display panel manufactured by the present invention is used as a dry information display panel for driving a display medium in an air space, it is important to manage the gas in the voids surrounding the display medium, and display stability. Contributes to improved performance. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, with respect to the gas humidity in the void portion.
1A, 1B, 3A, and 3B, the gaps are defined by the electrodes 5 and 6 (the electrodes are placed on the inside of the substrate). Gas portion in contact with the so-called display medium, excluding the occupied portion of the display medium 3 (particle group or powder fluid), the occupied portion of the partition wall 4 (when the partition wall is provided), and the seal portion of the information display panel. Shall be pointed to.
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.
In the case of a dry information display panel, the volume occupancy 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 is hindered, and if it is less than 5%, the contrast tends to be unclear.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples of 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.

"Preparation of display media"
In Examples and Comparative Examples, black and white two-color display media (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), IPDI crosslinker Excel Hardener HX (manufactured by Asia), 4 parts by weight of carbon black (MA100 Mitsubishi Chemical), charge control. 2 parts by weight of the agent Bontron E89 (made by Orient Chemical Co., Ltd.) is added, kneaded, pulverized by a jet mill, and mechanical impact force is applied using a hybridizer device (manufactured by 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. A solution obtained by dispersing 20 parts by weight of titanium oxide, which has been made lipophilic by treatment with an agent, is suspended and polymerized in a 10-fold amount of a 0.5% aqueous surfactant (sodium lauryl sulfate) solution, filtered and dried. Then, it was prepared using a classifier (MDS-2: Nippon Numatic Industries). The produced particle group B was a positively charged spherical white particle having an average particle diameter of 8.5 μm.

"Production of panel substrate"
A glass transparent substrate with ITO electrodes (7 cm × 7 cm □) was prepared, ribs having a height of 50 μm were formed on one substrate, and square-shaped and grid-shaped partition walls were formed.
The partition wall was formed as follows. A dry film photoresist NIT250 made by Nichigo Morton, which is a photosensitive film, was laminated on a glass with ITO, and a partition wall having desired lines of 30 μm, spaces of 320 μm, and pitch of 350 μm was formed by exposure and development. As the other substrate, a glass transparent substrate (7 cm × 7 cm □) with an ITO electrode was prepared.

<Example 1>
Two kinds of particle groups (particle group A and particle group B) having different optical reflectivity and charging characteristics are continuously provided in the cell of one substrate on which the partition walls are formed by the display medium filling step shown in FIG. 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, and the outer peripheral portion around the substrate is bonded and sealed with an epoxy adhesive to display the display medium (particle group A and particle group). B) was enclosed to produce an information display panel.

<Example 2>
Two types of particle groups (particle group A and particle group B) having different optical reflectance and charging characteristics are formed in the cells of the substrate on which the partition walls are formed and the partition walls by the display medium filling step shown in FIG. In the other substrate cell, not filled separately. 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 two substrates in which the particle groups are filled and arranged in the cell are overlapped with each other, and the outer peripheral portion around the substrate is bonded and sealed with an epoxy adhesive to display media (particle group A and particle group B). Was sealed to produce an information display panel.

<Comparative Example 1>
Using a powder electrostatic spraying device, a predetermined amount of display medium (particle group A and particle group B) is sprayed in the cell of the substrate in the order of particle group A and particle group B directly on the substrate on which the partition walls are formed. An information display panel was produced in the same manner as in Example 1 except that the filling was performed. That is, the information display panel was manufactured by filling the display medium without using the display medium filling step of the present invention.

  For Examples 1 and 2 and Comparative Example 1 described above, the situation after filling the display medium and the situation of the panel on which the substrates were superimposed were examined. The results are shown in Table 1 below.

  From the results in Table 1, the following can be understood. Example 1 using an information display panel produced by filling a display medium according to a display medium filling process comprising a display medium charging and carrying process, a display medium arranging process, and a display medium transfer filling process of the present invention. In the information display panel 2, the display medium was not placed on the partition when the display medium was filled, and there was no problem even if the substrates were stacked as they were. On the other hand, in Comparative Example 1 in which the display medium is filled using the granule charging / spreading device that does not use the filling step of the present invention, the display medium is placed on the partition wall when the display medium is filled, and the substrate is directly superimposed on the panel. There was a problem with it.

  Information display panels manufactured by the manufacturing method of the present invention include display units of mobile devices such as notebook computers, PDAs, mobile phones, and handy terminals, electronic papers such as electronic books and electronic newspapers, signboards, posters, and blackboards. Bulletin boards, calculators, home appliances, automotive supplies, etc., point cards, card displays such as IC cards, electronic advertisements, information boards, electronic POPs (Point Of Presence, Point Of Purchase advertising), electronic shelf labels, electronic price tags It is suitably used for electronic musical scores, display units of RF-ID devices, and the like.

(A), (b) is a figure which shows the structure of an example of the information display panel used as the object of the manufacturing method of this invention, respectively. (A), (b) is a figure which shows the structure of the other example of the information display panel used as the object of the manufacturing method of this invention, respectively. (A), (b) is a figure which shows the structure of the further another example of the information display panel used as the object of the manufacturing method 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 for demonstrating the further another example of the manufacturing method of the information display panel of this invention. (A), (b) is a figure for demonstrating a suitable example of a cell opening part shape and an electrostatic latent image pattern corresponding to it, respectively. (A), (b) is a figure for demonstrating the other suitable example of a cell opening part shape and an electrostatic latent image pattern corresponding to it, respectively. (A), (b) is a figure for demonstrating another suitable example of a cell opening part shape and an electrostatic latent image pattern corresponding to it, respectively. (A), (b) is a figure for demonstrating another suitable example of a cell opening part shape and an electrostatic latent image pattern corresponding to it, respectively. It is a figure which shows an example of the shape of the partition in the information display panel used as the object of the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Substrate 3 Display medium 3W White display medium 3B Black display medium 4 Bulkhead 5, 6 Electrode 11 Display medium charge supply device 12 Display medium carrying roller 13 Electrostatic latent image forming device 14 Cell 15 Photosensitive drum 16 Conveying belt 17 Transfer apparatus

Claims (8)

  At least one type of display medium having optical reflectivity and chargeability composed of at least one type of particles is enclosed in a cell formed by a partition between two opposing substrates, at least one of which is transparent. In the method of manufacturing an information display panel that displays information such as an image by moving the display medium by applying an electric field to the display medium, the display medium filling step of filling the display medium in the cell is charged. Display medium charge carrying process for carrying display medium, display medium arranging process for arranging supported display medium based on electrostatic latent image, and display medium transfer for transferring arranged display medium into cell and filling A method for manufacturing an information display panel, comprising: a filling step.   The information display according to claim 1, wherein the pattern based on the electrostatic latent image in the display medium arranging step corresponds to a cell opening formed by the partition on the substrate and is an area narrower than the cell opening. Panel manufacturing method.   3. The method for manufacturing an information display panel according to claim 1, wherein the display medium charge carrying step is performed by supplying a display medium charged from a display medium charge supply device to a display medium carrying roller. .   The display medium arranging step is performed by forming an electrostatic latent image of a predetermined pattern on the surface of the photosensitive drum by an electrostatic latent image forming apparatus and arranging the display medium on the photosensitive drum based on the electrostatic latent image. The method for manufacturing an information display panel according to any one of claims 1 to 3, wherein:   The display medium transfer filling step is performed by passing a substrate having cells between the arranged display media and a transfer device, and transferring and filling the display medium in the cells. The manufacturing method of the information display panel of any one of 1-4.   6. The method for manufacturing an information display panel according to claim 1, wherein the display medium filling step is continuously provided by the number of types of display media to be filled.   The display medium filling step is provided for each of two substrates by the number of types of display media to be filled, and the display medium filling step is arranged in parallel. A method for producing the information display panel according to claim 1.   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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