JP2006227069A - Big screen display plate using reversible type information display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a big screen display plate using reversible type information display panels capable of suppressing manufacturing costs and man-hours of the big screen display plate satisfactorily low and effectively suppressing the consumption of resources. <P>SOLUTION: In the big screen display plate 1 which has, as display parts 5 and 6, reversible and dry type information display panels 2 and 3 and wherein a display mediums are encapsulated in a closed space between two substrates which are opposed to each other and at least one of which is transparent and the display medium are moved by an electric field formed by charges formed on the surfaces of the substrates to display necessary information on the transparent substrate side, (1) two kinds of mediums having colors and charge characteristics different from each other are used, (2) an average particle diameter of particles of the display mediums used for the information display panels is specified to be in the range of 3 to 10 μm and (3) total thickness of the information display panels is specified to be ≥10 μm and <1 mm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, two types of display media having different colors and charging characteristics are sealed in a sealed space between two substrates facing each other and at least one of which is transparent, and the display media are formed on the substrate surface. The present invention relates to a large-screen display plate using a reversible and dry information display panel as a display unit, which is moved by an electric field generated by the generated charges and displays necessary information on a transparent substrate side.

  For example, in addition to titles, subjects, etc. when performing lectures, speeches, research presentations, etc. In order to widely inform the audience, visitors, etc., a large screen display board, which serves as a display section for displaying the “title”, is placed in a standing position, suspended, mounted and fixed on the podium or stage. It has been widely performed conventionally. Conventionally, it has been common to post the “title” by fixing or fixing a paper, a plastic sheet, etc., on which the “title” is handwritten or printed, to the display board body. The same was true for Koza and others.

  However, according to the conventional posting using the paper, plastic sheet, etc. describing the “title”, there is a problem that the consumption of resources is forced by discarding the display paper such as the paper after fulfilling the role. there were. In addition, when writing “title” or other required information on a blackboard, whiteboard, etc., it is necessary to have another means for erasing information after use, and the surrounding stains associated with erasing information There was also a problem that it became inevitable.

On the other hand, as an information display panel capable of repeatedly displaying information such as an image, the present applicant encloses a display medium in a space between two substrates, at least one of which is transparent. A reversible information display panel that can be moved in an electric field to display necessary information on the transparent substrate side has been proposed (see, for example, Patent Document 1). This information display panel moves the display medium based on the formation of electric charges such as an electrostatic latent image on the substrate, the Coulomb force between the particles for the display medium constituting the display medium, the electric image force with the electrode, the molecule Even if there is no electric field between the substrates due to the interatomic force, liquid bridging force, gravity, etc., the display information can be maintained over a long period of time, so that it has the advantage of exhibiting excellent display storage stability. Therefore, after displaying required information such as figures, symbols, images, etc. on the transparent substrate for a long time, it can be easily erased and rewritten, and can be used repeatedly. Therefore, it is suitably used for the above-mentioned large screen display board. there is a possibility.
JP 2004-341123 A

  However, if the conventional information display panel is used for a large-screen display board, there is a problem that clear information display cannot be performed, or display information cannot be erased and rewritten reliably. Then, it could not be used for the large screen display board which is the subject of the present invention.

  The object of the present invention is to solve the above-mentioned problems, reduce the manufacturing cost and man-hour of a large screen display board sufficiently low, and use a large-sized reversible information display panel that can effectively suppress resource consumption. It is intended to provide a screen display board.

  A large screen display board using the reversible information display panel of the present invention encloses a display medium in a sealed space between two substrates facing each other and at least one of which is transparent, A large-screen display plate having a reversible and dry information display panel as a display unit, which is moved by an electric field generated by an electric charge formed on the substrate surface and displays necessary information on the transparent substrate side. ) Use two types of display media with different colors and charging characteristics, (2) Set the average particle diameter of the particles for display media used in the information display panel in the range of 3 to 10 μm, and (3) Total thickness of the information display panel Is 10 μm or more and less than 1 mm.

  Here, preferably, the thickness of at least one of the two substrates is 0.4 mm or less, and the distance between the substrates formed by the two substrates facing each other is 0.1 mm or less. Preferably, each substrate is made of a plastic material. More preferably, a particle group or a powder fluid is used as the display medium.

  In the large screen display board using the reversible information display panel of the present invention, first, the clear information display that the conventional information display panel has cannot be performed, and the display information cannot be erased and rewritten reliably. (1) Two types of display media having different colors and charging characteristics are used, and (2) The average particle size of the display medium particles used in the information display panel is in the range of 3 to 10 μm. (3) This is solved by setting the total thickness of the information display panel to 10 μm or more and less than 1 mm. Thus, display information can be rewritten reliably by using charge forming means that can form charges on the information display panel substrate (for example, means for forming charges as an electrostatic latent image by a photoconductor or means for forming charges by ion flow). It can be done. Therefore, in a large screen display board using the reversible information display panel having the above configuration as a display unit, it is possible to display new information as many times as necessary after erasing the displayed information without fail. It is no longer necessary to perform predetermined printing or the like, and the cost and the man-hours required for the printing can be greatly reduced, and the consumption of resources can be sufficiently prevented.

  By the way, in the information display panel used for the large-screen display board of the present invention, making each substrate made of a plastic material can not only make the panel sufficiently thin and lightweight, but also the large size of the present invention. This is also an effective method for securely erasing the displayed information necessary for the screen display board and then displaying new information clearly.

  Therefore, according to the large screen display board of the present invention, it is not necessary to perform predetermined printing on a large number of sheets, and the manufacturing cost of the large screen display board and the work man-hours for it can be greatly suppressed. The resource consumption can be sufficiently prevented under the reuse of the display unit.

  FIG. 1 is a diagram showing an example of a large screen display board using the reversible information display panel of the present invention. A large screen display board placed in a standing posture on a podium, for example, under the action of a leg (not shown). An exemplary front view is shown.

  This large screen display board 1 can of course be constructed by attaching a single information display panel whose structure will be described in detail later to the display board body, but here, as shown in the figure surrounded by a broken line, Two reversible information display panels 2 and 3 are attached to a single display plate body 4 so as to be aligned with each other, thereby constituting a large screen display plate 1.

  And here, the first information display panel 2 in which the front side is a transparent substrate and information can be written and rewritten as required is caused to function as the presentation display section 5 as an example of the “title”, The same second information display panel 3 is caused to function as a lecturer display unit 6 as an example of the “subject”.

  In such a large screen display board 1, the combination of the two colors of the information display medium enclosed in the display panels 2 and 3 is a dark and dark color in order to increase the contrast at the time of visual observation and improve the visibility. It is preferable to use a combination with a light color, but when the colors to be combined are different between the display panels 2 and 3, the visibility of display information on the display panel 1 is further enhanced. be able to. Further, the display unit 5 and the display unit 6 can perform different color displays (area colors). For example, the display unit 5 can be configured by a combination of white and blue, and the display unit 6 can be configured by a combination of white and red.

  In such a large screen display board 1, at least one of the display of the word “presentation” on the display section 5 of “title” and the display of the word “instructor” on the display section 6 of “subject” is displayed. When there is no need for change, it is possible to make it a permanent display such as a print display. According to this, at least the information display panels 2 and 3 can be made smaller.

By the way, in the large screen display board 1 shown in the figure, the “subject” display section 6 is arranged side by side on the “title” display section 5, but this “subject” display section 6 is omitted from the display board 1. Is also possible.
Further, in the figure, “title” and “subject” are displayed on each of the two display sections 5 and 6 including the two information display panels 2 and 3, respectively. One information display panel can function as two display units.

  In the large-screen display board 1 of the present invention having the above-described configuration, the display units 5 and 6 including the reversible information display panel can be freely changed in size as desired by using a large rewriting device. it can. In each of the display units 5 and 6, it is possible to display characters on a large screen freely.

  FIG. 2 is a view showing another example of a large screen display board using the reversible information display panel of the present invention. In the example shown in FIG. 2, the display unit 5 and the display unit 6 constituting the large-screen display board 1 are not divided into two in the vertical direction as shown in FIG. A large-screen display board 1 is configured by connecting display panels 7, 8 and 9 which are equally divided in three directions. In this example, since each of the display panels 7 to 9 can be configured to be small (for example, corresponding to about A3 and A4), a small rewriting device can be used. Similarly to the example shown in FIG. 1, in each of the display panels 7 to 9, the display unit 5 and the display unit 6 can be set to two area colors.

  Hereinafter, a reversible and dry information display panel used for the above-described large screen display board will be described.

  FIGS. 3A to 3C are diagrams showing an example of the structure of the reversible information display panel used in the present invention. The reversible information display panel shown in FIG. 3A has different charging characteristics, for example, in a sealed space in which air is contained between two substrates 11 and 12 that are parallel to each other. It is configured by enclosing two types of display medium 13 of black and white (in this case, a white display medium 13W composed of particle groups and a black display medium 13B composed of particle groups are shown). In the example shown in FIG. 3B, in addition to the example shown in FIG. 3A, a partition 14 is provided between the substrates 11 and 12 in a lattice shape to form cells. Moreover, in FIG.3 (b), the partition in front is abbreviate | omitted. Further, in the example shown in FIG. 3C, the above-described display medium 13 is enclosed in a transparent capsule 17, and a plurality of capsules 17 are arranged between the substrates 11 and 12 without providing a partition, thereby displaying reversible information. The panel is configured.

  FIGS. 4A to 4C are diagrams showing other examples of the structure of the reversible information display panel of the present invention. The reversible information display panel shown in FIGS. 4A to 4C has a conductive member 15 on the inner surface side of each of the substrates 11 and 12, in addition to those described with reference to FIGS. 16 and at least the conductive member 16 on the transparent substrate 11 side is a transparent conductive member.

  In such a reversible information display panel, by applying an electric field to the display medium 13 having different charging characteristics, the display medium 13 charged at a low potential is attracted toward the direction of the high electric field by Coulomb force or the like. Then, the display medium 13 charged to a high potential is attracted toward the electric field direction of the low electric potential, and the transfer direction of the display medium 13 is changed with the change of the electric field direction, and the display medium 13 is required to the transparent substrate 11 side. Information can be displayed.

  Therefore, in the places shown in FIGS. 3A to 3C and FIGS. 4A to 4C, a two-color display medium, that is, a white display medium 13W composed of particle groups and a black display medium 13B composed of particle groups. 13 is a display medium particle that constitutes a display medium by vertically moving 13 between the two substrates according to an electric field formed by charges such as electrostatic latent images applied to the outside of the substrates 11 and 12. By making the white display medium 13 </ b> W or the black display medium 13 </ b> B visually recognized by the observer with the size of the pixel unit as a pixel unit, the display can be performed on the transparent substrate 11.

  In addition, in such a panel shown in FIGS. 3A to 3C and FIGS. 4A to 4C, the white display medium 13W made of a particle group is changed to a white display medium made of a powder fluid, and the particle group. The black display medium 13B made of can be replaced with a black display medium made of powdered fluid. In addition, the combination of colors of the two-color information display medium of the reversible information display panel is not limited to white and black as described above, but may be any combination of various realizable colors. it can.

  In the reversible information display panel as described above, a display medium 13 is sealed in a sealed space between two opposing substrates 11 and 12 that are transparent at least one of them, and an electric field is applied to the display medium 13. The display panel is a reversible display panel that displays information by moving particles and using a particle group or powdered fluid as the display medium 13 and making the display medium 13 visible through the transparent substrate 11, and so on. A wide viewing angle can be secured under a large contrast. In addition, the information (display contents) is rewritten, that is, the electric field is applied only when the display medium 13 is moved. After the movement, the display medium 13 stays at the moved position without the action of the electric field. It can be held for a long time. On the other hand, when information is to be rewritten, the display medium 13 is moved again to display another information by applying the electric field again, so that the information can be rewritten reversibly.

  Here, since the display medium 13 displays information directly, the size of the particles (display medium particles) constituting the display medium 13 determines the clearness of the information. Therefore, here, preferably, a display medium is composed of particles composed of particles for a display medium composed of particles having an average particle diameter of 3 to 10 μm, or the display medium is adjusted so that the particles for a display medium become a powder fluid. By doing so, the display of clear information is ensured and the display of delicate and precise information is enabled. In addition, since the total thickness of the display panels 2, 3, 7, 8, and 9 is very thin, being 10 μm or more and less than 1 mm, the protective sheet is attached to the protective sheet and the display panel is mounted. The display units 5 and 6 can be configured to be detachable using a mounting method such as a pocket method or a cassette method.

  Next, an example of information display, information rewriting, and information erasing in the reversible information display panel used in the present invention having the above-described configuration will be described.

  FIG. 5 is a diagram for explaining an example of information display on the reversible information display panel used in the present invention. In the reversible information display panel used in the present invention, as shown in an example in FIG. 5, the transparent substrate 11 side external surface of the reversible information display panel in which an easily movable display medium 13 is sealed between opposing substrates 11 and 12. In addition, an electrostatic field is formed by applying a charge by some charge forming means 21. According to the electrostatic field, the easily movable display medium 13 charged to the negative polarity is attracted by the Coulomb force toward the substrate portion charged to the positive polarity, and toward the substrate portion charged to the negative polarity. The easily movable display medium 13 charged to a positive polarity is attracted by Coulomb force or the like, and the easily movable display medium 13 is attracted to the inner surface of the transparent substrate 11 and electrostatically attached thereto, whereby information such as an image is displayed. Display is made.

  This electrostatic latent image is formed by transferring an electrostatic latent image formed by an ordinary electrophotographic system using an electrophotographic photosensitive member onto the reversible information display panel of the present invention, or by ion flow. It can also be performed by a method such as directly forming an electrostatic latent image. As shown in an example of FIG. 5, the easily movable display medium 13 attracted to the inner surface of the transparent substrate 11 is adhered as it is even if the electrostatic field disappears. (Memory). FIG. 5 illustrates a positively charged white display medium 13W and a negatively charged black display medium 13B.

  FIG. 6 is a diagram for explaining an example of information rewriting in the reversible information display panel used in the present invention. Once the panel on which information such as an image has been displayed is left as it is, as shown in an example in FIG. 6, the charge is applied by the new charge forming means 21 to the outer surface of the display panel on the transparent substrate 11 side. A new electrostatic field is formed. According to the newly formed electrostatic field, the easy-movable display medium 13 again moves, and the negatively-charged easily-movable display medium 13 has a Coulomb force toward the positively charged substrate portion. In addition, the easily movable display medium 13 charged to the positive polarity is attracted by the Coulomb force or the like toward the substrate portion charged to the negative polarity, and the easily movable display medium 13 becomes the transparent substrate 11. The information display such as an image is rewritten by being attracted and electrostatically attached to the inner surface. FIG. 6 illustrates a positively charged white display medium 3W and a negatively charged black display medium 3B.

  FIG. 7 is a view for explaining an example of information erasure in the reversible information display panel used in the present invention. As shown in FIG. 7, charge forming means 22 and 23 are arranged on the outer surfaces of the substrates 11 and 12 of the display panel, and an alternating voltage is applied to the substrates 11 and 12, for example. Thereby, information such as images can be erased by supplying electric charges to the outer surfaces of the substrates 11 and 12 of the reversible information display panel.

  When the information display panel having the above-described configuration is used as the display panels 2, 3, 7, 8, and 9 of the large screen display board, it is possible to make the respective substrates 11 and 12 made of a plastic material to reduce the thickness of the display panel. And it is preferable for realizing weight reduction.

  By the way, about the board | substrates 11 and 12 of an information display panel, those at least one board | substrate 11 is a transparent substrate which can confirm the color of a display medium from the outer side of a panel, and this board | substrate 11 has the high transmittance | permeability of visible light, and It is preferable to use a material having good heat resistance. The substrate 12 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic resin, flexible materials such as metal sheets, and flexibility such as glass and quartz. An inorganic sheet having no surface is mentioned.

  The thickness of the substrate is preferably 2 to 400 μm, more preferably 5 to 300 μm. If it is too thin, it will be difficult to maintain the strength and the uniformity of the distance between the substrates, and if it is thicker than 400 μm, there will be a disadvantage that the display medium will not move due to the force of an electric field such as an electrostatic latent image formed outside the substrate.

In addition, the constituent materials of the conductive members 15 and 16 provided on the substrate as necessary include metals such as aluminum, silver, nickel, copper, and gold, ITO, indium oxide, conductive tin oxide, and conductive zinc oxide. Examples thereof include conductive metal oxides such as polyaniline, polypyrrole, polythiophene, and the like, which are appropriately selected and used. As a method for forming a conductive member, the above-described materials are formed into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or a conductive agent is mixed with a solvent or a synthetic resin binder. Then, a method of coating is used.
In this case, the conductive member 16 provided on the viewing side substrate 11 needs to be transparent, but the conductive member 15 provided on the back side substrate does not need to be transparent. In any case, the above-mentioned material that can form a pattern and is conductive can be preferably used.

  The thickness of the conductive member 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 conductive member 15 provided on the back side substrate 12 are the same as those of the conductive member 16 provided on the viewing side substrate described above, but need not be transparent.

  Also, as for the partition 14 provided as necessary, the shape is appropriately set appropriately depending on the type of display medium related to the display, and thus cannot be specified unconditionally, but the width of the partition is 2 The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm. In forming the partition walls, a double rib method in which ribs are formed on each of the opposing substrates 11 and 12 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.

  The cells formed by the partition walls 14 made of these ribs are illustrated in a schematic plan view in FIG. 8 in a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the substrate plane direction. Is exemplified by a lattice shape, a honeycomb shape, or a mesh shape. It is better to make the part corresponding to the partition part visible from the display surface side (the area of the cell frame part) as small as possible, and the clearness of information display increases.

  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. Any of these methods can be suitably used for the information display panel according to the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.

  Next, display medium particles (hereinafter also referred to as particles) constituting the display medium 13 used in the information display panel will be described. The particles for the display medium can form a particle group by itself to form a display medium, form a particle group combined with other particles to form a display medium, or can be adjusted to become a powder fluid described later to be a display medium. can do. 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, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene, styrene acrylic resin Polyolefin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate, polysulfone, polyether, polyamide and the like, 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, polyamines, and imidazole derivatives.
In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

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

Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon and the like.
Examples of blue colorants include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chlorides, Fast Sky Blue, Indanthrene Blue BC, and the like.

  Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, resol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment Red 2 etc.

Examples of yellow colorants include yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment Yellow 12 etc.
Examples of green colorants include chrome green, chromium oxide, pigment green B, C.I. I. Pigment Green 7, Malachite Green Lake, Final Yellow Green G, etc.

Examples of the orange colorant include red 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.

  Moreover, it is preferable that the particles constituting the display medium 13 have a mean particle diameter d (0.5) in the range of 3 to 10 μm and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the display medium. .

Furthermore, here, 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 diameter is 50% larger than this and 50% smaller than this, and d (0.1) is the ratio of particles smaller than 10%. % Is a numerical value expressing the particle diameter in μm, and d (0.9) is a numerical value expressing the particle diameter in which 90% or less of the particles are less than this in μm.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and uniform particle movement becomes possible.

  Furthermore, regarding the correlation of each particle, the ratio of the d (0.5) of the particle having the minimum diameter to the d (0.5) of the particle having the maximum diameter among the used particles is 50 or less, preferably 10 or less. Is important.

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 the particle size distribution 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). Measurement of diameter and particle size distribution can be performed.

  Next, for example, the powder fluid used as the display medium 13 used for the information display panel will be described. For example, the applicant has obtained the right of “Electronic Powder Fluid (registered trademark): Registration Number 4636931” for the name of the powder fluid used as the display medium in the present invention.

  The “powdered fluid” here 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, a liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of a liquid and anisotropy (an optical property) that is a characteristic of a 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. Therefore, it has been found here 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 a powder fluid.

  That is, the pulverulent fluid in the present invention is an intermediate state having both particle and liquid properties, as in the definition of liquid crystal (liquid and solid intermediate phase), and the gravity characteristic that is the characteristic of the particles described above. 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. In the information display panel according to the present invention, a solid substance can be obtained as a dispersoid. To do.

  The information display panel according to the present invention comprises a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, as a display medium between opposing substrates, at least one of which is transparent. Such a powder fluid can be easily and stably moved by a Coulomb force by applying a low voltage. As described above, this powdered fluid is a substance in an intermediate state of both fluid and particle characteristics that exhibit fluidity by itself without borrowing the force of gas or liquid. The powder fluid can be in an aerosol state in particular, and in the information display panel according to the present invention, a solid substance is used in a state of being relatively stably suspended as a dispersoid in the gas.

  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 initial charge amount, the contact with the partition wall, the contact with the substrate, the charge associated with the elapsed time. It was found that depending on the attenuation, the saturation value of the charging behavior of the particles for the display medium is a dominant factor.

  In addition, when used in a dry information display panel that uses particles or powdered fluid composed of particles for display media as they are as the display medium, it is important to manage the gas in the void surrounding the display medium between the panel substrates. Contributes to the improvement of stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, and more preferably 35% RH or less. When used in a dry information display panel in which a particle group composed of particles or powdered fluid is enclosed in a capsule and used as a display medium, the management of the gas in the void surrounding the display medium between the panel substrates is not so important. .

  3A to 3C and FIGS. 4A to 4C, the gaps are defined by the conductive members 15 and 16 (the conductive members from the portions sandwiched between the opposing substrates 11 and 12). In this case, the gas portion in contact with the so-called display medium 13 excluding the occupied portion of the display medium 13, the occupied portion of the partition wall 14 (when the partition wall is provided), and the seal portion of the information display panel.

  The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in the information display panel so that the humidity is maintained. For example, filling of the display medium, assembly of the information display panel, etc. are performed in a predetermined humidity environment. It is important to apply a sealing material and a sealing method that prevent moisture from entering.

  The distance between the substrate 11 and the substrate 12 in the information display panel here may be adjusted to 10 to 100 μm, preferably 10 to 50 μm, as long as the display medium 13 can be moved and the contrast can be maintained. The volume occupation ratio of the display medium 13 in the space between the opposing substrates is preferably 5 to 70%, and more preferably 5 to 60%. When it exceeds 70%, the movement of the display medium 13 is hindered, and when it is less than 5%, the contrast tends to be unclear.

  The large-screen display board using the reversible information display panel according to the present invention can display the new information any number of times after the displayed information is securely erased. Display is unnecessary, and the cost and work man-hours for the display can be greatly reduced, and at the same time, it can be suitably used for applications that sufficiently prevent resource consumption.

It is a top view which shows an example of embodiment of the big screen display board which concerns on this invention. It is a top view which shows the other example of embodiment of the big screen display board which concerns on this invention. (A)-(c) is a figure which shows an example of the structure in the reversible information display panel used by this invention, respectively. (A)-(c) is a figure which shows the other example of the structure in the reversible information display panel of this invention, respectively. It is a figure for demonstrating an example of the information display in the reversible information display panel used by this invention. It is a figure for demonstrating an example of the information rewriting in the reversible information display panel used by this invention. It is a figure for demonstrating an example of the information deletion in the reversible information display panel used by this invention. It is an approximate line top view showing the example of arrangement of the cell divided by the partition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Large screen display board 2, 3, 7, 8, 9 Information display panel 4 Display board main body 5, 6 Display part 11, 12 Board | substrate 13 Display medium (particle group or powder fluid)
13W White display medium 13B Black display medium 14 Partitions 15, 16 Conductive member 17 Capsule 21, 22, 23 Charge forming means

Claims (4)

  A display medium is enclosed in a sealed space between two substrates facing each other and at least one of which is transparent, and the display medium is moved by an electric field generated by an electric charge formed on the surface of the substrate. A large-screen display board having a reversible and dry-type information display panel as a display unit that displays necessary information on the side, (1) using two types of display media having different colors and charging characteristics; 2) The reversible information display characterized in that the average particle diameter of the display medium particles used in the information display panel is in the range of 3 to 10 μm, and (3) the total thickness of the information display panel is 10 μm or more and less than 1 mm. Large screen display board using a panel.   The thickness between at least one of the two substrates is 0.4 mm or less, and the distance between the substrates formed by the two substrates facing each other is 0.1 mm or less. A large screen display board using the reversible information display panel described in 1.   A large screen display board using the reversible information display panel according to claim 1 or 2, wherein each substrate is made of a plastic material.   The large screen display board using the reversible information display panel according to any one of claims 1 to 3, wherein a particle group or a powder fluid is used as a display medium.

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