JP4855737B2 - Manufacturing method of information display panel - Google Patents

Description

  In the present invention, a display medium of two colors having different charging characteristics is enclosed in a cell formed by a partition between two substrates, at least one of which is transparent, and display is performed from electrodes provided on each of the two substrates. The present invention relates to a method for manufacturing an information display panel that displays information such as an image by moving a display medium by applying an electric field to the medium, and an information display panel.

  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, particles with high specific gravity, such as titanium oxide, are dispersed in a solution with low specific gravity, so it is easy to settle, and it is difficult to maintain the stability of the dispersed state. Have the problem of lacking. 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, since the structure is complicated because the charge transport layer and the charge generation layer are arranged, it is difficult to uniformly inject the charge into the conductive particles, so that there is a problem that the rewrite stability of display information is lacking. .

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 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 information display panel having the above-described configuration, it is necessary to fill a cell formed of the partition formed on one substrate with two colors, for example, white and black display media having different charging characteristics. Conventionally, to fill a two-color display medium, the first color display medium is sprayed from above and filled into the cell, and then the second color display medium is sprayed from above to fill the cell. As described above, the display medium of the first color and the display medium of the second color are separately filled in order.

  After that, a display medium removal process for removing the display medium remaining on the partition wall with a roller or the like was performed. In this removal process, the display medium filled later is not only the display medium remaining on the partition wall. Since the display medium filled in the cell is likely to be partially removed, it is difficult to control the filling ratio of the first color display medium and the second color display medium, for example, the black and white filling ratio. . Thus, for example, if the filling ratio of the black and white display medium in the cell is different, there is a problem that correct contrast cannot be displayed and display quality is deteriorated.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, to correctly control the filling ratio of two color display media, and to provide an information display panel manufacturing method and information display capable of obtaining good display quality. Try to provide a panel.

  According to a first aspect of the present invention, there is provided a method for manufacturing an information display panel comprising: a two-color display medium having opposite charging polarities in a cell formed by a partition between two substrates, at least one of which is transparent. An information display panel manufacturing method for displaying information such as an image by moving a display medium by enclosing and applying an electric field to the display medium from an electrode provided on each of two substrates. To fill a cell with a two-color display medium having opposite polarities, the two-divided electrode is placed on a substrate provided with a partition wall for forming the cell, and first the first color display medium is to be filled. The divided electrode on the side having the area corresponding to the ratio is filled with a potential having a polarity opposite to the charged polarity of the display medium of the first color, and then the display medium of the second color is filled. The other with the area corresponding to the ratio you want to fill After filling the split electrode with a potential opposite to the charged polarity of the display medium of the second color applied to the split electrode and filling the cell with a predetermined amount of two colors of display medium having opposite charging polarities. The divided electrodes are made to conduct so as to have the same potential outside the display area.

  In addition, in the method for manufacturing an information display panel according to the second aspect of the present invention, a two-color display in which charging polarities are opposite to each other in a cell formed by a partition between two substrates, at least one of which is transparent. An information display panel manufacturing method for displaying information such as an image by moving a display medium by enclosing the medium and applying an electric field to the display medium from electrodes provided on each of two substrates, In filling a cell with a two-color display medium having opposite charging polarities, a two-divided electrode is arranged on a substrate provided with a partition that forms the cell. Filling with the divided electrode on the side having the area corresponding to the ratio to be filled at the ground potential and the other electrode side of the divided electrode at the floating potential, and then displaying the second color Fill the medium to the desired ratio The divided electrode potential having the corresponding area is filled while being switched from the floating potential to the ground potential and the other electrode side of the divided electrode is switched from the ground potential to the floating potential. It is characterized in that after a fixed amount of two-color display media having opposite charging polarities are filled in a cell, the divided electrodes are made to conduct so as to have the same potential outside the display area. In the second invention of the present invention, the “floating potential” assumes a floating potential state where no positive potential is applied.

  As a preferred example of the method for manufacturing the information display panel of the present invention, a predetermined amount of two-color display media having oppositely charged polarities are filled in a cell, and then the other substrate is bonded to display information. When the panel is configured, the divided electrodes may be electrically connected outside the display area.

  In the information display panel of the present invention, a display medium of two colors having opposite charging polarities is enclosed in a cell formed by a partition wall between two substrates, at least one of which is transparent. An information display panel for displaying information such as an image by moving the display medium by applying an electric field to the display medium from the electrodes provided on each of the electrodes, and the electrode provided on at least one of the two substrates, The display area is divided into two parts and is electrically connected so as to have the same potential outside the display area.

  As a preferred example of the information display panel of the present invention, the division ratio of the electrodes divided into two in the display area is the enclosure ratio of the two-color display medium enclosed in the cell and having opposite charging polarities. The electrode divided into two in the display area is arranged in the cell in synchronization with each cell in the division ratio, and includes the divided electrode provided on at least one substrate. The electrodes provided on the two substrates are all line electrodes, the electrodes provided on the two substrates are arranged orthogonally to each other, and a combination of two-color display media having opposite charging polarities. Is a combination of a white display medium and a black display medium, and the arrangement of the electrodes and the arrangement of the partition walls forming the cell may be configured so that the electrode portion in the cell is divided into two. .

  In the present invention, in filling a cell with two-color display media having opposite charging polarities, a two-divided electrode is disposed on a substrate provided with a partition for forming a cell. (1) First, first The display medium of the color is filled in a state in which a potential opposite to the charged polarity of the display medium of the first color is applied to the divided electrode having the area corresponding to the ratio to be filled, The second color display medium is filled in a state in which a potential opposite to the charged polarity of the second color display medium is applied to the other divided electrode having an area corresponding to the ratio to be filled, After filling a cell with a predetermined amount of two-color display media having oppositely charged polarities in the cell, the divided electrodes are made conductive so as to have the same potential outside the display region, or (2) First, Color display medium on the side having the area corresponding to the ratio to be filled Fill the split electrode with the ground potential and the other electrode side of the split electrode with the floating potential, and then fill the display medium of the second color with the area corresponding to the ratio to be filled. The divided electrode potential of the divided electrode is charged while being switched from the floating potential to the ground potential, and the other electrode side of the divided electrode is charged while being switched from the ground potential to the floating potential. After filling the cell with two colors of display media with opposite polarities, the positively charged particles move according to the electric field from high potential to low potential by conducting the divided electrodes so that they have the same potential outside the display area. The negatively charged particles move according to the electric field from the low potential to the high potential, and the filling ratio of the two-color display medium can be controlled correctly, resulting in good display quality. It is possible to manufacture the information display panel capable of Rukoto.

  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 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 or Coulomb force, etc., and the display medium changes the moving direction by changing the electric field direction by switching the potential, thereby displaying information such as an image. Is made. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain the rewrite stability of display information or the continuous display stability of display information. Here, as the force applied to the particles constituting the display medium, in addition to the force attracted by the Coulomb force between the particles, an electric image force with the electrode, 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 FIG.

  In the example shown in FIG. 1, at least two types of display media 3 (here, white display particles composed of particles 3Wa for white display media) having different optical reflectance and charging characteristics composed of at least one type of particles. The black display medium 3B including a particle group of the medium 3W and the black display medium particles 3Ba) is generated by applying a voltage between the electrode 5 provided on the substrate 1 and the electrode 6 provided on the substrate 2. Depending on the electric field, the substrate is moved perpendicularly to the substrates 1 and 2 and the black display medium 3B is visually recognized by the observer to display black, or the white display medium 3W is visually recognized by the observer and white display is performed. Is going. In the example shown in FIG. 1, a partition wall 4 is formed between the substrates 1 and 2, and a plurality of square cells are provided in a lattice shape (the partition wall in front of the drawing is omitted). In this example, the electrode 5 is divided into two divided electrodes 5-1 and 5-2 in order to perform the filling of the display medium 3 described in detail below. 5-1 and the divided electrode 5-2 are electrically connected to each other at a position outside the display area by some means, and the electrode 5 is integrally formed.

  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 present invention is characterized in that, in an information display panel using the display medium having the above-described configuration, at least two colors are displayed in a cell composed of a partition wall 4 formed on a substrate 1 on the side where at least divided electrodes are provided. In the method of filling the medium 3.

  FIG. 2 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. 2, the electrode 5 formed in the column direction corresponding to the cell 11 formed by the partition wall 4 on the substrate 1 is divided into two, and one is used for filling the white display medium 3W. The electrode 5-1 is used, and the other electrode is a divided electrode 5-2 used for filling the black display medium 3B. In this example, the four divided electrodes 5-1 are connected to each other through the wiring portions 12 arranged on the substrate 1 and the wiring portions 13 arranged with four divided electrodes 5-2 on the substrate 1 are provided. Connected through. Note that the end of the wiring portion 13 on the substrate 1 is a signal input end 14.

  In this example, it is preferable to arrange an insulating material between the divided electrode 5-1 and the divided electrode 5-2. As a material of this insulating material, tantalum pentoxide or silicon nitride is preferably used, but any other material can be used as long as the insulating property can be sufficiently secured. Moreover, it is preferable that the space | interval of the division | segmentation electrode 5-1 and the division | segmentation electrode 5-2 is the range of 5-100 micrometers. However, even if an insulating material is not disposed, there is no problem as long as a sufficient interval between the divided electrodes 5-1 and 5-2 can be secured. The divided electrodes 5-1 and 5-2 are electrically connected and conducted at a position outside the display area of the information display panel in the process of assembling as a panel.

  A method of filling the cell 11 on the substrate 1 having the above-described structure with two colors, here, the white display medium 3W and the black display medium 3B will be described with reference to FIGS. .

  In the first invention of the manufacturing method of the present invention, first, as shown in FIG. 3A, the white medium 3W is applied to the divided electrode 5-1 on the side having an area corresponding to the ratio to be filled. In this state, a white display medium 3W is sprayed from above and filled in the cell 11 in a state in which a potential having a polarity opposite to the charged polarity is applied. Thereby, as shown in FIG.3 (b), only the part of the division | segmentation electrode 5-1 can be filled with the white display medium 3W. Next, as shown in FIG. 3C, the black display medium 3B has a polarity opposite to the charged polarity of the black display medium 3B in the other divided electrode 5-2 having an area corresponding to the ratio to be filled. In this state, the black display medium 3 </ b> B is sprayed from above and filled in the cell 11. As a result, as shown in FIG. 3D, a predetermined amount of two-color display medium having opposite charging polarities can be filled in the cell.

  In the second invention of the manufacturing method of the present invention, first, the white display medium 3W is grounded to the divided electrode 5-1 on the side having the area corresponding to the ratio to be filled, as shown in FIG. In this state, the other divided electrode 5-2 side is set to a floating potential. In this state, the white display medium 3W is sprayed from above and filled in the cell 11. Thereby, as shown in FIG.3 (b), only the part of the division | segmentation electrode 5-1 can be filled with the white display medium 3W. Next, as shown in FIG. 3C, the black display medium 3B was applied by switching the potential of the divided electrode 5-2 having the area corresponding to the ratio to be filled from the floating potential to the ground potential. In this state, the other divided electrode 5-2 side is switched from the ground potential to the floating potential, and in this state, the black display medium 3B is sprayed from above to fill the cell 11. As a result, as shown in FIG. 3D, a predetermined amount of two-color display medium having opposite charging polarities can be filled in the cell.

  By doing so, as shown in the upper right of FIG. 2, the display medium filling state of one cell 11 is filled with the white display medium 3W only on the divided electrode 5-1, and only on the divided electrode 5-2. The display medium 3B is filled. Therefore, each of the white display medium 3W and the black display medium 3B is present at the bottom of the cell 11 after filling, and when the display medium remaining on the partition wall is removed with a roller or the like as in the conventional case, the white display medium 3W and Since both the black display medium 3B are removed, accurate control of the black and white filling ratio can be easily performed.

  When the display medium 3 is filled in the cell 11 and the other substrate 2 is bonded to form an information display panel for display, the divided electrode 5-1 and the divided electrode 5 divided into two in the cell 11 are displayed. -2 (insulated between the two) must be applied with the same voltage. Therefore, in the example shown in FIG. 2, the divided electrodes 5-1 and 5-2 are electrically connected outside the display area. Specifically, a wiring portion 15 connected to the divided electrode 5-2 is further arranged at a position on the opposite side of the wiring portion 13 of the divided electrode 5-2 from the wiring portion 12 of the divided electrode 5-1. The other substrate 2 is provided with an electrode (not shown here) in which the wiring portion 12 and the wiring portion 15 are arranged to be connectable for each cell 11. Then, by using the electrode on the substrate 2, the sealing agent 16 used when bonding the substrates 1 and 2 is ACS (anisotropic conductive seal), or using a conductive paste or the like, the wiring portion 12 and the wiring portion 15 are connected. It is configured so that it can be electrically connected. With this configuration, the same driving voltage can be applied to the divided electrode 5-1 and the divided electrode 5-2 by applying the driving voltage to the signal input terminal 14.

  FIG. 4 is a diagram for explaining an example of an electrode pattern on the substrate on the side filled with the display medium. In the example shown in FIG. 4, the divided electrodes 5-1 and the divided electrodes 5-2 are alternately arranged in the column direction on the panel display portion 22 of the four information display panels on the mother glass substrate 21. Is arranged. All the divided electrodes 5-1 and the divided electrodes 5-2 in the mother glass substrate 21 are respectively connected to the white display medium filling electrode 23 and the black display medium filling electrode 24 provided at the corner of the mother glass substrate 21. It is connected. At this stage, the divided electrode 5-1 and the divided electrode 5-2 are electrically insulated from each other.

  As described above, the divided electrode 5-1 and the divided electrode 5-2 are arranged on the mother glass substrate 21, and the panel 11 is provided with the predetermined partition walls 4 to form the cells 11, so that white display is performed. The medium 3W and the black display medium 3B are filled in the cell 11 in order. The order of filling is not particularly limited. As an example, when the black display medium 3B is filled, a voltage having a ground potential is applied to the black display medium filling electrode 24, and a voltage having a floating potential is applied to the white display medium filling electrode 23. When the white display medium 3W is filled, the white display medium filling electrode 23 is switched from the floating potential to the ground potential to apply a voltage having the ground potential, and the black display medium filling electrode 24 is switched from the ground potential to the floating potential to float. A voltage having a potential is applied. Further, instead of applying a voltage having a ground potential and a floating potential, it is also possible to apply voltages that give two different polar potentials. For example, when filling the black display medium 3 </ b> B and the white display medium 3 </ b> W, a voltage of 1 kv is applied to the black display medium filling electrode 24 and a voltage of −1 kv is applied to the white display medium filling electrode 23.

  FIG. 5 is a diagram for explaining an example of a completed state of the information display panel alone. In the example shown in FIG. 5, one pixel corresponds to one cell. In this example, two electrodes, that is, a divided electrode 5-1 and a divided electrode 5-2, are provided in the cells 11 arranged in the column direction, and a white display medium 3W and a black display medium are provided in each cell 11. 3B. The divided electrode 5-1 and the divided electrode 5-2 are electrically connected to the electrode 32 on the other substrate 2 via a conductive particle 31 in the sealant 16 at a position outside the display area of the panel. . When a voltage is applied so as to give a potential difference between the display surface side electrode and the back side electrode of the panel shown in FIG. 5 and an electric field is applied to the enclosed display medium, and the switching of the electric field direction is repeated, the white display medium 3W And the black display medium 3B move in the opposite direction to the electric field direction, so that white display and black display are possible.

  In the example described above, the pixels and the cells formed from the grid-like partition walls are made to correspond to 1: 1 for the sake of simplicity, and the number of cells is small, for example, 4 × 2 8 in the example of FIG. For example, the ratio of the pixel to the cell is changed in a synchronized manner such as 4: 1, the example in which the pixel and the cell are not synchronized by, for example, a honeycomb-shaped partition wall, and the example in which the number of pixels is large, Needless to say, the present invention can be suitably applied. Moreover, although the example which formed the electrode 5 and the partition 4 on the board | substrate 1 was demonstrated in the example mentioned above, this invention is applicable also to the electrode 6 on the board | substrate 2 similarly. Furthermore, although the example which used the white display medium and the black display medium as a two-color display medium was demonstrated, it is not limited to the combination of this color.

  In the example described above, the line-shaped divided electrodes 5-1 and 5-2 and the partition walls 4 are provided in synchronization. However, as shown in FIG. 6A, the lattice-shaped partition walls 4 are staggered. As shown in FIG. 6B and the example of the honeycomb-shaped partition walls 4 as shown in FIG. 6B, the line-shaped divided electrodes 5-1 and the divided electrodes 5-2 and the partition walls 4 are made asynchronous. You can also. Furthermore, in the above-described example, the division ratio between the line-shaped divided electrode 5-1 and the divided electrode 5-2 is 1: 1, but the division ratio is 1: 2 or 1 as shown in FIG. : 1.5 can also be used. In this case, the amount of two-color display medium corresponding to the division ratio can be filled and sealed in the cell. Furthermore, although the line-shaped electrode is used in the above-described example, as shown in FIGS. 6D and 6E, the divided electrode 5-1 divided into two in the cell 11 formed by the partition 4 and the divided electrode are used. Electrodes 5-2 (regardless of shape, size, and division ratio) are arranged at intervals so as to be insulated from each other when the display medium is filled, and function as one electrode 5 by being electrically connected to each other after the panel is formed. It can also be comprised.

  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 include metals such as aluminum, silver, nickel, copper, and gold, conductive metal oxides such as ITO, indium oxide, conductive tin oxide, and conductive zinc oxide, and conductive materials such as polyaniline, polypyrrole, and polythiophene. Ionic polymers 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 is optimally set as appropriate 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, but the width of the partition walls is 2 to 100 μm, preferably The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm, to 3 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. 7, the cells formed by the partition walls made of these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the substrate plane direction. 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 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 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, resol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment Red 2 etc.

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

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

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

  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, 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 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 powdered 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, preferably 50% RH or less, more preferably 35% RH or less with respect to the humidity of the gas in the gap.
In FIG. 1, this void portion refers to electrodes 5 and 6 (when electrodes are provided inside the substrate), a portion occupied by the display medium 3, and a space occupied by the partition 4 from the portion sandwiched between the opposing substrate 1 and substrate 2. The gas part which a so-called display medium touches excluding the part and the seal part of the information display panel shall be pointed out.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in an information display panel so that the humidity is maintained, for example, filling a display medium, assembling an information display panel, etc. in a predetermined humidity environment, It is important to apply a sealing material and a sealing method that prevent moisture from entering from the outside.

The distance between the substrates in the information display panel that is the subject of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the display medium in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. 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.

It is a figure which shows an example of the information display panel used as the object of this invention. It is a figure for demonstrating an example of the manufacturing method of the information display panel of this invention. (A)-(d) is a figure for demonstrating an example of the filling process of the display medium in the manufacturing method of the information display panel of this invention, respectively. It is a figure for demonstrating an example of the electrode pattern in the board | substrate of the side filled with a display medium. It is a figure for demonstrating an example of the completed state of the information display panel single-piece | unit. (A)-(e) is a figure for demonstrating an example of the relationship between an electrode and a partition, 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 this invention.

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 Partition 5, 6, 32 electrode 5-1, 5-2 Divided electrode 11 Cell 12, 13, 15 Wiring part 14 Signal input terminal 16 Sealant 21 Mother Glass Substrate 22 Panel Display Unit 23 White Display Medium Filling Electrode 24 Black Display Medium Filling Electrode 31 Conductive Particles

Claims (3)

  A display medium of two colors having opposite charging polarities is enclosed in a cell formed by a partition wall between two substrates, at least one of which is transparent, and an electrode provided on each of the two substrates is used as a display medium. An information display panel manufacturing method for displaying information such as an image by moving a display medium by applying an electric field, and filling a cell with a display medium of two colors having opposite charging polarities. First, a two-divided electrode is arranged on a substrate provided with a partition wall that forms a cell. First, a first color display medium is placed on a divided electrode on the side having an area corresponding to the ratio to be filled. The display medium is filled in a state where a potential opposite to the charged polarity of the display medium is applied, and the second color display medium is then applied to the other divided electrode having an area corresponding to the ratio to be filled. The polarity opposite to the charge polarity of the color display medium After filling the cell with a predetermined amount of two-color display media having opposite charging polarities, the divided electrodes are made to be electrically connected to the same potential outside the display area. A method of manufacturing a characteristic information display panel.   A display medium of two colors having opposite charging polarities is enclosed in a cell formed by a partition wall between two substrates, at least one of which is transparent, and an electrode provided on each of the two substrates is used as a display medium. An information display panel manufacturing method for displaying information such as an image by moving a display medium by applying an electric field, and filling a cell with a display medium of two colors having opposite charging polarities. The two-divided electrode is arranged on the substrate provided with the partition walls for forming the cells, and first, the divided electrode on the side having the area corresponding to the ratio to be filled with the first color display medium is set to the ground potential. In addition, the other electrode side of the divided electrode is filled with a floating potential, and then the divided electrode potential of the second color display medium having an area corresponding to the ratio to be filled is floated. Potential? A two-color display medium in which a predetermined amount of the charging polarity is reversed while being charged while being switched to the ground potential and filling the other electrode side of the divided electrode from the ground potential to the floating potential. After the cell is filled in the cell, the divided electrode is made conductive to have the same potential outside the display region. When a predetermined amount of two-color display media having opposite charging polarities are filled in a cell and then the other substrate is bonded to form an information display panel, the divided electrodes are electrically connected outside the display area. The method for producing an information display panel according to claim 1 or 2.

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