JP2009069405A - Panel for information display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel for information display wherein voltage applied to the entire surface of the panel for information display of a dot matrix display system especially having a size A4 or larger is made constant and uniform image quality is obtained. <P>SOLUTION: The panel for information display has a rectangular dot matrix type display region wherein a display medium including charged particles which can be driven by an electric field is encapsulated between substrates and information display such as an image can be rewritten by applying an electric field from pair electrodes formed by crossing opposed line electrodes provided on the substrates to move the display medium, wherein the line electrodes having thickness t1 are provided on the rear surface side substrate, in a direction parallel to a long side of the display region and the line electrodes having thickness t2 are provided on the display surface side substrate, in a direction parallel to a short side of the display region, and 0.05 μm≤t2≤10 μm and an aspect ratio of the display region ≤t1/t2 are satisfied. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention encapsulates a display medium including charged particles that can be driven by an electric field between substrates, and applies the electric field from a counter electrode formed by crossing opposing line electrodes provided on the substrate. The present invention relates to an information display panel having a rectangular dot matrix type display area in which information display such as an image can be rewritten by being moved.
The present invention particularly relates to an information display panel having a display area having a screen size corresponding to A4, A3, B4, and B3 sizes.

  An information display device using a charged particle electric field drive method has been proposed as an information display device to which an inexpensive passive drive method instead of an active drive liquid crystal display device (LCD) can be applied.

In particular, as a passive drive type information display device having a simple structure, at least one or more types of display media configured to include charged particles having optical reflectivity and chargeability in a space between two opposing substrates are provided. 2. Description of the Related Art An information display panel using a method of displaying information such as an image by moving the display medium by enclosing and applying an electric field to the display medium is known (for example, Patent Document 1).
In the information display panel described above, line drive orthogonal to each other is provided on each of the two substrates for passive driving.
International Publication No. 2003/050606 Pamphlet

The counter electrode used in the passive matrix driving system described above is arranged so that the line electrodes are opposed and orthogonal to each other, but the voltage applied between the counter electrodes formed on the input side connection portion side for the line electrodes. And the voltage applied between the counter electrodes formed on the electrode tip side cause a difference due to electric resistance, and as a result, there is a difference in the electric field formed between the counter electrodes arranged in a dot matrix shape. This has affected the drivability of the display medium. That is, there is a problem that the image quality (for example, contrast) displayed on the display area of the information display panel is non-uniform due to the difference in driveability of the display medium.
The image quality degradation considered to be caused by the applied voltage difference due to electrical resistance is A4, A3, B4, where the length of the line-shaped electrode becomes longer among the screen sizes of A size (A7 to A3) and B size (B7 to B3). This is particularly a problem with information display panels having a display area with a screen size corresponding to the B3 size.
In the conventional information display panel, when a transparent line electrode such as ITO is used as the counter electrode, the same electrode thickness is used.

  Accordingly, an object of the present invention is to maintain uniform image quality even in the above-described conventional passive drive type information display panel, particularly in an information display panel having a display area of A4 size or larger.

  The information display panel of the present invention encloses a display medium including charged particles that can be driven by an electric field between substrates, and applies an electric field from a counter electrode formed by crossing opposing line electrodes provided on the substrate. In the information display panel having a rectangular dot matrix type display area in which information display such as an image can be rewritten by moving the display medium, the thickness t1 is parallel to the long side of the display area on the back side substrate. A transparent line electrode having a thickness t2 in a direction parallel to the short side of the display area on the display surface side substrate, 0.05 μm ≦ t2 ≦ 10 μm, and the aspect ratio of the display area The configuration is such that ≦ t1 / t2.

  The aspect ratio of the display area is X / Y where X is the long side and Y is the short side of the rectangular display area.

  In the information display panel of the present invention, it is preferable that the line electrode provided on the back side substrate and the line electrode provided on the display side substrate are formed of the same material.

  In the information display panel of the present invention, it is preferable that the thickness t1 of the line electrode provided on the back substrate is 0.05 μm ≦ t1 ≦ 20 μm.

  In the information display panel of the present invention, if the width of the line electrode provided on the back substrate is W1, and the width of the line electrode provided on the display substrate is W2, 50 μm ≦ W1, W2 ≦ 1000 μm and 1 ≦ W2 / It is preferable to configure so that W1 ≦ 1.41.

  In the information display panel of the present invention, the line electrode includes indium tin oxide (ITO), indium oxide, zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), antimony tin oxide (ATO), It is preferably formed from any one of conductive metal oxides such as conductive tin oxide and conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene.

  According to the present invention, a display medium including charged particles that can be driven by an electric field is sealed between the substrates, and an electric field is applied from the counter electrode formed by the opposing line electrodes provided on the substrate intersecting. In an information display panel having a rectangular dot matrix type display area in which information display such as an image can be rewritten by moving a medium, a line having a thickness t1 in a direction parallel to the long side of the display area on the back side substrate An electrode is provided, and a line electrode having a thickness t2 is provided on the display surface side substrate in a direction parallel to the short side of the display region so that 0.05 μm ≦ t2 ≦ 10 μm and the aspect ratio of the display region is equal to or less than t1 / t2. With this configuration, it is possible to provide an information display panel in which the voltage applied across the entire surface of an information display panel of A4 size or more is constant and the image quality is uniform. it can.

  First, the basic configuration of the information display panel of the present invention will be described. The information display panel according to the present invention is formed by line electrodes that face and cross a display medium that includes charged particles having optical reflectivity and chargeability sealed in a space between two opposing substrates. An electric field is applied from the counter electrode. Along with the applied electric field direction, the display medium is attracted by an electric field force or a Coulomb force, and the display medium is moved by a change in the electric field direction, whereby information such as an image is displayed. Therefore, it is necessary to design the display panel so that the display medium can move uniformly and maintain stability when rewriting the display repeatedly or when displaying the display information continuously. Here, the force applied to the particles constituting the display medium can be considered to be the electric mirror image force between the electrode, the substrate and the partition, the intermolecular force, the liquid bridging force, gravity, etc. in addition to the force attracted by the Coulomb force between the particles. It is done.

  An example of the information display panel of the present invention will be described with reference to FIGS. 1 (a) and (b) to FIG. In either case, a line electrode is formed on two opposing substrates, and an electric field is generated between the counter electrodes configured so as to be opposed to and orthogonal to each other to drive a display medium disposed between the substrates. This is a dot matrix type information display panel in which a portion where line electrodes are orthogonally overlapped is a display unit (1 pixel: 1 dot).

  In the example shown in FIGS. 1A and 1B, display media having at least one kind of particles including charged particles having optical reflectivity and chargeability and having different optical reflectivity and charging characteristics from each other. At least two types (here, a white display medium 3W including a group of white charged particles 3Wa and a black display medium 3B including a group of black charged particles 3Ba are shown) between the substrates. The electric field generated by applying a voltage between the electrode 5 (line electrode) provided on the substrate 1 and the electrode 6 (line electrode) provided on the substrate 2 in each cell formed by the partition walls 4. Accordingly, the substrate is moved perpendicularly to the substrates 1 and 2. Then, as shown in FIG. 1A, the white display medium 3W is visually recognized by the observer and white dot display is performed, or as shown in FIG. 1B, the black display medium 3B is visually recognized by the observer. Black dots are displayed. In addition, in FIG. 1 (a), (b), the partition in front is abbreviate | omitted. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate.

  In the example shown in FIGS. 2A and 2B, the basic configuration is the same as the example shown in FIG. 1, and three cells (each cell becomes a unit pixel. In this case, one display unit (three color unit pixels) 1 pixel: 1 dot)), an example of color display constituting a display unit is shown. In the example shown in FIGS. 2A and 2B, all the cells 21-1 to 21-3 as the display medium are filled with the white display medium 3W and the black display medium 3B, and the first cell 21-1. A red color filter 22R is provided on the viewer side, a green color filter 22G is provided on the viewer side of the second cell 21-2, a blue color filter 22BL is provided on the viewer side of the third cell 21-3, A display unit (one pixel: one dot) is composed of three cells, the first cell 21-1, the second cell 21-2, and the third cell 21-3. In this example, as shown in FIG. 2A, the white dot display is performed by moving the white display medium 3W in all the first cells 21-1 to 21-3 to the viewer side. As shown in FIG. 2B, black dots are displayed by moving the black display medium 3B in all the first cells 21-1 to 21-3 on the viewer side. Yes. Multi-color dot display can be performed by moving the display medium of each cell. In addition, in FIG. 2 (a), (b), the partition in front is abbreviate | omitted.

  In the example shown in FIG. 3, the basic configuration is the same as the example shown in FIG. 1, and three cells (each cell is a unit pixel. In this case, one display unit (one pixel: one dot) with three color unit pixels). ) Shows an example of color display constituting a display unit. In the example shown in FIG. 3, instead of using the color filter of FIG. 2, each color display is configured so that the display medium enclosed in each cell includes red charged particles 3Ra, blue charged particles 3BLa, and green charged particles 3Ga. The medium and a white display medium including white charged particles 3Wa are used. In this example, as shown in FIG. 3, red dot display is performed by moving a red display medium and a white display medium to the viewer side. Multi-color dot display can be performed by moving the display medium of each cell. In FIG. 3, the front partition is omitted.

  In the example shown in FIG. 4, the basic configuration is the same as the example shown in FIG. 3, and three cells (each cell is a unit pixel. In this case, one display unit (one pixel: one dot) with three color unit pixels). ) Shows an example of color display constituting a display unit. In the example shown in FIG. 4, magenta charged particles 3Ma, yellow charged particles 3Ya, and cyan charged particles 3Ca are used instead of the red charged particles 3Ra, blue charged particles 3BLa, and green charged particles 3Ga in FIG. Each color display medium including each of the three colors and a white display medium including the white charged particles 3Wa are sealed in a cell. In this example, as shown in FIG. 4, magenta dot display is performed by moving a magenta color display medium and a white color display medium to the viewer side. Multi-color dot display can be performed by moving the display medium of each cell. In FIG. 4, the front partition is omitted.

  In the example shown in FIGS. 5A and 5B, a black display medium configured to include black charged particles 3Ba is provided in each cell formed by the partition walls 4 in an electrode 5 (transparent line electrode) provided on the substrate 1. ) And the electrode 6 (transparent line electrode) provided on the substrate 2, the substrate is moved in a direction perpendicular to the substrates 1 and 2 in accordance with an electric field generated by applying a voltage. Then, as shown in FIG. 5A, the color of the white plate 7W is visually recognized by the observer to display white dots, or as shown in FIG. 5B, the black display medium is visually recognized by the observer. Black dots are displayed. In addition, in the example shown to Fig.5 (a), (b), the partition in front is abbreviate | omitted. Here, the same display can be performed when the black charged particles 3Ba are white charged particles and the white plate 7W is a black plate. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate.

  In the example shown in FIGS. 6A and 6B, a white display medium that includes white charged particles 3Wa in three cells in which a color plate (for example, an RGB color plate) is provided on the substrate 1 is used as the substrate 1. In the cell provided with the white plate 7W, a black display medium including black charged particles 3Ba is enclosed, and these four cells form one display unit (one pixel: one dot). As shown in FIG. 6A, a black display medium and a three-color plate (red plate 7R, green plate 7G, blue plate 7BL) are visually recognized by an observer, or black dot display is performed, or FIG. As shown in FIG. 2, the white plate 7W and the white display medium are visually recognized by the observer to perform white dot display. Multi-color dot display can be performed by moving the display medium of each cell. In addition, in the example shown to Fig.6 (a), (b), the partition in front is abbreviate | omitted. The electrode may be provided outside the substrate or may be provided so as to be embedded inside the substrate.

  In the example shown in FIG. 7, as in the example shown in FIGS. 1A and 1B, another example in which monochrome dot display is performed using the line electrodes 5 and 6 is described. In the example shown in FIG. 7, instead of the cells formed of the partition walls 4 filled with the white charged particles 3Wa and the black charged particles 3Ba shown in FIGS. 1A and 1B, the white charged particles 3Wa and the black charged particles are used. A microcapsule 9 in which a display medium made of 3Ba is filled together with an insulating liquid 8 is used.

  Hereinafter, the information display panel of the present invention will be described in more detail with reference to the drawings.

FIGS. 8A to 8C are arrangement examples of line electrodes in the information display panel of the present invention.
In FIG. 8A, the line electrode 5 is arranged on the back side substrate 1 in a direction parallel to the long side of the back side substrate 1. There is a lead line portion 10 extending from the line electrode 5 outside the display area. The lead line portion 10 is connected to a drive device power circuit on the input side. The lead wire portion 10 is formed of a metal material having a small electric resistance. A connection portion with the lead wire portion 10 which is one end portion of the line electrode 5 is a line electrode connection portion 5C, and the other end portion is a line electrode tip portion 5E. The width of the line electrode 5 is W1.
In FIG. 8B, the line electrode 6 is arranged on the display surface side substrate 2 in a direction parallel to the short side of the display surface side substrate 2. There is a lead line portion 10 extending from the line electrode 6 outside the display area. As in FIG. 8A, the lead line portion 10 is connected to the drive device power supply circuit on the input side, and the lead line portion 10 is formed of a metal material having a small electric resistance. A connection portion with the lead wire portion 10 which is one end portion of the line electrode 6 is a line electrode connection portion 6C, and the other end portion is a line electrode tip portion 6E. The width of the line electrode 6 is W2. Both the line electrodes 5 and 6 are made of indium tin oxide (ITO).
FIG. 8C shows a state where the information display panel obtained by bonding the back side substrate 1 and the display surface side substrate 2 is viewed from the display surface side. A square part surrounded by a dotted line is a display area. The length of the long side of the rectangular display area is X, and the length of the short side is Y. The lead wire portion 10 from each of the line electrodes 5 and 6 is connected to a drive device power circuit on the input side for applying a voltage between the line electrodes. It is connected.

FIG. 9 is a side view of the information display panel of the present invention shown in FIG.
As shown in the figure, when the thickness of the line electrode 5 provided on the back side substrate 1 is t1, and the thickness of the line electrode 6 provided on the display surface side substrate 2 is t2, the information display panel of the present invention is 0.05 μm. ≦ t2 ≦ 10 μm and the aspect ratio X / Y ≦ t1 / t2 of the display area is configured. If t2 is thinner than 0.05 μm, the electric resistance of the line electrode 6 is too large, and the voltage applied at the line electrode tip 6E becomes low. Moreover, the voltage waveform at the time of applying a voltage is distorted, resulting in a disadvantage that stable voltage application cannot be performed. On the other hand, when the electrode is thickened, the electric resistance is reduced, but when t2 is thicker than 10 μm, there is a disadvantage that the light transmittance is hindered.
In addition, since the electrical resistance of the electrode can be reduced as the thickness increases, the electrical resistance of the longer line electrode 5 arranged in the direction parallel to the long side increases when t1 / t2 is about the aspect ratio X / Y. As a result, the voltage applied at the line electrode tip 5E becomes low.

Further, it is preferable that the configuration is 0.05 μm ≦ t1 ≦ 20 μm. When t1 is thinner than 0.05 μm, the same disadvantage as described above occurs. On the other hand, if t1 is thicker than 20 μm, it is not related to light transmission because it is on the back side, but there is an inconvenience in production because it requires a great number of man-hours for electrode formation.
In order to ensure the distance between the back side substrate 1 and the display surface side substrate 2, an inter-substrate distance securing member 15 is provided. A cell provided between the substrates and a display medium sealed in the cell are omitted.

までであれば、問題のない精細度が得られるため、１≦Ｗ２／Ｗ１≦１．４１としている。 In the information display panel of the present invention, if the width of the line electrode provided on the back substrate is W1, and the width of the line electrode provided on the display substrate is W2, 50 μm ≦ W1, W2 ≦ 1000 μm and 1 ≦ W2 / It is preferable to configure so that W1 ≦ 1.41.
The electrode widths W1 and W2 both affect the pixel size and are preferably smaller for high definition (high resolution). However, if it is smaller than 50 μm, there is an inconvenience that the electric resistance becomes too large. This is inconvenient.
In the A7 to A3 and B7 to B3 size screens, W1 and W2 are preferably 50 μm to 500 μm, and more preferably 50 μm to 200 μm. On a large screen exceeding B3, even if W1 and W2 are both about 1000 μm, there is no problem in definition.
The case of W2 / W1 = 1 is a square pixel, which is most preferable in terms of definition, but the pixel shape is an aspect ratio.

If so, 1 ≦ W2 / W1 ≦ 1.41 is set because fineness without problems can be obtained.

  Note that the resolution is determined by the pixel size, and in the present invention in which the intersection of the opposing line electrodes is a pixel, the line electrode width determines the pixel size. When the width of the line electrode is reduced, the pixel size is reduced and the resolution is increased, but there is a disadvantage that the electric resistance is increased. On the other hand, when the electrode width is increased, the electrical resistance is lowered, but the pixel size is increased and the resolution is sacrificed. However, since there are uses for large screens that do not require high resolution, the upper limit of the panel size to which the present invention can be applied is not limited to B3.

In the information display panel of the present invention, the line electrodes 5 and 6 are made of indium tin oxide (ITO), indium oxide, zinc doped indium oxide (IZO), aluminum doped zinc oxide (AZO), antimony tin oxide (ATO). ), Conductive metal oxides such as conductive tin oxide and conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene.
These materials can be said to be good electrode materials in terms of transparency (light transmittance) and conductivity (low electrical resistance).

  Table 1 shows the vertical and horizontal lengths of the standard size information display panel. Since the information display panel has a frame portion that does not become a display portion, the panel size does not become the screen size (the size of the display area) as it is.

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

  As information display panel substrates, organic terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic, etc. A molecular substrate, a glass sheet, a quartz sheet, a metal sheet or the like is used, and a transparent one of them is used on the display surface (observation surface) side. The substrate used on the back (non-observation surface) side may be transparent or not transparent. The thickness of the substrate is preferably from 2 to 5000 μm, more preferably from 5 to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, it will be a thin information display panel. Is inconvenient.

  As a method for forming the electrode, the above-described materials are formed into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, etc., and a conductive agent is mixed with a solvent or a synthetic resin binder. A method is used. The above-mentioned material that can be patterned and is conductive on both the display-side substrate and the back-side substrate can be suitably used. The external voltage input may be superimposed with direct current or alternating current. A highly conductive material (metal material) is disposed at the joint between the electrode lead line part and the electrode so that there is no step due to the difference in thickness between the lead line part and the electrode.

In the partition for forming cells in the space between the substrates of the information display panel, the height and width of the partition are appropriately set according to the type of the display medium involved in the display and are not limited in general, but the partition width is 2 The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm. As shown in FIG. 10, the cells in the information display panel obtained by superimposing the display side substrate and the back side substrate 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. In addition, an elliptical shape or a racetrack shape may be used, and examples of the arrangement include a lattice shape, a line shape, a honeycomb shape, and a mesh shape. Various shapes of cells are used depending on the partition arrangement. It is better to make the portion corresponding to the partition cross section visible from the display surface side (the area of the cell frame formed by the partition width) as small as possible, and the display state becomes clearer.
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 preferably used, but among these, a photolithography method using a resist film and a mold transfer method are preferably used.

Next, charged particles (hereinafter also referred to as particles) that can be driven by an electric field and constitute a display medium in the information display panel of the present invention will be described. The particles are used as a display medium by being composed of the particles alone or as a display medium by being combined with other particles.
The particles can contain a charge control agent, a colorant, an inorganic additive, and the like, if necessary, in the resin as the main component, as in the conventional case. Examples of resins, charge control agents, colorants, and other additives will be given below.

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

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

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

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

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

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

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

  Moreover, the charged particles capable of being driven by an electric field used in the present invention preferably have an average particle diameter d (0.5) in the range of 1 to 20 μm, and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders movement as a display medium.

Further, in the charged particles capable of electric field driving used in the present invention, the particle size distribution Span shown in the following formula is set to less than 5, preferably less than 3, with respect to the particle size distribution of each particle.
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 movement as a display medium is possible.

  Furthermore, when using a plurality of display media, the smallest average particle with respect to d (0.5) of the charged particles showing the largest average particle diameter d (0.5) among the charged particles constituting the used display medium. It is important that the ratio of d (0.5) of charged particles indicating the diameter is 10 or less. Even if the particle size distribution Span is reduced, particles with different charging characteristics move in opposite directions, so that the display media particle sizes are close to each other, and each charged particle can easily move in the opposite direction by the equivalent amount. It is preferable to be within this range.

The particle size distribution and particle size of the particles 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 charged particles that can be driven by an electric field naturally depends on the measurement conditions, but the charge amount of particles in the information display panel is almost the initial charge amount, contact with the partition, contact with the substrate, and charge associated with elapsed time. It was found that depending on the attenuation, the saturation value of the charging behavior of the particles was the dominant factor.

  As a result of intensive studies, the present inventors have found that the range of appropriate charging characteristic values of particles can be evaluated by measuring the charge amount of particles using the same carrier particles in the blow-off method.

Furthermore, in the case of an information display panel that drives a display medium in a gas space, it is important to manage the gas in the gap surrounding the display medium, which contributes to improved display stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, and preferably 50% RH or less for the humidity of the gas in the gap.
For example, in FIG. 1 (a), the gap portion refers to the electrodes 5 and 6 (when electrodes are provided inside the substrate), the occupied portion of the display medium 3, from the portion sandwiched between the opposing substrate 1 and substrate 2. The gas portion in contact with the so-called display medium excluding the occupied portion of the partition wall 4 and the seal portion of the information display panel is assumed.
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 agent and a sealing method that prevent moisture from entering from the outside.

The distance between the substrates in the information display panel of the present invention is not limited as long as the display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 100 μm, preferably 10 to 50 μm.
The volume occupancy of the display medium in the gas space in the inter-substrate cell is preferably 5 to 70%, more preferably 5 to 60%. If it exceeds 70%, the movement of the display medium is hindered, and if it is less than 5%, the contrast tends to be unclear.

Examples of the information display panel of the present invention will now be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples.
An information display panel was manufactured by the following process.
(1) Partition wall (rib) and electrode pattern forming process on substrate (2) Display medium filling process on substrate (3) Unnecessary display medium removal process on partition wall (4) Adhesive layer formation on partition wall Step (5) Bonding Step of Two Substrates The formation of the electrode pattern by the step (1) will be described below.

<Example 1>
A 30Ω / □ ITO film (thickness: 0.05 μm) is formed on the surface of the A4 size display area (290 mm × 202 mm) of the 200 μm thick display surface side glass substrate, and the A4 of the 200 μm thick back side glass substrate is formed. After forming a 30 Ω / □ ITO film (thickness: 0.1 μm) on the surface of the size display region (290 mm × 202 mm), a line-like ITO electrode with a length of 202 mm and a width of 160 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 290 mm and a width of 140 μm was formed on the back side glass substrate by a photoresist method.
Thereafter, a 180 μm × 160 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are formed on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Example 2>
A 30 Ω / □ ITO film (thickness: 1 μm) is formed on the surface of the A4 size display area (290 mm × 202 mm) of the 200 μm thick display surface side glass substrate, and the A4 size display of the 200 μm thick back side glass substrate. After forming a 30 Ω / □ ITO film (thickness: 1.5 μm) on the surface of the region (290 mm × 202 mm), a line-like ITO electrode with a length of 202 mm and a width of 160 μm is formed on the display side glass substrate. On the glass substrate, line-like ITO electrodes having a length of 290 mm and a width of 140 μm were respectively formed by patterning using a photoresist method.
Thereafter, a 180 μm × 160 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are formed on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Example 3>
A 30Ω / □ ITO film (thickness: 2 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and a B3 size display of a 200 μm thick back side glass substrate After forming a 30 Ω / □ ITO film (thickness: 3 μm) on the surface of the region (493 mm × 340 mm), a line-like ITO electrode having a length of 340 mm and a width of 180 μm is formed on the display surface side glass substrate, and the back side glass substrate A line-like ITO electrode having a length of 493 mm and a width of 160 μm was patterned by a photoresist method.
Thereafter, a 200 μm × 180 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Example 4>
A 30Ω / □ ITO film (thickness: 10 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and a B3 size display of a 200 μm thick back side glass substrate. After forming a 30 Ω / □ ITO film (thickness: 15 μm) on the surface of the region (493 mm × 340 mm), a line-like ITO electrode having a length of 340 mm and a width of 180 μm is formed on the display surface side glass substrate, and the back side glass substrate A line-like ITO electrode having a length of 493 mm and a width of 160 μm was patterned by a photoresist method.
Thereafter, a 200 μm × 180 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Example 5>
A 30Ω / □ ITO film (thickness: 0.3 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and B3 of a 200 μm thick back side glass substrate is formed. After forming a 30Ω / □ ITO film (thickness: 1 μm) on the surface of the size display area (493 mm × 340 mm), a line-like ITO electrode with a length of 340 mm and a width of 180 μm is formed on the display side glass substrate. On the glass substrate, line-like ITO electrodes having a length of 493 mm and a width of 160 μm were patterned by a photoresist method.
Thereafter, a 200 μm × 180 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Example 6>
A 30Ω / □ ITO film (thickness: 0.08 μm) is formed on the surface of the A4 size display area (290 mm × 202 mm) of the 200 μm thick display surface side glass substrate, and the A4 of the 200 μm thick back side glass substrate is formed. After forming a 30 Ω / □ ITO film (thickness: 0.15 μm) on the surface of the size display region (290 mm × 202 mm), a line-like ITO electrode with a length of 202 mm and a width of 160 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 290 mm and a width of 140 μm was formed on the back side glass substrate by a photoresist method.
Thereafter, a 180 μm × 160 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are formed on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Comparative Example 1>
A 30Ω / □ ITO film (thickness: 0.05 μm) is formed on the surface of the A4 size display area (290 mm × 202 mm) of the 200 μm thick display surface side glass substrate, and the A4 of the 200 μm thick back side glass substrate is formed. After forming a 30 Ω / □ ITO film (thickness: 0.05 μm) on the surface of the size display region (290 mm × 202 mm), a line-like ITO electrode having a length of 290 mm and a width of 140 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 202 mm and a width of 140 μm was formed on the rear glass substrate by patterning using a photoresist method.
Thereafter, a 160 μm × 160 μm opening (this portion becomes a display cell) and a lattice-like partition wall pattern having a line width of 30 μm and a height of 40 μm are formed on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Comparative example 2>
A 30Ω / □ ITO film (thickness: 0.3 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and B3 of a 200 μm thick back side glass substrate is formed. After forming a 30 Ω / □ ITO film (thickness: 0.4 μm) on the surface of the size display region (493 mm × 340 mm), a line-shaped ITO electrode having a length of 340 mm and a width of 160 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 493 mm and a width of 160 μm was patterned on the rear glass substrate by a photoresist method.
Thereafter, a 180 μm × 180 μm opening (this part becomes a display cell) and a grid-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Comparative Example 3>
A 30Ω / □ ITO film (thickness: 0.3 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and B3 of a 200 μm thick back side glass substrate is formed. After forming a 30 Ω / □ ITO film (thickness: 0.4 μm) on the surface of the size display region (493 mm × 340 mm), a line-like ITO electrode having a length of 493 mm and a width of 160 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 340 mm and a width of 160 μm was patterned on the back glass substrate by a photoresist method.
Thereafter, a 180 μm × 180 μm opening (this part becomes a display cell) and a grid-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

<Comparative example 4>
A 30Ω / □ ITO film (thickness: 15 μm) is formed on the surface of a B3 size display area (493 mm × 340 mm) of a 200 μm thick display surface side glass substrate, and a B3 size display of a 200 μm thick back side glass substrate. After forming a 30 Ω / □ ITO film (thickness: 15 μm) on the surface of the region (493 mm × 340 mm), a line-like ITO electrode having a length of 340 mm and a width of 160 μm is formed on the display surface side glass substrate. A line-like ITO electrode having a length of 493 mm and a width of 160 μm was patterned by a photoresist method.
Thereafter, a 180 μm × 180 μm opening (this part becomes a display cell) and a grid-like partition wall pattern having a line width of 30 μm and a height of 40 μm are prepared on the display surface side substrate on which the ITO electrode is formed by a photoresist method. Thus, a substrate with a partition wall was obtained.
The white display medium (negatively charged) and the black display medium (positively charged) were combined and placed in the cell at the same volume so that the volume was 25 vol%, and then two substrates were bonded to obtain an information display panel.

  Using the information display panels of Examples 1 to 6 and Comparative Examples 1 to 4 described above, solid images were displayed to evaluate display performance. The conditions and results are shown in Table 2.

In Examples 1 to 6, when a solid image was displayed, a white solid image and a black solid image were displayed uniformly on the entire screen.
In Comparative Examples 1 to 3, when a solid image was displayed, the contrast of the screen portion corresponding to the tip of the line-shaped electrode was non-uniform in both the white solid image and the black solid image.
In Comparative Example 4, when the solid image was displayed, both the white solid image and the black solid image were displayed uniformly on the entire screen, but the entire screen was dark and the display state was very small.

  The information display panel of the present invention includes a notebook computer, an electronic notebook, a portable information device called PDA (Personal Digital Assistants), a display unit of a mobile device such as a mobile phone, a handy terminal, an electronic book, an electronic newspaper, an electronic manual ( Electronic paper such as instruction manuals, signboards, posters, bulletin boards such as blackboards (whiteboards), electronic desk calculators, display units for home appliances, automobile supplies, card display units such as point cards and IC cards, electronic advertisements, In addition to information boards, electronic POPs (Point Of Presence, Point Of Purchase advertising), electronic price tags, electronic shelf labels, electronic musical scores, RF-ID device displays, various electronic devices such as POS terminals, car navigation devices, watches, etc. It is suitably used for a dot matrix display type display unit.

  As a driving method of the information display panel of the present invention, a simple matrix driving method or a static driving method in which no switching element is used for the panel itself is suitable.

(A), (b) is a figure which shows an example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the other example of the information display panel of this invention, respectively. It is a figure which shows the further another example of the information display panel of this invention. It is a figure which shows the further another example of the information display panel of this invention. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the information display panel of this invention, respectively. It is a figure which shows the further another example of the information display panel of this invention. (A)-(c) is the example of arrangement | positioning of the line electrode in the information display panel of this invention. It is a side view of the information display panel of the present invention. An example of the partition in the information display panel of this invention is shown.

Explanation of symbols

1, 2 Substrate 3 Display medium 3W White display medium 3Wa White charged particle 3B Black display medium 3Ba Black charged particle 3Ra Red charged particle 3Ga Green charged particle 3BLa Blue charged particle 3Ma Magenta charged particle 3Ya Yellow charged particle 3Ca Cyan charged particle 4 Bulkhead 5, 6 Electrode 5C, 6C Line electrode connection part 5E, 6E Line electrode tip 7W White plate 7R Red plate 7G Green plate 7BL Blue plate 8 Insulating liquid 10 Lead wire part 11 Power connection member 12 Cell 13 Power supply 15 Substrate Inter-distance securing member 21 cell 21-1 first cell 21-2 second cell 21-3 third cell 22R red color filter 22G green color filter 22BL blue color filter

Claims (5)

By enclosing a display medium including charged particles that can be driven by an electric field between the substrates, and moving the display medium by applying an electric field from a counter electrode formed by crossing opposing line electrodes provided on the substrate In an information display panel having a rectangular dot matrix type display area that can rewrite information display such as images,
A transparent line electrode having a thickness t1 is provided on the back side substrate in a direction parallel to the long side of the display region,
A transparent line electrode having a thickness t2 is provided on the display surface side substrate in a direction parallel to the short side of the display region,
0.05 μm ≦ t2 ≦ 10 μm and the aspect ratio of the display area ≦ t1 / t2
An information display panel characterized by being configured as follows.   2. The information display panel according to claim 1, wherein the line electrode provided on the back side substrate and the line electrode provided on the display side substrate are formed of the same material. The thickness t1 of the line electrode provided on the back side substrate is
0.05μm ≦ t1 ≦ 20μm
The information display panel according to claim 1, wherein the information display panel is configured as follows. When the width of the line electrode provided on the back side substrate is W1, and the width of the line electrode provided on the display surface side substrate is W2,
50 μm ≦ W1, W2 ≦ 1000 μm and 1 ≦ W2 / W1 ≦ 1.41
The information display panel according to claim 1, wherein the information display panel is configured as follows.   The line electrode is formed of any one of indium tin oxide, indium oxide, aluminum-doped zinc oxide, zinc-doped indium oxide, antimony tin oxide, conductive tin oxide, conductive zinc oxide, polyaniline, polypyrrole, and polythiophene. The information display panel according to claim 1, wherein the information display panel is a display panel.

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