JP2009128766A - Panel for information display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a panel for information display for always displaying a sharp image without reducing whiteness or blackness degree. <P>SOLUTION: The panel for dot matrix information display which includes a display medium including particles to be driven by electric field sealed in a cell space separated from each other by a partition between substrates, and moves the display medium with an electric field to be applied from counter electrodes provided on both substrate sides, so that rewrites displayed information on images or the like. One display unit (also referred to as one pixel) comprises a cell so that the display medium sealed in the cell comprises a colored charged particle and a transparent colorless charged particle having the charge polarity opposite to that of the colored charged particle. The cell is provided with a central projecting member so that the color of at least the top face of the central projecting member has a color different from that of the colored charged particle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention encloses a display medium including particles that can be driven by an electric field in a cell space that is isolated from each other by a partition wall between the substrates, and applies an electric field from a counter electrode provided on both substrates. The present invention relates to an information display panel of a dot matrix display system in which information display such as an image can be rewritten by moving.
The present invention relates to a dot matrix type information display panel.

  Conventionally, as a display panel used in an information display device that replaces a liquid crystal display device (LCD), a display method in which charged particles are moved in a liquid (electrophoresis method), or a display method in which charged particles are moved in a gas (in the air) There is known an information display device equipped with an information display panel of a movement type).

  As the charged particle movement type display panel, at least one kind of display medium composed of at least one kind of particles and having optical reflectivity and chargeability is provided in a space between two opposing substrates, at least one of which is transparent. A device using an information display panel of a type that displays information such as an image by moving the display medium by applying an electric field to the display medium by encapsulating the display medium is known (for example, Patent Document 1).

  A representative example of an information display panel that drives an electric field on a display medium composed of the above-described charged particles will be described with reference to FIGS. A display medium 33 composed of charged particles capable of driving an electric field is enclosed in a space between two substrates 31 and 32, and an electric field is applied from electrodes 35 and 36 provided on the substrates 31 and 32, respectively. An information display panel of a dot matrix type display system capable of rewriting information display such as an image by moving the medium 33 is shown. The space between the substrates 31 and 32 enclosing the display medium 33 is partitioned by a plurality of cells (small rooms) 37 by partition walls 34. Thereby, it is possible to prevent the enclosed display medium 33 from being biased.

  In the example shown in FIGS. 17A and 17B, each cell 37 is filled with a display medium of a combination of two colors, a white display medium 33W and a black display medium 33B, and is displayed in black and white dots. In both FIGS. 17A and 17B, the white display is performed on the observer by moving all the white display media to the display surface side substrate. The difference between FIG. 17A and FIG. 17B is that in the example shown in FIG. 17A, a pixel (display unit) is configured by a counter electrode formed by intersecting line electrodes 35 and 36. On the other hand, in the example shown in FIG. 17B, the pixel (display unit) is constituted by a counter electrode composed of the individual electrodes 35 and 36. The internal space of the cell may be filled with gas or filled with an insulating liquid.

  In the example shown in FIGS. 18A and 18B, three cells 37 are used as display units (one pixel: one dot), and three primary color filters 41R, 41G, and 41BL are arranged on the viewing side of each cell 37. In addition, the color display is performed by the display medium of two colors of the white display medium 33W and the black display medium 33B. In FIGS. 18A and 18B, blue dots are displayed to the observer. The difference between FIG. 18A and FIG. 18B is the counter electrode formed by intersecting line electrodes 35 and 36 corresponding to three cells serving as display units in the example shown in FIG. 18A. While one pixel (pixel) is configured, in the example shown in FIG. 18B, one pixel is configured by counter electrodes including individual electrodes 35 and 36 corresponding to three cells serving as display units. Is a point. The internal space of the cell may be filled with gas or filled with an insulating liquid.

International Publication No. 2003/050606 Pamphlet

  In the above-mentioned information display panel using the charged particle movement method, a cell formed of a partition or a microcapsule type cell is disposed between two substrates, and each of the cells can be driven with two colors of electric fields. A display medium (for example, white charged particles and black charged particles) is enclosed, and an information image is displayed by moving two color display media in one cell. Since the two-color display media try to move in directions opposite to each other with respect to the electric field, they sometimes collide with each other and cannot move smoothly. For this reason, there is a problem that a black display medium is partially mixed when white images are displayed and the whiteness is lowered, and conversely, a white display medium is mixed and blackness is reduced when black images are displayed. In particular, since the white charged particles and the black charged particles are substantially the same size, there is also a problem in that the adverse effect due to the collision when moving in the opposite directions is likely to occur.

  An object of the present invention is to solve the above-described problems and provide an information display panel capable of displaying a clear image at any time without reducing whiteness and blackness.

  According to a first aspect of the information display panel of the present invention, a display medium comprising particles that can be driven by an electric field is enclosed in a cell space separated from each other by a partition wall between the substrates, and the counter electrode provided on both substrate sides In an information display panel of a dot matrix display system in which information display such as an image can be rewritten by moving a display medium by applying an electric field from a display unit, one display unit (also referred to as one pixel) is configured by one cell. The display medium to be enclosed in each cell is composed of colored charged particles and transparent colorless charged particles having the opposite charging polarity to the colored charged particles, and each cell is provided with a central convex member, The color of at least the upper surface of the member is different from the color of the colored charged particles. For example, in an information display panel using a display medium composed of black positively charged particles and transparent colorless negatively charged particles, black particles and transparent colorless particles move in opposite directions with respect to the electric field. Black and white dot display can be performed by the black particles and the color (for example, white) of at least the upper surface of the central convex member.

  According to a second invention of the information display panel of the present invention, a display medium comprising particles that can be driven by an electric field is enclosed in a cell space separated from each other by a partition wall between the substrates, and the counter electrode provided on both substrate sides In an information display panel of a dot matrix display system in which information display such as an image can be rewritten by moving a display medium by applying an electric field, one display unit (also referred to as one pixel) is composed of a plurality of cells. The display medium enclosed in at least one cell is composed of colored charged particles of the first color and transparent and colorless charged particles having a charging polarity opposite to the colored charged particles of the first color, and at least another A colored charged particle having a charging polarity opposite to the charged polarity of the first colored particle, the colored charged particle of the second color, and the colored charged particle of the second color; Is Each cell is provided with a central convex member, and the color of at least the upper surface of the central convex member is the color of the colored charged particles enclosed in the cell. Is a different color, and is characterized by being the same color as the colored charged particles encapsulated in another cell. Dot matrix display is performed by arranging at least two or more cells encapsulating colored particles of different colors as one display unit and aligning the positions of the one display unit and one counter counter electrode in a matrix. For example, in an information display panel using a display medium composed of black positively charged particles and transparent colorless negatively charged particles, and a display medium composed of white negatively charged particles and transparent colorless positively charged particles, each cell , Black particles and transparent colorless particles, and white particles and transparent colorless particles move in opposite directions with respect to the electric field. Black and white dot display can be performed by black particles and black and white particles on at least the upper surface of the central convex member and white color on at least the upper surface of the central convex member.

  In the first and second inventions of the information display panel of the present invention, the average particle diameter of the transparent and colorless charged particles is smaller than the average particle diameter of the colored charged particles enclosed in the same cell, A space formed by the shaped member and the partition wall forming the cell is a space in which the display medium is disposed, the central convex member is provided in the center of the cell on the back side substrate, and the central convex member It is preferable to form a space in which the display medium is arranged between all the partition walls forming the cell.

In the first invention and the second invention of the information display panel of the present invention, the height Ht of the central convex member is relative to the distance Hw between the substrates.
Hw / 4 ≦ Ht ≦ Hw / 2
It is preferable to satisfy.

In the first and second inventions of the information display panel of the present invention, the distance Wt between the side surface portion of the central convex member and the partition wall in the space in which the display medium is arranged is the particle constituting the display medium. For the average particle diameter d (0.5)
3 × d (0.5) ≦ Wt
It is preferable to satisfy.

In the first and second inventions of the information display panel of the present invention, the height Ht of the central convex member and the distance Hw between the substrates are the average particle diameter d (0) of the particles constituting the display medium. .5)
3 × d (0.5) ≦ Hw
2 × d (0.5) <Hw−Ht
It is preferable to satisfy.

  According to the first and second inventions of the present invention, since one color colored charged particle is moved within one cell to display an information image, some black particles are mixed when displaying a white image. As a result, the whiteness is not lowered, and the blackness in which some white particles are mixed at the time of displaying the black image is not lowered, and the display image quality is improved. In addition, two types of charged particles having opposite charging polarities in one cell are colored charged particles and colorless transparent charged particles, and the size of the colorless and transparent charged particles is smaller than the size of the colored charged particles. The problem that the charged particles rub against each other at the time of movement to maintain the charged state and are difficult to move with each other has been solved, and the problem that the information image cannot be displayed has been eliminated.

  First, the basic configuration of the information display panel of the present invention will be described. In the information display panel of the present invention, an electric field is applied to a display medium having optical reflectivity and chargeability, which is composed of at least one kind of electric field driveable particles enclosed in a space between two opposing substrates. Is granted. In accordance with the applied electric field direction, the charged display medium is attracted by the electric field force or the Coulomb force, and the display medium is moved by the change in the electric field direction, whereby information such as an image is displayed. Therefore, it is necessary to design the information display panel so that the display medium can move uniformly and maintain stability when rewriting the display repeatedly or when displaying the display information continuously. Here, the force applied to the particles constituting the display medium includes, in addition to the force attracted by the Coulomb force between the particles, the electric mirror image force between the electrode, the substrate, and the central convex member, the intermolecular force, the liquid crosslinking force, the gravity And so on.

  Examples of the information display panel of the present invention will be described with reference to FIGS. 1 (a) and 1 (b) to FIGS. 5 (a) and 5 (b).

  In the example shown in FIGS. 1A and 1B, a display medium 3 composed of black positively charged particles 3B + and transparent colorless negatively charged particles 3T− is enclosed in a cell 7 formed of partition walls 4, In this cell, one display unit (pixel) is used. The black positively charged particles 3B + and the transparent colorless negatively charged particles 3T− are formed by intersecting the electrode 5 (line electrode) provided on the back side substrate 1 and the electrode 6 (line electrode) provided on the front side transparent substrate 2. In accordance with the electric field generated by applying a voltage between the counter electrodes, the electrodes move in the opposite directions perpendicular to the substrates 1 and 2. The back side substrate 1 in each cell 7 is provided with a white central convex member 11W having at least a white upper surface.

  In the example shown in FIGS. 1A and 1B, the black positively charged particles 3B + moving toward the back side substrate 1 come to be located at the end of the cell 7, and are not visible to the observer. The white color of the white central convex member 11W is visible through the transparent colorless negatively charged particles 3T-. In the example shown in FIG. 1A, black and white alternate dot display is performed in 6 display units (pixels), and in the example shown in FIG. 1B, black is displayed on 3 display boards in 6 display units (pixels). / Displayed in white.

  In the example shown in FIGS. 2A and 2B, the cell 8 enclosing the display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T +, and black positively charged particles 3B + / transparent colorless negatively charged One display unit (pixel) is composed of two cells, a cell 7 in which a display medium 3 composed of particles 3T- is enclosed. The display medium 3 uses an external counter electrode composed of an external electrode 5 provided outside the back-side substrate 1 and an external electrode 6 provided on the front-side transparent substrate 2 corresponding to a display unit as an external electric field forming unit. In accordance with an electric field generated by applying a voltage to the pair, each cell moves in a direction opposite to each other and perpendicular to the substrates 1 and 2. The back side substrate 1 in the cell 8 in which the display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T + is enclosed is provided with a black central convex member 11B having at least a black upper surface. The back side substrate 1 in the cell 7 enclosing the display medium 3 composed of the charged particles 3B + / transparent colorless negative charged particles 3T- is provided with a white central convex member 11W having at least a white upper surface. Reference numerals 12 and 13 are conductive members provided on the inner surfaces of the substrates 1 and 2, respectively. These conductive members are involved in the adhesion between the particles constituting the display medium and the substrate, and are based on the optimum design of conductivity. Although provided, it is not necessary to provide it.

  In the example shown in FIGS. 2A and 2B, the display medium 3 moving toward the back-side substrate 1 comes to be positioned at the end of the cell 7 or the cell 8 according to the direction of the electric field, The color of the central convex member of each cell 7 or cell 8 is visible through the transparent colorless particles without being visible to the observer. In the example shown in FIG. 2A, a panel that is displayed in black in three display units (pixels) is rewritten by external electric field forming means (external counter electrode). In the example shown in FIG. 2B, the panel rewritten so as to display white in 3 display units (pixels) is observed.

  In the example shown in FIGS. 3A and 3B, the cell 8 enclosing the display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T +, and black positively charged particles 3B + / transparent colorless negatively charged One display unit (pixel) is composed of two cells, a cell 7 in which a display medium 3 composed of particles 3T- is enclosed. The display medium 3 is a counter electrode formed by intersecting an electrode 5 (line electrode) provided on the back-side substrate 1 and an electrode 6 (line electrode) provided on the front-side transparent substrate 2 corresponding to the display unit. In accordance with an electric field generated by applying a voltage between them, they move perpendicularly to the substrates 1 and 2 in opposite directions. The back side substrate 1 in the cell 8 in which the display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T + is enclosed is provided with a black central convex member 11B having at least a black upper surface. The back side substrate 1 in the cell 7 enclosing the display medium 3 composed of the charged particles 3B + / transparent colorless negative charged particles 3T- is provided with a white central convex member 11W having at least a white upper surface.

  In the example shown in FIGS. 3A and 3B, the display medium 3 moving toward the back side substrate 1 is positioned at the end of the cell 7 or the cell 8 according to the direction of the electric field. The color of the central convex member of each cell 7 or cell 8 is visible through the transparent colorless particles without being visible to the observer. In the example shown in FIG. 3A, an example in which black display is performed in three display units (pixels) is shown, and in the example shown in FIG. 3B, an example in which white display is performed in three display units (pixels). Show.

  In the example shown in FIGS. 4A and 4B, a cell 7 enclosing a display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T +, and red positively charged particles 3R + / transparent colorless negatively charged One display unit (pixel) is composed of two cells, a cell 8 in which a display medium 3 composed of particles 3T- is enclosed. The display medium 3 is a counter electrode formed by intersecting an electrode 5 (individual electrode) provided on the back-side substrate 1 and an electrode 6 (individual electrode) provided on the front-side transparent substrate 2 corresponding to the display unit. In accordance with an electric field generated by applying a voltage between them, they move perpendicularly to the substrates 1 and 2 in opposite directions. The back side substrate 1 in the cell 7 in which the display medium 3 composed of the white negatively charged particles 3W− / transparent colorless positively charged particles 3T + is enclosed is provided with a red central convex member 11R having at least an upper surface that is red. The back side substrate 1 in the cell 8 in which the display medium 3 composed of the charged particles 3R + / transparent colorless negative charged particles 3T- is enclosed is provided with a white central convex member 11W having at least a white upper surface.

  In the example shown in FIGS. 4A and 4B, the display medium 3 moving toward the back side substrate 1 comes to be positioned at the end of the cell 7 or the cell 8 according to the direction of the electric field, The color of the central convex member of each cell 7 or cell 8 is visible through the transparent colorless particles without being visible to the observer. In the example shown in FIG. 4A, an example in which white display is performed in three display units (pixels) is shown, and in the example shown in FIG. 4B, an example in which red display is performed in three display units (pixels). Show.

  In the example shown in FIGS. 5A and 5B, a cell 7 enclosing a display medium 3 composed of white negatively charged particles 3W− / transparent colorless positively charged particles 3T + and black positively charged particles 3B + / transparent colorless negatively charged A color filter 15 (a red color filter 15R, a green color filter 15G, and a blue color filter 15BL) is provided in units of two cells, the cell 8 in which the display medium 3 composed of the particles 3T- is enclosed, and 1 in 6 cells. A display unit (pixel) is used. The display medium 3 is formed by intersecting an electrode 5 (individual electrode) provided on the back surface side substrate 1 and an electrode 6 (individual electrode) provided on the front surface side transparent substrate 2 corresponding to the unit in which each color filter is provided. In accordance with the electric field generated by applying a voltage between the counter electrodes, the electrodes move in the opposite directions perpendicular to the substrates 1 and 2. The back side substrate 1 in the cell is provided with a white central convex member 11W having at least a white upper surface.

  In the example shown in FIGS. 5A and 5B, the display medium 3 moving toward the back side substrate 1 comes to be positioned at the end of the cell 7 or the cell 8 according to the direction of the electric field, The color of the white central convex member 11W of each cell 7 or cell 8 can be seen through the transparent colorless particles and the color filter, or the white or black display medium on the display surface side can be seen through the color filter. In the example shown in FIG. 5A, a white display is shown in one display unit (pixel), and in the example shown in FIG. 5B, a red display is shown in one display unit (pixel). Show.

  Next, each component in the information display panel of the present invention described above will be described.

  Although there is no restriction on the number and arrangement of a plurality of cells each enclosing two different colors of display media, the number of cells arranged in one display unit is increased because the area of one display unit depends on the definition of the displayed image. For this purpose, the cell area must be reduced, which makes it difficult to produce. Therefore, the number of cells is preferably in the range of 2 to 16.

  A central convex member is provided for each cell on the back substrate side. When the display medium enclosed in the cell is moved to the back side so as not to be used for display, the display medium moves so as to be guided to the cell wall side by the central convex member.

  The central convex member is provided at the center of the cell, and four sides of the cell wall can be opened, or one side, two sides, and three sides can be opened. The display medium moves and fits in the gap between the central convex member and the cell wall.

  The color of the central convex member is preferably white or transparent and colorless, or the same color as the color of the other display medium different from the color of the display medium enclosed in the same cell. For example, when performing black and white display with a cell encapsulating a white display medium and a cell encapsulating a black display medium, the cell encapsulating the black display medium is provided with a black central convex member in the cell encapsulating the white display medium. Is provided with a white central convex member. This improves both the white density and black density of the display screen.

  The information display panel is formed by enclosing a plurality of cells (small chambers) containing a display medium between substrates so that dot matrix display is possible, and arranging line electrodes formed on each of the two substrates orthogonally. The display medium can be driven by the matrix-like counter electrode pair.

  The information display panel includes a plurality of cells (small chambers) containing a display medium enclosed between the substrates so that dot matrix display is possible, and the display medium is formed by a matrix-like counter individual electrode pair formed on each of the two substrates. Can also be driven.

The cells are arranged in a lattice shape, but the shape may be any of a polygon such as a triangle, a quadrangle, a pentagon, and a hexagon, a circle, an ellipse, and a racetrack, or a combination of different shapes. Of these, polygons with rounded corners (especially quadrangles with rounded corners), circles, ellipses, and racetracks are preferred as the display medium that is easy to move.
The shape of the partition walls 4 forming the cells is appropriately set according to the type of display medium involved in display, the shape and arrangement of electrodes to be arranged, and is not limited in general. However, the width of the partition walls is preferably 2 to 100 μm, preferably Is adjusted to 3 to 50 μm, and the height of the partition wall is adjusted to 10 to 500 μm, preferably 10 to 200 μm.
In order to obtain flexibility of the information display panel, it is preferable that the height of the partition wall is low, and in order to obtain a high electric field by applying a low voltage, it is preferable that the height of the partition wall is low. The height is adjusted to 10 to 100 μm, preferably 10 to 50 μm.
In forming the partition wall, a both-rib method in which ribs are formed on each of the opposing substrates 1 and 2 and then bonded, and a single-rib method in which ribs are formed only on one substrate are conceivable. In the present invention, any method is preferably used.
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.

  Plastic substrates such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic A substrate or a glass substrate is used. Of these, a transparent one is used on the display surface side. The back side may not be transparent.

  The central convex member is made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic, etc. It can be easily formed by embossing a plastic sheet. Convex member formation such as embossing is performed after electrode formation is performed on a plastic sheet using a photolithographic method, a printing method, a sputtering method, a vacuum deposition method, a CVD (chemical vapor deposition) method, or a coating method. As the plastic-based sheet forming the central convex member, an acrylic, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), or polypropylene (PP) sheet excellent in rollability is particularly preferable.

  The plastic sheet on which the electrode and the central convex member are formed can be affixed to another sheet as a back side substrate, or the plastic sheet can be used as the back side substrate as it is.

  A combination of a cell containing a white display medium and a cell containing a black display medium, combined with a color filter of one color, applied to each color filter (three primary colors and colorless) for color display. You can also. The combination of a cell encapsulating a white display medium and a cell encapsulating a black display medium is one cell enclosing a white display medium, one cell encapsulating a black display medium, or encapsulating a white display medium. Two cells can be used, and one cell containing a black display medium can be used. In color display, it is preferable to combine a large number of cells in which a white display medium is enclosed, because reflection efficiency is improved and a bright display is obtained. Also in this case, the display state can be adjusted by changing the number of cells arranged for each color filter.

Next, white charged particles and black charged particles constituting the display medium in the information display panel of the present invention, and colorless and transparent charged particles as another particle group will be described. These charged particles may be used as they are, consisting of the charged particles alone or in combination with other particles.
These charged particles may 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 constituting the charged particles, 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, a styrene acrylic resin, an acrylic resin, an acrylic fluororesin, and a polyethylene resin are suitable from the viewpoint of controlling the adhesive force with the substrate.

Examples of the positively chargeable charge control agent include charge control resins such as polyamine resins, tertiary amino group-containing copolymers, and quaternary ammonium base-containing copolymers, imidazole compounds, nigrosine dyes, quaternary ammonium salts, and triglycerides. An aminotriphenylmethane compound or the like can be used.
Examples of negatively chargeable charge control agents include sulfonic acid group-containing copolymers, sulfonate group-containing copolymers, carboxylic acid group-containing copolymers, and charge control resins such as carboxylic acid group-containing copolymers, and Cr. Azo dyes containing metals such as Co, Al, and Fe, salicylic acid metal compounds, and alkylsalicylic acid metal oxides.
Among the above charge control agents, it is preferable to use a charge control resin, and the charge control resin preferably has a content of a functional group imparting chargeability of 0.5 to 15% by weight, and preferably 1 to 10% by weight. % Is more preferable.

  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.
Depending on the presence or absence of the colorant, colored charged particles and colorless transparent charged particles having a desired color can be produced.

  Further, the colored charged particles of 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.

Furthermore, in the present invention, regarding the particle size distribution of the charged particles, the particle size distribution Span represented by the following formula is set to less than 5, preferably less than 3.
Span = (d (0.9) −d (0.1)) / d (0.5)
(However, d (0.5) is a numerical value 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 charged particle is uniform, and movement as a uniform display medium becomes possible.

It is important to make the average particle diameter d (0.5) of the transparent colorless charged particles smaller than the average particle diameter d (0.5) of the colored charged particles constituting the display medium. Since the colored charged particles and the transparent colorless charged particles have different charging polarities, they move in opposite directions. If the particle sizes are the same, adverse effects due to collision are likely to occur. Therefore, by reducing the size of the transparent and colorless charged particles, particles having different polarities can move easily.
The average particle diameter (0.5) of the transparent colorless charged particles is preferably about 30 to 90% of the average particle diameter d (0.5) of the colored charged particles. The charged particles are less likely to adhere to the particles, causing inconveniences in the mobility of the charged particles. If it exceeds 90%, there is an inconvenience that adverse effects due to collision between the charged particles easily occur.

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 charged amount of the charged particles naturally depends on the measurement conditions, but the charged amount of the charged particles in the information display panel is almost dependent on the initial charge amount, the contact with the partition wall, the contact with the substrate, and the charge decay with the elapsed time. In particular, it was found that the saturation value of the charging behavior of the charged particles is a dominant factor.
As a result of intensive studies, the present inventors have found that by measuring the charge amount of the charged particles using the same carrier particles in the blow-off method, it is possible to evaluate the range of the appropriate charging characteristic value of the charged particles.

Furthermore, when applied to an information display panel in which a display medium composed of charged particles is driven in a gas space, it is important to manage the gas in the gap surrounding the display medium between the substrates, and display stability. Contributes to improvement. 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) and FIG. 1 (b), the void portion refers to the portion occupied by the central convex member 11 from the portion sandwiched between the opposing substrate 1 and substrate 2, and the electrodes 5 and 6 (electrodes inside the substrate). In other words, the gas portion in contact with the so-called display medium excluding the occupied portion of the display medium 3, the occupied portion of the partition wall 4, and the seal portion of the information display panel is meant.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas must be sealed in the information display panel so that the humidity is maintained. For example, filling of particles constituting the display medium, assembly of the information display panel, etc. are performed in a predetermined humidity environment. In addition, it is important to apply a sealing agent and a sealing method for preventing moisture from entering from the outside.

The distance between the substrates in the information display panel is not limited as long as the display medium can be moved and the contrast can be maintained, but in the present invention, it is adjusted to 10 to 100 μm, preferably 10 to 50 μm.
The volume occupancy of the display medium (colored charged particles and transparent colorless charged particles) in the space in the cell between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. When it exceeds 70%, the movement as a display medium is hindered, and when it is less than 5%, the contrast tends to be unclear.

  A configuration example of the cell of the information display panel of the present invention will be described with reference to FIGS. 6 (a), 6 (b) to 10 (a) to 10 (c). In each cell, the electrodes 5 and 6 serving as counter electrodes are arranged so as to be in contact with the display medium sealed inside the cell. In this case, it is preferable to arrange the electrode edges so as not to be hidden by the partition walls.

  FIGS. 6A to 8A are top views of cells of the information display panel of the present invention, and FIGS. 6B to 8B are FIGS. 6A to 8A, respectively. It is AA sectional drawing. 6 to 8, in each case, a central convex member 11 is provided at the center of a quadrangular cell, and a space is provided between the central convex member 11 and the four partition walls 4 forming the cell. In this space, a display medium attracted to the electrode of the back side substrate is arranged. The difference between FIGS. 6 to 8 is the shape of the central convex member 11, as shown in the cross-sectional view. In FIG. 6B, the central convex member 11 has a curved shape with a large curvature radius at the upper part. In FIG. 7B, the central convex member 11 has a triangular roof shape, and in FIG. 8B, the central convex member 11 has a shape in which a triangular roof is superimposed on a prism.

In addition, as shown in FIG.6 (b), the height Ht of the center convex-shaped member 11 is with respect to the distance Hw between the electrodes 5 and 6 which oppose.
Hw / 4 ≦ Ht ≦ Hw / 2
It is preferable to satisfy. In the case of Ht <Hw / 4, the particles constituting the display medium may not be stored in the space between the central convex member 11 and the partition wall 4 and may be disposed on the central convex member 11. Further, when Hw / 2 <Ht, the particles constituting the display medium are unlikely to move on the upper part of the central convex member 11, and may not easily spread over the entire substrate surface serving as the display surface.

Further, in the case where a space is provided between the central convex member 11 and at least one of the partition walls 4 forming the cell, the distance Wt between the central convex member 11 and the partition wall 4 constitutes the display medium. For the average particle diameter d (0.5) of the particles,
3 × d (0.5) ≦ Wt
It is preferable to satisfy. When it is not in the above range, the particles constituting the display medium may not easily move into the space between the central convex member 11 and the partition wall 4 or may not fit.

Further, the height Ht of the central convex member 11 and the distance Hw between the substrates are relative to the average particle diameter d (0.5) of the particles constituting the display medium.
3 × d (0.5) ≦ Hw
2 × d (0.5) <Hw−Ht
It is preferable to satisfy. The above range is set because the particles constituting the display medium are difficult to move when the distance Hw-Ht from the display surface side substrate to the central convex member is small, and the display medium is configured when the distance Hw-Ht is large. This is because it is necessary to increase the drive voltage in order to move the particles to be moved.

  FIGS. 9A and 10A are top views of cells as other examples of the information display panel of the present invention. FIGS. 9B and 10B are FIGS. 9A and 9B, respectively. FIG. 9A is a cross-sectional view taken along line AA, and FIGS. 9C and 10C are cross-sectional views taken along line BB in FIG. 9A and FIG. 10A, respectively. 9 and 10, the central convex member 11 is provided so as to be in contact with the opposing two-side partition walls of the rectangular cell, and a space is provided between the other two-side partition walls and the central convex member 11. In this space, the display medium attracted to the electrode of the back side substrate is arranged. In FIG. 9, the partition wall in contact with the central convex member 11 is the long side of the cell, and in FIG. 10, the partition wall 4 in contact with the central convex member 11 is the short side of the cell. The other difference between FIG. 9 and FIG. 10 is in the shape of the central convex member 11 as shown in the cross-sectional view, and the central convex member 11 is in the shape of a triangular roof as shown in FIG. As shown in FIG. 10C, the central convex member 11 has a shape in which a triangular roof is superimposed on a prism. The cross-sectional shape in the horizontal direction of the central convex member is preferably matched with the cell shape, and is preferably a square with rounded corners. In order to obtain the ease of movement of the display medium, the side surfaces are preferably smooth.

  Next, a configuration example of one display unit of the information display panel of the present invention will be described based on FIGS. 11 (a) and (b) to FIGS. 16 (a) and 16 (b). 11 (a) to 16 (a) are displayed in white, and FIGS. 11 (b) to 16 (b) are displayed in black corresponding to FIGS. 11 (a) to 16 (a). It is a structural example of 1 display unit of the information display panel of this invention.

  In the example shown in FIGS. 11A and 11B, one display unit is composed of two cells, one cell enclosing a white display medium and one cell enclosing a black display medium so as to be surrounded by a dotted line in the figure. is doing. In the example shown in FIGS. 12A and 12B, one display unit is composed of six cells including four cells enclosing a white display medium and two cells enclosing a black display medium so as to be surrounded by a dotted line in the figure. is doing. In the example shown in FIGS. 13A and 13B, one display unit is composed of six cells including four cells enclosing a white display medium and two cells enclosing a black display medium so as to be surrounded by a dotted line in the figure. is doing. In the example shown in FIGS. 14A and 14B, one display unit is configured by six cells including three cells enclosing a white display medium and three cells enclosing a black display medium so as to be surrounded by a dotted line in the figure. is doing. The examples shown in FIGS. 15A and 15B and FIGS. 16A and 16B are shown in FIGS. 11A and 11B and FIGS. 14A and 14B, respectively. The shape of the example and the central convex member 11 is different. 15 (a), 15 (b) and FIGS. 16 (a), 16 (b), one display unit is surrounded by a dotted line in the figure and one cell enclosing a white display medium is displayed in black. It is composed of two cells and one cell enclosing the medium.

  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, Information board, electronic POP (Point Of Presence, Point Of Purchase advertising), electronic price tag, electronic shelf label, electronic score, display part of RF-ID equipment, display part of various electronic equipment such as POS terminal, car navigation device, clock Besides, it is suitably used for a display portion (so-called rewritable paper) for rewriting display by an external electric field forming means. .

  The information display panel driving method of the present invention is a simple matrix driving method or static driving method that does not use a switching element in the panel itself, a three-terminal switching device represented by a thin film transistor (TFT), or a thin film diode ( Various types of driving methods such as an active matrix driving method using a two-terminal switching element represented by TFD) can be applied.

(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. (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. (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 an example of the cell structure of the information display panel of this invention, respectively. (A), (b) is a figure which shows the other example of the cell structure of the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the cell structure of the information display panel of this invention, respectively. (A)-(c) is a figure which shows the further another example of the cell structure of the information display panel of this invention, respectively. (A)-(c) is a figure which shows the further another example of the cell structure of the information display panel of this invention, respectively. (A), (b) is a figure which shows an example of a structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a figure which shows the other example of a structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a figure which shows the further another example of the structure of 1 display unit in the information display panel of this invention, respectively. (A), (b) is a typical example of the conventional charged particle electric field drive system display panel, respectively. (A), (b) is another typical example of the conventional charged particle electric field drive type display panel, respectively.

Explanation of symbols

1, 2 Substrate 3B + Black positively charged particle 3W- White negatively charged particle 3T- Transparent colorless negatively charged particle 3T + Transparent colorless positively charged particle 3R + Red positively charged particle 4 Bulkhead 5, 6 Electrode 7, 8 Cell 11 Central convex member 11B Black Central convex member 11W White central convex member 11R Red central convex member 12, 13 Conductive member 15 Color filter 15R Red color filter 15G Green color filter 15BL Blue color filter

Claims (8)

A display medium including particles that can be driven by an electric field is sealed in a cell space separated from each other by a partition between the substrates, and the display medium is moved by applying an electric field from a counter electrode provided on both substrates. In the information display panel of the dot matrix type display method that can rewrite the information display of images etc. by
One display unit (also referred to as one pixel) is composed of one cell, and the display medium enclosed in each cell is composed of colored charged particles and transparent colorless charged particles having a charging polarity opposite to the colored charged particles. Each cell is provided with a central convex member, and at least the upper surface of the central convex member has a color different from the color of the colored charged particles. A display medium including particles that can be driven by an electric field is sealed in a cell space separated from each other by a partition between the substrates, and the display medium is moved by applying an electric field from a counter electrode provided on both substrates. In the information display panel of the dot matrix type display method that can rewrite the information display of images etc. by
One display unit (also referred to as one pixel) is composed of a plurality of cells, and the display medium enclosed in at least one cell is charged oppositely to the first colored charged particles and the first colored charged particles. The display medium is composed of transparent and colorless charged particles having a polarity, and the display medium enclosed in at least another cell is a colored charged particle of the second color and has a charged polarity opposite to the charged polarity of the first colored particle Each of the cells is provided with a central convex member, and each of the cells is provided with a central convex member. The colored charged particles have a charged polarity opposite to that of the colored charged particles of the second color. An information display panel, wherein the color of at least the upper surface is the same as the color of the colored charged particles encapsulated in another cell, which is different from the color of the colored charged particles encapsulated in the cell.   3. The information display panel according to claim 1, wherein the average particle size of the transparent and colorless charged particles is smaller than the average particle size of the colored charged particles enclosed in the same cell.   The information display according to any one of claims 1 to 3, wherein a space formed by the central convex member and the partition wall forming the cell is a space in which a display medium is arranged. panel.   The center convex member is provided in the center of a cell on a back side substrate, and a space in which a display medium is disposed is formed between the central convex member and all the partition walls forming the cell. Item 5. The information display panel according to any one of Items 1 to 4. The height Ht of the central convex member is relative to the distance Hw between the substrates.
Hw / 4 ≦ Ht ≦ Hw / 2
The information display panel according to claim 1, wherein: In the space where the display medium is arranged, the distance Wt between the side surface portion of the central convex member and the partition wall is an average particle diameter d (0.5) of particles constituting the display medium.
3 × d (0.5) ≦ Wt
The information display panel according to claim 1, wherein: The height Ht of the central convex member and the distance Hw between the substrates are relative to the average particle diameter d (0.5) of the particles constituting the display medium.
3 × d (0.5) ≦ Hw
2 × d (0.5) <Hw−Ht
The information display panel according to claim 1, wherein:

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