JP2010197649A - Image display medium and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium capable of effectively inhibiting generation of an image defect when writing is performed with a writing material on a display surface of the image display medium, and to provide an image display device including the image display medium. <P>SOLUTION: The image display medium is provided with: a display-side substrate 1 on which a display-side electrode 2 is formed and an image is displayed; a back-side substrate 3 which is arranged so as to face the display-side substrate 1 and on which a back-side electrode 4 is formed; a spacer 5 which divides a space between the display-side substrate 1 and the back-side substrate 3 in the row direction and the column direction; a cell 6 which is formed by the spacer 5 and inside of which migration solution 7 is encapsulated; floating particles 8 floating in the migration solution 7 inside the cell 6; migration particles 9 which migrate in the direction going to the display-side substrate 1 or the direction going to the back-side substrate 3 in the migration solution 7 according to potential difference between the display-side electrode 2 and the back-side electrode 4; a cylindrical member 10 which is provided in the cell 6 and supports the floating particles 8 from the side of the back-side substrate 8; and a migration particle storage space 11. The image display device having the image display medium is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image display medium and an image display device.

An electrophoretic display having a well-defined shape, size and aspect ratio cell, the cell having a convex substructure inside and charged in a dielectric solution Some are filled with pigment particles (Patent Document 1)
JP 2005-502087 A

  In an image display medium such as electronic paper, a memo or the like may be written on a display surface, which is a surface of a display-side substrate on which an image is displayed, with various writing tools such as a ballpoint pen.

  In this case, it is not preferable that the display-side substrate is greatly deformed by the writing pressure applied from the writing tool applied to the display surface, and the migrating particles attached to the inner surface of the display-side substrate are peeled off to cause an image defect.

  It is an object of the present invention to provide an image display medium capable of effectively suppressing the occurrence of image defects when writing on the display surface of the image display medium with a writing tool, and an image display device including the image display medium.

  The invention according to claim 1 is a transparent substrate on which a display-side electrode, which is a transparent electrode, is formed, the display-side substrate on which an image is displayed, and an array arranged so as to face the display-side substrate. A rear substrate on which side electrodes are formed, a spacer that partitions a space between the display substrate and the rear substrate in a row direction and a column direction, and the space is partitioned in the row direction and the column direction by the spacer. And a cell in which an electrophoretic liquid, which is an electrically insulating liquid, is sealed, and particles having a predetermined color, and floating particles that float in the electrophoretic liquid inside the cell And having a particle size smaller than that of the suspended particles, having a color different from that of the suspended particles, and the inside of the electrophoresis solution according to the potential difference between the display side electrode and the back side electrode. Direction toward the board Alternatively, migrating particles that migrate in a direction toward the rear substrate, and floating particles that are provided on the rear substrate side at an interval shorter than 1/10 of the average particle diameter of the floating particles and do not contact the display-side substrate. And an image display medium comprising a support member.

  Invention of Claim 2 is the image display medium of Claim 1, Between the space | interval L of the said floating particle support member and a display side board | substrate, and the average particle diameter d of the said floating particle,

                              d <L <3d

The interval L is set so that the above relationship is established.

  A third aspect of the present invention relates to the image display medium according to the first or second aspect, wherein a surface of the floating particle support member facing the display side substrate is colored in the same color as the floating particles.

  According to a fourth aspect of the present invention, in the image display medium according to any one of the first to third aspects, the floating particle support member is directed from the back side substrate side surface of the cell toward the display side substrate. The columnar member is erected, and the migrating particle accommodation space is a gap formed between adjacent columnar members.

  A fifth aspect of the present invention is the image display medium according to any one of the first to third aspects, wherein the floating particle support member is provided substantially in parallel to the display-side substrate. The electrophoretic particle accommodation space is an opening formed in the plate-like member at a predetermined interval.

  A sixth aspect of the present invention relates to the image display medium according to any one of the first to fifth aspects, wherein the floating particles have a white color and the migrating particles have a chromatic color or a black color.

  The invention according to claim 7 is the image display medium according to claim 6, wherein the migrating particles are particles colored yellow (Y), particles colored magenta (M), and cyan (C). To those containing colored particles.

  The invention according to claim 8 relates to the image display medium according to claim 7, wherein the migrating particles further include particles colored in black (K).

  The invention according to claim 9 is the image display medium according to any one of claims 1 to 8, wherein the display-side electrode is formed on the entire surface of the display-side substrate, and the back-side electrode is a two-dimensional matrix. It is related with what is formed in the shape.

  The invention according to claim 10 is the image display medium according to any one of claims 1 to 8, wherein the display side electrode is a linear electrode formed at a predetermined pitch, and the back side electrode is The present invention relates to a linear electrode formed at a predetermined pitch so as to intersect the display side electrode in a plan view.

  An invention according to an eleventh aspect is the image display medium according to any one of the first to tenth aspects, and a voltage application circuit that applies a predetermined voltage to the display-side electrode and the back-side electrode of the image display medium. And an image display apparatus.

  According to the first aspect of the present invention, there is provided an image display medium capable of effectively suppressing the occurrence of image defects when writing with a writing instrument on the display surface which is the surface of the display side substrate.

  According to the invention of claim 2, unlike the image display medium in which the distance L between the suspended particle support member and the display side substrate is equal to or less than the average particle diameter d of the suspended particles, the floating is suspended in a state where the writing pressure by the writing instrument is not applied. An image when writing is performed on a display surface with a writing tool as compared with an image display medium in which the movement of particles is not hindered by the suspended particle support member and the interval L is three times or more the average particle diameter d. An image display medium that can effectively suppress the occurrence of defects is provided.

  According to the invention of claim 3, since the suspended particles and the suspended particle support member are the same color, the suspended particle support member is inconspicuous and an image display medium capable of natural image display is provided.

  According to the invention of claim 4, when an image is displayed on the display surface and when it is not displayed as compared with an image display medium having a plate-like member having an opening for accommodating migrating particles as a floating particle support member. An image display medium having a large contrast difference is provided.

  According to the invention of claim 5, there is provided an image display medium that is easier to manufacture than an image display medium having a columnar member as a suspended particle support member.

  According to the sixth aspect of the present invention, there is provided an image display medium that has a white display surface and is capable of natural image display.

  According to invention of Claim 7, the image display medium which can display a color image is provided.

  According to the eighth aspect of the present invention, an image display medium in which black is brighter than an image display medium that does not include particles colored in black (K) as migrating particles is provided.

  According to the ninth aspect of the present invention, there is provided an image display medium capable of simplifying the voltage application circuit for driving the electrodes as compared with the image display medium in which the display-side electrode and the back-side electrode are formed in a line shape. .

  According to the invention of claim 10, the display-side electrode and the back-side electrode are manufactured as compared with the image display medium in which the display-side electrode is formed on the entire surface of the display-side substrate and the back-side electrode is formed in a two-dimensional matrix. Is provided.

  According to the eleventh aspect of the present invention, it is possible to more effectively prevent display defects when the writing pressure of the writing instrument is applied to the image display medium as compared with an image display apparatus having an image display medium that does not have a suspended particle support member. An image display device is provided.

FIG. 1 is a cross-sectional view in the thickness direction showing the configuration of the electronic paper according to the first embodiment. FIG. 2 is a perspective view illustrating a configuration of the electronic paper according to the first embodiment. FIG. 3 is a perspective view illustrating a configuration of another example of the electronic paper according to the first exemplary embodiment. FIG. 4 is a perspective view in the thickness direction showing the configuration of still another example of the electronic paper according to the first exemplary embodiment. FIG. 5 is an explanatory diagram illustrating an example in which cylindrical members are arranged in a grid pattern or a staggered pattern in a plan view in the electronic paper according to the first embodiment. FIG. 6 is an explanatory diagram showing the relationship between the size of the gap between the cylindrical members and the average particle size of the suspended particles in the electronic paper according to the first embodiment. FIG. 7 is a cross-sectional view in the thickness direction showing a state in which the pressure of the pen tip of the ballpoint pen is applied to the display surface in the electronic paper according to the first embodiment. FIG. 8 is a cross-sectional view in the thickness direction showing a state in which the pressure at the tip of the ballpoint pen is applied to the display surface in the electronic paper having no cylindrical member.

1. Embodiment 1

1-1 Configuration

  Hereinafter, electronic paper as an example of the image display medium of the present invention will be described.

  As shown in FIGS. 1 to 3, the electronic paper 100 according to the first embodiment includes a display-side substrate 1 that is a transparent substrate in which a display-side electrode 2 that is a transparent electrode is formed on the entire lower surface, and a back side. A back substrate 3 on which electrodes 4 are formed, and a column-direction and row-direction spacer 5 that divides a space between the display-side substrate 1 and the back-side substrate 3 into a plurality of cells 6 in the row direction and the column direction. Prepare.

  Each cell 6 is filled with an electrophoretic liquid 7 which is an electrically insulating transparent liquid. The electrophoretic liquid 7 has a white particle-colored floating particle 8 and yellow (Y), magenta (M), or cyan (C) color, and has a particle size smaller than that of the floating particle 8. Electrophoretic particles 9 (9Y, 9M) that migrate in the electrophoretic liquid 7 in the direction toward the display-side substrate 1 or in the direction toward the back-side substrate 3 according to the potential difference between the display-side electrode 2 and the back-side electrode 4. 9C) are floating. In FIG. 1 and the following figures, the migrating particles 9M are located on the display substrate 1 side and a magenta image is displayed.

  Inside the cell 6, a columnar member 10 as a suspended particle support member is erected from the surface on the back side substrate 3 side toward the display side substrate 1. As a result, a gap 11 is formed. The entire cylindrical member 10 is colored white.

  The cylindrical members 10 may be arranged in a grid pattern in the row direction and the column direction in a plan view as shown in FIG. 5A, and in a plan view as shown in FIG. It may be arranged in a zigzag pattern. However, when the columnar members 10 are arranged in a grid pattern, as shown in FIG. 6A, the diameter R of the circles in contact with the four columnar members 10 adjacent to each other is the columnar member. When 10 are arranged in a staggered pattern, as shown in FIG. 6B, the diameter R of the circle in contact with the three adjacent cylindrical members 10 is 1 of the average particle diameter d of the suspended particles 8. It is necessary to make it smaller than / 10. Here, the average particle diameter d of the suspended particles 8 can be obtained as a simple average of the particle diameters of the group of suspended particles 8 enclosed in all the cells 6. In order to make the diameter R of the circle in contact with the three cylindrical members 10 adjacent to each other smaller than 1/10 of the average particle diameter d of the suspended particles 8, as described later, If the average particle size is preferably 10 times or more the average particle size of the migrating particles 9, and the interval is 1/10 or less of the average particle size of the floating particles 8, the floating particles 8 of the cylindrical member 10 This is because the floating particles 9 do not enter between the cylindrical members 10 without any problem.

  Further, the distance L between the top surface of the columnar member 10 and the display side substrate 1 is as shown in FIG.

                              d <L <3d

The relationship is established.

  In addition to the columnar member 10, the suspended particle support member includes a prismatic member, a hexagonal columnar member, a triangular columnar member, and the like. Further, as shown in FIG. 4, a plate-like member 20 provided with migrating particle accommodation holes 21 as a migrating particle accommodation space at a predetermined pitch is also included in the suspended particle support member in the present invention. In FIG. 4, the electrophoretic liquid 7, the floating particles 8, and the electrophoretic particles 9 are omitted.

  Hereinafter, each part of the electronic paper 100 will be described in detail.

  The display side substrate 1 is made of a transparent material.

  Examples of the transparent material include transparent resins such as acrylic resin, polycarbonate resin, polyethylene terephthalate resin, polyethylene sulfide resin (PES), polysulfone resin, and polyethersulfone resin.

  The display-side electrode 2 is formed of a transparent conductive oxide such as indium-tin oxide (ITO) and indium-zircon oxide (IZO). The display-side electrode 2 may be provided on the entire back surface of the display-side substrate 1 as shown in FIGS. 1 and 2, and is a line-like electrode provided at a constant pitch as shown in FIG. May be.

  The back side substrate 3 may be formed of the same transparent material as that of the display side substrate 1, or may be formed of an opaque material such as ABS resin or glass epoxy resin.

  The back side electrode 4 may be formed of a transparent conductive oxide such as ITO or IZO as with the display side electrode 2, or may be formed of a metal material such as a gold foil or a copper foil. However, as shown in FIGS. 1 and 2, when the display-side electrode 2 is provided on the entire back surface of the display-side substrate 1, the back-side electrode 4 is formed in a two-dimensional matrix, as shown in FIG. As described above, when the display-side electrode 2 is a line-shaped electrode formed at a constant pitch, the back-side electrode 4 is a line-shaped electrode formed so as to be orthogonal to the display-side electrode 2.

  The shape of the spacer 5 is usually a grid shape in the row direction and the column direction as shown in FIGS. 3 and 4, but may be a honeycomb shape. When the spacer 5 has a honeycomb shape, the planar shape of the cell 6 is a regular hexagon.

  The height of the spacer 5 is not particularly limited, but about 10 to 100 μm is preferable from the viewpoint of flexibility of the electronic paper 100. The width is preferably about 5 to 20 μm. Further, the length of one side of the cell 6 is preferably about 0.1 to 1 mm.

  The spacer 5 may be formed by a photolithography method using a photosensitive resin, or may be cured by pressing a concave mold against a photocurable liquid resin or a photocurable film. The summer plastic resin film may be formed by heating and softening and pressing the concave mold to cool and solidify, or by pressing the thermosetting resin and thermosetting the thermosetting resin. Further, a predetermined pattern may be printed by screen printing or ink jet printing with a transparent liquid resin, and cured by an appropriate means such as heat, light, or electron beam.

  The spacer 5 does not necessarily need to be transparent, and may be black, gray, or white achromatic color.

  The electrophoretic liquid 7 is not particularly limited as long as it is an electrically insulating liquid. Usually, silicone oil, knitted silicone oil, fluorine oil, isoparaffin, or the like is used. The viscosity is preferably 1 and about 100 mPa · s. A surfactant may be added to the electrophoretic liquid 7 in order to improve dispersion of the floating particles 8 and the electrophoretic particles 9.

  As the floating particles 8, usually white particles having a particle diameter of about 0.1 to 20 μm are used. The suspended particles 8 are particles colored in a color different from that of white or migrating particles, and may form a porous body in a state of being suspended in the migrating solution, fixed in a packed state, or fixed to each other. Good. The migrating particles 9 migrate between the transparent electrodes 2 and the pixel electrodes 4 through the floating particles 8 and display an image according to predetermined pixel data.

  As the floating particles 8, for example, particles formed from a thermoplastic resin such as an acrylic resin or a styrene resin are used.

  The suspended particles 8 may be configured such that particles are arranged at least in the plate surface direction of the surface substrate 1 in the region between the surface substrate 1 and the back substrate 3, as shown in FIGS. 1 and 2. It is desirable that the entire area between the front substrate 1 and the rear substrate 3 is filled with a density such that the suspended particles 8 cannot move relative to each other.

  The average particle diameter of the floating particles 8 is not particularly limited, but when the aggregate of the floating particles 8 is arranged in a region between the front substrate 1 and the rear substrate 3, It is preferable to have an average particle size such that there is an interval that allows the migrating particles 9 to pass therethrough.

  For this reason, the average particle size of the floating particles 8 is preferably 10 times or more, and preferably 25 times or more that of the migrating particles 9. If the average particle size of the floating particles 8 is less than 10 times the average particle size of the migrating particles 9, it is difficult for the migrating particles 9 to pass between the floating particles 8 and the particles. May be difficult. The upper limit of the average particle diameter of the suspended particles 8 is not particularly limited, but is smaller than the distance between the front substrate 1 and the rear substrate 3.

  As an example, when the average particle diameter of the migrating particles 9 is 0.01 μm to 1 μm as will be described later, it is desirable that the average particle diameter of the floating particles 8 is in the range of 1 μm to 20 μm.

  The color of the floating particles 8 is not particularly limited as long as it is different from the color of the migrating particles 9. When the floating particles 8 are colored, a known coloring agent such as a coloring agent used when the dispersion medium 26 is colored may be contained in the material constituting the floating particles 8. Specifically, for example, to make the color of the suspended particles 8 white, a white material may be fixed to the surface of the suspended particles 8. As this white material, white pigments such as titanium dioxide, barium titanate, barium sulfate, and calcium carbonate can be used.

  As the migrating particles 9, fine particles colored in Y, M, or C color are used. Furthermore, fine particles colored black (K) can also be used. The diameter of the migrating particles 9 needs to be smaller than the average particle diameter d of the floating particles 8 and is preferably 1 μm or less, and particularly preferably about 10 to 200 nm.

  As the migrating particles 9, fine particles obtained by suspension polymerization of MMA or the like in a medium in which pigments or colorants of these colors are dispersed are preferable because of their high sphericity. Toner particles and wax particles in which the above pigment is dispersed are also used. In addition, metal fine particles exhibiting coloration by plasmon resonance are also used.

1-2 Action

  Hereinafter, the operation of the electronic paper according to the first embodiment will be described.

  The display side electrode 2 of the display side substrate 1 and the back side electrode 4 of the back side substrate 3 are connected to a drive circuit through a driver, the potential of the display side electrode 2 is set to 0 V, and the back side electrode 4 is connected. When an arbitrary voltage can be sensitized, the voltage of the back surface side electrode 4 is changed so that any one or two or more of the migrating particles 9Y, 9M, and 9C are displayed on the display substrate 1 side with respect to the floating particles 8. It is possible to perform arbitrary color display by moving to.

  Here, as shown in FIGS. 7 and 8, when pressure from a pen tip such as a ballpoint pen is applied to the display surface of the electronic paper 100, a cylindrical member 10 such as the one shown in FIG. In the electronic paper in which the suspended particle support member is not provided, the migrating particles 9M located on the display side substrate 1 of the cell 6 move to the lower side of the suspended particles 8 by the pressure applied to the display side substrate 1 and display. The area where the pressure is applied disappears. On the other hand, in the electronic paper 100 according to the first embodiment, as shown in FIG. 7, since the downward movement of the suspended particles 8 is hindered by the columnar member 10, the movement of the migrating particles 9M is also hindered. It is done. This prevents display defects in the portion where the writing pressure is applied by a writing instrument such as a ballpoint pen.

DESCRIPTION OF SYMBOLS 1 Display side substrate 2 Display side electrode 3 Back surface side substrate 4 Back surface side electrode 5 Spacer 6 Cell 7 Electrophoretic liquid 8 Floating particle 9 Electrophoretic particle 9Y Electrophoretic particle 9M Electrophoretic particle 9C Electrophoretic particle 10 Columnar member 11 Gap part 20 Plate-shaped member 21 Electrophoretic particle accommodation hole 100 Electronic paper

Claims (11)

A transparent substrate on which a display-side electrode that is a transparent electrode is formed, and a display-side substrate on which an image is displayed;
A back side substrate arranged to face the display side substrate and having a back side electrode formed thereon;
A spacer for partitioning a space between the display side substrate and the back side substrate in a row direction and a column direction;
A cell in which the space is partitioned and formed in the row direction and the column direction by the spacer, and an electrophoretic liquid that is an electrically insulating liquid is sealed therein;
Particles having a predetermined color, and floating particles floating in the electrophoresis solution inside the cell;
The particle size is smaller than that of the suspended particles, has a color different from that of the suspended particles, and the electrophoretic liquid is applied to the display side substrate according to a potential difference between the display side electrode and the back side electrode. Migrating particles that migrate in the direction toward or toward the back substrate;
A floating particle support member provided on the back substrate side at an interval shorter than 1/10 of the average particle diameter of the floating particles, and not in contact with the display-side substrate;
An image display medium comprising: Between the gap L between the floating particle support member and the display side substrate and the average particle diameter d of the floating particles,
d <L <3d
The image display medium according to claim 1, wherein an interval L is set so that the relationship is established.   3. The image display medium according to claim 1, wherein a surface of the floating particle supporting member facing the display side substrate is colored in the same color as the floating particles.   The floating particle support member is a columnar member erected from the back side substrate side surface of the cell toward the display side substrate, and the migrating particle accommodation space is a gap formed between adjacent columnar members The image display medium according to any one of claims 1 to 3.   The floating particle support member is a plate-like member provided substantially parallel to the display-side substrate, and the migrating particle accommodation space is an opening provided in the plate-like member at a predetermined interval. The image display medium according to any one of claims 1 to 3.   The image display medium according to claim 1, wherein the suspended particles have a white color, and the migrating particles have a chromatic color or a black color.   The image display medium according to claim 6, wherein the migrating particles include particles colored yellow (Y), particles colored magenta (M), and particles colored cyan (C).   The image display medium according to claim 7, wherein the migrating particles further include particles colored in black (K).   The image display medium according to claim 1, wherein the display-side electrode is formed on the entire surface of the display-side substrate, and the back-side electrode is formed in a two-dimensional matrix.   2. The display-side electrode is a linear electrode formed at a predetermined pitch, and the back-side electrode is a linear electrode formed at a predetermined pitch so as to intersect the display-side electrode in plan view. The image display medium of any one of -8.   An image display device comprising: the image display medium according to claim 1; and a voltage application circuit that applies a predetermined voltage to a display-side electrode and a back-side electrode of the image display medium.

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