JP2008176213A - Writing device for information display sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing device that allows manual writing on an information display sheet, requires no large device for writing and erasing and shows excellent portability. <P>SOLUTION: The writing device is characterized in that: a front transparent panel is disposed in a visible side; a front side transparent conductive film including a solid electrode (or a small area electrode) and metal thin lines is disposed on the front transparent panel; a back panel is disposed in the opposite side to the visible side; a back side conductive film is disposed on the back panel; a rewritable information display sheet is inserted into the space between the front transparent panel and the back panel; a space is provided between the front transparent panel and the inserted information display sheet; a voltage that generates an electric field weaker than the driving threshold of the display medium is applied between the front side transparent conductive film and the back side conductive film; a writing tool is pressed to the front transparent panel to bend, reducing the distance between the opposing conductive films; and thereby, the electric field generated between the conductive films rises over the driving threshold, which moves the display medium to perform writing display. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention encloses at least one type of display medium having optical reflectivity and chargeability composed of at least one type of particles between two opposing substrates, at least one of which is transparent, in the display medium. Rewriteable information display sheet writing device that can be written and rewritten many times by handwriting on an information display sheet that displays information such as images by moving the display medium by applying an electric field It is.

  As an information display device that replaces a liquid crystal display device (LCD), an information display device using techniques such as an electrophoretic method, an electrochromic method, a thermal method, and a two-color particle rotation method has been proposed.

  Also, at least one kind of display medium having optical reflectivity and chargeability composed of at least one kind of particles is contained in a cell formed by a partition between two opposing substrates, at least one of which is transparent. An information display panel that displays information such as an image by moving the display medium by enclosing and applying an electric field to the display medium is known.

As a prior art of a rewritable reversible image display panel, at least one is formed between two sheets having light transmittance and two sheets, and one or more surrounded by a partition wall Developer containing cells and a dry developer contained in each cell. The dry developer has at least two types of triboelectric charging having different charging polarities and different optical reflection densities. There is provided a reversible image display panel including dry developing particles having the property. Further, as a prior art of the reversible image display method using this reversible image display panel, the development particles contained in each cell are made to correspond to the image to be displayed on the development particles in a state of frictional charging. There has been provided a method of displaying an image by moving the developing particles by forming a predetermined electrostatic field for each pixel (for example, Patent Document 1).
JP 2001-290179 A

In the above-described rewritable reversible image display panel, images are displayed and erased by setting a rewritable reversible image display medium in a dedicated image forming apparatus. The image is limited to the image based on the electronic data input to the image forming apparatus, and information such as an image written by hand cannot be displayed or deleted.
In addition, since the dedicated image display device is large, it is inconvenient for use in operations such as rewriting display with the image display device at hand, and is not suitable for carrying.

  The object of the present invention is to solve the above-mentioned problems, and can be written and displayed on an information display sheet, does not require a large device for writing and erasing, and is excellent in portability. To provide an apparatus.

The information display sheet writing device of the present invention comprises at least one or more display media having at least one kind of particles between two opposing substrates, at least one of which is transparent, and having optical reflectivity and chargeability. In a writing device that includes an information display sheet that displays and displays information such as an image by moving the display medium by applying an electric field to the display medium.
The information display sheet is detachable from the writing device,
Provide a writing device front transparent panel on the viewing side of the writing device,
A front side transparent conductive film is disposed on the writing device front transparent panel,
The front-side transparent conductive film is constituted by a solid electrode and a mesh-like metal thin wire that is in contact with the upper and lower surfaces of the solid electrode or embedded in the solid electrode, or a small area electrode group and the small electrode It consists of fine mesh metal wires in contact with all of the area electrode groups,
A writing device rear panel is provided on the opposite side of the writing device from the viewing side,
A back side conductive film is disposed on the writing device back panel,
Inserting the information display sheet into the space between the writing device front transparent panel and the writing device back panel;
A space is provided between the writing device front transparent panel and the inserted information display sheet,
A voltage is applied between the front transparent conductive film and the rear conductive film to form an electric field that is smaller than a drive threshold of an electric field driven by the display medium,
Press the writing device against the front transparent panel of the writing device and deflect it.
By reducing the distance between the front-side transparent conductive film and the back-side conductive film, the electric field formed between the two conductive films becomes equal to or greater than the driving threshold.
The display medium is moved, and writing display can be performed.

  Here, the solid electrode means a continuous conductive film, and the small area electrode group means a large number of continuous electrodes arranged with a gap.

  Further, in the information display sheet writing device of the present invention, the solid electrode or the small area electrode group is formed so as to cover the mesh metal thin wire, or the small area electrode group is the mesh metal thin wire. Arranged such that the small-area electrode group is a triangle, a quadrangle, a circle, a hexagon, or a line shape, or the mesh shape of the mesh metal fine wire is a rectangle, or It is characterized by being a triangle.

According to the present invention, at least one display medium having at least one kind of particles and having optical reflectance and chargeability is disposed between two opposing substrates, at least one of which is transparent, and the display medium. In a writing device that includes an information display sheet that displays information such as an image by moving a display medium by applying an electric field to the display device,
The information display sheet is detachable from the writing device,
Provide a writing device front transparent panel on the viewing side of the writing device,
A front side transparent conductive film is disposed on the writing device front transparent panel,
The front-side transparent conductive film is constituted by a solid electrode and a mesh-like metal thin wire that is in contact with the upper and lower surfaces of the solid electrode or embedded in the solid electrode, or a small area electrode group and the small electrode It consists of fine mesh metal wires in contact with all of the area electrode groups,
A writing device rear panel is provided on the opposite side of the writing device from the viewing side,
A back side conductive film is disposed on the writing device back panel,
Inserting the information display sheet into the space between the writing device front transparent panel and the writing device back panel;
A space is provided between the writing device front transparent panel and the inserted information display sheet,
A voltage is applied between the front transparent conductive film and the rear conductive film to form an electric field that is smaller than a drive threshold of an electric field driven by the display medium,
Press the writing device against the front transparent panel of the writing device and deflect it.
By reducing the distance between the front-side transparent conductive film and the back-side conductive film, the electric field formed between the two conductive films becomes equal to or greater than the driving threshold.
By moving the display medium and performing writing display,
An object of the present invention is to provide a writing device for an information display sheet which is capable of handwritten writing display on an information display sheet, does not require a large-scale device for writing or erasing, and has excellent portability.

  First, a basic configuration of an information display sheet that is inserted into the writing device of the present invention and displays information will be described. In the information display sheet, an electric field is applied to a display medium having optical reflectivity and chargeability sealed between two opposing substrates. 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 sheet so that the display medium can move uniformly and maintain stability when rewriting the display repeatedly or when displaying the display information continuously. Here, as the force applied to the particles constituting the display medium, in addition to the force attracting each other by the Coulomb force between the particles, an electric mirror image force between the electrode and the substrate, an intermolecular force, a liquid cross-linking force, gravity and the like can be considered.

An example of the information display sheet used in the present invention will be described below.
In the example shown in FIGS. 1A and 1B, at least two types of display media 3 (here, the display white particles 3Wa) having different optical reflectance and charging characteristics composed of at least one type of particles are used. The white display medium 3W composed of the particle group and the black display medium 3B composed of the display black particle 3Ba) are moved perpendicularly to the substrates 1 and 2 according to the electric field applied from the outside of the substrates 1 and 2. The black display medium 3B is visually recognized by the observer and black display is performed, or the white display medium 3W is visually recognized by the observer and white display is performed. In the example shown in FIG. 1B, in addition to the example shown in FIG. 1A, a partition 4 is provided between the substrates 1 and 2, for example, in the form of a lattice to form a cell. In addition, in FIG. 1B, the partition in front is omitted. As the cell, a microcapsule in which the display medium is sealed with an insulating liquid is used, and an information display sheet having a configuration in which the microcapsule is disposed between the substrates can be used.

  The above description is similarly applied to the case where the white display medium 3W including the particle group is replaced with the white display medium including the powder fluid and the black display medium 3B including the particle group is replaced with the black display medium including the powder fluid. I can do it. The powder fluid will be described later. Also, the color combination is not limited to black and white, and various color (optical reflectance) combinations are possible.

2 (a) to 2 (c) are diagrams for explaining an information display sheet writing apparatus according to the present invention.
FIG. 2A is a schematic diagram showing a state in which an information display sheet for writing display is mounted on a writing device. The information display sheet 21 can be removed, and is inserted into a writing device when writing, and is removed and used when writing is completed. The writing device is composed of a writing device front transparent panel, an information display sheet 21, and a writing device rear panel, and an information display sheet insertion space is provided between the writing device front transparent panel and the writing device rear panel. Even after the information display sheet 21 is inserted, a space remains between the front transparent panel of the writing device and the information display sheet 21. The writing device front transparent panel constitutes a front-side flexible transparent substrate 11 and a front-side transparent conductive film 12, and the writing device rear panel constitutes a back-side conductive film 17 and a back-side substrate 18.
2B shows a state where the information display sheet is inserted and attached to the writing device, and FIG. 2C shows a state where the information display sheet is inserted and attached to the writing device. The information display sheet 21 for writing display has a structure in which a display medium composed of color particles that can be driven by an electric field is sealed between at least one transparent substrate and the other opposing substrate. The information written by handwriting is displayed by moving (driving) by applying an electric field to.

FIGS. 3A to 3D are diagrams for further explaining the information display sheet writing apparatus of the present invention, in which a negatively charged white display medium and a positively charged black display medium are formed of partition walls. The state that the information display sheet enclosed in the inside is mounted on the writing device is shown. The writing device front transparent panel includes a front side flexible transparent substrate 11, a front side transparent conductive film 12, and a front side protective layer 13, and the writing device rear panel includes a back side protective layer 16 and a back side. The conductive film 17 and the back side substrate 18 are used. The front transparent conductive film 12 includes a thin metal wire, which will be described below.
The protective layer is provided to protect the conductive film formed on the panel of the writing device from frictional damage when the information display sheet is attached / detached, and may be provided on the front transparent panel of the writing device having the front-side transparent conductive film 12. Preferably, it needs to be further transparent. Since the back-side conductive film 17 of the writing device back panel may be opaque, the protective layer may be omitted if a material with little frictional damage such as metal is selected.
A gap between the lower surface of the writing device front transparent panel and the upper surface of the writing device rear panel is an information display sheet insertion space. This information display sheet insertion space has an interval of 1.2 to 2 times, preferably 1.5 to 2 times the thickness of the information display sheet. If the interval is less than 1.2 times, the deformation amount of the conductive film of the transparent panel on the front surface of the writing device may not be sufficiently obtained, and an electric field exceeding the driving threshold may not be obtained. There is an inconvenience that the amount of deformation of the conductive film of the front transparent panel becomes too large, the conductive film is broken, or the metal fine wire is broken, and the function as the conductive film is not performed.
The size of the writing device in the horizontal direction of the panel may be such that the information display sheet can be inserted and mounted in the conductive film arrangement area.
3 (b) to 3 (d) show how the writing device 20 is pressed against the transparent front panel of the writing device to move the display medium in the information display sheet. FIG. 3 (b) shows the state before writing, FIG. FIG. 3 (d) shows a state after writing while FIG. 3 (d) shows the state after writing.
A potential difference (voltage) is applied between the front-side transparent conductive film 12 and the back-side conductive film 17 (between the conductive film) so that an electric field smaller than a threshold value that is an electric field strength driven by the display medium is applied in advance. Keep it. When the writing device 20 such as a pen is pressed against the transparent front panel of the writing device, the distance between the conductive films is reduced due to the deformation of the transparent front panel of the writing device, the electric field formed between the conductive films is increased, and the display medium is driven. The electric field exceeds the threshold value, the display medium is driven, and display is performed.
As shown in FIG. 3 (c), the writer 20 is pressed against the front transparent panel of the writer to deform it in the direction of the information display sheet, the distance between the conductive film is reduced, and the positively charged black display medium is written. Move to the front panel of the device. Even if a crack occurs in the solid electrode, it is directly connected by the fine metal wire, so that the function does not deteriorate.
When the information display sheet is taken out from the writing device after the writing is completed, the electric field application state is released, but the display medium once moved maintains the state of being attached to the inside of the panel substrate (display memory property). The written information continues to be displayed as it is.

In the present invention, the front transparent conductive film 12 disposed on the front transparent panel of the writing device is a mesh-like fine metal wire that is in contact with a solid electrode or a small area electrode group and the upper and lower surfaces of these electrodes or is embedded in and in contact with these electrodes. It consists of. As a result, the deformation of the writing device front panel is caused by a thin metal wire portion connecting the solid electrodes or the small area electrodes, and by using a metal having excellent deformability, each solid electrode or The function as an electrode can be maintained for a long time without disconnection between small area electrodes. The front transparent conductive film 12 disposed on the front transparent panel of the writing device can be formed by arranging metal fine wires in a lattice shape or a mesh shape, and can be combined with a transparent solid electrode. In this case, it becomes a configuration in which a solid electrode that is uniformly continuous and a fine metal wire are combined, but even if the solid electrode is cracked or cracked, the solid electrode small pieces constitute a small area electrode. Thus, since the conductive state is maintained through the fine metal wires, the function as an electrode can be maintained for a long time.
The back side conductive film 17 is formed of a so-called solid electrode having a conductive film on the entire surface. Since this electrode does not need to be transparent and does not need to have flexibility, it can be selected from a wide range of conductive materials.
The front-side transparent conductive film 12 and the back-side conductive film 17 may be arranged so as to face each other as small-area electrodes having a pixel size, and each small-area electrode may have an independent wiring made of fine metal wires.

Although the metal material is excellent in conductivity and flexibility, it is not transparent, so there is a problem in arranging it on the writing device front transparent panel side, but it is 50 μm or less (preferably 1 μm to 50 μm, more preferably It turned out that there is no problem in visibility by setting it as the thin wire of the width | variety of 1 micrometer-20 micrometers, More preferably, 1 micrometer-10 micrometers.
The thickness of the thin metal wire and the thickness of the solid electrode (including the case of a small area electrode) are formed in the range of 10 nm to 1000 nm (preferably 10 nm to 400 nm), and may be the same thickness or different thicknesses. From the viewpoint of flexibility, it is preferable to increase the thickness of the fine metal wire.
The space | interval which arrange | positions a metal fine wire in a matrix form is formed in the range of 50 micrometers-500 micrometers (preferably 100 micrometers-500 micrometers) so that visibility may not be disturbed. It is preferable that the distances are not strictly equal so as not to hinder visibility due to interference.
As a material for the metal fine wire, a metal material having electrical conductivity and flexibility such as copper, aluminum, gold, and silver can be used.

  4 (a) to 4 (d) are production examples of a mesh-like fine metal wire and a transparent solid electrode of a front-side transparent conductive film provided in the writing device front transparent panel of the present invention. As shown in FIGS. 4 (a) and 4 (b), the mesh shape of the mesh metal fine wires 23 is arranged in a quadrangular shape, and as shown in FIGS. 4 (c) and 4 (d), the solid electrode 24 is mesh metal mesh fine wires. 23, and the solid electrode 24 is divided as shown in FIGS. 4E and 4F to form a rectangular small-area electrode 25. 4 (a), (c), and (e) are front views, and FIGS. 4 (b), (d), and (f) are AA in FIGS. 4 (a), (c), and (e), respectively. It is sectional drawing in a position. The front side transparent conductive film may be used as it is as shown in FIGS. 4C and 4D, or the solid electrode 24 is divided as shown in FIGS. 4E and 4F. However, it may be used as the rectangular small area electrode 25.

  5 (a) to 5 (f) are other examples of manufacturing a mesh-like fine metal wire and a transparent solid electrode of the front transparent conductive film provided on the transparent front panel of the writing device of the present invention. As shown in FIGS. 5 (a) and 5 (b), the mesh shape of the mesh metal thin wires 23 is arranged in a square, and as shown in FIGS. 5 (c) and 5 (d), the solid electrode 24 is arranged as a mesh metal thin wire. The solid electrode 24 is arranged between the meshes 23 so as to be in contact with the fine metal wire, and the solid electrode 24 is divided as shown in FIGS. 5 (a), (c), and (e) are front views, and FIGS. 5 (b), (d), and (f) are AA in FIGS. 5 (a), (c), and (e), respectively. It is sectional drawing in a position. The front side transparent conductive film may be used as it is as shown in FIGS. 5C and 5D, or the solid electrode 24 may be divided as shown in FIGS. 5E and 5F. However, it may be used as the rectangular small area electrode 25.

  FIGS. 6A and 6B are arrangement examples of the front-side transparent conductive film and the fine metal wires used in the present invention. FIG. 6A shows the mesh shape of the mesh metal fine wire 23 in a square shape, and FIG. 6B shows the mesh shape of the mesh metal fine wire 23 in a triangle shape, and touches the upper and lower surfaces thereof. A solid electrode is formed so as to be embedded inside and in contact therewith. Even if cracks or cracks occur in the solid electrode, the electrical conductivity is maintained by the fine metal wires, so that the function as the conductive film is maintained.

7A to 7F are other arrangement examples of the front side transparent conductive film and the fine metal wires used in the present invention. FIG. 7A shows an example in which the small area electrode 25 is arranged as a square small area electrode, and FIG. 7B is an example where the small area electrode 25 is arranged as a circular small area electrode in a grid pattern. FIG. 7C shows an example in which the small area electrode 25 is arranged in a line shape as a line type small area electrode. FIG. 7D shows an example in which the small area electrode 25 is a rectangular small area electrode and a line small area electrode. FIG. 7E shows the small area electrode 25 as a circular small area electrode, and FIG. 7F shows the small area electrode 25 as a hexagonal small area electrode, which are arranged at the intersections of thin metal wires forming a triangular mesh shape. This is an example.
Of these, it is preferable to increase the flexibility of the entire front panel by combining polygonal electrodes and circular electrodes and arranging them on the entire surface and connecting them with fine metal mesh wires.

FIGS. 8A to 8D show other arrangement examples of the front transparent conductive film and the fine metal wires used in the present invention. Each of the small area electrodes 25 in FIGS. 8A to 8D is a triangular small area electrode. The metal thin wires 23 are arranged in a triangular shape in FIG. 8A, in a quadrangular shape in FIG. 8B, and in a triangular honeycomb shape in FIGS. 8C and 8D.
Because the triangle is also the basic structure of the figure, even with rigid electrode materials, the flexible flat surface has high deformation follow-up, which is advantageous in terms of durability when the panel is repeatedly pushed in. Problems are less likely to occur).

  When erasing the contents written and displayed on the writing device in the middle of writing, the voltage applied to the counter electrode is switched so that the potential difference is reversed to reverse the direction of the electric field, and the writer 20 is placed at the portion to be erased. It can be done by pressing. When new information is written on the information display sheet on which the writing information is displayed, the information display sheet is attached to the writing device, and then the entire surface is erased by applying a voltage that applies an electric field equal to or higher than the drive threshold to the writing device. Subsequently, new handwritten writing is performed after the applied voltage is set to a state in which a voltage that gives an electric field smaller than the threshold is applied.

  FIGS. 9A and 9B each show a configuration example in which the entire information display sheet is displayed. In FIG. 9A, a white display medium 3Wa and a black display medium 3Ba are used to perform full screen display of black display with a white background or white display with a black background. In FIG. 9B, the yellow display medium 3Ya and the black display medium 3Ba are used to perform full-screen display of black display with a yellow background or yellow display with a black background. The information display sheet encloses the display medium in a cell (formed by the partition walls 4) between the front side substrate 14 and the back side substrate 15. The two color display media enclosed in the information display sheet have different charging characteristics, and the two colors combined as the display medium are preferably a combination of light and dark colors. Depending on the purpose of display, a combination of similar colors may be used, but a combination of black and white, yellow black, red white, blue white, or the like is preferably used.

  FIGS. 10A and 10B show configuration examples in which the information display sheet is displayed in area color. In FIG. 10A, a white display medium 3W made of display white particles 3Wa and a black display medium 3B made of display black particles 3Ba are sealed in the left half cell (formed by the partition 4), and the right half cell is filled. By enclosing the white display medium 3W composed of display white particles 3Wa and the red display medium 3R composed of display red particles 3Ra, an area color display of a white / black display area and a white / red display area is performed. . In FIG. 10B, a black display medium 3B composed of display black particles 3Ba and a yellow display medium 3Y composed of display yellow particles 3Ya are sealed in the left half cell, and display white particles 3Wa are enclosed in the right half cell. The white color display medium 3W and the red color display medium 3R consisting of the display red particles 3Ra are encapsulated to perform area color display of a black / yellow display area and a white / red display area.

FIGS. 11 (a) and 11 (b) show how information is written on the information display sheet using the writing device of the present invention. 11A and 11B, the left side of the arrow shows a state where the information display sheet 21 is inserted into the writing device 22 and the writing device 20 such as a pen is pressed against the front panel of the writing device. The right side of the arrow shows a state where the information display sheet that has been written is taken out. In FIG. 11A, a black display is performed on the entire surface with a white background. In FIG. 11 (b), area color display is performed in which one side is left and right, the left side is black with a white background, and the right side is red with a white background.
The size of the point for writing display (in the case of continuous writing, the thickness of the line) is determined by the size of the pen tip of the writing device 20. At the time of writing, the pen tip is pressed against the transparent front panel of the writing device. Therefore, the pen tip is preferably rounded so that damage to the panel can be reduced.

  Hereinafter, each member which comprises the writing apparatus of this invention and each member which comprises the information display sheet used as the object made writing display by this invention are demonstrated.

  First, a writing device front transparent panel (hereinafter referred to as front panel) of the writing device of the present invention, a panel substrate constituting a writing device rear panel (hereinafter referred to as rear panel), a conductive film, and an electrode protective layer optionally formed Will be explained.

The electrodes on the front panel need to be transparent, but the electrodes on the back panel need not be transparent. In consideration of frictional damage at the time of attaching / detaching the information display sheet, it is preferable that the electrode of the back panel is made of metal. The electrode thickness is preferably as thin as possible in the range of 3 to 400 nm on the front side, but it is not necessary to make it particularly thin on the back side, and a certain amount of thickness is required in consideration of frictional damage when the information display sheet is attached or detached. Since it is better to have it, the range is 3 to 3000 nm.
In addition to indium tin oxide (ITO), zinc-doped indium oxide (IZO), zinc oxide, indium oxide, antimony tin oxide (ATO), and conductive materials are used for the small area electrode (solid electrode) formed on the front panel. Examples include conductive metal oxides such as tin oxide and conductive zinc oxide, and conductive polymers such as polyaniline, polypyrrole, and polythiophene, and a transparent one is appropriately selected and used. In addition to indium tin oxide (ITO), conductive film materials to be formed on the back panel include zinc-doped indium oxide (IZO), zinc oxide, indium oxide, antimony tin oxide (ATO), conductive tin oxide, and conductive oxide. In addition to conductive metal oxides such as zinc, conductive polymers such as polyaniline, polypyrrole, and polythiophene, conductive general metal materials such as copper, aluminum, gold, and silver can be used.
As a method for forming an electrode, a method of forming the above-described materials into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or mixing a conductive agent with a solvent or a synthetic resin binder. The method of apply | coating is used. In any case, the above-mentioned material that can be patterned and is electrically conductive can be suitably used. In this case, the external voltage input may be superimposed with direct current or alternating current.
The electrode is configured by a so-called solid electrode whose entire surface is a conductive film, or a structure in which small-area electrode groups are connected by a thin metal wire.

As the front side transparent substrate 11 constituting the front panel, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic A transparent and flexible material is used.
As the substrate 18 constituting the back panel, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic, etc. A glass sheet, a metal sheet, or a quartz sheet can be used.

  A protective layer for the conductive film is provided on the front transparent panel and the back panel as required. When it is provided on the front panel, it is made of transparent material, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), polyethersulfone (PES), acrylic An acrylic transparent resin such as a resin is suitable. When the conductive film of the back panel is made of metal, a protective layer may not be provided on the back panel, but when it is provided, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate ( Acrylic resins such as PC), polyimide (PI), polyethersulfone (PES), and acrylic resin are preferable.

  Next, the board | substrate and partition provided in an information display sheet are demonstrated.

  The front substrate 14 of the information display sheet may be transparent so that the display medium can be seen, and a material having high visible light transmittance and good heat resistance is suitable. Substrate materials include non-flexible materials such as glass sheets and quartz sheets, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene (PE), polycarbonate (PC), polyimide (PI), and polyether. Transparent and flexible materials such as sulfone (PES) and acrylic can be used. Since the back side substrate 15 of the information display sheet does not need to be transparent, a resin sheet or a metal sheet containing a reinforcing material can be used in addition to those described above for the front side substrate 14. The thickness of the substrate is preferably 2 to 2000 μm, more preferably 5 to 1000 μm. If it is too thin, it will be difficult to maintain the strength and the uniform spacing between the substrates, and if it is thicker than 2000 μm, the distance between the electrodes of the writing device to be inserted Is too large, and there is a disadvantage that writing display cannot be performed by the writing device.

The height and width of the partition walls provided on the substrate of the information display sheet are appropriately set appropriately depending on the type of the display medium related to the display as required, and are not generally limited, but the width of the partition walls is 2 to 100 μm, preferably 3 to 50 μm. Further, the height of the partition wall is adjusted to 10 to 500 μm, preferably 10 to 200 μm. As shown in FIG. 10, the cells in the information display sheet obtained by superimposing the display side substrate and the back side substrate are illustrated in a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the substrate plane direction. Examples thereof include a lattice shape, a honeycomb shape, and a mesh shape. Other transparent microcapsules can also be used. Various shapes are used depending on the shape of the partition wall. 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 suitably used for the information display sheet of the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.
The total thickness of the information display sheet used in the writing device of the present invention is preferably 40 to 1000 μm.

  Next, a powder fluid used as a display medium, for example, in an information display sheet that performs writing display with the writing device of the present invention will be described. As for the name of the powder fluid used in the information display sheet used in the present invention, the present applicant has obtained the right of “Electronic Powder Fluid (registered trademark): Registration No. 4636931”.

  The “powder fluid” in the present invention is a substance in an intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. For example, liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of liquid and anisotropy (optical properties) that is a characteristic of solid (Heibonsha: Encyclopedia) . On the other hand, the definition of particle is an object with a finite mass even if it is negligible, and is said to be affected by gravity (Maruzen: Physics Encyclopedia). Here, even in the case of particles, there are special states of gas-solid fluidized bed and liquid-solid fluids. When gas is flowed from the bottom plate to the particles, upward force is applied to the particles according to the velocity of the gas. Is a gas-solid fluidized bed that is in a state where it can easily flow when it balances with gravity, and it is also called a liquid-solid fluidized state that is fluidized by a fluid (ordinary) Company: Encyclopedia). As described above, the gas-solid fluidized bed body and the liquid-solid fluid are in a state of using a gas or liquid flow. In the present invention, it has been found that a substance in a state of fluidity can be produced specifically without borrowing the force of such gas and liquid, and this is defined as powder fluid.

  That is, the pulverulent fluid in the present invention is in an intermediate state having both the characteristics of particles and liquid, as in the definition of liquid crystal (liquid and solid intermediate phase), and is the characteristic of the above-mentioned particles. It is a substance that is extremely unaffected and exhibits a unique state with high fluidity. Such a substance can be obtained in an aerosol state, that is, a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is used as a dispersoid in the information display sheet used in the present invention. To do.

The information display sheet that performs writing display with the writing device of the present invention is a powder that exhibits high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, in a gas between opposing substrates, at least one of which is transparent. This type of pulverulent fluid is so fluid that it does not form an angle of repose, which is an index indicating the fluidity of the powder, and is formed by applying a low voltage, etc. The electric field can be easily and stably moved by the Coulomb force or the like.
As described above, for example, the powder fluid used as the display medium in the present invention is a substance in the intermediate state between the fluid and particles that exhibits fluidity by itself without borrowing the force of gas or liquid. It is. This powder fluid can be in an aerosol state in particular, and the information display sheet used in the present invention is used as a display medium that can easily create a state in which a solid substance is suspended in a gas as a dispersoid relatively stably. .

Next, display particles (hereinafter also referred to as particles) constituting the display medium in the information display sheet that performs writing display with the writing device of the present invention will be described. The display particles may be composed of the display particles as they are to form a display medium, or may be combined with other particles to form a display medium, or may be adjusted and configured to become a powder fluid to form a display medium. Used.
The particles can contain a charge control agent, a colorant, an inorganic additive, and the like, if necessary, in the resin as the main component, as in the conventional case. Examples of resins, charge control agents, colorants, and other additives will be given below.

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

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

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

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

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 display agent of a desired color can be produced by blending the colorant.

  The display particles used in the display medium 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 display particles used in the display medium, the particle size distribution Span represented by 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, regarding the correlation between the display particles, the ratio of d (0.5) of the particles having the minimum diameter to d (0.5) of the particles having the maximum diameter among the used particles is 50 or less, preferably 10 or less. It is important. Even if the particle size distribution Span is reduced, particles with different charging characteristics move in opposite directions, so that the particle size is close to each other and each particle can be easily moved in the opposite direction by the equivalent amount. This is within this range.

The particle size distribution and particle size of the display 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 the particle size distribution are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, particles are introduced into a nitrogen stream and the attached analysis software (software based on volume-based distribution using Mie theory) The diameter and particle size distribution can be measured.

  The charge amount of the display particles naturally depends on the measurement conditions, but the charge amount of the display particles in the information display sheet is almost due to the initial charge amount, the contact with the partition walls, 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 display particles is a dominant factor.

  As a result of intensive studies, the present inventors have found that by using the same carrier particles in the blow-off method and measuring the charge amount of the display particles, it is possible to evaluate the range of the appropriate charging characteristic value of the display particles. .

Furthermore, when the information display sheet is a dry type information display sheet that drives the 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.
In FIG. 1A, FIG. 1B, and FIG. 1C, the void portion refers to the portion occupied by the display medium 3 (particle group or powder fluid) from the portion sandwiched between the opposing substrate 1 and substrate 2, and the partition 4 Occupying portion (when a partition wall is provided) and a gas portion in contact with a so-called display medium excluding a seal portion of the information display sheet.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in the information display sheet so that the humidity is maintained. For example, filling of the display medium, assembly of the information display sheet, etc. are performed in a predetermined humidity environment. It is important to apply a sealing material and a sealing method that prevent moisture from entering.

The distance between the substrate and the substrate in the information display sheet for performing writing display by the writing device of the present invention is only required to be able to move the display medium and maintain the contrast, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm. .
In the case of a dry information display sheet, the volume occupancy of the display medium in the space between the opposing substrates 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.

According to the writing device of the present invention, handwritten writing can be repeatedly performed on the information display sheet, so that the information display sheet can be used as recycled memo paper, recycled notebook, recycled advertising card, and the like.
The writing device of the present invention can display information such as images by handwriting on a charged particle driving type information display sheet having display memory properties. Design together. When the information display sheet is a small one having an A4 size or smaller, the writing device of the present invention can be a small one having an A4 size or smaller, so that the writing device having excellent portability can be obtained. By using a small battery or a thin battery as a display medium driving power source for applying a voltage to the front panel electrode and the rear panel electrode, a writing device can be used wherever writing is performed. The writing device of the present invention can also be used as a handwritten writing display device for information with one information display sheet still inserted.

(A), (b) is a figure which shows an example of the information display sheet which this invention uses, respectively. (A)-(c) is a figure for demonstrating the writing apparatus of the information display sheet of this invention, respectively. (A)-(d) is a figure for further demonstrating the writing apparatus of the information display sheet of this invention, respectively. (A)-(f) is an example of preparation of the front side transparent conductive film used for this invention, respectively. (A)-(f) is each the other example of preparation of the front side transparent conductive film used for this invention. (A), (b) is an example of arrangement | positioning of the front side transparent conductive film used for this invention, respectively. (A)-(f) is each the other example of arrangement | positioning of the front side transparent conductive film used for this invention. (A)-(d) is another example of arrangement | positioning of the front side transparent conductive film used for this invention, respectively. (A), (b) shows the example of a structure which respectively displays an information display sheet on the whole surface. (A), (b) each shows the structural example which displays an information display sheet in area color. (A), (b) shows a mode that writing is performed on an information display sheet by the writing device of the present invention. It is a figure which shows an example of the shape of the partition in the information display sheet which performs a writing display with the writing device of this invention.

Explanation of symbols

1, 2 Substrate 3 Display medium 3W White display medium 3Wa Display white particle 3B Black display medium 3Ba Display black particle 3Y Yellow display medium 3Ya Display yellow particle 3R Red display medium 3Ra Display red particle 4 Partition 11 Front side of writing device Flexible transparent substrate 12 Writing device front side transparent conductive film 13 Writing device front side protective layer 14 Front side substrate of information display sheet 15 Back side substrate of information display sheet 16 Writing device back side protective layer 17 Writing device back side conductive film 18 Writing device back side substrate 20 Writing device 21 Information display sheet 22 Writing device

Claims (9)

At least one display medium having at least one kind of particles and having optical reflectivity and chargeability is disposed between two opposing substrates, at least one of which is transparent, and an electric field is applied to the display medium. In the writing device that includes an information display sheet that displays information such as an image by moving the display medium, and performs writing display,
The information display sheet is detachable from the writing device,
Provide a writing device front transparent panel on the viewing side of the writing device,
A front side transparent conductive film is disposed on the writing device front transparent panel,
The front-side transparent conductive film is composed of a solid electrode and a mesh-like metal fine wire that is in contact with the upper and lower surfaces of the solid electrode or is embedded and in contact with the solid electrode,
A writing device rear panel is provided on the opposite side of the writing device from the viewing side,
A back side conductive film is disposed on the writing device back panel,
Inserting the information display sheet into the space between the writing device front transparent panel and the writing device back panel;
A space is provided between the writing device front transparent panel and the inserted information display sheet,
A voltage is applied between the front transparent conductive film and the rear conductive film to form an electric field that is smaller than a drive threshold of an electric field driven by the display medium,
Press the writing device against the front transparent panel of the writing device and deflect it.
By reducing the distance between the front-side transparent conductive film and the back-side conductive film, the electric field formed between the two conductive films becomes equal to or greater than the driving threshold.
A writing apparatus for an information display sheet, wherein the display medium is moved to perform writing display. At least one display medium having at least one kind of particles and having optical reflectivity and chargeability is disposed between two opposing substrates, at least one of which is transparent, and an electric field is applied to the display medium. In the writing device that includes an information display sheet that displays information such as an image by moving the display medium, and performs writing display,
The information display sheet is detachable from the writing device,
Provide a writing device front transparent panel on the viewing side of the writing device,
A front side transparent conductive film is disposed on the writing device front transparent panel,
The front-side transparent conductive film is composed of a small area electrode group and a mesh-like metal fine wire in contact with all of the small area electrode group,
A writing device rear panel is provided on the opposite side of the writing device from the viewing side,
A back side conductive film is disposed on the writing device back panel,
Inserting the information display sheet into the space between the writing device front transparent panel and the writing device back panel;
A space is provided between the writing device front transparent panel and the inserted information display sheet,
A voltage is applied between the front transparent conductive film and the rear conductive film to form an electric field that is smaller than a drive threshold of an electric field driven by the display medium,
Press the writing device against the front transparent panel of the writing device and deflect it.
By reducing the distance between the front-side transparent conductive film and the back-side conductive film, the electric field formed between the two conductive films becomes equal to or greater than the driving threshold.
A writing apparatus for an information display sheet, wherein the display medium is moved to perform writing display.   3. The information display sheet writing apparatus according to claim 1, wherein the solid electrode or the small-area electrode group is formed so as to cover the fine mesh metal wire. 4.   3. The information display sheet writing apparatus according to claim 2, wherein the small area electrode group is arranged so as to be connected by the fine mesh metal wire.   3. The information display sheet writing apparatus according to claim 2, wherein the small area electrode group has any one of a triangular shape, a rectangular shape, a circular shape, a hexagonal shape, and a line shape.   3. The information display sheet writing apparatus according to claim 1, wherein the mesh shape of the mesh-like metal thin wire is a quadrangle or a triangle.   When erasing the displayed contents during writing, switch the voltage applied between the two conductive films so that the potential difference is reversed, reverse the electric field direction, and press the writer on the part you want to erase. The information display sheet writing apparatus according to claim 1, wherein the information display sheet writing apparatus is a writing apparatus.   When new information is written after erasing the displayed information, the entire surface is erased by applying a voltage that forms an electric field equal to or higher than the driving threshold of the electric field between the conductive films. 3. The information display sheet writing apparatus according to claim 1, wherein the new handwritten writing is performed after an applied voltage that forms a small electric field.   The gap thickness between the lower surface of the writing device front transparent panel and the upper surface of the writing device rear panel has an interval of 1.2 to 2 times the thickness of the information display sheet. 3. The information display sheet writing device according to any one of 1 and 2.

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