JP2004287011A - Image display medium, its manufacturing method, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium having an inexpensive and high quality non-display substrate with an electrode, and to provide its manufacturing method and an image forming device. <P>SOLUTION: An image display medium 10 has a transparent display substrate 14 on which a transparent electrode 16 is provided and a non-display substrate 20 on which an electrode 22 is provided as a pair of the substrates, spacers 26 are held between the display substrate 14 and the non-display substrate 20 while the electrode sides of them are opposed to each other and white particles 30 which can be positively or negatively charged and black particles 28 which can be charged in a potential reverse to the potential of the white particles 30 are enclosed in a space formed by the spacers 26 between the substrates. The transparent electrode 16 of the display substrate 14 and an electric field generating means 12 are connected to each other and the electrode 22 of the non-display substrate 20 is grounded. In this constitution, the electrode 22 to be provided on the non-display substrate 20 is formed by using a screen printing method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６３】
表１の結果から、非表示基板上に、スクリーン印刷により印刷された電極（非表示側電極）は、リーク率が少なくなっており、低コストで高精細な電極パターンとなっていることがわかる。また、スクリーン印刷により高精細な電極パターンを形成するには、非表示基板の表面粗さを適度な範囲としたり、下地層を形成することがよいことがわかる。さらに、電極付き非表示基板の表面粗さを、適度な範囲とすることで、駆動電力が低下くても良好に駆動させることが可能であることがわかる。なお、電極付き非表示基板の表面粗さが適度な範囲外であっても、実用上問題ないレベルでリーク率が抑制され、また、若干の不良が生じたが実用に耐え得る駆動表示が行なえた。
【００６４】
【発明の効果】
以上、本発明によれば、低コストで高品質な電極付き非表示基板を有する画像表示媒体及びその製造方法、並びに、画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る画像形成装置を示す概略構成図である。
【図２】本発明の実施の形態に係る画像形成装置に適用される電極付き非表示基板の一例を示す概略平面図である。
【図３】本発明の実施の形態に係る画像形成装置に適用される電極付き非表示基板の他の一例を示す概略平面図である。
【符号の説明】
１０ 画像表示媒体
１２ 電界発生手段
１４ 透明表示基板
１６ 透明電極
１８ 表面層
２０ 非表示基板
２２ 電極
２４ 表面層
２６ スペーサー
２８ 黒色粒子
３０ 白色粒子
３２ 下地層
３４ 孔[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image display medium capable of repeatedly rewriting an image by driving a group of charged particles by an electric field, a method of manufacturing the same, and an image forming apparatus.
[0002]
[Prior art]
As one of the techniques for displaying a desired image on a display element by electricity, an electronic paper technique is known. Electronic paper having a configuration in which a liquid display element or a display liquid in which the display element is dispersed in a liquid is sealed between opposing substrates, using, for example, electrophoresis, thermal rewritable, liquid crystal display, and electrochromy techniques Things. In addition, a display element of two different colors (for example, black particles and white particles) is sealed between two opposing display substrates each formed by laminating an electrode and a dielectric layer. The electronic paper uses, for example, the technology of a particle display element.
[0003]
In the particle display element, when an electric field is applied between two pairs of substrates, particles of two colors having different polarities due to triboelectricity move and adhere to one of the display substrate and the display substrate according to the polarity of the particles. . When the polarity of the electric field between the display substrates is switched, the particles of the two colors move and adhere to the other display substrate facing the currently attached display substrate. At this time, since the non-electrostatic adhesion (Van der Waals force) and the electrostatic adhesion (Coulomb force) maintain the adhesion on the substrate wall, even if the electric field applied between the display substrates is cut off. The particles do not release from the display substrate.
[0004]
In addition, in order to move the particles by overcoming this adhesive force, it is necessary to apply an electric field of a certain value or more, and there is a so-called “threshold” electric field where the particles do not move below the electric field. , Simple matrix driving (passive matrix driving) can be performed. That is, the electric field is maintained under the condition that the particle moves below the “threshold” between the adjacent electrodes, and a predetermined voltage is sequentially applied to the opposing electrode to apply the electric field equal to or more than the “threshold”. The particles can be moved by selectively creating portions. Compared to dot matrix driving, this passive matrix driving eliminates the need to form a control element for each pixel, which simplifies the device, increases the yield, lowers costs, and makes it relatively easy to increase the screen size. It has advantages such as becoming.
[0005]
The particle display element can display both characters and graphics by a passive matrix method. It describes that two substrates on which stripe electrodes are formed are opposed to each other so that the electrodes intersect in a grid pattern. When an electrical signal is sent with the timing of the vertical and horizontal electrodes synchronized, the pixels where the vertical and horizontal electrodes to which the signal is sent intersect are displayed, so the combination of vertical and horizontal electrodes is selected. Can be displayed simultaneously. By using an electrode on which an arbitrary pattern is formed, an arbitrary pattern can be displayed.
[0006]
By the way, as a method of forming a stripe electrode, a method of patterning a sputtering thin film of ITO by chemical etching, a method of patterning by laser ablation, a method of patterning a copper electrode substrate by chemical etching, and the like have been known (for example, And JP-A-9-127530 and JP-A-2001-92388.
[0007]
[Patent Document 1]
JP-A-9-127530 [Patent Document 2]
JP-A-2001-92388
[Problems to be solved by the invention]
However, none of these methods was excellent in cost, environment, and productivity.
[0009]
The method of forming electrodes by pattern printing is advantageous in terms of production cost due to its high material efficiency, but it is difficult to respond to high definition. In particular, when a glass substrate is used to ensure long-term dimensional stability, or when a resin film is used to support flexibility and lightness, a high-definition pattern can be generated due to its surface properties. was difficult.
[0010]
Accordingly, an object of the present invention is to solve the above-described conventional problems and achieve the following objects. That is, an object of the present invention is to provide a low-cost, high-quality image display medium having a non-display substrate with electrodes, a method of manufacturing the same, and an image forming apparatus.
[0011]
[Means for Solving the Problems]
The above problem is solved by the following means. That is, the present invention
(1) A transparent display substrate, a non-display substrate disposed opposite to the transparent display substrate, and a positive or negative encapsulated in a space provided between the transparent display substrate and the non-display substrate. An image display medium having one or more charged particles that can be charged,
An image display medium, wherein the non-display substrate is provided with an electrode printed by screen printing.
[0012]
(2) The image display medium according to (1), wherein at least one of the charged particle groups has the same color as the color of the electrode printed by the screen printing.
[0013]
(3) The image display medium according to (1) or (2), wherein the surface roughness of the non-display substrate on which the electrodes are printed is Ra 0.1 μm or more and 5 μm or less.
[0014]
(4) The image display medium according to any one of (1) to (3), wherein the non-display substrate is a glass substrate.
[0015]
(5) The image display medium according to any one of (1) to (3), wherein the non-display substrate is a resin substrate.
[0016]
(6) The image display medium according to any one of (1) to (3), wherein the non-display substrate is a resin film substrate.
[0017]
(7) The image display medium according to any one of (1) to (6), wherein the electrodes are printed on the non-display substrate via a base layer.
[0018]
(8) The image display medium according to any one of (1) to (7), wherein the printing material of the electrode is a paste material selected from silver, copper, aluminum, and carbon.
[0019]
(9) An image forming apparatus including: an image display medium for displaying an image; and an electric field generating unit that generates an electric field corresponding to the image in order to display the image on the image display medium,
An image forming apparatus, wherein the image display medium is the image display medium according to any one of (1) to (8).
[0020]
(10) A transparent display substrate, a non-display substrate disposed opposite to the transparent display substrate, and a positive or negative encapsulated in a space provided between the transparent display substrate and the non-display substrate. A method for producing an image display medium comprising: one or more charged particles capable of being charged;
A method of manufacturing an image display medium, comprising printing electrodes on the non-display substrate by screen printing.
[0021]
(11) The method for producing an image display medium according to (10), wherein the electrodes are printed so that the surface roughness of the non-display substrate is Ra 0.1 μm or more and 5 μm or less.
[0022]
(12) The method for producing an image display medium according to (10) or (11), wherein the electrode is printed on the non-display substrate via a base layer.
[0023]
(13) The image display medium according to any one of (10) to (12), wherein the printing material of the electrode is a paste material selected from silver, copper, aluminum, and carbon. Manufacturing method.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings. Note that members having substantially the same function are denoted by the same reference numerals throughout the drawings and described.
[0025]
FIG. 1 shows an image forming apparatus according to an embodiment of the present invention. The image forming apparatus illustrated in FIG. 1 includes an image display medium 10 for displaying an image, and an electric field generating unit 12 that generates an electric field corresponding to the image between a pair of substrates of the image display medium 10. .
[0026]
The image display medium 10 includes, as a pair of substrates, a transparent display substrate 14 on which a transparent electrode 16 is provided and a non-display substrate 20 on which an electrode 22 is provided. The spacers 26 are sandwiched with the sides facing each other, and the white particles 30 that can be positively or negatively charged and the white particles 30 can be charged to the opposite charge to the space between the substrates provided by the spacers 26. Black particles 28 are enclosed. Then, the transparent electrode 16 of the display substrate 14 and the electric field generating means 12 are connected, and the electrode 22 of the non-display substrate 20 is grounded.
[0027]
In the image display medium 10, the black particles 28 and the white particles 30 are mixed at a weight ratio of, for example, 1: 2 to 1: 1. A desired amount is filled by means such as shaking off the space delimited by a screen, and thereafter, the display substrate 14 is brought into close contact, the pressure between the two substrates is maintained, and the spacer 26 is brought into close contact with both substrates. Can be made. The image display medium 10 may be appropriately provided with a functional film such as an ultraviolet cut filter and an anti-reflection film depending on the purpose of use.
[0028]
An electrode 22 and a surface layer 24 are sequentially provided on the surface of the non-display substrate 20. In the present embodiment, the electrodes 22 are printed by screen printing and provided in stripes. In screen printing, a screen on which an opening pattern is formed is placed on a substrate to be printed, and printing is performed by using the opening pattern to attach a paste material (electrode material) only to the opening pattern portion. It is possible to form a high-definition pattern at low cost and to obtain a low-cost and high-quality electrode.
[0029]
The surface of the non-display substrate 20 has a surface roughness Ra of 0.1 μm or more and 10 μm or less (preferably 0.25 μm or more and 5 μm or less, more preferably 0.1 μm or less, in order to print a fine electrode pattern by screen printing. 25 μm or more and 3 μm or less). When the surface roughness Ra is 0.1 μm or less, the surface is smooth, and the flowable paste material easily flows on the substrate at the time of discharge from the screen, causing a desired pattern to be non-uniform and deteriorating display quality. May be invited. Further, when the surface roughness Ra is 10 μm or more, an electrode pattern is formed along the substrate roughness, so that the straightness of the pattern interface is impaired, and the display quality is deteriorated. May cause a leak.
[0030]
The paste material for forming the electrodes 22 for performing the screen printing can be appropriately selected and used from metal, carbon, or the like depending on surface resistivity, film thickness, strength, cost, and the like. In particular, the paste material is preferably selected from silver, copper, aluminum, and carbon. The metal paste material can reduce the voltage drop and improve the display quality because the resistivity can be lowered, and the carbon paste material is very effective in terms of cost. , The display quality can be improved.
[0031]
As shown in FIGS. 2 and 3, even if the surface of the non-display substrate 20 is not roughened as described above, an underlayer 32 is provided on the non-display substrate 20, and an electrode is provided through the underlayer. By printing 22 by screen printing, wettability with the electrode material is improved, so that a high-definition striped electrode can be formed.
[0032]
As shown in FIG. 2, the underlayer 32 has the same width as the pattern of the stripe-shaped electrode 22 (or the width of the space on the electrode formation if the width is larger than the width of the electrode 22) within a range that does not affect the formation of the electrode 22 pattern. 3), or as shown in FIG. 3, on the entire surface of the substrate. When the underlayer 32 is provided on the entire surface of the substrate, it is effective to provide holes 34 for light transmission in the underlayer 32 as shown in FIG. For example, the hole 34 can function as a transmission hole when a photo-curing adhesive is used at the time of rib joining, or can be provided on the rear surface side of the display substrate, so that the influence of the protrusion of the adhesive on the display is eliminated. It is effective because it can.
[0033]
To form the underlayer 32, a method such as screen printing, dipping, or spray coating can be applied. Among them, screen printing is optimal because it can be formed into any shape with high precision.
[0034]
As described above, since the electrodes 22 are printed by screen printing using the paste material, the non-display substrate 20 can be appropriately roughened. The surface of the non-display substrate with electrodes 20 thus roughened has an effect that the driving voltage can be reduced because the contact area with the particles is reduced. In this case, the surface roughness Ra of the surface of the non-display substrate with electrodes 20 is preferably 0.1 μm or more and 5 μm or less (more preferably 0.3 μm or more and 3 μm or less, and still more preferably 0.3 μm or more and 1.5 μm or less). It is. If the surface roughness Ra is 0.1 μm or less, no particular effect is obtained on the drive voltage. If the surface roughness Ra is 5 μm or more, the straightness of the electrode edge is impaired, and it may be difficult to achieve high definition. In the present embodiment, the surface layer 24 is provided, but the surface layer 24 is formed roughly following the surface of the electrode 22, so that the above-described effect can be obtained.
[0035]
The non-display substrate 20 is not particularly limited, but when a high-quality substrate is manufactured, it is effective to use glass having high planarity and high dimensional stability. By using a glass substrate, the gap between the substrates can be kept uniform, and stable long-term repetitive display can be performed regardless of the use environment. Further, in the case of mounting and displaying on a curved surface as an application, it is effective to use a flexible resin substrate or resin film as the non-display substrate 20. In this case, it is also beneficial that it is lightweight and effective in handling, and that the risk of breakage and the like is small. In this embodiment, it is also possible to print a high-definition pattern electrode on these substrates by screen printing.
[0036]
After the electrodes 22 are printed, the non-display substrate 20 can be subjected to various processes on the surface thereof as needed, as long as the display image quality is not affected. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed.
[0037]
On the other hand, a transparent electrode 16 and a surface layer 18 are sequentially provided on the surface of the transparent display substrate 14. The transparent electrode 16 includes a thin film of a metal oxide such as tin oxide, indium oxide, and indium tin oxide (ITO).
[0038]
The surface layers 18 and 24 of the display substrate 14 and the non-display substrate 20 may be formed directly on the electrodes 16 and 22, respectively. However, depending on the volume resistivity, a thin film may be used to prevent charge injection from the electrodes 16 and 22. May be provided.
[0039]
The spacer 26 is made of, for example, ethylene propylene diene rubber (EPDM), polybutadiene, natural rubber, polyisobutylene, styrene butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), silicon rubber, urethane rubber, epichlorohydrin A sheet of rubber, styrene-butadiene-styrene rubber (SBS), thermoplastic elastomer, norbornene rubber, fluorosilicone rubber, ethylene oxide rubber, or the like can be cut out to a desired size and formed. Alternatively, a spacer 26 having a desired shape can be formed by applying an ultraviolet curable resin or the like on the electrode in advance, exposing the film using a photomask, and developing unnecessary portions. Alternatively, the spacer 26 having a desired shape can be formed by screen printing using a thermosetting ink. The thickness of these spacers 26 is 50 μm to 1000 μm, preferably 100 μm to 500 μm.
[0040]
As the black particles 28 as the charged particles, for example, spherical resin particles containing carbon black, titanium black, magnetic powder, oil black, organic and inorganic dye / pigment black materials are used. On the other hand, as the white particles 30, for example, spherical resin particles containing a white pigment such as rutile-type titanium oxide, anatase-type titanium oxide, zinc white, lead white, zinc sulfide, aluminum oxide, silicon oxide, and zirconium oxide are used. As the white pigment, particularly, rutile-type titanium oxide is preferably used. Further, other chromatic particles may be used as the charged particle group. The chromatic particles include phthalocyanine-based, quinacridone-based, azo-based, condensation-based, insoluble lake pigment, inorganic oxide-based dyes and pigments (for example, Specifically, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, CI pigment red 48 1, CI Pigment Red 122, CI Pigment Red 57: 1, CI Pigment Yellow 97, CI Pigment Yellow 180, CI Pigment Yellow 185, CI Pigment Blue 15: 1, CI Pigment DOO Blue 15: 3, etc.) can be used spherical resin particles containing.
[0041]
At least one of the charged particle groups is preferably the same color as the color of the electrode 22 provided on the non-display substrate 20, and all of the charged particle groups are the same as the electrode 22 provided on the non-display substrate 20. (Or the color of the electrode 22 is selected in this way). By making the color of at least one charged particle group and the color of the electrode 22 the same color, the density of the same color can be increased and the contrast is improved.
[0042]
In the image forming apparatus of the present embodiment, for example, when a DC voltage of 200 V is applied to the transparent electrode 3 of the display substrate 14, a part of the negatively charged white particles 30 on the non-display substrate 20 side acts as an electric field. When the DC voltage of 500 V is applied, many white particles move to the display side, and the display density is almost saturated. At this time, the black particles 28 charged to the positive polarity move to the non-display substrate 20 side. Here, even if the voltage is set to 0 V, the particles on the display substrate 14 do not move, and the display density does not change.
[0043]
Further, when a DC voltage of -200 V is applied to the transparent electrode 3, some of the black particles 28 move to the display substrate 14 side to display black. Here, even when the voltage was set to 0 V, the particles on the display substrate 14 did not move, and the display density did not change. By repeating the above steps, it is possible to reversibly invert white / black.
[0044]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.
[0045]
<Example 1>
-Fabrication of display substrate-
As a display substrate, a 7059 glass substrate with a transparent ITO having a length x width x thickness = 50 mm x 50 mm x 1.1 mm is prepared. On the surface of the display substrate, a display-side electrode (line / space = 980/20 μm) formed of ITO is formed. A voltage controller is connected to the display-side electrode. The spacer is obtained by laminating four 50 μm dry films on a display substrate as a spacer, and exposing and developing by photolithography. Height 200 μm, width 100 μm, (pitch is the same as electrode). On the surface of the display-side electrode, 10 parts by weight of a polycarbonate resin (Iupilon Z, manufactured by Mitsubishi Gas Chemical) was dissolved in 90 parts by weight of toluene, dip coated, dried at 120 ° C. for 30 minutes, and dried to a thickness of 1.0 μm. A surface layer is provided.
[0046]
-Fabrication of non-display substrate-
As a non-display substrate, a substrate was prepared by pressing a glass epoxy substrate with a surface roughness Ra of 0.25 by pressing, and lines / spaces = 900/100 μm were formed on this substrate by screen printing. As the conductive paste material used at this time, a carbon paste obtained by dispersing carbon in a thermosetting resin was used (manufactured by Asahi Chemical Laboratory: TU13SK). On the non-display-side electrode formed in black, a surface layer was formed in the same manner as the display-side electrode. Table 1 shows the surface roughness and printing result of the non-display substrate with electrodes at this time. The printing result was evaluated based on the space / line width and the leak rate when 200 V was applied between the adjacent areas.
[0047]
―Preparation of white particles―
-Cyclohexyl methacrylate: 53 parts by weight, titanium oxide: (Taipec CR63: manufactured by Ishihara Sangyo): 45 parts by weight, charge control agent: (COPY CHARGE PSY VP2038: manufactured by Clariant Japan): 2 parts by weight, and cyclohexane: 5 Using a zirconia ball having a weight part of 10 mmΦ, ball mill pulverization was performed for 20 hours. This dispersion was designated as A.
[0048]
Calcium carbonate: 40 parts by weight and water: 60 parts by weight were finely pulverized by a ball mill in the same manner as above to prepare a carbon cal dispersion liquid B.
[0049]
A 2% aqueous solution of cellogen: 4.3 g, 8.5 g of charcoal dispersion B, and 50 g of 20% saline solution were mixed, degassed by an ultrasonic machine for 10 minutes, and then stirred by an emulsifier (mixture C).
[0050]
35 g of the dispersion A, 1 g of divinylbenzene, and 0.35 g of a polymerization initiator AIBN were weighed, mixed well, and deaerated with an ultrasonic machine for 10 minutes. This was put in the mixture C and emulsified by an emulsifier. Next, this emulsified liquid was finely added, the silicone was slid, the air was sufficiently degassed under reduced pressure using an injection needle, and sealed with nitrogen gas. Next, particles were prepared by reacting at 60 ° C. for 10 hours. After cooling, the cyclohexane was removed from this dispersion by a freeze dryer at -35 ° C and 0.1 Pa for 2 days. The obtained fine particle powder was dispersed in ion-exchanged water, calcium carbonate was decomposed with aqueous hydrochloric acid, and filtration was performed. Thereafter, it was washed with sufficient distilled water and passed through a nylon sieve having openings of 20 μm and 25 μm to uniform the particle size. This was dried to obtain white particles having an average particle size of 23 μm.
[0051]
-Preparation of black particles-
A styrene monomer: 87 parts by weight, a black pigment: carbon black: (CF9: manufactured by Mitsubishi Chemical): 10 parts by weight, and cyclohexane: 5 parts by weight were subjected to ball mill pulverization for 20 hours using zirconia balls of 10 mmφ. Thereafter, black particles having an average particle diameter of 23.2 μm were obtained in the same manner as the white particles 1.
[0052]
-Preparation of image display medium-
Each of the particles was quantified by grinding with a slab having a prescribed shape, and after facing the display substrate on which ribs were formed as spacers, the particles were sieved by vibration and filled. Then, after removing excess particles adhering to the rib shape with a blade, a UV curable adhesive is applied only to the intersection at a diameter of 50 μm with a dispenser. The non-display substrate is superimposed and adhered so that the rib portion is located between the printed electrodes, and the above-mentioned white particles and black particles obtained by irradiating UV light from above and joining both substrates are in a weight ratio of 2: 1. 15 mg of the mixed particles mixed in the ratio described above were enclosed. The white particles were negatively charged and the black particles were positively charged.
[0053]
In the image display medium having such a configuration, when a positive DC voltage is applied to the display-side electrode of the image display unit, the negatively charged white particles existing on the non-display substrate side cause the electric field to act on the display substrate side. Move to At this time, the black particles charged to the positive polarity move to the non-display substrate side. Thereafter, even when the voltage was set to 0 V, the particles on the display substrate did not move, and no change was observed in the display density. Table 1 shows the driving display results at this time.
[0054]
<Example 2>
Before printing electrodes on a glass epoxy substrate as a non-display substrate, all images were formed in the same manner as in Example 1 except that screen printing was performed using Asahi Chemical Laboratory: CCR-232CFV to form a single underlayer. A display medium was prepared and evaluated.
[0055]
<Example 3>
An image display medium was prepared and evaluated in the same manner as in Example 2 except that the non-display substrate was a glass substrate (surface roughness Ra 0.03 μm).
[0056]
<Example 4>
An image display medium was prepared and evaluated in the same manner as in Example 2 except that the non-display substrate was a polycarbonate resin substrate (surface roughness Ra: 0.05 μm).
[0057]
<Example 5>
An image display medium was prepared and evaluated in the same manner as in Example 1 except that the non-display substrate was an etched glass substrate.
[0058]
<Example 6>
An image display medium was prepared and evaluated in the same manner as in Example 1 except that a glass epoxy substrate (surface roughness Ra 0.05 μm) whose surface was not roughened was used for the back substrate.
[0059]
<Example 7>
An image display medium was prepared and evaluated in the same manner as in Example 1 except that the back substrate was a glass substrate (surface roughness Ra: 0.03 μm).
[0060]
Example 8
An image display medium was prepared and evaluated in the same manner as in Example 1 except that the back substrate was an etched glass substrate (surface roughness Ra 10.5 μm).
[0061]
<Comparative Example 1>
An image display medium was prepared and evaluated in the same manner as in Example 1 except that a glass on which an ITO electrode was vapor-deposited and etched into an electrode pattern was used as a non-display substrate.
[0062]
[Table 1]

[0063]
From the results in Table 1, it can be seen that the electrode (non-display side electrode) printed on the non-display substrate by screen printing has a low leak rate, and has a low-cost and high-definition electrode pattern. . Further, it can be seen that in order to form a high-definition electrode pattern by screen printing, it is preferable to set the surface roughness of the non-display substrate to an appropriate range or to form an underlayer. Further, it can be seen that by setting the surface roughness of the non-display substrate with electrodes in an appropriate range, it is possible to drive well even if the driving power is reduced. In addition, even if the surface roughness of the non-display substrate with electrodes is out of an appropriate range, the leak rate can be suppressed to a level that does not cause a problem in practical use, and a drive display that can withstand practical use with some defects can be performed. Was.
[0064]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a low-cost, high-quality image display medium having a non-display substrate with electrodes, a method for manufacturing the same, and an image forming apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic plan view showing an example of a non-display substrate with electrodes applied to the image forming apparatus according to the embodiment of the present invention.
FIG. 3 is a schematic plan view showing another example of the non-display substrate with electrodes applied to the image forming apparatus according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Image display medium 12 Electric field generation means 14 Transparent display substrate 16 Transparent electrode 18 Surface layer 20 Non-display substrate 22 Electrode 24 Surface layer 26 Spacer 28 Black particle 30 White particle 32 Underlayer 34 Hole

Claims (13)

A transparent display substrate, a non-display substrate disposed opposite to the transparent display substrate, and sealed in a space provided between the transparent display substrate and the non-display substrate, which can be positively or negatively charged. An image display medium having one or more charged particle groups,
An image display medium, wherein the non-display substrate is provided with an electrode printed by screen printing. 2. The image display medium according to claim 1, wherein at least one of the charged particle groups has the same color as the color of the electrode printed by the screen printing. 3. The image display medium according to claim 1, wherein the surface roughness of the non-display substrate on which the electrode is printed is Ra not less than 0.1 μm and not more than 5 μm. The image display medium according to claim 1, wherein the non-display substrate is a glass substrate. The image display medium according to claim 1, wherein the non-display substrate is a resin substrate. The image display medium according to claim 1, wherein the non-display substrate is a resin film substrate. The image display medium according to claim 1, wherein the electrodes are printed on the non-display substrate via a base layer. The image display medium according to any one of claims 1 to 7, wherein a printing material of the electrode is a paste material selected from silver, copper, aluminum, and carbon. An image forming apparatus comprising: an image display medium for displaying an image; and an electric field generating unit configured to generate an electric field corresponding to the image in order to display the image on the image display medium.
An image forming apparatus, wherein the image display medium is the image display medium according to claim 1. A transparent display substrate, a non-display substrate disposed opposite to the transparent display substrate, and sealed in a space provided between the transparent display substrate and the non-display substrate, which can be positively or negatively charged. A method for producing an image display medium comprising: one or more charged particle groups;
A method of manufacturing an image display medium, comprising printing electrodes on the non-display substrate by screen printing. The method of manufacturing an image display medium according to claim 10, wherein the electrode is printed so that the surface roughness of the non-display substrate is Ra 0.1 μm or more and 5 μm or less. The method for manufacturing an image display medium according to claim 10, wherein the electrode is printed on the non-display substrate via a base layer. 13. The method according to claim 10, wherein a printing material of the electrode is a paste material selected from silver, copper, aluminum, and carbon.

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