JP2003015169A - Picture display medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable display characteristic over a long period by improving maintainability. SOLUTION: A voltage application means 20 applies a predetermined voltage across a 1st electrode arranged on a display substrate 12 and a 2nd electrode arranged on a non-display substrate. Sealing means 16, 22 are provided in the peripheral parts of the display substrate and the non-display substrate, and the display substrate and the non-display substrate are held to keep a predetermined distance in-between and a predetermined closed space 18 is formed between them. Particle groups 30, 32 are filled in the closed space, and are movable between the 1st electrode and the 2nd electrode by the electric field generated by the voltage applied by the voltage application means. A humidity detection means 24 detects humidity of the closed space, and a monitoring means 26 monitors the humidity of the closed space based on the detected humidity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display medium, and more particularly to an image display medium that can be repeatedly rewritten.

[0002]

2. Description of the Related Art Conventionally, as a type of image display means, a rewritable sheet-like image display medium,
Image display media such as electrophoresis, thermal rewritable media, liquid crystal having a memory property, and electrochromy have been proposed. Such an image display medium has a configuration in which a liquid display element (a liquid display element or a display element dispersed in a liquid) is enclosed between a display substrate and a non-display substrate facing the display substrate. .

Similarly, as a rewritable sheet-shaped image display medium, electrodes and dielectric layers are provided on a display substrate and a non-display substrate, and a particulate display element is provided between the display substrate and the non-display substrate. There is also a configuration in which (black particles and white particles) are enclosed.

Specifically, the conventional image display medium is composed of a plurality of display elements 80, and each display element 80 has a display substrate 82 (substrate 82a, electrodes 82b,
A dielectric layer 82c) and a non-display substrate 84 (a substrate 84a, an electrode 84b, a dielectric layer 84c) facing the display substrate 82 are provided. Further, a spacer 86 is provided between the display substrate 82 and the non-display substrate 84 of the display element 80, and a seal member 88 is provided on the outer peripheral portion of the spacer 16. The display substrate 84 and the display substrate 84 are arranged at a predetermined interval, and the display substrate 12, the non-display substrate 84, and the spacer 86 form a closed space 90. Then, a particle group consisting of white particles 92 and black particles 94 is enclosed in this space.

In the image display medium using the latter particles, the triboelectrically charged powders 92 and 94 of two different colors are formed on the display substrate 8.
2 and the electrodes 82b and 84b provided on the non-display substrate 84
It moves by the action of the electric field generated by the voltage applied between them. That is, from the voltage applying device 96 to the substrates 82, 8
When a voltage is applied between the electrodes 4, an electric field is generated between the substrates 82 and 84, and the particles charged by this electric field move to the display substrate 82 side or the non-display substrate 84 side depending on the polarity. When the voltage application between the substrates 82 and 84 is stopped, the particles 9
2, 94 are attached and held by the dielectric layers 82c, 84c provided on the display substrate 82 or the non-display substrate 84.
The image display medium using particles can be displayed in this manner.

[0006]

However, in the image display medium using the above-mentioned particles, the particles are moved by an electric field by utilizing triboelectric charging between particles (powder) of two different colors. , When the charged state of the particles changes due to the change of humidity, and the charged state changes, for example, when the humidity increases, the adhesion of the particles to the substrate becomes stronger,
There is a problem that stable display characteristics cannot be obtained.

Further, although electrodes are provided on the display substrate and the non-display substrate, respectively, there is a problem that the deterioration of these electrodes becomes remarkable when the humidity becomes high.

In order to solve the above-mentioned problem, it is conceivable to provide a seal member so that the space in which the particles are enclosed is not affected by the humidity of the outside world. However, deterioration of the sealing effect is expected due to deterioration of the sealing member over time, impact, and the like, and if the sealing effect is decreased, it is affected by humidity.

Further, when stable display characteristics cannot be obtained due to the influence of humidity, it is necessary to periodically replace with a new one. However, in the conventional image display medium, the space in which the particles are enclosed is changed. Since the humidity is unknown, there is a problem that it is not possible to determine the optimum replacement time. Furthermore, when the image display medium is large, there is a problem that it takes time and cost to replace it.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an image display medium capable of improving maintainability and obtaining stable display characteristics for a long period of time.

[0011]

In order to achieve the above object, the invention of claim 1 is directed to a display substrate having a first electrode arranged on the image display surface side, and a second electrode facing the display substrate. A non-display substrate having: a voltage applying unit for applying a predetermined voltage between the first electrode and the second electrode; and a voltage applying unit provided at a peripheral portion of the display substrate and the non-display substrate. Holding the display substrate and the non-display substrate at a predetermined distance, and sealing means for forming a predetermined closed space between the display substrate and the non-display substrate, and sealed in the closed space,
A group of particles that can move between the first electrode and the second electrode by an electric field generated by a voltage applied by the voltage applying unit; a humidity detecting unit that detects the humidity of the closed space; and the humidity. Monitoring means for monitoring the humidity of the closed space based on the humidity detected by the detecting means.

According to the invention of claim 1, the display substrate arranged on the image display surface side has the first electrode, and the non-display substrate facing the display substrate has the second electrode. . Since the display substrate and the non-display substrate each have an electrode, by applying a voltage between the electrodes, an electric field can be generated between the electrodes, that is, between the substrates. Further, a sealing means is provided in the peripheral portion between the display substrate and the non-display substrate, and the sealing means holds the display substrate and the non-display substrate at a predetermined interval, and the display substrate and the non-display substrate are separated from each other. A predetermined closed space is formed between them. A so-called spacer can be used as the sealing means, and a seal member can be provided in addition to the spacer. A particle group is enclosed in the formed closed space. In addition, in the particle group, a predetermined voltage is applied between the first electrode and the second electrode by a voltage application unit, and an electric field generated by the voltage causes the first electrode and the second electrode to be separated from each other. It is possible to move between. Further, the humidity detecting means detects the humidity of the closed space, and the monitoring means monitors the humidity of the closed space based on the humidity detected by the humidity detecting means. As the monitoring means, an informing means for informing the humidity detected by the humidity detecting means, a recording means for recording the detected humidity, a determining means for determining whether or not the detected humidity exceeds or does not exceed a predetermined value, etc. Can be applied. In this way, by detecting the humidity of the enclosed space in which the particles are enclosed, the humidity of the space can be grasped. And
It is possible to monitor the invasion of moisture from the outside due to deterioration of the sealing means or the like, and determine the optimum replacement time of the image display medium.

According to a second aspect of the present invention, in the image display medium according to the first aspect, the monitoring means dehumidifies the space when the humidity detected by the humidity detecting means exceeds a predetermined value. It is characterized by being a dehumidifying means.

According to the second aspect of the invention, in the image display medium, as an example of the monitoring means, the dehumidifying means for dehumidifying the space when the humidity detected by the humidity detecting means exceeds a predetermined value is applied. The humidity of the sealed space is preferably within a range in which the image display medium can exhibit stable display characteristics, and although the suitable humidity varies depending on the applied particles, specifically, it is generally about 60% or less. Is preferred.

According to a third aspect of the present invention, a display substrate arranged on the image display surface side and having a first electrode, a non-display substrate facing the display substrate and having a second electrode, and the first electrode are provided. A voltage applying means for applying a predetermined voltage between the second electrode and a peripheral portion of the display substrate and the non-display substrate, the display substrate and the non-display substrate at a predetermined interval. A sealing means for holding and forming a predetermined closed space between the display substrate and the non-display substrate; and an electric field generated by a voltage applied by the voltage applying means, which is enclosed in the closed space, And a dehumidifying means for dehumidifying the closed space, and a group of particles movable between the electrode and the second electrode.

According to the third aspect of the present invention, the display substrate arranged on the image display surface side has the first electrode, and the non-display substrate facing the display substrate has the second electrode. . Since the display substrate and the non-display substrate each have an electrode, by applying a voltage between the electrodes, an electric field can be generated between the electrodes, that is, between the substrates. Further, a sealing means is provided in the peripheral portion between the display substrate and the non-display substrate, and the sealing means holds the display substrate and the non-display substrate at a predetermined interval, and the display substrate and the non-display substrate are separated from each other. A predetermined closed space is formed between them. A particle group is enclosed in the formed closed space. Incidentally, the particle group, by the voltage applying means,
A predetermined voltage is applied between the first electrode and the second electrode, and an electric field generated by the voltage is movable between the first electrode and the second electrode. This closed space is dehumidified by the dehumidifying means. In this way, the dehumidifying means dehumidifies the closed space in which the particles are enclosed, so that the closed space can be kept at a low humidity. Then, by keeping the humidity low, it is possible to prevent the change in the charged state of the particles due to the humidity change, for example, to prevent the problem that the high adhesion of the particles to the display substrate due to high humidity. You can

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) The image display medium of the present invention comprises a plurality of display elements 10. FIG. 1 shows a schematic sectional configuration of a display element 10 which constitutes this image display medium. The display element 10 shown in FIG.
2 and the non-display substrate 14 facing the display substrate 14. A spacer 16 as a sealing means is provided between the display substrate 12 and the non-display substrate 14 of the display element 10, and a seal member 22 is provided on the outer peripheral portion of the spacer 16. Further, a humidity detecting device 24 for detecting the humidity in the closed space 18 described later is provided at a predetermined position between the spacer and the seal member 22.

The display substrate 12 is formed by the spacers 16.
And the non-display substrate 14 are arranged at a predetermined interval, and the display substrate 12, the non-display substrate 14, the spacer 16 and the seal member 22 form a closed space 18. Then, a particle group consisting of white particles 30 and black particles 32 is enclosed in this space.

The display substrate 12 comprises a transparent substrate 12a, a transparent electrode 12b and a dielectric film 12c. Specifically, a solution of 5 parts by weight of a polycarbonate resin in 45 parts by weight of monochlorobenzene was dip-coated on the conductive surface of a transparent glass electrode (2 mm) formed by sputtering an ITO electrode, and the polycarbonate film (5
μm) is formed. A glass substrate may be used as the transparent substrate 12a, or a transparent plastic substrate such as a polycarbonate resin, an acrylic resin, a polyimide resin, or a polyester resin may be used. For the transparent electrode 12b, oxides of indium, tin, cadmium, antimony, etc., and complex oxides thereof, or Au, A
A single layer film of g, Cu, C, Ni, etc., a mixed film or a composite film is usually 100 to 2 by the vapor deposition method or the sputtering method.
A material having a thickness of 000 angstroms or a known material of an organic conductive material such as polypyrrole or polythiophene can be applied. The transparent electrode 12b may be formed as a desired electrode pattern or a matrix electrode wholly or partially as in the conventional liquid crystal display element.
Further, depending on the charging characteristics of the particles that also enclose the dielectric film, polycarbonate, polyester, polyimide, epoxy, polyisocyanate, polyamide, polyvinyl alcohol, polybutadiene, PMMA, copolymer nylon, UV curable acrylic resin, amorphous Teflon (registered trademark) However, the present invention is not limited to these.

Similarly, the non-display substrate 14 includes the substrates 14a,
It is composed of an electrode 14b and a dielectric film 14c. Specifically, the non-display substrate 14 is prepared by, for example, forming spacers 16 described later on the electrodes, and then, for example, 45 parts by weight of monochlorobenzene on the electrode surface of the epoxy electrode substrate in which a copper electrode is attached to an epoxy substrate (5 mm). A solution obtained by dissolving 5 parts by weight of a polycarbonate resin is dip-coated and dried to form a polycarbonate film (5 μm). Electrode 14b
Can be formed as a desired electrode pattern or matrix electrode in whole or in part by a conventionally known means such as etching of a printed board. In addition, the transparent electrode 12 of the display substrate 12 is used as the electrode 14b of the non-display substrate 14.
The same thing as b may be applied.

Then, the electrode 14b of the non-display substrate 14 is
It is grounded, and the transparent electrode 12b of the display substrate 12 is connected to the voltage applying device 20.

A dry photo film resist can be applied to the spacer 16. Specifically, the dry photoresist is irradiated with ultraviolet light in an arbitrary pattern,
By developing, it is possible to accurately form a spacer having an arbitrary shape at an arbitrary height. The dry film resist is composed of a photopolymerizable layer, a support layer and, if necessary, a protective layer. The dry film resist is known to be of the alkaline development type or the solvent development type in the development mode, and both are applicable in the present invention. The film thickness is 50 ~
The one with 300 μm is used.

A thermoplastic resin can be applied to the seal member 22. Specifically, an epoxy resinous resin,
A thermosetting resin, a UV curable resin, a thermoplastic resin, or an air-permeable resin can be applied. The above-mentioned epoxy resin may be either one-component type or two-component type, and in the case of two-component type, 400 mmHg after kneading two adhesive components
It is necessary to remove air bubbles by degassing for 15 to 30 minutes at the following vacuum degree. Further, these epoxy resins may have any of room temperature curability and UV curability.
By these, between the display substrate and the non-display substrate, that is,
The airtightness of the closed space 18 can be maintained. Further, these resins can be supplied by screen printing or dispenser.

Besides, a mixture of a modified acrylate oligomer and an epoxy oligomer can be used. It is also possible to use an ultraviolet-curable acrylic adhesive, and as a specific example, an ultraviolet-curable acrylic resin, particularly one containing an acrylic monomer or an acrylic oligomer that is polymerized and cured by ultraviolet irradiation, is preferable.

Other resins applicable to the seal member 22 are as follows. Urethane resin, epoxy resin,
Acrylic resin, acrylic ester resin, phenoxy ether cross-linking resin, melamine resin, phenol resin, silicone resin, phenol resin, silicone resin, xylene resin, guanamine resin, diallyl phthalate resin,
At least one selected from the group consisting of vinyl ester resin, polyimide, maleic acid resin, unsaturated polyester resin, and alkyd resin, or a copolymer or mixture thereof is preferable.

Further, preferred application examples of the ultraviolet curable resin, the electron beam curable resin and the thermosetting resin will be given. UV curable resins include epoxy acrylate, urethane acrylate, polyester acrylate, polyfunctional acrylate, polyether acrylate, silicon acrylate, polybutadiene acrylate, unsaturated polyester / styrene, polyene / thiol, polystyryl methacrylate, UV curable lacquer and these. Copolymers and mixtures thereof are preferred.

The electron beam curable resins include epoxy acrylate, urethane acrylate, polyester acrylate, polyfunctional acrylate, polyether acrylate, silicon acrylate, polybutadiene acrylate, unsaturated polyester / styrene, polyene / thiol, polystyryl methacrylate, UV. Cured lacquers and their copolymers and mixtures are preferred.

As the thermosetting resin, epoxy resin, xylene resin, guanamine resin, diallyl phthalate resin, polyurethane, vinyl ester resin, unsaturated polyester, polyimide, melamine resin, maleic acid resin,
A urea resin, an acrylic resin, a silicon resin, an alkyd resin and copolymers and mixtures thereof are preferable.

As the thermoplastic resin, polypropylene,
Polyolefin such as polyethylene and ethylene-propylene copolymer, polyester, polyamide, ionomer, polyvinyl acetate, ethylene vinyl acetate copolymer, acrylic resin such as acrylic acid ester and methacrylic acid ester, polyvinyl acetal, phenol, modified epoxy Resins, amorphous polyesters and their copolymers and mixtures are preferred. Needless to say, a mixture of a thermosetting resin and an ultraviolet curable resin may be used as a curing resin, or a mixture of different types of resins may be applied.

As the air-permeable resin, acrylonitrile component, vinyl alcohol component, vinyl butyral component,
Among the cellulose-based component, the aramid component and the vinylidene halide component, a polymer containing at least one component in an amount of 60 mol% or more, or a mixture thereof is preferable.

Examples of the acrylonitrile component polymer include polyacrylonitrile and polyacrylonitrile-butadiene copolymer. Examples of the vinyl alcohol component polymer include polyvinyl alcohol. Examples of the vinyl butyral component polymer include polyvinyl butyral and a mixture of polyvinyl butyral and an epoxy resin.

As the vinylidene halide component polymer, PVDC (polyvinylidene chloride), PVDC-VC copolymer, PVDC-acrylonitrile copolymer, PVDC
-Acrylic ester copolymer or multi-component copolymer containing several monomers copolymerizable with vinylidene chloride, P
Examples include TFE.

As the anchor coating agent, one selected from the group consisting of polyurethane, polyamide, polyethyleneimine, amorphous polyester, hydrophilic polyester, ionic polymer complex, alkyl titanate resin, or a copolymer or mixture thereof is used. In addition, a polymerization initiator chain transfer agent, a photosensitizer, a dye, a cross-linking agent and the like can be appropriately used in combination as optional components.

To the white particles 30, fine powder of titania treated with isopropyltrimethoxysilane was added and mixed,
By frictional charging with the black particles 32, it is charged to a proper negative polarity. The average charge amount of the white particles 30 was −16 fC, and the average charge amount of the black particles 32 was +16 fC. The substrate inner dielectric layers 12c and 14c at this time are made of polycarbonate resin (PC-Z). The material of the inner surface of the substrate has a great influence on the charging polarity of the particles, so it must be selected appropriately. The above-mentioned fine powder of titania treated with silane has the function of suppressing the chargeability of the particles to an appropriate level that is not too high, and maintaining the fluidity of the particles at a high level.

The addition amount of the fine powder of titania treated with silane is appropriately adjusted in consideration of the particle size of the particles and the particle size of the fine powder. If the addition amount is too large, fine powder liberated from the surface of the white particles 30 is generated and adheres to the surface of some of the second particles, and the white particles 30 and the black particles 32 have the same charge polarity, Since it moves in the same direction as the electric field, it is not preferable. The amount of the titanium compound varies depending on the particle size of the particles and the like, but is 0.05-1.
It is 0 part by weight, more preferably 0.1 to 0.5 part by weight.

Further, these particles are affected by humidity, and charge-up occurs in a low-humidity environment, and charge escape occurs in a high-humidity environment. In addition, these charging characteristics change depending on the type of particles to be combined, the mixing ratio of particles, and the presence or absence of external addition treatment.
It is necessary to maintain the optimum humidity depending on the particle pair.

Further, since the shape of the particles used in this embodiment is a true sphere, the contact between the particles is almost point contact, and the contact between the particles and the inner surface of the substrate is also almost point contact. Van der Wal between the substrate and the inner surface of the substrate
The adhesive force based on the Is force is small. Therefore, the electric field allows the charged particles to move smoothly in the substrate. However, also here, when the humidity inside the substrate increases, the adhesive force between the particles and between the particles and the inner surface of the substrate increases due to the liquid bridging force, and it is necessary to prevent the increase in humidity for stable display.

As the fine powder to be mixed with the particles, silicon oxide (silica), titanium oxide, etc. are known. These are modified by reacting and drying a silane compound, a silane coupling agent, or silicone oil to adjust the positive and negative chargeability, fluidity, environment dependence, and the like. Well-known hydrophobic silica and hydrophobic titanium oxide can be used. In particular, a titanium compound obtained by reacting TiO (OH) ₂ described in JP-A-10-3177 with a silane compound such as a silane coupling agent is suitable.

This titanium compound is produced by reacting TiO (OH) ₂ produced in a wet process with a silane compound or silicone oil and drying. Since it does not pass through the firing process of several hundred degrees, strong bonds between Ti are not formed, there is no aggregation, and the particles are in the state of almost primary particles. Furthermore, since the silane compound or the silicone oil is directly reacted with TiO (OH) ₂ , the treatment amount can be increased, the charge can be controlled depending on the treatment amount of the silane compound, and the chargeability that can be imparted is the same as in the conventional case. This is a significant improvement over titanium oxide.

Here, as the silane compound, any of chlorosilane, alkoxysilane, silazane, and special silylating agent can be used. Examples of the silicone oil include dimethyl silicone oil, alkyl-modified silicone oil, α-methylsulfone-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, amino-modified silicone oil and the like.

As the white particles 30, in addition to the spherical fine particles of titanium oxide-containing crosslinked polymethylmethacrylate (MBX-White manufactured by Sekisui Plastics Co., Ltd.), spherical fine particles of crosslinked polymethylmethacrylate (Soken Chemical Co., Ltd.) are used.
CHEMISNOW MX) made by adding fine powder of titanium oxide pigment to the spherical fine particles and immobilizing them on the surface of fine particles by impacting the spherical fine particles with styrene resin, phenol resin, silicone resin, Examples include particles in which fine powder of white pigment is attached to or embedded in the surface of mother particles made of various materials such as glass. Spherical fine particles of crosslinked polymethylmethacrylate (Chemi Snow MX manufactured by Soken Chemical Industry Co., Ltd.) are monodisperse and have uniform particle diameters, each particle has uniform chargeability, and the threshold value of particle movement with respect to an electric field becomes sharper. At the same time, high contrast is obtained. Examples of the white pigment include titanium oxide, magnesium oxide, zinc oxide and the like.

The white particles also include porous sponge-like particles enclosing air and hollow particles. Also,
Also included are toners used in copying machines and printers, especially spherical particles produced by a wet method such as a polymerization method or a suspension method.

The black particles 32 are spherical fine particles of the above-mentioned cross-linked polymethylmethacrylate (Sekisui Plastics Co., Ltd.).
MBX-Black manufactured by Sekisui Chemical Co., Ltd. (Micropearl BB, Micropearl BB manufactured by Sekisui Chemical Co., Ltd.)
P), fine particles of amorphous carbon obtained by firing phenol resin particles (Unibex GCP manufactured by Unitika), and spherical fine particles of carbon and graphite (Nika beads ICB, Nica beads MC, Nica beads PC manufactured by Nippon Carbon Co., Ltd.).

Furthermore, in addition to white and black particles,
Colored particles such as red, blue, green, magenta, cyan, yellow, gold and silver can be used. For example,
Spherical fine particles of crosslinked polymethylmethacrylate (MBX-Red manufactured by Sekisui Plastics Co., Ltd.) and fine particles of crosslinked copolymers containing divinylbenzene as a main component are electroless nickel plated and then gold displacement plated. Conducted spherical conductive particles (Micropearl A manufactured by Sekisui Chemical Co., Ltd.)
U (trade name) etc. Also included are toners used in copying machines and printers, especially spherical particles produced by a wet method such as a polymerization method or a suspension method.

In the present embodiment, the humidity detecting device 24 includes a humidity indicator paper (SUTERLANDO COMPANY).
HUMIDITY INDICATOR made by spacer 1
Install in parallel with 6. In addition, a so-called humidity sensor can be applied as the humidity detection device 24. Specifically, the humidity sensors listed below can be applied. First, it is possible to apply an electric resistance type humidity sensor which is a method of detecting relative humidity by utilizing the fact that the impedance of the sensor element changes depending on the amount of water in the moisture sensitive film. Further, it is also possible to apply a capacitance-type sensor that measures relative humidity by sandwiching a moisture-sensitive film with a pair of electrodes and measuring a capacitance value that changes depending on the amount of water content. Furthermore, an electromagnetic wave absorption type sensor that knows the amount of water in the air from the attenuation state of the electromagnetic wave that changes depending on the amount of water in the moisture sensitive film can be applied. Furthermore, a heat conduction application type sensor that knows the amount of water in the air by utilizing the difference in heat conductivity due to the difference in absolute humidity in air can be applied. In addition, a dry and wet bulb type sensor that obtains the relative humidity from the humidity difference of the dry and wet bulb, a crystal oscillator type sensor that takes out the weight change of the hygroscopic film applied to the crystal oscillator as the change of the oscillation frequency, cobalt (II) chloride It is possible to apply a color-dependent hygrometer or the like that causes a color change depending on the degree of atmospheric humidity of paper that has been subjected to chemical processing such as hexahydrate.

Various dehumidifying methods described below can be considered as means for removing water in the air. Cooling dehumidification method that cools air below the dew point to remove condensed moisture, compression dehumidification that compresses moist air and cools it to separate moisture, and solid moisture absorbent with fine holes on the surface such as silica gel and zeolite. Solid adsorption dehumidification method that adsorbs water by capillary action, chemical reaction dehumidification method that removes water by chemically reacting with water in the air such as quick lime and combining with water molecules to form a new compound Use a substance that dissolves when it absorbs moisture in the air, such as a compound of calcium or magnesium chloride, and after making it into an aqueous solution, hold it by using a special membrane that allows gas to pass but does not pass liquid, or water in a polymer absorber. A hygroscopic dehumidifying method of adsorbing and holding to remove water can be used.

Hereinafter, driving of particles in the image display medium of this embodiment will be described. FIG. 2 illustrates a display state of the display element 10 related to the image display medium.
In FIG. 2A, a DC voltage of 200 V is applied to the display substrate 12, the white particles 30 move to the display substrate 12 side, and similarly, the black particles 32 move to the non-display substrate 14 side. . As a result, white display is performed on the display substrate 12 side.

In FIG. 2B, the voltage application is 0FF in FIG. 2A, the white particles 30 are held on the display substrate 12, and similarly, the black particles 32 are not displayed. It is held on the substrate 14. Then, white display is maintained on the display substrate 12.

FIG. 2C shows a DC voltage on the display substrate 12.
When 200 V is applied, the white particles 30 move to the non-display substrate 14 side, and similarly, the black particles 32 move to the display substrate 12 side. As a result, on the display substrate 12,
Displayed in black.

FIG. 2D shows the voltage applied to 0FF in FIG. 2C, the white particles 30 are held on the non-display substrate 14, and similarly, the black particles 32 are displayed. It is held on the substrate 12. A black display is maintained on the display substrate 12.

In such an image display medium as described above, by providing the humidity detecting device 24, the humidity can be regularly detected, and by detecting the humidity, the display element 10 constituting the image display medium can be detected. It is possible to grasp whether or not the closed space 18 maintains an appropriate humidity. As a result, it is possible to grasp the appropriate replacement time of the display element, and in some cases, to appropriately dehumidify, maintenance of the image display medium is facilitated, and stable display characteristics can be obtained for a long period of time. . (Second Embodiment) FIG. 3 is a schematic sectional view showing a display element 40 of an image display medium according to a second embodiment of the present invention. In the image display medium according to the present embodiment, the same parts as those in the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 3, the display element 40 constituting the image display medium includes the display substrate 12 and the non-display substrate 14 provided facing the display substrate 12, the display substrate 12 and the non-display substrate 1.
The spacer 16 is provided between the spacer 16 and the spacer 4, and the seal member 22 is provided so as to surround the spacer 16. The display substrate 12, the non-display substrate 14, and the spacer 16 form a closed space 18, and the closed space 18 is filled with white particles 30 and black particles 32. The display substrate 12 and the non-display substrate 14 have electrodes 12b and 1 respectively.
4b, and a voltage is applied between the electrodes 12b and 14b by a voltage applying device 20.

A humidity detecting device 24 is provided at a predetermined position between the spacer 16 and the seal member 22. A dehumidifying device 26 that dehumidifies the inside of the closed space 18 based on the detection result of the humidity detecting device 24 is provided outside the substrates 12 and 14 of the display element 40. A suction port 26a of the dehumidifying device 26 is provided in the vicinity of the humidity detecting device 24, and a cable for transmitting a signal as a detection result obtained from the humidity detecting device 24 is wired to the dehumidifying device 26 in the suction port 26a. Then, based on the obtained signal, the suction port 26
Excessive moisture in the closed space 18 is sucked from a to dehumidify the closed space 18.

The humidity detector 24 only needs to be able to detect the humidity of the closed space 18, and the display substrate 12 and the non-display substrate 14
It does not have to be installed between. Similarly, the dehumidifier 26 need only be able to dehumidify the moisture in the closed space 18, and does not have to be installed between the display substrate 12 and the non-display substrate 14.

The humidity detector 24 and the dehumidifier 26
Are provided on the substrate as follows. The dielectric 12c side of the display substrate 12 and the spacer 16 side (dielectric 14c side) of the non-display substrate 14 are overlapped and fixed by a clamp or a clip. After that, as the humidity detection device 24,
After sandwiching the electric resistance type humidity sensor, resin is injected into the gap between the display substrate 12 and the non-display substrate 14 using a dispenser and cured to form the seal member 22.

A through hole is formed in the non-display substrate 14, and the humidity detecting device 2 passes through the through hole.
The cable for transmitting the electric signal obtained from 4 is the dehumidifier 2
Wired to 6. The dehumidifying device 26 uses a cooling and dehumidifying method of cooling the air below the dew point and removing the condensed water.
The joint portion between the non-display substrate 14 and the dehumidifying device 26 is the display substrate 1
The seal member 22 is formed in the same manner as the gap between the non-display substrate 14 and the non-display substrate 14. The resin used for the seal member 22 is obtained in the same manner as in the first embodiment.

As described above, the humidity detecting device 24 detects the humidity in the closed space 18 and dehumidifies when the humidity deviates from the predetermined humidity range, thereby preventing high humidity from escaping to the high places. can do. As a result, maintenance of the image display medium is facilitated, and stable display characteristics can be obtained for a long period of time.

(Third Embodiment) FIG. 4 is a schematic sectional view showing a display element 50 of an image display medium according to a third embodiment of the present invention. In the image display medium according to the present embodiment, the same parts as those in the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, the display element 50 constituting the image display medium includes the display substrate 12 and the non-display substrate 14 provided facing the display substrate, and the display substrate 12 and the non-display substrate 1.
The spacer 16 is provided between the spacer 16 and the spacer 4, and the seal member 22 is provided so as to surround the spacer 16. The display substrate 12, the non-display substrate 14, and the spacer 16 form a closed space 18, and the closed space 18 is filled with white particles 30 and black particles 32. The display substrate 12 and the non-display substrate 14 have electrodes 12b and 1 respectively.
4b, and a voltage is applied between the electrodes 12b and 14b by a voltage applying device 20.

A dehumidifying device 26 for dehumidifying the inside of the closed space 18 is provided outside the substrates 12 and 14 of the display element 40. Through holes 2 are provided at predetermined locations on the non-display substrate 14.
7 is formed, and the closed space 18 is formed from the through hole 27.
Excessive moisture inside is sucked in to dehumidify the inside of the closed space 18.

The dehumidifying device 26 is provided as follows. First, the dielectric side of the display substrate 12 and the spacer 16 side (dielectric side) of the non-display substrate 14 are overlapped and fixed by a clamp or a clip. After that, resin is injected into the gap between the display substrate 12 and the non-display substrate 14 using a dispenser and cured to form the seal member 22. Further, the non-display substrate 14 is formed with through holes 27 for dehumidifying. The dehumidifying device 26 used a cooling and dehumidifying method of cooling the air below the dew point and removing the condensed water. The bonding portion between the non-display substrate 14 and the dehumidifying device 26 is similar to the gap between the display substrate 12 and the non-display substrate 14 in the sealing member 22.
Is formed. Also, dehumidification may be performed regularly,
You may go irregularly.

By dehumidifying the closed space 18 in this way, it is possible to prevent the closed space 18 from having high humidity, and to prevent the escape of the electric charge of the particles due to the high humidity. Therefore, maintenance of the image display medium is facilitated.

[0064]

As described above, according to the present invention, there is an excellent effect that it is possible to provide an image display medium which has improved maintainability and can obtain stable display characteristics for a long period of time. is there.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an image display medium according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing driving of particles of the image display medium according to the exemplary embodiment of the present invention.

FIG. 3 is a sectional view showing a schematic configuration of an image display medium according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a schematic configuration of an image display medium according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a schematic configuration of a conventional image display medium.

[Explanation of symbols]

10 Display element 12 Display board 12b electrode 14 Non-display board 14b electrode 16 spacers 18 closed space 20 Voltage application device 22 Seal member 24 Humidity detector 26 Dehumidifier 30 white particles 32 black particles 40 display elements 50 display elements

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor K. Suwabe             430 Sakai, Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture             Kunakai Fuji Xerox Co., Ltd. (72) Inventor Yoshiro Yamaguchi             430 Sakai, Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture             Kunakai Fuji Xerox Co., Ltd. (72) Inventor Yoshinori Machida             430 Sakai, Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture             Kunakai Fuji Xerox Co., Ltd. (72) Inventor Ken Matsunaga             430 Sakai, Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture             Kunakai Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. A display substrate arranged on the image display surface side and having a first electrode, a non-display substrate facing the display substrate and having a second electrode, the first electrode and the second electrode. A voltage applying unit that applies a predetermined voltage between the display substrate and the non-display substrate,
A sealing unit that holds the display substrate and the non-display substrate at a predetermined distance and forms a predetermined closed space between the display substrate and the non-display substrate; A group of particles that can move between the first electrode and the second electrode by an electric field generated by a voltage applied by an applying unit, a humidity detecting unit that detects the humidity of the closed space, and the humidity detecting unit. An image display medium comprising: a monitoring unit that monitors the humidity of the closed space based on the humidity detected by the image display medium. 2. The image display according to claim 1, wherein the monitoring unit is a dehumidifying unit that dehumidifies the space when the humidity detected by the humidity detecting unit exceeds a predetermined value. Medium. 3. A display substrate arranged on the image display surface side and having a first electrode, a non-display substrate facing the display substrate and having a second electrode, the first electrode and the second electrode. A voltage applying unit that applies a predetermined voltage between the display substrate and the non-display substrate,
A sealing unit that holds the display substrate and the non-display substrate at a predetermined distance and forms a predetermined closed space between the display substrate and the non-display substrate; An image including a group of particles that can move between the first electrode and the second electrode by an electric field generated by a voltage applied by an applying unit, and a dehumidifying unit that dehumidifies the closed space. Display medium.