JP2001034200A - Image display medium, image display method, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display medium capable of being rewriten in multi-color (two or more colors), and simpler in configuration, low in cost and high in resolution, and to provide a method and a device for displaying an image by which the image is displayed on the image display medium. SOLUTION: Voltage is applied on a transparent electrode ITO on a first substrate 20 while the medium is exposed to red light by an exposing means 16 through the first substrate 20 based on the image data. By exposure, magenta particles 24 are electrified into positive charges and move in the direction to the second substrate 18 so that the magenta particles 22 appear with white insulating particles 26 as the background along the exposure pattern based on the image data. Further, by applying the voltage on the transparent electrode ITO on the first substrate while exposing the medium to green light based on the image data, cyan particles 22 appear with the white insulating particles 26 as the background along the exposure pattern based on the image data.

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, an image display method, and an image display device. More specifically, the present invention relates to an image display medium which can be repeatedly rewritten in color by exposure and application of voltage, and this image display The present invention relates to an image display method for displaying an image on a medium and an image display device.

[0002]

2. Description of the Related Art Conventionally, a Twisting Ball Display has been used as a sheet-like image display medium that can be repeatedly rewritten.
(Two-color separate particle rotation display), electrophoresis, magnetophoresis,
Display technologies such as a thermal rewritable medium and a liquid crystal having memory properties have been proposed. Among the display technologies, thermal rewritable media, memory liquid crystal, etc. are excellent in the memory properties of an image, but the display surface cannot be sufficiently white-displayed like paper, and therefore, when an image is displayed. ,
There is a problem that it is difficult to visually confirm the distinction between a portion where an image is displayed and a portion where no image is displayed, that is, the image quality is deteriorated. In addition, display technology using electrophoresis and magnetophoresis,
It is a technology that has memory properties of an image and color particles are dispersed in a white liquid, so it is excellent in white display, but black (color) display that forms an image display portion is always in the gap between the colored particles. There is a problem in that the white liquid enters and the image becomes grayish, resulting in poor image quality. Also, since the white liquid is sealed inside the image display medium, the white liquid leaks out of the image display medium when the image display medium is removed from the image display device and handled roughly like paper. There is a risk. Further, Twisting Ball Display also has display memory properties, and oil exists only in cavities around particles inside the image display medium, but since it is almost in a solid state, sheeting is relatively easy. However, even if hemispheres painted white are completely aligned with the display side,
Light rays that enter the gap between the spheres are not reflected and are lost inside. Therefore, there is a problem that a white display with 100% coverage cannot be performed in principle, and the color becomes slightly gray. In addition, since the particle size is required to be smaller than the pixel size, it is necessary to manufacture fine particles with different colors for high-resolution display, which requires advanced manufacturing technology. There is also a problem.

On the other hand, as a display technique for solving the above-mentioned problems, a display technique using toner is used. A conductive colored toner and white particles are sealed between opposing electrode substrates, and the electrode inner surface of a non-display substrate is sealed. Injecting charge into the conductive coloring toner through the provided charge transport layer, the charged conductive coloring toner moves to the display substrate side located opposite to the non-display substrate by an electric field between the electrode substrates, A display technique has been proposed in which a conductive colored toner adheres to the inside of a substrate on the display side to display an image by contrast between the conductive colored toner and white particles. The present display technology is excellent in that the image display medium is entirely formed of a solid, and 100% can be switched in principle between white and black (color) display. However, the above technology is a display technology that obtains good two-color contrast in principle. In order to perform multicolor display of two or more colors, pixels divided into segments such as CMY and RGB are individually driven. Must be displayed. Such pixel division has the problem that the display resolution is reduced to 1/3 even with the same number of pixels, the medium configuration is complicated, and the device is complicated because each color segment is individually driven. . Further, this causes a problem that the cost of the image display medium and the image display device is increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a simpler configuration and is capable of repetitively rewriting multiple colors (two or more colors) with low cost and high resolution. It is an object to provide a display medium, an image display method for displaying an image on the image display medium, and an image display device.

[0005]

According to another aspect of the present invention, there is provided an image display medium, comprising: a pair of substrates; and a charge transporting electron or hole disposed between the pair of substrates. A first particle group including a transport material and a charge generation material that generates electrons and holes by light irradiation, and an insulating second particle group having a different color from the first particle group;
And the first particle group is composed of a plurality of types of particles, each of which is charged by irradiation with light of a different wavelength, and of a different color.

According to the present invention, since the first particle group in the light irradiation area is selectively charged by light irradiation and moved in accordance with an electric field, an image can be displayed. Since no electrode is required, the image display medium can have a simple configuration, and the manufacturing cost can be kept low. Further, since the matrix electrode and the pixel electrode are not used, the resolution of the image is not restricted by the electrode resolution, and a high-resolution display which is not restricted by the electrode resolution can be realized. Furthermore, since it is constituted by the particle groups of different colors, multi-color display is possible.

According to the present invention, the first particle group may include a magenta color particle charged by red and blue light, a cyan color particle charged by green and blue light, Further, it can be constituted by yellow particles charged by green and red light. According to the present invention, each of the cyan, magenta, and yellow particles can be selectively charged by light irradiation and moved by application of an electric field to display an image, thereby enabling full-color display of the image. Become.

Further, according to the present invention, the first particle group may be a particle reflecting green light charged by red and blue light, and a red particle charged by blue and green light. It can also be composed of particles that reflect light and particles that reflect blue light charged by red and green light.

According to a fourth aspect of the present invention, in the image display medium, electrons and holes are generated by a pair of substrates, a hole transporting material disposed between the pair of substrates, and a hole transport material for transporting holes. A first particle group including a charge generation material, an electron transport material for transporting electrons of a different color from the first particle group, and a second particle including a charge generation material for generating electrons and holes by light irradiation And comprising a group,
One of the first particle group and the second particle group may be charged by irradiation with light of different wavelengths, and may be formed of a plurality of types of particles of different colors.

According to the present invention, the first particle group and the second particle group can be charged to the opposite polarities and can be moved to the substrate in the opposite direction by the electric field. It can be good.

According to the present invention, one of the first particle group and the second particle group is defined as follows.
Magenta particles charged by red and blue light,
It can also be constituted by cyan particles charged by green and blue light and yellow particles charged by green and red light. According to the present invention,
Full-color display with good image display contrast can be performed.

Further, according to the present invention, one of the first particle group and the second particle group is
Reflects green and red light, particles that reflect green light, blue and green light, particles that reflect red light, and red and green light that reflects blue light It can also be constituted by particles that do.

An image display method for displaying an image on an image display medium according to any one of the first to sixth aspects is characterized in that an electric field is applied between a pair of substrates of the image display device. Is applied, and a plurality of lights having different wavelengths are selectively irradiated from one substrate side based on image data, whereby an image can be displayed.

Further, any one of claims 1 to 6
An image display device for displaying an image on an image display medium according to claim 7, wherein the image display medium according to any one of claims 1 to 6, and a pair of the image display medium An electric field applying means for applying an electric field to the substrate and a light irradiating means for irradiating one of the substrates of the image display medium with light based on image data can be provided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] An image forming apparatus 10 according to a first embodiment includes an image display medium 12, a voltage application unit 14, and exposure units 16a and 16b as shown in FIG. As shown in FIG. 2, the image display medium 12 includes a second substrate 18, a particle layer 19, and a first substrate 20 in this order from the display surface side. The first substrate 20 and the second substrate 18 are provided with a transparent electrode ITO as described later. The transparent electrode ITO of the second substrate 18 is grounded, and The transparent electrode ITO is a voltage applying means 14
Is connected to The exposure units 16a and 16b are arranged on the first substrate side of the image display medium 12.

Next, details of the image display medium 12 will be described. As the second substrate 18 and the first substrate 20 constituting the outside of the image display medium 12, a 7059 glass substrate with a transparent electrode ITO of 25 × 25 × 1.1 mm is used. 20 × 20 × 0.5
A central portion of the millimeter-sized silicon rubber plate is cut out into a square of 10 × 10 mm size to form a space, and this silicon rubber plate is placed on the second substrate 18. Cyan particles 22 containing a hole transport material and a charge generation material, magenta particles 24 containing a hole transport material and a charge generation material, and white insulating particles 26 having a particle size of 20 μm (Sekisui Fine Chemical Micro And Pearl SP-220) at a ratio of 1: 1: 1. About 10 milligrams of the mixed particles are shaken down into a square-cut space of the silicone rubber plate. Thereafter, the first substrate 20 is brought into close contact with the silicon rubber plate, the pressure between the first and second substrates is held by a double clip, and the silicon rubber plate and the first and second substrates are bonded to each other. Image display medium 12
To form

The cyan particles 22 and the magenta particles 24 were adjusted in the following procedure.

First, 100 parts by weight of a polyester resin, 2 parts by weight of benzimidazole perylene, 5 parts by weight of CI Pigment Blue 15: 3, 20 parts by weight of triphenylamine, and 110 parts by weight of ethyl acetate were used in a ball mill. Was dispersed for 48 hours to obtain a liquid A, and 100 parts by weight of a 2% aqueous solution of carboxymethylcellulose was adjusted to obtain a liquid B. Next, 100 parts by weight of the liquid B was stirred with an emulsifier, and 50 parts by weight of the liquid A was slowly added thereto to suspend the mixed liquid. Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain cyan particles 22. The average particle size of the particles was 10 μm. These particles have a property of being charged by irradiation of green light.

Next, magenta particles 24 are composed of 100 parts by weight of a polyester resin, 2 parts by weight of benzimidazole perylene, C.I. I. Pigment Red 57, 4 parts by weight, triphenylamine 20 parts by weight, and ethyl acetate 110 parts by weight were dispersed in a ball mill for 48 hours to obtain a liquid C. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted to obtain a liquid D. Next, 100 parts by weight of the liquid D was stirred by an emulsifier, and 50 parts by weight of the liquid C was slowly added thereto to suspend the mixed liquid. Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain magenta particles 24. The average particle size of the particles was 12 μm. These particles have a property of being charged by irradiation of red light.

Next, the operation of this embodiment will be described. The first substrate 2 is exposed by the exposure unit 16 based on the image data.
A voltage is applied to the transparent electrode ITO of the first substrate 20 while exposing with red light of 1 mW / cm2 from the 0 side. The magenta particles 24 are positively charged by the exposure and move toward the second substrate 18, so that the magenta particles 22 are converted into the white insulating particles 2 along the exposure pattern based on the image data.
6 appeared against the background. That is, a magenta image with a white background can be displayed on the image display medium 12. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV.

Further, based on the image data, the exposure means 1
In 6, a voltage is applied to the transparent electrode ITO of the first substrate 20 while exposing with 1 mW / cm 2 of green light from the first substrate 20 side. Upon exposure, the cyan particles 22 become positively charged,
Since the particles move in the direction of the second substrate 18, the cyan-colored particles 22 appear along the exposure pattern based on the image data with the white insulating particles 26 as a background. That is, a cyan image with a white background can be displayed on the image display medium 12. At this time, the first substrate 20
The voltage applied to the electrodes was 6 kV.

This image is maintained as it is by the intermolecular force between the magenta particles 24 and the cyan particles 22 and the first substrate 20 and the second substrate 18 even when the application of the electric field is stopped.

In the present embodiment, the cyan particles 22 and the magenta particles 24 are configured to include the hole transport material, but are configured to include the electron transport material, and the negative voltage is applied by applying a negative voltage. The image can also be displayed by moving to the second substrate 18 side.

Further, a charge transporting material for transporting holes or electrons, a charge generating material for generating holes and electrons,
The materials constituting the substrate 20 and the second substrate 18 and the insulating particles 26 are not limited to those described above, and the following materials may be used. In each of the embodiments described below, the following materials can be similarly used.

First, the white or black particles of the insulating particles include spherical particles (micropearl SP and micropearl BB manufactured by Sekisui Chemical Co., Ltd.) made of a crosslinked copolymer containing divinylbenzene as a main component, and crosslinked polystyrene. Fine particles of methyl methacrylate (MBX-20 black and white manufactured by Sekisui Plastics Co., Ltd.) and fine particles of polytetrafluoroethylene (Rublon L manufactured by Daikin Industries, Shamrock Tech
nologies Inc., SST-2) and silicone resin fine particles (Tospearl, Toshiba Silicone Co., Ltd.).

Among the charge transporting materials, benzoquinone-based, tetracyanoethylene-based,
Organic compounds such as tetracyanoquinodimethane, fluorenone, xanthone, phenanthraquinone, phthalic anhydride, diphenoquinone, and silane compounds, amorphous silicon, amorphous selenium, tellurium, selenium-tellurium alloy, cadmium sulfide, and sulfide Examples of the inorganic N-type semiconductor material include copper, nickel sulfide, antimony sulfide, zinc sulfide, zinc oxide, titanium oxide, zinc sulfide, and the like. Further, as the hole charge transporting substance, in the case of low molecular weight compounds, pyrene-based, carbazole-based, hydrazone-based, oxazole-based, oxadiazole-based, pyrazoline-based, arylamine-based, arylmethane-based, benzidine-based, thiazole-based, Stilbene-based, butadiene-based compounds and the like, and as the high molecular compound, poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin, ethyl Carbazole-formaldehyde resin, ethylcarbazole-
Formaldehyde resin, triphenylmethane polymer,
Organic compounds such as polysilane, amorphous silicon,
Examples include inorganic P-type semiconductors composed of amorphous selenium, tellurium, selenium-tellurium alloy, cadmium sulfide, copper sulfide, nickel sulfide, antimony sulfide, zinc sulfide, and titanium oxide.

Examples of the charge generating material include azo pigments such as bisazo pigments and trisazo pigments, quinone pigments, perylene pigments, indigo pigments, thioindigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, Quinoline pigments, lake pigments, azo lake pigments, anthraquinone pigments, oxazine pigments, dioxazine pigments, triphenylmethane pigments,
Various organic pigments and dyes such as azulenium dyes, squarium dyes, pyrylium dyes, triallylmethane dyes, xanthene dyes, thiazine dyes, cyanine dyes, and also amorphous silicon, amorphous selenium, tellurium, selenium -Tellurium alloy, cadmium sulfide, antimony sulfide, zinc oxide, titanium oxide, copper sulfide,
Examples include inorganic materials such as nickel sulfide and zinc sulfide.

As the binder resin, a high molecular polymer capable of forming an electrically insulating film is preferable. Examples of such a high molecular polymer include polycarbonate, polyester, methacrylic resin, acrylic resin, and polyvinyl chloride. , Polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile polymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicon -Alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole, polyvinylbutyral, polyvinylformal, polysulfone, casein, gelatin, polyvinyl alcohol, ethylcellulose, phenolic resin, polyphenol Examples thereof include lamide, carboxy-methylcellulose, vinylidene chloride-based polymer latex, and polyurethane. The binder resin is not limited to these, and these binder resins can be used alone or in combination of two or more. Further, additives such as a dispersion stabilizer, a plasticizer, a surface modifier, an antioxidant, and a light deterioration inhibitor can be used together with these binder resins.

Here, examples of the hole transport substance include hydrazone compounds, stilbene compounds, pyrazoline compounds, arylamine compounds and the like. Resins containing these can be used for the substrate. Examples of the electron transporting substance include a fluorenone compound, a diphenoquinone derivative, a pyran compound, and zinc oxide. Resins containing these can be used for the substrate.

Further, a self-supporting resin having a charge transporting property may be used for the substrate. As a result, bending, elongation, etc.
The structure can be made strong against external force applied to the image display medium 12.

As a self-supporting resin having such a charge transporting property, there is a charge transporting polymer. For example,
Polyvinylcarbazole, U.S. Pat. No. 4,806,44
Polycarbonate by polymerization of a specific dihydroxyarylamine and bischloroformate described in US Pat. No. 3,806,444; Polycarbonate by polymerization of a specific dihydroxyarylamine and phosgene described in US Pat. No. 4,806,444; Polycarbonate prepared by polymerization of bishydroxyalkylarylamine with bischloroformate or phosgene described in U.S. Pat. Nos. 4,937,165 and 4,952,801,517.
No. 9,288, a polycarbonate obtained by polymerization of a specific dihydroxyarylamine or bishydroxyalkylarylamine with bischloroformate, or a polyester obtained by polymerization of a bisacyl halide;
Arylamine polycarbonate having a specific fluorene skeleton described in U.S. Pat. No. 5,034,296,
Alternatively, polyesters, polyurethanes described in U.S. Pat. No. 4,983,482, polyesters having a specific bisstyrylbisarylamine as a main chain described in JP-B-59-28903, JP-A-61-20953, and JP-A-1-134456, JP-A-1-134457
JP, JP-A-1-134462, JP-A-4-4-1
No. 33065, JP-A-4-133066, and the like, wherein a polymer having a charge-transporting substituent such as hydrazone or triarylamine as a pendant is referred to as "The Sixth In".
ternational Congress on Advances in Non-impact Pri
nting Technologies, 306, (1990). "and a polymer having a tetraarylbenzidine skeleton.

Further, for example, a charge transporting polymer represented by the general formula (I-1) or (I-2) described in JP-A-8-253568 can be used [where Y is a divalent hydrocarbon group. And Z represents a divalent hydrocarbon group, and A represents a compound of the formula (I-3) (wherein R1 and R2 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a substituted amino group, or a halogen atom X represents a substituted or unsubstituted divalent aromatic group; n represents an integer of 1 to 5;
Represents 0 or 1), and B and B 'each independently represent a group -O- (YO) mH or a group -O- (YO) m-CO-Z —CO—OR ′ (where R ′ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, Y represents a divalent hydrocarbon group, and Z represents 2 M represents an integer of 1 to 5), m represents an integer of 1 to 5, and p represents an integer of 5 to 5000]. Further, X in the general formula (I-1) or (I-2) is
The charge transporting polymer represented by the structural formula (II) or (III) can be used.

[0034]

Embedded image

The conductive particles are capable of transferring electric charges by contact with a substrate. Such particles are, for example, particles of a metal such as carbon black, nickel, silver, gold, tin, or the like, or particles having these materials coated or contained on the particle surface.
Specifically, spherical conductive particles (micropearl NI manufactured by Sekisui Chemical Co., Ltd.) obtained by electroless nickel plating on the surface of fine particles composed of a crosslinked copolymer containing divinylbenzene as a main component.
(Trade name)) and then gold-plated spherical conductive particles (Micropearl AU manufactured by Sekisui Chemical Co., Ltd.)
(Product name)). In addition, spherical conductive particles of amorphous carbon obtained by carbonizing and curing a thermosetting phenol resin (Univex GC manufactured by Unitika Ltd.)
P, H-Type (trade name): Volume resistivity ≤10 ^-2 Ω · cm),
Further, spherical conductive particles coated with a metal such as gold and silver (Univex GCP (trade name) manufactured by Unitika Ltd.):
Volume specific resistance ≦ 10 ⁻⁴ Ω · cm), spherical conductive particles in which silica and alumina spherical oxide fine particles are coated with Ag and tin oxide on the surface (Admafine (trade name) manufactured by Admatex Co., Ltd.) Or particles obtained by attaching or embedding conductive fine powder to the surface of base particles made of various materials such as styrene resin, acrylic resin, phenol resin, silicone resin, polyester resin, and glass. Further, as particles of different colors, white or black colorless particles are included in addition to colored particles such as cyan, magenta, yellow, red, green, and blue. Examples of the white or black particles include spherical particles (micropearl SP and micropearl BB (trade name) manufactured by Sekisui Chemical Co., Ltd.) made of a crosslinked copolymer containing divinylbenzene as a main component, and fine particles of crosslinked polymethyl methacrylate (Sekisui Chemical). MBX-20 black and white (trade name) manufactured by Kaseihin Kogyo Co., Ltd., fine particles of polytetrafluoroethylene (Rublon L, Shamrock Technologies manufactured by Daikin Industries, Ltd.)
Inc. SST-2 (trade name)) and silicone resin fine particles (Tospearl manufactured by Toshiba Silicone Co., Ltd.).

As a material for forming the first substrate 20 and the second substrate 18, glass, plastic, or the like can be used. However, the material is excellent in flexibility close to paper hard copy and excellent in mechanical strength that can withstand rough handling. Therefore, it is desirable to use a plastic material. Examples of such a plastic substrate include a polyester film such as polyethylene terephthalate, polycarbonate, and polyimide. The thickness of the substrate is preferably about 75 μm to 500 μm in terms of self-supporting property, flexibility, light weight, thickness when stacked, and the like.

The method that can be used as a method for producing the particles containing the charge generating material and the charge transporting material in the present embodiment and each of the following embodiments is as follows.

A solution suspension method is known as one of the methods for producing particles. In the dissolution suspension method, an oil phase solution in which a resin such as polyester or styrene and a pigment are dissolved and dispersed in a solvent is mixed and suspended in an aqueous phase containing a water-soluble resin to form particles. It is a way to embody. A charge transport material, for example, an oil phase solution in which triphenylamine, a polyester resin, and a color pigment are dissolved and dispersed in a solvent is mixed and suspended in an aqueous solvent to form particles, and the solvent is removed to form a powder. The particles containing the transport material are obtained.

As the charge generation material and the charge transport material,
The above are available.

As the coloring agent, known organic or inorganic pigments and dyes and oil-soluble dyes can be used. For example, furnace black, carbon black such as channel black, red iron oxide, navy blue, inorganic pigments such as titanium oxide,
Azo pigments such as fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, and para brown; phthalocyanine pigments such as copper phthalocyanine and metal-free phthalocyanine; flavandron yellow; And condensed polycyclic pigments such as oxazine violet.

As the solvent used for adjusting the oil phase component, a general organic solvent can be used. For example, toluene,
Hydrocarbons such as xylene and hexane; halogenated hydrocarbons such as methylene chloride, chloroform and dichloroethane; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; esters such as methyl acetate, ethyl acetate and butyl acetate; acetone and methyl ethyl ketone And ketones such as cyclohexanone.

As the aqueous medium, water is mainly used, but a water-soluble solvent may be mixed and used. Further, it is preferable to add a dispersant in terms of particle size distribution.

The charge transporting material, charge generating material, binder resin and the like used in the present invention are not limited to those listed here, and may be used alone or in combination of two or more. Can also be used. Further, as the exposure means 16 constituting the image display device 10 according to the present embodiment, in addition to a light emitting device in which a surface light emitting device such as a CRT and a fiber optical system or an image forming optical system are combined, Use a one-dimensional optical writing device in which elements, fluorescent display tubes, plasma light emitting devices, EL light emitting devices, LED light emitting devices, etc. are arranged in a line, or a two-dimensional optical writing device in which the above-described elements are arranged in a plane. Can be. In addition, the above-mentioned exposure means, by a combination with a light emitting element or RGB filter that emits RGB light,
Exposure with color separation is possible. (Surface exposure apparatus: FIG. 9
Reference, linear exposure apparatus: see FIG. 8). In addition, an optical writing device (laser exposure device: see FIG. 10) in which each laser light source that oscillates RGB wavelengths is one-dimensionally or two-dimensionally scanned by a scanning optical system can be used. Also, instead of the digital exposure means as described above, a fluorescent light,
Decompose the wavelength of illumination light from a halogen lamp, etc.
Irradiation may be performed directly or through a reflecting or transmitting object, or an image may be formed by a lens.

According to the present embodiment, an image is displayed by applying an electric field and selectively irradiating a plurality of lights having different wavelengths from the first substrate 20 side based on image data. Therefore, it is not necessary to use a matrix electrode or a pixel electrode to display a multi-color (two or more colors) image, so that the image display medium and the image display device can have a simple configuration and can be manufactured at low cost. can do. Further, since the resolution of an image is not limited by the electrode resolution as in the case of using a matrix electrode or a pixel electrode, high-resolution display can be realized without being limited by the electrode resolution. Further, unlike the case where a matrix electrode or a pixel electrode is used, the number of electrical contacts between the image display medium and the drive circuit on the data transfer side is not required many, and only two contacts are required. The display medium can be easily detached from the image display device. Further, since the inside of the image display medium is made of only solid, there is no risk of liquid leakage, and the handling of the image display medium becomes easier as compared with the case where it is made of liquid.

[Second Embodiment] In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and only different parts will be described.

First, as described later, the cyan particles 32, the magenta particles 28, and the white particles 30 to be sealed in the particle layer 19 were adjusted in the following procedure.

First, the cyan particles 32 are adjusted by the following procedure.

100 parts by weight of polyester resin, 2 parts by weight of benzimidazole perylene, CI Pigment Blue 15: 3
5 parts by weight, n-type hydrogenated amorphous silicon carbide powder 1
0 parts by weight and 110 parts by weight of ethyl acetate were dispersed in a ball mill for 48 hours to obtain a liquid A. Meanwhile, carboxymethyl cellulose 2%
The aqueous solution was adjusted to 100 parts by weight to obtain solution B. Then B in the emulsifier
100 parts by weight of the liquid was stirred, and 50 parts by weight of the liquid A was slowly added thereto to suspend the mixture. Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing a cyan electron transporting material and a charge generating material. The average particle size is
It was 10 μm. These particles have a property of being negatively charged by irradiation of green and blue light.

Next, the magenta particles 28 were prepared in the following procedure.

100 parts by weight of a polyester resin, 2 parts by weight of benzimidazole perylene, C.I. I. Pigment Red 57, 10 parts by weight of n-type hydrogenated amorphous silicon carbide powder, and 110 parts by weight of ethyl acetate in a ball mill for 48 parts.
Time-dispersed to obtain a liquid C. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethylcellulose was adjusted to obtain solution D. Next, 100 parts by weight of the liquid D was stirred by an emulsifier, and 50 parts by weight of the liquid C was slowly added thereto to suspend the mixed liquid. Thereafter, the ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing a magenta hole transporting material and a charge generating material. The average particle size of the particles was 12 μm. These particles have a property of being negatively charged by irradiation of red and blue light.

Further, white particles 30 were prepared in the following procedure.

100 parts by weight of polyester resin, 20 parts by weight of triphenylamine, 10 parts by weight of zinc oxide powder, ethyl acetate
110 parts by weight was dispersed in a ball mill for 48 hours to obtain a liquid E. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted to obtain solution F. Next, 100 parts by weight of the liquid F was stirred with an emulsifier, and 50 parts by weight of the liquid E was slowly added thereto to suspend the mixed liquid. Thereafter, the ethyl acetate was removed under reduced pressure, washed with water,
After drying and classification, particles containing a white electron transporting material and a charge generating material were obtained. The average particle size of the particles was 10 μm.

As in the first embodiment, the second substrate 1
8, cyan particles 32, magenta particles 28, and white particles 3
About 10 milligrams of the mixed particles obtained by mixing 0 and 1 in a 1: 1 ratio are shaken off. Thereafter, the first substrate 20 is brought into close contact with the silicon rubber plate, and the image display medium 12 as shown in FIG. 3 is formed in the same manner as in the above-described embodiment.

Next, the operation of this embodiment will be described. The first substrate 2 is exposed by the exposure unit 16 based on the image data.
A voltage is applied to the transparent electrode ITO of the first substrate 20 while exposing with red light of 1 mW / cm2 from the 0 side. Exposure causes the magenta particles 28 to become negatively charged and
, The white particles 30 are positively charged and move in the direction of the first substrate 20, so that the magenta particles 28 become white particles 30 along the exposure pattern based on the image data. Appeared as a background. That is, a magenta image with a white background can be displayed on the image display medium 12. At this time, the voltage applied to the electrode of the first substrate 20 was minus 4 kilovolts.

Further, based on the image data, the exposure means 1
In 6, a voltage is applied to the transparent electrode ITO of the first substrate 20 while exposing with 1 mW / cm 2 of green light from the first substrate 20 side. The exposure causes the cyan particles 32 to be negatively charged and moves toward the second substrate 18, and the white particles 30 to be negatively charged and moves toward the first substrate 20. Along the exposed pattern, cyan particles 32 appeared against white particles 30 as a background.
That is, a cyan image with a white background can be displayed on the image display medium 12. At this time,
The voltage applied to the electrode of the first substrate 20 was -5 kV.

It should be noted that even if the application of the electric field is stopped, this image is caused by the intermolecular force between the magenta particles 28, the cyan particles 32 and the white particles 30 and the first substrate 20 and the second substrate 18. It is kept as it is.

According to this embodiment, the magenta particles 28, the cyan particles 32, and the white particles 30 can be charged to opposite polarities, and can be moved to the substrate in the opposite direction according to the electric field. Therefore, the display contrast of the image can be improved.

[Third Embodiment] In the third embodiment, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and only different parts will be described.

First, as described later, the cyan particles 34, the magenta particles 36, the yellow particles 38, and the white particles 40 to be sealed in the particle layer 19 were adjusted in the following procedure.

First, the cyan particles 34 are adjusted by the following procedure.

100 parts by weight of a polyester resin, 2 parts by weight of benzimidazole perylene, CI Pigment Blue 15: 3
5 parts by weight, triphenylamine 20 parts by weight, ethyl acetate 1
10 parts by weight was dispersed in a ball mill for 48 hours to obtain a liquid A. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethylcellulose was adjusted to liquid B. Next, 100 parts by weight of the liquid B was stirred with an emulsifier, and 50 parts by weight of the liquid A was slowly added thereto to suspend the mixed liquid. Thereafter, the ethyl acetate was removed under reduced pressure, washed with water,
The particles were dried and classified to obtain particles containing a cyan hole transporting material and a charge generating material. The average particle size of the particles was 10 μm.
These particles have a property of being positively charged by irradiation of green and blue light.

Next, the magenta particles 36 were adjusted in the following procedure.

100 parts by weight of a polyester resin, 2 parts by weight of benzimidazole perylene, C.I. I. Pigment Red 57 (5 parts by weight), triphenylamine (20 parts by weight), and ethyl acetate (110 parts by weight) were dispersed in a ball mill for 48 hours to obtain a liquid C.
On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethylcellulose was adjusted to obtain solution D. Next, 100 parts by weight of the liquid D was stirred by an emulsifier, and 50 parts by weight of the liquid C was slowly added thereto to suspend the mixed liquid. Thereafter, the ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing a magenta hole transporting material and a charge generating material. The average particle size of the particles was 10 μm. These particles have a property of being positively charged by irradiation of red and blue light.

Next, the yellow particles 38 were adjusted in the following procedure. 100 parts by weight of polyester resin, 2 parts by weight of benzimidazole perylene, C.I. I. Pigment
5 parts by weight of Yellow 12, 20 parts by weight of triphenylamine, and 110 parts by weight of ethyl acetate were dispersed in a ball mill for 48 hours.
Liquid. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted to obtain solution F. Next, 100 parts by weight of the liquid F was stirred with an emulsifier, and 50 parts by weight of the liquid E was slowly added thereto to suspend the mixed liquid. Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried, and classified to obtain particles containing a yellow hole transport material and a charge generation material. Average particle size is 10μ
m. These particles have a property of being positively charged by irradiation of red and green light.

As in the above-described embodiment, the second substrate 1
In the space of the silicon rubber plate provided on the surface 8, cyan particles 34, magenta particles 36, yellow particles 38, and white insulating particles 26 are in a one-to-one-to-one-to-three relationship.
Shake off about 10 milligrams of the mixed particles. Then, the first substrate 2 is placed on the silicon rubber plate.
The image display medium 12 as shown in FIG. 5 is formed in the same manner as in the above-described embodiment to form an image display device as shown in FIG.

Next, the operation of this embodiment will be described. 1 mW / cm from the first substrate 20 side based on the image data
2 is performed based on the image data, and the first substrate 2
When the voltage applied to the 0 electrode was gradually increased, the cyan particles 3 were formed on the second substrate 18 along the exposure pattern.
4 and magenta particles 36 appeared against the white insulating particles 26 as a background. The appearance of the image portion was blue due to the subtractive mixing of cyan and magenta. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV. Next, 1 mW / cm2 green exposure was performed from the first substrate 20 side based on the image data, and the voltage applied to the electrodes of the first substrate 20 was gradually increased. Along, cyan particles 34 and yellow particles 38 appeared against the white insulating particles 26 as a background. The appearance of the image area was green due to the subtractive mixing of cyan and yellow. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV. Further, the first substrate 20
When a red exposure of 1 mW / cm 2 was performed from the side based on the image data and the voltage applied to the electrodes of the first substrate 20 was gradually increased, the magenta particles 36 were formed on the second substrate 18 along the exposure pattern. And yellow colored particles 38 appeared against the background of the white insulating particles 26. The appearance of the image portion was red due to the subtractive color mixture of magenta and yellow.
At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV.

Note that the image displayed by the above-described procedure, even if the application of the electric field is stopped, is not affected by the magenta particles 36, the cyan particles 34, the yellow particles 38, and the first substrate 2.
It is held as it is by the intermolecular force between the zero and the second substrate 18.

According to the present embodiment, it is possible to selectively charge each of the cyan, magenta and yellow particles by irradiating light of different wavelengths, and to display an image by moving the particles by applying an electric field. Thus, full-color display of an image becomes possible. That is, it is possible to provide an image display medium and an image display device capable of performing full-color display with good contrast and capable of color reproduction using the same light absorbing substance as a hard copy.

[Fourth Embodiment] In the fourth embodiment, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and only different parts will be described.

First, the following purified liquid crystal polymer was prepared by the same method as that disclosed in JP-A-6-186534.

[0071]

Embedded image

Next, as described later, the blue particles 40, the green particles 42, and the red particles 44 to be sealed in the particle layer 19 were adjusted in the following procedure.

First, particles containing a hole-generating material and a charge-transporting material exhibiting blue selective reflection were prepared in the following procedure.

67 parts by weight of the polymer of the formula (1), 33 parts by weight of the polymer of the formula (2), 2 parts by weight of benzimidazole perylene, 20 parts by weight of triphenylamine and 110 parts by weight of ethyl acetate are dispersed in a ball mill for 48 hours. A solution was prepared. Meanwhile, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted, and B
Liquid. Next, 100 parts by weight of the liquid B was stirred with an emulsifier, and 50 parts by weight of the liquid A was slowly added thereto to suspend the mixed liquid.
Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing an electron transporting material exhibiting blue selective reflection and a charge generating material. The average particle size of the particles was 10 μm.
These particles have a property of being positively charged by irradiation of red and green light.

Next, green particles 42 containing a hole generating material and a charge transporting material exhibiting green selective reflection were prepared by the following procedure.

70 parts by weight of the polymer of the formula (1), 30 parts by weight of the polymer of the formula (2), 2 parts by weight of benzimidazole perylene, 20 parts by weight of triphenylamine and 110 parts by weight of ethyl acetate are dispersed in a ball mill for 48 hours. C solution. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted, and D
Liquid. Next, 100 parts by weight of the liquid D was stirred by an emulsifier, and 50 parts by weight of the liquid C was slowly added thereto to suspend the mixed liquid.
Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing an electron transporting material exhibiting blue selective reflection and a charge generating material. The average particle size of the particles was 10 μm.
These particles have a property of being positively charged by irradiation of red and blue light.

Next, particles containing a hole-generating material and a charge-transporting material exhibiting red selective reflection were prepared in the following procedure.

Disperse 72 parts by weight of the polymer of the formula (1), 28 parts by weight of the polymer of the formula (2), 2 parts by weight of benzimidazole perylene, 20 parts by weight of triphenylamine and 110 parts by weight of ethyl acetate in a ball mill for 48 hours. The solution was designated as solution E. On the other hand, 100 parts by weight of a 2% aqueous solution of carboxymethyl cellulose was adjusted, and F
Liquid. Next, 100 parts by weight of the liquid F was stirred with an emulsifier, and 50 parts by weight of the liquid E was slowly added thereto to suspend the mixed liquid.
Thereafter, ethyl acetate was removed under reduced pressure, washed with water, dried and classified to obtain particles containing an electron transporting material and a charge generating material exhibiting red selective reflection. The average particle size of the particles was 10 μm.
These particles have a property of being positively charged by irradiation of green and blue light.

As in the above-described embodiment, the second substrate 1
Mixed particles obtained by mixing blue particles 40, green particles 42, red particles 44, and black insulating particles 46 at a ratio of 1: 1: 1: 13 in the space of the silicon rubber plate provided on Shake off about 10 milligrams. Thereafter, the first substrate 20 is brought into close contact with the silicon rubber plate, and an image display medium 12 as shown in FIG. 7 is formed in the same manner as in the above-described embodiment, and an image display device as shown in FIG. Constitute.

Next, the operation of this embodiment will be described. 1 mW / cm from the first substrate 20 side based on the image data
The blue exposure of No. 2 was performed based on the image data, and the voltage applied to the electrodes of the first substrate 20 was gradually increased.
The green particles 42 are formed on the second substrate 18 along the exposure pattern.
And red particles 44 appeared against black particles 46 as a background. The appearance of the image portion was yellow due to additive mixing of green and red. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV. Next, green exposure of 1 mW / cm2 was performed from the first substrate 20 side based on the image data, and the voltage applied to the electrodes of the first substrate 20 was gradually increased. Along the pattern, blue particles 40 and red particles 44 appeared against black particles 46. The appearance of the image portion was magenta due to additive mixing of blue and red. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV. Further, red light exposure of 1 mW / cm2 was performed from the first substrate 20 side based on the image data, and the voltage applied to the electrodes of the first substrate 20 was gradually increased. Blue particles 40 and green particles 42 along the pattern
Appeared with black particles 46 as the background. The appearance of the image portion was cyan due to the subtractive mixing of blue and green. At this time, the voltage applied to the electrode of the first substrate 20 was 5 kV.

In the image displayed by the above-described procedure, even if the application of the electric field is stopped, the blue particles 40 and the green particles 42
And the red particles 44 are held as they are by the intermolecular force between the first substrate 20 and the second substrate 18.

According to the present embodiment, it is possible to selectively charge each of the particles exhibiting blue, green and red selective reflections by irradiating light of different wavelengths, and move the particles by applying an electric field to display an image. As a result, full-color display of an image is possible. That is, it is possible to provide an image display medium and an image display device capable of full-color display having color reproduction by three primary colors similar to a light-emitting or transmissive electronic display.

[0083]

As described above, the present invention selectively generates a hole-electron pair by irradiating light to charge particles of different colors, and generates an electric field by applying a voltage. Since images can be displayed by moving the charged particles to the electrode plate side corresponding to the charges,
There is no need to use a matrix electrode or a pixel electrode to display a multi-color (two or more colors) image, and it has an effect that it can be manufactured with a simple structure and at low cost. Further, according to the present invention, since the resolution of an image is not limited by the electrode resolution as in the case where a matrix electrode or a pixel electrode is used, a high-resolution display can be realized without being limited by the electrode resolution. (Two or more colors) can be repeatedly rewritten.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image display device according to first and second embodiments.

FIG. 2 is a schematic configuration diagram of an image display medium according to the first embodiment.

FIG. 3 is a schematic configuration diagram of an image display medium according to a second embodiment.

FIG. 4 is a schematic configuration diagram of an image display device according to a third embodiment.

FIG. 5 is a schematic configuration diagram of an image display medium according to a third embodiment.

FIG. 6 is a schematic configuration diagram of an image display device according to a fourth embodiment.

FIG. 7 is a schematic configuration diagram of an image display medium according to a fourth embodiment.

FIG. 8 is a diagram showing a state in which the image display medium according to the present invention is exposed by a line exposure device including red, green, and blue light.

FIG. 9 is a view showing a state in which the image display medium according to the present invention is exposed by a planar exposure apparatus having red, green, and blue filters.

FIG. 10 is a view showing a state in which the image display medium according to the present invention is exposed by a red, green, and blue laser exposure device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image display apparatus 12 Image display medium 14 Electric field application means 16a-16e Exposure means (irradiation means) 18 Second substrate 20 First substrate 22 Cyan particles 24 Magenta particles 26 White insulating particles 28 Cyan color Particles 30 White particles 32 Magenta particles 34 Cyan particles 36 Magenta particles 38 Yellow particles 40 Blue particles 42 Green particles 44 Red particles 46 Black particles

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshinori Machida 430 Green Tech Nakanaka, Nakai-cho, Ashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Nobuyuki Nakayama 430 Green Tech Nakai, Nakai-cho, Ashigara-shi, Kanagawa Fuji Fuji Xerox Co., Ltd. (72) Inventor Shota Oba 430 Green Tech Nakai, Nakai-cho, Ashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Motohiko Sakamaki 430 Green Tech Nakai, Nakai-cho Sakai, Ashigara-shi, Kanagawa Fuji Xerox Co., Ltd. 72) Inventor Kiyoshi Shigehiro 430 Green Tech Nakai, Nakai-cho, Ashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Yoshiro Yamaguchi 430 Green Tech Nakai, Nakai-cho, Ashigara-gun, Kanagawa, Japan Fuji Xerox Co., Ltd. F-term (reference) 5C094 AA 05 AA44 AA45 BA76 BA84 CA24 GA01

Claims (8)

[Claims] A first particle including a pair of substrates, a charge transporting material for transporting electrons or holes, and a charge generating material for generating electrons and holes by light irradiation, disposed between the pair of substrates. And an insulating second particle group having a different color from the first particle group. The first particle group is charged by irradiation with light having different wavelengths, and has a different color. An image display medium composed of multiple types of particles. 2. The first particle group includes magenta particles charged by red and blue light, cyan particles charged by green and blue light, and yellow charged by green and red light. 2. The image display medium according to claim 1, comprising color particles. 3. The first group of particles is a particle that reflects green light, is charged by red and blue light, a particle that reflects red light that is charged by blue and green light,
2. The image display medium according to claim 1, comprising particles that reflect blue light and are charged by red and green light. 4. A first particle group including a pair of substrates, a hole transporting material disposed between the pair of substrates, and a charge generating material generating electrons and holes by light irradiation. And a second particle group including an electron transporting material for transporting electrons of a different color from the first particle group and a charge generating material for generating electrons and holes by light irradiation, wherein the first particles are provided. An image display medium, wherein one of the group or the second particle group is charged by irradiation with light of different wavelengths, and includes a plurality of types of particles of different colors. 5. One of the first particle group and the second particle group is a magenta particle charged by red and blue light, a cyan particle charged by green and blue light, 3. The image display medium according to claim 2, comprising yellow particles charged by green and red light. 6. One of the first group of particles or the second group of particles is charged with red and blue light, particles reflecting green light, charged with blue and green light, 3. The image display medium according to claim 2, comprising particles that reflect red light and particles that reflect blue light and are charged by red and green light. 7. An image display medium according to claim 1, wherein an electric field is applied between a pair of substrates, and a plurality of lights having different wavelengths are respectively transmitted from one of the substrates. An image display method for displaying an image by selectively irradiating based on image data. 8. An image display device for displaying an image on the image display medium according to claim 1, wherein an electric field application unit applies an electric field to a pair of substrates of the image display medium. And an irradiating unit for irradiating one of the substrates of the image display medium with light based on image data.