JP2003195361A - Display medium, display device and display body using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a display medium which can solve the problems of the related art and can display more clearly, and a display device and a display body using the same. The present invention relates to a display medium comprising a display cell and a display composition included in the display cell, a substrate 1 having an electrode 2 on one surface and a vertically-aligned liquid crystal alignment film 3 formed on the electrode surface, and one surface. The display cell is formed by arranging a transparent electrode 5 and a transparent substrate 4 having a parallel alignment liquid crystal alignment film 6 formed on the electrode surface so that the alignment film surfaces 3 and 6 face each other. The display composition is composed of a p-type liquid crystalline composition 8, a p-type dichroic dye 9, and electrophoretic particles 7 having a different color tone from the dichroic dye 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display medium capable of reversibly changing its visible state by the action of an electric field, a display device using the same, and a display body.

[0002]

2. Description of the Related Art In an electrophoretic display device, two substrates, at least one of which is transparent, are arranged to face each other with a spacer interposed therebetween to form a closed space. Particles) are filled with a display liquid in which a dispersion medium colored in a color different from that of the particles is filled to form a display panel, and an electric field is applied to the display panel to obtain a display. The substrate surface becomes the display surface.

The display liquid for electrophoretic display filled in the sealed space is a dispersion medium such as xylene or isoparaffin, fine particles (dispersed particles) such as titanium dioxide, a dye for providing a color contrast with the dispersed particles, and an interface. It is composed of a dispersant such as an activator and an additive such as a charge imparting agent. By applying an electric field to the display liquid, the dispersed particles in the display liquid move to the transparent plate side, and the color of the dispersed particles appears on the surface. By applying an electric field in the opposite direction, the dispersed particles move to the back surface side, and the color of the dispersion medium colored with the dye appears on the surface.

Such an electrophoretic display device is a display device that obtains a desired display by controlling the direction of an electric field, and is a low-cost material in which a display liquid is relatively easily available. It is attracting attention as an inexpensive display device because it has advantages such as an extremely wide size, a low power consumption, and a memory property.

Further, a dispersion system (display liquid for electrophoretic display) comprising such dispersed particles and a dispersion medium colored in a color different from that of the dispersed particles is enclosed in microcapsules, and these microcapsules are used as electrodes. An electrophoretic display device having a structure arranged between them has been proposed (Japanese Patent Laid-Open No. 1-86116 (Japanese Patent No. 2551783)), and a simple means has also been proposed as a method for configuring the electrophoretic display device. It was

[0006]

However, in the display liquid of these electrophoretic display devices, a high refractive index inorganic pigment such as titanium dioxide is generally dispersed in a hydrophobic dispersion medium colored by dissolving a dye or the like. Therefore, it is difficult to maintain the stability of the dispersed state, and when the display is repeatedly performed, the contrast is deteriorated due to agglomeration or the like, and the display quality is deteriorated. Further, since these systems generally use a dye solution, adsorption of the dye on the pigment surface and color mixture due to the dye solution entering the gap between the pigment and the pigment are likely to occur, and similarly, the contrast is significantly lowered. It also has a drawback. With respect to these problems, it is considered that the stability of the above-mentioned dispersed state is involved together with the constitution of the dispersion system using the dye solution, and it is required to overcome both of them.

On the other hand, means for improving the dispersion stability have been proposed. For example, a titanate coupling agent as a surface treatment agent for electrophoretic particles was used in a colored dispersion medium colored with a dye. A technique of adding a sorbitan fatty acid ester surfactant to a system has been proposed (JP-A-2-284128). However,
The surfactant used here is insufficient in stabilizing the pigment dispersion in the non-aqueous organic solvent, and is not sufficiently effective under the electrophoretic conditions in which a voltage is applied.

Further, Japanese Patent Application Laid-Open No. 11-119704 proposes that charged particles contain a quaternary ammonium salt compound as a charge control agent. It is described that one of the electrophoretic particles of 1. is treated with the above charge control agent, and a surfactant is further added, but in this case also, sufficient dispersion stability cannot be obtained in the same manner as above. The effect is insufficient.

On the other hand, in addition to improving dispersion stability, various proposals have been made for improving contrast. For example, a dye that is non-adsorptive to the pigment surface is used as a dye used for coloring the dispersion medium (Phl
ips Lab: Conference Record
of 1980 Biennial Disp. Re
s. Conf), lowering the dye concentration in the dispersion medium (XeroxPaloAlto: Proc. SID,
Vol. 18, 3/4, 1977), optimization of dye concentration, pigment concentration, and surfactant (Matsushita: Proc.
SID, Vol. 18, No3 / 4, 197
Improvement by 7) is also proposed. However, in these methods, not only the effect is insufficient, but also the problems such as the decrease in the display density and the response speed due to the dye solution are caused, and the practical solution has not yet been reached.

Further, as described above, there is a method of encapsulating a display liquid for electrophoretic display in microcapsules and using it as display particles, as disclosed in Japanese Patent Laid-Open No. 1-86116.
1783). One of the merits of this method is that uneven display due to uneven distribution of electrophoretic particles can be prevented. However, also in this method, since the display liquid contained therein uses a colored dye solution and a dispersion liquid of pigment particles, the contrast is not sufficient in the same manner as the above phenomenon.

Therefore, as a means for solving the above drawbacks of the system using a colored dispersion medium, a system not using a dye solution has been proposed. For example, a liquid in which at least two kinds of electrophoretic fine particles having different color tones and electrophoretic properties are dispersed in a high-insulating, low-viscosity colorless dispersion medium is provided with a spacer between two opposing electrodes, at least one of which is transparent. An electrophoretic display element enclosed in a cell to be formed has been proposed (JP-A-62-269124). However, in these systems, electrophoretic particles with different color tones have opposite charged charges (positive and negative combination), so a stable dispersion state is not maintained, and aggregation due to electric attraction between particles occurs. By doing so, color mixing occurs, and it is difficult to realize a display having good contrast.

Further, a liquid in which at least two kinds of electrophoretic fine particles having the same electrophoretic property but different in color tone and electrophoretic velocity are dispersed in a colorless insulating medium having a high insulating property and a low viscosity,
An electrophoretic display device has been proposed in which at least one is sealed in a cell formed between two opposing electrodes with a spacer interposed therebetween (Japanese Patent Laid-Open No. 63-50886).
However, even in this case, it is difficult to maintain a stable dispersed state when a collision between particles occurs, and a sufficient function has not been achieved yet. Furthermore, in this case, it is impossible to simultaneously display different color tones on one surface because the difference in the moving speed of the electrophoretic fine particles having different tones that move in the same direction is used. Due to the movement of the particles, the display is slow and it is not practical.

WO98 / is an example in which a microcapsule contains the same dispersion system as the display liquid for electrophoretic display proposed in JP-A-62-269124.
No. 03896, the stability of the dispersion system is not maintained in this case as well, and color mixture due to aggregation due to the electric attraction between the electrophoretic particles occurs in the microcapsules.
This is not a practical means because it causes color mixture in the display.

On the other hand, between the particles, which is a problem in a system using a liquid in which two kinds of electrophoretic fine particles having different color tones and electrophoretic properties (charges) are dispersed as a display liquid for electrophoretic display. As a means for preventing agglomeration, it has been proposed to use a steric repulsion effect due to addition of a charge control agent, surface treatment of particles, etc. (Table 8-5).
10790 publication). However, with the methods described in these, it is difficult to maintain sufficient dispersion stability and completely prevent aggregation between two types of electrophoretic fine particles,
A good contrast has not been achieved yet.

Further, an image display ink composition comprising a concealing white particle composed of a resin and a white pigment, a display colored particle and a solvent has been proposed (JP-A-10-149117). The white particles are obtained by kneading and crushing a white pigment, polymerizing it from a dispersed state, and aggregating it with a resin.Usually, the specific gravity of the solvent in a display liquid for electrophoresis using a dispersion medium colored with a dye is used. White particles used for the purpose of adjusting the difference. Even in this case, since the stability of the dispersed state is not maintained, the function of reducing aggregation between two types of particles in combination with a pigment having a different color tone (coloring pigment for display consisting of magnetic powder alone or a mixture) As described above, the color mixture due to agglomeration is caused, and the contrast is deteriorated.

On the other hand, as an example of the solvent species, it has been proposed to use a linear alkylbenzene as a dispersion medium in a system using a colored dispersion medium colored with a dye (Japanese Patent Laid-Open No. 1-300233 (Patent No. 1)). 261
2474))). However, since these solvents do not have the function of improving the special dispersion stability, it is difficult to improve the dispersion stability and further the contrast by developing this technique.

Further, examples have been proposed in which a mixed solvent of halogen-based tetrachloroethene and alkylbenzene or a mixed solvent of tetrachloroethylene, 5-ethylidene norbornene and aromatic solvent is used as a dispersion medium.
No. 550458 and Japanese Patent Publication No. 9-507881) do not realize sufficient effects like the above linear alkylbenzene.

On the other hand, electrophoretic particles composed of dielectric particles and a dispersion medium composed of a dichroic dye and a nematic liquid crystal,
An electrophoretic display device enclosed in a gap between a transparent substrate and a counter substrate, and 1-1 containing the above electrophoretic particles and a dispersion medium.
An electrophoretic display device including microcapsules having a particle size of 00 μm has been proposed (Japanese Patent Laid-Open No. 2000-662).
47 publication). In the former electrophoretic display device, a vertically oriented alignment film is provided on a transparent substrate that serves as a display surface, and a vertically or horizontally oriented alignment film is provided on a counter substrate that is a back surface so that the liquid crystal on the display surface side is separated from the liquid crystal. The absorption axes of the chromatic dyes are both vertically aligned. When the color tone of the electrophoretic display particles is displayed by this device, that is, when the electrophoretic particles are present on the display surface, the absorption of the dichroic dye existing in the gaps between the electrophoretic particles is eliminated, and the color tone of the electrophoretic particles is reduced. Can be effectively displayed. However, when displaying the color tone of the dichroic dye, that is, when the electrophoretic particles are present on the back surface side, the absorption axis of the dichroic dye becomes more vertically oriented as it is closer to the display surface, and the incident light becomes dichroic dye. Is not absorbed and the desired color tone is not displayed. Therefore, display with high contrast cannot be obtained. Also, when displaying the color tone of electrophoretic display particles with the latter device, the dichroic dye in the microcapsules does not interact with the alignment film as in the former device, so it is randomly aligned and electrophoresed. Color mixing with the color tone of the particles occurs and the contrast deteriorates.

The present invention has been made in view of the above circumstances, and solves the problems of the various conventional techniques described above, and a display medium capable of clearer display, and a display using the same. It is intended to provide a device and a display body.

[0020]

According to a first aspect of the present invention, in a display medium comprising a display cell and a display composition contained in the display cell, the display cell has an electrode on one surface and an electrode on the electrode surface. A substrate having the formed vertical alignment liquid crystal alignment film and a transparent substrate having a transparent electrode on one surface and a parallel alignment liquid crystal alignment film formed on the electrode surface are arranged so as to face each other. And a display medium comprising the p-type liquid crystalline composition, a p-type dichroic dye, and electrophoretic particles having a color tone different from that of the dichroic dye. To do.

[0021] The second aspect of the present invention has a main feature of a display medium in which a protective layer is provided on at least a part of the display medium. This protective layer is for protecting the display surface of the display medium from physical and chemical damage and maintaining visibility.

A third aspect of the present invention has a main feature of a display medium in which a print layer is provided on at least a part of one or both of the display medium and the protective layer. The printing layer used for this display medium is a known offset printing on at least a part of the overcoat layer, depending on the intended use of the display medium,
It may be formed by gravure printing or screen printing.

A fourth aspect of the present invention is characterized by a display medium having a print protection layer provided on the print layer. The print protection layer used for this display medium can be formed by a known method similarly to the print layer.

[0024] A fifth aspect of the present invention is characterized mainly in a display medium provided with an information recording section.

A sixth aspect of the present invention is characterized mainly in a display medium in which the information recording section is a recording section capable of writing and reading information recording by the action of magnetism.

The seventh aspect of the present invention is characterized mainly in the display medium in which the information recording section is an integrated circuit memory or an optical memory.

The eighth aspect of the present invention is characterized mainly in the display medium, in which the information recording section is a transparent recording section capable of reading information recording by the action of light.

A ninth aspect of the present invention is characterized mainly in the display medium in which the information in the information recording section is at least one of information indicating the front and back of the display medium and information indicating the position of the display medium.

A tenth aspect of the present invention comprises the display medium according to any one of the first to eighth aspects, and a writing device capable of displaying visible information on the display medium.
The display medium and the writing device are display devices that are attachable / detachable so as to be brought close to each other at least at the time of writing, and the writing device is equipped with a plurality of signal electrodes and scan electrodes, and an intersection thereof responds to an image signal. Has a switching element that can apply an electric field to the display medium by
A display device configured to display an image on the display medium thereby has the most main feature.

In such a structure, since the two-dimensionally arranged electric field applying means has a switching element, the electric charge applied to a certain portion at the time of selection by the action is a time constant of the material constituting the display medium at the time of non-selection. If the discharge occurs and it is longer than the particle movement time (response time), the selection time can be made shorter than the response time, and as a result, the writing speed becomes faster.

The eleventh aspect of the present invention is mainly characterized by a display device in which a switching element capable of applying an electric field to a display medium according to an image signal is a thin film transistor.

As the switching element, a thin film transistor which can easily manufacture a large area thin film device is preferable.
Since the thin film transistor is a three-terminal element, it has high switching performance, and a clear display can be obtained even in the case where halftone is involved. In addition, in order to further increase the writing speed, the storage capacitor can be provided in parallel with the display medium in an equivalent circuit.

A twelfth aspect of the present invention is characterized by a display body in which the display medium according to any one of the first to ninth aspects and a thin film transistor are integrated.

A thirteenth aspect of the present invention is characterized mainly by a display body in which the display medium according to any one of the first to ninth aspects occupies a part or all of the display medium.

To give an example thereof, the electrophoretic display medium of the present invention constitutes part or all of a small card such as a business card or a credit card so that information can be rewritten. Is produced and can be used as various point cards and membership cards. By increasing the size of such a small card with excellent portability,
A reversible display sheet can also be produced as a substitute display body for a display or recording paper (output paper for a copying machine, printer, etc.) used in a general office or the like. Since such a reversible display sheet can be repeatedly used, it is an excellent display medium from the viewpoint of resource saving and energy saving. Moreover, by incorporating the display medium of the present invention into various articles such as home electric appliances, it becomes possible to provide information instead of the conventional liquid crystal monitor. In this case, excellent display with a wide viewing angle and a high contrast can be realized.

A fourteenth aspect of the present invention is a reversible display card,
The main feature is a reversible display sheet, a reversible display, or a display that is a reversible display type signboard. In other words, this display body can be used for various advertisements, signboards, and the like, and in this case, the entire surface can be composed of an electrophoretic display medium, but it is effective by incorporating it in a part of a poster or the like. It is also possible to realize various displays.

A fifteenth aspect of the present invention is a reversible display card,
The main feature is that the display body, which is a reversible display sheet, a reversible display, or a reversible display type signboard, has flexibility. In other words, since it is possible to give flexibility to the display body, it is not restricted by the shape in various applications such as the above-mentioned card, sheet, display, signboard, and advertisement, and can be used in a very wide range of applications. It becomes possible to respond.

[0038]

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

Here, prior to the description of the specific embodiments, the outline of the present invention will be described. The present invention provides a display medium comprising a display cell and a display composition contained in the display cell, The display cell has a substrate having an electrode on one surface and a vertical alignment liquid crystal alignment film formed on the electrode surface, and a transparent substrate having a transparent electrode on one surface and a parallel alignment liquid crystal alignment film formed on the electrode surface. The display composition is formed by arranging the substrate and the orientation film surfaces of the substrates so as to face each other, and the display composition has a p-type liquid crystalline composition, a p-type dichroic dye, and a color tone different from that of the dichroic dye. The vertical alignment liquid crystal alignment film and the parallel alignment liquid crystal alignment film provided on the electrode surface of the substrate control the alignment of liquid crystal molecules constituting the liquid crystal composition. Alignment film Points.

The former is an alignment film for aligning the long axis direction of liquid crystal molecules perpendicularly to the substrate, and an alignment agent such as lecithin, dimethylchlorosilane, octadecylchlorosilane, stearic acid or hexadecyltrimethylammonium bromide is applied by solution coating. Physical adsorption, a method in which an orientation agent such as a monobasic chromium carboxylic acid complex or an organic silane is applied and chemically adsorbed, plasma polymerization of an orientation agent such as hexamethyldisiloxane, perfluorodimethylcyclohexane or tetrafluoroethylene. A method of sputtering an aligning agent such as polytetrafluoroethylene, a method of physically injecting an aligning agent such as lecithin or octadecylmalonic acid by liquid crystal injection, or a method of deforming and orienting the substrate surface. Alignment film .

The latter is an alignment film for aligning the long axis direction of liquid crystal molecules parallel to the substrate, and a method of applying an aligning agent such as carbon, polyoxyethylene, polyvinyl alcohol, or polyimide to cause physical adsorption. A method in which an aligning agent such as a basic chromic acid carboxylic acid complex or an organic silane is applied by solution and chemically adsorbed, a method in which an aligning agent such as acetylene is plasma polymerized, an aligning agent such as a dibasic fatty acid or crown ether is injected by liquid crystal dissolution injection. And an alignment film formed by a method of physically adsorbing, or a method of deforming and orienting the surface of the substrate.

The p-type liquid crystal composition constituting the display composition is
It is composed of a liquid crystal compound showing a nematic phase, a smectic phase, or a chiral nematic phase having a positive dielectric anisotropy, or a mixture thereof, and is aligned so that the long axis direction of the liquid crystal molecules is parallel to the electric field when a voltage is applied.

The p-type dichroic dye is a dye having a light absorption transition moment in the long axis direction of the molecule. The p-type dichroic dye is arranged in parallel with the liquid crystal molecules, and when the liquid crystal composition is arranged in parallel with the substrate, the color tone of the p-type dichroic dye is visually recognized. Conversely, when it is arranged vertically with respect to the substrate, a transparent color tone is displayed. To be done.

The electrophoretic particles having a color tone different from that of the dichroic dye move to one of the electrodes according to the electrophoretic polarity by applying an electric field. When moving to the transparent substrate side which is the display surface, the color tone of the electrophoretic display particles is displayed.

The electrophoretic particles are lead white, zinc white, lipoton, titanium dioxide, zinc sulfide, antimony oxide, calcium carbonate, kaolin, mica, barium sulfate, gloss white, alumina white, talc, silica, calcium silicate, or the like. One or more inorganic pigments selected from
Alternatively, there are composite particles in which those inorganic pigments are attached to the surface of the polymer particles or the hollow polymer particles or introduced therein.

According to the display medium composed of such a display cell and the display composition, as shown in FIG. 1A, a voltage is applied via the electrode 2 on the substrate 1 and the transparent electrode 5 on the transparent substrate 4. When applied, the electrophoretic particles 7 move to the transparent substrate 4 side depending on the polarity of the electric field. At the same time, the p-type liquid crystal composition 8 and the p-type dichroic dye 9 are not affected by the parallel alignment liquid crystal alignment film 6 due to physical obstacles of the electrophoretic display particles that have moved,
Due to the influence of the electric field and the vertical alignment liquid crystal alignment film 3, alignment is performed in the direction perpendicular to the substrate, and the color tone of the electrophoretic particles without color mixing due to the dichroic dye 9 is displayed. After the voltage application is stopped, the electrophoretic particles are held by the cohesive force between the particles and the adsorption force with the alignment film to maintain an effective color tone state, while the p-type liquid crystal composition 8 and the p-type dichroic dye are maintained. 9 is a vertical alignment liquid crystal alignment film 3
It will continue to be affected by and will remain transparent. Therefore,
The color tone of the electrophoretic particles 7 can be effectively displayed without color mixture.

Further, as shown in FIG. 1B, when a voltage having a polarity opposite to the above is applied, the electrophoretic particles move to the substrate 1 side. At the same time, the p-type liquid crystal composition 8 and the p-type dichroic dye 9 are aligned in the direction perpendicular to the substrate under the influence of the electric field,
The color tone of the electrophoretic particles 7 is displayed. However, when the voltage application is stopped, the liquid crystal composition 8 and the dichroic dye 9 are horizontally aligned under the influence of the parallel alignment liquid crystal alignment film 6, and the color tone of the dichroic dye 9 is displayed.

Next, a preferred embodiment of the display medium of the present invention will be described with reference to FIG. The substrate 1 is a transparent or colored substrate made of a glass plate or a plastic film. The transparent substrate 4 is a transparent substrate made of a glass plate or a plastic film. The thickness of the substrates 1 and 4 is about 10 μm to 1 mm, preferably 25 to 200 μm. The electrode 2 may be transparent or colored and is made of a conductive thin film such as metal, ITO, SnO ₂ , ZnO: Al, etc., and is used for spattering method, vacuum deposition method, CVD method,
It is formed by a coating method or the like. The electrode 5 is ITO, SnO
₂ , a transparent electrode made of a transparent material such as ZnO: Al. Electrodes 2 and 5 are patterned or unpatterned electrodes in a matrix, and at least one of them is an unpatterned electrode. The unpatterned electrode can be used as a common electrode. The vertical alignment liquid crystal alignment film 3 and the parallel alignment liquid crystal alignment film 6 are formed by a physical adsorption method, a chemical adsorption method, a plasma polymerization method,
Alternatively, it is preferably provided by a modified alignment treatment method or the like and subjected to rubbing treatment in order to improve the effect of the alignment film. The display composition 10 comprises a liquid crystal composition, a dichroic dye and electrophoretic display particles.

The protective layer 11 comprises a protective layer material and, if necessary, a medium for dissolving, dispersing, suspending or emulsifying the material, a protective layer material composition containing a curing agent, a catalyst and / or a cocatalyst. Is formed by a coating method such as wire bar coating, roll coating, blade coating, dip coating, spray coating, spin coating or gravure coating, or a vapor phase method such as sputtering and chemical vapor deposition.

The thickness of the protective layer 11 is preferably as thin as possible within a range having a function of protecting the substrate 4, and is preferably about 0.1 to 100 μm, more preferably 0.3 to 30 μm.
Is. The protective layer material is polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinyl alcohol, polyethylene oxide, polypropylene oxide, ethylene-vinyl alcohol copolymer, polyacetal, Acrylic resin, methyl cellulose, ethyl cellulose, phenol resin, fluorine resin, silicone resin, diene resin, polystyrene thermoplastic elastomer, polyolefin thermoplastic elastomer, polyurethane thermoplastic elastomer, polyester thermoplastic elastomer, polyphenylene ether, polyphenylene sulfide, poly Ether sulfone, polyether ketone, polyarylate, aramid,
Polyimide, poly-p-phenylene, poly-p-xylene, poly-p-phenylene vinylene, polyhydantoin, polyparabanic acid, polybenzimidazole, polybenzothiazole, polybenzoxadiazole, polyquinoxaline, thermosetting resin or active It is composed of an energy ray curable resin or a mixture thereof.

The printing layer 12 can be provided on at least a part of the protective layer except the display portion by a known method. The print protection layer 13 is made of the same material as the protection layer 11, and can be provided on the print layer and on the protection layer by the same method as the protection layer or the print layer.

Next, another embodiment of the present invention will be described with reference to FIG. The substrate 1, the transparent substrate 4, the electrode 2, the transparent electrode 5, the vertical alignment liquid crystal alignment film 3, the parallel alignment liquid crystal alignment film 6, the display composition 8, and the protective layer 13 are the same as those in FIG. Figure 3
As shown in (a), the magnetic recording portion 2 is provided on the non-display surface 26.
3 and integrated circuit memory 24 on at least part of substrate 1
The magnetic recording unit 23 and the integrated circuit memory 24 provided on the top
And the second protective layer 25 is provided on the substrate. Second protective layer 25
Is formed from the same material as the material forming the protective layer or the print protective layer. As shown in FIG. 3B, the transparent recording portions 22 can be provided in a grid pattern. The intersection of the row _{x n} column _{y m} formed _(x n, _{y m)} reads /
It can be uniquely used as write information and used as digital information. That is, in the case of such a display medium, the display of the display composition 10 is visible through the transparent substrate 4, the transparent common electrode 5, and the transparent recording portion 22, and at the same time, digital information corresponding to the display or independent digital information is displayed. Can be written and read.

[0053]

EXAMPLES The present invention will be described in more detail based on the following examples, but these are only one aspect of the present invention, and the technical scope of the present invention is not limited thereto.

Example 1 [Preparation of display medium] Two transparent substrates each having a transparent electrode made of ITO provided on one surface of a transparent glass plate having a thickness of 3 mm by a sputtering method were prepared and oriented on one electrode surface. Agent JALS-682-R6 (manufactured by JSR, concentration 3.0
%) Was applied and dried at 80 ° C. After firing at 120 ° C. for 2 hours, rubbing treatment was performed to provide a vertical alignment liquid crystal alignment film. Alignment agent AL1254 (J
SR Co., Ltd., concentration 2.5%) was applied, dried at 80 ° C., baked at 120 ° C. for 2 hours, and rubbed to provide a parallel alignment liquid crystal alignment film. Place the mutual electrode surfaces facing each other,
A display cell was obtained by forming an internal space having a distance between the electrode surfaces of about 18 μm with a nylon spacer.

100.0 g of nematic liquid crystal composition MX
1543 (Merck) 0.4g dichroic dye KRD
-901 (Showa Kako Co., Ltd., maximum absorption wavelength 552 nm, 5
72 nm) and 2.5 g of oleic acid are dissolved, 12.0 g of titanium oxide CR50-2 (manufactured by Ishihara Sangyo Co., Ltd.) is added to the resulting solution, and ultrasonically dispersed for 15 minutes to give a display composition. Was prepared. Injecting this display composition into a display cell,
After degassing under reduced pressure, the gap between the substrates was sealed to produce a display medium.

Example 2 [Preparation of display medium] 100.0 g of nematic liquid crystal composition MX1545 (manufactured by Merck) was added with 0.5 g of dichroic dye M-403 (manufactured by Mitsui Toatsu, maximum absorption wavelength 678 nm).
And 2.5 g of oleic acid were dissolved, and 1 was added to the resulting solution.
2.0 g of titanium oxide CR50-2 (manufactured by Ishihara Sangyo Co., Ltd.) was added and ultrasonically dispersed for 15 minutes to prepare a display composition. This display composition was injected into a display cell similar to that in Example 1, degassed under reduced pressure, and then the gap between the substrates was sealed to produce a display medium.

Example 3 [Preparation of Display Medium] 100.0 g of nematic liquid crystal composition ADK-9499 (manufactured by Asahi Denka Kogyo Co., Ltd.) and 0.5 g of dichroic dye G-232 (manufactured by Nippon Senshoku Co., Ltd., maximum) (Absorption wavelength 450 nm) and 2.5 g of oleic acid are dissolved, 12.0 g of titanium oxide CR50-2 (manufactured by Ishihara Sangyo Co., Ltd.) is added to the resulting solution, and ultrasonic dispersion is carried out for 15 minutes to display. A composition was prepared. This display composition was injected into a display cell similar to that in Example 1, degassed under reduced pressure, and then the gap between the substrates was sealed to produce a display medium.

Comparative Example 1 Two transparent substrates each having a transparent electrode made of ITO provided on one surface of a transparent glass plate having a thickness of 3 mm by a sputtering method were prepared, and an aligning agent AL1254 (JSR) was provided on both electrode surfaces.
(Manufactured by the company, concentration 2.5%), and dried at 80 ℃,
It was baked at 120 ° C. for 2 hours and rubbed to form a parallel alignment liquid crystal alignment film. The respective electrode surfaces were opposed to each other, and an internal space having a distance between the electrode surfaces of about 18 μm was formed by a nylon spacer to obtain a display cell. A display composition similar to that in Example 1 was injected into this display cell to prepare a display medium in the same manner as in Example 1.

Comparative Example 2 A display medium was prepared in the same manner as in Comparative Example 1 except that the display composition of Example 2 was used.

Comparative Example 3 A display medium was prepared in the same manner as in Comparative Example 1 except that the display composition of Example 3 was used.

Example 4 A voltage of +500 V or -500 V was applied to the display mediums produced in Examples 1 to 3 and Comparative Examples 1 to 3 through the electrodes of the medium for 10 seconds, then the electric field was removed, and A display dependent on a chromatic dye (display of a dichroic dye) and a display dependent on electrophoretic particles (display of electrophoretic particles) were performed. Place the display cell on the standard reflection plate, and make a photoal by Otsuka Electronics Co., Ltd.
The reflectance of each cell was measured in the wavelength range of 380 to 800 nm by using the MCPD-1000 by 45-degree irradiation-vertical light reception. Regarding the reflectance at the wavelength corresponding to the maximum absorption wavelength wave of the dichroic dye in each cell, the ratio of the electrophoretic particle display to the dichroic dye display (contrast ratio) was obtained. As a result, Examples 1 to 3 exhibited higher contrast ratios than Comparative Examples 1 to 3, respectively, and it was revealed that a display medium with high visibility can be obtained by using the display medium of the present invention.

[0062]

According to the above-described display medium of the present invention, and the display device and the display body using the same, it is possible to solve the problems of the prior art, and to provide a clearer display, and It is possible to provide an excellent effect that it is possible to provide a display device and a display body using the.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the outline of the present invention,
(A) is a conceptual diagram showing a state in which a voltage is applied between electrodes,
(B) is a conceptual diagram showing a state in which a voltage having a reverse polarity to (a) is applied.

FIG. 2 is a sectional view showing an example of an embodiment for carrying out the present invention.

FIG. 3 shows another embodiment of the present invention, (a) is a sectional view,
(B) is a top perspective view.

[Explanation of symbols]

1 substrate 2 electrodes 3 Vertical alignment liquid crystal alignment film 4 transparent substrate 5 electrodes 6 Parallel alignment liquid crystal alignment film 7 Electrophoretic particles 8 Liquid crystal composition 9 Dichroic dye 10 Display composition 11 Protective layer 12 printing layers 13 Print protection layer 14 Display surface 21 Transparent recording section 22 Protective layer 23 Magnetic recording unit 24 Integrated circuit memory 25 Second protective layer 26 Non-display surface

Claims (15)

[Claims] 1. A display medium comprising a display cell and a display composition contained in the display cell, wherein the display cell has a substrate having an electrode on one surface and a vertical alignment liquid crystal alignment film formed on the electrode surface. , A transparent substrate having a transparent electrode on one surface and a parallel alignment liquid crystal alignment film formed on the electrode surface, is formed by arranging them so that both alignment film surfaces face each other, and the display composition, A display medium comprising a p-type liquid crystalline composition, a p-type dichroic dye, and electrophoretic particles having a different color tone from the dichroic dye. 2. The display medium according to claim 1, wherein a protective layer is provided on at least a part of the display medium. 3. The display medium according to claim 2, wherein a print layer is provided on at least a part of one or both of the display medium and the protective layer. 4. The display medium according to claim 3, wherein a print protection layer is provided on the print layer. 5. The display medium according to claim 1, further comprising an information recording section. 6. The display medium according to claim 5, wherein the information recording unit is a recording unit capable of writing and reading information recording by the action of magnetism. 7. The display medium according to claim 5, wherein the information recording section is an integrated circuit memory or an optical memory. 8. The display medium according to claim 5, wherein the information recording section is a transparent recording section from which information recording can be read by the action of light. 9. The information according to claim 5, wherein the information in the information recording section is at least one of information indicating front and back of the display medium and information indicating a position of the display medium. Display medium. 10. The display medium according to claim 1, and a writing device capable of displaying visible information on the display medium, wherein the display medium and the writing device at least write data. In some cases, the display device is detachable so as to be brought close to each other, and the writing device is equipped with a plurality of signal electrodes and scan electrodes, and an electric field is applied to a display medium at an intersection thereof according to an image signal. A display device having a switching element capable of displaying an image on the display medium. 11. The display device according to claim 10, wherein the switching element capable of applying an electric field to the display medium according to an image signal is a thin film transistor. 12. A display body, wherein the display medium according to claim 1 and a thin film transistor are integrated. 13. A display body, wherein the display medium according to any one of claims 1 to 9 occupies a part or all of the display medium. 14. The display according to claim 13, which is a reversible display card, a reversible display sheet, a reversible display, or a reversible display type signboard. 15. The display according to claim 14, wherein the reversible display card, the reversible display sheet, the reversible display, or the reversible display type signboard has flexibility.