JP2001125148A - Display device and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain uniform dispersion of electrified particles and to decrease uneven distribution of the electrified particles for long-term use in a display device which displays by applying a voltage on a dispersion system having electrified particles dispersed in an insulating liquid to move the electrified particles. SOLUTION: A first electrode 5 and a conductive film 9 are formed on the surface of a light-transmitting tube 4 in which partition walls 10 are regularly formed in the longitudinal direction on the inner wall by partial shrinking by heat, and a dispersion system 3 having electrified particles 2 dispersed in an insulating liquid 1 is sealed in the tube 4. A plurality of these tubes are arranged on a first substrate 7 with the first electrode 5 in contact with the first substrate 7, and a second substrate 8 having a second electrode 6 is disposed and fixed on the tubes 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display system comprising a pair of electrodes and a dispersion system in which charged particles are dispersed in an insulating liquid. The present invention relates to a display device and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, with the development of information equipment, needs for low power consumption and thin display devices have increased, and research and development of display devices meeting these needs have been actively conducted. Among them, a liquid crystal display device can change the optical characteristics of liquid crystal by electrically controlling the arrangement of liquid crystal molecules,
Active developments have been made and commercialized as display devices that can meet the above needs. However, this liquid crystal display device has not yet sufficiently solved the burden on vision caused by the difficulty in seeing characters on the screen due to the angle of viewing the screen and reflected light, flickering of the light source, low luminance, and the like. For this reason, research on a display device with a small burden on vision has been actively studied.

[0003] In view of such low power consumption and reduction of visual burden, a reflection type display device is expected. As one of them, an electrophoretic display device is known. In the electrophoretic display device, as shown in FIG. 7, a dispersion system 73 including charged particles 72 and an insulating liquid 71 is sandwiched between substrates 77 and 78 via an outer frame 79, and a set of electrodes 75 and 76 is provided. Is arranged. In this configuration, when a voltage is applied between the electrodes 75 and 76, the charged particles 72 can be attracted to the electrode having a polarity opposite to the charge of the particles themselves. Here, by coloring the insulating liquid 71 and the charged particles 72 in different colors from each other, display can be performed according to the direction of the electric field applied to the electrodes 75 and 76.

That is, when the charged particles move to the side of the electrode 75 located on the side opposite to the observer when the substrate 78 side is set to the observer side, the observer gives the observer a charge of the charged particles 72. The color is not recognized, and the color of the insulating liquid 71 is observed. on the other hand,
In the case of (b) in which the charged particles 72 are moved to the electrode 76 side by reversing the electric field applied between the electrodes 75 and 76,
The observer observes the charged particles 72 attached to the electrode 76, and can perform a binary display by the colors of the charged particles 72 and the insulating liquid 71.

[0005] Further, it is possible to perform color display by coloring the charged particles or the insulating liquid into a plurality of colors.

In such an electrophoretic display device,
When used repeatedly for a long time, the concentration distribution of the charged particles 72 may be biased, resulting in display unevenness. Therefore, as a method for preventing such a bias in the concentration distribution, for example, JP-A-59-34518 or JP-A-2-28.
Japanese Patent No. 4124 and the like disclose a method in which partitions are formed at regular intervals in an enclosing portion and divided into small sections.

[0007] For example, Japanese Patent Application Laid-Open No. 1-114828 proposes a method of using a porous spacer made of a member swelling with a dispersion medium, injecting a dispersion system, and dividing the dispersion system into discontinuous small sections. I have.

[0008]

However, in such a conventional electrophoretic display device, when a partition wall of an enclosing portion is formed for the purpose of preventing display unevenness due to bias of the concentration distribution of charged particles as described above. In this method, the charged particles must be evenly distributed to each small section, and uniform distribution is difficult. In addition, there is a problem that a lot of time and cost are required for a series of manufacturing processes that require formation of partition walls on a substrate, uniform distribution of charged particles and insulating liquid, and sealing.

Further, in the case of performing color display, since charged particles or insulating liquids of a plurality of colors are used, even if divided into small sections by partition walls, color mixing easily occurs in adjacent sections at the time of manufacturing, and a desired color is obtained. It is difficult to fill only the charged particles or the insulating liquid. Therefore, there is a problem in that color display is more difficult to manufacture.

An object of the present invention is to provide a more inexpensive display device by reducing the display cost while reducing the display unevenness.

[0011]

According to the present invention, there is provided a display device comprising a first substrate and a second substrate opposed to each other and charged particles dispersed in an insulating liquid sandwiched between the substrates. And a first electrode and a second electrode for applying a voltage to the dispersion.
A display device having at least an electrode, and performing display by moving the charged particles in the direction of the first electrode or the second electrode by a voltage applied between the first electrode and the second electrode, The dispersion system is filled in a light-transmissive tube made of an insulating material arranged in parallel between the substrates, and the tube has a partition wall protruding on an inner wall surface in a direction perpendicular to the longitudinal direction of the tube. A first linear electrode having a regular shape in the longitudinal direction of the tube and parallel to the longitudinal direction of the tube is formed between each tube and the first substrate for each tube, and the second electrode is connected to the tube. It is characterized by being formed between the first substrate and the second substrate.

In the present invention, either the first electrode and the first substrate or the second electrode and the second substrate are light-transmitting, and a conductive film is provided between the second electrode and the tube. Being formed, the charged particles are moved vertically between the first electrode and the second electrode within a range defined by the partition, and the partition is formed on a side surface of the light-transmitting tube perpendicular to the substrate. Is formed, the light-transmitting tube is made of resin, the light-transmitting tube has flexibility, the insulating liquid and the charged particles have different colors, especially the insulating liquid or the charged particles. One of the tubes is colored yellow, magenta, or cyan for each tube. Furthermore, the tubes are arranged so that yellow, magenta, and cyan are regularly arranged. The first electrode is formed in a stripe shape orthogonal to the tube. If it forms a matrix with the second electrode, it is intended to include a preferred embodiment of.

The method of manufacturing a display device according to the present invention is the method of manufacturing a display device according to the present invention, wherein the display device is provided outside the light-transmissive tube made of an insulating material and has a line shape parallel to the longitudinal direction of the tube. Forming a first electrode, and forming partition walls protruding in a direction perpendicular to the longitudinal direction of the tube on the inner wall surface of the light-transmitting tube made of an insulating material regularly in the longitudinal direction of the tube. A step of enclosing a dispersion system formed by dispersing charged particles in an insulating liquid in a light-transmissive tube made of an insulating material; and a tube enclosing the dispersion system by forming the first electrode and the partition wall. Is disposed and fixed between the second substrate on which the second electrode is formed and the first substrate such that the first electrode is in contact with the first substrate and the second electrode is in contact with the tube; At least.

In the manufacturing method of the present invention, the insulating liquid and the charged particles are simultaneously filled in a light-transmitting tube.
Alternatively, the insulating liquid and the charged particles are individually filled in a light-transmitting tube, the cross-section of the light-transmitting tube is rectangular, or the light-transmitting tube has flexibility, Deforming the cross-sectional shape of the tubes when they are fixed between the first substrate and the second substrate so that the tubes are in close contact with each other; the light-transmitting tube is made of a heat-shrinkable material; Press-forming the light-transmitting tube with a jig to form a partition, forming a convex portion on the outside of the light-transmitting tube, and placing the tube between the first substrate and the second substrate. When fixing to the, to form a partition in the tube by pushing the convex portion into the tube,
Is included as a preferred embodiment.

In the display device of the present invention, a light-transmissive tube enclosing the dispersion system is arranged between the substrates, and furthermore, a partition is provided in the tube. The occurrence of unevenness is greatly reduced. Further, in the manufacturing method of the present invention, since the first electrode is formed on the light-transmitting tube and disposed between the substrates, there is no need to align the first electrode with the light-transmitting tube. In addition, charged particles or insulating liquids of different colors can be easily and individually sealed without mixing colors.

[0016]

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

FIG. 1 is a perspective view schematically showing a configuration of a display device according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a part thereof. 1 and 2, 1 is an insulating liquid, 2 is a charged particle, 3 is a dispersion system, 4 is a light-transmitting tube,
5 is the first electrode, 6 is the second electrode, 7 is the first substrate, 8 is the second electrode
The substrate, 9 is a conductive film, and 10 is a partition.

As shown in FIGS. 1 and 2, in the display device of the present invention, a dispersion system 3 in which charged particles 2 are dispersed in an insulating liquid 1 is sealed in a light-transmitting tube 4. It is sandwiched between the first substrate 7 and the second substrate 8. In addition, in FIG. 1, in order to show the internal structure of the tube 4, for convenience, the end of the tube 4 is shown in an open form. In addition, the light transmitting tube 4
A first electrode 5 is formed in a line shape in parallel with the longitudinal direction of the tube, and a second electrode 6 is formed on the second substrate 5. In the present invention, a matrix can be formed by forming the second electrodes 6 in a stripe shape and arranging the second electrodes 6 orthogonally to the first electrodes 5.

In the present invention, the first electrode 5 is disposed in contact with the first substrate 7. In addition, by forming a conductive film 9 in advance on a surface of the tube 4 in contact with the second electrode 6, the charged particles are electrically connected between the conductive film 9 and the second electrode 6. 2 can be performed more reliably.

In the present invention, the first electrode 5 and the second electrode 6 are arranged to face each other, and the charged particles 2 are vertically moved between the electrodes, that is, between the first electrode surface and the second electrode surface. The display is performed by moving between the images. For example, FIG.
As shown in (a), when the charged particles 2 in the insulating liquid 1 are collected on the first electrode 5 by applying a voltage between the first electrode 5 and the second electrode 6, the observer (on the side of the second substrate 8) ), The color of the insulating liquid 1 is observed (displayed). On the other hand, as shown in FIG. 2B, the polarity of the voltage is changed to charge the charged particles 2 to the second electrode 6.
When collected on the side, the color of the charged particles 2 is observed. With this configuration, for example, the charged particles 2 are blackened,
If the insulating liquid 1 is white, binary display of black and white is possible.

In the display device of the present invention, partition walls 10 projecting in a direction perpendicular to the longitudinal direction of the tube 4 are regularly formed on the inner wall surface of the tube 4 in the longitudinal direction of the tube 4. With the partition walls, the moving range of the charged particles 2 that repeatedly move in the dispersion system 3 can be limited to a range delimited by two adjacent partition walls 10. As a result, it is possible to reduce the bias of the charged particles 2 in the tube 4 due to long-time use, and it is possible to greatly suppress the occurrence of display unevenness.

In the embodiment shown in FIGS. 1 and 2, an example is shown in which the partition wall 10 is formed over the entire inner wall surface of the tube 4, but if the movement of the charged particles 2 can be suppressed. Alternatively, the partition 10 may be provided only on the side surface of the tube 4 perpendicular to the substrate. The moving range of the charged particles 2 may be completely sealed by the partition wall 10.

A step of enclosing the dispersion system 3 in the tube 4;
The order of the step of forming the first electrode outside the tube 4, the step of forming the conductive film 9 outside the tube 4, and the step of forming the partition wall 10 on the inner wall surface of the tube 4 are not particularly limited, and may vary depending on operating conditions. It may be appropriately moved back and forth.

As a specific method for forming the partition 10, a method in which the light-transmissive tube 4 is formed from a heat-shrinkable material and then heat-shrinked by a heat treatment is used. A method of performing press molding, or forming the tube 4 from a flexible material and forming a convex portion corresponding to the partition on the outside thereof, for example, when the tube 4 is finally fixed between the substrates, The method of forming the partition 10 by pushing the part into the tube 4 is preferably applied.

The pitch and size of the partition 10 are appropriately determined according to the size of the display pixel.

In the display device shown in FIGS. 1 and 2, when the second electrode 6 side is set to the observer (display) side, the second substrate 8 and the second electrode 6 are made light-transmissive. Conversely, when the first electrode 5 side is the observer side, the first electrode 5 and the first substrate 7 are made to be light-transmissive.

In the display device of the present invention, color display can be performed by using the insulating liquid 1 or the charged particles 2 of a plurality of colors. For example, insulating liquid 1
Alternatively, the charged particles 2 may be yellow (Y), magenta (M),
Colored in any of cyan (C), three colors as one set,
If the light transmissive tube 3 is arranged so that the three colors are regularly arranged, color display can be performed by a combination of these. For example, when the second electrode 6 is the observer side and the insulating liquid 1 is colored in the above three colors and the charged particles are white, when displaying white, all the charged particles 2 are the second electrode 6.
In the case where black is displayed on the first electrode 5 side, all the charged particles may be collected on the first electrode 5 side. The opposite is true when the charged particles 2 are colored in the above three colors and the insulating liquid 1 is white.

Next, the manufacturing method of the present invention will be described as an embodiment of the manufacturing method of the display device shown in FIGS. 3 to 5 are drawings related to the manufacturing process. In the present embodiment, an example in which a partition 10 is formed on the inner wall surface of the light-transmitting tube 4 in advance by the above-described method or the like will be described as an example.

First, the first electrode 5 is placed on the surface of the light-transmitting tube 4.
Is formed, and a dispersion system 3 composed of the charged particles 2 and the insulating liquid 1 is sealed in a tube 4. Either the formation of the first electrode 5 or the encapsulation of the dispersion system 3 may be performed first. Here, the case where the electrode is formed first will be described.

The material of the light-transmitting tube 4 is not particularly limited as long as it has an insulating property and a light-transmitting property. However, acrylic resin, polystyrene, polyethylene terephthalate (PET), and polyethylene having high visible light transmittance are used. A resin such as ether sulfone (PES), gelatin, or an inorganic material such as glass or quartz is used. Among them, a resin is preferably used. The light-transmitting tube 4 according to the present invention is
The shape when sandwiched between the substrates in advance, for example, the cross section may be formed in a rectangular shape to encapsulate the dispersion system, but after being formed of a flexible material and placed between the substrates, It may be deformed.

The diameter of the tube 4 according to the present invention is appropriately set according to the size of the display pixel. The thickness of the tube 4 depends on the material, but is preferably 5 μm to 30 μm.

In this embodiment, the pipe 4 is made of a flexible material.
An example in which is formed.

The material for forming the first electrode 5 formed on the surface of the tube 4 is Al, Au, Pt, A
g, Ni, Ti, Cr, or the like can be used. When the first electrode 5 is made transparent, a metal oxide transparent material such as ITO (indium tin oxide), ZnO, or SnO ₂ is used. it can. In addition, as a method of forming an electrode film on the surface of the tube 4, a vacuum deposition method, a sputtering method, an ion plating method, or the like can be used.

As shown in FIG. 3 (a), the first electrode 5 is formed in a line with a constant width in parallel with the longitudinal direction of the tube 4, and the width of the electrode at this time depends on the size of the pixel or the like. It is appropriately selected according to the thickness of the tube 4 and the like. FIG. 3B is a cross-sectional view of FIG.

Further, as shown in FIG.
Preferably, a conductive film 9 is formed in advance on the opposite side of the electrode 5, that is, on a portion where the tube 4 contacts the second electrode 6. The material and forming method of the conductive film 9 are the same as those of the first electrode 5. FIG. 3D is a cross-sectional view of FIG.

Next, the insulating liquid 1 and the charged particles 2 are filled in the tube 4.

The insulating liquid 1 used in the present invention includes oils such as silicone oil and olive oil, aromatic hydrocarbons such as toluene and xylene, and aliphatic or halogenated such as paraffinic hydrocarbons (normal paraffin and isoparaffin). A liquid having a low viscosity, such as a hydrocarbon, a high-purity petroleum, or the like, on which charged particles can be favorably and stably charged, is preferably used. Among them, silicone oil and isoparaffin are preferably used. As the isoparaffin, "Shellsol 70, 7" manufactured by Shell Japan KK
1,72 ", Exxon Chemical Co., Ltd." Isopar G,
H, L, M "," IP Solvent 16 "manufactured by Idemitsu Oil Co., Ltd.
20, 2028, 2835 "and the like. In order to match the specific gravity of the insulating liquid 1 and the specific gravity of the charged particles 2, an insulating liquid having a large specific gravity is mixed as needed.
In the case where color display is performed by coloring the insulating liquid 1, a dye or the like is used as a coloring agent after being dissolved or dispersed in the liquid.

The charged particles 2 used in the present invention include:
A material that can be charged in the insulating liquid 1 is used, and its color may be the color of the material itself, a color to which a coloring agent is appropriately added, or a material obtained by laminating and mixing another material on the particle surface. Further, the charged particles 2 may be composed of one kind or two or more kinds of materials. Specifically, for example, a mixture of a resin such as titanium oxide (white), aluminum oxide (white), polyethylene, polystyrene, and acrylic resin mixed with a coloring agent is preferably used. As the coloring agent, widely used, including carbon (black), and known dyes and pigments such as phthalocyanine blue, induslen blue, peacock blue, permanent red, lake red, rhodamine lake, hansa yellow, permanent yellow, and benzine yellow. can do. In addition, a charge control agent is provided as needed.

The size of the charged particles 2 is preferably from 0.1 μm to 50 μm, more preferably from 0.1 μm to 10 μm.

In the dispersion system 3 according to the present invention, the mixing ratio of the charged particles 2 is preferably 0.2% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass.

In the present invention, as a method for filling the charged particles 2 and the insulating liquid 1 into the tube 4, for example, as shown in FIG.
As shown in (a), the insulating liquid 1 and the charged particles 2 are placed in an appropriate container 41, and the tube 4 is stirred while the insulating liquid 1 is stirred.
Is charged into the liquid, and charged with the charged particles 2 and the insulating liquid 1 at the same time while sucking from the other end. Alternatively, as shown in FIG. 4B, after the charged particles 2 are attached to the inner wall of the tube 4 in advance, the insulating liquid 1 is put into the tube 4,
The charged particles 2 and the insulating liquid 1 can be individually filled. By applying a voltage to the first electrode 5 at the time of filling, the charged particles 2 can be uniformly attached to the first electrode 5. In this way, the dispersion system 3 is
After filling the inside, both ends of the tube 4 are closed and sealed by heating or the like.

Next, the tube 4 enclosing the dispersion system 3 is arranged between the substrates according to the process shown in FIG. That is, first,
As shown in FIG. 5A, a second electrode 6 is formed on the second substrate 8 by patterning. As a material of the second substrate 8, a material having high heat resistance, for example, polyethylene terephthalate (P
ET), a resin film such as polyethersulfone (PES), or an inorganic material such as glass or quartz. When the display device is observed from the second substrate 8 side, a material having a high visible light transmittance is used as the material of the second substrate.

The second electrode 6 may be made of any conductive material that can be patterned. In the case of a transparent electrode, ITO or the like is used. Note that, if necessary, an insulating layer (not shown) may be formed on the second electrode 6 so that the entire surface becomes smooth.

Next, as shown in FIG. 5B, a tube 4 enclosing the dispersion system 3 is arranged on the first substrate 7. As the material of the first substrate 7, the same material as that of the second substrate 8 is used.
When the display device is observed from the first substrate side, a display device having a high visible light transmittance is used. If necessary, a supporting material such as a silicone resin or an acrylic resin may be provided on the adjacent tube 4.
And between the tube 4 and the first substrate 7 or the second substrate 8.

In the present invention, when disposing the tube 4 on the first substrate 7, the first electrode 5 formed on the surface of the tube 4
It is arranged so as to be in contact with the substrate 7. In the case of a color display, the tubes 4 in which charged particles 2 or insulating liquids 1 of different colors are sealed are arranged as appropriate, for example, in the order of yellow, magenta, and cyan.

Next, as shown in FIG. 5C, the second substrate 8 on which the second electrode 6 is formed is separated from the first electrode 5 and the second electrode 6.
Are arranged above the tube 4 in a direction orthogonal to the first substrate 7.
And after that, if the above-mentioned support material was used, it was cured, and if the support material was not used,
Alternatively, even in the case where the first substrate 7 and the second substrate 8 are used, the first substrate 7 and the second substrate 8 are bonded by applying a light-curing or thermosetting adhesive to the outer peripheral portion as necessary. At this time, the tube 4 is deformed in accordance with the distance between the substrates 7 and 8, and the tubes can be arranged in close contact with no gap as shown in FIG.

When the tube 4 is made of a material having low or no flexibility, a tube 4 having a final sectional shape shown in FIG. 5D may be prepared.

FIG. 5E is a partial sectional view of the tube 4 in the longitudinal direction. In the present embodiment, the partition walls 10 do not come into contact with each other vertically, and thus the moving ranges of the adjacent charged particles 2 separated by the partition walls 10 are in communication with each other. Alternatively, the moving ranges may be individually closed.

Finally, a means (not shown) for applying a voltage between the first electrode 5 and the second electrode 6 is provided to obtain the display device of the present invention.

Next, after the dispersion system 3 is sealed in the light-transmitting tube 4 on which the first electrode 5 is formed, the partition wall 10 is formed on the inner wall surface of the tube 4.
An example of forming is described with reference to FIG.

First, the second electrode 6 is formed on the surface of the second substrate 8 in the same manner as in the step of FIG.

Next, a first electrode 5 is formed on the light-transmitting tube 4 having flexibility in the same manner as in the above-described embodiment.
Enclose dispersion 3. Further, a convex portion 61 having a shape corresponding to the shape of the partition wall 10 to be formed in advance is formed outside the tube 4. At this time, a convex portion may be provided inside the tube 4, but in this case, it is formed at a position corresponding to the outer convex portion 61. The projection 61 may be formed of the same material as the tube 4 and can be formed integrally with the tube 4 at the same time as the tube 4 is formed. Further, the convex portion 61 formed of another material may be fixed to the outside of the tube 4. In this case, the material of the convex portion 61 is preferably selected from, for example, the materials listed above as the material of the tube 4.

The tube 4 is placed on the first substrate 7 as shown in FIG.

Next, as in the step of FIG.
After the second substrate 8 on which the electrodes 6 are formed is arranged above the tube 4 in a direction where the first electrodes 5 and the second electrodes 6 are orthogonal to each other, the first substrate 7 is aligned with the first substrate 7. And the second substrate 8 are bonded. As in the previous embodiment, the tube 4 is deformed in this step, but at this time, the projections 61 formed on the outside of the tube 4 are pushed into the inside of the tube 4, whereby the partition wall 10 is formed on the inner wall surface of the tube 4. Is formed (FIG. 5D).

In the present invention, the charged particles 2 can be easily and uniformly dispersed by enclosing the dispersion system 3 in a light transmissive tube 4 and disposing the tubes 4 between a plurality of substrates. In addition, charged particles 2 and insulating liquid 1 are applied to a minute area.
No complicated steps such as uniform dispersion of

Further, in the present invention, since the movement of the charged particles 2 is restricted by the partition walls 10 even in the tube 4, the bias of the charged particles 2 is greatly reduced even when the display device is used for a long time. And the occurrence of display unevenness can be suppressed.

In the above embodiment, the light transmitting tube 4
Is formed of a flexible material, and when the first substrate 7 and the second substrate 8 are bonded to each other, the tube 4 is deformed and brought into close contact, but a tube 4 having a rectangular cross section can also be used. . In this case, the arrangement of the tube 4 on the first substrate 7 is easy.

Further, since the first electrode 5 is formed directly on the surface of the tube 4 and then disposed between the substrates, even when the tube 4 is formed of a highly flexible material, the first electrode 5 and the second electrode 6 are formed. Is less likely to occur in the relative position between the first electrode 5 and the second electrode 6 than in the case where the first and second substrates are formed on the first substrate 7 and the second substrate 8, respectively. Can be prevented.

[0059]

(Example 1) A light-transmitting tube made of PET is partially heated at a fixed period, and a part of the tube is heated and shrunk to form a partition on the inner wall surface of the tube. A first electrode was formed in the tube and the dispersion was encapsulated.

The above tube has a circular cross section and an inner diameter of φ200 μm.
m, the thickness was 10 μm, and the partition walls were formed every 180 μm over the entire inner wall surface of the tube so that the inner diameter at the position where the partition walls were located was 100 to 150 μm.

As the first electrode, Al having a width of 100 μm and a thickness of 0.2 μm was vacuum-deposited in parallel with the longitudinal direction of the tube.

As the dispersion system, silicone oil in which a lipophilic white dye is dissolved is used as the insulating liquid, and black particles having a particle size of 1 μm to 2 μm made of a mixture of polystyrene and carbon are used as the charged particles. What was mixed so that it might be set to mass% was used. As a method for filling the dispersion system, as shown in FIG. 4 (a), put the black particles and silicone oil in an appropriate container, put one end of the tube into the dispersion system while stirring well, and place the other end in the dispersion system. And filled while sucking. After the filling was completed, both ends of the tube were closed by heating and sealed.

On a light-transmitting second substrate made of a PET film having a thickness of 200 μm, a 0.3 μm-thick second electrode was formed.
m of ITO was formed and patterned by photolithography and dry etching into a stripe shape having a width of 140 μm and a pitch of 150 μm.

On a first substrate made of PET having a thickness of 200 μm, a plurality of tubes enclosing the above-mentioned dispersion system were arranged so that the first electrode formed on the surface of the tubes was in contact with the first substrate.

Further, the second substrate is placed on the tube so that the second electrode is in contact with the tube and the first electrode and the second electrode are orthogonal to each other. After the positioning, an outer frame made of PET film is arranged on the outer peripheral portion, the distance between the substrates is set to 170 μm, and a casting polypropylene-based thermosetting adhesive is provided between the first substrate, the second substrate, and the outer frame. Was applied and heat-treated at 100 ° C. for adhesion. Thereby, the upper and lower portions of the tube came into contact with the substrate and became smooth, and the tubes were arranged in close contact with no gap. Finally, a voltage applying means was provided to obtain a display device.

Display was performed using the obtained display device.
The observation was performed from the second substrate side, and the applied voltage was ± 50 V. In the display device of this example, since the charged particles were positively charged in the silicone oil, they moved on the electrode to which a negative voltage was applied. Therefore, when a negative voltage was applied to the first electrode, the black charged particles moved on the first electrode, and the display surface became white. On the other hand, when a negative voltage was applied to the second electrode, the display surface became black because the black charged particles moved on the second electrode. The response speed at this time is 3
0 ms or less. No display unevenness due to uneven distribution of the charged particles was observed.

Example 2 A first electrode was formed on the outside of the tube used in Example 1 by a printing method to have a width of 100 μm and a thickness of 10 μm.
After forming the Ag electrode in a line shape of m, convex portions having a pitch of 300 μm and a film thickness of about 30 μm were formed on the outside of the tube at a pitch of 300 μm in a position where there was no electrode as shown in FIG. Next, the dispersion used in Example 1 was filled and sealed by the method shown in FIG.

The second substrate is formed on the second substrate in the same manner as in the first embodiment.
After the electrodes were formed, a plurality of tubes enclosing the above-mentioned dispersion system were arranged on the same first substrate as in Example 1. A second substrate is placed thereon such that the second electrode is on the tube side, and PE is
An outer frame made of a T film is arranged, and the distance between the substrates is set to 0.
A heat treatment was performed at 2 mm, and the first substrate and the second substrate were bonded and fixed. Thereby, the upper and lower portions of the pipes are in contact with the substrate and become smooth, the pipes are arranged in close contact with no gap, and the inner wall surface of the pipe on the side where the pipes contact each other is pressed by a convex portion formed on the outside of the pipe. Was formed.

When a display was performed in the same manner as in Example 1 using the obtained display device, good display was obtained as in Example 1, and the response speed was 30 ms or less. No display unevenness due to uneven distribution of the charged particles was observed.

(Example 3) A light-transmitting tube made of PET having a cross section of 200 μm on a side and a rounded corner and a thickness of 8 μm made of PET is partially subjected to a heat treatment, and is thermally shrunk. 30μm height, 250μ pitch in the longitudinal direction of the tube
m partition walls were formed over the entire circumference.

Then, an ITO electrode was formed in a line shape having a width of 100 μm and a thickness of 0.3 μm in parallel with the longitudinal direction of the tube by an ion plating method, and used as a first electrode. Also,
The longitudinal pitch is 2 outside the tube opposite the first electrode.
50 μm, 150 × 150 μm square thickness 0.2
A μm Al conductive film was formed.

The dispersion system used in Example 1 was sealed in the light-transmitting tube in the same manner as in Example 1. Then, Example 1
A plurality of the tubes are arranged on the same first substrate as above, a second substrate on which the same second electrode as that of Example 1 is formed is placed, the distance between the substrates is 220 μm, an outer frame made of PET is arranged, and heat treatment is performed. Then, the first substrate and the second substrate were bonded and fixed. Finally, a voltage applying means was provided to obtain a display device.

Using the display device thus obtained, display was performed in the same manner as in Example 1 with the first substrate side as the observer side. Good display similar to that in Example 1 was obtained. The response speed was 30 milliseconds or less. No display unevenness due to uneven distribution of the charged particles was observed.

(Example 4) The tube used in Example 1 was partially heated so that the inner diameter at a position where a partition wall was located at a pitch of 200 µm in the longitudinal direction of the tube was 100 to 150 µm. A partition was formed all around the inner wall surface.

Next, a Pt electrode having a width of 100 μm and a thickness of 0.2 μm was formed as a first electrode by sputtering.

As a dispersion system, a dye is dissolved in silicone oil as an insulating liquid, and three kinds of liquids colored in yellow, magenta and cyan colors, and fine particles of titanium oxide having a particle diameter of 1 μm to 2 μm as charged particles. Was used.
As a method for filling the tubes, the method shown in FIG. 4B was used, and the tubes were filled into separate tubes for each color so that the above-mentioned white fine particles became 2% by mass in the dispersion system. After filling, both ends of the tube were heated and sealed.

A plurality of the above tubes were arranged in the same manner as in Example 2 so that yellow, magenta, and cyan were regularly arranged.
The first substrate and the second substrate are arranged on the substrate in the same manner as in the second embodiment.
The substrate was bonded and fixed. Finally, a display device was manufactured by providing voltage applying means.

Using the obtained display device, display was performed with the applied voltage ± 50 V with the second substrate side as the observation side. In the display device of this embodiment, since the charged particles were negatively charged in the silicone oil, they moved to the electrode side to which a positive voltage was applied, and when a positive voltage was applied to the first electrode, the display surface was The color of each insulating liquid was displayed, and when a positive voltage was applied to the second electrode, the display surface displayed white. Therefore, color display can be performed by combining the display of yellow, cyan, and magenta by the combination of the voltages applied to the first electrode and the second electrode. The response speed was 30 ms or less, and no display unevenness due to uneven distribution of the charged particles was observed.

(Example 5) Silicone oil in which a lipophilic white dye was dissolved as an insulating liquid, and polystyrene and yellow, magenta, and cyan colors were charged as charged particles in the light-transmitting tube used in Example 1. A dispersion system composed of three colored particles having a particle size of 1 μm to 2 μm mixed with the agent was separately sealed in a different tube for each color. As a method for filling the dispersion system, the method shown in FIG. 4B was used.

Then, the center of the tube is heated using a jig,
Pressing is performed while applying pressure, so that a part of the inner wall surface of the tube is in contact with the inner wall surface of the tube so that the pitch in the longitudinal direction of the tube is 200 μm and the inner diameter of the position where the partition wall is located is 50 to 100 μm. A partition was formed. Further, a line-shaped Ag electrode having a width of 100 μm and a thickness of 0.2 μm parallel to the longitudinal direction of the tube was formed outside the tube.

Next, a second electrode was formed on the second substrate in the same manner as in Example 1.

A plurality of tubes of three colors were arranged on the same first substrate as in Example 1 so that yellow, magenta, and cyan were regularly arranged. The second substrate was mounted thereon in the same manner as in Example 1, and the distance between the substrates was set to 200 μm, and the first substrate and the second substrate were bonded and fixed. Finally, a voltage applying means was arranged to obtain a display device.

Using the obtained display device, display was performed with the second substrate side as the observation side and an applied voltage of ± 50 V. In the display device of the present embodiment, since the charged particles were positively charged in the silicone oil, the charged particles moved to the electrode side to which a negative voltage was applied, and when a negative voltage was applied to the first electrode, the display surface showed The color of each insulating liquid was displayed, and the display surface was white when a negative voltage was applied to the second electrode. Therefore, color display can be performed by combining the display of yellow, cyan, and magenta by the combination of the voltages applied to the first electrode and the second electrode. The response speed was 30 ms or less, and no display unevenness due to uneven distribution of the charged particles was observed.

Example 6 The inner diameter of the tube was 30 μm, the distance between the substrates was 25 μm, and the particle size of the charged particles was 0.5 μm to 1 μm.
A display device was produced in the same manner as in Example 1 except that the value was changed to m, and the display was performed with an applied voltage of ± 50 V.

In the display device of this embodiment, since the moving distance of the charged particles was short, the response speed was 5 milliseconds or less, and high-speed response was possible. No display unevenness due to uneven distribution of the charged particles was observed.

[0086]

As described above, according to the present invention,
A display device in which charged particles are uniformly dispersed and which has no display unevenness can be easily obtained, and the manufacturing cost can be reduced, and the manufacturing yield can be improved. Further, according to the present invention, since the possibility that the relative position between the two electrodes is shifted is reduced, a display device with less display unevenness can be obtained.

Further, in the present invention, even when used for a long time, the occurrence of display unevenness due to uneven distribution of the charged particles is greatly reduced, and a display device with higher durability is provided.

Therefore, according to the present invention, either a binary display or a color display is possible, and a display device having a high viewing angle and a high contrast can be realized at a lower cost.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically illustrating a configuration of an embodiment of a display device of the present invention.

FIG. 2 is a schematic partial cross-sectional view of the display device of FIG.

FIG. 3 is a diagram showing a state in which a first electrode is formed on a light transmitting tube used in the present invention.

FIG. 4 is a schematic view showing a method for filling a light-transmissive tube with a dispersion system in the method of manufacturing a display device of the present invention.

FIG. 5 is a process chart of one embodiment of a method for manufacturing a display device of the present invention.

FIG. 6 is a process chart of another embodiment of the method of manufacturing the display device of the present invention.

FIG. 7 is a diagram showing a basic configuration of a conventional electrophoretic display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating liquid 2 Charged particle 3 Dispersion system 4 Light transmission tube 5 1st electrode 6 2nd electrode 7 1st substrate 8 2nd substrate 9 Conductive film 10 Partition wall 41 Container 61 Convex part 71 Insulating liquid 72 Charged particle 73 dispersion system 75,76 electrode 77,78 substrate 79 outer frame

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Matsuda 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Tsutomu Ikeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated F term (reference) 5C094 AA03 AA22 AA31 BA09 BA76 BA84 BA93 CA19 CA24 GB01

Claims (19)

[Claims] A first substrate and a second substrate which are arranged to face each other;
A substrate, a dispersion system in which charged particles are dispersed in an insulating liquid sandwiched between the substrates, and at least a first electrode and a second electrode for applying a voltage to the dispersion system, A display device for performing display by moving the charged particles in the direction of the first electrode or the second electrode by a voltage applied between a first electrode and a second electrode, wherein the dispersion system is provided between the substrates. Are filled in a light-transmissive tube made of an insulating material arranged in parallel with a plurality of the tubes, and the tube is provided with a partition wall protruding on an inner wall surface in a direction perpendicular to the longitudinal direction of the tube in a regular manner in the longitudinal direction of the tube. A first electrode having a line shape parallel to the longitudinal direction of the tube is formed between each tube and the first substrate for each tube, and a second electrode is formed between the tube and the second substrate. A display device characterized by being performed. 2. The display device according to claim 1, wherein one of the first electrode and the first substrate or one of the second electrode and the second substrate is light-transmissive. 3. The display device according to claim 1, wherein a conductive film is formed between the second electrode and the tube. 4. The display device according to claim 1, wherein the charged particles move vertically between the first electrode and the second electrode within a range defined by the partition. 5. The display device according to claim 1, wherein a partition wall is formed on a side surface of the light transmitting tube perpendicular to the substrate. 6. The light-transmitting tube is made of resin.
6. The display device according to any one of 5. 7. The light-transmitting tube has flexibility.
7. The display device according to any one of claims 6 to 6. 8. The display device according to claim 1, wherein the insulating liquid and the charged particles have different colors. 9. The display device according to claim 8, wherein one of the insulating liquid and the charged particles is colored one of yellow, magenta, and cyan for each tube. 10. The display device according to claim 9, wherein the tubes are arranged so that yellow, magenta, and cyan are regularly arranged. 11. The display device according to claim 1, wherein the second electrode is formed in a stripe shape orthogonal to the tube, and the first electrode and the second electrode form a matrix. 12. The method for manufacturing a display device according to claim 1, wherein a first linear line parallel to the longitudinal direction of the tube is provided outside the light-transmitting tube made of an insulating material. A step of forming an electrode, and a step of regularly forming, in the longitudinal direction of the tube, partition walls projecting in a direction perpendicular to the longitudinal direction of the tube on the inner wall surface of the light-transmitting tube made of an insulating material; Enclosing a dispersion system in which charged particles are dispersed in an insulating liquid in a light-transmissive tube made of an insulating material; A step of arranging and fixing the first electrode in contact with the first substrate and the second electrode in contact with the tube between the second substrate on which the two electrodes are formed and the first substrate. A method for manufacturing a display device, comprising: 13. The method for manufacturing a display device according to claim 12, wherein the insulating liquid and the charged particles are simultaneously filled in a light transmissive tube. 14. The method for manufacturing a display device according to claim 12, wherein the insulating liquid and the charged particles are individually filled in a light transmissive tube. 15. The method according to claim 12, wherein a cross section of the light-transmitting tube is rectangular. 16. The light transmitting tube according to claim 12, wherein the light transmitting tube has flexibility, and when the light transmitting tube is fixed between the first substrate and the second substrate, the cross section of the tube is deformed to bring the tubes into close contact with each other. A method for manufacturing a display device according to any one of the above. 17. The light-transmitting tube is made of a heat-shrinkable material, and the partition is formed by heat shrinkage.
7. The method for manufacturing a display device according to any one of 6. 18. The method for manufacturing a display device according to claim 12, wherein the partition wall is formed by press-forming the light-transmitting tube using a jig. 19. A convex portion is formed outside the light-transmitting tube,
17. The method for manufacturing a display device according to claim 16, wherein when the tube is fixed between the first substrate and the second substrate, a partition is formed in the tube by pressing the projection into the tube.