JP3466964B2 - Display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device,
In particular, the present invention relates to an electrophoretic display device that displays by moving charged particles in a liquid by a voltage applied to an electrode.

[0002]

2. Description of the Related Art In recent years, with the development of information equipment, the need for low power consumption and thin display devices has increased, and research and development of display devices meeting these needs have been actively conducted. Among them, the liquid crystal display device can change the optical characteristics of the liquid crystal by electrically controlling the alignment of liquid crystal molecules, and is actively developed and commercialized as a display device that can meet the above needs. ing.

However, in this liquid crystal display device, it is difficult to see the characters on the screen due to the angle of viewing the screen and the reflected light.
The visual burden caused by the flicker and low brightness of the light source has not been sufficiently solved. For this reason, researches on display devices with less burden on the eyes are being actively studied.

Therefore, a reflective display device is expected from the viewpoint of such low power consumption and reduction of burden on the eyes, and an electrophoretic display device is known as one of them.
Here, in this electrophoretic display device, as shown in FIG. 13, a dispersion layer including charged electrophoretic particles 31 and an insulating liquid 32, and a pair of electrodes 33 and 3 facing each other with the dispersion layer interposed therebetween.
4 is provided, and by applying a voltage to the dispersion layer through the electrodes 33 and 34, the electrophoretic particles 31 are attracted to the side opposite to the electric charge of the particles themselves.

By the way, this electrophoretic display device can perform color display by coloring the electrophoretic particles 31 and the insulating liquid 32. That is, when the colored electrophoretic particles 31, which are the colored charged particles, adhere to the surface of the first electrode 33 close to the observer as shown in (b) of the figure, the color of the electrophoretic particles 31 is displayed. To (a)
As shown in (3), when it adheres to the second electrode surface 34 far from the observer, the color of the dyed insulating liquid 32 is displayed.

As another type of electrophoretic display device, a pair of electrodes are arranged adjacent to each other on one substrate, as proposed in, for example, Japanese Patent Application Laid-Open No. 49-24696. There is one in which the display is moved by moving in parallel to the substrate.

FIG. 14 is a diagram showing the structure of such an electrophoretic display device. In FIG. 14, 35 is a translucent electrode.
Reference numeral 36 denotes an opaque electrode, and the translucent electrode 35 and the opaque electrode 36 are arranged side by side on a support plate 37.

Here, for example, if the electrophoretic particles 31 are black and the support plate 37 is white, if the electrophoretic particles 31 adhere to the opaque electrode surface as shown in FIG.
Is transmitted through the transparent electrode 35 and reflected by the white support plate 37, so that the translucent electrode portion looks substantially white. Also,
As shown in (b), when the electrophoretic particles 31 adhere to the surface of the translucent electrode, the amount of reflected light is small and the particles appear black.

By the way, in the electrophoretic display device having such a structure, the electrophoretic particles 3 are repeatedly used for a long time.
The density distribution of 1 may be biased, resulting in display unevenness. Therefore, as a method for preventing such uneven distribution of concentration, for example, as disclosed in Japanese Patent Laid-Open No. 59-34518 or Japanese Patent Laid-Open No. 2-284124, partition walls are provided at regular intervals in the sealed portion. There is a method of forming and dividing into small sections.

Further, as proposed in Japanese Patent Laid-Open No. 1-114828, for example, a porous spacer composed of a member swelling with a dispersion medium is used, and after the dispersion system is injected, it is divided into discontinuous small sections. There is a way. Here, in this proposal, a plurality of light-transmissive tubes preliminarily filled with a liquid and electrophoretic particles are arranged between substrates, and since the tubes themselves can be partition walls, it is not necessary to form partition walls.

There is a liquid crystal display device proposed in Japanese Patent Laid-Open No. 49-96694 as a display device having a structure in which a light-transmitting tube is arranged between substrates. This has been proposed as a display device having a structure in which tubes filled with a liquid crystal material are arranged in parallel, having a uniform thickness, and capable of preventing the entry of moisture, gas, etc. from the outside.

[0012]

However, in such a conventional electrophoretic display device, as described above, in order to prevent display unevenness due to uneven concentration distribution of electrophoretic particles, the partition walls are spaced at regular intervals. In the case of forming, the electrophoretic particles had to be evenly distributed in each small section, which was difficult to distribute. Further, there is a problem that a lot of time and cost are required for a series of manufacturing steps that require formation of partition walls on the substrate, uniform distribution of electrophoretic particles and insulating liquid, and encapsulation.

Further, in the case of color display, since electrophoretic particles or insulating liquids of a plurality of colors are used, even if the partition is divided into small compartments, it is easy for colors to mix with each other in adjacent compartments at the time of manufacture. It was difficult to fill only the electrophoretic particles of color or the insulating liquid. Therefore,
There is a problem that color display is more difficult.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a (electrophoretic) display device capable of reducing display unevenness and manufacturing cost. To do.

[0015]

The present invention comprises colored charged particles dispersed in a transparent insulating liquid, and first and second electrodes for applying a voltage to the colored charged particles. A display device for displaying by moving the colored charged particles in the direction of the first electrode or the second electrode by a voltage applied to one electrode and a second electrode, wherein the transparent insulating liquid and the colored charged particles are While filling the tube having a light-transmitting property, a convex portion that blocks the movement of the colored charged particles is regularly formed on the inner wall surface of the tube in the longitudinal direction of the tube, and the tubes are connected to each other by the first electrode and the first electrode. It is characterized in that it is disposed in close contact between the first substrate on which the second electrode is formed and the second substrate.

In the present invention, the colored charged particles may have a range defined by the two adjacent convex portions in the tube, which are defined by the voltage applied to the first and second electrodes. It is characterized in that it moves parallel to the second substrate.

The present invention is also characterized in that the convex portion is formed on an inner wall surface of the tube on the side of the first substrate on which at least the first and second electrodes are formed.

The present invention is also characterized in that the tube is made of a polymer.

The present invention is also characterized in that the convex portion of the tube is formed by heating and shrinking the tube before filling the transparent insulating liquid and the colored charged particles. is there.

In the present invention, the convex portion of the tube may be filled with the transparent insulating liquid and the colored charged particles before or after the filling.
It is characterized in that it is formed by press-molding the tube.

According to the present invention, when the convex portion of the tube is filled with the transparent insulating liquid and the colored charged particles and then the tube is placed in close contact with the first and second substrates, It is characterized in that it is formed by pressing the tube by a convex structure formed at least on the first substrate.

Further, the present invention is characterized in that the first electrode has a light-transmitting property, and a coloring layer and a light-reflecting layer are laminated on the surface of the first substrate.

Further, the present invention is characterized in that the first electrode or the colored layer and the light reflection layer laminated on the surface of the first electrode are colored in a color different from that of the colored charged particles. .

Further, in the present invention, the transparent insulating liquid is colored in a color different from that of the colored charged particles, and a tube filled with the insulating liquid of the different color is provided between the first substrate and the second substrate. It is characterized by being arranged regularly.

The present invention is also characterized in that the tubes filled with the colored charged particles of different colors are regularly arranged between the first substrate and the second substrate.

Further, the present invention is characterized in that the second electrode is colored.

Further, the present invention is characterized in that at least one of the first and second substrates has a light transmitting property.

The present invention is also characterized in that the first substrate and the second substrate are polymer films.

Further, according to the present invention, color display is performed by using any one of the color of the colored charged particles, the color of the electrode, the color of the insulating liquid, the color of the coloring layer and the color of the light reflecting layer. It is a feature.

As in the present invention, a transparent insulating liquid,
A tube having light transmissivity is filled with colored charged particles that move in the direction of the first electrode or the second electrode by the voltage applied to the first electrode and the second electrode, and the colored charged particles are attached to the inner wall surface of the tube. By regularly forming the convex portions for preventing the movement of the colored particles in the longitudinal direction, the colored charged particles are moved within the range defined by the two adjacent convex portions.
Further, by arranging the tubes filled with the transparent insulating liquid and the colored charged particles in close contact with each other between the first substrate and the second substrate on which the first and second electrodes are formed, Make sure that the charged particles are evenly dispersed.

[0031]

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

FIG. 1 is a perspective view of an electrophoretic display device which is a display device according to an embodiment of the present invention, and FIG. 2 is a view showing a part of its cross section.

In FIGS. 1 and 2, 1 is a transparent insulating liquid, 2 is colored charged particles, 3 is a light-transmissive tube in which the transparent insulating liquid 1 and the colored charged particles 2 are enclosed, 4, 6
Are first and second substrates holding the tube 3 therebetween. Further, 5 is an insulating layer formed on the first substrate, and the tube 3 is an insulating layer 5
And the second substrate 6 are held. A second electrode 7 is partially formed under the insulating layer 5, and a first electrode 8 is further formed below the second electrode 7.

In this electrophoretic display device (hereinafter, referred to as a display device), colored charged particles 2 which are electrophoretic particles charged in a transparent insulating liquid are parallel to the substrate surface, on the first electrode surface, or. Is displayed by moving it onto the surface of the second electrode. For example, as shown in FIG. 2A, the colored charged particles 2 in the transparent insulating liquid are applied to the first electrode 8 by applying a voltage. When collected on the first electrode, the colored charged particles 2 and the second electrode 7 are observed (displayed) from an observer (second substrate side).
To be done. On the other hand, when the colored charged particles 2 are collected on the second electrode by changing the polarity of the voltage as shown in FIG. 2B, the colored charged particles 2 and the insulating layer 5, the first electrode 8 or the first substrate 4 are collected.
A colored layer is observed.

Then, by configuring in this way,
For example, both the second electrode 7 and the colored charged particles 2 are black,
If the first electrode 8 is white, black and white display is possible. Further, as described later, color display can be performed by appropriately disposing colored tubes 2 in which different colored colored charged particles 2 and transparent insulating liquid 1 are enclosed, or by providing colored layers.

As an arrangement method of the tube 3, there is a method of arranging the tube 3 in parallel with the second electrode 7 as shown in FIG. 2, and in this arrangement method, the colored charged particles 2 have the same shape as shown in FIG. And, as shown in (b), the pipe 3 moves in the lateral direction which is a direction orthogonal to the longitudinal direction. On the other hand, as another arrangement method, there is a method of arranging the tube 3 in parallel with the first electrode 8 as shown in FIG. 3, and in this arrangement method, as shown in (a) and (b) of FIG. The particles 2 move in the longitudinal direction of the tube 3.

By the way, the inner wall surface of the pipe 3 is shown in FIG.
As shown in FIG. 3, convex portions 3a for partitioning the pipe 3 are regularly formed in the longitudinal direction. By forming such convex portions 3a on the inner wall surface of the pipe 3, the convex liquid 3a is repeatedly moved in the insulating liquid. It is possible to limit the moving range of the colored charged particles 2 to be within a space range (hereinafter, referred to as a moving space) partitioned by two adjacent convex portions 3a.

By limiting the moving range of the colored charged particles 2 in the moving space in this manner, the colored charged particles 2 can be uniformly arranged at the time of manufacturing, and the colored charged particles 2 can be used for a long time. Can be reduced.
Further, this makes it possible to reduce display unevenness.

In the present embodiment, the convex portion 3a is formed over the entire inner wall surface of the tube 3. However, if the movement of the colored charged particles 2 can be restricted, the convex portion 3a can be formed, for example, in the tube 3. It may be provided only on the inner wall surface of the first substrate side on which the electrodes 7 and 8 are provided. Further, the moving space S may be completely sealed by the two adjacent convex portions 3a so as to limit the movement of not only the colored charged particles 2 but also the transparent insulating liquid 1.

By the way, the convex portion 3a may be formed on the inner wall surface of the tube 3 before the colored charged particles 2 and the transparent insulating liquid 1 are filled therein, or the colored charged particles 2 and the transparent insulating liquid 1 may be formed. It may be formed after 1 is filled.

Here, when the convex portion 3a is formed before filling the colored charged particles 2 and the transparent insulating liquid 1, for example, the tube 3 is heated or irradiated with light to shrink the tube 3, or The tube 3 is formed by periodically deforming the tube 3 by press molding with a jig. The diameter of the tube 3 and the pitch and size of the convex portions 3a that are periodically formed are appropriately determined according to the size of the display pixel.

When the convex portion 3a is formed after filling the colored charged particles 2 and the transparent insulating liquid 1, for example, the tube 3 filled with the colored charged particles 2 and the transparent insulating liquid 1 is
It is formed by pressing the convex structure formed on the first substrate or a part of the electrode. Further, it is possible to use a method such as press molding using a jig or physical twisting.

On the other hand, the cross-sectional shape of the tube 3 having such a convex portion 3a is basically not particularly limited as long as it does not hinder the movement of the colored charged particles 2 in the moving space, and is circular or elliptical. However, in order to realize a display that is easy for an observer to see and has little unevenness, it is desirable that the display area is large and the movement of the colored charged particles 2 is uniform. Therefore, when the inner diameter of the tube 3 in the direction perpendicular to the substrates 4 and 6 is 1, the inner diameter in the direction parallel to the substrates 4 and 6 is preferably 1 or more.

By the way, in such a display device,
By using the transparent insulating liquids 1 of a plurality of colors, the colored charged particles 2 of a plurality of colors, and further by forming a colored layer on the first substrate 4, color display can be performed.

Next, a display device capable of such color display will be described.

FIG. 4 is a cross-sectional view of a display device for performing color display by using transparent insulating liquids of a plurality of colors. In this display device, coloring is performed as shown in (a) and (b) of FIG. A tube 3 in which charged particles 2 and transparent insulating liquids 10, 11, and 12 of yellow (Y), magenta (M), and cyan (C) colors are enclosed is regularly arranged. Further, the colored charged particles 2 are white and the first electrode 8 is a translucent electrode, while the first substrate 4 is light transmissive so that the display is observed from the first substrate side. In the figure, 3a 'indicates a convex portion provided only on the inner wall surface of the tube 3 on the side of the first substrate on which the electrodes 7 and 8 are provided.

Here, for example, the display of yellow (Y) is
The colored charged particles 2 in the tube in which the yellow (Y) transparent insulating liquid 10 is filled are collected on the second electrode, and the other magenta (M) and cyan (C) transparent insulating liquids 11 and 12 are filled. This is possible by collecting the colored charged particles 2 in the tube on the first electrode.

In addition, as shown in the figure, yellow (Y),
Magenta (M), cyan (C) transparent insulating liquid 10,
White can be displayed by collecting all the colored charged particles 2 in each tube in which 11 and 12 are enclosed on the first electrode, while black can be displayed by collecting all the colored charged particles 2 on the second electrode. Can be displayed.

FIG. 5 is a sectional view of a display device for performing color display using colored charged particles of a plurality of colors. In this display device, as shown in FIG. ), Magenta (M) and cyan (C) colored charged particles 13, 14 and 15 are regularly arranged. Furthermore, the first electrode 8 is white, or a white colored layer (not shown) is provided between the first electrode 8 and the second electrode 7, and the second substrate 6 is light transmissive.
The display is observed from the second substrate side. In this case, it is desirable that the light shielding portion 16 corresponding to the second electrode 7 on the second substrate be colored white or black.

Here, for example, the display of yellow (Y) is
The colored charged particles 13 of yellow (Y) are collected on the first electrode, and the colored charged particles 1 of magenta (M) and cyan (C) are collected.
This is possible by collecting 4, 15 on the second electrode.
In addition, as shown in the figure, colored charged particles 13, 14, 15
Black can be displayed by collecting all on the first electrode,
On the contrary, if all the colored charged particles 13, 14, 15 are collected on the second electrode, white can be displayed.

FIG. 6 is a cross-sectional view of a display device for performing color display by forming a colored layer on the first substrate 4. In this display device, a first substrate and a first electrode having light transmissivity are used. At the same time, as shown in the figure, a yellow (Y) color different from the color of the colored charged particles 2 is provided above the first electrode 8,
Magenta (M) and cyan (C) colored layers 17, 18, 1
9 is formed. The colored layers 17, 18, 19
The formation position may be formed on the first electrode 8, between the first substrate 4 and the insulating layer 5, or on the back surface of the first substrate, as long as it can be observed from the observer side (second substrate side). . Further, it may be formed on the entire surface or in a part of each place. Further, a colored or non-colored light reflecting layer (not shown) may be formed below the colored layers 17, 18 and 19.

Then, for example, as shown in FIG.
Yellow (Y), magenta (M) and cyan (C) colored layers 17, 18 and 19 are regularly formed on the colored colored particles 2 and the colored charged particles 2 are made white, while the colored charged particles 2 are colored as described above. A desired color can be displayed by moving.

In the above color display, the color of the colored charged particles 2, 13, 14, 15 and the first electrode 8, the insulating layer, etc. may be the color of the material itself, and other materials may be applied to the surface of those materials. It may be laminated or mixed. The colored charged particles 2, 13, 14, 15 may be made of one kind or two or more kinds of materials. Further, here, the color display is three colors of yellow (Y), magenta (M), and cyan (C), but depending on the display environment and the display image, there is no particular focus on these, and if necessary, any color, or Color display using ultraviolet light and infrared light is also possible.

Further, in the present display device, since the colored charged particles 2 are horizontally moved in the lateral direction with respect to the display surface, it is possible to structurally express the gradation of the display color. That is, for example, as shown in FIG. 7A, the colored charged particles 2 on the second electrode are
This can be achieved by partially moving to the first electrode 8 as shown in (b). As a method of moving a part of the colored charged particles 2 as described above, the voltage application time is shortened, the applied voltage is reduced, particles having different charging capacities are mixed and used, and particles having different sizes are mixed. And then use it.

Next, the manufacturing process of such a display device will be described.

First, a case will be described in which the light-transmitting tube 3 in which the convex portion 3a is already formed on the inner wall surface is used by the method described above.

In this case, first, a colored tube and a transparent insulating liquid are filled with colored charged particles. In this embodiment, this tube has a circular or elliptical cross section, and the material of the tube is acrylic resin, polystyrene, polyethylene terephthalate (PET), polyether having a high visible light transmittance. Sulfone (PE
Polymers such as S) or inorganic materials such as glass and quartz can be used, but polymers having high flexibility are particularly preferably used. The diameter of the tube is appropriately determined according to the size of the display pixel.

On the other hand, as the transparent insulating liquid, a colorless transparent liquid such as silicone oil, toluene, xylene, and high-purity petroleum is used. When the transparent insulating liquid is colored for color display, it is used as a coloring material. A dye or the like is used by being dissolved or dispersed in the transparent insulating liquid.

As the colored charged particles, a material which can be charged in a transparent insulating liquid is used. For example, titanium oxide (white), aluminum oxide (white), or a resin such as polyethylene or polystyrene mixed with a coloring agent is used.
Here, as the colorant, well-known dyes and pigments such as carbon (black), for example, phthalocyanine blue, induslen blue, peacock blue, permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow, benzine yellow, etc. are widely used. be able to. The particle size is usually 0.1 μm.
The thing of about 50 μm is used.

As a method for filling the tube 3 with the colored charged particles and the transparent insulating liquid, for example, as shown in FIG. 8A, the transparent insulating liquid 1 and the colored charged particles 2 are put in a suitable container 21. In the method, one end of the tube 3 is put in the liquid while being well stirred, and the other end is sucked and filled at the same time, or as shown in FIG. After applying evenly, the transparent insulating liquid 1
Charged colored particles 2 and transparent insulating liquid 1
There is a method of separately filling and in the tube 3.

After the colored charged particles 2 and the transparent insulating liquid 1 are filled by these methods, both ends of the tube 3 are closed by heating or the like and sealed.

Next, this tube 3 is placed between the substrates according to the process shown in FIG. That is, first, the first electrode 8 is patterned on the first substrate 4 as shown in FIG. The material of the first substrate 4 is a material having high visible light transmittance and high heat resistance, such as polyethylene terephthalate (PET) or polyether sulfone (PE).
Polymer films such as S) or inorganic materials such as glass and quartz can be used. The first electrode 8 may be made of any conductive material that can be patterned, and if the first electrode 8 is a transparent electrode, indium tin oxide (ITO) or the like is used.

Next, after forming a part of the insulating layer on the first electrode, the second electrode 7 is formed on the insulating layer so as to be orthogonal to the first electrode 8, and thereafter, ( As shown in b), the insulating layer 5 is formed so as to cover the second electrode 7. In addition,
The insulating material for forming the insulating layer 5 is preferably a thin film in which it is difficult to form pinholes. For example, highly transparent polyimide or PET is used. The forming material of the second electrode 7 is the same as that of the first electrode 8.

Furthermore, in order to form a display color on the substrate portion, the color of the electrode material or the insulating layer material itself may be used as described above, or a material layer of a desired color may be formed on the electrode by insulation. It may be formed on the layer or on the surface of the substrate. Further, a coloring material may be mixed in the insulating layer 5 or the like.

Next, as shown in (c), the tube 3 filled with the colored charged particles 2 and the transparent insulating liquid 1 is arranged on the first substrate 4 having the insulating layer 5 formed on the surface thereof. . In the case of color display, the tubes 3 containing the colored charged particles 2 or the transparent insulating liquid 1 of different colors are properly regularly arranged, for example, in the order of yellow (Y), magenta (M), cyan (C). To place.

Next, as shown in (d), the second substrate 6 is arranged above the tube 3 and then aligned with the first substrate 4, and thereafter, an outer frame (not shown) is formed at the outer peripheral portion. The first substrate 4 and the second substrate 6 are bonded to each other by applying heat via the. At this time, the tube 3 is deformed according to the distance between the two substrates 4 and 6, and as a result, the tubes can be arranged in close contact with each other without any gap as shown in (e). Finally, voltage applying means (not shown)
And the display device is manufactured.

When the first substrate 4 and the second substrate 6 are adhered to each other as shown in (e), the convex portions 3a periodically formed in the tube do not come into contact with each other vertically as shown in (f). However, the moving spaces adjacent to each other are communicated with each other, but the convex portions 3a may come into contact with each other vertically due to the deformation of the tube 3, or the moving space S may be closed. In any of these cases, display can be performed without any problem, and uneven distribution of the colored charged particles 2 can be prevented.

Next, the manufacturing process of the display device including the process of forming the convex portion 3a on the tube 3 after filling the colored charged particles 2 and the transparent insulating liquid 1 will be described.

First, charged particles and a transparent insulating liquid are filled in a transparent tube. At this time, the tube may have a convex portion or may not have a convex portion.

The tube is then placed on the substrate according to the process shown in FIG. That is, first, the first electrode 8 is patterned on the first substrate 4 as shown in FIG. Next, after forming a part of the insulating layer on the first electrode, the second electrode 7 is formed thereon so as to be orthogonal to the first electrode 8, and thereafter, as shown in (b). This second electrode 7
The insulating layer 5 is formed so as to cover the. The transparent insulating liquid 1, the charged particles 2, the tube 3, the first substrate 4, the insulating layer 5, the first and second electrodes 7 and 8 are the same as the colored charged particles 2 and the transparent insulating liquid described above. The same material as in the case of using the tube 3 in which the convex portion 3a is formed before filling 1 is used.

Next, the convex structure 9 for forming the convex portion 3a on the inner wall surface of the tube 3 is formed on the insulating layer 5. Here, as the material for forming the convex structure 9, it is easy to use the same material as the insulating layer 5 in terms of the process, but it is not always necessary to use the material showing the insulating property. It is also possible to make a part of the first and second electrodes 7 and 8 a convex structure. Further, the shape, arrangement, etc. of the convex structure 9 can be appropriately determined according to the specifications of the convex portion 3a inside the tube.

Next, as shown in (c), the tube 3 filled with the colored charged particles 2 and the transparent insulating liquid 1 is placed on the first substrate having the convex structure 9 formed on the surface thereof. After this,
Further, as shown in (d), the second substrate 6 is placed above the tube 3, and then the second substrate 6 is aligned with the first substrate 4, and heat is applied to the outer peripheral portion through the outer frame to bond them. Then, when the first and second substrates 4 and 6 are bonded in this way, the tube 3 is deformed, and the convex portion 3a is formed only on the first substrate side as shown in (e).

Although the convex structure 9 is formed only on the first substrate side here, the convex structure 9 may be provided on the second substrate side. Further, after being bonded via the outer frame, the pipe 3 may partially contact with the upper and lower parts by the convex structure 9 or may be completely closed. As described above, by forming the convex portion 3a at least on the side of the substrate where the colored charged particles 2 gather during the image display, the movement of the colored charged particles 2 can be limited, and the display unevenness can be reduced.

As another method for periodically dividing the tube 3 after filling the colored charged particles 2 and the transparent insulating liquid 1, a method such as press forming using a jig or physically twisting is possible. Is. In these cases, the portion of the tube 3 in which the transparent insulating liquid 1 and the colored charged particles 2 are narrowed is expressed as a convex portion 3a as viewed from the inside of the tube. Specifically, this corresponds to a press-molded portion and a twisted portion.

Also in these cases, the tube 3 may be closed at the portion where the transparent insulating liquid 1 and the colored charged particles 2 are narrowed. When the tube 3 is sectioned by increasing the temperature by press molding or the like, it is desirable to use a material whose softening temperature of the tube 3 is lower than the alteration temperature of the colored charged particles 2 and the transparent insulating liquid 1.

In this way, the transparent insulating liquid 1 and the colored charged particles 2 are filled in the light transmissive tube 3 and the tube 3
By arranging a plurality of them side by side, it is possible to easily uniformly disperse the colored charged particles 2 during manufacturing. Further, the time and labor-consuming steps such as the formation of the partition wall on the substrate and the uniform dispersion of the colored charged particles 2 and the transparent insulating liquid 1 in the minute area as described above are not required, so that the cost can be reduced. In addition to being realized, the yield can be improved.

Furthermore, since the colored charged particles 2 only move in the tube, the bias of the colored charged particles 2 can be reduced and the display unevenness can be prevented even when the display device is used for a long time. Furthermore, the display device manufactured by the above method can perform two-color display, color display, and gradation expression, and can realize a high viewing angle and high contrast.

Next, an example of this embodiment will be described.

Example 1 In this example 1, a display device was manufactured as follows.

First, polyethylene terephthalate (PE
The light-transmissive tube made of T) is partially heated at a constant cycle, and a part of the tube is heated and shrunk to form a convex portion on the inner wall surface of the tube, and then the tube is colored and charged. Filled with particles and transparent insulating liquid.

Here, as the light-transmitting tube, a tube having a circular cross section and an inner diameter of 200 μm was used, and the convex portions were arranged at a pitch of 180 μm over the entire circumference of the inner wall surface of the tube, and the inner diameter of the convex portion was 10
It was formed to have a thickness of 0 to 150 μm. Silicone oil was used as the transparent insulating liquid, and a mixture of polystyrene and carbon was used as the colored charged particles, and black particles having a particle size of about 1 μm to 2 μm were used.

Further, as a method of filling the tube with the colored charged particles and the transparent insulating liquid, as shown in FIG. 8A, the transparent insulating liquid 1 and the colored charged particles 2 are appropriately used. A method of mixing in a container 21, putting one end of the tube 3 into the liquid while stirring well, and filling while sucking from the other end was used. Then, after the filling is completed, the tube 3 is heated by heating.
Both ends were closed and sealed.

Next, ITO was used as the first electrode 8 on the light-transmissive first substrate 4 made of a PET film having a thickness of 200 μm.
Was deposited and patterned in a line (see FIG. 9A). Then, after that, a whitened PET film was formed by mixing titanium oxide fine particles as a part of the insulating layer on the first electrode 8.

Next, a dark black titanium carbide film was formed as a second electrode 7 on this insulating layer, and patterned in a line shape so as to be orthogonal to the first electrode 8 by photolithography and dry etching. The line width of the second electrode 7 at this time was set to 50 μm. Then, after this, a transparent polyimide layer was formed as the insulating layer 5 so as to cover the second electrode 7 (see FIG. 9B).

Next, the tube 3 filled with the colored charged particles 2 and the transparent insulating liquid 1 described above on the first substrate 4 having the above-described structure is attached to the second electrode 7 and the tube 3 in the longitudinal direction. They were arranged in parallel (see (c) of FIG. 9). And after this,
The second substrate 6 is arranged above the tube 3 (see (d) of FIG. 9), the first substrate 4 and the second substrate 6 are aligned,
Heat was applied to the outer peripheral portion through the outer frame to bond the first and second substrates 4 and 6.

As a result, the upper and lower parts of the tube 3 are arranged on the substrates 4, 6
To be smooth, and the tubes were placed in close contact with each other without a gap (see (e) in FIG. 9). When the tube 3 is deformed in this way, the upper and lower convex portions 3a inside the tube come closer to the deformation of the tube 3, thereby forming at least a moving space S that restricts the movement of the colored charged particles 2 ( (See (f) of FIG. 9). Finally, a voltage applying means was provided to complete the display device.

Next, display was performed using the display device thus manufactured. The applied voltage was ± 50V. Here, since the colored charged particles 2 used in Example 1 were positively charged in the silicone oil, they moved to the electrode to which a negative voltage was applied. As a result, when the electrode to which the negative voltage was applied was the first electrode 8, the black colored charged particles 2 moved onto the first electrode, so that the display surface became black.

On the other hand, when the electrode to which a negative voltage was applied was the second electrode 7, blackish particles were observed on the display surface because black particles moved to the dark black electrode. The response speed at this time was 30 msec or less.
Further, no display unevenness due to uneven distribution of the colored charged particles 2 was observed.

[Example 2] In Example 2, a display device was manufactured as follows.

First, the same colored charged particles and transparent insulating liquid as in Example 1 were filled in a tube having no convex portion inside. As a method for filling the tube with the colored charged particles and the transparent insulating liquid, after the colored charged particles 2 are evenly attached to the inner wall of the tube 3 in advance, as shown in FIG. A method was used in which one end of the tube 3 was placed in an insulating liquid and suction was applied from the other end to fill the tube. After the completion of filling, both ends of the tube were closed by heating and sealed.

Next, after forming the first electrode 8 on the first substrate (see FIG. 10A) in the same manner as in Example 1, the insulating layer 5 and the second electrode 7 are formed, and thereafter. Convex structure 9 to 30
It was formed with a pitch of 0 μm and a film thickness of 30 μm (see (b) of FIG. 10). Further, thereafter, the tube 3 in which the colored charged particles 2 and the transparent insulating liquid 1 are filled on the first substrate is arranged so that the longitudinal direction of the first electrode 8 and the tube 3 are parallel to each other (FIG. 1).
0 (see (c)).

Next, after the second substrate 6 is placed above the tube 3 (see (d) of FIG. 10), the second substrate 6 is aligned with the first substrate 4, and thereafter, the outer frame is interposed on the outer peripheral portion. First with heat
And the second substrates 4 and 6 were adhered. As a result, the upper and lower portions of the tube 3 contacted the substrates 4 and 6 and became smooth, and the tubes were arranged in close contact with each other without a gap. Further, the convex portion 3a was formed on the inner wall surface of the tube 3 on the first substrate side by the convex structure 9 of the first substrate 4 (see (e) in FIG. 10). Finally, a display device was manufactured by providing voltage applying means.

Next, display was performed in the same manner as in Example 1 using the display device thus manufactured. The applied voltage was ± 50V. Also, in the second embodiment, the response speed is 30 msec or less, and the colored charged particles 2
No uneven display was observed due to uneven distribution.

[Example 3] In Example 3, a display device was manufactured as follows.

First, polyethylene terephthalate (PE
After the convex portion 3a is formed on the inner wall surface of the tube 3 by heating one surface of the light-transmissive tube 3 made of T) at a constant cycle, the colored charged particles 2 and the transparent insulating material are formed in the tube 3. Liquid 1 was filled.

Here, as the light-transmitting tube 3, a tube having a circular cross section and an inner diameter of 200 μm is used, and the convex portion 3a has a diameter of 200.
It was formed with a μm pitch. Further, as the transparent insulating liquid 1, a dye is dissolved in silicone oil to obtain yellow (Y),
Three kinds of liquids colored in magenta (M) and cyan (C) were used, and the colored charged particles 2 were white fine particles of titanium oxide having a particle size of about 1 μm to 2 μm.

After the filling is completed, both ends of the tube 3 are closed by heating and sealed, and the tube 3 is colored in three colors.
Was produced.

Next, the first electrode 8 is formed on the first substrate by the same method as in Example 1 (see FIG. 9A), and thereafter,
A PET film was formed on the first electrode as an insulating layer.
Next, dark black titanium carbide was formed as a second electrode 7 on this insulating layer, and patterned in a line shape so as to be orthogonal to the first electrode 8 by photolithography and dry etching. The line width of the second electrode 7 at this time is 50 μm.
m. Then, after this, a transparent polyimide layer was formed as an insulating layer so as to cover the second electrode 7 (see FIG. 9B).

Next, the three colored tubes 3 are respectively attached to the second electrode 7 and the tube 3 on the thus constructed first substrate 4.
Are arranged so that their longitudinal directions are parallel ((c) of FIG. 9).
reference). Then, after this, the second substrate 6 is placed above the tube 3 (see (d) of FIG. 9), the first and second substrates 4, 6 are aligned, and heat is applied to the outer peripheral portion via an outer frame. Was added to bond the first and second substrates 4 and 6.

As a result, the upper and lower parts of the tube 3 are arranged on the substrates 4 and 6.
To be smooth, and the tubes were placed in close contact with each other without a gap (see (e) in FIG. 9). When the tube 3 is deformed in this way, the upper and lower convex portions 3a inside the tube come closer to the deformation of the tube 3, thereby forming at least a moving space S that restricts the movement of the colored charged particles 2 ( (See (f) of FIG. 9). Finally, a voltage applying means was provided to complete the display device.

Next, display was performed using the display device thus manufactured. The applied voltage was ± 50V. Here, since the colored charged particles 2 used in Example 3 were negatively charged in the silicone oil, they moved to the electrode to which a positive voltage was applied. As a result, when the electrode to which the positive voltage was applied was the first electrode 8, the white colored charged particles 2 moved to the first electrode 8 portion, so that the display surface became white display.

On the other hand, when the electrode to which a positive voltage is applied is the second electrode 7, the white colored charged particles 2 move to the second electrode 7, so that the color of the transparent insulating liquid 1 can be observed from the display surface. . The response speed at this time was 30 msec or less, and no display unevenness due to uneven distribution of colored charged particles was observed. Further, when a combination of elements in which colors of yellow (Y), cyan (C), and magenta (M) were formed was formed, color display was possible.

[Example 4] In Example 4, a display device was manufactured as follows.

First, polyethylene terephthalate (PE
A transparent tube made of T) was filled with colored charged particles and a transparent insulating liquid. Here, as the light transmissive tube, a tube having a circular cross section and an inner diameter of 200 μm was used. In addition, silicone oil is used as the transparent insulating liquid, and polysterene is mixed as the colored charged particles and yellow (Y), magenta (M), and cyan (C) colorants are mixed, and the particle size is three. Those having a size of 1 μm to 2 μm were used.

Further, as a method for filling the colored charged particles and the transparent insulating liquid into the tube 3, the above-mentioned FIG.
As shown in, a method of uniformly adhering the colored charged particles 2 of one color on the inner wall of the tube 3 in advance and then inserting one end of the tube 3 into the insulating liquid and sucking from the other end is used. I was there. Then, after the filling was completed, both ends of the tube 3 were closed and sealed by heating.

After that, press molding was performed using a jig to form a convex portion on the inner wall surface of the tube 3. The pitch of the protrusions at this time was 200 μm. Further, the same operation was performed on the particles of the other two colors. Then, in this way, the tube 3 in which the particles of the three colors were separately enclosed was produced.

Then, as shown in FIG.
A white electrode was formed as the first electrode 8 on the light-transmissive first substrate 4 made of a PET film of 00 μm and patterned in a line shape. Then, after this, a transparent polyimide layer as an insulating layer was formed on the first electrode 8.

Next, as shown in FIG. 11B, a dark black titanium carbide film is formed as a second electrode 7 on the insulating layer, and a line shape is formed by photolithography and dry etching so as to be orthogonal to the first electrode 8. Patterned. In addition,
The line width of the second electrode 7 at this time was set to 50 μm. Then, after that, a transparent polyimide layer was formed as the insulating layer 5 so as to cover the second electrode 7.

Next, as shown in (c) of FIG. 11 (FIG. 5 and FIG. 11), three colored tubes 3 are provided on the first substrate 4.
Are arranged so that the longitudinal direction of the second electrode 7 and the tube 3 are parallel to each other (only two tubes 3 are shown in the figure), and thereafter, (d) of FIG. As shown in FIG. 2, the second substrate 6 is arranged above the tube 3, the first and second substrates 4 and 6 are aligned, and heat is applied to the outer peripheral portion through the outer frame to thereby form the first and second substrates. 4 and 6 were adhered. It is to be noted that a dark black titanium carbide film is formed on the surface of the second substrate 6 facing the second electrode 7 to form a light-shielding portion, and is patterned in a line shape by photolithography and dry etching. A black light-shielding portion 16 is provided.

As a result, as shown in FIG. 11 (e), the upper and lower parts of the tube 3 were in contact with the substrates 4 and 6 to be smooth, and the tubes were arranged in close contact with each other without any gap. Finally, a voltage applying means was provided to complete the display device.

Next, display was performed using the display device thus manufactured. The applied voltage was ± 50V. Here, the colored charged particles 13, 14, 1 used in Example 4 were used.
Since No. 5 (see FIG. 5) was positively charged in silicone oil, it moved to an electrode to which a negative voltage was applied. Accordingly, when the electrode to which the negative voltage is applied is the first electrode 8, the colored and colored charged particles 13, 14, 15 are formed on the first electrode 8.
Of the colored charged particles 2 from the display surface since
I could observe the color of.

On the other hand, when the electrode to which the negative voltage is applied is the second electrode 7, the colored charged particles 2 move to the second electrode, and thus the white color of the first electrode 8 can be observed from the display surface. The response speed at this time was 30 msee or less, and no display unevenness due to uneven distribution of the colored charged particles was observed. Further, when elements formed in the colors of yellow, cyan, and magenta were combined and formed, color display was possible.

Example 5 In this example 5, a display device was manufactured as follows.

First, the same materials and methods as in Example 1 were used except that the inner diameter of the tube was 100 μm and white fine particles of titanium oxide were used as the colored charged particles. The transparent insulating liquid 1 was filled.

Next, as shown in FIG.
An ITO film was formed as the first electrode 8 on the light-transmissive first substrate 4 made of a PET film having a thickness of 00 μm and patterned in a line shape.

Next, as shown in FIG. 12B, a colored transparent polyimide layer is formed as the insulating layer 5 on the first electrode 8, and thereafter, the second transparent electrode 7 is formed on the insulating layer 5 as the second electrode 7. A film of dark black titanium carbide was formed and patterned in a line shape so as to be orthogonal to the first electrode 8 by photolithography and dry etching. The line width of the second electrode 7 at this time was set to 30 μm.

Next, as shown in FIG. 12C, after the colored layers 17 and 18 were formed above the first electrode 8, the insulating layer 5 was formed on the entire surface. After that, as shown in FIGS. 12D to 12F, a display device was manufactured by using the same method as in Example 1.

Next, display was performed using the display device thus manufactured. The applied voltage was ± 60V. Here, since the colored charged particles 2 used in Example 5 were negatively charged in the silicone oil, they moved to the electrode to which a positive voltage was applied. As a result, when the first electrode 8 was used as the electrode to which the positive voltage was applied, the white colored charged particles 2 moved onto the colored layer, so that the display surface became white.

On the other hand, when the electrode to which a positive voltage is applied is the second electrode 7, since the white colored charged color particles 2 move onto the second electrode, the colored layers 17 and 18 can be observed from the display surface. . The response speed at this time was 30 msec or less, and no uneven display due to uneven distribution of the colored charged particles 2 was observed. In addition, when a colored layer was formed by combining elements formed with respective colors of yellow, cyan and magenta, color display was possible.

Further, when the voltage was applied for 5 msec for driving, the brightness of the reflected light of each color could be reduced to about half. As described above, by selecting various voltage application times, it is possible to perform multi-step gradation expression, and a color display device capable of gradation expression can be manufactured.

[Embodiment 6] In the present embodiment 6, a tube having an inner diameter of 30 μm and a pitch of convex portions of 30 μm is used, and the line width of the second electrode is thinned to 10 μm. A display device was manufactured in the same process as in Example 1 using a material having a thickness of about 0.5 μm to 1 μm.

Then, display was performed in the same manner as in Example 1 using the display device thus manufactured. In addition,
The applied voltage was ± 50V. Here, in Example 6, the line width of the second electrode was narrowed to shorten the migration distance, so that the response speed was 5 msec or less, and high-speed response was possible. In addition, uneven display due to uneven distribution of colored charged particles was not observed.

[0123]

As described above, as in the present invention, the transparent insulating liquid and the colored charged particles are filled in the tube having the light transmitting property and the convex portion formed on the inner wall surface.
By placing the tubes filled with the transparent insulating liquid and the colored charged particles in close contact with each other between the first substrate and the second substrate, the colored charged particles can be uniformly dispersed. Display unevenness can be reduced. In addition, the manufacturing cost can be reduced because time-consuming and labor-intensive steps such as formation of partition walls on the substrate and uniform dispersion of the colored charged particles and the transparent insulating liquid in a minute area are not required.

[Brief description of drawings]

FIG. 1 is a perspective view of an electrophoretic display device which is a display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of a cross section of the electrophoretic display device.

FIG. 3 is a diagram showing an example of a method of arranging tubes that constitute the electrophoretic display device.

FIG. 4 is a cross-sectional view of the electrophoretic display device that performs color display using transparent insulating liquids of a plurality of colors.

FIG. 5 is a sectional view of the electrophoretic display device that performs color display by using colored charged particles of a plurality of colors.

FIG. 6 is a cross-sectional view of the electrophoretic display device that performs color display by forming a colored layer on the first substrate.

FIG. 7 is a diagram illustrating gradation expression of display colors in the electrophoretic display device.

FIG. 8 is a diagram showing a method of filling the above-mentioned tube with a transparent insulating liquid and colored charged particles.

FIG. 9 is a diagram showing a method of manufacturing the electrophoretic display device.

FIG. 10 is a view showing the manufacturing method of the electrophoretic display device according to Example 2 of the above-described embodiment.

FIG. 11 is a view showing the manufacturing method of the electrophoretic display device according to Example 4 of the above-described embodiment.

FIG. 12 is a view showing the method for manufacturing the electrophoretic display device according to Example 5 of the above-described embodiment.

FIG. 13 is a diagram illustrating a configuration of a conventional electrophoretic display device.

FIG. 14 is a diagram illustrating a configuration of another conventional electrophoretic display device.

[Explanation of symbols]

1,10,11,12 Transparent insulating liquid 2,13,14,15 Colored charged particles 3 tubes 3a, 3a 'convex portion 4 First substrate 5 insulating layers 6 Second substrate 7 Second electrode 8 First electrode 9 Convex structure 16 Light-shielding part 17, 18, 19 Coloring layer 21 containers 31 electrophoretic particles 32 Insulating liquid 33, 34 electrodes 35 Translucent electrode 36 Opaque electrode 37 Support plate 38 Outside light S moving space

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A 64-11237 (JP, A) JP-A 59-34518 (JP, A) JP-A 49-24695 (JP, A) JP-A 5- 61075 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G09F 9/37 311

Claims (15)

(57) [Claims] 1. A colored charged particle dispersed in a transparent insulating liquid, and a first electrode and a second electrode for applying a voltage to the colored charged particle, the voltage being applied to the first electrode and the second electrode. Is a display device that performs display by moving the colored charged particles toward the first electrode or the second electrode by a voltage applied to the transparent electrode and filling the transparent insulating liquid and the colored charged particles into a light-transmissive tube. On the other hand, convex portions that prevent the movement of the colored charged particles are regularly formed on the inner wall surface of the tube in the longitudinal direction of the tube, and the tubes are connected to each other with the first electrode and the second electrode formed thereon. A display device characterized in that it is disposed in close contact between a first substrate and a second substrate. 2. The colored charged particles are the first and second colored particles.
The first and second regions defined by the two adjacent protrusions in the tube are divided by the voltage applied to the electrodes.
2. The device moves in parallel with the substrate.
Display device described. 3. The display device according to claim 1, wherein the convex portion is formed on an inner wall surface of the tube on the side of the first substrate on which at least the first and second electrodes are formed. 4. The display device according to claim 1, wherein the tube is made of a polymer. 5. The convex portion of the tube is formed by heating and shrinking the tube before filling the transparent insulating liquid and the colored charged particles. The display device according to any one of 1. 6. The convex portion of the tube is formed by press-molding the tube before or after filling the transparent insulating liquid and the colored charged particles. The display device according to any one of 1 to 4. 7. The convex portion of the tube is filled with the transparent insulating liquid and the colored charged particles, and at least when the tube is placed in close contact with the first and second substrates. The display device according to claim 1, wherein the display device is formed by pressing the tube by a convex structure formed on one substrate. 8. The display device according to claim 1, wherein the first electrode has a light transmitting property, and a coloring layer and a light reflecting layer are laminated on the surface of the first substrate. 9. The display according to claim 8, wherein the first electrode or the colored layer and the light reflecting layer laminated on the surface of the first electrode are colored in a color different from that of the colored charged particles. apparatus. 10. A tube in which the transparent insulating liquid is colored in a color different from that of the colored charged particles, and a tube filled with the insulating liquid of the different color is regularly arranged between the first substrate and the second substrate. The display device according to claim 1, wherein the display device is arranged. 11. The display device according to claim 1, wherein the tubes filled with the colored charged particles of different colors are regularly arranged between the first substrate and the second substrate. 12. The display device according to claim 1, wherein the second electrode is colored. 13. The display device according to claim 1, wherein at least one of the first and second substrates is light transmissive. 14. The display device of claim 13, wherein the first substrate and the second substrate are polymer films. 15. A color display is performed using any one of the color of the colored charged particles, the color of the electrode, the color of the insulating liquid, the color of the colored layer, and the color of the light reflection layer. The display device according to claim 1.