JP3466959B2 - 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 It is characterized in that the tube is filled with a light-transmissive tube, and the tubes are arranged in close contact with each other between the first substrate and the second substrate on which the first electrode and the second electrode are formed. is there.

Further, according to the present invention, the colored charged particles are dispersed in the first electrode by a voltage applied to the first electrode and the second electrode.
And moving in parallel to the second substrate.

Further, the present invention is characterized in that the transparent insulating liquid and the colored charged particles in the tube are simultaneously filled in the tube.

Further, the present invention is characterized in that the transparent insulating liquid and the colored charged particles in the tube are separately filled in the tube.

In the present invention, the tube is flexible and has a circular or elliptical cross section, and when the tube is arranged between the first and second substrates, the first and second substrates are provided. When the inner diameter in the direction perpendicular to the substrate is 1, the inner diameter in the direction parallel to the substrate is 1 or more.

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

Further, the present invention is characterized in that a colored layer is formed on the first substrate.

The present invention is also characterized in that the colored layer is colored in a color different from that of the colored charged particles.

Further, the present invention is characterized in that the transparent insulating liquid filled in the tube is colored with any one of yellow, magenta and cyan.

Further, the present invention is characterized in that the tubes filled with the insulating liquids of different colors are regularly arranged between the first substrate and the second substrate.

Further, the present invention is characterized in that the colored charged particles filled in the tube are colored yellow, magenta or cyan.

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 at least one of the first substrate and the second substrate is light transmissive.

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

Further, the present invention is characterized in that the first electrode has a light transmitting property.

Further, the present invention is characterized in that 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, and the color of the colored layer. is there.

As in the present invention, a transparent insulating liquid,
The transparent electrically conductive liquid and the colored charged particles are filled with a transparent electrically conductive liquid and 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. The colored charged particles are uniformly dispersed by arranging the tubes filled with each other in close contact with each other between the first substrate on which the first electrode and the second electrode are formed and the second substrate.

[0032]

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 electrode 8 are formed. A colored layer such as the substrate 4 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. 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.

Here, the cross-sectional shape of the tube 3 is basically not particularly limited as long as it does not hinder the movement of the colored charged particles 2, and may be circular or elliptical, but it is easy for the observer to see and has little unevenness. In order to realize the above, it is desirable that the display area is large and the colored charged particles 2 move uniformly. Therefore, assuming that the inner diameter X1 of the tube 3 in the direction parallel to the substrates 4 and 6 is 1, the inner diameter Y1 in the direction perpendicular 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 sectional view of a display device for performing color display by using transparent insulating liquids of a plurality of colors. In this display device, as shown in FIG. ), Magenta (M), and cyan (C) transparent insulative liquids 10, 11, and 12 of different colors are regularly arranged. Furthermore, while the colored charged particles 2 are white and the first electrode 8 is a translucent electrode, the display is observed from the first substrate side.

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.

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. Further, the first electrode 8 is made white, or a white colored layer (not shown) is provided between the first electrode 8 and the second electrode 7, and the display is observed from the second substrate side. ing. In this case, it is desirable that the portion 16 of the second substrate corresponding to the second electrode 7 is colored white or black for light shielding.

Here, for example, the display of yellow (Y) is
Yellow (Y) colored charged particles 13 are collected on the first electrode, and magenta (M) and cyan (C) colored charged particles 1 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 that performs color display by forming a colored layer on the first substrate 4. In this display device, as shown in FIG. Yellow (Y), magenta (M), and cyan (C) colored layers 17, 18, and 19 are formed.

The formation positions of the colored layers 17, 18 and 19 are between the first electrode 8 and the first substrate 4 and the insulating layer 5 as long as they can be observed from the observer side (second substrate side). Alternatively, it may be formed on the back surface of the first substrate or the like. Further, it may be formed on the entire surface or in a part of each place.

Then, for example, as shown in FIG.
Yellow (Y), magenta (M), and cyan (C) colored layers 17, 18 and 19 are regularly formed 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, 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 different sizes are used. For example, the particles are mixed and used.

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

First, a transparent tube is filled with colored charged particles and a transparent insulating liquid. 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. A polymer such as sulfone (PES) or an inorganic material such as glass or quartz can be used, but a polymer having high flexibility is 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, or 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, known dyes and pigments such as carbon (black), for example, phthalocyanine blue, indanthrene blue, peacock blue, permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow, benzine yellow, etc. Can be widely used. The size of the particles used is usually about 0.1 μm to 50 μm.

Further, as a method of filling the tube 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 placed in a suitable container 21. , And one end of the tube 3 is put into the liquid while stirring well, and the other end is sucked and filled at the same time, or as shown in (b), the colored charged particles 2 are preliminarily attached to the inner wall of the tube 3. There is a method in which the colored charged particles 2 and the transparent insulating liquid 1 are separately filled in the tube 3 by allowing the transparent insulating liquid 1 to enter the tube 3 after being uniformly attached.

After filling the colored charged particles 2 and the transparent insulating liquid 1 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 then (b ), The insulating layer 5 is formed so as to cover the second electrode 7. 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.

Further, 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 colored charged particles 2 and the tube 3 filled with the transparent insulating liquid 1 are placed on the first substrate 4 having the insulating layer 5 formed on the surface thereof. . In the case of color display, the tubes 3 in which the colored charged particles 2 of different colors or the transparent insulating liquid 1 are enclosed are appropriately regularly arranged, for example, in the order of yellow (Y), magenta (M), and cyan (C). Deploy.

Next, as shown in (d), the second substrate 6 is placed above the tube 3 and then aligned with the first substrate 4, and then an outer frame (not shown) is provided on 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.

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.

Further, 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, examples of the present embodiment will be described.

[Example 1] In Example 1, 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. 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-transmitting 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 this, a white PET film was formed by mixing titanium oxide fine particles as the insulating layer 5 on the first electrode 8.

Next, a dark black titanium carbide film was formed as a second electrode 7 on the insulating layer 5 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. And after this, this second
A transparent polyimide layer was formed as an insulating layer so as to cover the electrode 7 (see FIG. 9B).

Next, the tube 3 in which the colored charged particles 2 and the transparent insulating liquid 1 are filled on the first substrate 4 thus constructed.
Were arranged so that the second electrode 7 and the tube 3 were parallel to each other in the longitudinal direction (see (c) of FIG. 9). Then, after that, the second transparent 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 provided 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). Finally, a voltage applying means was provided to complete the display device.

Next, display was performed using the display device thus manufactured. The display surface is on the second substrate side,
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 is applied is the second electrode 7, blackish particles can be observed from the display surface because black particles move 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 tube 3 is filled with the colored charged particles 2 and the transparent insulating liquid 1 by using the same material and method as in Example 1, and as shown in (a) and (b) of FIG. Then, the first electrode 8, the insulating layer 5, and the second electrode 7 were formed on the first substrate in the same manner as in Example 1.

Next, the colored charged particles 2 and the tube 3 filled with the transparent insulating liquid 1 were placed on the first substrate. In addition, in this Example 2, as shown in (c), the tubes 3 were arranged so that the first electrode 8 and the longitudinal direction of the tube 3 were parallel to each other. Next, as shown in (d), the second substrate 6 is arranged above the tube 3, and then the second substrate 6 is aligned with the first substrate 4. After that, heat is applied to the outer peripheral portion through the outer frame to 1 and second substrate 4, 6
Glued.

As a result, as shown in (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 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, polyether sulfone (PES)
The colored electrically-charged particles 2 and the transparent insulating liquid 1 were filled in a light-transmitting tube 3 made of. Here, as the light-transmitting tube 3, a tube having a circular cross section and an inner diameter of 200 μm was used. Also,
As the transparent insulating liquid 1, a dye is dissolved in silicone oil to obtain yellow (Y), magenta (M), cyan (C).
The colored charged particles 2
As the white fine particles of titanium oxide, those having a particle size of about 1 μm to 2 μm were used.

Further, as a method for filling the tube 3 with the colored charged particles 2 and the transparent insulating liquid 1, as shown in FIG. 8B, the colored charged particles 2 are previously formed on the inner wall of the tube 3. Was applied uniformly, and then one end of the tube 3 was put into an insulating liquid and the tube 3 was filled while being sucked from the other end. Then, after the filling was completed, both ends of the tube 3 were closed by heating and sealed to produce three colored tubes 3.

Next, a light-transmissive first electrode 8 is patterned on the light-transmissive first substrate 4 in the same manner as in Example 1 (see FIG. 9A), and thereafter insulation is performed. PET as layer 5
A film was formed on the first electrode. Next, this insulating layer 5
A dark-black titanium carbide film was formed as a second electrode 7 on and was 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 an insulating layer so as to cover the second electrode 7 (see FIG. 9B).

Next, the three colored tubes 3 are respectively provided on the first substrate 4 having the above-mentioned structure, the second electrode 7 and the tubes 3.
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 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). Finally, a voltage applying means was provided to complete the display device.

Next, display was performed using the display device thus manufactured. In the present embodiment, the first
The substrate side was used as the display surface, and 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, and 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. In addition, when elements formed in each color of yellow (Y), cyan (C), and magenta (M) were formed in combination, color display was possible.

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

First, polyethylene terephthalate (PE
Colored charged particles 2 and transparent insulating liquid 1 were filled in a light-transmitting tube 3 made of T). Here, the transparent tube 3
The cross section was circular and the inner diameter was 200 μm. Further, silicone oil is used as the transparent insulating liquid 1, and the colored charged particles 2 are particles of three colors in which polysterene and colorants of yellow (Y), magenta (M), and cyan (C) are mixed. The size of 1 μm to 2 μm was used.

Further, as a method for filling the tube 3 with the colored charged particles 2 and the transparent insulating liquid 1, as shown in FIG. 8B, the colored charged particles 2 of one color previously formed on the inner wall of the tube 3 are used. Was applied uniformly, and then one end of the tube 3 was put into an insulating liquid and the tube 3 was filled while being sucked from the other end. Then, after the filling was completed, both ends of the tube 3 were closed and sealed by heating. 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.

Next, as shown in FIG. 11A, the thickness 2
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 the insulating layer 5 was formed on the first electrode 8.

Next, as shown in FIG. 11B, a dark black titanium carbide film is formed as the second electrode 7 on the insulating layer 5.
First by photolithography and dry etching
It was patterned in a line shape so as to be orthogonal to the electrode 8. 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 an insulating layer so as to cover the second electrode 7.

Next, as shown in FIG. 11C, the tubes 3 each having three colors are provided on the first substrate 4 and the second electrode 7 is formed.
And the tube 3 were arranged so that the longitudinal directions thereof were parallel to each other. (In the figure, only two tubes 3 are shown.)
Then, after this, as shown in FIG. 11D, the light-transmissive second substrate 6 is disposed above the tube 3, the first and second substrates 4, 6 are aligned, and the outer peripheral portion The first and second substrates 4 and 6 were bonded to each other by applying heat through the outer frame. It is to be noted that a dark black titanium carbide film was formed as a light shielding portion 16 on a portion of the surface of the second substrate 6 facing the second electrode 7, and patterned by photolithography and dry etching in a line shape. The black part 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 display surface was on the second substrate side, and the applied voltage was ± 50V. Here, since the colored charged particles 13, 14 and 15 used in Example 4 were positively charged in the silicone oil, they moved to the 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 charged particles 13, 1 are formed on the first electrode 8.
Since each of 4 and 15 moved, the color of the colored charged particles 2 could be observed from the display surface.

On the other hand, when the electrode to which a negative voltage is applied is the second electrode 7, the colored charged particles 2 move onto the second electrode, so that 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 each color of yellow, cyan, and magenta were formed in combination, 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 3 was 100 μm and white fine particles of titanium oxide were used as the colored charged particles 2. 2 and transparent insulating liquid 1 were 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. Then, after this, a colored transparent polyimide layer was formed as the insulating layer 5 on the first electrode 8.

Next, as shown in FIG. 12B, a dark black titanium carbide film is formed as a second electrode 7 on the insulating layer 5 and is orthogonal to the first electrode 8 by photolithography and dry etching. So as to form a line. 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, the insulating layer 5 was formed on the entire surface.
After this, as shown in (d) to (f) of FIG.
A display device was manufactured by using the same method as in.

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. Further, when the colored layer was formed by combining the elements formed with the 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.

[Sixth Embodiment] In the sixth embodiment, the pipe 3 is used.
In the same process as in Example 1, the inner diameter of the second electrode 7 is 30 μm, the line width of the second electrode 7 is 10 μm, and the colored charged particles 2 are about 0.5 μm to 1 μm. Was produced.

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, since the line width of the second electrode 7 was narrowed to shorten the migration distance, high-speed response was possible and the migration particle response speed was 5 mse.
It could be carried out in c or less. Further, no display unevenness due to uneven distribution of the colored charged particles 2 was observed.

[0109]

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 transparent insulating liquid and the colored charged particles are filled. By disposing the tubes in close contact with each other between the first substrate and the second substrate, it is possible to uniformly disperse the colored charged particles and thereby reduce display unevenness. 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 4 First substrate 5 insulating layers 6 Second substrate 7 Second electrode 8 First electrode 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

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-11237 (JP, A) JP-A-49-96694 (JP, A) JP-A-49-24695 (JP, A) JP-A-11- 52434 (JP, A) JP-A-1-114828 (JP, A) JP-B-49-32038 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G09F 9/37 311 G09G 3/34

Claims (16)

(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. In addition, the display device is characterized in that the tubes are arranged in close contact with each other between the first substrate and the second substrate on which the first electrode and the second electrode are formed. 2. The display according to claim 1, wherein the colored charged particles are moved in parallel with the first and second substrates by a voltage applied to the first electrode and the second electrode. apparatus. 3. The display device according to claim 1, wherein the transparent insulating liquid and the colored charged particles in the tube are simultaneously filled in the tube. 4. The display device according to claim 1, wherein the transparent insulating liquid and the colored charged particles in the tube are separately filled in the tube. 5. The tube is flexible and has a circular or elliptical cross section, and is perpendicular to the first and second substrates when arranged between the first and second substrates. The display device according to claim 1, wherein the inner diameter in the direction parallel to the substrate is 1 or more when the inner diameter in the direction is 1. 6. The display device according to claim 1, wherein the tube is made of a polymer. 7. The display device according to claim 1, wherein a colored layer is formed on the first substrate. 8. The display device according to claim 7, wherein the colored layer is colored in a color different from that of the colored charged particles. 9. The display device according to claim 1, wherein the transparent insulating liquid with which the tube is filled is colored with any one of yellow, magenta, and cyan. 10. The display device according to claim 1, wherein the tubes filled with the insulating liquids of different colors are regularly arranged between the first substrate and the second substrate. 11. The display device according to claim 1, wherein the colored charged particles filled in the tube are colored yellow, magenta, or cyan. 12. 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. 13. The display device according to claim 1, wherein at least one of the first substrate and the second substrate is light transmissive. 14. The display device of claim 13, wherein the first substrate and the second substrate are polymer films. 15. The display device according to claim 1, wherein the first electrode is light transmissive. 16. The 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, and the color of the colored layer.
16. The display device according to any one of to 15.