JP2003149689A - Method for manufacturing electrophoretic display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoretic display of high productivity and displaying quality which can simply be filled with an electrophoretic dispersing liquid by proper concentration distribution. SOLUTION: A coating substrate 10 where a coating electrode 17 is formed is coated uniformly with charged migration particles 16, and is arranged opposing a displaying substrate 48. Next, the charged migration particles 16 are moved by an electrophoretic effect to coat the displaying substrate 48. After this, the coating substrate 10 arranged opposing the displaying substrate 48 is removed, and the electrophoretic dispersing liquid 15 is replenished to the displaying substrate 48. Then, an electrophoretic dispersing liquid 15 is sealed between a pair of substrates including the displaying substrate 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrophoretic device. More specifically, the present invention relates to a method for manufacturing an electrophoretic display device in which display is performed by moving electrophoretic particles between electrodes.

[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 is capable of electrically controlling the alignment of liquid crystal molecules and changing the optical characteristics of the liquid crystal, and has been actively developed and commercialized as a display device that can meet the above needs.

However, in these liquid crystal display devices, the burden on the visual sense caused by the viewing angle of the screen, the difficulty of seeing the characters on the screen due to the reflected light, the flickering of the light source, the low brightness, etc. has not been sufficiently solved. For this reason, researches on display devices with less burden on the eyes are being actively studied.

Reflective display devices are expected from the viewpoint of low power consumption and reduction of burden on the eyes. One of them is
Harold D. An electrophoretic display device (US Pat. No. 3,612,758) invented by Lees et al. Is known. In addition, Japanese Patent Laid-Open No. 9-185087 discloses an electrophoretic display device.

FIG. 19 shows the above-mentioned conventional electrophoretic display device and its operating principle. This device is composed of a pair of electrodes 22 and 24 facing each other with an electrophoretic coloring dispersion 26 in which a coloring dye containing charged electrophoretic particles 27 is dissolved.
At least one of the pair of electrodes 22 and 24 has a translucent structure. This display device includes a pair of substrates 21, 2
The gap between the substrates 3 is kept uniform, and the pair of substrates 21, 2
A partition wall 25 is formed to divide the dispersion system sandwiched between the three parts into small sections and seal them. Driven by voltage application circuit 5
0 is applied to the electrophoretic colored dispersion liquid 26 via the electrodes 22 and 24 to generate charged electrophoretic particles 27.
Is attracted to the electrode having the opposite polarity to the electric charge of the particle itself. As shown in FIGS. 19A and 19B, the display is performed by the color of the charged electrophoretic particles 27 and the color of the electrophoretic dispersion liquid 26 having a color different from the hue of the electrophoretic particles 27. (A)
The color of the electrophoretic colored dispersion liquid 26 is visible to the observer, and the color of the charged electrophoretic particles 27 is visible to the observer in (b).

Recently, an electrophoretic display device having a novel structure has been reported (JP-A-11-202804). Unlike the conventional electrophoretic display device, charged electrophoretic particles are moved horizontally with respect to the substrate for display. As shown in FIG. 20, the configuration is such that charged electrophoretic particles 16 and transparent electrophoretic dispersion liquid 15 are applied to partition wall 4.
The first display electrode 42 and the second display electrode which face each other with the first substrate 41 and the second substrate 44 interposed therebetween and move the charged electrophoretic particles 16 in the horizontal direction with respect to the substrate as indicated by an arrow. It consists of 43. The first display electrode 42 and the second display electrode 43 for driving the charged electrophoretic particles are formed by laminating on one substrate, and the display is bright or dark depending on how the electrophoretic particles spread due to the difference in the electrode area viewed from the display surface. Give out.
A feature of this method is that the display uses changes in the in-plane distribution of charged electrophoretic particles, so a transparent dispersion can be used. Therefore, it is possible to colorize relatively easily by using a color filter layer or the like. In addition, since the two electrodes are formed on the one-sided substrate, the mounting of the two electrodes and wiring becomes simple.

Since the display on the electrophoretic display device largely depends on the concentration of the charged electrophoretic particles dispersed in the dispersion liquid, in order to obtain a high quality display, the charged electrophoretic particles are uniformly dispersed over the entire display surface. Need to let. There are the following two methods for dispersing charged electrophoretic particles in a conventional electrophoretic device.

After decompressing the two substrates bonded together with a certain gap, the substrates are immersed in a dispersion liquid containing charged electrophoretic particles, and the pressure is returned to normal pressure to carry out electrophoretic migration between the gaps. An apparatus for injecting a dispersion liquid in which particles are dispersed (Japanese Patent Laid-Open No. 11-38898).

One-sided substrate 32 on which one electrode 33 is formed
Is placed in the fluid reservoir 31 in which the counter electrode 34 is formed, the suspension medium 35 in which the charged electrophoretic particles 36 are dispersed is injected, and then a constant electric field is applied to the charged electrophoretic particles 36 to the electrode of the one-sided substrate 32. Device for adhering on 33 (FIG. 20) (JP-A-8-502599).

[0010]

[Patent Document 1] Japanese Patent Application Laid-Open No. 11-3889
According to the publication No. 8, there is no problem when the gap between the substrates is large, but when the gap is made smaller, the phenomenon that the flow of the charged electrophoretic particles becomes worse with respect to the flow of the dispersion liquid appears. There is a problem that the concentration becomes high and uniform dispersion becomes difficult.

On the other hand, in the method and apparatus 30 of Japanese Patent Publication No. 8-502599, the electrophoretic particles 36 can be attached to the entire surface of the substrate 32. However, since the amount of the charged electrophoretic particles 36 attached largely depends on the gap length between the electrode 33 of the substrate 32 and the electrode 34 on the device 30 side, when the flexible substrate is used as the substrate for the electrophoretic display device, the charged electrophoretic particles 36 are charged. There is a problem that the concentration distribution of 36 becomes non-uniform. Further, in this method, the electrode 34 having the same area as the area of the substrate 32 to which the electrophoretic particles 36 are attached must be prepared on the device 30 side, which is a big problem in terms of mass productivity and manufacturing cost.

Further, at the boundary between the first display electrode 42 and the second display electrode 43 in FIG. 20, there is a structural barrier 46 consisting of a wall or a step, and a third electrode arranged above the structural barrier 46. In the electrophoretic display device shown in FIG. 22 including the control electrode 47, the structure barrier 46 becomes an obstacle in the method disclosed in JP-A-11-38898 and JP-A-8-502599. Electrophoretic particles 36
It was difficult to manufacture a display device having the above concentration distribution, and the productivity of the display device sometimes decreased.

Therefore, an object of the present invention is to provide a method for manufacturing an electrophoretic display device having high productivity and high display quality, which can be easily filled with an appropriate concentration distribution in an electrophoretic display device having any structure. Especially.

[0014]

In order to solve the above-mentioned problems, the following method is proposed in the present invention.

The present invention relates to a method for manufacturing an electrophoretic display device, which comprises at least a display electrophoretic particle, a dispersion liquid in which the electrophoretic electrophoretic particle is dispersed, a display substrate on which a display electrode is formed, and a display drive circuit. A step of uniformly coating the charged electrophoretic particles on the coating substrate on which is formed, a step of disposing the coating substrate so as to face the display substrate, and the charged electrophoretic particles on the display substrate. A step of covering, a step of removing the covering substrate arranged facing the display substrate, a step of filling the display substrate with the electrophoretic dispersion liquid, and a pair of substrates including the display substrate. And a step of sealing the electrophoretic dispersion liquid.

In the step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coated electrodes are formed, a voltage is applied to the coated electrodes in the electrophoretic dispersion liquid containing the charged electrophoretic particles. The electrophoretic effect is induced by moving the charged electrophoretic particles onto the coated electrode to coat the coated electrode surface.

The step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed is characterized in that the coating substrate having a flat surface is used.

Further, the step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed includes a step of stirring the electrophoretic dispersion liquid.

The step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed is the second coating capable of applying a voltage different from that of the first coating electrode and the first coating electrode. Using a coating substrate with electrodes formed,
A voltage is applied to the first coated electrode and the second coated electrode in the electrophoretic dispersion liquid containing the charged electrophoretic particles to induce an electrophoretic effect, and the electrophoretic effect is generated on the first coated electrode or the second coated electrode. The method is characterized by having a step of uniformly coating the charged electrophoretic particles.

The step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode may be performed with time when applying a voltage to the first coated electrode and the second coated electrode. And a step of controlling the voltage value to move the charged electrophoretic particles toward the first coated electrode or the second coated electrode.

Further, the step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode is performed with time when applying a voltage to the first coated electrode and the second coated electrode. The method is characterized by comprising the step of controlling the polarity of the voltage or its magnitude, thereby moving the charged electrophoretic particles toward the first coated electrode or the second coated electrode.

In the step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode, the total width of the first coated electrode and the second coated electrode is larger than the size of one side of the pixel. It is characterized in that a small coating substrate is used.

The step of disposing the coating substrate so as to face the display substrate includes a step of filling the migration dispersion liquid between the coating substrate and the display substrate. It is characterized by replenishing the dispersion for use.

The step of filling the electrophoretic dispersion liquid between the coating substrate and the display substrate includes the step of applying a voltage to the coating electrode formed on the coating substrate. The charged electrophoretic particles are held on the coated electrode according to.

In the step of coating the charged electrophoretic particles on the display substrate, a voltage is applied to the coating electrodes and the display electrodes to induce an electrophoretic effect, and the charged electrophoretic particles are displayed. It is characterized in that the display electrode surface is covered by moving toward the electrodes.

Further, the step of removing the covering substrate arranged opposite to the display substrate includes a step of applying a voltage to the display electrodes formed on the display substrate, whereby the display substrate is formed. It is characterized in that the charged electrophoretic particles are moved onto the electrodes.

Further, the step of filling the display substrate with the electrophoretic dispersion liquid includes the step of applying a voltage to the display electrode formed on the display substrate, whereby the display electrode is formed. It is characterized in that the charged electrophoretic particles are moved.

The step of sealing the electrophoretic dispersion liquid between a pair of substrates including the display substrate includes the step of applying a voltage to the display electrodes formed on the display substrate. Therefore, the charged electrophoretic particles are moved onto the display electrode.

According to the manufacturing method of the present invention, an electrophoretic display device, which is a dispersion liquid for migration having an appropriate concentration, can be produced on a substrate on which any structure is formed, and the electrophoretic display is performed. Since it is possible to uniformly disperse the charged electrophoretic particles in the entire display portion of the device, it is very excellent in improving the display quality. Then, it is suitable for mass-producing the display device, and the productivity is improved.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a flow chart for briefly explaining the step of filling the electrophoretic display device of the present invention with the electrophoretic dispersion liquid containing charged electrophoretic particles. 2 to 13 sequentially explain each step.
The figures are schematic and are not drawn to scale and are greatly enlarged for clarity. Further, in this embodiment, the electrophoretic display device shown in FIG. 16 is manufactured. In the description of the steps, the first substrate 41, the first display electrode 42, the second display electrode 43, the partition wall 45, the structural barrier 46 in FIG.
The portion A including the control electrode 47 is referred to as a display substrate 48, and the second substrate 44 is referred to as a sealing substrate 49. In addition, in FIG.
Although the structure in which the first drive electrode 3 and the second drive electrode 4 are arranged in a pair in one pixel is shown, in the present invention,
It is needless to say that the number of electrodes in the pixel is not particularly limited and a configuration in which a plurality of drive electrode pairs are arranged is possible.

The covering substrate 10 for explaining the present embodiment is
It is a substrate having a first coated electrode 12 and a second coated electrode 14, and the cross section of the substrate 10 for coating is shown in FIGS.
Shown in. In order to smooth the movement of the charged electrophoretic particles during coating, it is preferable to form the insulating layer 13 on the surface of the coating substrate 10 to form a flat surface without irregularities.
The planar shapes of the first covered electrode 12 and the second covered electrode 14 are not particularly limited, and any shape such as a stripe shape, a square shape, and a circular shape can be applied, and a substrate having a functionally equivalent function is used. be able to. When the plane shape is shown as the stripe shape, in the case of FIG. 2A, FIG.
The case of FIG. 2B corresponds to that of FIG. Figure 2 (b)
In the case of FIG. 3B, the first coated electrode 12 is formed on the entire surface of the substrate.
Is formed, and then the stripe-shaped second covered electrode 14 is formed with the insulating layer 13 interposed therebetween, so that the manufacturing process is simple. First coated electrode 12 and second coated electrode 14
The total width (size of L in FIG. 2) is preferably smaller than the size of one side of the pixel, and the electrophoretic display device includes the electrophoretic display device 1 in which the charged electrophoretic particles 16 are uniformly dispersed.
5 can be filled, and further, the coating substrate 10
In the step of attaching the display substrate 48 and the display substrate 48, it is not necessary to attach the display substrate 48 in consideration of the pixel position.

The first step shown in FIG. 1 will be described with reference to FIGS. 4 and 5. First, with the coating substrate 10 in contact with the electrophoretic dispersion liquid 15 containing the charged electrophoretic particles 16, the voltage application circuit 51 is used to form the first coating electrode 12 and the first coating electrode 12 formed on the coating substrate 10. A voltage that changes periodically is applied to the two-coated electrode 14. The charged electrophoretic particles 16 contained in the electrophoretic dispersion liquid 15 move toward the first coated electrode 12 or the second coated electrode 14. When this state is maintained for a certain period of time, the charged electrophoretic particles 16 are attached to the first coating electrode 1
2 or the second coated electrode 14 can be coated uniformly. By appropriately adjusting this period, it is possible to obtain an appropriate amount of the electrophoretic particles 16. Further, by appropriately setting the area ratio of the first coating electrode 12 and the second coating electrode 14 formed on the coating substrate 10, an appropriate amount of the electrophoretic particles 16 can be obtained. Further, by appropriately adjusting the applied voltage, it is possible to obtain the charged electrophoretic particles 16 having a desired charge amount distribution. As a result, as shown in FIG. 4, an electrophoretic dispersion liquid 15 containing charged electrophoretic particles 16 having an appropriate concentration distribution and charge amount distribution can be obtained on the coating substrate 10. At this time, it is preferable to disperse a charge control agent (not shown) in the electrophoretic dispersion liquid 15 containing the electrophoretic particles 16. Further, in order to make the concentration distribution of the charged electrophoretic particles in the electrophoretic dispersion liquid 15 uniform, it is preferable to coat the electrophoretic dispersion liquid 15 with stirring.

The charge control agents include positive charge control agents and negative charge control agents. As the positive charge control agent, a metal salt of naphthenic acid (cobalt, manganese, iron, etc.), zirconium octenoate, etc. can be optionally used. As the negative charge control agent, lecithin, calcium petroleum sulfinate, sodium alkylbenzene sulfonate, alkyl alanine and the like can be optionally used.

When different voltages are periodically switched and applied to the first coating electrode 12 and the second coating electrode 14 by using the voltage applying circuit 51, the electrophoretic effect is obtained as shown in FIGS. 6 (a) and 6 (b). As a result, the charged electrophoretic particles 16 move to the first coated electrode 12 or the second coated electrode 14, and the first coated electrode 12
The top or the second coating electrode 14 is coated with the electrophoretic particles 16. Usually, the magnitude of the applied voltage is 300 V or less, and the frequency is 0.01 to 50 Hz.
The voltage application waveform is not particularly limited.

Normally, the plurality of charged electrophoretic particles 16 present in the electrophoretic dispersion liquid 15 show the same polarity charge, but it is assumed that the electrophoretic dispersion liquid 15 contains charged electrophoretic particles 16 showing the opposite polarity charge. When they are mixed, it is preferable to select only the electrophoretic particles 16 having the same polarity by a method such as an electrophoretic method before filling the electrophoretic dispersion liquid 15 containing the electrophoretic particles 16 in the coating substrate 10. preferable.

The second described in FIG. 1 with reference to FIGS. 7 and 8.
The process will be described.

At this stage, when the electrophoretic dispersion liquid 15 on the coating substrate 10 is insufficient, or when the electrophoretic dispersion liquid 1 is excessive.
In the case where it is preferable to fill 5 with it, as shown in FIG. 7, while applying an AC or DC voltage to the first coated electrode 12 and the second coated electrode 14 using the voltage application circuit 51, the voltage is slowly applied. The electrophoretic dispersion liquid 15 may be replenished. The AC or DC voltage is applied because the electrophoretic particles 16 are attracted to the first coating electrode 12 and the second coating electrode 14 when the electrophoretic dispersion liquid 15 is replenished, and the electrophoretic particles 16 are applied to the coating substrate 10. This is to prevent leakage from the top. At this time, it is preferable to disperse the charge control agent in the electrophoretic dispersion liquid 15.

Then, as shown in FIG. 8, a display substrate 48 is attached so as to face the coating substrate 10. At the same time, the excess electrophoretic dispersion liquid 15 is poured out. During the second step, due to convection of the electrophoretic dispersion liquid 15 when the substrates are attached,
When the charged electrophoretic particles 16 coated on the first coated electrode 12 and the second coated electrode 14 move, an alternating current is applied to the first coated electrode 12 and the second coated electrode 14 by using the voltage application circuit 51. It is preferable to employ a means for applying a DC voltage to attract the charged electrophoretic particles 16 to the first coating electrode 12 and the second coating electrode 14 so as to prevent them from moving.

The third step shown in FIG. 1 will be described with reference to FIG.

A voltage is applied to the first covered electrode 12, the second covered electrode 14, the first display electrode 42, and the second display electrode 43 using the voltage application circuit 50. As shown in FIG. 9 (the arrow in the figure is the moving direction), the charged electrophoretic particles 16 are caused by the electrophoretic effect.
Moves from the first covered electrode 12 and the second covered electrode 14 onto the first display electrode 42 and the second display electrode 43,
2. The second display electrode 43 is covered with the charged electrophoretic particles 16.

In FIGS. 8 and 9, three first covered electrodes 12 are assigned to one pixel, but in the present invention, the number of the first covered electrodes 12 in one pixel is not particularly limited and is arbitrary. It is needless to say that it is possible to allocate the first coated electrodes 12 in the number of

The fourth step shown in FIG. 1 will be described with reference to FIG.

The covering substrate 10 is removed from the display substrate 48. When the charged electrophoretic particles 16 covering the first display electrode 42 and the second display electrode 43 move due to convection of the electrophoretic dispersion liquid 15 when the substrate is removed during the fourth step, A voltage is applied to the first display electrode 42 and the second display electrode 43 by using the voltage application circuit 50, and the charged electrophoretic particles 1 are applied to the first display electrode 42 and the second display electrode 43.
It is preferable to take means for attracting 6 to prevent movement. In FIG. 10, a voltage is applied to the second display electrode 43 so as to collect the charged electrophoretic particles 16 and attracted.

The fifth step shown in FIG. 1 will be described with reference to FIG.

Similarly to FIG. 7, the migration dispersion liquid 15 is gently filled. At this time, the voltage applying circuit 50 is used to apply a voltage to the first display electrode 42 and the second display electrode 43 to attract the charged electrophoretic particles 16 to the first display electrode 42 and the second display electrode 43. Electrophoretic particles 16
May be prevented from flowing out from the display substrate 48. It is preferable to disperse a charge control agent in the electrophoretic dispersion liquid 15.

The sixth step shown in FIG. 1 will be described with reference to FIGS.

A sealing substrate 49 is attached to face the display substrate 48 covered with the electrophoretic particles 16.
At the same time when the sealing substrate 49 is attached, the excess electrophoretic dispersion liquid 15 is poured out. After that, the periphery of the display substrate 48 and the sealing substrate 49, and other adhesive portions (not shown)
Are glued. As a result, the electrophoretic dispersion liquid 15 containing the charged electrophoretic particles 16 is sealed between the display substrate 48 and the sealing substrate 49, and the manufacture of the electrophoretic display device is completed.

During the sixth step, the first display electrode 42 is formed by convection of the electrophoretic dispersion liquid 15 when the substrates are bonded together.
When the charged electrophoretic particles 16 covering the second display electrode 43 move, a voltage is applied to the first display electrode 42 and the second display electrode 43 by using the voltage application circuit 50 to charge the electrophoretic particles. It is preferable to take measures to prevent movement of 16.

According to the above manufacturing method, the electrophoretic display device can be easily manufactured with a flexible substrate regardless of the constitution. Further, it is possible to provide an electrophoretic display device in which charged electrophoretic particles are sealed with a uniform concentration distribution and display unevenness does not occur.

In the present embodiment, the covering substrate 10 having the structure shown in FIG. 2 is used for explaining a preferable example. However, the covering substrate 10 is a substrate of a single covering electrode 17, Substrate with covered electrode 17 on all sides (Fig. 14)
And a substrate having a patterned coated electrode 17 (see FIG.
5) can also be used. However, in the coating substrate 10 shown in FIGS. 2A and 2B, the lines of electric force near the substrate surface are
16 (a) and 16 (b), the coating substrate 10 of the single coated electrode 17 shown in FIGS. 14 and 15 is shown.
Then, as shown in FIG. 17 and FIG. 18, in the vicinity of the substrate surface when the same voltage is applied, the configuration shown in FIG. (Incidentally, the direction of the arrow of the electric force line in the figure is determined by the applied voltage.) Therefore, the coating substrate 10 having two coating electrodes 17 rather than the single coating electrode 17 as shown in FIG. In this case, the charged electrophoretic particles 16 can be coated more easily.

Further, a substrate provided with three or more coating electrodes 17 capable of applying three or more different voltages can be used as the coating substrate 10, and this also allows the charged electrophoretic particles 16 to be charged in a short time. Can be coated.
However, in terms of manufacturing cost, the process of manufacturing the coating substrate 10 including the three or more electrodes is complicated, and the configuration of the voltage application circuit 51 applied to the coating electrode 17 when used is complicated. The problem occurs. Therefore,
As the coating substrate 10, it is preferable to use a substrate having two coating electrodes 17.

Further, when the covering substrate 10 is made of a transparent material, it can be used as it is as the sealing substrate 49, and the covering electrode 17 formed on the covering substrate 10 at that time. Can also be used as an electrode for display.

In the present embodiment, the manufacturing method of the present invention has been described by exemplifying the electrophoretic display device including the structural barrier 46 and the control electrode 47 shown in FIG. 21, but the electrophoretic display device to be manufactured is The present invention is not limited to this, and any one can be applied. That is, the electrophoretic display device having the conventional structure shown in FIG. 2 or the structure shown in Japanese Patent Application Laid-Open No. 11-202804 can be manufactured by using the present invention.

Further, according to the present invention, it is possible to manufacture by an assembly line work, and it is suitable for mass production of electrophoretic display devices. In the configuration shown in FIG. 23, a continuous belt-shaped coating substrate 10 is wound around a roller 53, and the belt-shaped coating substrate 10 is synchronized with the rotation of the roller 53.
To rotate. Half of the coating substrate 10 is immersed in the dispersion liquid 15 containing the charged electrophoretic particles 16 filled in the container 52. First, the portion of the coating substrate 10 immersed in the dispersion liquid 15 is coated with the electrophoretic particles 16. To do. Then, the roller 53 is rotated to expose the surface of the electrophoretic particles 16 coated from the container. At that time, the display substrate 48 is arranged so as to face the coated surface, and the charged electrophoretic particles 16 are moved to the display substrate 48. When the display substrate 48 is coated with the electrophoretic particles 16, the portion of the coating substrate 10 newly immersed in the dispersion liquid 15 is coated with the electrophoretic particles 16, and the roller 53 is rotated to electrify the particles from the container. The surface coated with the particles 16 is exposed, and the next display substrate 48 to be coated is opposed. Similarly, the charged electrophoretic particles 16 are moved to the display substrate 48. By repeating this operation one after another, it is possible to mass-produce the electrophoretic display device.

Hereinafter, the present invention will be described in more detail according to the embodiments.

(Embodiment 1) A first embodiment according to the manufacturing method of the present invention will be described. First, the coating substrate 10 was produced.
The structure of the coating substrate 10 is the same as that shown in FIG.

An Al layer was formed as the first coated electrode 12 on the entire surface of the substrate 11 made of a polyethylene terephthalate (PET) film having a thickness of 200 μm. Thickness is about 0.2
μm. Next, an insulating layer 13 made of amorphous fluororesin was formed on the entire surface to a thickness of about 0.2 μm. Subsequently, an Al film was formed thereon as the second coated electrode 14, and was patterned into stripes by photolithography and dry etching. The width of the second coated electrode was 10 μm, and the interval between the adjacent second coated electrodes was 15 μm, that is, L in FIG. 2 was 25 μm. Next, an insulating layer 13 made of amorphous fluororesin was formed on the entire surface to flatten the surface.

The substrate manufactured by the above process was used as the coating substrate 10.

By the manufacturing method of the present invention, a 5 × 5 matrix electrophoretic display device having a pixel configuration shown in FIG. 21 was produced according to the process flowchart shown in FIG. The pixel size of the display substrate 48 is 1 mm ×
1 mm, the area ratio of the first display electrode 42 and the second display electrode 43 is 20:80, the height of the partition wall 45 is 50 μm, and the structural barrier 4
The height of 6 is 25 μm.

The electrophoretic dispersion liquid 15 containing the charged electrophoretic particles 16 used in the present embodiment includes the electrophoretic dispersion liquid 15 (trade name: Isopar, Exxon) containing an aliphatic hydrocarbon as a main raw material. A liquid in which black electrified electrophoretic particles 16 having a particle size of 1 to 2 μm and a charge control agent (not shown) were dispersed was used.

First, the first step shown in FIG. 1 was performed.

The concentration of the charged electrophoretic particles 16 contained in the electrophoretic dispersion liquid 15 was adjusted to be lower than the optimum concentration for the display of the electrophoretic display device finally manufactured in this embodiment.

As shown in FIG. 4, the first coating electrode 12 and the second coating electrode 14 of the coating substrate 10 are all for migration in the container 52 filled with the migration dispersion liquid 15 containing the charged migration particles 16. Immersion in the dispersion liquid 15 was performed, and immediately after that, a voltage application circuit 51 was used to apply a ± 60 V rectangular wave at 1 Hz to the first coating electrode 12 and the second coating electrode 14. The application time was 5 minutes. Meanwhile, the electrophoretic dispersion liquid 15 was slowly stirred.

The coating substrate 10 immersed in the electrophoretic dispersion liquid 15 containing the charged electrophoretic particles 16 was taken out from the electrophoretic dispersion liquid 15. At this time, the coating substrate 10 was uniformly coated with the electrophoretic particles 16.

As shown in FIG. 7, a voltage application circuit 51 is used to apply a DC voltage of +100 V to the first coating electrode 12 and a voltage of -100 V to the second coating electrode 14, while the coating substrate 10 is coated.
The dispersion liquid 15 for migration in which the charge control agent was dispersed was sufficiently filled.

Next, the second step shown in FIG. 1 was performed.

As shown in FIG. 8, +10 is applied to the first coated electrode 12.
The display substrate 48 is made to face the coating substrate 10 while the voltage of 0 V and −100 V is applied to the second coating electrode 14.
, And at the same time, the display substrate 48 was slowly pressed from above, and the excess electrophoretic dispersion liquid 15 was poured out.

Subsequently, the third step shown in FIG. 1 was performed.

As shown in FIG. 9, a voltage application circuit 50 is used to apply +100 V to the first coated electrode 12 and the second coated electrode 14,
-100V to the first display electrode 42 and the second display electrode 43
Was applied. At this time, the charged electrophoretic particles 1 uniformly coated on the first coating electrode 12 and the second coating electrode 14
6 moved onto the first display electrode 42 and the second display electrode 43, and the first display electrode 42 and the second display electrode 43 were uniformly covered.

Then, the fourth step shown in FIG. 1 was performed.

The voltage applying circuit 50 is removed from the first covered electrode 12 and the second covered electrode 14, and the first display electrode 42 is
The coating substrate 10 was removed while applying a voltage of 100 V and -100 V to the second display electrode 43.

Subsequently, the fifth step shown in FIG. 1 was performed.

As shown in FIG. 11, +1 is applied to the first display electrode 42.
The electrophoretic dispersion liquid 15 in which the charge control agent is dispersed is sufficiently filled in the display substrate 48 while the voltage of 00 V and −100 V is applied to the second display electrode 43.

Finally, the sixth step shown in FIG. 1 was performed.

As shown in FIG. 12, a sealing substrate 49 made of a polyethylene terephthalate (PET) film is stuck to the display substrate 48 while the voltage is being applied, and at the same time, the sealing substrate 49 is slowly moved from above. It was pressed down, and the excess electrophoretic dispersion liquid 15 was poured out.

After that, the display substrate 48 and the sealing substrate 4
Adhesion was performed by heat fusion around 9 and other adhered portions, and electrophoretic dispersion liquid 15 containing charged electrophoretic particles 16 was sealed between the two substrates.

Through the above process, a flexible electrophoretic display device having a uniform concentration distribution of the charged electrophoretic particles 16 as shown in FIG. 13 was completed. When the produced electrophoretic display device was used for display, the in-plane contrast distribution was very uniform, although the gap was very small.

(Embodiment 2) A second embodiment according to the manufacturing method of the present invention will be described.

As the coating substrate 10 in this embodiment, the same substrate as that manufactured in (Embodiment 1) was used.

As the electrophoretic display device manufactured by the manufacturing method of the present invention, a 10 × 10 matrix electrophoretic display device having a pixel structure shown in FIG. 21 was manufactured as in the first embodiment. The display substrate 48 is 1
Pixel size is 120 μm × 120 μm, first display electrode 4
2 and the area ratio of the second display electrode 43 is 20:80, the partition wall 45
Has a height of 50 μm and the structural barrier 46 has a height of 25 μm.

The electrophoretic dispersion liquid 15 containing the charged electrophoretic particles 16 used in the present embodiment includes the electrophoretic dispersion liquid 15 (trade name: Isopar, Exxon) containing an aliphatic hydrocarbon as a main raw material. A liquid in which black electrified electrophoretic particles 16 having a particle size of 1 to 2 μm and a charge control agent (not shown) were dispersed was used.

First, the first step shown in FIG. 1 was performed.

The concentration of the charged electrophoretic particles 16 contained in the electrophoretic dispersion liquid 15 was adjusted to be lower than the optimal concentration for the display of the electrophoretic display device finally manufactured in this embodiment.

As shown in FIG. 5, the electrophoretic dispersion liquid 15 containing charged electrophoretic particles 16 is sprayed a plurality of times on the surface of the coating substrate 10 on which the first coating electrode 12 and the second coating electrode 14 are formed, At the same time, a ± 60 V rectangular wave was applied to the first coated electrode 12 and the second coated electrode 14 at 1 Hz. During the spraying period, the coating substrate 10 was swung at various angles in the front, rear, left and right directions. After 5 minutes, the electrophoretic particles 16 are charged on the coating substrate 10.
Was uniformly coated.

Using the coating substrate 10 on which the charged electrophoretic particles 16 are uniformly coated, a process similar to the second and subsequent steps described in (Embodiment 1) is performed, and electrophoresis as shown in FIG. 21 is performed. A display device was manufactured.

As a result, a flexible electrophoretic display device having a uniform concentration distribution of the charged electrophoretic particles 16 was completed. When displaying with the prepared electrophoretic display device,
Although the gap was very small, the in-plane contrast distribution was very uniform.

[0088]

As described above in detail, the following effects can be obtained by using the method for manufacturing an electrophoretic display device of the present invention.

In the step of filling the electrophoretic dispersion liquid containing the charged electrophoretic particles, even when the substrate has irregularities such as walls or steps as a structural barrier, the electrophoretic dispersion liquid containing the electrophoretic particles with an appropriate charge amount. Can be filled with a uniform concentration distribution. In addition, even when the gap between the pair of substrates is extremely narrow or when a flexible substrate is used, the electrophoretic display device can be easily manufactured. As a result, there is no display unevenness for all pixels,
It is possible to manufacture an electrophoretic display device capable of simple matrix driving, which can achieve extremely good display contrast. In addition, a display device that can display on a thin curved surface can be manufactured.

Further, since the present invention can be incorporated as a line work, the device can be mass-produced, the manufacturing cost can be reduced, and the productivity can be improved.

[Brief description of drawings]

FIG. 1 shows an example of a manufacturing process of a display device according to the present invention.

FIG. 2 shows an example of a coating substrate according to the present invention.

FIG. 3 shows an example of a coating substrate in the present invention.

FIG. 4 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 5 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 6 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 7 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 8 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 9 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 10 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 11 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 12 shows an example of a method of manufacturing a display device according to the present invention.

FIG. 13 shows an example of a display device manufactured by the method for manufacturing a display device according to the present invention.

FIG. 14 shows an example of a coating substrate according to the present invention.

FIG. 15 shows an example of a coating substrate according to the present invention.

FIG. 16 shows an example of a coating substrate according to the present invention.

FIG. 17 shows an example of a coating substrate according to the present invention.

FIG. 18 shows an example of a coating substrate according to the present invention.

FIG. 19 shows an example of a conventional electrophoretic display device.

FIG. 20 shows an example of a conventional electrophoretic display device.

FIG. 21 shows an example of a method for manufacturing a conventional electrophoretic display device.

FIG. 22 shows an example of a conventional electrophoretic display device.

FIG. 23 shows an example of a method of manufacturing a display device according to the present invention.

[Explanation of symbols]

10 Coating substrate 11 board 12 First coated electrode 13 Insulation layer 14 Second coated electrode 15 Dispersion liquid for migration 16 Electrophoretic particles 17 coated electrode 21 board 22 electrodes 23 board 24 electrodes 25 partitions 26 Colored dispersion for migration 27 Electrophoretic particles 30 devices 31 Liquid reservoir 32 one-sided board 33 electrodes 34 electrodes 35 Suspension medium 36 Electrophoretic particles 41 First substrate 42 first display electrode 43 Second display electrode 44 Second substrate 45 partitions 46 Structural barrier 47 control electrode 48 display substrate 49 Sealing substrate 50 voltage application circuit 51 Voltage application circuit 52 containers 53 roller

Claims (30)

[Claims] 1. A method of manufacturing an electrophoretic device comprising at least a driving substrate on which charged electrophoretic particles, a dispersion liquid in which the charged electrophoretic particles are dispersed, a drive electrode are formed, and a drive circuit are provided. Uniformly coating the charged electrophoretic particles on the substrate for application, disposing the coating substrate facing the drive substrate, and coating the electrophoretic particles on the drive substrate. A step of removing the coating substrate arranged facing the driving substrate; a step of filling the driving substrate with the migration dispersion liquid; and a migration dispersion liquid between a pair of substrates including the driving substrate. And a step of sealing the electrophoretic device. 2. The step of uniformly coating the charged electrophoretic particles on a coating substrate on which the coated electrodes are formed comprises applying a voltage to the coated electrodes in an electrophoretic dispersion liquid containing the charged electrophoretic particles. The method of manufacturing an electrophoretic device according to claim 1, wherein the electrophoretic effect is induced by moving the charged electrophoretic particles onto the coating electrode to coat the surface of the coating electrode. 3. The coating substrate on which a coating electrode is formed is uniformly coated with the charged electrophoretic particles, the coating substrate having a flat surface is used. Alternatively, the method for manufacturing the electrophoretic device according to claim 2. 4. The method according to claim 1, wherein the step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed includes a step of stirring the electrophoretic dispersion liquid. Item 4. A method for manufacturing an electrophoretic device according to any one of Items 3. 5. The step of uniformly coating the charged electrophoretic particles on a coating substrate on which a coating electrode is formed is a second coating capable of applying a voltage different from that of the first coating electrode and the first coating electrode. Using a coating substrate on which electrodes are formed, a voltage is applied to the first coating electrode and the second coating electrode in an electrophoretic dispersion liquid containing the charged electrophoretic particles to induce an electrophoretic effect, The method for manufacturing an electrophoretic device according to claim 1, further comprising a step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode. Method. 6. The step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode is performed with time when applying a voltage to the first coated electrode and the second coated electrode. 6. The electrophoresis apparatus according to claim 5, further comprising a step of controlling a voltage value to move the charged electrophoretic particles toward the first coated electrode or the second coated electrode. Production method. 7. The step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode is carried out with time when applying a voltage to the first coated electrode and the second coated electrode. 6. The method according to claim 5, further comprising the step of controlling the polarity of the voltage or the magnitude thereof, thereby moving the charged electrophoretic particles toward the first coated electrode or the second coated electrode. Item 7. A method for manufacturing an electrophoretic device according to Item 6. 8. The step of uniformly coating the charged electrophoretic particles on the first coating electrode or the second coating electrode, wherein the total width of the first coating electrode and the second coating electrode is larger than the size of one side of the pixel. 8. The method for manufacturing an electrophoretic device according to claim 5, wherein the coating substrate having a small size is used. 9. The step of disposing the coating substrate so as to face the driving substrate includes the step of filling the migration dispersion liquid between the coating substrate and the driving substrate. 9. The method for manufacturing an electrophoretic device according to claim 1, wherein the dispersion liquid is replenished. 10. The step of filling the electrophoretic dispersion liquid between the coating substrate and the driving substrate includes the step of applying a voltage to the coating electrode formed on the coating substrate, 10. The method for manufacturing an electrophoretic device according to claim 1, wherein the charged electrophoretic particles are held on the coated electrode by the method. 11. The step of coating the charged electrophoretic particles on the driving substrate comprises applying a voltage to the coating electrode and the drive electrode to induce an electrophoretic effect to drive the charged electrophoretic particles. The method for manufacturing an electrophoretic device according to claim 1, wherein the driving electrode surface is covered by moving toward the electrode. 12. The step of removing the covering substrate disposed facing the driving substrate includes a step of applying a voltage to the driving electrodes formed on the driving substrate, whereby the driving is performed. The method for manufacturing an electrophoretic device according to claim 1, wherein the charged electrophoretic particles are moved on the electrodes. 13. The step of filling the drive substrate with the electrophoretic dispersion comprises applying a voltage to the drive electrodes formed on the drive substrate, whereby the drive electrodes are formed on the drive electrodes. The method for manufacturing an electrophoretic device according to claim 1, wherein the charged electrophoretic particles are moved. 14. The step of sealing the electrophoretic dispersion liquid between a pair of substrates including the drive substrate includes a step of applying a voltage to the drive electrodes formed on the drive substrate, 14. The method for manufacturing an electrophoretic device according to claim 1, wherein the charged electrophoretic particles are moved onto the drive electrode by means of. 15. The step of sealing an electrophoretic dispersion liquid between a pair of substrates including the drive substrate, wherein the electrophoretic dispersion liquid is sealed between the coating substrate and the drive substrate. 15. The method for manufacturing an electrophoretic device according to claim 1, wherein: 16. A method of manufacturing an electrophoretic display device comprising at least a display substrate on which charged electrophoretic particles, a dispersion liquid in which the charged electrophoretic particles are dispersed, a display electrode are formed, and a display drive circuit are formed. A step of uniformly coating the charged electrophoretic particles on the coated substrate, a step of disposing the coating substrate so as to face the display substrate, and a step of coating the display substrate with the charged electrophoretic particles. A step of removing the coating substrate arranged facing the display substrate, filling the display substrate with the electrophoretic dispersion liquid, and migrating between the pair of substrates including the display substrate. And a step of sealing the dispersion liquid for use in the electrophoretic display device. 17. The step of uniformly coating the charged electrophoretic particles on a coating substrate having a coated electrode formed thereon is performed by applying a voltage to the coated electrode in an electrophoretic dispersion liquid containing the charged electrophoretic particles. 17. The method for manufacturing an electrophoretic display device according to claim 16, wherein the electrophoretic effect is induced by moving the charged electrophoretic particles onto the coated electrode to cover the coated electrode surface. 18. The coating substrate having a flat surface is used in the step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed. The method for manufacturing the electrophoretic display device according to claim 17. 19. The method according to claim 16, wherein the step of uniformly coating the charged electrophoretic particles on the coating substrate on which the coating electrode is formed includes a step of stirring the electrophoretic dispersion liquid. Item 19. A method for manufacturing an electrophoretic display device according to any one of items 18. 20. In the step of uniformly coating the charged electrophoretic particles on a coating substrate having a coating electrode formed thereon, a second coating capable of applying different voltages to the first coating electrode and the first coating electrode. Using a coating substrate on which electrodes are formed, a voltage is applied to the first coating electrode and the second coating electrode in an electrophoretic dispersion liquid containing the charged electrophoretic particles to induce an electrophoretic effect, 20. The electrophoretic display device according to claim 16, further comprising a step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode. Production method. 21. The step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode is performed with time when applying a voltage to the first coated electrode and the second coated electrode. 21. The electrophoretic display device according to claim 20, further comprising a step of controlling a voltage value to move the charged electrophoretic particles toward the first coated electrode or the second coated electrode. Manufacturing method. 22. The step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode is carried out with time when applying a voltage to the first coated electrode and the second coated electrode. 21. The method according to claim 20, further comprising the step of controlling the polarity of the voltage or the magnitude thereof, thereby moving the charged electrophoretic particles toward the first coated electrode or the second coated electrode. Item 22. A method for manufacturing an electrophoretic display device according to Item 21. 23. In the step of uniformly coating the charged electrophoretic particles on the first coated electrode or the second coated electrode, the total width of the first coated electrode and the second coated electrode is larger than the size of one side of the pixel. 23. The method for manufacturing an electrophoretic display device according to claim 20, wherein the coating substrate is small. 24. The step of disposing the coating substrate so as to face the display substrate includes the step of filling the electrophoretic dispersion liquid between the coating substrate and the display substrate. The method for manufacturing an electrophoretic display device according to any one of claims 16 to 23, further comprising replenishing the dispersion liquid for use. 25. The step of filling the electrophoretic dispersion liquid between the coating substrate and the display substrate includes the step of applying a voltage to the coating electrode formed on the coating substrate, 25. The method of manufacturing an electrophoretic display device according to claim 16, wherein the charged electrophoretic particles are held on the coated electrode by the method described above. 26. In the step of coating the charged electrophoretic particles on the display substrate, a voltage is applied to the coating electrode and the display electrode to induce an electrophoretic effect to display the charged electrophoretic particles on the display. 26. The method for manufacturing an electrophoretic display device according to claim 16, wherein the surface of the display electrode is covered by moving toward the electrode. 27. The step of removing the covering substrate arranged to face the display substrate includes the step of applying a voltage to the display electrodes formed on the display substrate, whereby the display 27. The method of manufacturing an electrophoretic display device according to claim 16, wherein the charged electrophoretic particles are moved on the electrodes. 28. The step of filling the display substrate with the electrophoretic dispersion liquid comprises the step of applying a voltage to the display electrodes formed on the display substrate, whereby the display electrodes are formed. 28. The method for manufacturing an electrophoretic display device according to claim 16, wherein the charged electrophoretic particles are moved. 29. The step of sealing the electrophoretic dispersion liquid between a pair of substrates including the display substrate includes a step of applying a voltage to the display electrodes formed on the display substrate, 29. The method of manufacturing an electrophoretic display device according to claim 16, wherein the charged electrophoretic particles are moved onto the display electrode by means of. 30. In the step of sealing the electrophoretic dispersion liquid between a pair of substrates including the display substrate, sealing the electrophoretic dispersion liquid between the coating substrate and the display substrate. 30. The method for manufacturing an electrophoretic device according to claim 16, further comprising: