JP3531916B2 - Manufacturing method of electrophoresis apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates a dispersion liquid containing electrophoretic particles, a method of manufacturing an electrophoretic device comprising the step of filling the electrophoresis apparatus.

[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 visual burden caused by the viewing angle of the screen, the inconvenience of characters on the screen due to the reflected light, the flicker 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. A display device invented by Lees et al. (US Pat. No. 3,612,758) is known.

FIG. 10 shows the structure of a conventional display device and its operating principle. This device is composed of a pair of electrodes 2 and 4 facing each other with an electrophoretic dispersion 8 in which a coloring dye containing charged electrophoretic particles 9 is dissolved. At least one of the pair of electrodes 2 and 4 has a translucent structure. This display device is provided with a spacer 7 for maintaining a uniform gap between the pair of substrates 1 and 3 and for dividing and dispersing the dispersion system held between the pair of substrates 1 and 3 into small sections for sealing. Has been formed.

For driving, a voltage application circuit 40 is used to apply a voltage to the electrophoretic dispersion liquid 8 through the electrodes 2 and 4, so that the charged electrophoretic particles 9 have an opposite polarity to the electric charge of the white particles. Pull up and do. The display is shown in FIG.
As shown in (b), this is performed by the color of the charged electrophoretic particles 9 and the color of the electrophoretic dispersion liquid 8 in which a coloring pigment having a color different from the hue of the electrophoretic particles 9 is dissolved. In FIG. 10A, the color of the electrophoretic dispersion liquid 9 in which the coloring dye is dissolved is visible to the observer, and in FIG.
Is visible.

In this conventional method for manufacturing an electrophoretic display device, first, a first electrode forming substrate 5 having a first electrode 2 formed on a first substrate 1 is prepared, and a spacer 7 is formed thereon. After filling the electrophoretic dispersion liquid 8 in which the coloring dye containing the charged electrophoretic particles 9 is melted, the second electrode 4 is formed on the second substrate 2.
The second electrode formation substrate 6 on which is formed is bonded, and the dispersion system sealing process is performed.

As one of the filling methods in the conventional electrophoretic display device, as shown in FIG. 11, before assembling the first electrode forming substrate 35 and the second electrode forming substrate (not shown) into the electrophoretic display device, One or the second electrode forming substrate is coated with the electrophoretic particles 36, and then the first or second electrode forming substrate coated with the electrophoretic particles 36 is assembled into the electrophoretic display device. There is a method of filling the electrophoretic dispersion liquid 37 therein (Tokutei No. 08-50).
2599).

As an embodiment of the above method, the following steps are adopted in the step of coating the charged electrophoretic particles 36 on the first or second electrode forming substrate. The first or second electrode forming substrate is attached so that the opening 30 is provided on the attachment substrate 33 having the electrode 34 and the Mylar 38, and the migration dispersion liquid 37 containing the charged electrophoretic particles 36 is provided from the opening 30. To inject. At the same time, the voltage application circuit 4
0 is used to apply a voltage between the mounting substrate 33 and the electrodes formed on the first or second electrode forming substrate to move the charged electrophoretic particles 36 toward the first or second electrode forming substrate. Then, the first or second electrode forming substrate is coated with the electrophoretic particles 36. The potential is released after sufficient coating. Thereafter, the coated first or second electrode formation substrate is manufactured by sequentially performing the manufacturing process as described above.

The embodiment of the method for filling the electrophoretic dispersion liquid 37 containing the charged electrophoretic particles 36 is as follows.
It is effective to coat the electrophoretic particles 36 on the first or second electrode forming substrate when the distance between the pair of substrates holding the electrophoretic dispersion liquid 37 containing the electrophoretic dispersion liquid is extremely narrow, and at the time of coating. It is not necessary to appropriately adjust the concentration of the charged electrophoretic particles 36 contained in the electrophoretic dispersion liquid 37 in advance.

However, in the step of coating the electrophoretic particles 36 on the first or second electrode forming substrate, the voltage applying circuit 4 is used.
0 is used to draw the electrophoretic particles 36 to the first or second electrode forming substrate by utilizing the electrophoretic phenomenon by the direct current voltage, so that the first or second electrode forming substrate exists near the electrodes. The charged electrophoretic particles 36 having the same polarity are aggregated, and the charge amount distribution of the charged electrophoretic particles 36 is not controlled.

When the charge amount distribution of the charged electrophoretic particles 36 is not controlled, the charged electrophoretic particles 36 covering the first or second electrode forming substrate are charged electrophoretic particles 3 having a large charge amount.
6 and charged electrophoretic particles 36 having a small charge amount are mixed.
In this case, when displaying on the electrophoretic display device, the driving voltage value to be applied is increased in order to cause the electrophoretic phenomenon on the charged electrophoretic particles 36 having a small charge amount. On the other hand, when the driving voltage value is lowered, the charged electrophoretic particles 36 having a small charge amount do not move sufficiently, which causes a reduction in display contrast. That is, in order to reduce the driving voltage, a method of selecting only the charged electrophoretic particles 36 having a high charge amount, and in order to increase the contrast , a method of selecting the charged electrophoretic particles 36 having a uniform charge amount. Will be requested.

The amount of the charged electrophoretic particles attached is determined by the first electrode 32 formed on the first electrode forming substrate 35 and the mounting substrate 3.
The electrode formed on the first electrode 32 and the mounting substrate 33 when a flexible substrate is used as a substrate for an electrophoretic display device because it largely depends on the gap width between the electrode 34 and the electrode 34 formed on the mounting substrate 33. Since it is difficult to uniformly maintain the gap width with respect to the first electrode forming substrate 35 within the surface of the first electrode forming substrate 35, there is a problem that the concentration distribution of the charged electrophoretic particles 36 tends to be non-uniform.

[0013]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a charging device having an appropriate charge amount distribution without considering the space between a pair of substrates and the flexibility of a substrate material. PROBLEM TO BE SOLVED : To provide a method for manufacturing an electrophoretic device which simply fills an electrophoretic dispersion liquid containing electrophoretic particles with an appropriate concentration distribution.
It is to be.

[0014]

The present invention has been made to solve the above problems, and can be solved by adopting the following method.

Although an electrophoretic display device is described among the electrophoretic devices in the following description, the manufacturing method thereof can be applied not only to the display device but also to a device to which the electrophoretic phenomenon is applied. For example, there is an electrophoretic device such as a light control device.

[0016]

[0017]

[0018]

That is, according to the present invention, electrophoretic particles containing charged electrophoretic particles are provided between a pair of substrates in which a first electrode and a second electrode capable of applying a voltage different from that of the first electrode are formed on at least one substrate. In a method of manufacturing an electrophoretic device filled with an electrophoretic dispersion liquid, an AC voltage is applied to the first electrode and the second electrode in the electrophoretic dispersion liquid containing the charged electrophoretic particles to induce an electrophoretic phenomenon. A step of moving the charged electrophoretic particles onto the first electrode or the second electrode to cover the electrode surface on the substrate, and forming the first electrode and the second electrode coated with the charged electrophoretic particles. A step of filling the electrophoretic dispersion liquid on the substrate, and a step of sealing the electrophoretic dispersion liquid between a pair of substrates in which a first electrode and a second electrode are formed on the at least one substrate. And a method for manufacturing an electrophoretic device characterized by:

Further, the step of inducing an electrophoretic phenomenon using the substrate on which the first electrode and the second electrode are formed is performed by rotating or vibrating the substrate.

Further, the step of filling the electrophoretic dispersion liquid on the substrate on which the first electrode and the second electrode coated with the electrophoretic electrophoretic particles are formed includes the step of replenishing the electrophoretic dispersion liquid. And

Further, the step of filling the electrophoretic dispersion liquid between the pair of substrates, comprising the step of applying a DC or AC voltage to the first electrode and the second electrode included in the electrode forming substrate, it The charged electrophoretic particles are moved to the first electrode or the second electrode according to.

Further, the step of sealing the dispersion liquid between said at least one of the pair of substrates on which the first electrode and the second electrode is formed on the substrate, a first electrode included in the electrode forming substrate and a The method is characterized by comprising a step of applying a direct current or an alternating voltage to the two electrodes, whereby the charged electrophoretic particles are moved onto the first electrode or the second electrode.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophoretic device used in the present invention is described below.
As an example of a method of manufacturing a device, a method of manufacturing an electrophoretic display device will be described in detail. In the present invention, the substrate on which the electrode is formed is simply referred to as an electrode-formed substrate unless otherwise specified.

FIG. 1 is a process chart showing an example of a method for manufacturing an electrophoretic display device of the present invention. Referring to FIG. 1, in the method for manufacturing an electrophoretic display device according to the present invention, a substrate including electrodes is exposed to a migration dispersion liquid containing charged electrophoretic particles while applying a voltage to the electrodes in the first step, and the electrodes are exposed on the electrodes. Coating with charged electrophoretic particles, then filling the electrophoretic dispersion liquid on the surface of the substrate coated with charged electrophoretic particles in the second step, and further in the third step 2
The method is characterized by including the steps of assembling a single substrate and sealing the electrophoretic dispersion liquid containing charged electrophoretic particles.

That is, according to the present invention, the electrode forming substrate having the first electrode and the second electrode capable of applying a voltage different from the voltage applied to the first electrode is incorporated into the electrophoretic display device. While applying a voltage to the first electrode and the second electrode formed on the substrate, the electrode forming substrate is exposed to the electrophoretic dispersion liquid containing the electrophoretic particles, and the electrode-formed substrate is coated with the electrophoretic particles contained in the electrophoretic dispersion liquid. At this time, the electrophoretic dispersion liquid is also filled. At this stage, the electrode forming substrate is filled with the electrophoretic dispersion liquid containing the charged electrophoretic particles for covering the electrode forming substrate. After that, the electrode-formed substrate is incorporated into the electrophoretic display device. Finally, the electrophoretic dispersion liquid containing charged electrophoretic particles is sealed between the pair of substrates.

Preferably, the method has a step of aligning the polarities of the charged electrophoretic particles contained in the electrophoretic dispersion liquid before the filling.

Preferably, when the electrophoretic dispersion liquid or the electrophoretic dispersion liquid containing charged electrophoretic particles is filled on the electrode-forming substrate, the electrophoretic dispersion liquid or electrophoretic dispersion liquid containing the electrophoretic particles is charged on the electrode-forming substrate. It is immersed in a container filled with a liquid, or an electrophoretic dispersion liquid containing charged electrophoretic particles or an electrophoretic dispersion liquid is sprayed on the electrode-forming substrate. More preferably, the electrode-forming substrate is dipped in the above-mentioned container, and rotation or vibration is applied when the migration dispersion liquid containing charged electrophoretic particles or the migration dispersion liquid is sprayed. Further, when the electrophoretic dispersion liquid or electrophoretic dispersion liquid containing the charged electrophoretic particles is sprayed onto the electrode-forming substrate, it is preferable to spray from multiple directions.

Preferably, a charge control agent is dispersed in the electrophoretic dispersion liquid or electrophoretic dispersion liquid containing charged electrophoretic particles. Preferably, when sealing the electrophoretic dispersion liquid containing charged electrophoretic particles between a pair of substrates, a voltage is applied to the first electrode or the second electrode or the first electrode and the second electrode formed on the electrode-forming substrate. Is applied.

Next, the present invention will be described with reference to the drawings.
2 to 9 show an embodiment of the present invention, and sequentially explain the step of filling the electrophoretic display device with the electrophoretic dispersion liquid containing charged electrophoretic particles. Further, FIG. 1 simply explains each step of FIGS. 2 to 9 by using a flowchart.

2 to 9, the electrode forming substrate described for explaining the filling method of the present invention is an electrode forming substrate having a first electrode and a second electrode on the first substrate. This is a substrate manufactured by the method disclosed in Japanese Patent Publication No. 202804. The use of the above electrode-formed substrate in the filling method of the present invention is merely an example, and an electrode-formed substrate having a configuration having a functionally equivalent function can also be used.

In the present invention, the substrate is made of PET or PE.
A substrate made of a flexible material such as S can be used.

2 and 3 correspond to the first step shown in FIG. 1, and the voltage application circuit 41 is used with the electrode forming substrate 10 exposed to the electrophoretic dispersion liquid 17 containing the electrophoretic particles 18. The first electrode 1 formed on the electrode forming substrate 10.
When different voltages are periodically applied to the second and second electrodes 14, the charged electrophoretic particles 18 contained in the electrophoretic dispersion liquid 17 move toward the first electrode 12 or the second electrode 14. If this state is maintained for a certain period, the charged electrophoretic particles 18 that have moved onto the first electrode 12 or the second electrode 14 reach a desired concentration distribution. By appropriately adjusting this period, it is possible to obtain an appropriate concentration of the electrophoretic particles 18. Further, by appropriately adjusting the applied voltage, it is possible to obtain the charged electrophoretic particles 18 having a desired charge amount distribution.

As a result, as shown in FIG. 4, the electrophoretic dispersion liquid 17 containing charged electrophoretic particles 18 having an appropriate concentration distribution and charge amount distribution is filled on the electrode forming substrate 10 having the spacers 16. At this time, a charge control agent (not shown) is added to the electrophoretic dispersion liquid 17 containing the electrophoretic particles 18.
Is preferably dispersed.

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

Using the voltage application circuit 41, the first electrode 12
When voltages having different polarities are periodically applied to the first electrode 12 and the second electrode 14, the charged electrophoretic particles 18 are transferred onto the first electrode 12 or the first electrode 12 due to an electrophoretic phenomenon, as shown in FIGS. The second electrophoretic particles 18 move to the second electrode 14 that does not overlap with the first electrode 12, or the second electrode 14 that does not overlap the first electrode 12 is covered with the electrophoretic particles 18. Usually, the magnitude of the applied voltage is about 0 to 300 V, and the frequency is 0.01 to 50 Hz. The voltage application waveform is not particularly limited.

Normally, the plurality of charged electrophoretic particles 18 present in the electrophoretic dispersion liquid 17 all have the same polarity charge, but the electrophoretic dispersion liquid 17 temporarily shows the opposite polarity charge. In the case where there are mixed particles, only the electrophoretic particles 18 having the same polarity are selected by a means such as an electrophoresis method before the electrophoretic dispersion liquid 17 containing the electrophoretic particles 18 is filled in the electrode forming substrate 10. Is preferred.

FIG. 5 corresponds to the second step shown in FIG. 1. At this stage, if the electrophoretic dispersion liquid 17 on the electrode forming substrate 10 is insufficient, or the electrophoretic dispersion liquid 17 is excessively filled. Is preferable, the first electrode 11 and the second electrode 14 are formed by using the voltage applying circuit 41 in the same manner as in FIG.
The electrophoretic dispersion liquid 17 may be gently replenished while applying an AC or DC voltage to the. At this time, it is preferable to disperse the charge control agent in the electrophoretic dispersion liquid 17.

6 and 7 correspond to the third step shown in FIG. For example, referring to FIG. 6, the second substrate 13 is bonded so as to face the electrode forming substrate 10 shown in FIG. 4, and at the same time, the excess electrophoretic dispersion liquid 17 is poured out. After that, the periphery of the first substrate 11 and the second substrate 13 and other bonding portions (not shown) are bonded. As a result, the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 is sealed in the gap formed by the first substrate 11 and the second substrate 13. Charge migration that covers the first electrode 12 or the second electrode 14 that does not overlap the first electrode 12 due to convection of the electrophoretic dispersion liquid 17 or the like until the third step is completed or during the work in the middle thereof. When the particles 18 move, a voltage application circuit 41 is used to apply an AC or DC voltage to the first electrode 12 and the second electrode 14 to prevent the charged electrophoretic particles 18 from moving. It is preferable to take measures.

In the display device manufactured here, the charged electrophoretic particles 18 are dispersed in the electrophoretic dispersion liquid 17 in parallel with the substrate surface in accordance with the potential difference between the first electrode 12 and the second electrode 14, and the first electrode 12 is used. The display is performed by moving the second electrode 14 onto the second electrode 14 which does not overlap with the upper electrode or the first electrode. For example, as shown in FIG. 8 and FIG. Is grounded, and when positive and negative voltages are applied to the first electrode 12, the electrophoretic particles 18 gather on the electrode having a relatively low charge.

At this time, when the charged electrophoretic particles 18 and the first electrode 12 are black and the second electrode 14 is white, if the charged electrophoretic particles 18 gather on the first electrode 12, white display can be performed. On the other hand, the charged electrophoretic particles 18 serve as the first electrode 12.
If they are gathered on the second electrode 14 that does not overlap with the above, black display can be performed.

[0042]

The present invention will be described in more detail below with reference to the illustrated embodiments.

Example 1 An example of a method for manufacturing an electrophoretic display device of the present invention will be described by appropriately using FIGS. 2 to 9 in accordance with the process flowchart shown in FIG. The electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 used in this example includes an electrophoretic dispersion liquid 17 (trade name: Isopar, Exxon) containing an aliphatic hydrocarbon as a main raw material and having an average particle size. A liquid in which charged electrophoretic particles 18 made of black polystyrene having a diameter of about 1 to 2 μm and a charge control agent (not shown) were dispersed was used.

In the first step shown in FIG. 1, the concentration of the charged electrophoretic particles 18 contained in the electrophoretic dispersion liquid 17 is optimal for the display of the electrophoretic display device finally produced in this embodiment. The concentration was adjusted to be lower than the concentration.

As shown in FIG. 2, the first electrode 12 and the second electrode 14 of the electrode forming substrate 10 prepared in advance are placed in a container 50 filled with the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18. Sink so that the surface where is formed faces downward,
Immediately after that, a rectangular wave of ± 60 V was applied to the first electrode 12 and the second electrode 14 at 1 Hz. The application time was 30 minutes.

The substrate has a thickness of 100 μm and a thickness of 10 μm.
A substrate made of PET having a size of cm □ was used.

In the second step shown in FIG. 1, the liquid surface of the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 filled in the container 50 is gradually lowered so that the electrophoretic dispersion particles 18 containing the electrophoretic particles 18 are charged. The electrode forming substrate 10 immersed in the dispersion liquid 17 was released from the state of being exposed to the dispersion liquid 17 for migration containing the charged electrophoretic particles 18.

After that, as shown in FIG. 5, while applying a DC voltage of +100 V to the first electrode 12 and a voltage of -100 V to the second electrode 14, the migration in which the charge control agent is dispersed in the electrode forming substrate 10 is performed. Dispersion liquid 17 was sufficiently filled.

In the third step shown in FIG. 1, +100 V is applied to the first electrode 12 and the second electrode 14 is applied, as shown in FIG.
While the DC voltage of −100 V is being applied to the electrode-forming substrate 10, the second substrate 13 is attached to the electrode-forming substrate 10 at the same time, and at the same time, the second substrate 13 is slowly pressed from above to obtain an extra electrophoretic dispersion liquid. 17 was poured out.

After that, the periphery of the electrode forming substrate 10 and the second substrate 13 and other adhering portions are adhered by heat fusion, and the electrophoretic dispersion liquid containing the charged electrophoretic particles 18 between the two substrates. 17 was sealed. The distance between these substrates is 20
μm.

When a voltage was applied to the first electrode 12 and the second electrode 14 of the electrophoretic display device manufactured according to the above-mentioned example to perform display, the display contrast was 8 when the driving voltage was ± 40V. The response speed was about 10 msec.

Example 2 An example of a method for manufacturing an electrophoretic display device of the present invention will be described by appropriately using FIGS. 2 to 9 in accordance with the process flowchart shown in FIG. The electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 used in the present embodiment has a particle size in which the electrophoretic dispersion liquid 17 (trade name: Isoper, Exxon Co.) containing an aliphatic hydrocarbon as a main raw material is used. A liquid in which black electrified electrophoretic particles 18 of about 1 to 2 μm and a charge control agent (not shown) were dispersed was used.

In the first step shown in FIG. 1, the concentration of the charged electrophoretic particles 18 contained in the electrophoretic dispersion liquid 17 is optimal for the display of the electrophoretic display device finally manufactured in this embodiment. The concentration was adjusted to be lower than the concentration.

As shown in FIG. 2, the first electrode 12 and the second electrode 14 of the electrode forming substrate 10 prepared in advance are placed in a container 50 filled with the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18. Sink so that the surface where is formed faces downward,
Immediately after that, a rectangular wave of ± 60 V was applied to the first electrode 12 and the second electrode 14 at 1 Hz. The application time was 25 minutes. While applying the voltage, the electrode forming substrate 10 was slowly vibrated in the horizontal plane in the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18.

Thereafter, as shown in FIG. 5, while the DC voltage of +100 V is applied to the first electrode 12 and the voltage of -100 V is applied to the second electrode 14, the charge control agent is dispersed in the electrode-forming substrate 10 for migration. Dispersion liquid 17 was sufficiently filled.

Then, the same process as the third and subsequent steps described in Example 1 was performed, and a voltage was applied to the first electrode 12 and the second electrode 14 of the manufactured electrophoretic display device to perform display. When the drive voltage was ± 40 V, the display contrast was 8 and the response speed was about 10 msec.

Example 3 An example of a method for manufacturing the display device of the present invention will be described by appropriately using FIGS. 2 to 9 in accordance with the process flowchart shown in FIG. The electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 used in the present embodiment has a particle size in which the electrophoretic dispersion liquid 17 (trade name: Isoper, Exxon Co.) containing an aliphatic hydrocarbon as a main raw material is used. A liquid in which black electrified electrophoretic particles 18 of about 1 to 2 μm and a charge control agent (not shown) were dispersed was used.

In the first step shown in FIG. 1, the concentration of the charged electrophoretic particles 18 contained in the electrophoretic dispersion liquid 17 is optimal for the display of the electrophoretic display device finally produced in this embodiment. The concentration was adjusted to be lower than the concentration.

As shown in FIG. 3, the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 is applied to the surface of the electrode forming substrate 10 on which the first electrode 12 and the second electrode 14 are formed, a plurality of times. The first electrode 12 and the second electrode 1 are sprayed at the same time.
A rectangular wave of ± 60 V was applied to 4 at 1 Hz. The application time was 25 minutes. The electrode-forming substrate 1 during the spraying period
0 Slowly eccentric rotation was performed around the central axis in the direction perpendicular to the plane of the central portion.

Hereinafter, when the same process as the second and subsequent steps described in Example 1 was performed and a voltage was applied to the first electrode 12 and the second electrode 14 of the manufactured electrophoretic display device to perform display, When the drive voltage was ± 40 V, the display contrast was 8 and the response speed was about 10 msec.

Example 4 An example of a method for manufacturing the electrophoretic display device of the present invention will be described by appropriately using FIGS. 2 to 9 in accordance with the process flowchart shown in FIG. The electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 used in the present embodiment has a particle size in which the electrophoretic dispersion liquid 17 (trade name: Isoper, Exxon Co.) containing an aliphatic hydrocarbon as a main raw material is used. Black charged electrophoretic particles 18 of about 1 to 2 μm and a charge control agent (not shown) were dispersed, and further electrophoretic treatment was performed as follows.

First, a mixed solution containing the above components was filled in a container (not shown), and two electrode-forming substrates having different polarities were provided above and below the container. Next, a DC voltage of ± 100 V was applied to the two electrode-forming substrates, and only the positively charged charged electrophoretic particles 19 were collected from the container. The electrified electrophoretic particles 19 and the charge control agent thus collected were dispersed in the electrophoretic dispersion liquid 17.

In the first step shown in FIG. 1, the concentration of the charged electrophoretic particles 18 contained in the electrophoretic dispersion liquid 17 produced as described above is set to the electric charge finally produced in this embodiment. The concentration was adjusted to be lower than the optimum concentration for display on the electrophoretic display device.

As shown in FIG. 2, the electrode forming substrate 10 prepared in advance is immersed in a container 50 filled with the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 with its upper surface facing downward. , Immediately after that, ± is applied to the first electrode 11 and the second electrode 12.
A square wave of 60 V was applied at 1 Hz. The application time was 10 minutes.

Thereafter, a process similar to the second and subsequent steps described in Example 1 was performed, and a voltage was applied to the first electrode 12 and the second electrode 14 of the manufactured electrophoretic display device to perform display. When the voltage was 40 V, a display contrast of 8 and a response speed of about 10 msec were obtained.

Example 5 An example of a method of manufacturing a display device of the present invention will be described by appropriately using FIGS. 2 to 9 in accordance with the process flowchart shown in FIG. In this embodiment, the case where the first and second electrodes are formed on both of the pair of substrates will be described. Therefore, the substrate farther from the observer is the first electrode formation substrate 4
5, the substrate closer to the observer is the second electrode formation substrate 46,
This will be described below.

Charged electrophoretic particles 1 used in this example
The electrophoretic dispersion liquid 17 containing 8 is a black electrophoretic electrophoretic particle having a particle size of about 1 to 2 μm in an electrophoretic dispersion liquid (trade name: Isopar, Exxon) containing an aliphatic hydrocarbon as a main raw material. A liquid in which 18 and a charge control agent (not shown) were dispersed was used.

In the first step shown in FIG. 1, the concentration of the charged electrophoretic particles 18 contained in the electrophoretic dispersion 17 is optimal for the display of the electrophoretic display device finally produced in this embodiment. The concentration was adjusted to be lower than the concentration.

As shown in FIG. 3, the electrophoretic dispersion liquid 1 containing the charged electrophoretic particles 18 on the surface of the first electrode forming substrate 45, on which the first electrode 12 and the second electrode 14 are formed, as prepared in advance.
7 was sprayed a plurality of times, and a rectangular wave of ± 30 V was simultaneously applied to the first electrode 12 and the second electrode 14 at 1 Hz. The application time was 20 minutes. During the spraying period, the first electrode forming substrate 45 was slowly eccentrically rotated about the surface in the central portion with the vertical direction as the central axis.

Second electrode formation substrate 4 prepared in advance
The same process as above was performed on the surface of No. 6 on which the first electrode 42 and the second electrode 44 were formed. The second electrode forming substrate 4
The first electrode 42 and the second electrode 44 formed in 6 are IT0
(Indium Tin Oxide).

Thereafter, as shown in FIG. 5, the first electrode forming substrate 4 is formed.
5 of the first electrode 12 + 100V, the second electrode 14 of -10
While applying a direct current voltage of 0 V, the first electrode formation substrate 4
5. The electrophoretic dispersion liquid 17 in which the charge control agent is dispersed in No. 5
Was fully filled. The same process as above was performed on the second electrode formation substrate 46.

In the third step shown in FIG. 1, as shown in FIG. 7, the first electrode forming substrate 45 and the second electrode forming substrate 46 are formed.
While applying a DC voltage of +100 V to the first electrode and a voltage of -100 V to the second electrode formed on each of the
The first electrode forming substrate 45 is opposed to the second electrode forming substrate 46 and bonded together, and at the same time, the second electrode forming substrate 46.
Was gently pressed from above, and the excess electrophoretic dispersion liquid 17 was poured out. After that, the first electrode forming substrate 4
5 and the periphery of the second electrode forming substrate 46 and other adhering portions were adhered by heat fusion to seal the electrophoretic dispersion liquid 17 containing the charged electrophoretic particles 18 between the two substrates. The distance between the substrates was 15 μm.

The first electrode 12 formed on the first electrode forming substrate 45 and the first electrode 42 of the second electrode forming substrate 46 of the electrophoretic display device manufactured according to the above embodiments are synchronized with each other, and When the second electrode 14 formed on the one electrode formation substrate 45 and the second electrode 44 of the second electrode formation substrate 46 are synchronized and voltage is applied to each to display, the drive voltage is ± 25 V. At that time, a display contrast of 8 and a response speed of about 7 msec were obtained.

[0074]

As described above in detail, the following effects can be obtained by using the method for manufacturing an electrophoretic device of the present invention. In the step of filling the electrophoretic dispersion liquid containing charged electrophoretic particles, the charged electrophoretic particles have an appropriate charge amount distribution even when the gap between the pair of substrates is very narrow or when a flexible substrate is used. It is possible to fill the electrophoretic dispersion liquid containing a with an appropriate concentration distribution. As a result, in the electrophoretic display device in which the distance between the pair of substrates is very narrow, it is possible to achieve an extremely high display contrast with a voltage value lower than the voltage value required for conventional driving.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 2 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 3 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 4 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 5 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 6 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 7 is a schematic view showing one step of a method for manufacturing an electrophoretic display device of the present invention.

FIG. 8 is a schematic view showing an example of an electrophoretic display device manufactured by the method for manufacturing an electrophoretic display device of the present invention.

FIG. 9 is a schematic view showing an example of an electrophoretic display device manufactured by the method for manufacturing an electrophoretic display device of the present invention.

FIG. 10 is a schematic view showing a conventional electrophoretic display device.

FIG. 11 is a schematic view showing an example of a method for manufacturing a conventional electrophoretic display device.

[Explanation of symbols]

1,11,31 First substrate 2, 12, 32, 42 First electrode 3,13,43 Second substrate 4,14,44 Second electrode 5,35,45 First electrode forming substrate 6,46 Second gutter formation substrate 7,16 spacer 8,17,37 Electrophoresis dispersion 9,18,36 Electrophoretic particles 10 Electrode forming substrate 30 openings 33 mounting board 34 electrodes 38 Mylar 40, 41 voltage application circuit 50 containers

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/15-1/19

Claims (5)

(57) [Claims] 1. An electrophoretic dispersion liquid containing charged electrophoretic particles between a pair of substrates on which a first electrode and a second electrode capable of applying a voltage different from that of the first electrode are formed on at least one substrate. In the method for manufacturing an electrophoretic device filled with the electrophoretic material, the electrophoretic phenomenon is induced by applying an AC voltage to the first electrode and the second electrode in the electrophoretic dispersion liquid containing the electrophoretic particles. Moving the particles onto the first electrode or onto the second electrode to coat the electrode surface on the substrate;
Filling the electrophoretic dispersion liquid on the substrate on which the first electrode and the second electrode coated with the electrophoretic electrophoretic particles are formed, and the electrophoretic dispersion liquid on the at least one substrate And a step of sealing between a pair of substrates on which electrodes are formed. 2. The step of inducing an electrophoretic phenomenon using a substrate on which the first electrode and the second electrode are formed is performed by rotating or vibrating the substrate. Method for manufacturing an electrophoretic device. 3. The step of filling the electrophoretic dispersion liquid on the substrate on which the first electrode and the second electrode coated with the electrophoretic electrophoretic particles is formed includes the step of replenishing the electrophoretic dispersion liquid. The method for manufacturing an electrophoretic device according to claim 1. 4. The step of filling the electrophoretic dispersion liquid between the pair of substrates includes the step of applying a DC or AC voltage to the first electrode and the second electrode included in the electrode-forming substrate, The method for manufacturing an electrophoretic device according to claim 1 or 3, wherein the charged electrophoretic particles are moved to the first electrode or the second electrode by means of. 5. A step of sealing the electrophoretic dispersion liquid between a pair of substrates in which a first electrode and a second electrode are formed on the at least one substrate, the first electrode and the second electrode included in the electrode forming substrate. The electrophoresis according to claim 1, further comprising applying a DC or AC voltage to the two electrodes, whereby the charged electrophoretic particles are moved onto the first electrode or the second electrode. Device manufacturing method.