JP4589690B2 - Display device - Google Patents

Description

  The present invention relates to a structure of a display device that operates when fine particles charged by electrophoresis move.

  Recently, a display device using an electrophoretic method in which charged fine particles are operated by an electric field has been developed as a display device replacing a liquid crystal display device. This display device has a structure in which fine particles moving by applying a voltage are enclosed between a pair of substrates at least one of which is transparent.

  The fine particles moving by this voltage may be encapsulated in microcapsules or not encapsulated in microcapsules. A display device encapsulated in microcapsules is described in, for example, Patent Document 1. Yes. This display device has a memory property, and a bright reflective display is obtained and has attracted attention.

  A conventional display device disclosed in Patent Document 1 will be described with reference to the drawings. FIG. 7 is a cross-sectional view of a conventional display device using microcapsules. It is composed of a first substrate 1 made of a transparent material provided with a transparent electrode 2, an image display layer 3 made of microcapsules, and a second substrate 5 provided with a pixel electrode 4. The image display layer 3 is easily contaminated by the external environment, the movement characteristics of the fine particles are affected, and the display characteristics are easily deteriorated. Therefore, a barrier layer 25 such as silicon oxide or magnesium oxide is formed, and the adhesive layer 26 The first substrate 1 and the second substrate 5 are bonded together.

  As the first substrate 1, it is desirable to use a material having a high barrier property of gas and water vapor, and it is preferable to form a barrier layer on the front surface and / or the back surface of the first substrate.

  On the other hand, in an electrophoretic display device, as the second substrate 5, an active drive substrate in which each pixel electrode is provided with a switching element such as a TFT, a multiplex drive substrate in which simple stripe electrodes are formed, It is possible to use a static driving substrate in which connection wiring is provided for each display pixel. Note that the second substrate 5 does not need to be transparent because the white color is reflected by the image display layer 3.

  As the second substrate for active drive, glass is often used, and as the second substrate for static drive, a resin film such as acrylic, polyethylene terephthalate, polyester, or polyimide is often used. The electrophoretic display device has a strong characteristic in impact resistance, and employs a flexible substrate for both the first substrate and the second substrate, and performs display even when both substrates are curved. be able to. Therefore, the application range of the display device can be widened by using the second substrate as a resin film. On the other hand, when glass is used as the second substrate, the glass can prevent gas and water vapor from entering from the back surface and protect the image display layer. However, a resin film is used as the second substrate. In this case, it is necessary to consider the barrier property of gas or water vapor, and it is preferable to form the above-described barrier layer on the front surface and / or the back surface of the second substrate 5.

  In Patent Document 2, a surface protective layer is formed on the outer side of the first substrate in order to protect the image display layer from gas or water vapor, or a plastic base such as plastic is provided on the outer side of the second substrate. An example of a display device in which materials are laminated is described.

JP 2003-270673 A JP 2004-144640 A

  Although the reliability of the electrophoretic display device using glass as the second substrate has been improved by using the technology as described above, a resin film is used as the second substrate. When it is adopted, it is necessary to consider the connection method with the drive circuit. When performing static driving, if electrodes are arranged on the entire display area of the first substrate, only pixel-shaped pixel electrodes are arranged on the image display layer side of the second substrate, and signals are supplied to the pixel electrodes. The wiring electrode for supplying the voltage cannot be disposed on the image display layer side of the second substrate. This is because if the wiring electrode is arranged on the image display layer side, a voltage is also applied to the image display layer where the wiring electrode is arranged, and display is also performed in the wiring electrode portion. Therefore, the wiring electrode that supplies a signal to the pixel electrode is preferably disposed on the back surface side of the second substrate.

  As a connection method between the pixel electrode and the wiring electrode provided on the back surface side, through-hole connection in which an opening is provided in the second substrate to connect them can be employed. Through-hole connection is an effective connection method for high-density display. First, the second substrate corresponding to the position where both the pixel electrode made of a metal thin film provided on the surface of the second substrate and the back electrode which is a wiring electrode provided on the back surface of the second substrate overlap. An opening is formed in In the opening of the second substrate, holes are formed in both the pixel electrode and the back electrode. A metal plating process is performed on the inner surface of the opening, and the pixel electrode and the wiring electrode are electrically connected through the metal plating film. However, in such a through-hole connection in which an opening is formed in the second substrate and a metal film is provided on the inner surface of the opening by metal plating, the image display layer side of the second substrate and the back surface of the second substrate Since the electrode side is opened at the opening of the second substrate, gas or water vapor enters the image display layer from the back side of the second substrate, and in a moisture resistance reliability test in which the electrode is stored under high temperature and high humidity, unevenness, etc. Display failure occurred.

  The present invention has been made to solve the above-described problems. In an electrophoretic display device, moisture resistance reliability is improved even when a resin film is used as the second substrate, and high reliability is achieved even in static driving. It is an object to provide a display device capable of displaying density.

  In order to solve the above-mentioned problem, the first means of the present invention operates by electrophoresis between a first substrate provided with a transparent electrode, a second substrate provided with a pixel electrode, and the transparent electrode and the pixel electrode. A back electrode is disposed on a surface of the second substrate opposite to the surface including the pixel electrode, and one of the pixel electrode and the back electrode is the second substrate. The pixel electrode and the back electrode are electrically connected so as to fill the opening provided in the electrode.

  In order to solve the above-mentioned problems, the second means of the present invention is characterized in that, in the first means of the present invention, the back electrode is an electrode for connecting a driving circuit for supplying a driving signal and a pixel electrode. And

  In order to solve the above-mentioned problem, the third means of the present invention is the first means of the present invention, wherein the second substrate is a resin substrate, and the pixel electrode and the back electrode are copper foil, gold, nickel or the like. Is formed by plating a resin substrate. Preferably, the resin substrate is a flexible substrate made of polyimide or liquid crystal polymer.

  In order to solve the above-mentioned problems, another means of the present invention is the first means of the present invention, in which at least two kinds of charged particles having different colors are dispersed and encapsulated in a transparent dispersion medium as the image display layer. It is a capsule.

  In order to solve the above problems, another means of the present invention is the microcapsule according to the first means of the present invention, in which at least one kind of charged particles is dispersed and encapsulated in a colored dispersion medium as the image display layer. It is a feature.

  In order to solve the above-mentioned problem, another means of the present invention is the first means of the present invention, wherein a plurality of partition walls are provided between the first substrate and the second substrate as the image display layer, and the partition walls are provided. A colored dispersion medium and at least one kind of charged particles are enclosed therein.

  In order to solve the above-mentioned problem, another means of the present invention is the first means of the present invention, wherein a plurality of partition walls are provided between the first substrate and the second substrate as the image display layer, and a dispersion medium is provided. Is used, and at least two kinds of charged particles having different colors are sealed between the partition walls.

  In the second substrate for static driving in which wiring is connected to all the pixel electrodes, wiring is printed with carbon ink on a resin film, and an insulating film provided with an opening at the position of the pixel electrode is pasted thereon. When using a single-sided substrate on which a pixel electrode is printed with carbon ink on an insulating film, a pixel electrode made of metal is provided on the surface of the resin film, and a back electrode made of metal is provided on the back surface of the resin film. In some cases, a double-sided substrate using a so-called through-hole connection is used, in which an opening is formed in the film and the back electrode using a carbon dioxide laser or a drill, and then the pixel electrode and the back electrode are connected by copper plating. is there.

  In particular, in order to perform high-density display, a double-sided substrate capable of fine wiring is often used as the second substrate, but through-holes are formed on the double-sided substrate even after plating. As a result, gas or water vapor enters the image display layer from this through-hole, and the movement characteristics of the microparticles that are electrophoresed are affected, resulting in defects such as display unevenness. In a reliability test under high temperature and high humidity Some moisture resistance reliability was insufficient.

  However, in the present invention, either the pixel electrode made of metal or the back electrode made of metal is arranged so as to fill the opening provided in the second substrate. For example, even if openings are formed in the second substrate itself, the pixel electrodes are arranged to fill them, and when the pixel electrode and the back electrode are connected, the pixel electrode is a metal thin film. In addition, the pixel electrode itself can prevent water and water vapor from entering, and good moisture resistance reliability can be obtained.

  Furthermore, a second substrate is a so-called FPC substrate that uses a resin film with good dimensional accuracy stability, such as polyimide and liquid crystal polymer, and uses a metal thin film capable of high-density wiring for the pixel electrode and the back electrode. Therefore, an electrophoretic display device capable of high-density display can be obtained even with static driving.

  The configuration and operation of the best electrophoretic display device for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of a display device of the present invention, and FIG. 2 is a plan view of a second substrate of the display device of the present invention as viewed from the first substrate side. FIG. 5 is an example of a microcapsule used for the image display layer, and FIG. 6 is a schematic diagram for explaining the operation principle.

As shown in FIG. 1, the display device of the present invention includes a first substrate 1 made of a transparent material having a transparent electrode 2, a second substrate 5 having a pixel electrode 4 made of a metal thin film, The back surface electrode 6 is provided on the back surface of the second substrate 5, and the back electrode fills the bottom of the opening (pixel portion via) 15 in the second substrate. The pixel electrode 4 and the back electrode 6 are connected by an opening (pixel part via) 15 in the second substrate.

  Furthermore, in order to protect the back electrode, a back electrode protective layer 7 is formed, and the back surface protective film 8 and the surface protective film 9 further protect the entire display unit.

  The pixel electrode 4 is connected to the back electrode 6 by an opening (pixel part via) 15 and is connected to the output electrode 13 by an IC part via 16 again. As shown in FIG. 2, the pixel electrodes 4 are rectangular or square and are independent of each other, and all the pixel electrodes 4 are connected by an output electrode 13 and a back electrode 6 (not shown). The driving IC 11 is connected to the output electrode 13 and the input electrode 14 using a protruding electrode 12 made of metal.

  The first substrate 1 is transparent and uses a polyethylene terephthalate (PET) film having a thickness of 100 μm, and the transparent electrode 2 is made of ITO having a thickness of 50 nm. As the second substrate 5, a polyimide film having a thickness of 25 μm was used, and a copper foil having a thickness of 9 μm was used for the pixel electrode 4 and the back electrode 6. The pixel electrode 4 and the back electrode 6 are plated with gold having a thickness of 0.5 μm.

  As shown in FIG. 5, the image display layer 3 is composed of microcapsules 20. The capsule shell 21 is made of methacrylic acid resin, gum arabic, or the like. Inside, white particles 23 composed of titanium oxide and black particles composed of carbon black are formed. The particles 24 are dispersed and encapsulated in a highly viscous dispersion medium 22 such as silicone oil. The capsule shell 21 has a diameter of 30 to 50 μm, and the dispersed particle diameters are both 3 to 4 μm.

  White particles 23 are positively charged, and black particles 24 are negatively charged. Therefore, as shown in FIG. 6, when a voltage is applied to the pixel electrode 4 and the transparent electrode 2, and the pixel electrode 4 becomes a negative electrode and the transparent electrode 2 becomes a positive electrode, the negatively charged black particles 24 are on the transparent electrode side. Therefore, when observed from the transparent electrode side, the portion is displayed in black.

  On the contrary, when the pixel electrode 4 is the positive electrode and the transparent electrode 2 is the negative electrode, the positively charged white particles 23 are drawn to the transparent electrode side, so that the portion is displayed in white. Also, halftone display is possible by adjusting the voltage applied to the pixel electrode 4 and the transparent electrode 2.

  Each particle is dispersed in a highly viscous dispersion medium 22 and has a so-called memory in which after the voltage is applied, the display remains without changing the position of the particle even when the voltage is cut. Therefore, it is sufficient to apply a voltage only during initial display or rewriting, and it is possible to achieve significant power saving.

  Further, the reflectance of the white particles 23 is as high as 40 to 50% with respect to the standard white plate, and the scattering characteristics are less dependent on the viewing angle, so that an electronic paper display device that is bright and easy to see like paper is obtained. be able to.

Next, so-called blind via connection in which the pixel electrode and the back electrode are connected without providing an opening in the electrode will be described with reference to FIG. First, an opening having a diameter of 50 to 100 μm is formed on the back electrode side using a polyimide film in which a copper foil having a thickness of 10 μm is formed on both sides and using a photoetching process. Then, a carbon dioxide laser or YAG laser is irradiated from the back electrode side to the opening of the back electrode 6 to form a hole in the second substrate. At this time, the output of the laser is adjusted to a level at which the polyimide film which is the material of the second substrate is melted but the copper foil which is the pixel electrode cannot be melted. It becomes possible to form a hole only in the film.

  Next, copper having a thickness of 5 to 15 μm is formed by electrolytic plating or electroless plating only on the back electrode side, and the back surface of the pixel electrode 4 and the back electrode 6 are connected to penetrate the opening in the second substrate. Not complete blind via connection. Thereafter, a photoetching process is also performed on the pixel electrode side to form the pixel electrode 4, and finally gold plating or nickel + gold plating is performed on both surfaces.

  Thereafter, the back electrode protective layer 7 is formed using a photosensitive resin, a thermosetting resin, or a polyimide film. If necessary, a surface electrode protective layer may be similarly formed around the surface IC portion.

  Next, a method for manufacturing the display device will be described. The first substrate 1 on which the image display layer 3 is applied on the transparent electrode 2 is bonded to the second substrate 5 on which the pixel electrode 4, the back electrode 6 and the back electrode protection layer 7 are formed. Then, the surface protection film 9 is bonded using a material that is transparent and does not easily transmit gas or water vapor, thereby completing an electrophoretic display device. In order to further improve the reliability, it is more preferable to attach the back surface protective film 8 to the outside of the back electrode protective layer. In addition, since the back surface protection film 8 does not need to be transparent, it is also possible to use a metal thin film such as an aluminum foil in addition to the resin film.

  In the electrophoretic display device thus formed, the pixel electrode 4 is a metal thin film having a good gas barrier property and does not have a through-hole, so that gas or water vapor entering from the outside of the second substrate 5 can be obtained. It becomes possible to suppress entry, and a display device with good moisture resistance reliability can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 2 are diagrams showing Embodiment 1 of the present invention. FIG. 1 is a cross-sectional view for explaining the components of the display device in this embodiment, and FIG. 2 is a plan view of the second substrate of the display device of this embodiment as viewed from the first substrate side. Hereinafter, the structure of the display apparatus of an Example is demonstrated using drawing.

  In the display device of this embodiment, the opening of the second substrate uses the blind via connection in which the back electrode is arranged so as to fill the opening, and the driving IC is arranged on the same side as the pixel electrode. It is characterized by that. As shown in FIG. 1, a first substrate 1 made of a transparent material having a transparent electrode 2 over the entire display area, a second substrate 5 having a pixel electrode 4 made of a metal thin film, and a microcapsule. The back electrode 6 is provided on the back surface of the second substrate 5, and the pixel electrode 4 and the back electrode 6 are connected to each other through an opening 15 (pixel portion via) in the second substrate. Further, the output electrode 13 is also connected to the back electrode 6 by the IC part via 16.

  As the first substrate 1, a PET film having a thickness of 100 μm was used, and for the transparent electrode 2, ITO having a thickness of 0.5 μm was formed by a sputtering method. The pixel electrode 4 and the back electrode 6 were formed by using a 10 μm thick copper thin film and performing nickel plating with a thickness of 3 μm and gold plating with a thickness of 0.5 μm. The second substrate 5 was a polyimide film having a thickness of 25 μm. Further, in order to protect the back electrode 6, a back electrode protective layer 7 having a thickness of 20 μm was formed by screen printing using a thermosetting solder resist.

  As described above, the image display layer 3 is composed of a microcapsule in which a transparent dispersion medium, positively charged white particles, and negatively charged black particles are enclosed.

The first substrate 1 on which the image display layer 3 is applied on the transparent electrode 2 is pressure-bonded to the second substrate 5 on which the patterning process has been completed, and further, the back surface protective film 8 and the surface protective film 9 The entire department is protected. The surface protective film 9 is a PET film having a thickness of 100 μm coated with a gas barrier layer, and the back protective film 8 is made of the same material as the surface protective film, and both are bonded using a thermosetting adhesive layer. .

  As in the prior art shown in FIG. 7, the image display layer 3 can be provided with a gas barrier layer 25 and an adhesive layer 26, and the adhesive layer 26 can be used to connect to the pixel electrode 4.

  Since the static drive that connects the pixel electrode 4 and the output electrode 13 of the driving IC 11 is used, the pixel electrode 4 is rectangular or square as shown in FIG. 2, and the transparent electrode 2 is patterned. It is not on the entire surface of the first substrate 1. In addition, the output electrode 13 and the input electrode 14 are formed on the same surface as the pixel electrode 4 on the second substrate 5, and the output electrode 13 is connected to the back electrode 6 using the IC part via 16. It is.

  Here, the second substrate 5 is provided with the back electrode 6 so as not to provide a hole in the pixel electrode 4 and to fill the opening of the second substrate by blind via connection using the manufacturing method described above. The connection is made through the opening (pixel part via) 15 in the second substrate, and at the same time, the back electrode 6 and the IC part via 16 are connected without providing a hole in the output electrode 13. From the image display layer side of the second substrate, the opening (pixel portion via) 15 and the IC portion via 16 in the second substrate are on the back side of the substrate and cannot be seen. Each position is indicated by a circle in a transparent state.

  Finally, the driving IC 11 on which the protruding electrode 12 is formed is connected to the input electrode 14 and the output electrode 13 by an anisotropic conductive film or metal hot pressing to complete the display device.

  In this display device, the through-hole penetrating the pixel electrode 4 is not opened, and the pixel electrode 4 and the back electrode 6 which are metal thin films function as a gas barrier layer. Even so, good characteristics were obtained. Note that there is a gap of 30 to 50 μm between the pixel electrodes, and the water vapor that has passed through the second substrate 5 enters. However, since this portion is a non-display portion, the influence is small.

  Further, by using the second substrate using this blind via connection, the pitch of the output electrodes 13 can be narrowed to 100 to 150 μm. As a result, the number of pixels per unit area is large, and the density is high. It has become possible to produce an electrophoretic display device for display.

  In addition, a thin, flexible film with a thickness of 25 μm is used as the second substrate, so that the display can be made thinner, lighter, and curved compared to a TFT type using a glass substrate. The device was realized.

  As described above, the first substrate including the transparent electrode, the second substrate including the pixel electrode and the back electrode, the image display layer that operates by electrophoresis, and the pixel electrode without an opening. By using the second substrate by the blind via connection that connects to the back electrode through the hole provided in the second substrate, the entry of gas or water vapor into the image display layer is suppressed, the moisture resistance reliability is good, and An electrophoretic display device capable of high-density display was obtained.

  Since this display device also uses a resin film for the second substrate, it is light, thin, and can be bent, and it has low power consumption due to the memory property that is characteristic of the microcapsule electrophoresis method, and A bright reflective display with good viewing angle characteristics was obtained.

In this embodiment, a microcapsule containing two types of black and white particles is used as the image display layer. However, a microcapsule in which at least one type of electrophoretic particles is dispersed and enclosed in a colored dispersion medium is used. Is also possible. In this embodiment, white and black fine particles are used. However, microcapsules enclosing particles of other colors can be used. For example, by using red particles and white particles, it is possible to display red characters in the white display.

  In this embodiment, a macrocapsule containing two types of black and white particles is used as the image display layer. However, a microcapsule in which at least one type of electrophoretic particle is dispersed and enclosed in a colored dispersion medium is used. Is also possible. For example, by using a microcapsule in which a blue dye is dissolved in a dispersion medium and white particles are encapsulated, a blue character display device can be obtained on a white background.

  In this example, a 25-micron polyimide film was used as the second substrate, but a material with a thickness of 9 to 50 μm can be used. It is also possible to use a liquid crystal polymer film.

  In this embodiment, microcapsules are used as the image display layer. However, a large number of partition walls are provided between the first substrate and the second substrate, and the dispersion medium colored in the partition walls is charged with at least one kind of charge. Even if the particles are enclosed, a similar display device can be obtained. Further, as an image display layer, a powder in which a large number of partition walls are provided between the first substrate and the second substrate, no dispersion medium is used, and positive and negative charged white and black fine particles are enclosed in the partition walls. It is also possible to use body flow.

  Next, the configuration of the display device according to the second embodiment of the present invention will be described. In the display device of this embodiment, the back electrode has no hole, the pixel electrode uses the blind via connection provided to fill the opening in the second substrate, and the driving IC is the same as the back electrode. The arrangement on the side is different from the configuration of the first embodiment.

  The structure of the display device in this embodiment will be described with reference to the drawings. FIG. 3 is a cross-sectional view for explaining the components of the display device according to the present embodiment. FIG. 4 is a plan view of the second substrate of the display device according to the present embodiment as viewed from the first substrate side.

  As shown in FIG. 3, the display device of this example includes a first substrate 1 made of a transparent material provided with a transparent electrode 2, a second substrate 5 provided with a pixel electrode 4 made of a metal thin film, The back surface electrode 6 is provided on the back surface of the second substrate 5, and the pixel electrode 4 and the back electrode 6 are openings in the second substrate (pixel portion vias). 15 is connected. The output electrode 13 is formed on the back electrode side and is directly connected to the back electrode 6.

  For the first substrate 1, the transparent electrode 2, and the image display layer 3, the same materials as in Example 1 were used. The second substrate was also made of the same material except for the connection method of the pixel electrode 4 and the back electrode 6 except for that.

  The pixel electrode 4 is rectangular or square as shown in FIG. The transparent electrode 2 is not patterned and is on the entire surface of the first substrate 1. Further, an output electrode 13 and an input electrode 14 are formed on the back electrode side in order to connect the driving IC 11 to the second substrate 5.

Here, the second substrate 5 was manufactured in the same manner as the manufacturing method of the blind via connection described above. However, contrary to the first embodiment, the back electrode 6 is not provided with an opening, and the pixel electrode 4 has an opening. And connected by the pixel portion via 15. Since the driving IC 11 is arranged on the back electrode side, the IC part via used in the first embodiment is not necessary, so that the perforation processing is reduced and the manufacturing cost can be reduced.

  Although the pixel electrode 4 is once provided with a hole, when the copper plating is performed so as to connect to the pixel electrode in order to connect to the back electrode 6, the opening of the second substrate is formed of the copper plating film. It becomes possible to prevent gas and water vapor from entering by filling the pixel electrode.

  Finally, the driving IC 11 on which the protruding electrode 12 is formed is connected to the input electrode 14 and the output electrode 13 by an anisotropic conductive film or metal hot pressing to complete the display device. However, unlike the first embodiment, the driving IC is connected to the back electrode side.

  Also in the display device of this embodiment, since the opening (pixel portion via) 15 in the second substrate is covered with copper plating, the pixel electrode 4 and the back electrode 6 which are metal thin films serve as gas barrier layers. In a high-temperature and high-humidity test at 90 ° C., good characteristics were obtained even after standing for 20 days. The pixel electrode 4 has a small dent having a diameter of 40 to 60 μm and a depth of about 10 μm even after copper plating. However, since the resolution of the powder particles is about 50 to 60 μm, the dent portion is also a pixel. The display color was the same as that of the electrode, and there was no display problem.

  Further, since the second substrate of this embodiment does not require copper plating on the pixel electrode side and copper plating on the back electrode side, the pitch of the back electrodes and output electrodes is smaller than that of the first embodiment. As a result, it was possible to produce an electrophoretic display device with a higher density display.

  As described above, the first substrate including the transparent electrode, the second substrate including the pixel electrode and the back electrode, the image display layer that operates by electrophoresis, and the back electrode without the holes are provided in the first substrate. By using a second substrate with a blind via connection that connects to a pixel electrode in which an opening provided in the substrate 2 is filled, the entry of gas and water vapor is suppressed, moisture resistance reliability is good, and high-density display is achieved. Thus, an electrophoretic display device was obtained.

  Since this display device uses a resin film for the second substrate in the same manner as the display device of the first embodiment, it can be light, thin and curved, and is characteristic of the microcapsule electrophoresis method. Reflective display with low power consumption due to its memory characteristics and bright and good viewing angle characteristics was obtained.

  As is clear from the above description, according to the present invention, the opening provided in the second substrate is filled with either the pixel electrode or the back electrode, and the pixel electrode and the back electrode are electrically connected. By using the blind via connection, it is possible to provide an electrophoretic display device having good moisture resistance reliability and being thin and flexible.

It is sectional drawing which shows the structure of the display apparatus in Example 1 of this invention. It is a top view of the 1st substrate in Example 1 of the present invention. It is sectional drawing which shows the structure of the display apparatus in Example 2 of this invention. It is a top view of the 1st substrate in Example 2 of the present invention. It is a schematic sectional drawing of the microcapsule used for the image display layer of this invention. It is sectional drawing for demonstrating the drive principle of this invention. It is sectional drawing which shows the structure of the display apparatus of the conventional electrophoresis system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 Transparent electrode 3 Image display layer 4 Pixel electrode 5 2nd board | substrate 6 Back electrode 7 Back electrode protective layer 8 Back surface protective film 9 Surface protective film 11 IC for drive
12 Projection electrode 13 Output electrode 14 Input electrode 15 Opening (pixel part via)
16 IC part via 20 Microcapsule 21 Capsule shell 22 Dispersion medium 23 White particles 24 Black particles 25 Barrier layer 26 Adhesive layer

Claims (8)

Comprising: a first substrate including a transparent electrode, a second substrate including a pixel electrode, and an image display layer that works by electrophoresis between the pixel electrode and the transparent electrode, the in the second substrate on the surface opposite to the surface provided with the pixel electrode, a back electrode disposed, wherein the pixel electrode is the is arranged to fill an opening provided in the second substrate, the back electrode and the pixel electrode Are electrically connected to each other.   The display device according to claim 1, wherein the back electrode is an electrode that connects a driving circuit for supplying a driving signal and the pixel electrode.    The said 2nd board | substrate is a resin substrate, The said pixel electrode and the said back electrode are formed by plating the copper foil, gold | metal | money, or nickel on the said resin board | substrate. The display device described.   The display device according to claim 3, wherein the resin substrate is a flexible substrate made of polyimide or liquid crystal polymer.   The display device according to claim 1, wherein the image display layer is a microcapsule in which charged particles having different colors are dispersed and sealed in a transparent dispersion medium.   The display device according to claim 1, wherein the image display layer is a microcapsule in which at least one kind of charged particles is dispersed and enclosed in a colored dispersion medium.   The image display layer includes a plurality of partition walls provided between a first substrate and a second substrate, and a colored dispersion medium and at least one kind of charged particles are sealed in the partition walls. The display device according to 1. As the image display layer, a large number of partition walls are provided between the first substrate and the second substrate, and no dispersion medium is used, and at least two kinds of charged particles having different colors are sealed between the partition walls. The display device according to claim 1.

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