CN1991557B - Electrophoretic display device - Google Patents

Abstract

The present invention provides an electrophoretic display device and electronic equipment capable of avoiding breakage of microcapsules when sticking a waterproof film and preventing display defects. The present invention is an electrophoretic display device, which uses a protective film (14) to clamp and seal between a pair of first substrates (3) and second substrates (5) that are arranged opposite to each other. Optical characteristics occur in response to electrical stimulation. The display element sealing of the microcapsule (6) of the changing display material comprises: a first electrode (2) is provided on the opposite surface side of the first substrate (3) facing the second substrate (5), and a second electrode (2) is provided on the second substrate (5). A second electrode (4) is provided on the side of the opposite surface of the substrate (5) that faces the first substrate (3), and between the outer periphery of the opposite surface side of the first substrate (3) and the first electrode (2). A liner (16) is arranged on the gap.

Description

Electrophoretic display device

technical field

The present invention relates to electrophoretic display devices and electronic equipment. the

Background technique

Conventionally, there is known an electrophoretic display device having an electrophoretic dispersion liquid including a liquid-phase dispersion medium and electrophoretic particles, and utilizing the following phenomenon: by applying an electric field, the distribution state of the electrophoretic particles changes, whereby the optical properties of the electrophoretic dispersion liquid change. The characteristics change (for example, refer to Patent Document 1). Since such an electrophoretic display device does not require a backlight, cost reduction, thickness reduction, and the like can be achieved. Moreover, it has display memory in addition to having a wide viewing angle and high contrast, so it is attracting attention as a next-generation display device. the

In addition, among such electrophoretic display devices, there is known an electrophoretic display device in which an electrophoretic dispersion liquid is enclosed in microcapsules, and the microcapsules are sandwiched between a transparent substrate having, for example, a transparent electrode serving as a common electrode, and a pixel having a transparent electrode. electrodes between the substrates. By enclosing the electrophoretic dispersion liquid in the microcapsules, it is possible to prevent the outflow of the dispersion liquid in the manufacturing process of the display device, and to reduce the precipitation and aggregation of the electrophoretic particles. the

On the other hand, the microcapsule-type electrophoretic element has a disadvantage that if moisture or the like enters the microcapsule display layer from the outside, the electrical conductivity in the display layer becomes high and the display function deteriorates. the

Therefore, as a means of improving the moisture resistance of the electrophoretic display device, it has been widely used to prevent moisture from invading into the display layer of the electrophoretic display device by attaching a waterproof film (waterproof sheet) to the outer periphery of the electrophoretic display device body. Methods. the

For example, Patent Document 1 discloses a method of adhering a back protection material by a vacuum lamination method to an electroluminescent layer in which a transparent electrode, a light-emitting layer, a dielectric layer, and a back electrode are sequentially laminated on a translucent substrate. . the

In addition, in Patent Document 2, it is disclosed that on the upper surface (light-receiving surface) of a laminated member such as a solar battery sheet (plate) and at least one surface of a resin base material having light transmission and heat resistance, A hot-melt film with a cushioning adhesive layer is hot-pressed by rolling lamination or the like. the

When adhering the waterproof film to the main body of the electrophoretic display device by vacuum lamination or rolling lamination, certain temperature and pressure are applied. the

Patent Document 1: Japanese Patent Laid-Open No. 6-203954

Patent Document 2: Japanese Patent Laid-Open No. 11-236538

However, when forming the display electrodes on the substrate, some gaps are provided between the display electrodes and the outer periphery of the substrate (peripheral edge portion) in order to secure a certain margin. Since no display electrode is formed in this gap, a step (level difference) is formed with respect to the display electrode. the

When a waterproof film is attached to the outer periphery of such an electrophoretic display device body by vacuum lamination, temperature and pressure are applied to the electrophoretic display device body, so that the gaps in the peripheral portions of the substrate bend the substrate and cause deformation. Due to this deformation of the substrate, stronger stress is concentrated in the peripheral portion of the substrate than in other regions. Therefore, there is a problem that the microcapsules disposed at the peripheral portion of the substrate are broken, and display defects occur at the peripheral portion of the display region (see FIG. 9 ). the

Contents of the invention

In consideration of the above problems, the present invention aims to provide an electrophoretic display device and electronic equipment capable of avoiding breakage of microcapsules when a waterproof film is pasted and preventing display defects. the

In order to solve the above-mentioned problems, the present invention is an electrophoretic display device, which uses a protective film to sandwich and seal a display material whose optical characteristics change in response to electrical stimulation between a pair of opposing first substrates and second substrates. The electrophoretic display device sealed with a display element of a microcapsule, comprising: a first electrode is provided on a side of a surface of the first substrate that faces the second substrate, and a surface of the second substrate is provided with A second electrode is provided on an opposing surface side of the first substrate, and a spacer is provided in a gap between an outer periphery of the first substrate on the opposing surface side and the first electrode. the

According to this structure, since the spacer is provided on the outer periphery of the first electrode, the step between the substrate surface on which the first electrode is not provided and the first electrode is relaxed by the spacer. Along with this, the gap between the microcapsules disposed on the peripheral portion between the pair of substrates and the first substrate (or the second substrate) is filled with the spacer. Therefore, when the display element is sealed with a protective film, the peripheral portion of the first substrate (or the second substrate) is supported by the gasket 2 and the microcapsule 6, and the stress on the peripheral portion of the substrate when the protective film is pressed (deep drawn) ) concentration decreases. This eliminates deformation of the peripheral edge of the substrate, prevents breakage of the microcapsules disposed on the peripheral edge of the first substrate and the second substrate, and eliminates display defects at the peripheral edge of the display region. the

In addition, in the electrophoretic display device of the present invention, it is preferable that the thickness of the spacer is set within a range of 50% to 150% of the thickness of the first electrode. the

This is because when the thickness of the spacer exceeds 150%, the peripheral portion of the first substrate is higher than the central portion of the first substrate, and the gap between the pair of substrates becomes uneven. On the other hand, if it is less than 50%, the step between the first electrode and the substrate surface becomes large, the deformation at the peripheral edge of the substrate becomes large, and stress concentrates on the edge of the substrate. the

In addition, in the electrophoretic display device of the present invention, it is preferable that the width of the spacer measured along the radial direction at the peripheral portion is set to be twice or more than the diameter of the microcapsule. In the case where the width of the liner is less than twice the diameter of the microcapsules, when the mother sheets coated with the microcapsules are cut into the required size one by one, if the cutting position is just at the microcapsule Partially, the microcapsules are broken, and the microcapsules that protect the segment electrodes cannot be played. According to the present invention, even if the microcapsules on the dummy pattern are broken, the microcapsules on the segment electrodes for display are not broken. the

In addition, in the electrophoretic display device of the present invention, preferably, the width of the spacer is set to be less than or equal to 3 mm. In the case where the width of the gasket exceeds 3mm, in the constraint that the width W4 of the non-display area is limited within 5mm (required from the size of the product), the excessive encroachment of the gasket limits the sealing width W3 to 1.5-2.0 mm within the sealing area. According to the structure of the present invention, by reducing the seal width and gasket width included in the width of the non-display area, it can be suitably used for assembling into a product that strongly requires aesthetic appearance and miniaturization. the

In addition, according to the electrophoretic display device of the present invention, preferably, the first electrode is a pixel electrode, the second electrode is a common electrode, the pixel electrode is composed of a plurality of segment electrodes arranged in a predetermined pattern, and the spacer The outer periphery of the segment electrodes arranged on the outer side among the plurality of segment electrodes is arranged. the

In this structure, the pixel electrode is a so-called segment type composed of a plurality of segment electrodes arranged in a predetermined pattern. the

According to this configuration, even when the pixel electrodes are segmented, since the spacer is provided along the outer periphery of the segment electrodes arranged outside, the steps between the pixel electrodes and the substrate surface are buried. This reduces the concentration of stress on the peripheral edge of the substrate during pressurization (deep drawing) of the protective film. Display defects at the peripheral portion of the display area can be eliminated. the

In addition, in the electrophoretic display device of the present invention, it is preferable that the spacer is made of the same material as the pixel electrode. the

According to this configuration, since the spacer and the pixel electrode are formed of the same material, material cost reduction can be achieved. Furthermore, the spacer can be formed in the same process as that of the pixel electrode, and there is no need to add an additional process for forming the spacer. the

In addition, in the electrophoretic display device of the present invention, it is preferable that the first substrate has a protruding portion protruding from the outer shape of the second substrate, a terminal portion is provided on the protruding portion, and at least An insulating film is provided on the protruding part of the terminal part, and the spacer is provided using the same material as the insulating film. the

In the present invention, the insulating film can be used as a mask so that the adhesive member used when connecting the terminal portion of the extension portion and the circuit board is not disposed on an unnecessary portion (for example, the terminal portion). the

According to this configuration, since the insulating film and the spacer provided on the extension portion are formed of the same material, material cost reduction can be achieved. Furthermore, since the spacer can be formed by the same process as that of forming the insulating film, it is not necessary to add an additional process for forming the spacer. the

In addition, in the electrophoretic display device of the present invention, it is preferable that, on the surface opposite to the facing surface of at least one of the first substrate and the second substrate, a lining with the facing surface of the first substrate is used. At least a portion of the pad is provided with reinforcing members in a coincident manner as viewed in plan. the

According to this structure, the reinforcing member is provided on the surface opposite to the facing surface of the first substrate and the second substrate at a position overlapping with the spacer provided on the facing surface, so by increasing the thickness of the peripheral portion of the substrate , increase the rigidity of the substrate. This reduces stress concentration applied to the peripheral edge of the substrate when pressing the protective film, and eliminates deformation at the peripheral edge of the substrate. the

In addition, in the electrophoretic display device of the present invention, it is preferable that the reinforcement member has at least one of a conductive member and a protective member, and the conductive member is made of the same material as the pixel electrode provided on the opposite surface side of the first substrate. In this configuration, the protective member is made of the same material as the insulating film. the

According to this configuration, since the reinforcing member is made of the same material as the pixel electrode or the insulating film provided on the opposite surface side of the first substrate, material cost reduction can be achieved. the

In addition, the reinforcing member may be formed of a single-layer conductive member or an insulating film, or may have a laminated structure composed of a double-layer conductive member or insulating film. When the reinforcing member has a laminated structure, it is preferable to form the protective member on the conductive member so as to cover it. By making the reinforcing member a two-layer structure of the conductive member and the protective member, the rigidity of the substrate can be further increased compared to a single layer. the

An electronic device according to the present invention is characterized by comprising the above-mentioned electrophoretic display device. the

According to this configuration, since an electrophoretic display device free from display defects is provided, highly reliable and high-quality electronic equipment can be provided. the

Description of drawings

FIG. 1 is a plan view showing a schematic configuration of an electrophoretic display device according to a first embodiment. the

Fig. 2(a) is a cross-sectional view along line A-A' of the electrophoretic display device shown in Fig. 1, and (b) is a cross-sectional view along line B-B'. the

FIG. 3 is a cross-sectional view showing a manufacturing process of the electrophoretic display device. the

4 is a cross-sectional view showing a schematic configuration of an electrophoretic display device according to a second embodiment. the

5 is a cross-sectional view showing a schematic configuration of an electrophoretic display device according to a third embodiment. the

Fig. 6 is a perspective view showing a schematic structure of a wristwatch. the

Fig. 7 is a perspective view showing a schematic configuration of a mobile phone. the

FIG. 8 is a perspective view showing a schematic configuration of electronic paper. the

9 is a cross-sectional view showing a schematic configuration of a conventional electrophoretic display device. the

10 is a cross-sectional view showing the dimensional relationship of the peripheral portion of the electrophoretic display device. the

Symbol Description:

1: electrophoretic display device; 2: pixel electrode (first electrode); 2a, 2b, 2c: segment electrodes (first electrode); 3: first substrate; 4: common electrode (second electrode); 5: second Substrate; 6: microcapsule; 16: dummy electrode; 18: binder; 20: display element; 22: dummy pattern; 24: copper pattern (conductive member); 26: resist film (insulating film); 28: Reinforcement part; 32: Solder resist (insulating film)

Detailed ways

Embodiment 1

Next, the present invention will be described in detail. the

FIG. 1 is a diagram showing an embodiment of an electrophoretic display device 1 of the present invention. Reference numeral 1 in FIG. 1 denotes an electrophoretic display device. Fig. 2(a) is a sectional view along the AA' line of the electrophoretic display device 1 shown in Fig. 1, and (b) is a sectional view along the BB' line of the electrophoretic display device 1 shown in Fig. 1 picture. In addition, in each drawing used in the following description, in order to make each layer, each member, etc. into the size recognizable on a drawing, the scale ratio of each layer and each member is different. In addition, in this embodiment, each substrate surface on the side where the first substrate 3 and the second substrate 5 face each other is called an inner surface, and the side opposite to the inner surface is called an outer surface. the

(Electrophoretic display device)

As shown in FIG. 1 , the electrophoretic display device 1 has a display element 20 and a waterproof sheet 14 (protective film) covering the outer periphery of the display element 20 . the

The display element 20 has: a first substrate 3 having a plurality of pixel electrodes 2 (first electrodes) arranged opposite to each other; a second substrate 5 having a common electrode (second electrode) 4; Microcapsules 6 of display materials whose optical properties change in response to electrical stimulation. the

As the first substrate 3 and the second substrate 5, especially when the electrophoretic display device 1 is a device requiring flexibility (flexibility) such as an IC card or electronic paper, a rectangular film-like or sheet-like resin substrate is used. On the other hand, when the electrophoretic display device 1 does not need to be flexible (flexible) like a general panel, a semiconductor substrate such as glass, hard resin, or even silicon is used. the

In the present embodiment, the side of the second substrate 5 serves as a display surface for the observer to view an image, and the second substrate 5 on the observer side of the electrophoretic display device 1 uses a transparent material with high light transmittance. As such a resin substrate material, for example, polyethylene terephthalate (PET), polyethersulfone (PES), polyimide (PI), and polyethylene (PE) are preferably used. In addition, the film thickness of the second substrate 5 is preferably, for example, 100 μm or more. Thus, the rigidity of the second substrate 5 can be ensured, and the microcapsules can be prevented from breaking when the waterproof sheet 14 is pasted. the

On the one hand, the first substrate 3 disposed opposite to the second substrate 5 and not serving as the display surface does not need to be transparent (high light transmittance), and polyphthalic acid can also be used in addition to the material used for the first substrate 3. Polyester such as ethylene glycol ester (PEN), polystyrene (PS), polypropylene (PP), polycarbonate (PC), polyether ether ketone (PEEK), acrylic resin or polyacrylate, and the like. the

In addition, in the present embodiment, the outer dimension of the first substrate 3 is formed larger than that of the second substrate 5 . Three sides (upper side, lower side, and right side in FIG. 1 ) of the first substrate 3 and the second substrate 5 match. The remaining side (left side in FIG. 1 ) of the first substrate 3 protrudes from one side (left side in FIG. 1 ) of the second substrate 5 . In this embodiment, the portion of the first substrate 3 protruding from the second substrate 5 is referred to as a protruding portion 3a. the

On the protruding portion 3a of the first substrate 3, as shown in FIG. Lead wires (not shown) extending from the terminal portion 8 . the

Here, the pixel electrodes 2 and the dummy electrodes 16 formed in the display region 9 of the first substrate 3 will be described in detail. the

A plurality of pixel electrodes 2 designed in a predetermined shape are formed on the display region 9 on the inner surface side of the first substrate 3 . In the present embodiment, the pixel electrode 2 is composed of seven segment electrodes 2a, 2b, and the segment electrodes 2a, 2b are formed in an elongated hexagonal shape. Seven segment electrodes 2a, 2b are arranged in a figure-of-eight shape (so-called seven segments). Here, the long direction of the segment electrodes 2 a is arranged along the short direction of the first substrate 3 , and the long direction of the segment electrodes 2 b is arranged along the long direction of the first substrate 3 . the

In this embodiment, a set of seven segment electrodes 2a and 2b is called a segment electrode group 2c. Thus, numerals from 0 to 9 can be displayed with one segment electrode group 2c. In addition, in order to represent three digits in this embodiment, three segment electrode groups 2c, 2c, and 2c are arranged, but it is not limited to three segment electrode groups 2c, 2c, and 2c. the

In the gap S between the segment electrodes 2a', 2b' arranged on the outside of the three segment electrode groups 2c, 2c, and 2c and each side (outer peripheral edge) of the first substrate 3, a dummy electrode 16 (substrate electrode 16) is formed. pad). The dummy electrodes 16 have a predetermined thickness and function as spacers that fill up the steps between the segment electrodes 2 a , 2 b and the substrate 3 . The dummy electrode 16 is provided at a distance of, for example, 50 µm from the segment electrode 2a' to ensure insulation between the dummy electrode 16 and the segment electrode 2a'. In addition, the dummy electrodes 16 are formed up to a position overlapping with each side (outer peripheral edge) of the first substrate 3, and the clearance is zero. the

Here, the dummy electrodes 16 on the protruding portion 3 a side of the first substrate 3 are formed on the display region 9 of the first substrate 3 that is located on the inner side of the left side of the opposing second substrate 5 . At this time, as shown in FIG. 1 , the dummy electrode 16 is formed apart from the conductive portion 7 for vertically conducting the first substrate 3 and the second substrate 5 . Then, the dummy electrodes 16 are formed separately from the segment electrodes 2 a , 2 b and the conductive portion 7 , and are in a voltage released state. the

Also, the dummy electrodes 16 are formed by the same steps and materials as the segment electrodes 2a and 2b formed on the inner surface side of the first substrate 3, and are made of a copper foil pattern or a conductive material such as aluminum (Al). At this time, as shown in FIG. 2 , it is preferable to set the thickness D1 of the dummy electrode 16 to 30% to 180% of the thickness D2 of the segment electrodes 2a and 2b. It is more preferably in the range of 50% to 150%. This is because when the thickness D1 of the dummy electrode 16 is too thick, the end portions of the substrate are higher than the central portion of the substrate, and the capsule gap between the substrates 3 and 5 is not uniform. On the other hand, if the thickness D1 of the dummy electrode 16 is too thin, the step between the segment electrodes 2a and 2b and the substrate surface becomes large, and stress concentration on the substrate end cannot be eliminated. the

10 is a cross-sectional view showing the dimensional relationship of the peripheral portion of the electrophoretic display device. As shown in FIG. 10, the effective width W1 of the dummy electrode (pad) 16 (dummy pattern 22 in FIG. 4 also has the same effect) measured in the radial direction (horizontal direction of the figure) at the peripheral portion 19, that is, the microcapsule 6 and The overlapping effective width W1 of the dummy electrodes 16 in planar view is preferably set to be twice or more the diameter d (approximately 25 to 30 μm) of the microcapsule 6 . The effective width W1 of the dummy electrode 16 mentioned here will be described from the viewpoint of manufacturing a plurality of sheets at a time from a mother sheet (not shown). The overlapping portion of the microcapsule 6 and the dummy electrode 16 also has an effective width W1 in the vicinity of a cut portion (not shown) of a single sheet cut into multiple pieces from the mother sheet. On the contrary, when the effective width W1 of the dummy electrode 16 is less than twice the diameter d of the microcapsule 6, when the mother sheet coated with the microcapsule 6 is cut into the desired size one by one, if the cutting Position just in time is a part of microcapsule 6, then microcapsule 6 ruptures, can't play the effect of the microcapsule of protection section electrode group 2c (Fig. 1). That is, within the range of the effective width W1 of the dummy electrode 16, at least one non-ruptured microcapsule 6 is required to maintain normal. Therefore, on the premise that the microcapsule 6 is broken during sheet processing, the effective width W1 of the dummy electrode 16 needs to be twice or more the diameter d of the microcapsule 6 . the

According to this structure, even if the first microcapsule 6a located on the dummy electrode 16 breaks, the second microcapsule 6b located on the segment electrode group 2c for display remains without breaking. the

In this way, by changing the gap G between the first substrate 3 and the second substrate 5 at the peripheral portion 19 , it is possible to eliminate the problem of display failure caused by the rupture of the microcapsule 6 . the

On the other hand, it is preferable that the maximum width W2 of the dummy electrode 16 is set to be equal to or less than 3 mm. On the other hand, when the maximum width W2 of the dummy electrode 16 exceeds 3 mm, it cannot meet the requirements in product planning. That is, from the perspective of volume ratio, appearance, etc., in the constraints of limiting the width W4 of the ugly frame-shaped non-display area within 5mm, if the dummy electrode 16 is excessively occupied, the sealing width W3 is limited to 1.5-2.0mm. In the sealed area, the reliability deteriorates significantly. According to this structure, by reducing the seal width W3 included in the width W4 of the non-display area and the maximum width W2 of the dummy electrode 16, it can be applied to, for example, applications such as watches that require aesthetic appearance and miniaturization. nature of goods. the

In addition, as shown in FIG. 1 , in the display region 9 of the first substrate 3 , the region where the segment electrodes 2 a and 2 b are not formed becomes a background region 15 that does not contribute to display. The background area 15 is composed of an outer background area located outside the segment electrodes 2a', 2b', an inner background area located in the area surrounded by the four segment electrodes 2a, 2b, and a background area located between the segment electrodes 2a, 2b . the

Furthermore, although the microcapsules are arranged on the dummy electrode 16, since the dummy electrode 16 does not function as an electrode, the area on the dummy electrode 16 also constitutes a part of the background area that does not contribute to the display. the

On the other hand, the common electrode 4 is formed on the entire inner surface side of the second substrate 5 by vapor deposition or the like. As materials for the common electrode 4, conductive oxides such as ITO (indium tin oxide), electronically conductive polymers such as polyaniline, polyvinyl alcohol resins, and NaCl dispersed in matrix resins such as polycarbonate resins are used. , LiClO4, KCl and other ionic substances ion conductive polymers. the

Microcapsules 6 are arranged between the first substrate 3 and the second substrate 5 configured in this way, especially on the above-mentioned pixel electrodes 2 . The display material is encapsulated in the microcapsules 6 as described above, and all of them are formed to have substantially the same diameter, and in this embodiment, they are formed to have a diameter of about 30 μm. The enclosed display material has optical characteristics that change in response to electrical stimulation, specifically, electrophoretic particles, liquid crystals, etc. are the main materials. the

As a material mainly composed of electrophoretic particles, an electrophoretic dispersion liquid including electrophoretic particles and a liquid-phase dispersion medium in which the electrophoretic particles are dispersed is used. the

As the liquid dispersion medium, alcohol solvents such as water, methanol, ethanol, isopropanol, butanol, octanol, and methyl cellosolve, various esters such as ethyl acetate and butyl acetate, acetone, etc., can be used. , methyl ethyl ketone, methyl isobutyl ketone and other ketones, pentane, hexane, octane and other aliphatic hydrocarbons, cyclohexane and methyl cyclohexane and other alicyclic hydrocarbons, benzene, toluene, xylene, Hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene and other benzenes with long chain alkyl groups Aromatic hydrocarbons, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane and other halogenated hydrocarbons, carboxylate or other various oils, etc., can be used alone or as a mixture of these substances Use with surfactants. the

In addition, electrophoretic particles are organic or inorganic particles (polymers or colloids) having a property of electrophoretic movement based on a potential difference in a liquid-phase dispersion medium. the

As the electrophoretic particles, for example, black pigments such as aniline black, carbon black, and titanium black, white pigments such as titanium oxide, zinc white, and antimony trioxide; azo pigments such as monoazo, disazo, and polyazo can be used; Isoindolinone, color molybdenum lead, yellow iron oxide, cadmium yellow, titanium yellow, antimony yellow and other yellow pigments; monoazo, disazo, polyazo and other nitrogen pigments; quinacridone red, chromium Red pigments such as vermilion; blue pigments such as phthalocyanine blue, indanthrene blue, anthraquinone dyes, navy blue, ultramarine blue, and cobalt blue; and green pigments such as phthalocyanine green, etc., or two or more. the

Furthermore, to these pigments, electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, charge control agents composed of particles such as mixtures, titanium-based coupling agents, aluminum-based coupling agents, Dispersants such as silane coupling agents, lubricants, stabilizers, etc. the

As the material forming the wall membrane of the microcapsule 6, a composite membrane of gum arabic and gelatin, a compound such as polyurethane resin, urea resin, or urea resin can be used. the

Furthermore, in the electrophoretic display device 1 of this example, two kinds of electrophoretic particles are enclosed in the microcapsule 6 , one of which is negatively charged and the other is positively charged. As these two types of electrophoretic particles, titanium oxide as a white pigment, and carbon black as a black pigment are used. Therefore, by using such two types of electrophoretic particles, white and black, for example, when representing numerals and the like, numerals and the like can be displayed using black electrophoretic particles. the

In addition, only one type of electrophoretic particle may be used to perform display by swimming to the common electrode 4 side or the pixel electrode 2 side. the

In addition, these microcapsules 6 are especially on the common electrode 4 bonded to the second substrate 5 with the adhesive 10 . As the binder 10, a material having excellent affinity with the wall membrane of the microcapsule 6, good adhesion to the common electrode 4, and excellent insulating properties can be used. Such as polyethylene, polyvinyl chloride, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene, ABS resin, methyl methacrylate resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, Vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylate copolymer, vinyl chloride-methacrylic acid copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol-vinyl chloride copolymer, propylene-vinyl chloride copolymer Thermoplastic resins such as vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl formal, cellulose resin, polyamide resin, polyacetal, polycarbonate, polyethylene terephthalate Glycol ester, polybutylene terephthalate, polyphenylene ether, polysulfone, polyamideimide, polyaminobismaleimide, polyethersulfone, polyphenylenesulfone, polyarylate , grafted polyphenylene ether, polyether ether ketone, polyetherimide and other polymer compounds, polytetrafluoroethylene, polyfluoroethylene propylene, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, ethylene-tetrafluoroethylene Fluorine resins such as vinyl fluoride copolymers, polyvinylidene fluoride, polychlorotrifluoroethylene, and fluorine rubber; silicone resins such as silicone resins and silicone rubber; in addition, methacrylic acid-styrene copolymers, polybutylene , methyl methacrylate-butadiene-styrene copolymer, etc. the

On the one hand, these microcapsules 6 are fixed on the pixel electrodes 2 of the first substrate 3 through the double-sided adhesive sheet 11 . The double-sided adhesive sheet 11 is formed of a viscous material such as rubber or acrylic with a thickness of about 25 μm, and is bonded to the pixel electrode 2 of the first substrate 3 and to the microcapsule 6 to secure the microcapsule. 6 remains bonded to the first substrate 3. the

According to such a structure, the microcapsule 6 is sandwiched between the first substrate 3 and the second substrate 5 to form the display area 9. the

As shown in FIG. 2 , a conductive portion 7 is formed on a display region 9 of the first substrate 3 . A conductive material 17 is formed on the conductive portion 7 as shown in FIG. 1 , and the conductive material 17 is in electrical contact with the common electrode 4 of the second substrate 5 . Thus, in the present embodiment, the vertical conduction member 12 for vertically conducting the first substrate 3 and the second substrate 5 is constituted by the conductive portion 7 and the conductive material 17 . the

Conductive portion 7 is formed of a copper foil pattern by, for example, a semi-additive method. Therefore, it can be formed by the same process and the same material as the above-mentioned segment electrodes 2a, 2b, dummy electrodes 16, and the like. the

In addition, the conductive material 17 is composed of a conductive paste made of metal particles such as silver, nickel particles formed by crushing, carbon particles, and a conductive sheet obtained by processing the conductive paste into a sheet shape. Conductive particles such as nickel-plated and gold-plated particles on a resin core are mixed and contained in resin such as epoxy resin. Furthermore, especially regarding the resin, it is preferable to use a rubber-based or acrylic-based resin as a resin having adhesiveness at room temperature. the

2 (a) and (b), on the outer periphery of the display element 20, a pair of waterproof sheets 14, 14 are laminated to sandwich the display element 20, so that the entire display element 20 is covered by the pair of waterproof sheets 14. , 14 covered status. In addition, on the periphery of each of the pair of waterproof sheets 14, sticking portions 14c, 14c formed larger than the outer shapes of the first substrate 3 and the second substrate 5 are provided. Then, the waterproof sheet 14 and the sticking parts 14c, 14c are bonded together on the side circumference of the display element 20 by the adhesive 18 . the

The waterproof sheet 14 has a two-layer structure including a resin layer 14a made of a polymer material and a barrier layer 14b made of an inorganic material. When sealing a pair of substrates with the waterproof sheet 14, the barrier layer 14b of the waterproof sheet 14 is disposed closer to the substrate side (inner side) than the resin layer 14a. In the case where the barrier layer 14b is arranged on the outside, moisture intrudes into the inside from the defect portion generated on the barrier layer 14b. On the other hand, by arranging the barrier layer 14b of the waterproof sheet 14 closer to the substrate side than the resin layer 14a, even if a defective part occurs in the barrier layer 14b, the external resin layer 14a can cut off moisture or the like from the outside. intrusion. As means for further improving waterproofness, resin layers 14a and barrier layers 14b may be laminated alternately to further enhance the effect of cutting off the ingress of moisture from the outside by multilayering. the

As the material of the barrier layer 14b, inorganic materials such as silicon oxide, silicon nitride, aluminum oxide, and titanium oxide, or metal foils such as aluminum foil, copper foil, and Kovar foil are preferably used. the

As the material of the resin layer 14a, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyethersulfone (PES), polyethylene terephthalate ( Polyester such as PEN), resin such as polycarbonate (PC), or metal foil such as aluminum foil, copper foil, Kovar foil, or metal thin film and resin film. the

In addition, an adhesive 18 is attached to the side circumference of the display element 20 , and the space between the first substrate 3 and the second substrate 5 is sealed with the adhesive 18 . As the material of the binder 18, resin binders such as epoxy resins, silicone resins, or acrylic resins, or resin binders containing inorganic material fillers such as silicon nitride are preferably used. the

According to the present embodiment, since the dummy electrodes 16 are formed along the outer periphery of the segment electrode group 2c, the step between the substrate surface on which no segment electrodes are provided due to the dummy electrodes 16 and the segment electrodes 2 becomes gentle. Thus, the gap between the microcapsule 6 and the second substrate 5 disposed at the peripheral portion between the pair of substrates 3 and 5 is filled. Therefore, when the display element 20 is sealed with the waterproof sheet 14, the peripheral portion of the second substrate 5 is supported by the pixel electrode 2 and the microcapsule 6, and the stress (stress) of the peripheral portion of the substrate when the waterproof sheet 14 is pressed (deep drawn) concentrated reduction. Thereby, the deformation of the peripheral portion of the first substrate 3 and the second substrate 5 disappears, the rupture of the microcapsules 6 disposed on the peripheral portion of the first substrate 3 and the second substrate 5 can be prevented, and the deformation at the peripheral portion of the display area 9 is released. The display of is not good. the

In addition, according to the present embodiment, since the dummy electrode 16 is formed of the same material as the pixel electrode 2 , it is possible to reduce the cost of the material. Furthermore, the dummy electrode 16 can be formed in the same process as that of the pixel electrode 2 , and there is no need to add an additional process for forming a pad for the dummy electrode 16 . the

(Manufacturing method of electrophoretic display device)

Next, a method of manufacturing the electrophoretic display device of this embodiment will be described with reference to FIG. 3 . 3( a ) to ( d ) are cross-sectional views showing the manufacturing process of the electrophoretic display device 1 . the

First, as shown in FIG. 3( a ), an elastically deformable first substrate 3 made of polyimide with a thickness of about 25 μm is prepared, and the display area 9 of the first substrate 3 is formed by a known method such as a semi-additive method. The pixel electrode 2 (segment electrode) and the dummy electrode 16 are formed simultaneously. the

的由ITO构成的透明电极(共用电极4)。  In addition, as shown in FIG. 3( b ), an elastically deformable second substrate 5 made of polyethylene terephthalate (PET) having a thickness of approximately 200 μm was prepared. In addition, on the entire surface of one side (inner surface) side of the second substrate 5, a film with a thickness of about several hundreds is formed by vapor deposition.

A transparent electrode (common electrode 4) made of ITO.

Then, as shown in FIG. 3( b ), a plurality of microcapsules 6 are arrayed with an adhesive 10 on the surface of the common electrode 4 of the second substrate 5 . Positively and negatively charged black and white particles are jointly contained in the microcapsule 6, and the diameter thereof is 30-50 μm. Next, a double-sided adhesive sheet (not shown) is bonded to the surface of the microcapsule opposite to the side of the microcapsule bonded to the second substrate 5 . the

Then, the second substrate 5 bonded with the double-sided adhesive sheet in this way is placed on the first substrate 3 so as to face it. As shown in FIG. 3(c), press the double-sided adhesive sheet of the second substrate 5 to the side where the pixel electrode 2 is formed on the first substrate 3 to bond the double-sided adhesive sheet, and bond the pair of substrates. between. Thus, the display element 20 in which the microcapsules are sandwiched between the first substrate 3 and the second substrate 5 is formed. And here, when performing the bonding by the double-sided adhesive sheet, heating is basically not required, and it is carried out at room temperature, and if necessary, heating is carried out within the range that does not adversely affect the microcapsules 6. . the

Then, as shown in FIG. 3( d), in the side circumference including the display element 20 between the first substrate 3 and the second substrate 5, the adhesive is injected from the outer peripheral side by using a diffusion device, and the outer side surrounding the display area 9 location to dispense the adhesive. Thereafter, the electrophoretic display device 1 is obtained by curing this to form the adhesive layer 13 . As the adhesive 13 , an adhesive that can be cured without heating, such as an ultraviolet radiation curing type, can be used. However, it is also possible to use an adhesive that can be cured by heating within a range that does not adversely affect the microcapsules 6 in the same manner as the above-mentioned adhesive treatment of the double-sided adhesive sheet. the

Second Embodiment

Hereinafter, this embodiment will be described with reference to the drawings. the

In the above-described embodiment, the dummy electrode 16 having the same constituent material as the pixel electrode is formed as a liner for filling the step. On the other hand, this embodiment differs from the above-mentioned first embodiment in that a solder resist for protecting lead wires and the like is used as a spacer. In addition, since the basic configuration of other electrophoretic display devices is the same as that of the above-mentioned first embodiment, the same reference numerals are assigned to common structural elements, and detailed description thereof will be omitted. the

FIG. 4 is a cross-sectional view showing a schematic configuration of an electrophoretic display device in which dummy patterns 22 are formed. As shown in FIG. 4, on the protruding portion 3a of the first substrate 3, a terminal portion 8 on which an FPC is mounted is formed. In addition, a solder resist (not shown) is arranged on the outer periphery of the terminal portion 8 so that the adhesive does not adhere to other parts than necessary when mounting the FPC board. the

In addition, lead wires (not shown) for connecting the terminal portion 8 and the electrodes 2 and 4 of the display region 9 are formed on the extension portion 3 a. Furthermore, solder resist 32 for protecting the leads is arranged on the leads. As the material of the solder resist 32 , for example, epoxy resin-based, phenol-based, or polyurethane-based materials can be used, but epoxy resin-based materials are preferably used in terms of strength. the

In this embodiment, in the gap S between the segment electrodes 2a', 2b' arranged on the outside of the three segment electrode groups 2c, 2c, 2c and each side (outer peripheral edge) of the first substrate 3, a dummy is formed. Pattern 22 (pad). The dummy pattern 22 is constituted by the solder resist 32 arranged on the outer periphery of the above-mentioned protruding portion 3 a and on the leads. Therefore, the dummy pattern 22 is formed by the same process as the process of disposing the solder resist 32 on the outer periphery of the terminal portion 8 of the extension portion 3a and on the leads. At this time, since the solder resist 32 is an insulating material, it does not matter even if it contacts the segment electrodes 2 formed in the display region 9 . the

According to the present embodiment, since the dummy pattern 22 is formed of the same material as the solder resist 32 provided on the overhang portion 3a, cost reduction of the material can be achieved. Furthermore, the dummy pattern 22 can be formed in the same process as that of the solder resist 32 , and it is not necessary to add an additional process for forming the dummy pattern 22 . the

Furthermore, in the above-mentioned embodiment, although the dummy pattern 22 is formed of the same material as the solder resist 32 provided on the overhanging portion 3a, when the material arranged on the overhanging portion 3a is different from the above-mentioned material, the different material may be used. material formed. It may also be formed with an insulator of a material different from the material arranged on the overhanging portion 3a. the

The third embodiment

Hereinafter, this embodiment will be described with reference to the drawings. the

This embodiment differs from the above-described first embodiment in that a copper pattern 24 and a resist film 26 are formed on the outer surface side of at least one of the first substrate 3 and the second substrate 5 . In addition, since the basic configuration of other electrophoretic display devices is the same as that of the above-mentioned first embodiment, the same reference numerals are assigned to common constituent elements, and detailed description thereof will be omitted. the

5( a ) and ( b ) are cross-sectional views showing a schematic structure of the electrophoretic display device 1 in which the reinforcing member 28 is formed. the

On the outer surface side of the first substrate 3, a reinforcing member 28 for increasing the rigidity of the first substrate 3 is formed. As shown in FIGS. 5( a ) and ( b ), the reinforcing member 28 is formed at a position at least partially overlapping the dummy electrodes 16 (dummy patterns 22 ) formed on the inner surface side of the first substrate 3 in planar view. In this embodiment, like the dummy electrode 16, the reinforcing member 28 may be formed on the entire circumference of the above-mentioned corresponding position on the outer surface side of the first substrate 3 as shown in FIG. A part of the above-mentioned position of the substrate 3 is formed. the

The reinforcing member 28 is formed by laminating a copper pattern 24 (conductive member) made of a conductive material such as copper, and a resist film 26 covering the copper pattern 24 . The copper pattern 24 is made of the same material as the segment electrodes 2 formed on the first substrate 3 . The width of the copper pattern is approximately 0.5 mm, or preferably greater than that, and the film thickness of the copper pattern is approximately 18 μm, or preferably greater than that. In addition, the resist film 26 is made of the same material as the solder resist 32 for protecting the leads formed on the first substrate 3 . The width of the resist film 26 is approximately 0.5 mm, or preferably greater than that, and the film thickness of the resist film 26 is approximately 15 μm, or preferably greater than that. the

According to the present embodiment, since the reinforcing member 28 is made of the same material as the segment electrodes 2a and 2b and the solder resist 32 provided on the opposite surface side of the first substrate 3, material cost reduction can be achieved. Thus, by making the reinforcing member 28 a two-layer structure of the copper pattern 24 and the resist film 26, the rigidity of the substrate can be further improved. the

As a result, the concentration of stress (stress) on the peripheral edge of the substrate when the waterproof sheet 14 is pressed (deep drawn) is reduced, and the rupture of the microcapsules 6 disposed on the peripheral edge of the first substrate 3 and the second substrate 5 can be prevented, and the display can be eliminated. The display of the peripheral portion of the area 9 is poor. the

Furthermore, even if the reinforcing member 28 is formed of the single-layer copper pattern 24 or the resist film 26, the rigidity of the substrate can be improved. the

In this embodiment, although the copper pattern 24 and the resist film 26 are formed only on the outer surface side of the first substrate 3, the copper pattern 24 and the resist film 26 may be formed only on the outer surface side of the second substrate 5. resist film 26 . In addition, copper patterns 24 may be formed on both substrates 3 and 5 . the

Furthermore, the copper pattern 24 can also function as wiring for electrically connecting the electrophoretic display device 1 and the main body of the electronic device when the electrophoretic display device 1 is mounted in the main body of the electronic device. the

(Electronic equipment)

Next, the electronic device of the present invention will be described. An electronic device of the present invention includes the aforementioned display device of the present invention. the

Hereinafter, an electronic device equipped with the display device will be described as an example. the

watch

First, an example in which the electrophoretic display device is applied to a display unit of a wristwatch will be described. FIG. 6 is a perspective view showing a schematic configuration of the wristwatch 50 . As shown in FIG. 6 , the wristwatch 50 includes a display unit 56 for displaying the time, a case 52 provided as an outer frame of the display unit 56 , and a band 54 attached to the case 52 . The wristwatch 50 of the present embodiment has a curved display part 56 and has a shape that can be wound around the wrist of the user of the wristwatch 50 . the

mobile phone

Next, an example in which the display device is applied to a display unit of a mobile phone will be described. FIG. 7 is a perspective view showing the structure of the mobile phone. As shown in FIG. 7 , this mobile phone 90 includes a receiver 92 , a microphone 93 , and the aforementioned display device 64 in addition to a plurality of operation keys 91 . the

electronic paper

Next, an example in which the display device is applied to a display unit of electronic paper will be described. FIG. 8 is a perspective view showing the structure of the electronic paper. The electronic paper 110 includes a main body 111 made of a rewritable sheet having the same texture and flexibility as paper, and a display unit including the aforementioned display device 64 . the

According to such electronic equipment, since the electrophoretic display device 1 free from display defects is provided, highly reliable and high-quality electronic equipment can be provided. the

Moreover, as the above-mentioned electronic equipment, in addition to the wristwatch of FIG. 6, the mobile phone of FIG. 7, and the electronic paper of FIG. , and e-books, viewfinder-type, monitor-type video recorders, car navigation devices, pagers, portable computers, calculators, word processors, workstations, videophones, POS terminals, touch panels, etc. the

In addition, the technical scope of the present invention is not limited to the above-mentioned embodiments, and various modifications can be made to the above-mentioned embodiments without departing from the scope of the present invention. the

In the above-mentioned embodiment, the dummy electrodes (dummy patterns) are formed in a frame shape along the outer periphery of the segment electrodes, but as long as the dummy electrodes are formed on at least a part of the outer peripheries of the segment electrodes, the stress on the edge of the substrate can be reduced. Concentration prevents breakage of the microcapsules disposed on the peripheral edge of the pixel electrode. the

In addition, as the driving method of the electrophoretic display device, besides the segment type, an active matrix method and a passive matrix method may be adopted. the

Furthermore, in the above-mentioned embodiment, seven segment electrodes are used to constitute the segment electrode group, but the present invention is not limited to this, and the segment electrode group 2c may be constituted by 14 or 16 segment electrodes. In addition, the arrangement pattern of the segment electrodes is not limited to the arrangement pattern of the above-mentioned embodiment. the

Claims (6)

1. an electrophoretic display apparatus is characterized in that, wherein utilizes diaphragm to cover display element,

The micro-capsule of the display material that optical characteristics changes in response to electro photoluminescence has been enclosed in this display element clamping between the 1st substrate and the 2nd substrate,

Said the 1st substrate be provided with the 1st electrode with said the 2nd substrate forward surface side in opposite directions, and said the 2nd substrate be provided with the 2nd electrode with said the 1st substrate forward surface side in opposite directions,

The neighboring of the said forward surface side of said the 1st substrate and said the 1st gaps between electrodes are provided with liner,

The thickness of said liner be said the 1st electrode thickness 30%～180%,

Be set to along the effective width of said liner of radiation orientation measurement at circumference 2 times of diameter of said micro-capsule or more than, this effective width is meant that said micro-capsule and said liner plane earth see the effective width of coincidence.

2. electrophoretic display apparatus according to claim 1 is characterized in that, said the 1st electrode is a pixel electrode, and said the 2nd electrode is common electrode,

Said pixel electrode is made up of a plurality of segment electrodes that are arranged as predetermined pattern,

Said liner is configured in the periphery of the said segment electrode that is arranged in the outside in said a plurality of segment electrode.

3. electrophoretic display apparatus according to claim 2 is characterized in that, said liner utilization and said pixel electrode identical materials are provided with.

4. electrophoretic display apparatus according to claim 2 is characterized in that, said the 1st substrate has the extension that stretches out from the profile of said the 2nd substrate,

Said extension is provided with portion of terminal, and the said extension except said portion of terminal is provided with dielectric film at least,

Said liner utilization and said dielectric film identical materials are provided with.

5. electrophoretic display apparatus according to claim 4; It is characterized in that; With the face of the said forward surface side opposition side of at least one side's substrate of said the 1st substrate and said the 2nd substrate on, to have at least a part of plane earth to see that the mode that overlaps is provided with strengthening part with the said liner of the forward surface side of said the 1st substrate.

6. electrophoretic display apparatus according to claim 5; It is characterized in that; Said strengthening part has at least one side of conductive component and guard block; Said conductive component is made up of the said pixel electrode identical materials with the forward surface side that is arranged on said the 1st substrate, and said guard block is by constituting with said dielectric film identical materials.

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