JP3099048B2 - Electrophoretic display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a display electrode pattern, a background electrode pattern, and a connection between these background electrode patterns among electrode patterns required for required display driving. By providing a gap formed between the connection patterns and a concealing portion for concealing at least a portion corresponding to the extraction pattern of the display electrode pattern, unnecessary display can be surely prevented so that visibility is improved. The concealing part is formed integrally with the porous spacers when configuring a dispersed-system split-type electrophoretic display device, thereby reducing the number of parts and simplifying the device configuration. It relates to the intended electrophoretic display device.

“Prior art” This type of electrophoretic display device has a configuration in which a dispersion system in which electrophoretic particles are dispersed in a liquid dispersion medium is sealed between a pair of electrode plates arranged so that at least one of them is transparent. According to the configuration, desired characters, symbols, figures, and the like can be displayed while controlling the polarity so that the electrophoretic particles in the dispersion medium can be adsorbed or separated from the transparent electrode plate side according to the polarity.

Examples of the dispersion medium used in the dispersion system of such an electrophoretic display device include aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, various esters, alcohol solvents, halogenated hydrocarbons, and other various kinds. The oils and the like are used alone or in a suitable mixture as general ones.
In addition, in the electrophoretic particles, titanium oxide or barium sulfate as a white substance, and other inorganic pigments as described above as a yellow substance, some organic pigments and the like are considered to be excellent in terms of hiding power. . Further, oil-soluble dyes, disperse dyes, and the like can be used to dye the liquid dispersion medium into various colors in order to ensure the contrast with the color of the electrophoretic particles. In addition, when the liquid dispersion medium is not colored, there is a method using electrophoretic particles having two kinds of opposite charges.

In addition, various surfactants and various additives can be added to the dispersion system as means for improving the dispersibility of the electrophoretic particles, improving the electrophoretic property of the electrophoretic particles, that is, improving the display property, or ensuring long life as a display device. .

As shown in FIG. 3, such an electrophoretic display device has two transparent electrode members, each having a required display electrode pattern 2 and 4 formed on the opposing surface thereof using an appropriate transparent conductive member such as indium tin oxide. It has a structure in which glass plates 1 and 3 are provided, and a sealing member 5 also serving as a spacer is provided on an outer peripheral portion so as to enclose a dispersion system 7 in which electrophoretic particles 6 are dispersed in a liquid dispersion medium between the opposed gaps. In the display operation, the electrode patterns 2, 4
Of the dispersion system 7 while changing the distribution state of the electrophoresis particles 6 under the action of an electric field on the dispersion system 7 so that a display driving voltage is applied to the electrophoresis particles 6 so that the electrophoresis particles 6 can be adsorbed and separated from the electrode patterns 2 and 4. In this case, a desired display operation is performed by changing the target characteristic.

[Problem to be Solved by the Invention] In the electrophoretic display device as described above, with respect to the display-side electrode plate, a display electrode pattern necessary for a required display is formed and a required electrode pattern is formed according to the display electrode pattern. A background electrode pattern is formed as a means for increasing the contrast with the portion other than the display of
In the case of a structure in which a uniform common electrode is formed on the other electrode plate, required display is performed by applying display drive voltages of opposite polarities to the display electrode pattern and the background electrode pattern. Control can be performed.

However, when the portion 11A of the extraction pattern is located in the region where the porous portion 12A of the porous spacer 12 is formed when the porous spacer is used when the portion 11A of the extraction pattern is used as the sealing region of the dispersion system 7, the display drive for the electrode pattern 11 is performed. With the application of the voltage, the dispersing system 7 of the extraction pattern portion 11A changes its color at the same time and is visually recognized as unnecessary display, which is a serious obstacle in practical use. In the case of patterning as shown in FIG. 1, such an unnecessary display portion corresponds to a portion of a drawer pattern including a to f shown as a connection pattern, which is painted out in black.

"Object and Configuration of the Invention" The present invention relates to an electrophoretic display device in which an extraction pattern for applying a display driving voltage to an electrode pattern is configured as simply as possible. To provide an electrophoretic display device with good contrast.

For this purpose, the electrophoretic display device according to the present invention includes a display control voltage applied between the electrodes by enclosing a dispersion system including electrophoretic particles between a pair of transparent electrodes arranged at least one side. By changing the distribution state of the electrophoretic particles in the dispersion under the action of the above, a change is made to the optical reflection characteristic to perform a required display operation, and each of the electrodes corresponding to a display background among the electrodes Are connected to each other, a required display electrode pattern including the background electrode pattern is formed on one of the opposed electrode plates, and a uniform common electrode is formed on the other electrode plate. In the electrophoretic display device configured to be formed, the display electrode pattern, the background electrode pattern, and the background electrode pattern are connected to each other. A gap formed between the mutually connection pattern, which is constituted to have a hiding part for hiding the portion corresponding to the lead pattern of at least the display electrode pattern.

In addition, by forming the concealing portion in the porous spacer for dividing and enclosing the dispersion system in the discontinuous phase between the counter electrode plates, the number of parts is reduced and the apparatus configuration is simplified. It is also possible to aim.

"Example" Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiment. FIG. 1 shows an example of a display-side electrode plate having a numeric pattern in connection with the conventional structure shown in FIG. FIG. 5 is a conceptual plan view of a display-side electrode plate for explaining the present invention for convenience, and the same reference numerals as those in FIG. 4 indicate the same components. In the figure, segments A to G are used as display electrode patterns necessary for numeric display.
Is connected to each of the drawer patterns as in the prior art. Background electrode patterns a to
f is connected to each other at six connection patterns a to f disposed between both ends of each segment, and is connected to a common lead pattern at both connection patterns e and f. When a desired display panel is formed by forming a plurality of digits of the above-mentioned numeric pattern, the layout of the entire display electrode pattern including the background electrode pattern can be simplified and the design flexibility can be greatly increased. Also, it is extremely advantageous when a small and high-density display panel is formed, and it can be adopted regardless of the type of the dispersed system or the continuous phase type.

As shown in FIG. 2, the electrophoretic display device of the present invention prepares a transparent glass plate 10 as a base material for forming a transparent display-side rigid electrode plate, and has tin oxide, indium oxide, Each segment A described above together with each drawing pattern using a transparent conductive material such as tin (ITO)
A required electrode pattern 11 including a display electrode pattern consisting of 〜G and a background electrode pattern aａf is appropriately formed, and, for example, a dispersion system is divided into small sections and sealed on the upper surface of the rigid electrode plate. A porous spacer 12 made of a swelling or elastic member for
On the upper surface of 12, a flexible electrode plate provided with a film base 13 having a uniform common electrode pattern 14 formed on the surface facing the electrode pattern 11 on the rigid electrode plate side can be arranged. . Here, the flexible electrode plate is connected to the porous spacer 12.
The excessive dispersion system 7 supplied to the respective holes is pressed from the upper surface of the flexible electrode plate by applying a pressing force to the spacers 12 while the excess dispersion system 7 is sequentially pushed out, and the flexible electrode plate and the spacers are pushed out. By performing the bonding process using the fixing adhesive 17 at the portion of the adhesive fixing portion 16 with the periphery of the periphery 12, it is possible to completely enclose the dispersion system 7 without voids in each hole of the spacer 12. The structure is as follows.

The electrode pattern 14 does not pose a problem because a shared uniform electrode is sufficient, but the display-side electrode pattern 11 is formed on a glass substrate in various modes depending on the purpose of display, as shown in FIG. As described above, as shown in the drawing pattern, for example, a part of the drawing pattern is indicated by reference numeral 11A. When the display driving voltage is applied to the electrode pattern 11, the extraction pattern portion 11A
However, they also change color and are recognized as unnecessary display at the same time, which is a major obstacle in practical use. In the case of patterning as shown in FIG. 1, such an unnecessary display portion corresponds to a portion of a drawer pattern including a to f shown as a connection pattern, which is painted out in black.

Therefore, as a means for preventing such unnecessary display, a place where such a drawn pattern portion 11A is formed has a thickness equivalent to that of the porous spacer 12 and is transparent or inactive in display of the same color as the dispersion medium of the dispersion system 7. It is preferable to provide a concealing portion 15 for the drawer pattern portion 11A which can be constituted by a member.

By the way, as shown in FIG. 1, the lead pattern portion 11A is used to insulate the display electrode pattern 11 composed of other lead patterns and display segments A to G and the background electrode patterns a to f therefor. The electrophoretic particles are arranged adjacent to each other via the gap S, and although no electric field acts on such a gap S, the electrophoretic particles gradually move to the gap S and constantly move irrespective of the display switching operation. Since it is visually recognized as an unnecessary display, the concealing portion 15 as described above includes the gap S and the drawing pattern portion 11.
As shown in FIG. 2, it is optimal to integrally form with the porous spacer 12 so that both can be concealed corresponding to A.

The porous spacer 12 having the drawer pattern portion 11A and the concealing portion 15 for the gap S and the required porous portion 12A arranged in the display area has a styrene-butadiene-based, isoprene-based, ethylene- Propylene-based, acrylonitrilo-butadiene-based, swellable material composed of synthetic rubber such as chloroprene-based or natural rubber or various resins with low crystallinity, or synthetic rubber such as silicon rubber, urethane rubber, fluorine rubber or acrylic rubber, An elastic member made of a material such as natural rubber is prepared, and a sheet-like molded product formed with a required porous portion 12A together with a gap concealing portion 15 by an appropriate means such as a punch or a laser is used as an electrode of a rigid electrode plate. Bonding to the pattern 11 side,
Alternatively, such a swelling or elastic member can be directly formed integrally with the electrode pattern 11 side by screen printing means, spraying means or the like. The porous spacer 12 is preferably made of a transparent material or of the same color as the dispersion medium of the dispersion system 7 in order to improve the display contrast.

On the other hand, as the electrophoretic particles used in the dispersion system 7, fine powders of various organic and inorganic pigments, dyes, ceramics, resins, and the like can be used as appropriate, in addition to titanium oxide, zinc sulfide, and various known colloidal particles. As the dispersion medium of the dispersion system 7, various kinds of natural or synthetic oils and the like can be arbitrarily used in addition to hydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons and the like. If necessary, the dispersing system 7 may contain a dispersant, a lubricant or a stabilizer in addition to an electrolyte, a surfactant, a metallic soap, and a charge control agent composed of particles such as resin, rubber, oil, varnish, and compound. An agent and the like can be appropriately added. Furthermore,
In addition to unifying the charge of the electrophoretic particles to positive or negative, increasing the zeta potential, it is also possible to appropriately adjust the adsorptivity of the electrophoretic particles to the electrode patterns 11 and 14 and the viscosity of the dispersion medium.

In one embodiment, as electrophoretic particles, 10 g of titanium oxide composed of 600B manufactured by Teikoku Chemical Industry Co., Ltd., 34 g of hexylbenzene as a dispersion medium, and O as a coloring dye manufactured by Chuo Gosei Co., Ltd.
Prepare 0.4 g of an oil-soluble blue dye composed of BBA, and 1.5 g of sorbitan sesquiolate as a dispersant.
The mixture is sufficiently mixed in a ball mill for a predetermined time to prepare a display dispersion system 7 in advance, and a patterned 1.1 mm-thick ITO glass plate as shown in FIG. A 25 μm thick ITO PET film was manufactured on each of the flexible electrode plates. On the ITO glass plate, as shown in the figure, a porous portion 12A required by a screen printing method using a transparent silicon rubber and having a thickness of 40 μm and the concealing portion 15 described above are used.
Was formed.

Next, as shown in FIG. 2, the flexible electrode plate is superposed on the porous spacer 12 such that the electrode pattern 14 faces the electrode pattern 11 of the display-side rigid electrode plate, and the upper surface of the flexible electrode plate is The flexible electrode plate is brought into close contact with the porous spacer 12 by sequentially applying a pressing force to the porous portion 12 with a heating roller or the like.
When the excess dispersion is pushed out from each hole of A, the proper encapsulation of the dispersion 7 is performed. Therefore, when the members 17 are fixed with an adhesive 17 using an adhesive fixing portion 16 such as hot melt,
The process of completely encapsulating the divided dispersion system without any non-injection into the porous spacer 12 and the process of joining the members can be easily and quickly performed.

[Effect of the Invention] The electrophoretic display device according to the present invention is an electrophoretic display device capable of performing the patterning as described above, including a concealing portion for suitably preventing unnecessary display of a display area. Since such a configuration is easy, it is possible to provide an electrophoretic display device with good visibility and high practicality.

The concealing portion for preventing unnecessary display as described above can be easily configured so as to conceal a gap formed between the drawing electrode pattern and the display electrode pattern including the background electrode pattern. Unnecessary display can also be reliably prevented.

In the case where the concealing portion for preventing unnecessary display as described above constitutes a distributed system electrophoretic display device, the concealing portion is integrally formed with a porous spacer for that purpose to reduce the number of parts and simplify the device configuration. Can be achieved.

Therefore, it is possible to ensure a display operation with good display without display defects and to manufacture various electrophoretic display devices with high durability and high reliability against repeated display operations at low cost in combination with the simplicity of manufacturing means. Can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a patterning process according to the present invention so as to have a lead pattern including an electrode pattern for a numeric, an electrode pattern for a background, and an interconnection pattern for the electrode pattern for a background. FIG. 2 is a conceptual enlarged plan view of the display-side electrode plate, and FIG. 2 is a drawing pattern portion including an interconnecting pattern for a background electrode pattern on the display-side electrode plate; FIG. 3 is a conceptual enlarged cross-sectional configuration view of a main part of a dispersion type electrophoretic display device having a porous spacer formed with a concealing portion for preventing an unnecessary display portion due to a gap formed in a conventional structure. FIG. 4 is a conceptual cross-sectional configuration diagram of an electrophoretic display device according to FIG. FIG. 5 is a conceptual enlarged plan configuration diagram of a display-side electrode plate showing an arrangement mode of a drawer pattern necessary for FIG. 1, 3: transparent glass plate 2, 4: electrode pattern 5: end spacer 6: electrophoretic particles 7: display dispersion system A to G: display segment a to f: background electrode F: Interconnection pattern 10: Transparent glass plate 11: Electrode pattern 11A: Drawer pattern portion 12: Porous spacer 12A: Porous portion of spacer 13: Film substrate 14: Common electrode pattern 15: Concealed portion of connection pattern 16: Adhesive fixing part 17: Adhesive for fixing S: Gap

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Mori 757 Tenhoki, Kusazaki-cho, Inashiki-gun, Ibaraki Japan Nippon Mektron, Inc. In the Minato-Ibaraki Plant of Ktron Co., Ltd. (56) References JP-A-53-30299 (JP, A) JP-A-1-300232 (JP, A) JP-B-51-14876 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) G09F 9/37 G09F 9/30 342

Claims (2)

(57) [Claims] 1. A dispersion system containing electrophoretic particles is enclosed between a pair of electrode plates, at least one of which is transparent, which is disposed opposite to each other. By changing the distribution state of the electrophoretic particles to change the optical reflection characteristics to perform a required display operation, and to connect the electrodes corresponding to the display background among the electrodes to each other, An electrophoretic display in which a required display electrode pattern including the background electrode pattern is formed on one electrode plate of the counter electrode plate, and a uniform common electrode is formed on the other electrode plate. In the apparatus, the display electrode pattern, the background electrode pattern, and the connection pattern that connects the background electrode patterns to each other are formed between the connection patterns. An electrophoretic display device having a concealing portion for concealing a portion corresponding to a gap corresponding to at least a drawing pattern of the display electrode pattern. 2. The electrophoretic display device according to claim 1, wherein said concealing portion is formed between said counter electrode plates in a porous spacer for dividing and enclosing said dispersion system into a discontinuous phase.