JP2013092701A - Electrowetting display - Google Patents

Electrowetting display Download PDF

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JP2013092701A
JP2013092701A JP2011235566A JP2011235566A JP2013092701A JP 2013092701 A JP2013092701 A JP 2013092701A JP 2011235566 A JP2011235566 A JP 2011235566A JP 2011235566 A JP2011235566 A JP 2011235566A JP 2013092701 A JP2013092701 A JP 2013092701A
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water
insulating film
repellent insulating
contact angle
voltage
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Isao Adachi
勲 安達
Osamu Sato
治 佐藤
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LG Display Co Ltd
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LG Display Co Ltd
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/004—Optical devices or arrangements for the control of light using movable or deformable optical elements based on a displacement or a deformation of a fluid
    • G02B26/005—Optical devices or arrangements for the control of light using movable or deformable optical elements based on a displacement or a deformation of a fluid based on electrowetting
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/004—Optical devices or arrangements for the control of light using movable or deformable optical elements based on a displacement or a deformation of a fluid
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/133345—Insulating layers
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1343—Electrodes
    • G02F1/134309—Electrodes characterised by their geometrical arrangement
    • G02F1/134363—Electrodes characterised by their geometrical arrangement for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1343—Electrodes
    • G02F1/13439—Electrodes characterised by their electrical, optical, physical properties; materials therefor; method of making
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3433—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices

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  • General Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
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  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
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Abstract

PROBLEM TO BE SOLVED: To provide an electrowetting display which can control an aggregated position of colored oil when voltage is applied to pixels.SOLUTION: Provided is an electrowetting display which is formed in that a water-repellent insulating film is formed on a transparent electrode 2 formed on a substrate 1, a grating-shaped barrier rib 5 is formed on the film, colored oil is filled in an area surrounded by the barrier rib 5, water is filled in an area above the area, and the rib is adhered with a counter substrate on which a transparent electrode is formed. As the water-repellent insulating film, a first water-repellent insulating film 3 and a second water-repellent insulating film 4, whose contact angles to water are equal when no voltage is applied and in which characteristics of the contact angles varying with rise of applied voltage are different, are used. As the second water-repellent insulating film 4, a water-repellent insulating film, in which a difference between the contact angles changes by a predetermined angle or more or saturates before the contact angle of the first water-repellent insulating film 3 starts to change due to rise of applied voltage, is used.

Description

本発明は、エレクトロウェッティング現象を用いたエレクトウェッティングディスプレイに関する。   The present invention relates to an electwetting display using an electrowetting phenomenon.

エレクトロウェッティングディスプレイは、透明電極上に撥水性（疎水性）の絶縁膜を形成し、その上に格子状の隔壁を形成する。隔壁で囲まれた部分には着色オイルで満たされており、その上方は水で満たされて透明電極が形成された対向基板と貼り合わされる。この電極間に電圧を印加すると、撥水性絶縁膜の水に対する接触角が低下して撥水性絶縁膜面が親水性に変化し、水がなじむようになる。その結果、水が着色オイルを押しのけ、画素内の着色オイルと水との面積比が変化し画素の明暗が作り出されて表示体として機能する。     In the electrowetting display, a water-repellent (hydrophobic) insulating film is formed on a transparent electrode, and a lattice-like partition is formed thereon. The portion surrounded by the partition walls is filled with colored oil, and the upper portion thereof is filled with water and bonded to a counter substrate on which a transparent electrode is formed. When a voltage is applied between the electrodes, the contact angle of the water-repellent insulating film with respect to water decreases, the surface of the water-repellent insulating film changes to hydrophilic, and water becomes familiar. As a result, water pushes the colored oil, the area ratio between the colored oil and water in the pixel changes, and the brightness of the pixel is created to function as a display body.

従来、この様なエレクトロウェッティング現象を表示装置として使用する場合には、形成された画素内で着色オイルの集合する場所は、それぞれの画素に於いて同一場所である必要があり、それは四角い画素の４コーナーの内のいずれか１つである。そのため、集合する場所を制御する為に、撥水性絶縁膜の下にある駆動用電極の一部を切り欠き、駆動時に掛かる電圧を不均一にして集合場所を規定するが、完全に制御することができない場合がある。   Conventionally, when such an electrowetting phenomenon is used as a display device, the location where the colored oil gathers in the formed pixel needs to be the same in each pixel, which is a square pixel. Any one of the four corners. Therefore, in order to control the gathering location, a part of the driving electrode under the water-repellent insulating film is notched and the voltage applied at the time of driving is specified to define the gathering location. May not be possible.

また、この他の制御方法としては、絶縁膜の一部を画素全体より薄くするものがある（例えば、特許文献１参照）。しかし、画素内に段差が生じてしまい、工程が複雑になり、コストアップの要因にもなる。また、電極を２つの領域に形成し、集合させたいコーナーの対向二辺にＬ字型とそれ以外の部分を形成するものがある（例えば、特許文献２参照）。しかし、駆動素子を１画素に２つ形成しなければならず、工程が複雑になり、歩留まりが低下し、コストアップの要因となる。   As another control method, there is a method in which a part of the insulating film is made thinner than the entire pixel (see, for example, Patent Document 1). However, a step is generated in the pixel, which complicates the process and increases costs. In addition, there is an electrode in which electrodes are formed in two regions, and an L-shape and other portions are formed on two opposite sides of a corner to be assembled (see, for example, Patent Document 2). However, it is necessary to form two drive elements per pixel, which complicates the process, lowers the yield, and increases the cost.

国際公開第０３／０７１３４６号パフレットInternational Publication No. 03/071346 Pufflet 特表２０１０−５０３０１３号公報Special table 2010-503013 gazette

上述したエレクトロウェッティングディスプレイにおいては、次のような問題点があった。   The above-described electrowetting display has the following problems.

・画素に電圧を印加した場合に、画素内の着色オイルの集合する位置はコーナーであるが、どの位置に集合するかは制御できない。   When the voltage is applied to the pixel, the position where the colored oil gathers in the pixel is a corner, but the position where the colored oil gathers cannot be controlled.

・画素毎に着色オイルが移動する位置がバラバラである場合には人間の目に表示が不自然に見えてしまう。   When the position where the colored oil moves for each pixel is different, the display will appear unnatural to the human eye.

・そのため、画素内で着色オイルが移動する場合、常に特定の位置（コーナー）に移動する事が望ましい。   -Therefore, when colored oil moves within a pixel, it is desirable to always move to a specific position (corner).

本発明は、上記のような課題を解決するためになされたものであり、画素に電圧印加した時の着色オイルの集合位置を制御することを可能にするエレクトウェッティングディスプレイを提供することを課題とする。   The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an electwetting display capable of controlling the collection position of colored oil when a voltage is applied to a pixel. And

本発明に係るエレクトウェッティングディスプレイは、基板上に形成された透明電極上に撥水性絶縁膜を形成し、その上に格子状の隔壁を形成し、隔壁で囲まれた部分に着色オイルを満たし、その上方を水で満たして透明電極が形成された対向基板と貼り合わされてなるエレクトロウェッティングディスプレイであって、前記撥水性絶縁膜として、電圧無印加状態では水に対する接触角が同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なる、第１の撥水性絶縁膜と第２の撥水性絶縁膜とを使用し、前記第２の撥水性絶縁膜として、前記第１の撥水性絶縁膜の接触角が印加電圧の上昇により変化開始する前に、接触角の差が所定角度以上変化、もしくは飽和する撥水性絶縁膜を使用することを特徴とする。   In the electwetting display according to the present invention, a water repellent insulating film is formed on a transparent electrode formed on a substrate, a lattice-like partition is formed thereon, and a portion surrounded by the partition is filled with colored oil. An electrowetting display that is bonded to a counter substrate in which the transparent electrode is formed by filling the upper portion thereof with water, and the water-repellent insulating film has the same contact angle with water when no voltage is applied. The first water-repellent insulating film and the second water-repellent insulating film, which have different contact angle characteristics that change with increasing applied voltage, are used as the second water-repellent insulating film. Before the contact angle of the water-repellent insulating film starts to change due to an increase in applied voltage, a water-repellent insulating film in which the difference in contact angle changes or saturates by a predetermined angle or more is used.

本発明によれば、画素に電圧印加した時の着色オイルの集合する方向を制御することができる。   According to the present invention, it is possible to control the direction in which colored oil collects when a voltage is applied to a pixel.

本発明の実施の形態に係るエレクトロウェッティングディスプレイを示す図であって、（ａ）は上面図、（ｂ）は断面図である。It is a figure which shows the electrowetting display which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is sectional drawing. 図１における第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の電圧対接触角の動作特性図である。FIG. 2 is an operation characteristic diagram of voltage versus contact angle of the first water-repellent insulating film 3 and the second water-repellent insulating film 4 in FIG. 1.

本発明に係るエレクトロウェッティングディスプレイは、公知のエレクトロウェッティング効果（電気毛管現象）を利用したエレクトロウェッティングディスプレイであり、撥水性絶縁膜として第１と第２の撥水性絶縁膜を使用する。この２種類の撥水性絶縁膜は、電圧無印加状態では水に対する接触角がほぼ同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なるものであって、第２の撥水性絶縁膜は、第１の撥水性絶縁膜の接触角が電圧により変化開始する前に、所定角度以上の接触角の差を有する、もしくは飽和する撥水性絶縁膜を使用する。そして、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜をＬ字型に形成する。   The electrowetting display according to the present invention is an electrowetting display utilizing a known electrowetting effect (electrocapillarity), and uses the first and second water repellent insulating films as the water repellent insulating film. These two types of water-repellent insulating films have substantially the same contact angle with water when no voltage is applied, but have different contact angle characteristics that change as the applied voltage increases. As the water-based insulating film, a water-repellent insulating film having a contact angle difference of a predetermined angle or more or being saturated before the contact angle of the first water-repellent insulating film starts to change due to voltage is used. Then, a first water-repellent insulating film is formed on the side in contact with the corner where the colored oil is to be gathered, and a second water-repellent insulating film is formed in an L shape on the two sides facing the corner.

以下、具体例について説明する。図１（ａ）、（ｂ）は、本発明の実施の形態に係るエレクトロウェッティングディスプレイの上面図と断面図である。基板１上にＩＴＯ電極２が形成され、ＩＴＯ電極２の上に、着色オイルを集合したいオイル集合コーナーと接する側に第１の撥水性絶縁膜３と形成され、前記オイル集合コーナーに対向する２辺にＬ字型の第２の撥水性絶縁膜４が形成されている。さらに、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の上に、隔壁リブ５が形成されている。ここで、第１の撥水性絶縁膜３は透明フッ素樹脂であるＣＹＴＯＰ（ペルフルオロ（４−ビニルオキシ−１−ブテン）（ＢＶＥ）を環化重合させることにより得られる非結晶フッ素樹脂であって、旭硝子の商品名）で形成され、第２の撥水性絶縁膜４は高誘電率膜＋ＣＹＴＯＰで形成されている。   Hereinafter, specific examples will be described. 1A and 1B are a top view and a cross-sectional view of an electrowetting display according to an embodiment of the present invention. An ITO electrode 2 is formed on the substrate 1, a first water-repellent insulating film 3 is formed on the ITO electrode 2 on the side in contact with the oil collecting corner where the colored oil is to be collected, and 2 facing the oil collecting corner. An L-shaped second water-repellent insulating film 4 is formed on the side. Further, partition ribs 5 are formed on the first water-repellent insulating film 3 and the second water-repellent insulating film 4. Here, the first water repellent insulating film 3 is an amorphous fluororesin obtained by cyclopolymerizing CYTOP (perfluoro (4-vinyloxy-1-butene) (BVE), which is a transparent fluororesin, The second water-repellent insulating film 4 is formed of a high dielectric constant film + CYTOP.

このように、図１に示すように、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜３を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜４をＬ字型に形成することで、印加電圧を徐々に上げていくと、第２の撥水性絶縁膜４側の２辺側が先に接触角が低下し、この２辺側から着色オイルが動くように方向づけられる。さらに、印加電圧が上昇して第１の撥水性絶縁膜３の接触角が変化する電圧に達すると、先の２辺側から着色オイルの後退が起こり、所望するコーナーに向かって着色オイルが集合する。   Thus, as shown in FIG. 1, the first water-repellent insulating film 3 is formed on the side in contact with the corner where the colored oil is to be gathered, and the second water-repellent insulating film 4 is formed on the two sides facing the corner. When the applied voltage is gradually increased by forming the L-shape, the contact angle of the two sides on the second water repellent insulating film 4 side first decreases, and the colored oil moves from the two sides. Oriented to. Further, when the applied voltage rises and reaches a voltage at which the contact angle of the first water-repellent insulating film 3 changes, the colored oil moves backward from the previous two sides, and the colored oil gathers toward the desired corner. To do.

図２は、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の電圧対接触角の動作特性図を示す。図２に示すように、第２の撥水性絶縁膜４の電圧対接触角特性Ａは、第１の撥水性絶縁膜３の電圧対接触角特性Ｂに比較して、印加電圧の上昇につれて、接触角が比較的早く変化することが理解できる。例えば、図２に示す特性図から、印加電圧が４０Ｖである場合、第１の撥水性絶縁膜３の電圧対接触角特性Ｂは接触角が変化しなく、１０６°近辺であるが、第２の撥水性絶縁膜４の電圧対接触角特性Ａの接触角は低下して９２°となる。これにより、着色オイルを集合したいコーナーに対向する２辺側が先に接触角が低下し、この２辺側から着色オイルが動くように方向づけられ、印加電圧がさらに上昇して第１の撥水性絶縁膜３の接触角が変化する電圧、例えば７０Ｖに達すると、先の２辺側から着色オイルの後退が起こり、所望するコーナーに向かって着色オイルが集合することになる。   FIG. 2 shows an operation characteristic diagram of voltage versus contact angle of the first water-repellent insulating film 3 and the second water-repellent insulating film 4. As shown in FIG. 2, the voltage vs. contact angle characteristic A of the second water repellent insulating film 4 is higher than the voltage vs. contact angle characteristic B of the first water repellent insulating film 3 as the applied voltage increases. It can be seen that the contact angle changes relatively quickly. For example, from the characteristic diagram shown in FIG. 2, when the applied voltage is 40 V, the voltage-contact angle characteristic B of the first water-repellent insulating film 3 does not change the contact angle and is around 106 °. The contact angle of the voltage vs. contact angle characteristic A of the water repellent insulating film 4 decreases to 92 °. As a result, the contact angle of the two sides facing the corner where the colored oil is to be gathered first decreases, and the colored oil is directed to move from the two sides, and the applied voltage is further increased to increase the first water repellent insulation. When the voltage at which the contact angle of the film 3 changes, for example, 70V, the colored oil moves backward from the two sides, and the colored oil collects toward a desired corner.

したがって、本発明の実施の形態によれば、撥水性絶縁膜として、電圧無印加状態では水に対する接触角が同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なる、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４とを使用し、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜３を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜４をＬ字型に形成することで、電圧印加した時の着色オイルの集合する方向を制御することができる。   Therefore, according to the embodiment of the present invention, the water-repellent insulating film has the same contact angle with water when no voltage is applied, but the characteristics of the contact angle that changes as the applied voltage increases are different. The first water-repellent insulating film 3 and the second water-repellent insulating film 4 are used, the first water-repellent insulating film 3 is formed on the side in contact with the corner where the colored oil is to be collected, and two sides facing the corner In addition, by forming the second water repellent insulating film 4 in an L shape, the direction in which the colored oil collects when a voltage is applied can be controlled.

１ 基板、２ ＩＴＯ電極、３ 第１の撥水性絶縁膜、４ 第２の撥水性絶縁膜、５ 隔壁リブ。   1 substrate, 2 ITO electrode, 3 first water-repellent insulating film, 4 second water-repellent insulating film, 5 partition rib.

本発明は、エレクトロウェッティング現象を用いたエレクトロウェッティングディスプレイに関する。 The present invention relates to electrospray wetting display using an electrowetting phenomenon.

エレクトロウェッティングディスプレイは、透明電極上に撥水性（疎水性）の絶縁膜を形成し、その上に格子状の隔壁を形成する。隔壁で囲まれた部分には着色オイルで満たされており、その上方は水で満たされて透明電極が形成された対向基板と貼り合わされる。この電極間に電圧を印加すると、撥水性絶縁膜の水に対する接触角が低下して撥水性絶縁膜面が親水性に変化し、水がなじむようになる。その結果、水が着色オイルを押しのけ、画素内の着色オイルと水との面積比が変化し画素の明暗が作り出されて表示体として機能する。     In the electrowetting display, a water-repellent (hydrophobic) insulating film is formed on a transparent electrode, and a lattice-like partition is formed thereon. The portion surrounded by the partition walls is filled with colored oil, and the upper portion thereof is filled with water and bonded to a counter substrate on which a transparent electrode is formed. When a voltage is applied between the electrodes, the contact angle of the water-repellent insulating film with respect to water decreases, the surface of the water-repellent insulating film changes to hydrophilic, and water becomes familiar. As a result, water pushes the colored oil, the area ratio between the colored oil and water in the pixel changes, and the brightness of the pixel is created to function as a display body.

従来、この様なエレクトロウェッティング現象を表示装置として使用する場合には、形成された画素内で着色オイルの集合する場所は、それぞれの画素に於いて同一場所である必要があり、それは四角い画素の４コーナーの内のいずれか１つである。そのため、集合する場所を制御する為に、撥水性絶縁膜の下にある駆動用電極の一部を切り欠き、駆動時に掛かる電圧を不均一にして集合場所を規定するが、完全に制御することができない場合がある。   Conventionally, when such an electrowetting phenomenon is used as a display device, the location where the colored oil gathers in the formed pixel needs to be the same in each pixel, which is a square pixel. Any one of the four corners. Therefore, in order to control the gathering location, a part of the driving electrode under the water-repellent insulating film is notched and the voltage applied at the time of driving is specified to define the gathering location. May not be possible.

また、この他の制御方法としては、絶縁膜の一部を画素全体より薄くするものがある（例えば、特許文献１参照）。しかし、画素内に段差が生じてしまい、工程が複雑になり、コストアップの要因にもなる。また、電極を２つの領域に形成し、集合させたいコーナーの対向二辺にＬ字型とそれ以外の部分を形成するものがある（例えば、特許文献２参照）。しかし、駆動素子を１画素に２つ形成しなければならず、工程が複雑になり、歩留まりが低下し、コストアップの要因となる。   As another control method, there is a method in which a part of the insulating film is made thinner than the entire pixel (see, for example, Patent Document 1). However, a step is generated in the pixel, which complicates the process and increases costs. In addition, there is an electrode in which electrodes are formed in two regions, and an L-shape and other portions are formed on two opposite sides of a corner to be assembled (see, for example, Patent Document 2). However, it is necessary to form two drive elements per pixel, which complicates the process, lowers the yield, and increases the cost.

国際公開第０３／０７１３４６号パンフレットInternational Publication No. 03/071346 Pamphlet 特表２０１０−５０３０１３号公報Special table 2010-503013 gazette

上述したエレクトロウェッティングディスプレイにおいては、次のような問題点があった。   The above-described electrowetting display has the following problems.

・画素に電圧を印加した場合に、画素内の着色オイルの集合する位置はコーナーであるが、どの位置に集合するかは制御できない。   When the voltage is applied to the pixel, the position where the colored oil gathers in the pixel is a corner, but the position where the colored oil gathers cannot be controlled.

・画素毎に着色オイルが移動する位置がバラバラである場合には人間の目に表示が不自然に見えてしまう。   When the position where the colored oil moves for each pixel is different, the display will appear unnatural to the human eye.

・そのため、画素内で着色オイルが移動する場合、常に特定の位置（コーナー）に移動する事が望ましい。   -Therefore, when colored oil moves within a pixel, it is desirable to always move to a specific position (corner).

本発明は、上記のような課題を解決するためになされたものであり、画素に電圧印加した時の着色オイルの集合位置を制御することを可能にするエレクトロトウェッティングディスプレイを提供することを課題とする。 The present invention has been made to solve the above problems, providing electrospray preparative wetting display which makes it possible to control the set position of the colored oil upon the voltage applied to the pixel Is an issue.

本発明に係るエレクトロトウェッティングディスプレイは、基板上に形成された透明電極上に撥水性絶縁膜を形成し、その上に格子状の隔壁を形成し、隔壁で囲まれた部分に着色オイルを満たし、その上方を水で満たして透明電極が形成された対向基板と貼り合わされてなるエレクトロウェッティングディスプレイであって、前記撥水性絶縁膜として、電圧無印加状態では水に対する接触角が同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なる、第１の撥水性絶縁膜と第２の撥水性絶縁膜とを使用し、前記第２の撥水性絶縁膜として、前記第１の撥水性絶縁膜の接触角が印加電圧の上昇により変化開始する前に、接触角の差が所定角度以上変化、もしくは飽和する撥水性絶縁膜を使用することを特徴とする。 Electrospray DOO wetting display of the present invention, water-repellent insulating film is formed on the transparent electrode formed on a substrate to form a lattice-like barrier rib thereon colored oil portion surrounded by the partition wall An electrowetting display that is bonded to a counter substrate on which a transparent electrode is formed by filling the upper surface with water, and the water-repellent insulating film has the same contact angle with water when no voltage is applied. However, the first water-repellent insulating film and the second water-repellent insulating film, which have different contact angle characteristics that change as the applied voltage increases, are used as the second water-repellent insulating film. Before the contact angle of the first water-repellent insulating film starts to change due to an increase in applied voltage, a water-repellent insulating film in which the difference in contact angle changes or saturates by a predetermined angle or more is used.

本発明によれば、画素に電圧印加した時の着色オイルの集合する方向を制御することができる。   According to the present invention, it is possible to control the direction in which colored oil collects when a voltage is applied to a pixel.

本発明の実施の形態に係るエレクトロウェッティングディスプレイを示す図であって、（ａ）は上面図、（ｂ）は断面図である。It is a figure which shows the electrowetting display which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is sectional drawing. 図１における第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の電圧対接触角の動作特性図である。FIG. 2 is an operation characteristic diagram of voltage versus contact angle of the first water-repellent insulating film 3 and the second water-repellent insulating film 4 in FIG. 1.

本発明に係るエレクトロウェッティングディスプレイは、公知のエレクトロウェッティング効果（電気毛管現象）を利用したエレクトロウェッティングディスプレイであり、撥水性絶縁膜として第１と第２の撥水性絶縁膜を使用する。この２種類の撥水性絶縁膜は、電圧無印加状態では水に対する接触角がほぼ同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なるものであって、第２の撥水性絶縁膜は、第１の撥水性絶縁膜の接触角が電圧により変化開始する前に、所定角度以上の接触角の差を有する、もしくは飽和する撥水性絶縁膜を使用する。そして、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜をＬ字型に形成する。   The electrowetting display according to the present invention is an electrowetting display utilizing a known electrowetting effect (electrocapillarity), and uses the first and second water repellent insulating films as the water repellent insulating film. These two types of water-repellent insulating films have substantially the same contact angle with water when no voltage is applied, but have different contact angle characteristics that change as the applied voltage increases. As the water-based insulating film, a water-repellent insulating film having a contact angle difference of a predetermined angle or more or being saturated before the contact angle of the first water-repellent insulating film starts to change due to voltage is used. Then, a first water-repellent insulating film is formed on the side in contact with the corner where the colored oil is to be gathered, and a second water-repellent insulating film is formed in an L shape on the two sides facing the corner.

以下、具体例について説明する。図１（ａ）、（ｂ）は、本発明の実施の形態に係るエレクトロウェッティングディスプレイの上面図と断面図である。基板１上にＩＴＯ電極２が形成され、ＩＴＯ電極２の上に、着色オイルを集合したいオイル集合コーナーと接する側に第１の撥水性絶縁膜３と形成され、前記オイル集合コーナーに対向する２辺にＬ字型の第２の撥水性絶縁膜４が形成されている。さらに、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の上に、隔壁リブ５が形成されている。ここで、第１の撥水性絶縁膜３は透明フッ素樹脂であるＣＹＴＯＰ（ペルフルオロ（４−ビニルオキシ−１−ブテン）（ＢＶＥ）を環化重合させることにより得られる非結晶フッ素樹脂であって、旭硝子の商品名）で形成され、第２の撥水性絶縁膜４は高誘電率膜＋ＣＹＴＯＰで形成されている。   Hereinafter, specific examples will be described. 1A and 1B are a top view and a cross-sectional view of an electrowetting display according to an embodiment of the present invention. An ITO electrode 2 is formed on the substrate 1, a first water-repellent insulating film 3 is formed on the ITO electrode 2 on the side in contact with the oil collecting corner where the colored oil is to be collected, and 2 facing the oil collecting corner. An L-shaped second water-repellent insulating film 4 is formed on the side. Further, partition ribs 5 are formed on the first water-repellent insulating film 3 and the second water-repellent insulating film 4. Here, the first water repellent insulating film 3 is an amorphous fluororesin obtained by cyclopolymerizing CYTOP (perfluoro (4-vinyloxy-1-butene) (BVE), which is a transparent fluororesin, The second water-repellent insulating film 4 is formed of a high dielectric constant film + CYTOP.

このように、図１に示すように、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜３を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜４をＬ字型に形成することで、印加電圧を徐々に上げていくと、第２の撥水性絶縁膜４側の２辺側が先に接触角が低下し、この２辺側から着色オイルが動くように方向づけられる。さらに、印加電圧が上昇して第１の撥水性絶縁膜３の接触角が変化する電圧に達すると、先の２辺側から着色オイルの後退が起こり、所望するコーナーに向かって着色オイルが集合する。   Thus, as shown in FIG. 1, the first water-repellent insulating film 3 is formed on the side in contact with the corner where the colored oil is to be gathered, and the second water-repellent insulating film 4 is formed on the two sides facing the corner. When the applied voltage is gradually increased by forming the L-shape, the contact angle of the two sides on the second water repellent insulating film 4 side first decreases, and the colored oil moves from the two sides. Oriented to. Further, when the applied voltage rises and reaches a voltage at which the contact angle of the first water-repellent insulating film 3 changes, the colored oil moves backward from the previous two sides, and the colored oil gathers toward the desired corner. To do.

図２は、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４の電圧対接触角の動作特性図を示す。図２に示すように、第２の撥水性絶縁膜４の電圧対接触角特性Ａは、第１の撥水性絶縁膜３の電圧対接触角特性Ｂに比較して、印加電圧の上昇につれて、接触角が比較的早く変化することが理解できる。例えば、図２に示す特性図から、印加電圧が４０Ｖである場合、第１の撥水性絶縁膜３の電圧対接触角特性Ｂは接触角が変化しなく、１０６°近辺であるが、第２の撥水性絶縁膜４の電圧対接触角特性Ａの接触角は低下して９２°となる。これにより、着色オイルを集合したいコーナーに対向する２辺側が先に接触角が低下し、この２辺側から着色オイルが動くように方向づけられ、印加電圧がさらに上昇して第１の撥水性絶縁膜３の接触角が変化する電圧、例えば７０Ｖに達すると、先の２辺側から着色オイルの後退が起こり、所望するコーナーに向かって着色オイルが集合することになる。   FIG. 2 shows an operation characteristic diagram of voltage versus contact angle of the first water-repellent insulating film 3 and the second water-repellent insulating film 4. As shown in FIG. 2, the voltage vs. contact angle characteristic A of the second water repellent insulating film 4 is higher than the voltage vs. contact angle characteristic B of the first water repellent insulating film 3 as the applied voltage increases. It can be seen that the contact angle changes relatively quickly. For example, from the characteristic diagram shown in FIG. 2, when the applied voltage is 40 V, the voltage-contact angle characteristic B of the first water-repellent insulating film 3 does not change the contact angle and is around 106 °. The contact angle of the voltage vs. contact angle characteristic A of the water repellent insulating film 4 decreases to 92 °. As a result, the contact angle of the two sides facing the corner where the colored oil is to be gathered first decreases, and the colored oil is directed to move from the two sides, and the applied voltage is further increased to increase the first water repellent insulation. When the voltage at which the contact angle of the film 3 changes, for example, 70V, the colored oil moves backward from the two sides, and the colored oil collects toward a desired corner.

したがって、本発明の実施の形態によれば、撥水性絶縁膜として、電圧無印加状態では水に対する接触角が同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なる、第１の撥水性絶縁膜３と第２の撥水性絶縁膜４とを使用し、着色オイルを集合したいコーナーと接する側に第１の撥水性絶縁膜３を形成し、そのコーナーに対向する２辺に第２の撥水性絶縁膜４をＬ字型に形成することで、電圧印加した時の着色オイルの集合する方向を制御することができる。   Therefore, according to the embodiment of the present invention, the water-repellent insulating film has the same contact angle with water when no voltage is applied, but the characteristics of the contact angle that changes as the applied voltage increases are different. The first water-repellent insulating film 3 and the second water-repellent insulating film 4 are used, the first water-repellent insulating film 3 is formed on the side in contact with the corner where the colored oil is to be collected, and two sides facing the corner In addition, by forming the second water repellent insulating film 4 in an L shape, the direction in which the colored oil collects when a voltage is applied can be controlled.

１ 基板、２ ＩＴＯ電極、３ 第１の撥水性絶縁膜、４ 第２の撥水性絶縁膜、５ 隔壁リブ。   1 substrate, 2 ITO electrode, 3 first water-repellent insulating film, 4 second water-repellent insulating film, 5 partition rib.

Claims (2)

基板上に形成された透明電極上に撥水性絶縁膜を形成し、その上に格子状の隔壁を形成し、隔壁で囲まれた部分に着色オイルを満たし、その上方を水で満たして透明電極が形成された対向基板と貼り合わされてなるエレクトロウェッティングディスプレイであって、
前記撥水性絶縁膜として、電圧無印加状態では水に対する接触角が同等であるが、印加電圧の上昇に伴って変化する接触角の特性が異なる、第１の撥水性絶縁膜と第２の撥水性絶縁膜とを使用し、
前記第２の撥水性絶縁膜として、前記第１の撥水性絶縁膜の接触角が印加電圧の上昇により変化開始する前に、接触角の差が所定角度以上の変化、もしくは飽和する撥水性絶縁膜を使用する
ことを特徴とするエレクトロウェッティングディスプレイ。 A transparent electrode is formed by forming a water-repellent insulating film on a transparent electrode formed on a substrate, forming a grid-like partition wall thereon, filling a portion surrounded by the partition wall with colored oil, and filling the upper portion with water. Is an electrowetting display bonded to a counter substrate on which is formed,
As the water-repellent insulating film, the first water-repellent insulating film and the second water-repellent insulating film have the same contact angle with water when no voltage is applied, but have different contact angle characteristics that change as the applied voltage increases. Using water-based insulation film,
As the second water-repellent insulating film, before the contact angle of the first water-repellent insulating film starts to change due to an increase in applied voltage, the difference in the contact angle changes more than a predetermined angle or becomes saturated. An electrowetting display characterized by using a membrane. 請求項１に記載のエレクトロウェッティングディスプレイにおいて、
前記第１の撥水性絶縁膜は、前記着色オイルを集合したいコーナーと接する側に形成され、
前記第２の撥水性絶縁膜は、前記コーナーに対向する２辺にＬ字型に形成される
ことを特徴とするエレクトロウェッティングディスプレイ。 The electrowetting display according to claim 1,
The first water repellent insulating film is formed on a side in contact with a corner where the colored oil is to be collected,
The electro-wetting display, wherein the second water-repellent insulating film is formed in an L shape on two sides facing the corner.
JP2011235566A 2011-10-27 2011-10-27 Electrowetting display Pending JP2013092701A (en)

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CN105425385A (en) * 2015-11-26 2016-03-23 华南师范大学 Electrowetting display device for controlling ink motion and preparation method thereof
WO2016119581A1 (en) * 2015-01-27 2016-08-04 深圳市国华光电研究院 Method for improving electrowetting device encapsulation performance and electrowetting device
US9753274B2 (en) 2014-07-31 2017-09-05 Jsr Corporation Display element, photosensitive composition and electrowetting display
US9784965B2 (en) 2014-03-04 2017-10-10 Jsr Corporation Display element, photosensitive composition and electrowetting display
CN110609384A (en) * 2019-08-30 2019-12-24 华南师范大学 Device capable of controlling ink movement based on electrowetting technology and preparation method thereof
WO2020042656A1 (en) * 2018-08-31 2020-03-05 京东方科技集团股份有限公司 Pixel definition structure, display panel and preparation method therefor, and display apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9784965B2 (en) 2014-03-04 2017-10-10 Jsr Corporation Display element, photosensitive composition and electrowetting display
US9753274B2 (en) 2014-07-31 2017-09-05 Jsr Corporation Display element, photosensitive composition and electrowetting display
WO2016119581A1 (en) * 2015-01-27 2016-08-04 深圳市国华光电研究院 Method for improving electrowetting device encapsulation performance and electrowetting device
CN105425385A (en) * 2015-11-26 2016-03-23 华南师范大学 Electrowetting display device for controlling ink motion and preparation method thereof
WO2020042656A1 (en) * 2018-08-31 2020-03-05 京东方科技集团股份有限公司 Pixel definition structure, display panel and preparation method therefor, and display apparatus
US10964776B2 (en) 2018-08-31 2021-03-30 Boe Technology Group Co., Ltd. Pixel defining structure, display panel, method of manufacturing the same and display device
CN110609384A (en) * 2019-08-30 2019-12-24 华南师范大学 Device capable of controlling ink movement based on electrowetting technology and preparation method thereof
CN110609384B (en) * 2019-08-30 2024-01-16 华南师范大学 Device capable of controlling ink movement based on electrowetting technology and preparation method thereof

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