JP3746333B2 - Liquid crystal display - Google Patents

Liquid crystal display Download PDF

Info

Publication number
JP3746333B2
JP3746333B2 JP20624396A JP20624396A JP3746333B2 JP 3746333 B2 JP3746333 B2 JP 3746333B2 JP 20624396 A JP20624396 A JP 20624396A JP 20624396 A JP20624396 A JP 20624396A JP 3746333 B2 JP3746333 B2 JP 3746333B2
Authority
JP
Japan
Prior art keywords
electrode
liquid crystal
substrate
common electrode
display
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP20624396A
Other languages
Japanese (ja)
Other versions
JPH1048652A (en
Inventor
昌也 水沼
文雄 松川
顕 津村
伸 田畑
晃 玉谷
康裕 森井
雅之 藤井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP20624396A priority Critical patent/JP3746333B2/en
Publication of JPH1048652A publication Critical patent/JPH1048652A/en
Application granted granted Critical
Publication of JP3746333B2 publication Critical patent/JP3746333B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • 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
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G02F1/133707—Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
    • 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
    • G02F1/134381—Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
    • 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
    • G02F1/137—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/13706—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering the liquid crystal having positive dielectric anisotropy

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Liquid Crystal (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)

Description

【０００１】
【発明の属する技術分野】
この発明は、横方向電界方式の液晶表示装置、特にその視覚特性の向上および駆動電圧の低下に関するものである。
【０００２】
【従来の技術】
液晶表示装置は、薄く、低電圧駆動が可能であるので、腕時計、電卓等の表示装置として広く使われている。特にＴＦＴ（薄膜トランジスタ）等のアクティブスイッチ素子を組み込んだＴＮ型液晶表示装置は、ＣＲＴ並みの表示特性を発揮するので、ワードプロセッサー、パーソナルコンピュータのディスプレイやテレビ等にも用いられるようになってきている。しかしながら、ＴＮ型液晶表示装置においては、視野角が中間調表示において狭く、表示画面の周縁部と中央部では色またはコントラストに大きな差が出てしまう。この現象は、ＴＮ型液晶表示方式がｐ型のネマチック液晶材料に電界を印加して電界方向に沿って液晶分子を立たせることにより旋光性を制御する方式であり、液晶分子の立ち上がり方向が決まっているために起きる。従って、ＴＮ型液晶表示装置においては、視野角の問題は根本的に解決できない。
【０００３】
この問題を解決するために、ＴＮ型液晶表示方式のように液晶分子を配向させた状態で電界を横方向、すなわち基板に水平な方向に印加することにより液晶分子を回転させ、旋光性もしくは複屈折性を制御する横方向電界方式が提案されている。この横方向電界方式では、基板上にインターディジタル形状の電極を形成し、この電極間に電圧を印加し、基板に水平方向の電界を形成するもので、液晶材料としては一般的にｎ型のネマチック液晶が用いられている。
【０００４】
【発明が解決しようとする課題】
以上のように、従来の横方向電界方式の液晶表示装置においては、一般に誘電異方性が小さなｎ型のネマチック液晶を用いていたので、駆動電圧が高くなるという問題があった。また、図５は従来の横方向電界方式の液晶表示装置にｐ型のネマチック液晶を用いた場合の液晶の配向状態を説明する部分断面図である。図において、１は液晶分子、２は表示電極、３は共通電極であり、表示電極２と共通電極３は共にインターディジタル形状の電極である。５は配向膜、６は絶縁膜、７はガラス基板、８は偏光板、９は電気力線をそれぞれ示す。図５に示ように、従来の横電界方式の液晶表示装置においてｐ型のネマチック液晶１を用いた場合、インターディジタル形状の表示電極２および共通電極３間に電圧を印加した時、電極間で電気力線９が山なりに歪みを生じ、液晶分子１は電界方向に沿って配列しようとするため、電極間の中央付近で液晶配向のぶつかりが生じ、ディスクリネーションが発生する。ディスクリネーションの発生／消失にはヒステリシスを伴うため、残像が発生し、表示品位が低下するという問題点があった。
【０００５】
本発明は、上記のような問題点を解消するためになされたもので、低電圧駆動が可能であり、残像の少ない横方向電界方式の液晶表示装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
この発明に係わる液晶表示装置は、基板上に平行に配置された複数本の電極よりなる表示電極と、同じ基板上に、表示電極と平行且つ交互に配置された複数本の電極よりなる共通電極と、上記基板に対向する基板上に配置された第３の電極、およびこれら２枚の基板間に配向膜を介して配置された液晶を備え、第３の電極は、その隣接する各電極が、それらの間に他の電極を挟むことなく、少なくともそれらの一部が共通電極の投影面上に位置し、その幅が対向する共通電極の各電極の幅の１０％よりも大きく、且つ共通電極の各電極に隣接する表示電極の各電極の投影面上に及ばない範囲で形成され、表示電極および共通電極間に電圧を印加するとともに第３の電極の電位を共通電極と同一電位に制御し、基板面にほぼ水平方向に電界を発生させ液晶を面内応答させることにより光学特性を制御するものである。
【０００７】
また、基板上に平行に配置された複数本の電極よりなる表示電極と、同じ基板上に、表示電極と平行且つ交互に配置された複数本の電極よりなる共通電極と、上記基板に対向する第２の基板上に形成され、表示電極および共通電極の投影面でない領域に配置された第３の電極と、これらの２枚の基板間に配向膜を介して配置された液晶を備え、表示電極および共通電極間に電圧を印加するとともに第３の電極の電位を表示電極と共通電極との間の電位差のほぼ１／２に相当する電位に制御し、基板面にほぼ水平方向に電界を発生させ液晶を面内応答させることにより光学特性を制御するものである。
さらに、液晶は、正の誘電異方性を有するものである。
【０００８】
【発明の実施の形態】
実施の形態１．
図１は、本発明の実施の形態１である横方向電界方式の液晶表示装置の構成を示す部分断面図および平面図である。図１−ａは、表面にインターディジタル形状の電極を有する基板と対向基板より構成された本実施の形態による液晶表示装置を示す部分断面図、図１−ｂは、インターディジタル形状の電極の構造を示す平面図である。図において、１は液晶分子、２は表示電極、３は共通電極であり、表示電極２と共通電極３は共にインターディジタル形状である。さらに、４は表示電極２および共通電極３が形成された基板に対向する基板に配置された第３の電極、５は配向膜、６は絶縁膜、７はガラス基板、８は偏光板をそれぞれ示す。本実施の形態における第３の電極４は、その隣接する各電極が、それらの間に他の電極を挟むことなく、少なくともそれらの一部が共通電極３の投影面上に位 置している。
【０００９】
本実施の形態による液晶表示装置は、一対の基板の間に配向膜５を介して液晶１が配置され、一方の基板上に互いに絶縁されて形成されたインターディジタル形状の電極、表示電極２および共通電極３間に電圧を印加し、基板面にほぼ水平方向に電界を発生させ、液晶分子１を面内方向に回転させることにより光学特性を制御する面内応答型の液晶表示装置であって、インターディジタル形状の電極が形成された基板に対向する基板上に第３の電極４を設け、第３の電極４の電位を制御することにより横方向電界を効率的に液晶分子１に印加し、低い駆動電圧で視野角特性の優れた液晶表示装置を得るものである。第３の電極４を設けていない従来の横電界方式の液晶表示装置においてｐ型のネマチック液晶１を用いた場合、図５に示すように、表示電極２および共通電極３間に電圧を印加した時、電極間で電気力線９が山なりに歪みを生じ、液晶分子１は電界方向に沿って配列しようとするため、電極間の中央付近で液晶配向のぶつかりが生じ、ディスクリネーションが発生する。ディスクリネーションの発生／消失にはヒステリシスを伴うため、残像が発生し、表示品位が低下するという問題点があった。本発明によれば、第３の電極４を設けることにより、電界を基板面により水平に形成できるため、液晶配向のぶつかりが生じず、ディスクリネーションが発生しない、すなわち残像のない液晶表示装置が得られる。なお、本実施の形態では、第３の電極４は少なくともその一部が対向する基板上に形成されている共通電極３の投影面上に形成され、この共通電極３と同一電位に制御されている。
【００１０】
第３の電極４を対向基板上に形成し、共通電極３の電位と同一電位に制御する場合、第３の電極４の幅は、対向する共通電極３の各電極の幅の１０％よりも大きく、且つ対向する共通電極３の各電極に隣接する表示電極２の各電極の投影面上に及ばない範囲まで形成することができる。第３の電極４の幅が共通電極３の幅の１０％より狭い場合、第３の電極４を設ける効果が小さく、隣接する表示電極２の投影面上にかかると液晶分子１に横方向電界が印加されない。ただし、第３の電極４は対向する共通電極３すべての投影面上に形成する必要はなく、例えば対向基板上に設けた導電性材料で形成されたブラックマトリクスを第３の電極４として用いても良い。
【００１１】
さらに、インターディジタル電極の形状は、図１に示すように同一平面上に複数本の表示電極２および共通電極３が交互に入り組んだ形状に限るものではなく、例えば図２に示すように絶縁膜６を挟んで表示電極２および共通電極３を形成する構造でも良い。図２において６６は絶縁膜を示し、同一符号は同一あるいは相当部分を示す。ただし、電極構造は液晶分子１に横方向電界が印加できる形状であれば良く、ここに示した形状に限定されるものではない。また、本実施の形態において、マトリクス駆動用の配線を一対の基板上にすべて設けるためには、配線同士を絶縁する必要がある。このため、少なくとも２つのインターディジタル電極すなわち表示電極２と共通電極３の間を絶縁して設ける方法としては、ＳｉＯＸやＳｉＮＸ等の無機材料または有機材料からなる絶縁層を基板上に設け、その上または側面にインターディジタル電極を設ければよい。
【００１２】
本発明の液晶表示装置において用いられる液晶材料としては、ネマチック液晶材料を用いることができる。液晶材料のタイプとしてはｐ型のネマチック液晶およびｎ型のネマチック液晶のいずれの液晶材料も用いることができるが、誘電異方性の大きな液晶材料が得られやすく、低電圧駆動に有効あるｐ型のネマチック液晶材料を用いることが好ましい。基板材料としては、ガラス、石英、シリコン等を用いることができるが、透過型および反射型の液晶表示装置として用いるために、少なくとも一方は透明の基板でなければならない。また、配向膜材料はポリイミド、ＰＶＡ等の有機物あるいはＳｉＯＸなど無機物の斜方蒸着膜などを用いることができる。液晶材料と配向膜を組み合わせたとき、プレチルト角が５度を超えると視覚特性に歪みを生じるので、プレチルト角は５度以下であることが好ましい。さらに、電極材料としては、Ａｌ、Ｃｒ、Ｔｉ、Ｃｕ、Ｍｏ、Ｔａ、Ｉｎ、ＳｎＯ２ 、ＩＴＯ等の導電性金属、金属酸化物、導電性高分子等を用いることができる。
【００１３】
以上のように、本実施の形態によれば、インターディジタル形状の表示電極２および共通電極３が形成された基板に対向する基板上の、共通電極３の投影面上に第３の電極４を設け、第３の電極４の電位を共通電極３と同電位に制御することにより、横方向電界を効率的に液晶分子１に印加することができるので、低い駆動電圧で視野角特性の優れた液晶表示装置を得ることができる。
【００１４】
実施の形態２．
図３は、本発明の実施の形態２である横方向電界方式の液晶表示装置の構成を示す部分断面図である。図中、同一、相当部分には同一符号を付し説明を省略する。本実施の形態では、インターディジタル形状の表示電極２および共通電極３が形成された基板に対向する基板上の、表示電極２および共通電極３の投影面でない領域に第３の電極４を設け、この第３の電極４の電位をインターディジタル形状の電極の電位とは独立に制御することにより、横方向電界を効率的に液晶分子１に印加し、低い駆動電圧で視野角特性の優れた液晶表示装置を得るものである。
なお、本実施の形態のように、第３の電極４をインターディジタル電極の形成されていない部分の投影面上に形成する場合、インターディジタル電極すなわち表示電極２および共通電極３もしくは第３の電極４のうち少なくとも１つの電極材料は、透明電極材料でなければならない。さらに、液晶分子１は主に表示電極２と共通電極３の間で回転するので、第３の電極４は透明電極材料で構成されていることが望ましい。
【００１５】
本実施の形態による液晶表示装置に用いられる液晶材料、基板材料および配向膜材料、電極材料は実施の形態１で示すものと同様の材料を用いることができる。さらに、インターディジタル電極の形状は、表示電極２と共通電極３を同一平面上に形成する図３に示す構造に限定するものではなく、絶縁膜を挟んだ多層構造等でもよく、液晶分子１に横方向電界が印加できる形状であればよい。
【００１６】
【実施例】
以下に、本発明による液晶表示装置の実施例について説明する。はじめに作成した液晶表示装置の測定方法について述べる。駆動電圧は表示電極２と共通電極３の間に電圧を印加し、その振幅を増加させた時に最大透過率を与える電圧とした。第３の電極４の電位は個々の実施例に記載した通りである。印加を上昇させる時と下降させる時の電圧−透過率特性に差が０．１Ｖ以上生じたとき、残像の原因となるヒステリシス有りとした。視野角はコントラスト１０：１を与える角度とした。この時インターディジタル電極の長手方向を上下、これと直交する方向を左右とした。
実施例１．
以下に、本発明の実施例１である液晶表示装置の製造方法について説明する。
また、実施例１〜３および比較例による液晶表示装置の評価結果を表１に示す。
【００１７】
【表１】

Figure 0003746333
【００１８】
一枚のガラス基板上にＩＴＯ膜を形成し、ポジ型感光性レジストを用いて、図１−ｂに示すようなインターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＩＴＯ膜を形成し、対向する共通電極３の投影面上に５本に１本の割合で第３の電極４を有する基板を作成する。第３の電極の幅は共通電極と同じである。さらに、配向膜５を形成し、ラビングを行い、得られた基板を５μｍのスペーサを用いて、ラビング方向がアンチパラレルになるように重ねあわせ、周辺部をシールして液晶セルを作成する。ここで得られた液晶セルの空隙に誘電異方性５.７、屈折率異方性０.０９０のｐ型ネマチック液晶材料を注入する。次いで表示モードがノーマリーブラックとなるように偏光板を張り付け、本実施例の液晶表示装置を得る。本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。
【００１９】
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記の測定法にて評価した結果、ディスクリネーションの発生が見られず、表１に示すような良好な表示特性が得られた。
【００２０】
比較例．
上記実施例１の比較例として、対向基板に第３の電極４を形成せず、それ以外は実施例１と同様の構成および材料で形成した液晶表示装置について同様の測定を行い評価したところ、ディスクリネーションが発生し、ヒステリシスが観察された。また、最大透過率が得られる電圧が実施例１に比べ高くなった。
【００２１】
実施例２．
以下に、本発明の実施例２である液晶表示装置の製造方法について説明する。
一枚のガラス基板上にＣｒ膜を形成し、ポジ型感光性レジストを用いて、図１−ｂに示すようなインターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＣｒ膜を形成し、対向する共通電極３の投影面上に５本に１本の割合で第３の電極４を有する基板を作成する。第３の電極の幅は共通電極と同じである。これ以降の工程は、実施例１と同様に行う。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記実施例１と同様の測定法にて評価した結果、ディスクリネーションの発生が見られず、表１に示すような良好な表示特性が得られた。
【００２２】
実施例３．
以下に、本発明の実施例３である液晶表示装置の製造方法について説明する。
一枚のガラス基板上にＩＴＯ膜を形成し、ポジ型感光性レジストを用いて、図１−ｂに示すようなインターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＣｒ膜を形成し、対向する共通電極３の投影面上の５本に１本の割合で第３の電極４を有する基板を作成する。第３の電極の幅は共通電極と同じである。これ以降の工程は、実施例１と同様に行う。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記実施例１と同様の測定法にて評価した結果、表１に示すような良好な表示特性が得られた。
【００２３】
実施例４．
以下に、本発明の実施例４である液晶表示装置の製造方法について説明する。また、実施例４〜６による液晶表示装置の評価結果を表２に示す。
【００２４】
【表２】
Figure 0003746333
【００２５】
一枚のガラス基板上にＣｒ膜を形成し、ポジ型感光性レジストを用いて、インターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＣｒ膜を形成し、対向する共通電極３の投影面上に、共通電極３の幅に対して５０％の幅を持つ第３の電極４を有する基板を作成する。さらに、配向膜５を形成し、ラビングを行い、得られた基板を５μmのスペーサを用いて、ラビング方向がアンチパラレルになるように重ねあわせ、周辺部をシールして図４に示すような断面構造の液晶セルを作成する。ここで得られた液晶セルの空隙に誘電異方性５.７、屈折率異方性０.０９０のｐ型ネマチック液晶材料を注入する。次いで表示モードがノーマリーブラックとなるように偏光板を張り付け、本実施例の液晶表示装置を得る。本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記実施例１と同様の測定法にて評価した結果、表２に示すような良好な表示特性が得られた。
【００２６】
実施例５．
以下に、本発明の実施例５である液晶表示装置の製造方法について説明する。
一枚のガラス基板上にＣｒ膜を形成し、ポジ型感光性レジストを用いて、インターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＣｒ膜を形成し、対向する共通電極３の投影面上に、共通電極３の幅に対して１００％の幅を持つ第３の電極４を有する基板を作成する。これ以降の工程は、実施例４と同様に行う。なお、本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記実施例１と同様の測定法にて評価した結果、表２に示すような良好な表示特性が得られた。
【００２７】
実施例６．
以下に、本発明の実施例６である液晶表示装置の製造方法について説明する。
一枚のガラス基板上にＣｒ膜を形成し、ポジ型感光性レジストを用いて、インターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＣｒ膜を形成し、対向する共通電極３の投影面上に、共通電極３の幅に対して１５０％の幅を持つ第３の電極４を有する基板を作成する。これ以降の工程は、実施例４と同様に行う。なお、本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を共通電極３の電位と同じ電位に制御して、上記実施例１と同様の測定法にて評価した結果、表２に示すような良好な表示特性が得られた。
【００２８】
実施例７．
以下に、本発明の実施例７である液晶表示装置の製造方法について説明する。また、実施例７〜１０による液晶表示装置の評価結果を表３に示す。
【００２９】
【表３】
Figure 0003746333
【００３０】
一枚のガラス基板上にＣｒ膜を形成し、ポジ型感光性レジストを用いて、インターディジタル形状の表示電極２および共通電極３を作成する。次に、基板上に配向膜５を形成した後、インターディジタル電極の長手方向と垂直な方向から１０度ずれた方向にラビング処理を行う。対向する基板として、ガラス基板にＩＴＯ膜を形成し、対向する基板の表示電極２および共通電極３が形成されていない部分の投影面上に、共通電極３の間隔に対して３０％の幅を持つ第３の電極４を有する基板を作成する。さらに、配向膜５を形成し、ラビングを行い、得られた基板を５μmのスペーサを用いて、ラビング方向がアンチパラレルになるように重ねあわせ、周辺部をシールして図３に示すような断面構造の液晶セルを作成する。ここで得られた液晶セルの空隙に誘電異方性５.７、屈折率異方性０.０９０のｐ型ネマチック液晶材料を注入する。次いで表示モードがノーマリーブラックとなるように偏光板を張り付け、本実施例の液晶表示装置を得る。本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。
本実施例による液晶表示装置の表示電極２と共通電極３の間に電圧を印加し、第３の電極４の電位を、インターディジタル電極間の電位差の１／４に相当する電位に制御して、上記実施例１と同様の測定法にて評価した結果、表３に示すような良好な表示特性が得られた。
【００３１】
実施例８．
実施例８による液晶表示装置の構成および材料は実施例７とすべて同じであり、表示電極２と共通電極３の間に電圧を印加した時の、第３の電極４の電位をインターディジタル電極間の電位差の１／２に相当する電位に制御するものである。これを上記実施例１と同様の測定法にて評価した結果、表３に示すような良好な表示特性が得られた。
【００３２】
実施例９．
実施例９による液晶表示装置の構成および材料は実施例７とすべて同じであり、表示電極２と共通電極３の間に電圧を印加した時の、第３の電極４の電位をインターディジタル電極間の電位差の３／４に相当する電位に制御するものである。これを上記実施例１と同様の測定法にて評価した結果、表３に示すような良好な表示特性が得られた。
【００３３】
実施例１０．
実施例１０では、第３の電極の幅を対向する基板の共通電極３の間隔に対して５０％にし、それ以外は上記実施例７〜９と同様の構成および材料の液晶表示装置を作成し、表示電極２と共通電極３の間に電圧を印加した時の、第３の電極４の電位をインターディジタル電極間の電位差の１／２に相当する電位に制御するものである。なお、本実施例で用いた配向膜と液晶のプレチルトは、クリスタルロテーション法により３度であった。これを上記実施例１と同様の測定法にて評価した結果、表３に示すような良好な表示特性が得られた。
【００３４】
【発明の効果】
以上のように、この発明によれば、表示電極および共通電極が形成された基板に対向する基板上に第３の電極を配置し、この第３の電極は、その隣接する各電極が、それらの間に他の電極を挟むことなく、少なくともそれらの一部が共通電極の投影面上に位置し、その幅が対向する共通電極の各電極の幅の１０％よりも大きく、且つ共通電極の各電極に隣接する表示電極の各電極の投影面上に及ばない範囲で形成されており、表示電極および共通電極間に電圧を印加するとともに第３の電極の電位を共通電極と同一電位に制御することにより、液晶分子が効率的に水平方向の電界に沿って配列され、残像のない、視覚特性に優れた液晶表示装置が得られる。
また、第３の電極を表示電極および共通電極の投影面でない領域に配置し、表示電極および共通電極間に電圧を印加するとともに第３の電極の電位を表示電極と共通電極との間の電位差のほぼ１／２に相当する電位に制御することにより、液晶分子が効率的に水平方向の電界に沿って配列され、残像のない、視覚特性に優れた液晶表示装置が得られる。
【００３５】
さらに、正の誘電異方性を有する液晶材料を用いることができるので、液晶表示装置の駆動電圧の低下が図られる。
【図面の簡単な説明】
【図１】 この発明の実施の形態１および実施例１〜３である液晶表示装置の構成を示す部分断面図および平面図である。
【図２】 この発明の実施の形態１の液晶表示装置の他の構成例を示す部分断面図および平面図である。
【図３】 この発明の実施の形態２および実施例７〜１０である液晶表示装置を示す部分断面図である。
【図４】 この発明の実施例４〜６である液晶表示装置を示す部分断面図である。
【図５】 従来の横電界方式の液晶表示装置にｐ型の液晶材料を用いた場合を示す説明図である。
【符号の説明】
１ 液晶分子、２ 表示電極、３ 共通電極、４ 第３の電極、５ 配向膜、
６、６６ 絶縁膜、７ ガラス基板、８ 偏光板、９ 電気力線。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a horizontal electric field type liquid crystal display device, and more particularly to improvement of visual characteristics and reduction of driving voltage.
[0002]
[Prior art]
Since the liquid crystal display device is thin and can be driven at a low voltage, it is widely used as a display device for a wristwatch, a calculator, or the like. In particular, a TN liquid crystal display device incorporating an active switch element such as a TFT (thin film transistor) exhibits a display characteristic similar to that of a CRT, and thus has been used for a word processor, a display of a personal computer, a television, and the like. However, in the TN liquid crystal display device, the viewing angle is narrow in halftone display, and a large difference in color or contrast occurs between the peripheral edge and the center of the display screen. This phenomenon is a method in which the optical rotation is controlled by applying an electric field to a p-type nematic liquid crystal material and causing the liquid crystal molecules to stand along the electric field direction, and the rising direction of the liquid crystal molecules is determined. I get up because I am. Therefore, in the TN liquid crystal display device, the problem of viewing angle cannot be fundamentally solved.
[0003]
In order to solve this problem, the liquid crystal molecules are rotated by applying an electric field in the horizontal direction, that is, in the horizontal direction to the substrate in a state where the liquid crystal molecules are aligned as in the TN liquid crystal display method, so A lateral electric field method for controlling refraction has been proposed. In this lateral electric field method, an interdigital electrode is formed on a substrate, a voltage is applied between the electrodes, and a horizontal electric field is formed on the substrate. Nematic liquid crystal is used.
[0004]
[Problems to be solved by the invention]
As described above, the conventional lateral electric field type liquid crystal display device generally uses n-type nematic liquid crystal having a small dielectric anisotropy, and thus has a problem that the drive voltage becomes high. FIG. 5 is a partial cross-sectional view for explaining the alignment state of liquid crystal when p-type nematic liquid crystal is used in a conventional lateral electric field type liquid crystal display device. In the figure, 1 is a liquid crystal molecule, 2 is a display electrode, 3 is a common electrode, and both the display electrode 2 and the common electrode 3 are interdigital electrodes. Reference numeral 5 denotes an alignment film, 6 denotes an insulating film, 7 denotes a glass substrate, 8 denotes a polarizing plate, and 9 denotes lines of electric force. As shown in FIG. 5, when a p-type nematic liquid crystal 1 is used in a conventional horizontal electric field type liquid crystal display device, when a voltage is applied between the interdigital display electrode 2 and the common electrode 3, The lines of electric force 9 are distorted and the liquid crystal molecules 1 try to align along the direction of the electric field, so that the liquid crystal alignment collides near the center between the electrodes and disclination occurs. Since the occurrence / disappearance of disclination is accompanied by hysteresis, there is a problem that an afterimage is generated and display quality is deteriorated.
[0005]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a horizontal electric field type liquid crystal display device which can be driven at a low voltage and has little afterimage.
[0006]
[Means for Solving the Problems]
The liquid crystal display device according to the present invention includes a display electrode comprising a plurality of electrodes arranged in parallel on a substrate, and a common electrode comprising a plurality of electrodes arranged in parallel and alternately with the display electrodes on the same substrate. And a third electrode disposed on the substrate facing the substrate, and a liquid crystal disposed between the two substrates via an alignment film, and each of the adjacent electrodes includes a third electrode. , At least part of them is located on the projection surface of the common electrode without sandwiching other electrodes between them, and the width is larger than 10% of the width of each electrode of the opposing common electrode and common It is formed in a range that does not reach the projection surface of each electrode of the display electrode adjacent to each electrode of the electrode, and a voltage is applied between the display electrode and the common electrode, and the potential of the third electrode is controlled to the same potential as the common electrode And an electric field is generated almost horizontally on the substrate surface. And controls the optical properties by the response surface of the liquid crystal is.
[0007]
Further, a display electrode made up of a plurality of electrodes arranged in parallel on the substrate, a common electrode made up of a plurality of electrodes arranged in parallel and alternately with the display electrodes on the same substrate, and facing the substrate A third electrode disposed on a region that is not a projection surface of the display electrode and the common electrode, and a liquid crystal disposed between the two substrates via an alignment film; A voltage is applied between the electrode and the common electrode, and the potential of the third electrode is controlled to a potential corresponding to approximately half of the potential difference between the display electrode and the common electrode, and the electric field is applied to the substrate surface in a substantially horizontal direction. The optical characteristics are controlled by causing the liquid crystal to generate an in-plane response.
Furthermore, the liquid crystal has positive dielectric anisotropy.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a partial cross-sectional view and a plan view showing the configuration of a lateral electric field type liquid crystal display device according to Embodiment 1 of the present invention. FIG. 1A is a partial sectional view showing a liquid crystal display device according to the present embodiment, which is composed of a substrate having an interdigital electrode on the surface and a counter substrate, and FIG. 1B is a structure of the interdigital electrode. FIG. In the figure, 1 is a liquid crystal molecule, 2 is a display electrode, 3 is a common electrode, and both the display electrode 2 and the common electrode 3 have an interdigital shape. Further, 4 is a third electrode disposed on the substrate facing the substrate on which the display electrode 2 and the common electrode 3 are formed, 5 is an alignment film, 6 is an insulating film, 7 is a glass substrate, and 8 is a polarizing plate. Show. The third electrode 4 in this embodiment, the electrodes thereof adjacent without sandwiching the other electrode between them, at least some of them are position on the projection surface of the common electrode 3 .
[0009]
In the liquid crystal display device according to the present embodiment, the liquid crystal 1 is disposed between a pair of substrates with an alignment film 5 interposed therebetween, and an interdigital electrode formed by being insulated from each other on one substrate, the display electrode 2 and An in-plane response type liquid crystal display device that controls optical characteristics by applying a voltage between common electrodes 3 to generate an electric field in a substantially horizontal direction on a substrate surface and rotating liquid crystal molecules 1 in an in-plane direction. The third electrode 4 is provided on the substrate opposite to the substrate on which the interdigital electrode is formed, and the electric field in the lateral direction is efficiently applied to the liquid crystal molecules 1 by controlling the potential of the third electrode 4. Thus, a liquid crystal display device having excellent viewing angle characteristics with a low driving voltage is obtained. When the p-type nematic liquid crystal 1 is used in a conventional lateral electric field type liquid crystal display device in which the third electrode 4 is not provided, a voltage is applied between the display electrode 2 and the common electrode 3 as shown in FIG. At times, the lines of electric force 9 are distorted between the electrodes, and the liquid crystal molecules 1 try to align along the direction of the electric field, causing a liquid crystal alignment collision near the center between the electrodes and causing disclination. To do. Since the occurrence / disappearance of disclination is accompanied by hysteresis, there is a problem that an afterimage is generated and display quality is deteriorated. According to the present invention, since the electric field can be formed horizontally on the substrate surface by providing the third electrode 4, there is no liquid crystal alignment collision and no disclination occurs, that is, there is no afterimage. can get. In the present embodiment, at least a part of the third electrode 4 is formed on the projection surface of the common electrode 3 formed on the opposing substrate, and is controlled to the same potential as the common electrode 3. Yes.
[0010]
When the third electrode 4 is formed on the counter substrate and controlled to the same potential as the common electrode 3, the width of the third electrode 4 is more than 10% of the width of each electrode of the common electrode 3 facing the third electrode 4. It is possible to form a large area that does not reach the projection surface of each electrode of the display electrode 2 adjacent to each electrode of the common electrode 3 facing each other . When the width of the third electrode 4 is narrower than 10% of the width of the common electrode 3, the effect of providing the third electrode 4 is small, and when applied to the projection surface of the adjacent display electrode 2, a lateral electric field is applied to the liquid crystal molecules 1. Is not applied. However, the third electrode 4 does not need to be formed on all the projection surfaces of the common electrode 3 facing each other. For example, a black matrix formed of a conductive material provided on the counter substrate is used as the third electrode 4. Also good.
[0011]
Further, the shape of the interdigital electrode is not limited to a shape in which a plurality of display electrodes 2 and a common electrode 3 are alternately arranged on the same plane as shown in FIG. 1, for example, an insulating film as shown in FIG. Alternatively, the display electrode 2 and the common electrode 3 may be formed with the electrode 6 interposed therebetween. In FIG. 2, 66 indicates an insulating film, and the same reference numerals indicate the same or corresponding parts. However, the electrode structure may be any shape that can apply a lateral electric field to the liquid crystal molecules 1, and is not limited to the shape shown here. In this embodiment, in order to provide all the matrix driving wirings on the pair of substrates, it is necessary to insulate the wirings from each other. Therefore, as a method of providing insulation between at least two interdigital electrodes, that is, the display electrode 2 and the common electrode 3, an insulating layer made of an inorganic material or organic material such as SiOX or SiNX is provided on the substrate, Alternatively, an interdigital electrode may be provided on the side surface.
[0012]
As the liquid crystal material used in the liquid crystal display device of the present invention, a nematic liquid crystal material can be used. As the type of liquid crystal material, any of p-type nematic liquid crystal and n-type nematic liquid crystal material can be used, but a liquid crystal material having a large dielectric anisotropy is easily obtained, and p-type which is effective for low voltage driving. It is preferable to use the nematic liquid crystal material. As the substrate material, glass, quartz, silicon, or the like can be used, but at least one of the substrates must be a transparent substrate in order to be used as a transmissive or reflective liquid crystal display device. As the alignment film material, an organic material such as polyimide and PVA, or an oblique deposition film of an inorganic material such as SiOX can be used. When the liquid crystal material and the alignment film are combined, if the pretilt angle exceeds 5 degrees, the visual characteristics are distorted. Therefore, the pretilt angle is preferably 5 degrees or less. Furthermore, as the electrode material, conductive metals such as Al, Cr, Ti, Cu, Mo, Ta, In, SnO 2 and ITO, metal oxides, conductive polymers, and the like can be used.
[0013]
As described above, according to the present embodiment, the third electrode 4 is formed on the projection surface of the common electrode 3 on the substrate facing the substrate on which the interdigital display electrode 2 and the common electrode 3 are formed. By providing and controlling the potential of the third electrode 4 to the same potential as that of the common electrode 3, a lateral electric field can be efficiently applied to the liquid crystal molecules 1, so that the viewing angle characteristics are excellent with a low driving voltage. A liquid crystal display device can be obtained.
[0014]
Embodiment 2. FIG.
FIG. 3 is a partial cross-sectional view showing a configuration of a horizontal electric field type liquid crystal display device according to the second embodiment of the present invention. In the figure, the same and corresponding parts are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, the third electrode 4 is provided in a region that is not the projection plane of the display electrode 2 and the common electrode 3 on the substrate facing the substrate on which the interdigital display electrode 2 and the common electrode 3 are formed. By controlling the potential of the third electrode 4 independently of the potential of the interdigital electrode, a lateral electric field is efficiently applied to the liquid crystal molecules 1, and a liquid crystal having excellent viewing angle characteristics with a low driving voltage. A display device is obtained.
When the third electrode 4 is formed on the projection surface where the interdigital electrode is not formed as in the present embodiment, the interdigital electrode, that is, the display electrode 2 and the common electrode 3 or the third electrode. At least one of the four electrode materials must be a transparent electrode material. Furthermore, since the liquid crystal molecules 1 mainly rotate between the display electrode 2 and the common electrode 3, it is desirable that the third electrode 4 is made of a transparent electrode material.
[0015]
As the liquid crystal material, the substrate material, the alignment film material, and the electrode material used in the liquid crystal display device according to this embodiment, the same materials as those described in Embodiment 1 can be used. Further, the shape of the interdigital electrode is not limited to the structure shown in FIG. 3 in which the display electrode 2 and the common electrode 3 are formed on the same plane, and may be a multilayer structure with an insulating film interposed therebetween. Any shape that can apply a lateral electric field may be used.
[0016]
【Example】
Examples of the liquid crystal display device according to the present invention will be described below. The measurement method of the liquid crystal display device created first will be described. The driving voltage is a voltage that gives the maximum transmittance when a voltage is applied between the display electrode 2 and the common electrode 3 and the amplitude is increased. The potential of the third electrode 4 is as described in the individual examples. When there is a difference of 0.1 V or more between the voltage-transmittance characteristics when the application is raised and when it is lowered, there is hysteresis that causes afterimage. The viewing angle was set to give a contrast of 10: 1. At this time, the longitudinal direction of the interdigital electrode was set to the top and bottom, and the direction orthogonal to this was set to the left and right.
Example 1.
A method for manufacturing a liquid crystal display device that is Embodiment 1 of the present invention will be described below.
Table 1 shows the evaluation results of the liquid crystal display devices according to Examples 1 to 3 and the comparative example.
[0017]
[Table 1]
Figure 0003746333
[0018]
An ITO film is formed on a single glass substrate, and an interdigital display electrode 2 and a common electrode 3 as shown in FIG. 1B are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, an ITO film is formed on a glass substrate, and a substrate having the third electrode 4 at a ratio of one to five on the projection surface of the opposing common electrode 3 is formed. The width of the third electrode is the same as that of the common electrode. Further, the alignment film 5 is formed and rubbed, and the obtained substrate is overlapped using a 5 μm spacer so that the rubbing direction is antiparallel, and the peripheral portion is sealed to form a liquid crystal cell. A p-type nematic liquid crystal material having a dielectric anisotropy of 5.7 and a refractive index anisotropy of 0.090 is injected into the gap of the liquid crystal cell obtained here. Next, a polarizing plate is pasted so that the display mode is normally black, and the liquid crystal display device of this embodiment is obtained. The pretilt between the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method.
[0019]
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the above measurement method is used. As a result of evaluation, no occurrence of disclination was observed, and good display characteristics as shown in Table 1 were obtained.
[0020]
Comparative example.
As a comparative example of Example 1, when the third electrode 4 was not formed on the counter substrate and the liquid crystal display device formed with the same configuration and materials as those of Example 1 was otherwise measured and evaluated, Disclination occurred and hysteresis was observed. Further, the voltage at which the maximum transmittance was obtained was higher than that in Example 1.
[0021]
Example 2
A method for manufacturing a liquid crystal display device that is Embodiment 2 of the present invention will be described below.
A Cr film is formed on a single glass substrate, and an interdigital display electrode 2 and a common electrode 3 as shown in FIG. 1B are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, a Cr film is formed on a glass substrate, and a substrate having the third electrode 4 at a ratio of one to five on the projection surface of the opposing common electrode 3 is formed. The width of the third electrode is the same as that of the common electrode. The subsequent steps are performed in the same manner as in Example 1.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the same as in the first embodiment. As a result of evaluation by the measurement method, no disclination was observed, and good display characteristics as shown in Table 1 were obtained.
[0022]
Example 3
A method for manufacturing a liquid crystal display device that is Embodiment 3 of the present invention will be described below.
An ITO film is formed on a single glass substrate, and an interdigital display electrode 2 and a common electrode 3 as shown in FIG. 1B are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, a Cr film is formed on a glass substrate, and a substrate having the third electrode 4 at a ratio of one to five on the projection surface of the opposing common electrode 3 is formed. The width of the third electrode is the same as that of the common electrode. The subsequent steps are performed in the same manner as in Example 1.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the same as in the first embodiment. As a result of evaluation by this measurement method, good display characteristics as shown in Table 1 were obtained.
[0023]
Example 4
A method for manufacturing a liquid crystal display device that is Embodiment 4 of the present invention will be described below. In addition, Table 2 shows the evaluation results of the liquid crystal display devices according to Examples 4 to 6.
[0024]
[Table 2]
Figure 0003746333
[0025]
A Cr film is formed on one glass substrate, and an interdigital display electrode 2 and a common electrode 3 are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, a Cr film is formed on a glass substrate, and a substrate having a third electrode 4 having a width of 50% with respect to the width of the common electrode 3 is formed on the projection surface of the opposing common electrode 3. . Further, an alignment film 5 is formed and rubbed, and the obtained substrate is overlapped using a 5 μm spacer so that the rubbing direction is anti-parallel, and the peripheral portion is sealed and the cross section shown in FIG. A liquid crystal cell having a structure is prepared. A p-type nematic liquid crystal material having a dielectric anisotropy of 5.7 and a refractive index anisotropy of 0.090 is injected into the gap of the liquid crystal cell obtained here. Next, a polarizing plate is pasted so that the display mode is normally black, and the liquid crystal display device of this embodiment is obtained. The pretilt between the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the same as in the first embodiment. As a result of evaluation by this measurement method, good display characteristics as shown in Table 2 were obtained.
[0026]
Embodiment 5 FIG.
A method for manufacturing a liquid crystal display device that is Embodiment 5 of the present invention will be described below.
A Cr film is formed on one glass substrate, and an interdigital display electrode 2 and a common electrode 3 are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, a Cr film is formed on a glass substrate, and a substrate having a third electrode 4 having a width of 100% with respect to the width of the common electrode 3 on the projection surface of the opposing common electrode 3 is formed. . The subsequent steps are performed in the same manner as in Example 4. Note that the pretilt of the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the same as in the first embodiment. As a result of evaluation by this measurement method, good display characteristics as shown in Table 2 were obtained.
[0027]
Example 6
A method for manufacturing a liquid crystal display device that is Embodiment 6 of the present invention will be described below.
A Cr film is formed on one glass substrate, and an interdigital display electrode 2 and a common electrode 3 are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, a Cr film is formed on a glass substrate, and a substrate having a third electrode 4 having a width of 150% with respect to the width of the common electrode 3 is formed on the projection surface of the opposing common electrode 3. . The subsequent steps are performed in the same manner as in Example 4. Note that the pretilt of the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to the present embodiment, and the potential of the third electrode 4 is controlled to the same potential as the potential of the common electrode 3, and the same as in the first embodiment. As a result of evaluation by this measurement method, good display characteristics as shown in Table 2 were obtained.
[0028]
Example 7
A method for manufacturing a liquid crystal display device that is Embodiment 7 of the present invention will be described below. Table 3 shows the evaluation results of the liquid crystal display devices according to Examples 7 to 10.
[0029]
[Table 3]
Figure 0003746333
[0030]
A Cr film is formed on one glass substrate, and an interdigital display electrode 2 and a common electrode 3 are formed using a positive photosensitive resist. Next, after the alignment film 5 is formed on the substrate, a rubbing process is performed in a direction shifted by 10 degrees from a direction perpendicular to the longitudinal direction of the interdigital electrode. As an opposing substrate, an ITO film is formed on a glass substrate, and a width of 30% of the interval between the common electrodes 3 is formed on the projection surface of the portion of the opposing substrate where the display electrode 2 and the common electrode 3 are not formed. A substrate having the third electrode 4 is prepared. Further, an alignment film 5 is formed and rubbed, and the obtained substrate is overlapped using a 5 μm spacer so that the rubbing direction is anti-parallel, and the periphery is sealed and the cross section shown in FIG. A liquid crystal cell having a structure is prepared. A p-type nematic liquid crystal material having a dielectric anisotropy of 5.7 and a refractive index anisotropy of 0.090 is injected into the gap of the liquid crystal cell obtained here. Next, a polarizing plate is pasted so that the display mode is normally black, and the liquid crystal display device of this embodiment is obtained. The pretilt between the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method.
A voltage is applied between the display electrode 2 and the common electrode 3 of the liquid crystal display device according to this embodiment, and the potential of the third electrode 4 is controlled to a potential corresponding to ¼ of the potential difference between the interdigital electrodes. As a result of evaluation by the same measurement method as in Example 1, good display characteristics as shown in Table 3 were obtained.
[0031]
Example 8 FIG.
The configuration and materials of the liquid crystal display device according to Example 8 are all the same as in Example 7, and the potential of the third electrode 4 when the voltage is applied between the display electrode 2 and the common electrode 3 is set between the interdigital electrodes. The potential is controlled to a potential corresponding to ½ of the potential difference. As a result of evaluating this by the same measurement method as in Example 1, good display characteristics as shown in Table 3 were obtained.
[0032]
Example 9
The configuration and materials of the liquid crystal display device according to Example 9 are all the same as those of Example 7, and the potential of the third electrode 4 when the voltage is applied between the display electrode 2 and the common electrode 3 is set between the interdigital electrodes. The potential is controlled to a potential corresponding to 3/4 of the potential difference. As a result of evaluating this by the same measurement method as in Example 1, good display characteristics as shown in Table 3 were obtained.
[0033]
Example 10
In Example 10, the width of the third electrode is set to 50% with respect to the interval between the common electrodes 3 of the opposing substrate, and a liquid crystal display device having the same configuration and material as those of Examples 7 to 9 is prepared. When the voltage is applied between the display electrode 2 and the common electrode 3, the potential of the third electrode 4 is controlled to a potential corresponding to 1/2 of the potential difference between the interdigital electrodes. Note that the pretilt of the alignment film and the liquid crystal used in this example was 3 degrees by the crystal rotation method. As a result of evaluating this by the same measurement method as in Example 1, good display characteristics as shown in Table 3 were obtained.
[0034]
【The invention's effect】
As described above, according to the present invention, the third electrode is disposed on the substrate opposite to the substrate on which the display electrode and the common electrode are formed, and each of the adjacent electrodes includes the third electrode. Without sandwiching other electrodes between them, at least some of them are located on the projection plane of the common electrode, the width of which is larger than 10% of the width of each electrode of the opposing common electrode, and the common electrode It is formed in a range that does not reach the projection surface of each electrode of the display electrode adjacent to each electrode, and a voltage is applied between the display electrode and the common electrode, and the potential of the third electrode is controlled to the same potential as the common electrode. By doing so, a liquid crystal display device in which liquid crystal molecules are arranged efficiently along a horizontal electric field, and there is no afterimage, and excellent visual characteristics can be obtained.
In addition, the third electrode is arranged in a region where the display electrode and the common electrode are not projected, and a voltage is applied between the display electrode and the common electrode, and the potential of the third electrode is set to a potential difference between the display electrode and the common electrode. By controlling to a potential corresponding to approximately 1/2 of the above, liquid crystal molecules are efficiently aligned along a horizontal electric field, and a liquid crystal display device having excellent visual characteristics with no afterimage is obtained.
[0035]
Furthermore, since a liquid crystal material having positive dielectric anisotropy can be used, the driving voltage of the liquid crystal display device can be reduced.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view and a plan view showing a configuration of a liquid crystal display device according to Embodiment 1 and Examples 1 to 3 of the present invention.
FIGS. 2A and 2B are a partial cross-sectional view and a plan view showing another configuration example of the liquid crystal display device according to the first embodiment of the invention. FIGS.
FIG. 3 is a partial sectional view showing a liquid crystal display device which is Embodiment 2 and Examples 7 to 10 of the present invention.
FIG. 4 is a partial sectional view showing a liquid crystal display device that is Embodiments 4 to 6 of the present invention.
FIG. 5 is an explanatory diagram showing a case where a p-type liquid crystal material is used in a conventional horizontal electric field type liquid crystal display device.
[Explanation of symbols]
1 liquid crystal molecule, 2 display electrode, 3 common electrode, 3rd electrode, 5 alignment film,
6, 66 Insulating film, 7 glass substrate, 8 polarizing plate, 9 lines of electric force.

Claims (3)

基板上に平行に配置された複数本の電極よりなる表示電極、
上記基板上に、上記表示電極と平行且つ交互に配置された複数本の電極よりなる共通電極、
上記基板に対向する基板上に配置された第３の電極、および
上記２枚の基板間に配向膜を介して配置された液晶を備え、
上記第３の電極は、その隣接する各電極が、それらの間に他の電極を挟むことなく、少なくともそれらの一部が上記共通電極の投影面上に位置し、その幅が対向する上記共通電極の各電極の幅の１０％よりも大きく、且つ上記共通電極の各電極に隣接する表示電極の各電極の投影面上に及ばない範囲で形成され、
上記表示電極および上記共通電極間に電圧を印加するとともに上記第３の電極の電位を上記共通電極と同一電位に制御し、基板面にほぼ水平方向に電界を発生させ上記液晶を面内応答させることにより光学特性を制御することを特徴とする液晶表示装置。A display electrode comprising a plurality of electrodes arranged in parallel on the substrate;
A common electrode comprising a plurality of electrodes arranged in parallel and alternately with the display electrode on the substrate;
A third electrode disposed on the substrate facing the substrate, and a liquid crystal disposed between the two substrates via an alignment film,
In the third electrode, the adjacent electrodes are located on the projection surface of the common electrode and the widths thereof are opposed to each other without sandwiching other electrodes between them. It is formed in a range that is larger than 10% of the width of each electrode of the electrode and does not reach on the projection surface of each electrode of the display electrode adjacent to each electrode of the common electrode,
A voltage is applied between the display electrode and the common electrode, and the potential of the third electrode is controlled to the same potential as the common electrode, and an electric field is generated in a substantially horizontal direction on the substrate surface to cause the liquid crystal to respond in-plane. A liquid crystal display device characterized in that the optical characteristics are controlled. 基板上に平行に配置された複数本の電極よりなる表示電極、
上記基板上に、上記表示電極と平行且つ交互に配置された複数本の電極よりなる共通電極、
上記基板に対向する基板上に形成され、上記表示電極および上記共通電極の投影面でない領域に配置された第３の電極、
上記２枚の基板間に配向膜を介して配置された液晶を備え、上記表示電極および上記共通電極間に電圧を印加するとともに、上記第３の電極の電位を上記表示電極と上記共通電極との間の電位差のほぼ１／２に相当する電位に制御し、基板面にほぼ水平方向に電界を発生させ上記液晶を面内応答させることにより光学特性を制御することを特徴とする液晶表示装置。A display electrode comprising a plurality of electrodes arranged in parallel on the substrate;
A common electrode comprising a plurality of electrodes arranged in parallel and alternately with the display electrode on the substrate;
A third electrode formed on a substrate opposite to the substrate and disposed in a region other than the projection surface of the display electrode and the common electrode;
A liquid crystal disposed between the two substrates via an alignment film, applying a voltage between the display electrode and the common electrode, and setting the potential of the third electrode to the display electrode and the common electrode; And a liquid crystal display device characterized by controlling the optical characteristics by generating an electric field in a substantially horizontal direction on the substrate surface and causing the liquid crystal to respond in-plane. . 上記液晶は、正の誘電異方性を有することを特徴とする請求項１または請求項２に記載の液晶表示装置。The liquid crystal, the liquid crystal display device according to claim 1 or claim 2 characterized by having a positive dielectric anisotropy.
JP20624396A 1996-08-05 1996-08-05 Liquid crystal display Expired - Fee Related JP3746333B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20624396A JP3746333B2 (en) 1996-08-05 1996-08-05 Liquid crystal display

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20624396A JP3746333B2 (en) 1996-08-05 1996-08-05 Liquid crystal display

Publications (2)

Publication Number Publication Date
JPH1048652A JPH1048652A (en) 1998-02-20
JP3746333B2 true JP3746333B2 (en) 2006-02-15

Family

ID=16520119

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20624396A Expired - Fee Related JP3746333B2 (en) 1996-08-05 1996-08-05 Liquid crystal display

Country Status (1)

Country Link
JP (1) JP3746333B2 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20000005858A (en) * 1998-06-05 2000-01-25 카네코 히사시 Liquid crystal display with wide viewing angle
JP4629135B2 (en) * 1998-06-23 2011-02-09 シャープ株式会社 Liquid crystal display device
JP4364332B2 (en) 1998-06-23 2009-11-18 シャープ株式会社 Liquid crystal display
JP3099812B2 (en) * 1998-07-30 2000-10-16 日本電気株式会社 Liquid crystal display
US20100091231A1 (en) 2008-10-14 2010-04-15 Seiko Epson Corporation Liquid crystal display device and electronic apparatus
JP5397982B2 (en) * 2008-10-14 2014-01-22 株式会社ジャパンディスプレイ Liquid crystal display device and electronic device
JP5485742B2 (en) * 2010-02-16 2014-05-07 セイコーインスツル株式会社 Liquid crystal display
WO2012077376A1 (en) * 2010-12-10 2012-06-14 凸版印刷株式会社 Liquid crystal display substrate and liquid crystal display device
JP5659768B2 (en) * 2010-12-16 2015-01-28 凸版印刷株式会社 Oblique electric field liquid crystal display device
WO2012086666A1 (en) * 2010-12-22 2012-06-28 シャープ株式会社 Liquid crystal panel and liquid crystal display device
CN102929045B (en) * 2012-10-08 2016-03-16 京东方科技集团股份有限公司 High polymer dispersed liquid crystal panel and preparation method thereof, liquid crystal indicator
CN105425480B (en) * 2015-12-31 2018-09-18 昆山龙腾光电有限公司 The liquid crystal display device and its view angle switch method of switchable viewing angle

Also Published As

Publication number Publication date
JPH1048652A (en) 1998-02-20

Similar Documents

Publication Publication Date Title
JP3811811B2 (en) Fringe field switching mode liquid crystal display
JP3120751B2 (en) In-plane switching LCD
JP4698031B2 (en) Multi-domain liquid crystal display device
JP3492582B2 (en) Liquid crystal display device and method of manufacturing the same
KR100531928B1 (en) A liquid crystal display
JP3234357B2 (en) Liquid crystal display
JP3296426B2 (en) Liquid crystal display device and method of manufacturing the same
JP3850002B2 (en) Liquid crystal electro-optical device
US20020041354A1 (en) Fringe field switching mode LCD
JPH1124068A (en) Method for forming dual domain inside liquid crystal layer, manufacture of liquid crystal display device using the method and liquid crystal display device
US20070030428A1 (en) Liquid crystal display
JPH07191336A (en) Liquid crystal display device
JP3031317B2 (en) Active matrix liquid crystal display
JP2000305100A (en) Liquid crystal display device
US6657694B2 (en) In-plane switching LCD device having slanted corner portions
TWI223119B (en) Liquid crystal display device
JP3746333B2 (en) Liquid crystal display
JPH09197420A (en) Liquid crystal element
JPH0961825A (en) Liquid crystal display device
JP3684398B2 (en) Optically compensated splay mode liquid crystal display
JP2000147511A (en) Liquid crystal display device and its manufacture
JP2002031802A (en) Active matrix type liquid crystal display device
JP2000194016A (en) Multidomain liquid crystal display element
JP2002062544A (en) Active matrix type liquid crystal display device
JP2856188B2 (en) Active matrix liquid crystal display panel

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20050323

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050426

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050624

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050823

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050928

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20051115

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20051122

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091202

Year of fee payment: 4

LAPS Cancellation because of no payment of annual fees