JPS63132220A - Ferroelectric liquid crystal element and its driving method - Google Patents
Ferroelectric liquid crystal element and its driving methodInfo
- Publication number
- JPS63132220A JPS63132220A JP27874386A JP27874386A JPS63132220A JP S63132220 A JPS63132220 A JP S63132220A JP 27874386 A JP27874386 A JP 27874386A JP 27874386 A JP27874386 A JP 27874386A JP S63132220 A JPS63132220 A JP S63132220A
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- ferroelectric liquid
- crystal element
- ferroelectric
- electric field
- 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.)
- Granted
Links
- 239000005262 ferroelectric liquid crystals (FLCs) Substances 0.000 title claims abstract description 67
- 238000000034 method Methods 0.000 title claims description 9
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 92
- 239000000758 substrate Substances 0.000 claims abstract description 52
- 230000005684 electric field Effects 0.000 claims abstract description 30
- 230000010287 polarization Effects 0.000 claims abstract description 20
- 230000002269 spontaneous effect Effects 0.000 claims abstract description 15
- 239000004990 Smectic liquid crystal Substances 0.000 claims description 7
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 5
- -1 polyethylene Polymers 0.000 claims description 4
- 239000004952 Polyamide Substances 0.000 claims description 2
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 239000004642 Polyimide Substances 0.000 claims description 2
- 229920002678 cellulose Polymers 0.000 claims description 2
- 239000001913 cellulose Substances 0.000 claims description 2
- 229920003055 poly(ester-imide) Polymers 0.000 claims description 2
- 229920002647 polyamide Polymers 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 229920001721 polyimide Polymers 0.000 claims description 2
- 150000002500 ions Chemical class 0.000 abstract description 23
- 238000009826 distribution Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- 230000004044 response Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000005621 ferroelectricity Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
- G02F1/137—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
- G02F1/139—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 based on orientation effects in which the liquid crystal remains transparent
- G02F1/141—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 based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野）
本発明は液晶光−シャッタやディスプレイ等に応用され
る強誘電性液晶素子およびその駆動方法に関し、更に詳
しくは、駆動特性および表示特性等か改善された強誘電
性液晶素子およびその駆動方法に関する。[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a ferroelectric liquid crystal element applied to liquid crystal light-shutters, displays, etc., and a method for driving the same. The present invention relates to an improved ferroelectric liquid crystal device and a method for driving the same.
（従来の技術）
従来、液晶を一対の対向電極間に挟持させてなる種々の
液晶素子が提案されているが、ＤＳＭ（Ｄｙｎａｍｉｃ
Ｓｃａｔｔｅｒｉｎｇ Ｍｏｄｅ）型の液晶素子以外
については、液晶層中のナトリウムイオン等のプラスイ
オンや塩素イオン等のマイナスイオン等の荷′市体をコ
ントロールする必要はあまり認められていない。(Prior Art) Conventionally, various liquid crystal elements in which a liquid crystal is sandwiched between a pair of opposing electrodes have been proposed, but DSM (Dynamic
For liquid crystal devices other than scattering mode type liquid crystal elements, there is little recognition of the need to control the transport of positive ions such as sodium ions and negative ions such as chlorine ions in the liquid crystal layer.
その理由は、現在香及しているＴＮ （Ｔｗｉｓｔ、ｅ
ｄＮｃｍａＬｉｃ）型液晶素子〔例えば、Ｍ、５ｃｈａ
ｄｔとＬｌｌｅｌｆ−ｒｉｃｈ著、“＾ｐｐｌｉｅｄ
Ｐｈｙｓｉｃｓ ＬｅｊＬｅｒｓ″、Ｖｏｌ。The reason for this is the TN (Twist, e
dNcmaLic) type liquid crystal element [for example, M, 5cha
dt and Lllelf-rich, “^pplied
Physics LejLers'', Vol.
＋８．Ｎｏ、４ （＋９７１．．２．１５ ）、
Ｐ、＋２７ 〜＋２８ の “Ｖｏｌｔ−ａｚａ
Ｄｅｐｅｎｄｅｎｔ ０ｐｔｉｃａｌ 八ｃｔ、
１ｖｉＬｙ ｏｆ ａ ＴｗｉｓｔｅｄＮｅｍａ
ｔｉｃ Ｌｉｑｕｉｄ （：ｒｙｓＬａｌ”参照］にお
いては、（１）過度のイオン流が液晶分子の配列を乱す
。+8. No, 4 (+971..2.15),
P, +27 ~ +28 “Volt-aza
Dependent 0ptical 8ct,
1viLy of a TwistedNema
In tic Liquid (see:rysLal), (1) excessive ion flow disturbs the arrangement of liquid crystal molecules.
（２）Ｍ晶材料の耐久性を低下させる。(2) Decreases the durability of the M crystal material.
（３）液晶層にかかる電圧の時定数が短くなる。(3) The time constant of the voltage applied to the liquid crystal layer becomes shorter.
等の影響がイオン等の導電性物質によって引き起される
ことが考えられたが、実際には液晶を適当に精製するこ
とによって液晶の体積抵抗を１０９ΩＣ１１以上に上げ
たり、素子の構成道程で液晶の汚染防止を効果的にする
等の手段により前述の（１）および（２）の問題は十分
対応可能であり、一方駆動方式においては、交流駆動方
式、リフレッシュ蓄積型駆動方式がＪ＾本となるため、
前記（３）の点も深刻な問題とはならなかったことによ
る。It was thought that these effects were caused by conductive substances such as ions, but in reality, by appropriately refining the liquid crystal, the volume resistance of the liquid crystal can be increased to 109ΩC11 or higher, and liquid crystal Problems (1) and (2) above can be sufficiently addressed by means such as effective prevention of contamination.On the other hand, as for drive systems, AC drive systems and refresh storage drive systems are To become
This is because point (3) above did not pose a serious problem.
これに対して、近年団界的に開発が進んでいる強誘電性
液晶素子の場合には、液晶層中のイオン等の荷電粒子の
挙動が、強誘電性液晶素子の特性に重大な影響を与える
ことが明らかにされている。On the other hand, in the case of ferroelectric liquid crystal devices, which have been developed in a collective manner in recent years, the behavior of charged particles such as ions in the liquid crystal layer has a significant effect on the characteristics of the ferroelectric liquid crystal device. It is clear that it will be given.
例えば、クラークとラガヴアル等の提案した強誘電性液
晶素子の構成においては、第１図に示されるように液晶
層内で各液晶分子の双極子の方向が揃い、液晶の自発分
極が生じている。For example, in the structure of a ferroelectric liquid crystal device proposed by Clark and Raghaval, as shown in Figure 1, the directions of the dipoles of each liquid crystal molecule are aligned in the liquid crystal layer, causing spontaneous polarization of the liquid crystal. .
この自発分極の存在は、強誘電性液晶素子のスイッチン
グ特性の条件であるため、この自発分極による電荷の片
寄りは、５ＳＦＬＣＤ（Ｓｕｒｆａｃｅ ５ｔａｂｉ−
Ｉｉｚｃｄ Ｆｅｒｒｏｅｌｅｃｔｒｉｃ Ｌｉｑｕｉ
ｄ ＣｒｙｓＬａｌ Ｄｅｖｉｃｅ）においては不可避
なものである。The presence of this spontaneous polarization is a condition for the switching characteristics of a ferroelectric liquid crystal element, so the unbalanced charge due to this spontaneous polarization is caused by 5SFLCD (Surface 5tabi-
Iizcd Ferroelectric Liqui
d CrysLal Device).
（発明か解決使用としている問題）
以上の如き強誘電性液晶素子における液晶分子の自発分
極は必然的なものであるが、この分極電荷の影響によっ
て、素子の非駆動時（すなわち、メモリー状態）におい
て液晶層の双安定性が損なわれ、液晶分子が昨安定性化
するという問題があることが判明した。(Problem to be solved by the invention) Spontaneous polarization of liquid crystal molecules in a ferroelectric liquid crystal element as described above is inevitable, but due to the influence of this polarized charge, when the element is not driven (i.e., in a memory state) It has been found that there is a problem in that the bistability of the liquid crystal layer is impaired and the liquid crystal molecules become unstable.
すなわち、素ｒ−内にはＩＴＯ電極等の透明電極が存在
し、その上に誘電体および配向膜を介して液晶層に接す
る構成が一般的であるが、その場合にメモリー状態（印
加電圧二〇）でも、液晶層内には液晶分子の分極電荷に
よって生じる電界が存在して、この電界によって液晶層
内に存在しているイオン性不純物が泳動して、イオンの
不均一な偏在が生じる。このイオンの偏在によって、逆
に液晶分子が拘束を受けるため、液晶分子のスイッチン
グ状態での双安定性か乱され、更には素子のメモリー性
自体の消滅をも誘引するという重大な間通が生じ、現在
の強誘電性液晶素子を光シヤツターやディスプレイとし
て考えた場合大きな障害となっている。In other words, it is common to have a transparent electrode such as an ITO electrode in the element r-, which is in contact with a liquid crystal layer via a dielectric and an alignment film. However, in the liquid crystal layer there is an electric field generated by the polarized charges of the liquid crystal molecules, and this electric field causes the ionic impurities present in the liquid crystal layer to migrate, resulting in uneven distribution of ions. This uneven distribution of ions conversely restricts the liquid crystal molecules, which disturbs the bistability of the liquid crystal molecules in the switching state, and even causes a serious problem in which the memory property of the device itself disappears. This is a major obstacle when considering current ferroelectric liquid crystal devices as optical shutters or displays.
従って、強誘電性液晶素子においては液晶層内に存在す
るイオンによる問題を解決することが要望されている。Therefore, in ferroelectric liquid crystal devices, it is desired to solve the problems caused by ions existing in the liquid crystal layer.
（問題点を解決するための手段）
本発明者は上記の如き従来技術の問題点を解決すべく鋭
意研究の結果、本発明を完成した。(Means for Solving the Problems) The present inventor completed the present invention as a result of intensive research to solve the problems of the prior art as described above.
すなわち、本発明は２発明からなり、その第一の発明は
、強誘電性液晶層を挟持する２枚の電極基板の強誘電性
液晶層に接する面の少なくとも一方を導電性としたこと
を特徴とする強誘電性液晶素子であり、且つ第二の発明
は、強誘電性液晶層を挟持する２枚の電極基板の強誘電
性液晶層に接する面のいずれか一方を導電性にした強誘
電性液晶素子において、素子の非表示時に直流電界を印
加することを特徴とする強誘電性液晶素子の駆動方法で
ある。That is, the present invention consists of two inventions, the first of which is characterized in that at least one of the surfaces in contact with the ferroelectric liquid crystal layer of two electrode substrates sandwiching the ferroelectric liquid crystal layer is electrically conductive. The second invention is a ferroelectric liquid crystal device in which either one of the surfaces of two electrode substrates sandwiching a ferroelectric liquid crystal layer in contact with the ferroelectric liquid crystal layer is conductive. This is a method of driving a ferroelectric liquid crystal element, which is characterized in that a DC electric field is applied when the element is not displaying information.
次に本発明を更に詳しく説明する。Next, the present invention will be explained in more detail.
本発明で使用する強誘電性液晶素子は、従来公知のいず
れの強誘電性液晶素子でもよく、いずれの素子にも本発
明を適用できるものである。The ferroelectric liquid crystal element used in the present invention may be any conventionally known ferroelectric liquid crystal element, and the present invention can be applied to any element.
すなわち、本発明で使用される強誘電性液晶は、加えら
れる電界に応じて第一の光学的安定状態と第二の光学的
安定状態とのいずれかを取るもの、すなわち、電界に対
して双安定性を有する液晶物質である。That is, the ferroelectric liquid crystal used in the present invention is one that takes either the first optically stable state or the second optically stable state depending on the applied electric field, that is, it is bidirectional with respect to the electric field. It is a stable liquid crystal material.
以上の如き双安定性を有する強誘電性液晶としては、強
誘電性を有するカイラルスメクティック液晶が好ましく
、そのうちでは特にカイラルスメクテ４ ”／りＣ相（
Ｓｍｃ’）またはＨ相（Ｓｍｔｌ’）の液晶が通してい
る。これらの強誘電性液晶は、“ＬＥＪＯ［ＪＲＮＡＬ
ＤＥ ＰＩＩＹＳＩＯＩＩＥ ＬＥＴＴＥＲ５″旦（
１、−６９） １９７５、’ＦｅｒｒｏｅｌｅｃＬｒｉ
ｃ Ｌｉｑｕｉｄ （：ｒｙｓｔａ）ｓに Ａｐｐｌｉ
ｅｄ Ｐｈ−ｙｓｉｃｓ Ｌｅｔｔｅｒｓ” ３６（１
１）１９８０、’Ｓｕｂｍｉｃｒｏ ５ｅｃｏｎｄ口１
ｓＬａｂｌｅ Ｅｌｅｃｔｒｏｏｐｔｉｃ Ｓｗｉ
ｔｃｈｉｎｇ ｉｎ ＬｉｑｕｉｄＣｒｙｓｔａｌ
ｓ７ ： “固体物理” １６（１４１）＋９８１
． ｒ液晶」等に記載されており、より具体的には、
例えば、デシロキシベンジリデン＝Ｐ′−アミノ−２−
メチルブチルシンナメート （ＤＯＢＡＭＢＧ）、ヘキ
シルオキシベンジリデン−Ｐ′−アミノ−２−クロロプ
ロビルシンナメート （１１０Ｂ Ａ ＣＰ Ｃ）およ
び４−ｏ−（２−メチル）−ブチルレゾルシリテン−４
′−オクチルアニリン （Ｍｒ３ＲＡ８）等が挙げられ
る。As the ferroelectric liquid crystal having bistability as described above, a chiral smectic liquid crystal having ferroelectricity is preferable, and among them, a chiral smectic liquid crystal having a chiral smectic 4''/C phase (
Smc') or H phase (Smtl') liquid crystal passes through. These ferroelectric liquid crystals are “LEJO[JRNAL
DE PIIYSIOIIE LETTER 5″ (
1, -69) 1975, 'FerroelecLri
c Liquid (:rysta)s Appli
ed Physics Letters” 36(1
1) 1980, 'Submicro 5econd mouth 1
sLable Electrooptic Swi
tching in LiquidCrystal
s7: “Solid State Physics” 16 (141) + 981
．． r liquid crystal” etc., and more specifically,
For example, decyloxybenzylidene=P'-amino-2-
Methylbutylcinnamate (DOBAMBG), hexyloxybenzylidene-P'-amino-2-chloroprobylcinnamate (110B A CP C) and 4-o-(2-methyl)-butylresolsiliten-4
'-octylaniline (Mr3RA8) and the like.
第２図示の例は強誘電性液晶素子の１例を模式的に示す
ものであり、図中の１と１′はＩｎ２Ｏ３、ＳｎＯ□あ
るいはＩＴＯ（Ｉｎｄｉｕｍ−Ｔｉｎ−Ｏｘｉｄｅ）等
の透明電極がコートされた基板（例えばガラス板）であ
り、これらの一対の基板の少なくとも一方には絶縁層お
よび配向膜（図示なし）が設けられ、これらの配向制御
膜の間に前記の如き液晶からなる液晶層２が、基板面に
垂直になるように配向したＳ＋ａＣ”相の液晶として封
入されている。The example shown in the second figure schematically shows an example of a ferroelectric liquid crystal element, and 1 and 1' in the figure are coated with transparent electrodes such as In2O3, SnO□ or ITO (Indium-Tin-Oxide). At least one of the pair of substrates is provided with an insulating layer and an alignment film (not shown), and a liquid crystal layer made of the liquid crystal as described above is provided between these alignment control films. 2 is sealed as an S+aC'' phase liquid crystal aligned perpendicular to the substrate surface.
太線で示した線３が液晶分子を表わしており、この液晶
分子３はその分子に直交した方向に双極子モーメント（
Ｐ工）４を有している。A thick line 3 represents a liquid crystal molecule, and this liquid crystal molecule 3 has a dipole moment (
P engineering) has 4.
このような強誘電性液晶素子の基板１と１′上の電極間
に一定の閾値以上の電圧を印加すると、液晶分子３のら
せん構造がほどけ、双極子モーメント（Ｐ±）４がすべ
て電界方向に向くように液晶分子３の配向方向を変える
ことができる。When a voltage higher than a certain threshold is applied between the electrodes on the substrates 1 and 1' of such a ferroelectric liquid crystal element, the helical structure of the liquid crystal molecules 3 is unraveled, and the dipole moments (P±) 4 are all directed in the direction of the electric field. The alignment direction of the liquid crystal molecules 3 can be changed so that the liquid crystal molecules 3 are oriented in the direction shown in FIG.
液晶分子３は細長い形状を有しており、その長袖方向と
短軸方向で屈折率の異方性を示し、従って、例えば、基
板面の上下に互いにクロスニコルの位置関係に配置した
偏光子を置けば、電圧印加極性によって光学特性が変化
する液晶光学変調素Ｔとなることは容易に理解される。The liquid crystal molecules 3 have an elongated shape and exhibit refractive index anisotropy in the long axis direction and the short axis direction. It is easily understood that if the liquid crystal optical modulator T is placed, the optical modulator T will be obtained, the optical characteristics of which change depending on the polarity of applied voltage.
更に液晶素子の厚さを充分に薄くした場合（例えば１μ
ｍ）には、第３図に示すように電界を印加していない状
態でも液晶分子のらせん構造はほどけ（非らせん構造）
、その双極ｆモーメントＰまたはＰ′は上向き（４ａ）
または下向き（４ｂ）のいずれかの状態をとる。このよ
うな素子にｍ３図に示す如く一定の閾値以上の極性の異
なる電界ＥまたはＥ′を所定時間付与すると、双極子モ
ーメントは電界ＥまたはＥ′の電界ベクトルに対応して
上向き４ａまたは下向き４ｂと向きを変え、それに応じ
て液晶分子は第１の配向状態５かあるいは第二の配向状
Ｒ５′の何れか一方に配向する。このような強誘電性液
晶素子を光学変３ＳＩ素子として用いることの利点は２
つある。Furthermore, if the thickness of the liquid crystal element is made sufficiently thin (for example, 1μ
m), as shown in Figure 3, the helical structure of the liquid crystal molecules unravels even when no electric field is applied (non-helical structure).
, whose bipolar f moment P or P' is upward (4a)
or downward (4b). When an electric field E or E' with a different polarity above a certain threshold value is applied to such an element for a predetermined time as shown in the m3 diagram, the dipole moment will be directed upward 4a or downward 4b in accordance with the electric field vector of the electric field E or E'. Accordingly, the liquid crystal molecules are aligned in either the first alignment state 5 or the second alignment state R5'. There are two advantages to using such a ferroelectric liquid crystal element as an optically variable 3SI element.
There is one.
第１には、応答速度が極めて速いこと、第２に液晶分子
の配向が双安定性状態を有することである。第２の点を
例えば第３図によって説明すると、電界Ｅを印加すると
液晶分子は第１の配白状聾５に配向するが、この状態で
は電界を切っても安定である。また、逆向きの電界Ｅ′
を印加すると、液晶分子は第２の配向状態５′に配向し
てその分子の向きを変えるが、やはり電界を切ってもこ
の状態に留まっている。また、与える電界Ｅが一定の閾
値を越えない限り、それぞれの配向状態にやはり維持さ
れている。このような応答速度の速さと、双安定性が有
効に実現されるには、素子としてできるだけ薄い方が好
ましく、一般的には０．５〜２０μｍ、特に１〜５μｍ
が適している。この種の強誘電性液晶を用いるマトリッ
クス電極構造を有する強誘電性液晶素子は、例えば、ク
ラークとラガバルにより、米国特許第４３６７９２４号
明細書に提案されている。Firstly, the response speed is extremely fast, and secondly, the alignment of liquid crystal molecules has a bistable state. To explain the second point with reference to FIG. 3, for example, when the electric field E is applied, the liquid crystal molecules are oriented in the first white alignment state 5, but in this state they are stable even when the electric field is turned off. Also, the electric field E' in the opposite direction
When the electric field is applied, the liquid crystal molecules align to the second alignment state 5' and change their orientation, but they remain in this state even after the electric field is turned off. Further, as long as the applied electric field E does not exceed a certain threshold value, each orientation state is maintained. In order to effectively realize such fast response speed and bistability, it is preferable that the element be as thin as possible, generally 0.5 to 20 μm, particularly 1 to 5 μm.
is suitable. A ferroelectric liquid crystal element having a matrix electrode structure using this kind of ferroelectric liquid crystal is proposed by Clark and Ragaval in US Pat. No. 4,367,924, for example.
以上は強誘電性液晶素子の構成の１例であるが、これら
の強誘電性液晶素子は前述の如く、液晶層内に存在する
イオンによって種々の問題を生しるものであった。The above is an example of the structure of a ferroelectric liquid crystal element, but as described above, these ferroelectric liquid crystal elements have caused various problems due to ions existing in the liquid crystal layer.
すなわち、強誘電性液晶は第１図に示したように分子双
極子に由来する自発分極を持ち、強請電性液晶が双安定
性を有する液晶層ｒでは、その分極によって誘起される
内部電界が発生している。In other words, as shown in Figure 1, the ferroelectric liquid crystal has spontaneous polarization derived from molecular dipoles, and in the liquid crystal layer r where the ferroelectric liquid crystal has bistability, the internal electric field induced by the polarization is It has occurred.
この内部電界は強誘電性液晶層に電圧が印加・無印加に
かかわらず常に存在している。This internal electric field always exists regardless of whether a voltage is applied to the ferroelectric liquid crystal layer or not.
面述した自発分極によって誘起された内部電界により、
強誘電性液晶内のイオン種が泳動し、これらのイオン種
は各電極方向に偏在せしめられる。そしてこれらイオン
の偏在はかなりの時間安定に存在する。Due to the internal electric field induced by the spontaneous polarization mentioned above,
Ion species within the ferroelectric liquid crystal migrate, and these ion species are unevenly distributed in the direction of each electrode. The uneven distribution of these ions remains stable for a considerable period of time.
以上の現象は以下の実験によって確かめられる。例えば
、第４図示のように透明電極７．７′上に配向膜等の絶
縁膜６．６′を設けた素子に、強誘電性液晶を封入し強
誘電性液晶素子を作る。The above phenomenon can be confirmed by the following experiment. For example, as shown in Figure 4, a ferroelectric liquid crystal element is produced by filling a ferroelectric liquid crystal in an element in which an insulating film 6.6' such as an alignment film is provided on a transparent electrode 7.7'.
その分子３の向きを一方の方向に向けて（自発分極の向
き、上→下）且つ電極７．７′を同電位にして放置する
と、その分極方向のみか安定になり、もう一方の状態が
実現できなくなり、液晶分子３の双安定性が消失する（
第４図ａ）。次にこの素子に上基板から下基板の方向に
数ボルトの外部電圧Ｅを印加して数分間放置しく第４図
ｂ）、再び上下電極を同電位にする（第４図Ｃ）と、今
度はもう一方の状態が安定になり、駆動パルスを印加し
ても液晶分子３を逆の状態に転移させることができない
。If the molecule 3 is left in one direction (direction of spontaneous polarization, top to bottom) and the electrodes 7 and 7' are left at the same potential, only that polarization direction becomes stable, and the other state becomes stable. cannot be realized, and the bistability of liquid crystal molecules 3 disappears (
Figure 4 a). Next, apply an external voltage E of several volts to this element in the direction from the upper substrate to the lower substrate, leave it for a few minutes (Fig. 4b), and make the upper and lower electrodes at the same potential again (Fig. 4C). The other state becomes stable, and even if a driving pulse is applied, the liquid crystal molecules 3 cannot be transferred to the opposite state.
これらの現象は第４図中のプラスおよびマイナスで表し
たイオンの偏在によりわかりやすく説明できる。These phenomena can be easily explained by the uneven distribution of ions represented by plus and minus signs in FIG.
第４図ａの場合は液晶層７−３の分極による内部電界、
第４図す、ｃの場合は外部電界によってイオン泳動が起
こり、それぞれのイオンの偏在により液晶分子３の分極
方向が安定化され、液晶分子の双安定性が低下し、液晶
分子の単安定性化現象が起こることがわかる。In the case of FIG. 4a, the internal electric field due to the polarization of the liquid crystal layer 7-3,
In the case of Figures 4 and c, iontophoresis occurs due to the external electric field, and the polarization direction of the liquid crystal molecules 3 is stabilized by the uneven distribution of each ion, the bistability of the liquid crystal molecules decreases, and the monostability of the liquid crystal molecules increases. It can be seen that this phenomenon occurs.
本発明は、これらの液晶分子の単安定性化を解決するた
めに強誘電性液晶層を挟持する２枚の型棒Ｊ、ζ板の強
誘電性液晶層に接する面のいずれか一方を導電性とする
ことによって、基板近傍に偏在するプラス荷電またマイ
ナス荷電を消滅させることかでき、その結果イオンの偏
在による液晶分子の単安定性化を防止し、上記の如き従
来技術の欠点を解決したものである。In order to solve the problem of monostability of these liquid crystal molecules, the present invention has developed two mold rods J and ζ plates that sandwich the ferroelectric liquid crystal layer by making one of the surfaces in contact with the ferroelectric liquid crystal layer conductive. This makes it possible to eliminate the positive and negative charges that are unevenly distributed near the substrate, thereby preventing the liquid crystal molecules from becoming monostable due to the uneven distribution of ions, and solving the above-mentioned drawbacks of the conventional technology. It is something.
上記の如き本発明を、本発明の一実施例を示す第５図を
参照して更に具体的に説明する。The present invention as described above will be explained in more detail with reference to FIG. 5 showing one embodiment of the present invention.
第５図は本発明の強誘電性液晶素子の一実施例の断面を
図解的に示す図であり、１．１′はガラス基板、７．７
′はガラス」↓板１．１′上に形成されたＩＴＯ等から
なる透明電極層、８は上側基板付近に偏在したプラス電
荷を有する荷電体、９は下側Ｊ＾板付近に偏在したマイ
ナス荷電体である。FIG. 5 is a diagram schematically showing a cross section of an embodiment of the ferroelectric liquid crystal element of the present invention, in which 1.1' is a glass substrate, 7.7
' is a transparent electrode layer made of ITO or the like formed on the plate 1.1', 8 is a charged body with a positive charge unevenly distributed near the upper substrate, and 9 is a negative electrode unevenly distributed near the lower J^ plate. It is a charged body.
２は液晶層を示し、５．５′はその中で採り得る２種の
液晶状態を示し、６はｋｔｌ、縁層を示す。2 indicates a liquid crystal layer, 5.5' indicates two types of liquid crystal states that can be taken therein, and 6 indicates a ktl, edge layer.
図示の通り５は分子内双極子としても同時に自発分極の
方向も」二側基板から手相へ矢印（−から十へ引くもの
とする）が向いているので、上下基板近傍の荷電体の偏
在によってその存在は安定化されている。これに対し、
５′に示す液晶分子の配置は双極子がイオンの偏在に対
して反対方向を向いているので電気的に極めて不安定な
状態であり、双安定性を打する液晶表示素子としては好
ましくない状態にある。As shown in the figure, 5 acts as an intramolecular dipole and at the same time, the direction of spontaneous polarization is also ``Since the arrow (assumed to be drawn from - to 10) is pointing from the second substrate to the palm, it is due to the uneven distribution of charged bodies near the upper and lower substrates. Its existence is stabilized. On the other hand,
The arrangement of liquid crystal molecules shown in 5' is an extremely unstable state electrically because the dipoles are oriented in the opposite direction to the uneven distribution of ions, and this is not a desirable state for a liquid crystal display element that violates bistability. It is in.
これに対して本発明の強誘電性液晶素子の場合には、上
基板側には絶縁層は形成されていないので導電性であり
、素子の非表示時に該素子に液晶分子５の自発分極によ
る電界を打ち消す方向に直流電界を印加することによっ
て上基板近傍に偏在したプラス荷電は消滅し、同時に反
対側の基板近傍に偏在したマイナス荷電も消滅すること
になる。On the other hand, in the case of the ferroelectric liquid crystal element of the present invention, since no insulating layer is formed on the upper substrate side, it is conductive, and when the element is not displayed, the element is caused by spontaneous polarization of the liquid crystal molecules 5. By applying a DC electric field in a direction that cancels out the electric field, the positive charges unevenly distributed near the upper substrate disappear, and at the same time, the negative charges unevenly distributed near the opposite substrate also disappear.
以上の如く強誘電性液晶層を挟持する２枚の電極基板の
強誘電性液晶に接する面のいずれか一方を導電性にする
ことにより、素子のイオンの偏在による液晶分子の単安
定性化を防止して液晶分子の双安定性を著しく向上させ
ることができる。As described above, by making one of the surfaces in contact with the ferroelectric liquid crystal of the two electrode substrates sandwiching the ferroelectric liquid crystal layer conductive, monostability of liquid crystal molecules due to uneven distribution of ions in the device can be prevented. This can significantly improve the bistability of liquid crystal molecules.
本発明の液晶素子において、液晶層が接する基板面の一
方を導電性にする方法としては、第５図示の如く、一方
の電極基板の面にのみ絶縁層を設ける方法の外、例えば
、２枚の電極基板の両方に絶縁層を設ける場合には、一
方の絶縁層の導電性を比抵抗値９３１００９．ｃｍ以下
、好ましくはρ＝１０４Ω、Ｃ１１以下にする方法等で
もよいものである。In the liquid crystal element of the present invention, as a method of making one of the substrate surfaces in contact with the liquid crystal layer conductive, in addition to a method of providing an insulating layer only on one electrode substrate surface as shown in FIG. When an insulating layer is provided on both electrode substrates, the conductivity of one insulating layer is set to a specific resistance value of 931009. cm or less, preferably ρ=104Ω, C11 or less.
また強誘電性液晶層に接する基板面にラビング処理を施
した配向制御膜を設けるのが好ましい。Further, it is preferable to provide an alignment control film subjected to a rubbing treatment on the substrate surface in contact with the ferroelectric liquid crystal layer.
このような場合には、例えば、両方の基板に配向制御膜
を設ける場合には、その一方の配向制御膜の導電性を、
ρ＝１０６Ω、ｃｍ以下、好ましくはρ＝１０４Ω、ｃ
ｍ以下にする方法、一方の′１“は極基板に絶縁層と配
向制御膜とを設け、且つ他方の電極基板に絶縁層を設け
ることなく電極上に配向制御ｌ漠を設ける場合には、こ
の配向−制御）模の導電性をρ＝１０６Ω、ｃｍ以下、
好ましくはρ＝ １０’Ω、ｃｍ以下にする方法等が有
効である。In such a case, for example, if alignment control films are provided on both substrates, the conductivity of one of the alignment control films may be
ρ=106Ω, cm or less, preferably ρ=104Ω, c
m or less, one method '1' is to provide an insulating layer and an orientation control film on the electrode substrate, and to provide an orientation control layer on the electrode without providing an insulating layer on the other electrode substrate, The conductivity of this orientation-control) model is ρ=106Ω, cm or less,
Preferably, a method of setting ρ=10′Ω, cm or less is effective.
上記配向制御膜は、ポリビニルアルコール、ポリイミド
、ポリアミド、ポリエステルイミド、セルロースまたは
ポリエチレン等から常法に従って形成でき、また配向制
御膜を導電性にするにはそれらの膜中に導電性粒子等を
包含させればよい。The above-mentioned alignment control film can be formed from polyvinyl alcohol, polyimide, polyamide, polyesterimide, cellulose, polyethylene, etc. by a conventional method, and in order to make the alignment control film electrically conductive, conductive particles or the like may be included in the film. That's fine.
尚、上記における比抵抗の測定は、ＡＳＴＭ（＾ＭＥＲ
１−ＣＡＮ ＮＡＴＩＯＮＡＬ ５ＴＡＮＤＡＲＤ）Ｄ
−２５７によって測定される値である。In addition, the measurement of specific resistance in the above is performed according to ASTM (^MER
1-CAN NATIONAL 5TANDARD)D
-257.
以上において素子を構成する基板、液晶、透明電極、絶
縁層、配向制御膜等はいずれも従来技術に準じて形成す
ればよい。In the above, the substrate, liquid crystal, transparent electrode, insulating layer, alignment control film, etc. constituting the element may all be formed according to conventional techniques.
（作用・効果）
以上の如き本発明によれば、強誘電性液晶素子の構成に
あたり、液晶層が接する電極基板のいずれか一方の面を
導電性にすることにより、その素子の非駆動時に直流電
圧を印加すれば、強誘電性液晶層中に発生したイオンの
偏在を中和することができ、その結果、素子の駆動時の
液晶分子の単安定性化が防止され、双安定性が著しく向
上するので素子の応答性をより高速化でき、表示特性や
メモリー特性を一層向上させることができる。(Operations/Effects) According to the present invention as described above, when configuring a ferroelectric liquid crystal element, by making one side of the electrode substrate in contact with the liquid crystal layer conductive, direct current flows when the element is not driven. By applying a voltage, it is possible to neutralize the uneven distribution of ions generated in the ferroelectric liquid crystal layer, and as a result, the liquid crystal molecules are prevented from becoming monostable when the device is driven, and bistability is significantly reduced. As a result, the response speed of the element can be further increased, and the display characteristics and memory characteristics can be further improved.
次に参考例および実施例を挙げて本発明を更に具体的に
説明する。Next, the present invention will be explained in more detail with reference to Reference Examples and Examples.
参考例１
液晶材料としてチッソ社製のｃｓ−ｉｏｓを用いた。
ＩＴＯ電極が形成されている２枚のガラス基板の両方に
５ｉ０２ｆｆ！２からなる絶縁層をスパッタ法により１
０００人の厚み形成し、その上にポリビニルアルコ−ル
トし乾燥硬化後、アセテート布で上記基板を一方向にラ
ビング処理した。このような２枚の基板を、スペーサー
を介して対向して貼り合せて素子を作成した。素：ｉ′
厚は、１〜１．４μｍであった。この素子に前記の液晶
材料を等方相となる温度１００℃にて注入した。素子−
の温度をコントロールしながら５℃／時間のスピードで
徐冷すると、素Ｙ−内の液晶はｃｈ相（コレステリック
相）、Ｓ１１１＾相（スメクティックＡ相）を経て、Ｓ
ＩＩＩＣ”相（カイラルスメクティックＣ相）に達する
。これらの相変化は、液晶素子の両側に偏光子と検光子
を配置することによって同定することができる。Reference Example 1 CS-IOS manufactured by Chisso Corporation was used as a liquid crystal material.
5i02ff on both of the two glass substrates on which ITO electrodes are formed! 1 by sputtering an insulating layer consisting of 2
After forming the substrate to a thickness of 0.000 mm, polyvinyl alcohol was applied thereon, and after drying and curing, the substrate was rubbed in one direction with an acetate cloth. Two such substrates were bonded together facing each other with a spacer interposed therebetween to create an element. Prime: i′
The thickness was 1 to 1.4 μm. The above-mentioned liquid crystal material was injected into this element at a temperature of 100° C. at which it became an isotropic phase. Element
When slowly cooled at a rate of 5°C/hour while controlling the temperature of
IIIC" phase (chiral smectic C phase). These phase changes can be identified by placing polarizers and analyzers on both sides of the liquid crystal element.
第５図において２種の安定状態のうち５′の方向に自発
分極を揃えるように９．０■のＤＣ電界をヒト基板に印
加して約１０時間放置した。その結果、５の方向は安定
であったが、５′の方向は不安定であり、２つの安定状
態間のコントラストは殆どなかった。In FIG. 5, a DC electric field of 9.0 μ was applied to the human substrate so as to align the spontaneous polarization in the 5' direction of the two stable states, and the substrate was left for about 10 hours. As a result, the direction 5 was stable, but the direction 5' was unstable, and there was almost no contrast between the two stable states.
駆動電圧印加時と後の分子状態を顕微鏡で観察すると自
発分極が５の方向から５′の方向へ反転するように駆動
した時、電圧印加中は５′の方向へ反転した分子が電圧
が切れた後に５の方向へ再び反転し安定となり、５の方
向へ単安定性となっていることがわかった。Observing the state of the molecules under a microscope before and after applying a driving voltage, when driving so that the spontaneous polarization reverses from the 5 direction to the 5' direction, the molecules whose spontaneous polarization was reversed from the 5' direction to the 5' direction during the voltage application showed that the voltage was turned off. After that, it reversed again in the direction of 5 and became stable, and it was found that it became monostable in the direction of 5.
実施例１
参考例１において液晶素子のいずれか一方の電極基板上
に絶縁層と配向膜を形成せずに、他はすべて参考例１と
同じ条件で素子を作成し、全く同じ駆動を行った。Example 1 In Reference Example 1, an element was created under the same conditions as Reference Example 1, except that an insulating layer and an alignment film were not formed on one of the electrode substrates of the liquid crystal element, and the device was driven in exactly the same way. .
その結果、第５図の５の方向は安定で、５′の方向は不
安定であったが、２つの安定状態間でのコントラストは
参考例の場合に比較して著しく大きかった。顕微鏡で自
発分極が５の方向から５′の方向へ反転する様子を観察
すると５′の方向は全く不安定ではなく、電圧が切れた
後も５′の方向に十分に安定に存在していることがわか
った。As a result, although the direction 5 in FIG. 5 was stable and the direction 5' was unstable, the contrast between the two stable states was significantly larger than that of the reference example. Observing with a microscope how the spontaneous polarization reverses from the 5 direction to the 5' direction, the 5' direction is not unstable at all, and even after the voltage is turned off, it remains sufficiently stable in the 5' direction. I understand.
この結果から、液晶素子のいずれか一方の基板に絶縁層
と配向膜を形成せずにおき、直流バイアスで絶縁層の形
成されていない側にプラスまたはマイナスのいずれか一
方の荷電体を偏在させ、電極上にイオンを吸着し、その
極性を消すことで荷電体の偏在による液晶分子配列の電
気的不安定性が軽減でき、メモリー状態を利用した表示
が十分に可能となった。From this result, it was found that an insulating layer and an alignment film were not formed on one of the substrates of the liquid crystal element, and either a positive or negative charged body was unevenly distributed on the side where the insulating layer was not formed using a DC bias. By adsorbing ions onto the electrodes and erasing their polarity, it was possible to reduce the electrical instability of liquid crystal molecular alignment caused by the uneven distribution of charged bodies, making it possible to display images using memory states.
実施例２
実施例１の液晶素子を用いて荷電体を偏在させるため、
９．ＯｖのＤＣ電界を実施例１と同一方向に上下基板間
に印加して放置した。実施例１で安定となった方向から
不安定となった方向に液晶分子配列がすべて反転するた
めの電圧（飽和電圧）の経時変化を測定した。測定結果
を第６図に示した。液晶素子のいずれか一方の電極基板
上に絶縁層と配向膜を形成しなかった試料では、両側の
電極基板上に絶縁層と配向膜を形成した試料に比べ明ら
かに飽和電圧の増加が遅く、しかも小さいことがわかる
。このような飽和電圧の上昇は、液晶素子中にイオン等
の荷電体が偏在するためおこるものであり、上記結果よ
り液晶素子のいずれか一方の電極基板上に絶縁層と配向
膜を形成せずにおき、直流バイアスを印加することによ
り荷電体の偏在の影響が軽減できることが明らかとなっ
た。Example 2 In order to unevenly distribute charged bodies using the liquid crystal element of Example 1,
9. A DC electric field of Ov was applied between the upper and lower substrates in the same direction as in Example 1 and left. The change over time of the voltage (saturation voltage) required to completely reverse the liquid crystal molecular arrangement from the stable direction to the unstable direction in Example 1 was measured. The measurement results are shown in FIG. In the sample in which the insulating layer and alignment film were not formed on either electrode substrate of the liquid crystal element, the increase in saturation voltage was clearly slower than in the sample in which the insulating layer and alignment film were formed on both electrode substrates. And you can see that it's small. Such an increase in saturation voltage occurs because charged bodies such as ions are unevenly distributed in the liquid crystal element, and from the above results, it is possible to avoid forming an insulating layer and an alignment film on either one of the electrode substrates of the liquid crystal element. It has become clear that the effects of uneven distribution of charged bodies can be reduced by applying a DC bias.
実施例３
参考例１において、一方の電極基板上に絶縁層を設け、
他方の電極基板上にポリビニルアルコールから配向制御
膜（４００人）を設け、他は参考例１と同様に本発明の
液晶素子を構成した。Example 3 In Reference Example 1, an insulating layer was provided on one electrode substrate,
A liquid crystal element of the present invention was constructed in the same manner as in Reference Example 1 except that an alignment control film (400 layers) made of polyvinyl alcohol was provided on the other electrode substrate.
尚、本実施例で用いた４００人の一方のポリビニルアル
コール膜の比抵抗をＡＳＴＭ Ｄ−２５７に従って測定
したところ、ρ＝１０６Ω、ｃｍであワた。Incidentally, when the specific resistance of one of the polyvinyl alcohol membranes of 400 people used in this example was measured according to ASTM D-257, it was found to be ρ=10 6 Ω, cm.
上記素子を実施例２およびと同様に駆動したところ、同
様な結果が得られた。When the above device was driven in the same manner as in Example 2, similar results were obtained.
第１図〜第４図は強誘電性液晶素子の断面の１部を図解
的に示し、且つ液晶分子の分極の二つの状態を図解的に
示す図であり、第５図は本発明の強誘電性液晶素子の断
面を図解的に示す図であり、第６図は本発明の素子と参
考例の素子との飽和電圧と放置時間との関係を示す図で
ある。
ｌ、１′・一基板
２・・・液晶層
３・一液晶分子
４・・・双極子モーメント
５．５′・・・液晶分子の配向状態
６・−絶縁層
７・−電極
８・・・プラスイオン
９・−マイナスイオン
特許出願人 キャノン株式会社
代理人 弁理士 吉 １）勝 広、、。
第１図
第２図
第５図FIGS. 1 to 4 schematically show a part of the cross section of a ferroelectric liquid crystal element, and also diagrammatically show two states of polarization of liquid crystal molecules, and FIG. FIG. 6 is a diagram schematically showing a cross section of a dielectric liquid crystal device, and FIG. 6 is a diagram showing the relationship between saturation voltage and standing time of the device of the present invention and a device of a reference example. l, 1'・One substrate 2...Liquid crystal layer 3・One liquid crystal molecule 4...Dipole moment 5.5'...Orientation state of liquid crystal molecules 6・-Insulating layer 7・-Electrode 8... Positive Ion 9 - Negative Ion Patent Applicant Canon Co., Ltd. Agent Patent Attorney Yoshi 1) Hiro Katsut... Figure 1 Figure 2 Figure 5
Claims (12)
層に接する面のいずれか一方を導電性としたことを特徴
とする強誘電性液晶素子。(1) A ferroelectric liquid crystal element characterized in that one of the surfaces of two electrode substrates sandwiching a ferroelectric liquid crystal layer in contact with the liquid crystal layer is electrically conductive.
囲第（１）項に記載の強誘電性液晶素子。(2) A ferroelectric liquid crystal device according to claim (1), wherein an insulating layer is provided only on one substrate surface.
くとも一方に配向制御膜を設けた特許請求の範囲第（１
）項に記載の強誘電性液晶素子。(3) Claim No. 1 in which an alignment control film is provided on at least one of the surfaces of the two electrode substrates in contact with the ferroelectric liquid crystal layer.
) The ferroelectric liquid crystal element described in item 1.
求の範囲第（３）項に記載の強誘電性液晶素子。(4) The ferroelectric liquid crystal element according to claim (3), wherein the alignment control film is subjected to a rubbing treatment.
下である特許請求の範囲第（３）項または第（４）項に
記載の強誘電性液晶素子。(5) The conductivity of the alignment control film is ρ=10^6Ω. The ferroelectric liquid crystal element according to claim 3 or 4, wherein the ferroelectric liquid crystal element has a diameter of 1 cm or less.
下である特許請求の範囲第（３）項または第（４）項に
記載の強誘電性液晶素子。(6) The conductivity of the alignment control film is ρ=10^4Ω. The ferroelectric liquid crystal element according to claim 3 or 4, wherein the ferroelectric liquid crystal element has a diameter of 1 cm or less.
且つ他方の電極基板が絶縁層を有することなく導電性が
ρ＝１０＾６Ω．ｃｍ以下の配向制御膜を有する特許請
求の範囲第（１）項に記載の強誘電性液晶素子。(7) one electrode substrate has an insulating layer and an alignment control film;
In addition, the other electrode substrate does not have an insulating layer and has a conductivity of ρ=10^6Ω. The ferroelectric liquid crystal element according to claim (1), which has an alignment control film with a thickness of less than cm.
ド、ポリアミド、ポリエステルイミド、セルロースまた
はポリエチレンから形成されている特許請求の範囲第（
３）項〜第（７）項に記載の強誘電性液晶素子。(8) The alignment control film is made of polyvinyl alcohol, polyimide, polyamide, polyesterimide, cellulose, or polyethylene.
The ferroelectric liquid crystal device according to items 3) to 7).
る特許請求の範囲第（１）項に記載の強誘電性液晶素子
。(9) The ferroelectric liquid crystal element according to claim (1), wherein the ferroelectric liquid crystal is a chiral smectic liquid crystal.
スメクチック液晶のらせん構造を消失させるのに十分な
薄い膜厚に設定されている特許請求の範囲第（９）項に
記載の強誘電性液晶素子。(10) The ferroelectric liquid crystal element according to claim (9), wherein the thickness of the chiral smectic liquid crystal is set to be thin enough to eliminate the helical structure of the chiral smectic liquid crystal.
晶層に接する面のいずれか一方を導電性とした強誘電性
液晶素子において、素子の非表示時に直流電界を印加す
ることを特徴とする強誘電性液晶素子の駆動方法。(11) In a ferroelectric liquid crystal element in which one of the surfaces in contact with the liquid crystal layer of two electrode substrates sandwiching a ferroelectric liquid crystal layer is conductive, it is possible to apply a DC electric field when the element is not displaying information. Characteristic driving method for ferroelectric liquid crystal elements.
る電界を打ち消す方向である特許請求の範囲第（１１）
項に記載の強誘電性液晶素子の駆動方法。(12) Claim No. 11, wherein the applied DC electric field is in a direction that cancels the electric field due to spontaneous polarization of the liquid crystal molecules.
A method for driving a ferroelectric liquid crystal element described in 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61278743A JPH0711632B2 (en) | 1986-11-25 | 1986-11-25 | Voltage application method for chiral smectic liquid crystal device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61278743A JPH0711632B2 (en) | 1986-11-25 | 1986-11-25 | Voltage application method for chiral smectic liquid crystal device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63132220A true JPS63132220A (en) | 1988-06-04 |
| JPH0711632B2 JPH0711632B2 (en) | 1995-02-08 |
Family
ID=17601584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61278743A Expired - Fee Related JPH0711632B2 (en) | 1986-11-25 | 1986-11-25 | Voltage application method for chiral smectic liquid crystal device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0711632B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0374865A2 (en) * | 1988-12-22 | 1990-06-27 | Hoechst Aktiengesellschaft | Ferroelectric liquid-crystal shutter and display element with an attenuated optical hysterisis |
| JPH09151450A (en) * | 1995-11-24 | 1997-06-10 | Ohbayashi Corp | Construction method for earth retaining wall |
| EP1043618A1 (en) * | 1998-10-22 | 2000-10-11 | Citizen Watch Co., Ltd. | Ferroelectric liquid crystal display, and its driving method |
| JP2012247663A (en) * | 2011-05-30 | 2012-12-13 | Seiko Epson Corp | Liquid crystal device, projection type display device, and electronic appliance |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59214824A (en) * | 1983-05-20 | 1984-12-04 | Seiko Epson Corp | Liquid-crystal electrooptic device |
| JPS6330829A (en) * | 1986-07-25 | 1988-02-09 | Seiko Epson Corp | Manufacture of liquid crystal display device |
| JPS63121020A (en) * | 1986-11-10 | 1988-05-25 | Canon Inc | Ferroelectric liquid crystal element |
-
1986
- 1986-11-25 JP JP61278743A patent/JPH0711632B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59214824A (en) * | 1983-05-20 | 1984-12-04 | Seiko Epson Corp | Liquid-crystal electrooptic device |
| JPS6330829A (en) * | 1986-07-25 | 1988-02-09 | Seiko Epson Corp | Manufacture of liquid crystal display device |
| JPS63121020A (en) * | 1986-11-10 | 1988-05-25 | Canon Inc | Ferroelectric liquid crystal element |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0374865A2 (en) * | 1988-12-22 | 1990-06-27 | Hoechst Aktiengesellschaft | Ferroelectric liquid-crystal shutter and display element with an attenuated optical hysterisis |
| JPH09151450A (en) * | 1995-11-24 | 1997-06-10 | Ohbayashi Corp | Construction method for earth retaining wall |
| EP1043618A1 (en) * | 1998-10-22 | 2000-10-11 | Citizen Watch Co., Ltd. | Ferroelectric liquid crystal display, and its driving method |
| EP1043618A4 (en) * | 1998-10-22 | 2005-08-31 | Citizen Watch Co Ltd | Ferroelectric liquid crystal display, and its driving method |
| JP2012247663A (en) * | 2011-05-30 | 2012-12-13 | Seiko Epson Corp | Liquid crystal device, projection type display device, and electronic appliance |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0711632B2 (en) | 1995-02-08 |
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