JPH0786605B2 - Liquid crystal device - Google Patents
Liquid crystal deviceInfo
- Publication number
- JPH0786605B2 JPH0786605B2 JP59143481A JP14348184A JPH0786605B2 JP H0786605 B2 JPH0786605 B2 JP H0786605B2 JP 59143481 A JP59143481 A JP 59143481A JP 14348184 A JP14348184 A JP 14348184A JP H0786605 B2 JPH0786605 B2 JP H0786605B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- electrode
- signal
- pulse
- scan
- 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
Links
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
- G02F1/13781—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 using smectic liquid crystals
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
- G09G2310/0202—Addressing of scan or signal lines
- G09G2310/0205—Simultaneous scanning of several lines in flat panels
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/06—Details of flat display driving waveforms
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0209—Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/2007—Display of intermediate tones
- G09G3/2018—Display of intermediate tones by time modulation using two or more time intervals
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Liquid Crystal (AREA)
- Liquid Crystal Display Device Control (AREA)
Description
【発明の詳細な説明】 本発明は、強誘電性を発現するカイラルスメクチック液
晶を用いた液晶装置に関する。The present invention relates to a liquid crystal device using a chiral smectic liquid crystal exhibiting ferroelectricity.
従来より、走査電極群と信号電極群をマトリクス状に構
成し、その電極間に液晶化合物を充填し、多数の画素を
形成して画像或いは情報の表示を行う液晶表示素子は、
よく知られている。この表示素子の駆動法としては、走
査電極群に、順次、周期的にアドレス信号を選択印加
し、信号電極群には所定の情報信号をアドレス信号と同
期させて並列的に選択印加する時分割駆動が採用されて
いるが、この表示素子及びその駆動法は、以下に述べる
如き致命的とも言える大きな欠点を有していた。Conventionally, a liquid crystal display element configured to form a scan electrode group and a signal electrode group in a matrix shape, fill a liquid crystal compound between the electrodes, and form a large number of pixels to display an image or information,
well known. As a method of driving this display element, a time division in which an address signal is sequentially and cyclically selected and applied to the scanning electrode group and a predetermined information signal is selectively applied in parallel to the signal electrode group in synchronization with the address signal. Although driving is adopted, this display element and its driving method have a serious drawback that can be said to be fatal as described below.
即ち、画素密度を高く、或いは画面を大きくするのが難
しいことである。従来の液晶の中で応答速度が比較的高
く、しかも消費電力が小さいことから、表示素子として
実用に供されているのは殆んどが、例えば、M.Schadtと
W.Helfrich著、“Applied Physics"Letters"、Vol.18,N
o.4（1971.2.15）、P.127〜128の“Voltage−Dependent
Optical Activity of a Twisted Nematic Liquid Crys
tal"に示されたTN（twisted nematic）型の液晶を用い
たものであり、この型の液晶は、無電界状態で正の誘電
異方性をもつ、ネマチツク液晶の分子が、液晶層厚方向
で捩れた構造（ヘリカル構造）を形成し、両電極面でこ
の液晶の分子が互いに並行に配列した構造を形成してい
る。一方、電界印加状態では、正の誘電異方性をもつネ
マチツク液晶が電界方向に配列し、この結果光調変調を
起すことができる。この型の液晶を用いてマトリクス電
極構造によつて表示素子を構成した場合、走査電極と信
号電極が共に選択される領域（選択点）には、液晶分子
を電極面に垂直に配列させるに要する閾値以上の電圧が
印加され、走査電極と信号電極が共に選択されない領域
（非選択点）には電圧は印加されず、したがつて液晶分
子は電極面に対して並行な安定配列を保つている。この
ような液晶セルの上下に、互いにクロスニコル関係にあ
る直線偏光子を配置することにより、選択点では光が透
過せず、非選択点では光が透過するため、画像素子とす
ることが可能となる。然し乍ら、マトリクス電極構造を
構成した場合には、走査電極が選択され、信号電極が選
択されない領域或いは、走査電極が選択されず、信号電
極が選択される領域（所謂“半選択点”）にも有限の電
界がかかつてしまう。選択点にかかる電圧と、半選択点
にかかる電圧の差が充分に大きく、液晶分子を電界に垂
直に配列させるに要する電圧閾値がこの中間の電圧値に
設定されるならば、表示素子は正常に動作するかけであ
る。しかし、この方式において、走査線数（Ｎ）を増や
して行つた場合、画面全体（１フレーム）を走査する間
に一つの選択点に有効な電界がかかつている時間（duty
比）は、1/Nの割合で減少してしまう。このために、く
り返し走査を行つた場合の選択点と比選択点にかかる実
効値としての電圧差は、走査線数が増えれば増える程小
さくなり、結果的には画像コントラストの低下やクロス
トークが避け難い欠点となつている。このような現像
は、双安定性を有さない液晶（電極面に対し、液晶分子
が水平に配向しているのが安定状態であり、電界が有効
に印加されている間のみ垂直に配向する）を、時間的蓄
積効果を利用して駆動する（即ち、繰り返し走査する）
ときに生じる本質的には避け難い問題点である。この点
を改良するために、電圧平均化法、２周波駆動法や多重
マトリクス法等が既に提案されているが、いずれの方法
でも不充分であり、表示素子の大画面化や高密度化は、
走査線数が充分に増やせないことによつて頭打ちになつ
ているのが現状である。That is, it is difficult to increase the pixel density or enlarge the screen. Among the conventional liquid crystals, most of them are practically used as display devices because of their relatively high response speed and low power consumption. For example, M.Schadt
W. Helfrich, “Applied Physics“ Letters ”, Vol.18, N
o.4 (1971.2.15), P.127-128 "Voltage-Dependent"
Optical Activity of a Twisted Nematic Liquid Crys
The TN (twisted nematic) type liquid crystal shown in "tal" is used. This type of liquid crystal has nematic liquid crystal molecules that have positive dielectric anisotropy in the absence of electric field Form a twisted structure (helical structure) in which molecules of the liquid crystal are aligned in parallel to each other on both electrode surfaces.On the other hand, a nematic liquid crystal having a positive dielectric anisotropy in an electric field applied state. Are arranged in the direction of the electric field, and as a result, light modulation can occur.When a display element is formed by a matrix electrode structure using this type of liquid crystal, a region (where both the scanning electrode and the signal electrode are selected) The voltage above the threshold required to align the liquid crystal molecules perpendicularly to the electrode surface is applied to the selection point), and no voltage is applied to the region (non-selection point) in which neither the scanning electrode nor the signal electrode is selected. The liquid crystal molecules are parallel to the electrode surface. By arranging linear polarizers having a crossed Nicol relationship above and below such a liquid crystal cell, light does not pass at selected points and light passes at non-selected points. However, in the case where the matrix electrode structure is formed, the area where the scanning electrode is selected and the signal electrode is not selected, or the area where the scanning electrode is not selected and the signal electrode is selected is possible. A finite electric field is also applied to the so-called “half-selection point.” The voltage required to align liquid crystal molecules perpendicularly to the electric field is large enough that the difference between the voltage applied to the selection point and the voltage applied to the half-selection point is sufficiently large. If the threshold value is set to this intermediate voltage value, the display element is supposed to operate normally.However, in this method, when the number of scanning lines (N) is increased, the whole screen (one frame) is displayed. To Time effective electric field to one of the selected points are KaKatsu during the 査 (duty
Ratio) will decrease at a rate of 1 / N. For this reason, the voltage difference as an effective value applied to the selection point and the ratio selection point in the case of performing repeated scanning becomes smaller as the number of scanning lines increases, and as a result, lowering of image contrast and crosstalk occur. This is an inevitable drawback. In such development, a liquid crystal having no bistability (a stable state in which liquid crystal molecules are horizontally aligned with respect to an electrode surface, and vertically aligned only while an electric field is effectively applied) ) Is driven by utilizing the temporal accumulation effect (that is, repeatedly scanned).
It is an inherently unavoidable problem that sometimes occurs. In order to improve this point, a voltage averaging method, a two-frequency driving method, a multiple matrix method, etc. have already been proposed, but none of them is sufficient, and it is not possible to increase the screen size and density of the display element. ,
The current situation is that the number of scanning lines cannot be increased enough to reach the ceiling.
本発明の目的は、改善された駆動特性を持つ新規な液晶
装置を提供することにある。It is an object of the present invention to provide a new liquid crystal device having improved driving characteristics.
本発明は、 a.間隔を置いて交差した走査電極と信号電極ととで構成
したマトリックス電極、及び該走査電極と情報電極との
間に配置され、印加電圧の極性に応じて一方の配向状態
と他方の配向状態との何れか一方を生じさせるカイラル
スメクチック液晶を備えた画面を有する液晶パネル、及
び b.第一の順次走査期間で走査電極に、順次、一方極性パ
ルスを有する第一走査パルスを印加し、該一方極性パル
スの走査電極への印加と同期して、信号電極に、同時
に、一方の配向状態を生じさせるのに十分な電圧をカイ
ラルスメクチック液晶に印加される様に、電圧信号を印
加することによって、画面をクリヤした後、 第二の順次走査期間で走査電極に、順次、他方極性パル
スを有する第二走査パルスを印加し、該他方極性パルス
の走査電極への印加と同期して、信号電極に、選択的
に、他方の配向状態を生じさせるのに十分な電圧がカイ
ラルスメクチック液晶に印加される様に、情報パルスを
印加することによって、情報に応じた書込み画面を形成
する手段を有する液晶装置に特徴がある。The present invention includes: a. A matrix electrode composed of scan electrodes and signal electrodes that intersect at a distance, and one alignment state depending on the polarity of an applied voltage, which is arranged between the scan electrodes and the information electrodes. And a liquid crystal panel having a screen having a chiral smectic liquid crystal that causes one of the other alignment states, and b. A first scanning pulse having one polarity pulse sequentially on the scanning electrodes in the first sequential scanning period. Voltage signal is applied to the chiral smectic liquid crystal simultaneously with the application of the one-polarity pulse to the scan electrode, and simultaneously with the signal electrode, a voltage sufficient to generate one alignment state is applied to the signal electrode. After clearing the screen by applying, the second scan pulse having the other polarity pulse is sequentially applied to the scan electrodes in the second sequential scan period, and the other polarity pulse is applied to the scan electrodes. In synchronism with the application of the information, by writing an information pulse to the signal electrode so that a voltage sufficient to cause the other alignment state is selectively applied to the chiral smectic liquid crystal, writing according to information is performed. The liquid crystal device having a means for forming a screen is characteristic.
本発明の駆動法で用いることができる双安定性を有する
液晶としては、強誘電性を有するカイラルスメクテイツ
ク液晶が最も好ましく、そのうちカイラルスメクテイツ
クＣ相（SmCx）又はＨ相（SmHx）の液晶が適している。
この強誘電性液晶については、“LE JOURNAL DE PHYSIQ
UE LETTERS"36（Ｌ−69）1975,「Ferroelectric Liquid
Crystals」；“Applied Physics Letters"36（11）198
0、「Submicro Second BistablelE ectrooptic Switchi
ng in Liquid Crystals」；“固体物理”16（141）1981
「液晶」等に記載されており、本発明ではこれらに開示
された強電性液晶を用いることができる。As a liquid crystal having bistability that can be used in the driving method of the present invention, a chiral smectic liquid crystal having ferroelectricity is most preferable, and among them, a chiral smectic C phase (SmC x ) or an H phase (SmH x ) Liquid crystal is suitable.
For this ferroelectric liquid crystal, refer to "LE JOURNAL DE PHYSIQ
UE LETTERS " 36 (L-69) 1975," Ferroelectric Liquid
Crystals ”;“ Applied Physics Letters ” 36 (11) 198
0, `` Submicro Second BistablelE ectrooptic Switchi
ng in Liquid Crystals ”;“ Solid State Physics ” 16 (141) 1981
As described in “Liquid crystal” and the like, in the present invention, the strong electric liquid crystal disclosed therein can be used.
より具体的には、本発明法に用いられる強誘電性液晶化
合物の例としては、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（DOBAMBC）、ヘ
キシルオキシベンジリデン−Ｐ′−アミノ−２−クロロ
プロピルシンナメート（HOBACPC）および４−ｏ−（２
−メチル）−ブチルレゾルシリデン−４′−オクチルア
ニリン（MBRA8）等が挙げられる。More specifically, examples of the ferroelectric liquid crystal compound used in the method of the present invention include desiloxybenzylidene-P'-amino-2-methylbutylcinnamate (DOBAMBC) and hexyloxybenzylidene-P'-amino-. 2-chloropropyl cinnamate (HOBACPC) and 4-o- (2
-Methyl) -butyl resorcylidene-4'-octylaniline (MBRA8) and the like.
これらの材料を用いて、素子を構成する場合、液晶化合
物が、SmCx相又はSmHx相となるような温度状態に保持す
る為、必要に応じて素子をヒーターが埋め込まれた銅ブ
ロツク等により支持することができる。When a device is formed using these materials, the liquid crystal compound is kept at a temperature state such that the liquid crystal compound becomes the SmC x phase or the SmH x phase. Can be supported.
第１図は、強誘電性液晶セルの例を模式的に描いたもの
である。11と11′は、In2O3、SnO2やITO（Indium−Tin
Oxide）等の透明電極がコートされた基板（ガラス板）
であり、その間に液晶分子層12がガラス面に垂直になる
ように配向したSmCx相の液晶が封入されている。太線で
示した線13が液晶分子を表わしており、この液晶分子13
は、その分子に直交した方向に双極子モーメント（Ｐ
⊥）14を有している。基板11と11′上の電極間に一定の
値以上の電圧を印加すると、液晶分子13のらせん構造
がほどけ、双極子モーメント（Ｐ⊥）14はすべて電界方
向に向くよう、液晶分子13の配向方向を変えることがで
きる。液晶分子13は細長い形状を有しており、その長軸
方向と短軸方向で屈折率異方性を示し、従つて例えばガ
ラス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、電圧印加極性によつて光学特性が変
わる液晶光学変調素子となることは、容易に理解され
る。さらに液晶セルの厚さを充分に薄くした場合（例え
ば１μ）には、第２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）その双極子モーメントＰ又はＰ′は上向き（24）
又は下向（24）′のどちらかの状態をとる。このような
セルに第２図に示す如く一定の閾値以上の極性の異る電
界Ｅ又はＥ′を付与すると、双極子モーメント電界Ｅ又
はＥ′はの電界ベクトルに対応して上向き24又は、下向
き24′と向きを変え、それに応じて液晶分子は第１の安
定状態23かあるいは第２の安定状態23′の何れか１方に
配向する。FIG. 1 schematically shows an example of a ferroelectric liquid crystal cell. 11 and 11 ′ are In 2 O 3 , SnO 2 and ITO (Indium-Tin
Substrate (glass plate) coated with transparent electrodes such as Oxide)
The liquid crystal of the SmC x phase oriented so that the liquid crystal molecular layer 12 is perpendicular to the glass surface is enclosed between them. The thick line 13 represents a liquid crystal molecule.
Is the dipole moment (P
⊥) 14 When a voltage of a certain value or more is applied between the electrodes on the substrates 11 and 11 ', the helical structure of the liquid crystal molecules 13 is unraveled, and all the dipole moments (P⊥) 14 are oriented in the electric field direction. You can change direction. The liquid crystal molecules 13 have an elongated shape, and exhibit refractive index anisotropy in the major axis direction and the minor axis direction thereof, so that, for example, polarizers arranged in a crossed Nicols position above and below a glass surface should be placed. For example, it is easy to understand that the liquid crystal optical modulation element has optical characteristics that change depending on the polarity of voltage application. Further, when the thickness of the liquid crystal cell is made sufficiently thin (for example, 1 μ), the helical structure of the liquid crystal molecules is unwound (non-helical structure) even when no electric field is applied, as shown in FIG. Moment P or P'upward (24)
Or, it is either in the downward direction (24) '. When an electric field E or E'having a polarity different from a certain threshold value is applied to such a cell as shown in FIG. 2, the dipole moment electric field E or E'is directed upward 24 or downward depending on the electric field vector of. 24 ', and the liquid crystal molecules are oriented to either the first stable state 23 or the second stable state 23' accordingly.
このような強誘電性液晶を光学変調素子として用いるこ
との利点は２つある。第１に、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を有することであ
る。第２の点を、例えば第２図によつて説明すると、電
界Ｅを印加すると液晶分子は第１の安定状態23に配向す
るが、この状態は電界を切つても安定である。又、逆向
きの電界Ｅ′を印加すると、液晶分子は第２の安定状態
23′に配向して、その分子の向きを変えるが、やはり電
界を切つてもこの状態に留つている。又、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、セルとしては出来るだ
け薄い方が好ましく、一般的には、0.5μ〜20μ、特に
１μ〜５μが適している。この種の強誘電性液晶を用い
たマトリクス電極構造を有する液晶−電気光学装置は、
例えばクラークとラガバルにより、米国特許第4367924
号明細書で提案されている。There are two advantages of using such a ferroelectric liquid crystal as an optical modulation element. Firstly, the response speed is extremely fast, and secondly, the alignment of liquid crystal molecules has bistability. The second point will be explained with reference to FIG. 2, for example. When an electric field E is applied, the liquid crystal molecules are aligned in the first stable state 23, but this state is stable even when the electric field is cut off. When an electric field E'in the opposite direction is applied, the liquid crystal molecules are in the second stable state.
It is oriented to 23 'and changes the orientation of the molecule, but it remains in this state even when the electric field is cut off. Also, the applied electric field E
As long as the values do not exceed a certain threshold, they are still maintained in their respective orientations. In order to effectively realize such a high response speed and bistability, it is preferable that the cell is as thin as possible, and generally 0.5 μ to 20 μ, particularly 1 μ to 5 μ is suitable. A liquid crystal-electro-optical device having a matrix electrode structure using this type of ferroelectric liquid crystal,
For example, Clark and Ragabal, U.S. Pat.
No. specification.
本発明の駆動法の好ましい具体例を、図面を用いて説明
する。A preferred specific example of the driving method of the present invention will be described with reference to the drawings.
第３図は、中間に強誘電性液晶化合物（図示せず）が挾
まれたマトリクス電極構造を有するセル31の電極の模式
配置図である。32は走査電極群であり、33は信号電極群
である。FIG. 3 is a schematic layout diagram of electrodes of a cell 31 having a matrix electrode structure in which a ferroelectric liquid crystal compound (not shown) is sandwiched in the middle. 32 is a scanning electrode group, and 33 is a signal electrode group.
第４図（ａ）と（ｂ）は、それぞれ選択時の走査信号と
それ以外の非選択時の走査信号を示している。FIGS. 4 (a) and 4 (b) show the scanning signal at the time of selection and the scanning signal at the time of other non-selection, respectively.
第４図（ｃ）と（ｄ）は、それぞれ強誘電性液晶の双安
定性のうち第１の安定状態に配向させる電気信号（白信
号という）と双安定性のうち第２の安定状態に配向させ
る電気信号（黒信号という）を示している。FIGS. 4 (c) and 4 (d) respectively show an electric signal (referred to as a white signal) for orienting the ferroelectric liquid crystal to the first stable state and a second stable state for the bistability. An electrical signal for orientation (referred to as a black signal) is shown.
まず、本発明の駆動法は、第５図に示す様に第１フレー
ムF1（第一の順次走査期間）で走査電極群32の全部又は
一部に走査信号を印加し、これと同期させて信号電極群
33の全部又は一部に白信号を印加する。次の第２フレー
ムF2（第二の順次走査期間）で例えば第３図に示す如く
所定の個所（図中の黒部で示す画素）に黒信号を印加す
る。この時の走査電極群32（321,322,323,324,325）及
び信号電極群33（331,332,333,334,335）に印加する電
気信号と第３図中の画素ＡとＢに印加される電圧波形を
第５図で明らかにしている。First, according to the driving method of the present invention, as shown in FIG. 5, a scanning signal is applied to all or a part of the scanning electrode group 32 in the first frame F 1 (first sequential scanning period) and synchronized with this. Signal electrode group
A white signal is applied to all or part of 33. In the next second frame F 2 (second sequential scanning period), for example, a black signal is applied to a predetermined portion (pixel shown by a black portion in the drawing) as shown in FIG. FIG. 5 clarifies the electric signals applied to the scanning electrode group 32 (321, 322, 323, 324, 325) and the signal electrode group 33 (331, 332, 333, 334, 335) and the voltage waveforms applied to the pixels A and B in FIG. 3 at this time.
以上に於て、電圧値VoはVo＜Vth1＜2Voと−Vo＞Vth2＞
−2Voを満足する所望の値に設定されている。従つて、
第５図から明らかな様に選択時の走査信号が印加された
走査電極に対応する全画素（又は部分書き換えの時は書
き換え対象の画素）には位相t1で−2Voの電圧が印加さ
れることになり、強誘電性液晶は第１の安定状態に配向
し、位相t2では画素に印加される電圧がVoとなるが、Vo
＜Vth1となつているため位相t1で配向した第１の安定状
態（「白」）が維持されることになる。この様に第１フ
レームF1で一担全画素を白信号によつて「白」に消去さ
れる。そして、第２フレームF2で所定の画素のみに走査
信号と同期させて信号電極に黒信号印加することによつ
て、黒白の一画面が形成される。この際黒信号が印加さ
れた画素では位相▲ｔ1 1▼で−2Voが印加された後位相
▲ｔ1 2▼で2Voが印加され、2Vo＞Vth1となつているた
め、位相▲ｔ1 1▼では第１の安定状態に配向していた強
誘電性液晶が位相▲ｔ1 2▼で第２の安定状態に配向され
て「黒」になる。In the above, the voltage value Vo is Vo <Vth 1 <2Vo and −Vo> Vth 2 >
It is set to the desired value that satisfies −2Vo. Therefore,
As is apparent from FIG. 5, a voltage of −2Vo is applied at phase t 1 to all pixels (or pixels to be rewritten in the case of partial rewriting) corresponding to the scanning electrodes to which the scanning signal at the time of selection is applied. will be, the ferroelectric liquid crystal is oriented in the first stable state, the voltage applied to the pixel at the phase t 2 becomes Vo, Vo
Since <Vth 1 , the first stable state (“white”) oriented at the phase t 1 is maintained. In this way, in the first frame F 1 , all the responsible pixels are erased to “white” by the white signal. Then, Yotsute to black signal applied to the scanning signal synchronized with not the signal electrodes only to a predetermined pixel in the second frame F 2, the initial screen of the black and white is formed. In the pixel cyclo signal is applied is phase ▲ t 1 2 in ▼ 2Vo is applied after the application of -2Vo is in phase ▲ t 1 1 ▼, 2Vo> Vth 1 and for that summer, the phase ▲ t 1 In 1) , the ferroelectric liquid crystal that was oriented in the first stable state is oriented in the second stable state at phase {tilde over (t) 1 2 } and becomes "black".
この際、電圧値Ｖの値及び位相（t1＋t2）＝Ｔの値とし
ては、用いられる液晶材料やセルの厚さにも依存する
が、通常３ボルト〜70ボルトで、0.1μsec〜2msecの範
囲で用いられる。At this time, the value of the voltage value V and the value of the phase (t 1 + t 2 ) = T depend on the liquid crystal material used and the thickness of the cell, but are usually 3 V to 70 V, 0.1 μsec to 2 msec. Used in the range of.
本発明の駆動方法が有効に達成されるためには、走査電
極或いは信号電極に与えられる電気信号が、必ずしも第
５図に於て説明されたような単純な矩形波信号でなくて
もよいことは自明である。例えば、正弦波や三角波によ
つて駆動することも可能である。In order to effectively achieve the driving method of the present invention, the electric signal applied to the scan electrode or the signal electrode does not necessarily have to be a simple rectangular wave signal as described with reference to FIG. Is self-evident. For example, it is possible to drive with a sine wave or a triangular wave.
第６図は、液晶一光シヤツタに応用した時のマトリクス
電極構造の模式図が示されている。この際、61は画素で
あつて、この部分のみ両側の電極を透明なもので形成し
ている。62は走査電極群、63は信号電極群を表わしてい
る。FIG. 6 shows a schematic diagram of a matrix electrode structure when applied to a liquid crystal one-light shutter. At this time, 61 is a pixel, and the electrodes on both sides of this pixel are formed transparent. Reference numeral 62 represents a scanning electrode group, and 63 represents a signal electrode group.
今までに述べた本発明の説明に於ては、一つの画素に対
応する液晶化合物層は一様であり、一画素全領域に渉つ
てどちらかの安定状態に配向を揃えているものとして来
た。しかし乍ら、強誘電性液晶の配向状態は、基板の表
面との相互作用によつて極めて微妙に作用されるため、
印加電圧と閾値電圧Vth1又は−Vth2の差が小さい場合に
は、局所的な基板表面の僅かの差によつて、一画素内で
互い逆方向の安定配向状態が混在している状況が生じ得
る。これを利用して情報信号の第２の位相に於て階調性
を与える信号を付加することが可能である。例えば、第
５図に於て述べた駆動方法と走査信号は全く同一にして
第７図（ａ）〜（ｄ）に示すような階調に応じ、信号電
極に印加する情報信号の位相t2に於けるパルス数を換え
ることによつて階調画像を得ることが可能である。In the above description of the present invention, it is assumed that the liquid crystal compound layer corresponding to one pixel is uniform, and the alignment is aligned in either stable state across the entire area of one pixel. It was However, since the alignment state of the ferroelectric liquid crystal is very delicately affected by the interaction with the surface of the substrate,
When the difference between the applied voltage and the threshold voltage Vth 1 or −Vth 2 is small, there is a situation where stable alignment states in opposite directions are mixed in one pixel due to a slight difference in the substrate surface locally. Can happen. By utilizing this, it is possible to add a signal that imparts gradation in the second phase of the information signal. For example, the driving method described in FIG. 5 and the scanning signal are exactly the same, and the phase t 2 of the information signal applied to the signal electrode is changed according to the gradation as shown in FIGS. It is possible to obtain a gradation image by changing the number of pulses in.
又、基板処理として自然発生的に生ずる基板表面状態の
ばらつきを利用するのみならず、人為的に、例えば、微
少モザイクパターンを有する基板表面状態を利用するこ
とも可能である。Further, it is possible not only to utilize the variation in the substrate surface state that occurs spontaneously as the substrate processing but also to artificially utilize the substrate surface state having a minute mosaic pattern, for example.
本発明の方法は、液晶一光シヤツタや液晶テレビなどの
光学シヤツタあるいはデイスプレイ分野に広く応用する
ことができる。INDUSTRIAL APPLICABILITY The method of the present invention can be widely applied to the fields of optical shutters such as liquid crystal single-light shutters and liquid crystal televisions, or display fields.
第１図は、カイラルスメクテイツク相液晶を有する液晶
素子を、模式的に示す斜視図である。第２図は、本発明
法で用いる液晶素子の双安定性を模式的に示す斜視図で
ある。 第３図は、本発明の駆動法に用いる液晶素子の電極配列
状態を模式的に示す平面図である。第４図（ａ）〜
（ｄ）は、電気信号波形図である。第５図は、時系列で
示した電圧波形図である。第６図は、本発明の駆動法の
好ましい適用対象の１例としての液晶一光シヤツタの模
式平面図である。第７図は、本発明の別の具体例におけ
る電圧波形図である。第８図は、本発明の別の具体例に
おける電圧波形図である。FIG. 1 is a perspective view schematically showing a liquid crystal element having a chiral smectic phase liquid crystal. FIG. 2 is a perspective view schematically showing the bistability of the liquid crystal element used in the method of the present invention. FIG. 3 is a plan view schematically showing an electrode arrangement state of a liquid crystal element used in the driving method of the present invention. FIG. 4 (a)-
(D) is an electric signal waveform diagram. FIG. 5 is a voltage waveform diagram shown in time series. FIG. 6 is a schematic plan view of a liquid crystal one-optical shutter as an example of a preferred application of the driving method of the present invention. FIG. 7 is a voltage waveform diagram in another example of the present invention. FIG. 8 is a voltage waveform diagram in another example of the present invention.
Claims (1)
極ととで構成したマトリックス電極、及び該走査電極と
情報電極との間に配置され、印加電圧の極性に応じて一
方の配向状態と他方の配向状態との何れか一方を生じさ
せるカイラルスメクチック液晶を備えた画面を有する液
晶パネル、及び b.第一の順次走査期間で走査電極に、順次、一方極性パ
ルスを有する第一走査パルスを印加し、該一方極性パル
スの走査電極への印加と同期して、信号電極に、同時
に、一方の配向状態を生じさせるのに十分な電圧をカイ
ラルスメクチック液晶に印加される様に、電圧信号を印
加することによって、画面をクリヤした後、 第二の順次走査期間で走査電極に、順次、他方極性パル
スを有する第二走査パルスを印加し、該他方極性パルス
の走査電極への印加と同期して、信号電極に、選択的
に、他方の配向状態を生じさせるのに十分な電圧がカイ
ラルスメクチック液晶に印加される様に、情報パルスを
印加することによって、情報に応じた書込み画面を形成
する手段を有する液晶装置。1. A matrix electrode composed of a scanning electrode and a signal electrode intersecting with each other at a distance, and one orientation depending on the polarity of an applied voltage, which is arranged between the scanning electrode and the information electrode. Liquid crystal panel having a screen including a chiral smectic liquid crystal that causes one of the two states and the other alignment state, and b. A first scan having one polarity pulse sequentially on the scan electrodes in the first sequential scan period. In order to apply a pulse to the chiral smectic liquid crystal, a voltage sufficient to generate one alignment state is simultaneously applied to the signal electrode in synchronization with the application of the pulse of one polarity to the scan electrode. After clearing the screen by applying a signal, a second scan pulse having the other polarity pulse is sequentially applied to the scan electrodes in the second sequential scan period, and the other polarity pulse is applied to the scan electrodes. In synchronism with the application of the information, by writing an information pulse to the signal electrode so that a voltage sufficient to cause the other alignment state is selectively applied to the chiral smectic liquid crystal, writing according to information is performed. A liquid crystal device having means for forming a screen.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59143481A JPH0786605B2 (en) | 1984-07-10 | 1984-07-10 | Liquid crystal device |
| US07/383,457 US5093737A (en) | 1984-02-17 | 1989-07-24 | Method for driving a ferroelectric optical modulation device therefor to apply an erasing voltage in the first step |
| US07/557,643 US5418634A (en) | 1983-04-19 | 1990-07-25 | Method for driving optical modulation device |
| US07/865,630 US5381254A (en) | 1984-02-17 | 1992-04-09 | Method for driving optical modulation device |
| US08/308,536 US5436743A (en) | 1984-02-17 | 1994-09-21 | Method for driving optical modulation device |
| US08/320,230 US5717419A (en) | 1984-02-17 | 1994-10-11 | Method for driving optical modulation device |
| US08/421,869 US5724059A (en) | 1984-02-17 | 1995-04-14 | Method for driving optical modulation device |
| US08/440,345 US5633652A (en) | 1984-02-17 | 1995-05-12 | Method for driving optical modulation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59143481A JPH0786605B2 (en) | 1984-07-10 | 1984-07-10 | Liquid crystal device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6122325A JPS6122325A (en) | 1986-01-30 |
| JPH0786605B2 true JPH0786605B2 (en) | 1995-09-20 |
Family
ID=15339702
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59143481A Expired - Fee Related JPH0786605B2 (en) | 1983-04-19 | 1984-07-10 | Liquid crystal device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0786605B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62278538A (en) * | 1986-05-26 | 1987-12-03 | Nec Corp | Driving method for liquid crystal element |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0629919B2 (en) * | 1982-04-16 | 1994-04-20 | 株式会社日立製作所 | Liquid crystal element driving method |
| JPS60123825A (en) * | 1983-12-09 | 1985-07-02 | Seiko Instr & Electronics Ltd | Liquid crystal display element |
-
1984
- 1984-07-10 JP JP59143481A patent/JPH0786605B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6122325A (en) | 1986-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS6245536B2 (en) | ||
| JPH0422496B2 (en) | ||
| JP2651204B2 (en) | Driving method of liquid crystal device | |
| JPS6243167B2 (en) | ||
| US5886678A (en) | Driving method for liquid crystal device | |
| US5381254A (en) | Method for driving optical modulation device | |
| JPH0434130B2 (en) | ||
| JPS6244247B2 (en) | ||
| JPH0535848B2 (en) | ||
| JPH079508B2 (en) | Liquid crystal display device and driving method thereof | |
| JP2507784B2 (en) | Liquid crystal device and driving method thereof | |
| JPS6246845B2 (en) | ||
| JPH0786605B2 (en) | Liquid crystal device | |
| JPS6249607B2 (en) | ||
| JP2584752B2 (en) | Liquid crystal device | |
| JPH0648333B2 (en) | Driving method of liquid crystal matrix display panel | |
| JP2614220B2 (en) | Display device | |
| JPH0422493B2 (en) | ||
| JPH0799415B2 (en) | Liquid crystal device | |
| JPH0448366B2 (en) | ||
| JPS6249608B2 (en) | ||
| JPH0823636B2 (en) | Driving method of optical modulator | |
| JPH0453293B2 (en) | ||
| JPH0434131B2 (en) | ||
| JPS6217732A (en) | Liquid crystal device and driving method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |