JP3166726B2 - Antiferroelectric liquid crystal optical element and driving method thereof - Google Patents
Antiferroelectric liquid crystal optical element and driving method thereofInfo
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- JP3166726B2 JP3166726B2 JP25805498A JP25805498A JP3166726B2 JP 3166726 B2 JP3166726 B2 JP 3166726B2 JP 25805498 A JP25805498 A JP 25805498A JP 25805498 A JP25805498 A JP 25805498A JP 3166726 B2 JP3166726 B2 JP 3166726B2
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- liquid crystal
- antiferroelectric liquid
- crystal cell
- optical axis
- optical element
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Description
【０００１】[0001]
【発明の属する技術分野】本発明は、文字、図形等を表
示する表示装置、入射光の透過量が変化する調光装置、
光シャッター等に利用される液晶光学素子に関し、更に
詳しくは反強誘電性液晶材料を用いた高コントラストの
反強誘電性液晶光学素子に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying characters, figures, etc., a dimming device in which the amount of transmission of incident light changes,
More particularly, the present invention relates to a high contrast antiferroelectric liquid crystal optical element using an antiferroelectric liquid crystal material.
【０００２】[0002]
【従来の技術】液晶ディスプレイは、薄型、軽量、低消
費電力という点で、ＣＲＴより有利なため、コンピュー
ター用のディスプレイ、あるいは携帯用のディスプレイ
として広く利用されている。ところで、現在利用されて
いる液晶ディスプレイには、ネマティック液晶が用いら
れている。ネマティック液晶は応答時間が速いもので２
０ｍｓ程と遅く、動画表示の点で、ＣＲＴより不利であ
る。2. Description of the Related Art Liquid crystal displays are more advantageous than CRTs in that they are thinner, lighter, and have lower power consumption, and are therefore widely used as computer displays or portable displays. By the way, a nematic liquid crystal is used for a currently used liquid crystal display. Nematic liquid crystal has a fast response time and is 2
It is as slow as 0 ms, which is disadvantageous from the CRT in displaying moving images.
【０００３】そこで、応答速度が遅いネマティック液晶
に代わって、高速応答が可能な液晶としてスメクティッ
ク液晶が期待されている。特に、R. B. Meyerらにより
報告された強誘電性液晶（J. Phys. （France） 36, L6
9 （1975））とA. D. L. Chandaniらにより報告された
反強誘電性液晶（Jpn. J. Appl. Phys., 28, L1265 （1
989））は自発分極を有し、電場印加時に自発分極と電
場との相互作用のため、１ｍｓ以下の高速応答が可能で
ある。Therefore, smectic liquid crystals are expected as liquid crystals capable of high-speed response, instead of nematic liquid crystals having a low response speed. In particular, ferroelectric liquid crystals reported by RB Meyer et al. (J. Phys. (France) 36, L6
9 (1975)) and the antiferroelectric liquid crystal reported by ADL Chandani et al. (Jpn. J. Appl. Phys., 28, L1265 (1
989)) has spontaneous polarization, and a high-speed response of 1 ms or less is possible due to the interaction between the spontaneous polarization and the electric field when an electric field is applied.
【０００４】強誘電性液晶の光スイッチング現象を利用
した光学素子として、表面安定化強誘電性液晶（ＳＳＦ
ＬＣ）光学素子が、N. A. Clark, S. T. Lagerwallによ
り提案されている（App. Phys. Lett., Vol.36, P.899
（1980））。ＳＳＦＬＣ光学素子は、印加電場に対し双
安定性を示し、２状態間の光学応答は高速（１ｍｓ以
下）という特徴を有している。ただし、双安定性のため
ＳＳＦＬＣ光学素子の電気光学応答は明状態と暗状態の
２つの状態のスイッチングに限定される。したがって、
電圧制御による中間調の表示は困難である。As an optical element utilizing the optical switching phenomenon of a ferroelectric liquid crystal, a surface stabilized ferroelectric liquid crystal (SSF) is used.
LC) optics have been proposed by NA Clark, ST Lagerwall (App. Phys. Lett., Vol. 36, P. 899).
(1980)). The SSFLC optical element has bistability with respect to an applied electric field, and has a feature that an optical response between two states is fast (1 ms or less). However, due to bistability, the electro-optical response of the SSFLC optical element is limited to switching between two states, a bright state and a dark state. Therefore,
It is difficult to display a halftone by voltage control.
【０００５】一方、反強誘電性液晶を利用した光学素子
が、A. D. L. Chandaniらにより提案されている（Jpn.
J. Appl. Phys., 29, 1757 （1990））。反強誘電性液
晶は、電場無印加時の反強誘電相と電場印加時の強誘電
相との電場誘起相転移に基づく３安定性を有し、３状態
間の光学応答はＳＳＬＦＣ光学素子と同様に高速（１ｍ
ｓ以下）という特徴を有している。この反強誘電性液晶
をバイアス電圧印加下にてスイッチングさせることによ
り、単純マトリクス方式での駆動が可能となる。また、
反強誘電相と強誘電相の共存状態を電圧制御することに
よる、単純マトリクス駆動での中間調表示がY. Yamamot
oらにより報告されている（Ferroelectrics, 149, 295
（1993））。On the other hand, an optical element using an antiferroelectric liquid crystal has been proposed by ADL Chandani et al. (Jpn.
J. Appl. Phys., 29, 1757 (1990)). The antiferroelectric liquid crystal has three stability based on an electric field induced phase transition between an antiferroelectric phase when no electric field is applied and a ferroelectric phase when an electric field is applied, and the optical response between the three states is the same as that of an SSLFC optical element. Similarly high speed (1m
s or less). By switching this antiferroelectric liquid crystal under the application of a bias voltage, driving in a simple matrix system becomes possible. Also,
Halftone display by simple matrix drive by voltage control of coexistence state of antiferroelectric phase and ferroelectric phase
(Ferroelectrics, 149, 295
(1993)).
【０００６】Y. Yamadaらにより反強誘電性液晶と単純
マトリクス駆動を組み合わせた、対角６インチのフルカ
ラー表示可能な反強誘電性液晶光学素子が報告されてい
る（SID’95 Digest, 791 （1995））。[0006] Y. Yamada et al. Reported an antiferroelectric liquid crystal optical element capable of displaying a full color of 6 inches diagonally by combining antiferroelectric liquid crystal and simple matrix driving (SID'95 Digest, 791 ( 1995)).
【０００７】しかし、この反強誘電性液晶光学素子で
は、ネマティック液晶とＴＦＴ駆動を組み合わせた素子
でのコントラストが１００以上あるのに比べ、コントラ
ストが３０と非常に小さい。これは暗状態での反強誘電
性液晶の前駆現象による光漏れが原因である。前駆現象
とは、反強誘電相から強誘電相へ電場誘起相転移する前
に、光軸の方向が層法線からずれる現象である。前駆現
象が大きいと、バイアス電圧による光軸のずれが大きく
なり、コントラストが大きく低下する。However, in this antiferroelectric liquid crystal optical element, the contrast is very small, ie, 30, compared to 100 or more in an element obtained by combining a nematic liquid crystal and a TFT drive. This is due to light leakage due to the precursory phenomenon of the antiferroelectric liquid crystal in the dark state. The precursor phenomenon is a phenomenon in which the direction of the optical axis deviates from the layer normal before the electric field-induced phase transition from the antiferroelectric phase to the ferroelectric phase. If the precursor phenomenon is large, the deviation of the optical axis due to the bias voltage becomes large, and the contrast is greatly reduced.
【０００８】反強誘電性液晶を単純マトリクス方式で駆
動する場合、選択期間中は任意の透過率を得るため電圧
が印加されているが、非選択時にも表示色を維持するた
めバイアス電圧と、他の走査電極の画素に任意の透過率
を表示させるため信号電圧が印加されている。明状態や
中間調状態では、（バイアス電圧）＋（信号電圧）は、
シキイ値より小さくなるように設定されるので影響を受
けないが、暗状態では前駆現象のため大きな影響を受け
る。When the antiferroelectric liquid crystal is driven by a simple matrix system, a voltage is applied to obtain an arbitrary transmittance during a selection period, but a bias voltage is applied to maintain a display color even when the selection is not performed. A signal voltage is applied to display an arbitrary transmittance on the pixels of the other scanning electrodes. In the bright state and halftone state, (bias voltage) + (signal voltage)
Since it is set to be smaller than the threshold value, it is not affected, but in a dark state, it is greatly affected by a precursor phenomenon.
【０００９】反強誘電性液晶は、図５に示したようにバ
イアス電圧を印加しても透過率が０％であるのが理想で
あるが、現実は、反強誘電性液晶の前駆現象により、図
４に示したようにバイアス電圧を印加すると光漏れが生
じ透過率が数％になり、１００以上のコントラストを得
ることが困難になる。コントラストは（明状態での透過
率）／（暗状態での透過率）で求められるので、暗状態
での透過率の上昇はコントラストに大きく影響する。Ideally, the antiferroelectric liquid crystal has a transmittance of 0% even when a bias voltage is applied as shown in FIG. 5, but in reality, the antiferroelectric liquid crystal is caused by a precursory phenomenon of the antiferroelectric liquid crystal. When a bias voltage is applied as shown in FIG. 4, light leakage occurs and the transmittance becomes several percent, making it difficult to obtain a contrast of 100 or more. Since the contrast is calculated by (transmittance in the bright state) / (transmittance in the dark state), an increase in the transmittance in the dark state has a great effect on the contrast.
【００１０】上述したように、従来の反強誘電性液晶と
単純マトリクス駆動を組み合わせた液晶光学素子では、
表示色維持のためのバイアス電圧を印加する必要があ
り、反強誘電性液晶の前駆現象のため暗状態でもバイア
ス電圧により透過率が上昇し、１００以上のコントラス
トを得ることは困難である。As described above, in a conventional liquid crystal optical element combining an antiferroelectric liquid crystal and a simple matrix drive,
It is necessary to apply a bias voltage for maintaining a display color, and the transmittance increases due to the bias voltage even in a dark state due to a precursory phenomenon of antiferroelectric liquid crystal, and it is difficult to obtain a contrast of 100 or more.
【００１１】一方、特開平８−１２２８３０号公報（以
下、従来例１と呼ぶ。）には、反強誘電性液晶セルを２
枚重ね合わせ、暗状態での光漏れを防止し、コントラス
トを向上させた反強誘電性液晶素子が、開示されてい
る。この公報においては、２枚の液晶セルを反強誘電性
液晶の層法線を直交するように配置している。片方の液
晶セルは強誘電相のみを使用し、もう一方の液晶セルの
印加電圧を制御することにより暗状態から明状態および
中間調を表示する。反強誘電性液晶等の自発分極を有す
る液晶の光軸の傾く方向は、自発分極の符号と印加する
電圧の極性による。したがって、同じ液晶であれば印加
する電圧の極性を代えることにより、傾く方向が変わ
る。ここでは、正の電圧を印加したときに時計回りにθ
光軸が傾くとして、そのときθと表す。また、負の電圧
を印加したときに反時計回りにθ光軸が傾くとして、そ
のとき−θと表す。On the other hand, JP-A-8-122830 (hereinafter referred to as Conventional Example 1) discloses an antiferroelectric liquid crystal cell having two cells.
There is disclosed an antiferroelectric liquid crystal element in which sheets are superimposed, light leakage in a dark state is prevented, and contrast is improved. In this publication, two liquid crystal cells are arranged so that the layer normals of the antiferroelectric liquid crystal are perpendicular to each other. One of the liquid crystal cells uses only the ferroelectric phase, and displays a dark state to a bright state and halftone by controlling the applied voltage of the other liquid crystal cell. The tilt direction of the optical axis of a liquid crystal having spontaneous polarization such as an antiferroelectric liquid crystal depends on the sign of the spontaneous polarization and the polarity of the applied voltage. Therefore, in the case of the same liquid crystal, the tilt direction changes by changing the polarity of the applied voltage. Here, when a positive voltage is applied,
Assuming that the optical axis is inclined, it is represented by θ at that time. When a negative voltage is applied, the θ optical axis is inclined counterclockwise, and the angle is expressed as −θ.
【００１２】図６に示したように、強誘電相のみ使用す
る反強誘電性液晶セル１２をθｍａｘ光軸が傾いた強誘
電相にしたとき、もう一方の反強誘電性液晶セル１１に
転移するのに充分な電圧を印加し、θｍａｘ光軸が傾い
た強誘電相になったときは暗状態になり（ａ）、逆極性
の電圧を印加し−θｍａｘ光軸が傾いた強誘電相になっ
たときは、２θｍａｘが９０度でなければ明状態になり
（ｂ）、２θｍａｘが４５度のとき最も透過率が高い明
状態が得られる。この強誘電相のみ使用する反強誘電性
液晶セル１２の光軸をθｍａｘ傾けたときの、反強誘電
性液晶セル１１に印加する電圧による透過率の変化を、
図８の実線で示した。この方法では、バイアス電圧が印
加された暗状態を使用しないので、反強誘電性液晶の前
駆現象による光漏れは影響しなくなり、高コントラスト
の液晶光学素子が得られる。As shown in FIG. 6, when the antiferroelectric liquid crystal cell 12 using only the ferroelectric phase is changed to the ferroelectric phase in which the θmax optical axis is inclined, the transition to the other antiferroelectric liquid crystal cell 11 is made. When a voltage is applied to the ferroelectric phase in which the θmax optical axis is inclined, a dark state occurs (a), and a voltage of the opposite polarity is applied to the ferroelectric phase in which the -θmax optical axis is inclined. When 2θmax is not 90 degrees, a bright state is obtained (b), and when 2θmax is 45 degrees, a bright state with the highest transmittance is obtained. When the optical axis of the antiferroelectric liquid crystal cell 12 using only this ferroelectric phase is tilted by θmax, the change in transmittance due to the voltage applied to the antiferroelectric liquid crystal cell 11 is represented by
This is shown by the solid line in FIG. In this method, since a dark state to which a bias voltage is applied is not used, light leakage due to a precursory phenomenon of an antiferroelectric liquid crystal is not affected, and a high-contrast liquid crystal optical element can be obtained.
【００１３】図７に、強誘電相のみ使用する反強誘電性
液晶セル１２の光軸が−θｍａｘ傾いたときの、光軸の
配置と透過率の変化を示した。このときは、（ａ）のよ
うに反強誘電性液晶セル１１の光軸が−θｍａｘ傾いた
とき暗状態となり、（ｂ）のように反強誘電性液晶セル
１１の光軸がθｍａｘ傾いたとき、２θｍａｘが９０度
でなければ明状態になる。この強誘電相のみ使用する反
強誘電性液晶セル１２を−θｍａｘ光軸を傾けたとき、
反強誘電性液晶セル１１に印加する電圧による透過率の
変化を、図８の点線で示した。FIG. 7 shows the arrangement of the optical axis and the change in transmittance when the optical axis of the antiferroelectric liquid crystal cell 12 using only the ferroelectric phase is inclined by -θmax. At this time, when the optical axis of the antiferroelectric liquid crystal cell 11 is inclined by -θmax as shown in FIG. 2A, the dark state occurs, and as shown in FIG. 2B, the optical axis of the antiferroelectric liquid crystal cell 11 is inclined by θmax. At this time, if 2θmax is not 90 degrees, a bright state occurs. When the anti-ferroelectric liquid crystal cell 12 using only this ferroelectric phase is tilted with the -θmax optical axis,
The change in transmittance due to the voltage applied to the antiferroelectric liquid crystal cell 11 is shown by the dotted line in FIG.
【００１４】液晶光学素子は、液晶セルに電荷の直流成
分が蓄積されると信頼性が低下するので、ある期間ごと
に印加電圧の極性を代えることが好ましい。しかし、強
誘電相のみ使用する反強誘電性液晶セル１２は印加する
電圧の極性を交互に代えることができるので、電荷の蓄
積は避けられるが、もう一方の反強誘電性液晶セル１１
は、例えば図８に示したように透過率ａ％からｂ％への
変化のときは印加電圧の極性は交互に代わっているが、
透過率ａ％からｃ％への変化のときは印加電圧の極性は
代わらない。このように、表示するデータによっては、
同じ極性の電圧の印加が続き、電荷の蓄積により液晶光
学素子の動作信頼性が低下する。Since the reliability of the liquid crystal optical element decreases when the DC component of the electric charge is accumulated in the liquid crystal cell, it is preferable to change the polarity of the applied voltage every certain period. However, in the antiferroelectric liquid crystal cell 12 using only the ferroelectric phase, the polarity of the applied voltage can be alternately changed, so that charge accumulation can be avoided.
For example, as shown in FIG. 8, when the transmittance changes from a% to b%, the polarity of the applied voltage is alternately changed.
When the transmittance changes from a% to c%, the polarity of the applied voltage does not change. Thus, depending on the data to be displayed,
The application of a voltage of the same polarity continues, and the operation reliability of the liquid crystal optical element decreases due to the accumulation of charges.
【００１５】また、従来例１では同一走査ライン上に光
軸がθｍａｘ傾いた強誘電相と、光軸が−θｍａｘ傾い
た強誘電相が存在することもあるが、これを実現するに
は強誘電相に転移するのに充分な電圧と、逆極性の充分
な電圧を、同一走査ライン上に実現する必要がある。し
かし、これを単純マトリクス方式の駆動で実現するの
は、走査電極の電圧と信号電極の電圧の値、及び、非選
択時に透過率が保持できるバイアス電圧と信号電極の電
圧、反強誘電性液晶のシキイ値の値を選択しなければな
らず、非常に困難である。In the first conventional example, a ferroelectric phase whose optical axis is inclined by θmax and a ferroelectric phase whose optical axis is inclined by −θmax may exist on the same scanning line. It is necessary to realize a sufficient voltage for transition to the dielectric phase and a sufficient voltage of the opposite polarity on the same scan line. However, this can be realized by simple matrix driving because the voltage of the scanning electrode and the voltage of the signal electrode, the bias voltage and the voltage of the signal electrode that can maintain the transmittance when not selected, the antiferroelectric liquid crystal Is very difficult to choose.
【００１６】特開平１０−３９３２７号公報（以下、従
来例２と呼ぶ。）には、反強誘電性液晶セル、エレクト
ロクリニック効果を示すスメクティック液晶セルまたは
強誘電性液晶セルを２枚重ね合わせた液晶表示素子が開
示されている。この公報においては、２枚の液晶セルを
液晶セルの光軸を直交するように配置している。図９
は、従来例２の光軸の配置を示す模式図である。液晶セ
ル１１，２は反強誘電性液晶、もしくはエレクトロクリ
ニック効果を示すスメクティック液晶が充填されてい
る。（ａ）に示したように、液晶セル１１の光軸が−
θ、液晶セル１２の光軸がθ傾いたときは、明状態を示
す。同様に（ｃ）に示したように、液晶セル１１の光軸
がθ、液晶セル１２の光軸が−θ傾いたときは、明状態
を示す。一方、（ｂ）に示したように、液晶セル１１と
１２が電圧無印加状態のとき、もしくは（ｄ）と（ｅ）
に示したように、液晶セル１１と２の光軸の傾きがθも
しくは−θと同じ傾きのとき、暗状態を示す。Japanese Patent Application Laid-Open No. Hei 10-39327 (hereinafter referred to as Conventional Example 2) discloses an antiferroelectric liquid crystal cell, a smectic liquid crystal cell exhibiting an electroclinic effect or a ferroelectric liquid crystal cell. A liquid crystal display device is disclosed. In this publication, two liquid crystal cells are arranged so that the optical axes of the liquid crystal cells are orthogonal to each other. FIG.
FIG. 9 is a schematic diagram showing the arrangement of optical axes in Conventional Example 2. The liquid crystal cells 11 and 12 are filled with an antiferroelectric liquid crystal or a smectic liquid crystal exhibiting an electroclinic effect. As shown in (a), the optical axis of the liquid crystal cell 11 is −
When θ and the optical axis of the liquid crystal cell 12 are inclined by θ, a bright state is indicated. Similarly, as shown in (c), when the optical axis of the liquid crystal cell 11 is inclined by θ and the optical axis of the liquid crystal cell 12 is inclined by −θ, a bright state is indicated. On the other hand, as shown in (b), when the liquid crystal cells 11 and 12 are in a state where no voltage is applied, or (d) and (e)
As shown in (1), when the inclination of the optical axis of the liquid crystal cells 11 and 2 is the same as θ or −θ, a dark state is indicated.
【００１７】したがって、ある期間は液晶セル１１の光
軸の傾きを０から−θ、液晶セル１２の光軸の傾きを０
からθ利用し、次の期間では液晶セル１１の光軸の傾き
を０からθ、液晶セル１２の光軸の傾きを０から−θ利
用すれば、液晶セル１１と液晶セル１２は印加電圧の極
性を交互に代えることができる。しかし、暗状態は電圧
無印加状態を用いれば、反強誘電性液晶を単純マトリク
ス方式では、単層の反強誘電性液晶光学素子と同様にバ
イアス電圧による光漏れが生じる。一方、（ｄ）または
（ｅ）を使用すると、例えば、ある期間ごとに明、暗、
明と表示するとき、液晶セル１１または液晶セル１２の
いずれかで、連続して同じ極性の印加電圧が続くことに
なり、液晶光学素子の動作信頼性が低下する。Therefore, during a certain period, the inclination of the optical axis of the liquid crystal cell 11 is from 0 to -θ, and the inclination of the optical axis of the liquid crystal cell 12 is 0.
In the next period, if the inclination of the optical axis of the liquid crystal cell 11 is 0 to θ and the inclination of the optical axis of the liquid crystal cell 12 is 0 to −θ, the liquid crystal cell 11 and the liquid crystal cell 12 will have the applied voltage The polarity can be alternated. However, in the dark state, when no voltage is applied, light leakage due to a bias voltage occurs as in the case of a single-layer antiferroelectric liquid crystal optical element in a simple matrix type of antiferroelectric liquid crystal. On the other hand, when (d) or (e) is used, for example, light, dark,
When the display is bright, the applied voltage of the same polarity continues in either the liquid crystal cell 11 or the liquid crystal cell 12, and the operation reliability of the liquid crystal optical element is reduced.
【００１８】[0018]
【発明が解決しようとする課題】本発明は、上記従来の
課題を解決するもので、反強誘電性液晶光学素子の暗状
態の光漏れを防止し、高コントラストの反強誘電性液晶
光学素子を提供することが目的である。また、セルに印
加する電圧の極性を交互に代えることができる反強誘電
性液晶光学素子の駆動方法を提供することが目的であ
る。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is intended to prevent the leakage of light in the dark state of an antiferroelectric liquid crystal optical element and to provide a high contrast antiferroelectric liquid crystal optical element. The purpose is to provide. It is another object of the present invention to provide a method for driving an antiferroelectric liquid crystal optical element in which the polarity of a voltage applied to a cell can be alternately changed.
【００１９】[0019]
【課題を解決するための手段】上記目的を達成するため
に、本発明の反強誘電性液晶光学素子は、透明電極と配
向膜をそれぞれに有する一対の透明基板間に反強誘電性
液晶材料が狭持された反強誘電性液晶セルと、光軸が変
化する補償層とを偏光方向が直交するように配置した２
枚の偏光板の間に備えていることを特徴としている。In order to achieve the above object, an antiferroelectric liquid crystal optical element according to the present invention comprises an antiferroelectric liquid crystal material between a pair of transparent substrates each having a transparent electrode and an alignment film. And a compensating layer whose optical axis changes are arranged so that the polarization directions are orthogonal to each other.
It is characterized in that it is provided between two polarizing plates.
【００２０】本発明で使用する好適な補償層は、反強誘
電性液晶材料が狭持された反強誘電性液晶セル、強誘電
性液晶材料が狭持された強誘電性液晶セル、エレクトロ
クリニック効果を有するスメクティック液晶材料が狭持
されたエレクトロクリニック効果を有するスメクティッ
ク液晶セル、フェリ誘電性液晶材料が狭持されたフェリ
誘電性液晶セル、強誘電性高分子液晶材料が狭持された
強誘電性高分子液晶セル、強誘電性高分子液晶材料が狭
持された、フィルム状の強誘電性高分子液晶セル、及
び、ネマティック液晶材料が狭持された面内でスイッチ
ングするネマティック液晶セルのいずれかを使用する。The preferred compensating layer used in the present invention is an antiferroelectric liquid crystal cell holding an antiferroelectric liquid crystal material, a ferroelectric liquid crystal cell holding a ferroelectric liquid crystal material, an electroclinic. Smectic liquid crystal cell with electroclinic effect, ferrielectric liquid crystal cell with ferroelectric liquid crystal material sandwiched, ferroelectric with ferroelectric polymer liquid crystal material sandwiched Polymer liquid crystal cell, ferroelectric polymer liquid crystal cell sandwiched by ferroelectric polymer liquid crystal material, or nematic liquid crystal cell switching within the plane sandwiched by nematic liquid crystal material Or use.
【００２１】補償層は、単純マトリクス方式での駆動時
における、反強誘電性液晶セルの暗状態での光軸のずれ
θｏと直交する光軸と、逆極性の印加電圧における暗状
態の光軸のずれ−θｏと直交する光軸の２値を少なくと
も有する。また、反強誘電性液晶セルは、印加電圧の極
性に対する対称性を利用して、ある期間には０からθｍ
ａｘの光軸の変化、次の期間には０から−θｍａｘの変
化を利用する。The compensation layer has an optical axis orthogonal to the optical axis shift θo in the dark state of the antiferroelectric liquid crystal cell when driven in the simple matrix mode, and an optical axis in the dark state at an applied voltage of opposite polarity. At least two values of the optical axis orthogonal to the shift -θo. In addition, the antiferroelectric liquid crystal cell uses a symmetry with respect to the polarity of the applied voltage so that 0 to θm
The change of the optical axis of ax and the change of 0 to -θmax in the next period are used.
【００２２】反強誘電性液晶光学素子は単純マトリクス
方式の駆動では、暗状態でも、同一ラインの表示色維持
のためバイアス電圧が印加されている。したがって、反
強誘電性液晶セルは前駆現象により層法線から光軸が角
度θｏ傾く。一方、補償層の光軸が反強誘電性液晶セル
の光軸のずれθｏと、直交するように配置しているの
で、前駆現象による光漏れが防止でき、低い透過率の暗
状態が得られる。逆極性の暗状態のときは、補償層の光
軸を逆極性の印加電圧における暗状態の光軸のずれ−θ
ｏと直交するように切り替えることにより、前駆現象に
よる光漏れが防止でき、低い透過率の暗状態が得られ
る。また、反強誘電性液晶セルは、層法線を軸とする印
加電圧に対する光軸の傾きの対称性を利用して、ある期
間ごとに逆極性の電圧を印加できるので、電荷の蓄積は
避けられる。When the antiferroelectric liquid crystal optical element is driven by the simple matrix system, a bias voltage is applied to maintain the display color of the same line even in a dark state. Accordingly, in the antiferroelectric liquid crystal cell, the optical axis is inclined at an angle θo from the layer normal due to a precursory phenomenon. On the other hand, since the optical axis of the compensation layer is arranged so as to be orthogonal to the optical axis shift θo of the antiferroelectric liquid crystal cell, light leakage due to the precursor phenomenon can be prevented, and a dark state with low transmittance can be obtained. . In the dark state of the opposite polarity, the optical axis of the compensation layer is shifted by −θ from the optical axis of the dark state at an applied voltage of the opposite polarity.
By switching so as to be orthogonal to o, light leakage due to a precursor phenomenon can be prevented, and a dark state with low transmittance can be obtained. In addition, the antiferroelectric liquid crystal cell can apply a voltage of opposite polarity every certain period by utilizing the symmetry of the inclination of the optical axis with respect to the applied voltage with the layer normal as an axis. Can be
【００２３】よって、本発明に係る反強誘電性液晶光学
素子の駆動方法は、補償層の光軸が、反強誘電性液晶セ
ルのバイアス電圧印加による光学軸の傾き角θｏと逆極
性での傾き角−θｏに直交するように変化することを特
徴とし、補償層の光軸が、反強誘電性液晶セルのシキイ
値より高い電圧を印加した暗状態での傾き角θｄと逆極
性での傾き角−θｄに直交するように変化することを特
徴とし、又は、反強誘電性液晶セルの光学軸と、補償層
の光学軸を直交させることによって、暗状態を得ること
を特徴としている。Therefore, in the driving method of the antiferroelectric liquid crystal optical element according to the present invention, the optical axis of the compensation layer has a polarity opposite to the inclination angle θo of the optical axis due to the application of the bias voltage to the antiferroelectric liquid crystal cell. Characterized in that the optical axis of the compensation layer has a polarity opposite to that of the tilt angle θd in a dark state where a voltage higher than the threshold value of the antiferroelectric liquid crystal cell is applied. It is characterized in that it changes so as to be orthogonal to the tilt angle -θd, or that a dark state is obtained by making the optical axis of the antiferroelectric liquid crystal cell orthogonal to the optical axis of the compensation layer.
【００２４】[0024]
【発明の実施の形態】以下に、実施形態例を挙げ、添付
図面を参照して、本発明の実施の形態を具体的かつ詳細
に説明する。実施形態例１ 本実施形態例は、本発明に係る反強誘電性液晶光学素子
の実施形態の一例であって、図１は本実施形態例の液晶
光学素子の構成を示す断面図である。本実施形態例の反
強誘電性液晶光学素子（簡単に、液晶光学素子と言う）
は、図１に示すように、偏光方向が直交するように配置
した２枚の偏光板の間に、反強誘電性液晶セルと光軸の
傾き角を代えることができる補償層とを備える２層型の
反強誘電性液晶光学素子である。このとき、偏光板６の
偏光方向と反強誘電性液晶の層法線方向を一致させ、ま
た、偏光板７の偏光方向は偏光板６と直交するように配
置する。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment 1 This embodiment is an example of an embodiment of an antiferroelectric liquid crystal optical element according to the present invention, and FIG. 1 is a cross-sectional view showing a configuration of a liquid crystal optical element according to this embodiment. Antiferroelectric liquid crystal optical element of this embodiment (simply called liquid crystal optical element)
As shown in FIG. 1, a two-layer type comprising an antiferroelectric liquid crystal cell and a compensation layer capable of changing the inclination angle of the optical axis between two polarizing plates arranged so that the polarization directions are orthogonal to each other. Is an antiferroelectric liquid crystal optical element. At this time, the polarizing direction of the polarizing plate 6 is made to coincide with the layer normal direction of the antiferroelectric liquid crystal, and the polarizing direction of the polarizing plate 7 is arranged to be orthogonal to the polarizing plate 6.
【００２５】補償層９には反強誘電性液晶セルを使用
し、反強誘電性液晶セル８と補償層９としての反強誘電
性液晶セルは、互いの層法線が直交するように配置す
る。また、一対の透明基板１上に透明電極２を形成し、
透明電極２上に配向膜３を形成し（本図では両側の基板
上に形成しているが片側の基板のみでも素子の構成は可
能である）、透明電極２が対向するように配置して液晶
セルが構成される。この液晶セルの内部には反強誘電性
液晶材料が狭持される。An antiferroelectric liquid crystal cell is used for the compensating layer 9, and the antiferroelectric liquid crystal cell 8 and the antiferroelectric liquid crystal cell serving as the compensating layer 9 are arranged such that their layer normals are orthogonal to each other. I do. Further, a transparent electrode 2 is formed on a pair of transparent substrates 1,
An alignment film 3 is formed on the transparent electrode 2 (in this drawing, the alignment film is formed on both substrates, but an element can be configured with only one substrate). A liquid crystal cell is configured. An antiferroelectric liquid crystal material is held inside the liquid crystal cell.
【００２６】本実施形態例の液晶光学素子に用いる反強
誘電性液晶材料４は、前駆現象によるバイアス電圧印加
による光軸の回転が小さい方が明状態での透過率が大き
くなるので好ましい。また、補償層９としての反強誘電
性液晶セルに用いる液晶材料５は、反強誘電性液晶材料
４のバイアス電圧印加による光軸の層法線からのずれ角
θｏと、同じ大きさのメモリ角、もしくは、同じ大きさ
のバイアス電圧印加による光軸の層法線からのずれ角を
もつ材料を選択する。また、液晶材料４、５が同じ材料
であれば、バイアス電圧印加による光軸の層法線からの
ずれ角の温度依存性の影響による、光漏れがなくなるの
で好ましい。In the antiferroelectric liquid crystal material 4 used in the liquid crystal optical element of this embodiment, it is preferable that the rotation of the optical axis due to the application of the bias voltage due to the precursor phenomenon be small, because the transmittance in the bright state is increased. The liquid crystal material 5 used for the antiferroelectric liquid crystal cell as the compensation layer 9 has a memory having the same size as the deviation angle θo of the optical axis from the layer normal to the antiferroelectric liquid crystal material 4 due to the application of the bias voltage. A material having an angle or a deviation angle of the optical axis from the layer normal due to the application of a bias voltage of the same magnitude is selected. In addition, it is preferable that the liquid crystal materials 4 and 5 be the same because light leakage due to the temperature dependence of the shift angle of the optical axis from the layer normal due to the application of the bias voltage is eliminated.
【００２７】本実施形態例の液晶光学素子に用いられる
基板の材質は、ガラス、プラスチック、金属等である。
またカラーフィルターを有する基板を用いたり、顔料や
色素等を基板中に分散させることによって、カラー化す
ることができる。基板は電極が調光層側になるように設
置する。The material of the substrate used in the liquid crystal optical element of this embodiment is glass, plastic, metal, or the like.
Coloring can be achieved by using a substrate having a color filter, or by dispersing a pigment or a dye in the substrate. The substrate is placed so that the electrode is on the light control layer side.
【００２８】電極としてはインジウム−スズ−オキサイ
ド（ＩＴＯ）等の材質のものが利用できるが、ポリピロ
ール等の有機導電性薄膜も利用できる。また、使用する
基板自身が導電性を有している場合は、基板を電極とし
ても利用することもできる。電極は調光層と密着した状
態で設置する。これらの電極付き基板は液晶が配向する
ように処理されていることが望ましい。この際、２枚の
基板ともホモジニアス配向であることが望ましい。この
配向処理には、ＴＮ液晶、ＳＴＮ液晶等に用いられるポ
リイミド等の通常の配向膜が利用できる。ポリイミド等
の配向膜は、ポリイミド等が溶剤に溶け込んでいる可溶
性タイプでもよいし、焼成してポリイミド化する焼成タ
イプであっても構わない。またラビング等の配向処理を
行うことが望ましい。As the electrode, a material such as indium-tin-oxide (ITO) can be used, but an organic conductive thin film such as polypyrrole can also be used. If the substrate used has conductivity, the substrate can be used as an electrode. The electrodes are placed in close contact with the light control layer. It is desirable that these substrates with electrodes are treated so that the liquid crystal is aligned. At this time, it is desirable that both substrates have a homogeneous orientation. For this alignment treatment, a normal alignment film such as polyimide used for TN liquid crystal and STN liquid crystal can be used. The alignment film of polyimide or the like may be a soluble type in which polyimide or the like is dissolved in a solvent or a fired type in which the film is baked to form a polyimide. It is desirable to perform an alignment treatment such as rubbing.
【００２９】基板の間隔設定には、通常の液晶デバイス
に用いられるガラスまたは高分子樹脂から成るロッド
状、球状のスペーサーを使用することができ、その間隔
は１μｍ〜４μｍ程度が望ましい。反強誘電性液晶セル
８は単層での駆動と同様に、電場誘起相転移により強誘
電相からもう一方の強誘電相の光学軸の変化を利用す
る。明状態では強誘電相に相転移するのに充分な電圧を
印加し、暗状態ではバイアス電圧のみ印加する。中間調
表示の時は、その中間の電圧を印加する。一方、補償層
９の反強誘電性液晶セルは、反強誘電性液晶セル８の対
応する画素に印加されている電圧の極性に応じて、θｏ
と−θｏの光学軸を切り替えて使用する。For setting the distance between the substrates, a rod-shaped or spherical spacer made of glass or a polymer resin used for a normal liquid crystal device can be used, and the distance is desirably about 1 μm to 4 μm. The antiferroelectric liquid crystal cell 8 utilizes a change in the optical axis from one ferroelectric phase to another ferroelectric phase due to electric field-induced phase transition, as in the case of driving in a single layer. In a bright state, a voltage sufficient to cause a phase transition to a ferroelectric phase is applied, and in a dark state, only a bias voltage is applied. In the case of halftone display, an intermediate voltage is applied. On the other hand, the antiferroelectric liquid crystal cell of the compensation layer 9 has θo depending on the polarity of the voltage applied to the corresponding pixel of the antiferroelectric liquid crystal cell 8.
And -θo are switched for use.
【００３０】図２（ａ）に、暗状態での反強誘電性液晶
セル８と補償層９の反強誘電性液晶セルの光軸の配置を
示す。単純マトリクス方式の駆動では、暗状態でも、同
一ラインの表示色維持のためバイアス電圧が印加されて
いる。したがって、反強誘電性液晶セルは前駆現象によ
り層法線から光軸が角度θｏ回転する。一方、反強誘電
性液晶セルと層法線が直交するように配置した補償層の
反強誘電性液晶セルの光軸も同一方向に角度θｏで傾い
ており、前駆現象による光漏れが防止でき、低い透過率
の暗状態が得られる。FIG. 2A shows the arrangement of the optical axes of the antiferroelectric liquid crystal cell 8 and the antiferroelectric liquid crystal cell of the compensation layer 9 in a dark state. In the driving of the simple matrix system, a bias voltage is applied to maintain the display color of the same line even in a dark state. Therefore, in the antiferroelectric liquid crystal cell, the optical axis rotates by the angle θo from the layer normal due to the precursory phenomenon. On the other hand, the optical axis of the antiferroelectric liquid crystal cell of the compensation layer arranged so that the antiferroelectric liquid crystal cell and the layer normal are orthogonal to each other is also inclined at an angle θo in the same direction, so that light leakage due to a precursor phenomenon can be prevented. , A dark state with low transmittance is obtained.
【００３１】図２（ｂ）に明状態での反強誘電性液晶セ
ル８と補償層９の反強誘電性液晶セルの光軸の配置を示
す。反強誘電性液晶セルは強誘電相に電場誘起相転移さ
せるので光軸が角度θｍａｘ動く。一方、補償層９の反
強誘電性液晶セルの光軸は暗状態と同様に同一方向に角
度θｏ傾いている。このため、反強誘電性液晶セル単層
の液晶光学素子に比べ、同じ角度θｍａｘでの透過率が
小さくなる。このため、θｏが小さい材料を選択するの
が好ましい。しかし、明状態での透過率の低下よりも、
暗状態での透過率の低下がコントラストには大きく影響
するので、表示品質は向上する。FIG. 2B shows the arrangement of the optical axes of the antiferroelectric liquid crystal cell 8 and the compensation layer 9 in the bright state. Since the antiferroelectric liquid crystal cell causes an electric field-induced phase transition to the ferroelectric phase, the optical axis moves by an angle θmax. On the other hand, the optical axis of the antiferroelectric liquid crystal cell of the compensation layer 9 is inclined at the same angle θo in the same direction as in the dark state. Therefore, the transmittance at the same angle θmax is smaller than that of a liquid crystal optical element having a single layer of an antiferroelectric liquid crystal cell. Therefore, it is preferable to select a material having a small θo. However, rather than a decrease in transmittance in the bright state,
Since the decrease in the transmittance in the dark state greatly affects the contrast, the display quality is improved.
【００３２】図２（ｃ）に示したように、中間調状態で
も明状態と同様に、反強誘電性液晶セル８の光学軸の回
転方向と同方向に、補償層９の反強誘電性液晶セルの光
軸も角度θｏで傾いている。反強誘電性液晶セル８は、
電荷の蓄積を避けるため、ある期間ごとに逆極性の電圧
を印加する。補償層９の反強誘電性液晶セルの光軸の傾
き角は、反強誘電性液晶セルの対応する画素に同期させ
て、もう一方の傾き角に切り替える。As shown in FIG. 2C, the antiferroelectricity of the compensating layer 9 in the same direction as the rotation direction of the optical axis of the antiferroelectric liquid crystal cell 8 in the halftone state as in the bright state. The optical axis of the liquid crystal cell is also inclined at an angle θo. The antiferroelectric liquid crystal cell 8
In order to avoid charge accumulation, a voltage of opposite polarity is applied every certain period. The tilt angle of the optical axis of the antiferroelectric liquid crystal cell of the compensation layer 9 is switched to the other tilt angle in synchronization with the corresponding pixel of the antiferroelectric liquid crystal cell.
【００３３】図３に示したように、明状態、暗状態およ
び中間調状態での光軸の配置は、光軸の層法線からの回
転方向が逆になっただけで、同じである。従って、反強
誘電性液晶セル８、補償層９の反強誘電性液晶セルと
も、ある期間ごとに印加電圧の極性を交互に代えること
ができるので、電荷の蓄積は避けられ、高い動作信頼性
をもつ反強誘電性液晶光学素子がえられる。As shown in FIG. 3, the arrangement of the optical axes in the bright state, the dark state, and the halftone state is the same, except that the direction of rotation of the optical axis from the layer normal is reversed. Therefore, in both the antiferroelectric liquid crystal cell 8 and the antiferroelectric liquid crystal cell of the compensation layer 9, the polarity of the applied voltage can be alternately changed every certain period, so that charge accumulation can be avoided and high operation reliability can be obtained. Is obtained.
【００３４】また補償層９としては、強誘電性液晶セ
ル、エレクトロクリニック効果を有するスメクティック
液晶セル、フェリ誘電性液晶セル、強誘電性高分子液晶
セル、フィルム状の強誘電性高分子液晶セル、面内でス
イッチングするネマティック液晶セルを用いることもで
きる。このときも、本実施形態例の液晶光学素子に用い
た反強誘電性液晶セル８の前駆現象によるバイアス電圧
印加による光軸の層法線からのずれ角θｏと、同じ大き
さの光軸の傾きを持つ液晶材料を選択する。As the compensation layer 9, a ferroelectric liquid crystal cell, a smectic liquid crystal cell having an electroclinic effect, a ferrielectric liquid crystal cell, a ferroelectric polymer liquid crystal cell, a film-like ferroelectric polymer liquid crystal cell, Nematic liquid crystal cells that switch in-plane can also be used. Also at this time, the deviation angle θo of the optical axis from the layer normal due to the application of the bias voltage due to the precursory phenomenon of the antiferroelectric liquid crystal cell 8 used in the liquid crystal optical element of the present embodiment is equal to the optical axis of the same magnitude. Select a liquid crystal material with a tilt.
【００３５】実施形態例２ 本実施形態例は、実施形態例１と同じ構成であるが、反
強誘電性液晶セル８のシキイ値より低い暗状態を使用す
るのではなく、予めシキイ値より高い電圧を印加し、あ
る透過率で保持した状態を暗状態として使用する。この
とき、補償層９の光軸は、反強誘電性液晶セル８で暗状
態として保持した光軸θｄまたは−θｄと直交するよう
にする。また、そのような材料を選択する。 Embodiment 2 This embodiment has the same configuration as Embodiment 1, but does not use a dark state lower than the threshold value of the antiferroelectric liquid crystal cell 8 but preliminarily sets a threshold value higher than the threshold value. A state where a voltage is applied and a certain transmittance is maintained is used as a dark state. At this time, the optical axis of the compensation layer 9 is set to be orthogonal to the optical axis θd or −θd held in the dark state by the antiferroelectric liquid crystal cell 8. Also, select such a material.
【００３６】[0036]
【発明の効果】以上詳細に述べたように、本発明によれ
ば、偏光方向が直交するように配置した２枚の偏光板の
間に、透明電極と配向膜がそれぞれに形成された一対の
透明基板間に反強誘電性液晶材料が狭持された反強誘電
性液晶セルと、光軸の傾き角を代えることができる補償
層を配置することにより、高コントラストの反強誘電性
液晶光学素子を得ることができる。また、反強誘電性液
晶セルの暗状態での光軸のずれθｏと、補償層の光軸を
直交させることにより、暗状態を出現させ、逆極性のと
きも同様にして暗状態を出現させ、また、反強誘電性液
晶セルは、印加電圧の極性に対する透過率の対称性を利
用しているので、印加電圧の極性を交互に代えることが
できる。これにより、ある期間毎に逆極性の電圧を印加
できるので、高い動作信頼性が得られる。As described above in detail, according to the present invention, a pair of transparent substrates each having a transparent electrode and an alignment film formed between two polarizing plates arranged so that the polarization directions are orthogonal to each other. An antiferroelectric liquid crystal cell with an antiferroelectric liquid crystal material interposed between it and a compensating layer that can change the tilt angle of the optical axis is arranged to provide a high contrast antiferroelectric liquid crystal optical element. Obtainable. Also, by making the optical axis shift θo of the antiferroelectric liquid crystal cell in the dark state orthogonal to the optical axis of the compensation layer, a dark state appears, and a dark state appears in the same way when the polarity is reversed. Also, the antiferroelectric liquid crystal cell utilizes the symmetry of the transmittance with respect to the polarity of the applied voltage, so that the polarity of the applied voltage can be alternately changed. Thereby, a voltage of the opposite polarity can be applied every certain period, so that high operation reliability can be obtained.
【図１】実施形態例１の液晶光学素子の構成を示す断面
図である。FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal optical element according to a first embodiment.
【図２】実施形態例１の液晶光学素子の光軸の配置を示
す模式図である。FIG. 2 is a schematic diagram showing an arrangement of an optical axis of the liquid crystal optical element according to the first embodiment.
【図３】実施形態例１の液晶光学素子で、図２とは逆極
性の電圧を印加したときの光軸の配置を示す模式図であ
る。FIG. 3 is a schematic diagram showing the arrangement of optical axes when a voltage having a polarity opposite to that of FIG. 2 is applied to the liquid crystal optical element of the first embodiment.
【図４】反強誘電性液晶セルの印加電圧に対する光透過
率の変化を示すグラフである。FIG. 4 is a graph showing a change in light transmittance with respect to an applied voltage of an antiferroelectric liquid crystal cell.
【図５】反強誘電性液晶セルの理想的な印加電圧に対す
る光透過率の変化を示すグラフである。FIG. 5 is a graph showing a change in light transmittance of an antiferroelectric liquid crystal cell with respect to an ideal applied voltage.
【図６】従来の液晶光学素子の光軸の配置を示す模式図
である。FIG. 6 is a schematic diagram showing an arrangement of an optical axis of a conventional liquid crystal optical element.
【図７】従来の液晶光学素子で、図６とは逆極性の電圧
を印加したときの光軸の配置を示す模式図である。FIG. 7 is a schematic view showing the arrangement of optical axes when a voltage having a polarity opposite to that of FIG. 6 is applied to a conventional liquid crystal optical element.
【図８】従来の液晶光学素子の印加電圧に対する光透過
率の変化を示すグラフである。FIG. 8 is a graph showing a change in light transmittance with respect to an applied voltage of a conventional liquid crystal optical element.
【図９】従来の液晶光学素子の光軸の配置を示す模式図
である。FIG. 9 is a schematic diagram showing an arrangement of an optical axis of a conventional liquid crystal optical element.
１ 透明基板 ２ 透明電極 ３ 配向膜 ４ 反強誘電性液晶材料 ５ 液晶材料 ６、７ 偏光板 ８ 反強誘電性液晶セル ９ 補償層 １１ 反強誘電性液晶セル １２ 反強誘電性液晶セル DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Transparent electrode 3 Alignment film 4 Antiferroelectric liquid crystal material 5 Liquid crystal material 6, 7 Polarizer 8 Antiferroelectric liquid crystal cell 9 Compensation layer 11 Antiferroelectric liquid crystal cell 12 Antiferroelectric liquid crystal cell
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) G02F 1/141 G02F 1/13363 G02F 1/1347 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 7 , DB name) G02F 1/141 G02F 1/13363 G02F 1/1347
Claims (13)
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 強誘電性液晶材料が狭持された強誘電性液晶セルを補償
層として備えることを特徴とする反強誘電性液晶光学素
子。1. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. An anti-ferroelectric liquid crystal optical element comprising, as a compensation layer, a ferroelectric liquid crystal cell in which a ferroelectric liquid crystal material is sandwiched between two polarizing plates arranged so that directions are orthogonal to each other.
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 エレクトロクリニック効果を有するスメクティック液晶
材料が狭持されたエレクトロクリニック効果を有するス
メクティック液晶セルを補償層として備えることを特徴
とする反強誘電性液晶光学素子。2. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. An antiferroelectric device comprising, as a compensation layer, a smectic liquid crystal cell having an electroclinic effect in which a smectic liquid crystal material having an electroclinic effect is sandwiched between two polarizing plates arranged so that the directions are orthogonal to each other. Liquid crystal optical element.
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 フェリ誘電性液晶材料が狭持されたフェリ誘電性液晶セ
ルを補償層として備えることを特徴とする反強誘電性液
晶光学素子。3. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. An antiferroelectric liquid crystal optical element, comprising a ferrielectric liquid crystal cell in which a ferrielectric liquid crystal material is interposed between two polarizing plates arranged so that directions are orthogonal to each other, as a compensation layer.
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 強誘電性高分子液晶材料が狭持された強誘電性高分子液
晶セルを補償層として備えることを特徴とする反強誘電
性液晶光学素子。4. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. An antiferroelectric liquid crystal comprising a ferroelectric polymer liquid crystal cell in which a ferroelectric polymer liquid crystal material is sandwiched as a compensation layer, provided between two polarizing plates arranged so that the directions are orthogonal to each other. Optical element.
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 強誘電性高分子液晶材料が狭持されたフィルム状の強誘
電性高分子液晶セルを補償層として備えることを特徴と
する反強誘電性液晶光学素子。5. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. A ferroelectric polymer liquid crystal cell in which a ferroelectric polymer liquid crystal material is sandwiched is provided as a compensation layer between two polarizing plates arranged so that the directions are orthogonal to each other. Dielectric liquid crystal optical element.
一対の透明基板間に反強誘電性液晶材料が狭持された反
強誘電性液晶セルと、 光軸が変化する補償層とを偏光方向が直交するように配
置した２枚の偏光板の間に備え、 ネマティック液晶材料が狭持され、面内でスイッチング
するネマティック液晶セルを補償層として備えることを
特徴とする反強誘電性液晶光学素子。6. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal material is sandwiched between a pair of transparent substrates each having a transparent electrode and an alignment film, and a compensation layer whose optical axis changes. An anti-ferroelectric liquid crystal optical element, comprising a nematic liquid crystal cell sandwiched between two polarizing plates arranged so that the directions are orthogonal to each other, and having a nematic liquid crystal cell which switches in a plane as a compensation layer.
バイアス電圧印加による光学軸の傾き角θｏと逆極性で
の傾き角−θｏに直交するように変化することを特徴と
する請求項１から６のうちのいずれか１項に記載の反強
誘電性液晶光学素子。7. The optical axis of the compensating layer changes so as to be orthogonal to the tilt angle θo of the optical axis due to the application of the bias voltage of the antiferroelectric liquid crystal cell and the tilt angle −θo of the opposite polarity. The antiferroelectric liquid crystal optical element according to claim 1.
シキイ値より高い電圧を印加した暗状態での傾き角θｄ
と逆極性での傾き角−θｄに直交するように変化するこ
とを特徴とする請求項１から６のうちのいずれか１項に
記載の反強誘電性液晶光学素子。8. The optical axis of the compensation layer has a tilt angle θd in a dark state where a voltage higher than the threshold value of the antiferroelectric liquid crystal cell is applied.
The antiferroelectric liquid crystal optical element according to any one of claims 1 to 6, wherein the antiferroelectric liquid crystal optical element changes so as to be orthogonal to a tilt angle -θd having a polarity opposite to that of the liquid crystal.
の光学軸を直交させることによって、暗状態を得ること
を特徴とする請求項１から６のうちのいずれか１項に記
載の反強誘電性液晶光学素子。9. The dark state is obtained by making an optical axis of an antiferroelectric liquid crystal cell orthogonal to an optical axis of a compensation layer. Anti-ferroelectric liquid crystal optical element.
する電圧の極性を交換することを特徴とする請求項１か
ら６のうちのいずれか１項に記載の反強誘電性液晶光学
素子。10. The anti-ferroelectric liquid crystal optical element according to claim 1, wherein the polarity of the voltage applied to the anti-ferroelectric liquid crystal is changed every certain period. .
に記載の反強誘電性液晶光学素子の駆動方法であって、 補償層の光軸が、反強誘電性液晶セルのバイアス電圧印
加による光学軸の傾き角θｏと逆極性での傾き角−θｏ
に直交するように変化することを特徴とする反強誘電性
液晶光学素子の駆動方法。11. The method of driving an antiferroelectric liquid crystal optical element according to claim 1, wherein an optical axis of the compensation layer is a bias voltage of the antiferroelectric liquid crystal cell. -Θo with a polarity opposite to the tilt angle θo of the optical axis due to the applied voltage
A method for driving an antiferroelectric liquid crystal optical element, characterized in that it changes so as to be orthogonal to.
に記載の反強誘電性液晶光学素子の駆動方法であって、 補償層の光軸が、反強誘電性液晶セルのシキイ値より高
い電圧を印加した暗状態での傾き角θｄと逆極性での傾
き角−θｄに直交するように変化することを特徴とする
反強誘電性液晶光学素子の駆動方法。12. The method of driving an antiferroelectric liquid crystal optical element according to claim 1, wherein an optical axis of the compensation layer is a threshold value of an antiferroelectric liquid crystal cell. A method for driving an antiferroelectric liquid crystal optical element, wherein the tilt angle changes in a direction perpendicular to a tilt angle θd in a dark state to which a higher voltage is applied and a tilt angle −θd in a reverse polarity.
に記載の反強誘電性液晶光学素子の駆動方法であって、 反強誘電性液晶セルの光学軸と、補償層の光学軸を直交
させることによって、暗状態を得ることを特徴とする反
強誘電性液晶光学素子の駆動方法。13. The method of driving an antiferroelectric liquid crystal optical element according to claim 1, wherein an optical axis of the antiferroelectric liquid crystal cell and an optical axis of the compensation layer. A method for driving an antiferroelectric liquid crystal optical element, wherein a dark state is obtained by orthogonally intersecting.
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| JP25805498A JP3166726B2 (en) | 1998-09-11 | 1998-09-11 | Antiferroelectric liquid crystal optical element and driving method thereof |
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|---|---|---|---|
| JP25805498A JP3166726B2 (en) | 1998-09-11 | 1998-09-11 | Antiferroelectric liquid crystal optical element and driving method thereof |
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| JP3166726B2 true JP3166726B2 (en) | 2001-05-14 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6602806B1 (en) | 1999-08-17 | 2003-08-05 | Applied Materials, Inc. | Thermal CVD process for depositing a low dielectric constant carbon-doped silicon oxide film |
| US6635575B1 (en) | 1999-08-17 | 2003-10-21 | Applied Materials, Inc. | Methods and apparatus to enhance properties of Si-O-C low K films |
| KR102123006B1 (en) * | 2018-11-30 | 2020-06-15 | 한국생산기술연구원 | Led placement method of led mask |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100862076B1 (en) | 2002-12-24 | 2008-10-09 | 엘지디스플레이 주식회사 | Liquid Crystal Display Device Having Variable Viewing Angle |
| CN109031765A (en) * | 2018-09-06 | 2018-12-18 | 北京航空航天大学 | A kind of photoswitch based on the double-deck nematic liquid crystal |
-
1998
- 1998-09-11 JP JP25805498A patent/JP3166726B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6602806B1 (en) | 1999-08-17 | 2003-08-05 | Applied Materials, Inc. | Thermal CVD process for depositing a low dielectric constant carbon-doped silicon oxide film |
| US6635575B1 (en) | 1999-08-17 | 2003-10-21 | Applied Materials, Inc. | Methods and apparatus to enhance properties of Si-O-C low K films |
| KR102123006B1 (en) * | 2018-11-30 | 2020-06-15 | 한국생산기술연구원 | Led placement method of led mask |
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|---|---|
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