摘要:
A chiral smectic liquid crystal composition is formed by including at least one species of a mesomorphic compound represented by the following formula (I): ##STR1## wherein X denotes F, Cl, Br, CF.sub.3, NO.sub.2 or CN; Y denotes a single bond, ##STR2## --CH.sub.2 O-- or --OCH.sub.2 --; and R denotes a linear or branched alkyl group having 1-20 carbon atoms optionally substituted. The composition shows improved switching characteristics and, when used in combination with an alignment film providing a high pre-tilt angle, provides an increased contrast at a large drive margin and with little tendency of monostabilization of a memory state.
摘要:
A liquid crystal device showing improved uniform alignment characteristic and switching characteristic is constituted by a pair of an upper substrate and a lower substrate, and a chiral smectic liquid crystal disposed between the upper and lower substrates. Each of the upper and lower substrates has thereon an electrode for applying a voltage to the liquid crystal and a uniaxial alignment film. The alignment films on the upper and lower substrates are provided with uniaxial alignment axes which cross each other so that the direction of crossing of the uniaxial alignment axes from the lower substrate to the upper substrate is identical to the direction of helical twist in cholesteric phase of the chiral smectic liquid crystal, and the chiral smectic liquid crystal is disposed in such an alignment state that the liquid crystal shows a pretilt angle .alpha., a cone angle H, an inclination angle .delta. of SmC.sup.* layer, and an apparent tilt angle .theta.a satisfying relationships of: H .theta.a>H/2. The crossing direction may preferably have a polarity (taken as "positive" in clockwise direction and "negative" in anticlockwise direction) which is the same as the polarity of the spontaneous polarization of the liquid crystal.
摘要翻译:显示出改善的均匀取向特性和切换特性的液晶装置由一对上基板和下基板以及设置在上基板和下基板之间的手性近晶液晶构成。 上基板和下基板都具有用于向液晶施加电压的电极和单轴取向膜。 上基板和下基板上的取向膜具有彼此交叉的单轴对准轴,使得单轴对准轴从下基板到上基板的交叉方向与胆甾醇相的螺旋扭转方向相同 手性近晶液晶和手性近晶液晶以这样的取向状态设置,使得液晶显示预倾角α,锥角+ E,crc / H /,SmC *层的倾斜角度δ,以及 满足以下关系的明显倾斜角θa:+ E,crc / H /α+δ和+ E,crc / H />θa> + E,crc / H / / 2。 交叉方向可以优选地具有与液晶的自发极化的极性相同的极性(顺时针方向为“正”,逆时针方向为“负”)。
摘要:
A liquid crystal device for gradational display, comprising: a pair of substrates each provided with an electrode, and a liquid crystal layer comprising a chiral smectic liquid crystal disposed between the substrates; the pair of substrates each having thereon alignment control layer provided with a uniaxial alignment axis, wherein aid liquid crystal layer comprises a striped region and a non-striped region where (1) the striped region and the non-striped region each assume a homogeneous alignment state, (2) the striped region extends in a direction perpendicular to the direction of the uniaxial alignment axis, and (3) each of liquid crystal molecules within the striped region and the non-striped region show bistability; and the liquid crystal molecules within the striped region have a threshold voltage, for switching between two stable states, different from that given by the liquid crystal molecules within the on-striped region. The above two regions (striped and non-striped region) having different threshold voltages each other are suitable as a display region for a liquid crystal device providing good gradation characteristic.
摘要:
A liquid crystal device with a decreased temperature-dependence of response speed is obtained by using a liquid crystal composition having a temperature range where the composition assumes chiral smectic C phase. The temperature range of chiral smectic C phase includes a) a first temperature range where the liquid crystal composition shows a cone angle in chiral smectic C phase which increases on temperature decrease down to a mediate temperature, and b) a second temperature range, below the first temperature range, where the liquid crystal composition shows a cone angle in chiral smectic C phase which decreases on further temperature decrease below the mediate temperature.
摘要:
A liquid crystal composition is composed of at least three types of mesomorphic compounds. The liquid crystal composition may preferably contain a mesomorphic compound having an indan skeleton represented by the formula (1) or (3) and a mesomorphic compound having a terminal cyclic group represented by the formula (2) or (4). The liquid crystal composition may also preferably further contain an optically active compound to be formulated as a chiral smectic (or ferroelectric) liquid crystal composition. When the chiral smectic liquid crystal composition is disposed between a pair of electrode substrates provided with uniaxial alignment axes, the liquid crystal composition may preferably be placed in an alignment state in C1 uniform alignment, so that a resultant liquid crystal device provides a higher contrast ratio and a wider drive voltage margin.
摘要:
A liquid crystal composition comprises at least three compounds represented by formulae (A), (B) and (C), respectively as in Claim 1. The compound of the formula (A) has an indan skeleton, the compound of the formula (B) has a quinoxaline skeleton, and the compound of the formula (C) has a pyrimidine skeleton or a benzothiazole skeleton and a terminal cyclic group comprising a cyclohexyl group or a phenyl group. The liquid crystal composition is effective in improving a display quality and drive characteristics of a liquid crystal device using the composition when the liquid crystal device is continuously driven for a long time.
摘要:
A liquid crystal composition contains a mesomorphic compound represented by the following formula (A): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.1 denotes a single bond, --O--, --CO--O-- or --O--CO--; X.sub.2 denotes a single bond, --OCH.sub.2 --, --CO--O-- or --O--CO--; n is an integer of 3-16; and A.sub.1, denotes ##STR2## and a mesomorphic compound represented by the following formula (B): ##STR3## wherein R.sub.2 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.3 and X.sub.4 independently denote a single bond, --O--, --CO--O-- or --O--CO--; m is an integer of 3-16; and A.sub.2 denotes ##STR4## The liquid crystal composition may preferably be formulated as a chiral smectic liquid crystal composition. The liquid crystal composition is useful in providing a liquid crystal device using the liquid crystal composition with a good alignment characteristic, a good drive characteristic, and a high contrast ratio.
摘要:
A liquid crystal composition contains a mesomorphic compound represented by the following formula (A): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.1 denotes a single bond, --O--, --CO--O-- or --O--CO--; X.sub.2 denotes a single bond, --OCH.sub.2 --, --CO--O-- or --O--CO--; n is an integer of 3-16; and A.sub.1 denotes ##STR2## and a mesomorphic compound represented by the following formula (B): ##STR3## wherein R.sub.2 denotes a linear or branched alkyl group having 1-18 carbon atoms; X.sub.3 and X.sub.4 independently denote a single bond, --O--, --CO--O-- or --O--CO--; m is an integer of 3-16; and A.sub.2 denotes ##STR4## The liquid crystal composition may preferably be formulated as a chiral smectic liquid crystal composition. The liquid crystal composition is useful in providing a liquid crystal device using the liquid crystal composition with a good alignment characteristic, a good drive characteristic, and a high contrast ratio.
摘要:
A liquid crystal device including: a pair of substrates and a chiral smectic liquid crystal disposed between the pair of substrates. Each of the pair of substrates has an electrode for applying a voltage to the liquid crystal. The pair of substrates is provided with respective uniaxial alignment axes extending in directions which are parallel to each other or intersect each other at a prescribed angle. The chiral smectic liquid crystal is placed in such an alignment state that the liquid crystal assumes at least two stable states and provides a pretilt angle .alpha. (degrees), a tilt angle H (degrees), an inclination angle .delta. (degrees) of the liquid crystal layer, and an apparent tilt angle .theta.a satisfying the following relationships (I) and (II) in a temperature range of 10.degree.-55.degree. C.:H .theta.a>H/2 (II).The liquid crystal provides a tilt angle H (degrees), an inclination angle .delta. (degrees) of the liquid crystal layer, and a spontaneous polarization Ps (nC/cm.sup.2) satisfying the following relationships (III) and (IV) at 55.degree. C.:H.times..delta.>70 (III), andH.times..delta./Ps>20 (IV).
摘要翻译:一种液晶装置,包括:一对基板和设置在所述一对基板之间的手性近晶液晶。 一对基板中的每一个具有用于向液晶施加电压的电极。 一对基板设置有相互平行的方向上延伸的相应的单轴对准轴线或以规定的角度彼此相交。 手性近晶液晶被置于液晶呈现至少两个稳定状态的对准状态,并提供预倾角α(度),倾角+ E,crc H + EE(度),倾斜角度 (度)和在10 -5℃的温度范围内满足以下关系式(I)和(II)的表观倾斜角θa:+ E,crc H +EEα+ δ和δ<α(I),+ E,crc H + EE> theta> + E,crc H + EE / 2(II)。 液晶提供倾斜角+ E,crc H + EE(度),液晶层的倾斜角度(度)和满足以下关系式(III)和(III)的自发极化Ps(nC / cm 2) IV)在55℃:+ E,crc H + EE×δ> 70(III)和+ E,crc H + EE×δ/ Ps> 20(IV)。
摘要:
A liquid crystal device is constituted by a pair of substrates each having thereon at least an electrode and an alignment control layer, and a liquid crystal composition disposed between the substrates. At least one of the alignment control layers has a thickness of at most 200 .ANG. or comprises polyimide. In the latter case, the pair of substrates have been subjected to mutually different aligning treatments. The liquid crystal composition comprises at least one species of a fluorine-containing mesomorphic compound in an amount of at least 70 wt. % comprising a fluorocarbon terminal portion and a hydrocarbon terminal portion, the terminal portions being connected with a central core, and having smectic mesophase or latent smectic mesophase, and comprises at least one species of a resistivity-modifying substance. The fluorine-containing mesomorphic compound comprises a compound having a fluorocarbon terminal portion containing at least one catenary ether oxygen atom in an amount of at least 30 wt. % based on the liquid crystal composition. The liquid crystal device is effective in improving switching characteristics, an alignment characteristic and display performances while retaining a bookshelf structure or a near bookshelf structure with respect to a smectic layer structure.