摘要:
A liquid crystal (composition) containing a ferroelectric liquid crystal shows a layer inclination angle .delta. in smectic phase providing a specific temperature dependence. The inclination angle .delta. increases on temperature decrease down to a mediate temperature and decreases on temperature decrease below the mediate temperature. The inclination angle .delta. keeps a positive value in an ambient temperature or starts to increase again on further temperature decrease before it reaches zero degrees. The liquid crystal (composition) is usable for providing a liquid crystal device or apparatus with decreased temperature dependences of driving conditions and improved low-temperature storage properties.
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 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.
摘要:
A liquid crystal device having a pair of electrode substrates, and a liquid crystal composition disposed between the substrates. At least one of the substrates is provided with an alignment control layer having a thickness of at most 200 Å and having been subjected to a rubbing uniaxial aligning treatment. The liquid crystal composition contains at least 30 wt. % of (i) at least one species of a fluorine-containing mesomorphic compound (B) represented by a formula (II) having smectic C phase and providing a tilt angle below 30 degrees at a temperature 15° C. below an upper limit temperature of said smectic C phase (ii) at least one species of compound (C) in an amount at least 5 wt. % represented by the formula (II) having a smectic C phase and which provides a tilt angle of at least 30 degrees at a temperature 15° C. below an upper limit temperature of said smectic C phase.
摘要:
A liquid crystal device is constituted by a pair of oppositely disposed substrates including a first substrate provided with a first alignment control layer which has been subjected to a uniaxial aligning treatment and a second substrate provided with a second alignment control layer which has not been subjected to a uniaxial aligning treatment, a sealing member disposed so as to seal up a peripheral portion of the first and second substrates to form a spacing therebetween, and a dispersion member (e.g., spacer beads or adhesive particles) and a liquid crystal disposed in the spacing while contacting the first and second aligning control layers. The dispersion member has been subjected to a surface treatment with a material constituting the second alignment control layer. The surface-treated dispersion member is effective in suppressing an occurrence of a reverse domain within a display region of the liquid crystal device, thus preventing flickering and improving a contrast.
摘要:
A liquid crystal device is constituted by a pair of substrates each having thereon an electrode for voltage application, a chiral smectic liquid crystal composition disposed between the substrates so as to assume at least two optically stable states. At least one of the substrates is provided with an alignment control layer having a thickness of at most 200 .ANG. or comprising polyimide. The substrates have been subjected to different aligning treatments at their opposite faces each contacting the composition. The composition comprises at least three fluorine-containing mesomorphic compounds each comprising a fluorocarbon terminal portion and a hydrocarbon terminal portion, the terminal portions being connected with a central core, the compounds having smectic mesophase or latent smectic mesophase; said at least three mesomorphic compounds comprising a compound having a fluorocarbon terminal portion containing one catenary ether oxygen atom, a compound having a fluorocarbon terminal portion containing two catenary ether oxygen atoms, and a compound having a fluorocarbon terminal portion containing three catenary ether oxygen atoms. The above liquid crystal device is effective in improving a duration margin to provide good drive characteristic when driven.
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, comprising: at least one optically active mesomorphic compound having an asymmetric carbon atom to which a fluorine atom is directly bonded.
摘要:
A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 and R.sub.2 respectively denote a linear or branched alkyl group having 1-8 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, ##STR2## Y.sub.1 denotes --CH.sub.2 O-- or --OCH.sub.2 --; and m and n are respectively 1 or 2; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, R.sub.4 denotes a linear alkyl group having 1-10 carbon atoms; X.sub.3 denotes a single bond, ##STR4## Y.sub.2 denotes ##STR5##
摘要:
A ferroelectric chiral smectic liquid crystal composition, comprising at least one optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.1 denotes a single bond, ##STR2## and at least one optically active compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-14 carbon atoms; R.sub.4 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.2 denotes a single bond, ##STR4##