| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve uneven brightness caused by temperature dependence of inverted current and to realize a display with fast response and excellent gradation by specifying temperature dependence of sum of spontaneous polarization and a voltage lowering factor of a chiral smectic liquid crystal. SOLUTION: Influence of temperature fluctuation can be improved by constituting a liquid crystal element in such a way that temperature dependence of sum of spontaneous polarization Ps and voltage lowering factor Qt compensating the former is <=10% per 10 deg.C, optionally <=5% and desirably <=3%. As a method for introducing the voltage lowering factor Qt, for example, a method to use a composition in which an ionic additive is added to a chiral smectic liquid crystal can be mentioned. Optionally the ionic additive to be used is an organic ionic additive considering the affinity with the liquid crystal, and typically a surfactant can be mentioned. Also as in some case the liquid crystal compound itself tends to incorporate a property to exhibit the voltage lowering factor Qt, addition of this kind of liquid crystal compound to the chiral smectic liquid crystal may also be effective.</p> |
