METHOD FOR MAINTAINING FERROELECTRIC LIQUID CRYSTAL IN TRANSPARENT STATE

摘要

PURPOSE:To make a ferroelectric liquid crystal transparent and to improve the transmittance of light by impressing repeatedly a pulse voltage between electrodes sandwiching the liquid crystal. CONSTITUTION:The ferroelectric liquid crystal is a chiral smectic phase and is made into the helical structure in which the direction of the molecular long axis swings and rotates by each layer while maintaining the certain specified angle theta of inclination relative to the perpendicular to the smectic layer shown in figure (a). The state of figure (a) transfers to the state of figure (b) and all the directions of the dipole moments are unified to create the transparent state when the voltage is impressed thereto in such a state. The electric power loss occurring in ionic current increases when the DC is kept impressed and therefore the electric loss is decreased by increasing first the crest value or impression time of the impulsive voltage but decreasing gradually the pulse height or widening the pulse interval. The power loss is thus decreased and the transparent state is maintained while the deterioration of the liquid crystal is prevented.