JPS6433521A - Liquid crystal optical modulator - Google Patents

Abstract

PURPOSE:To obtain a steep threshold characteristic by using a memory type liquid crystal for a liquid crystal and generating or annihilating fine orientation regions of the directors different from each other between transparent conductive films, thereby executing optical modulation. CONSTITUTION:Driving of a cell is executed by impressing a positive voltage thereto in such a manner that the electric field exceeding the threshold is generated in both of stripped electrodes 4 and a 1st common electrode 5 if the 2nd common electrode 1 is assumed to be ground potential. As a result, the directors of the liquid crystal molecules are arrayed and this state is determined as the 1st state. Only the stripped electrodes 4 face upward and the oriented state having the molecule directors 23 is obtd. if both the electrodes 1 and 5 are grounded and the negative voltage exceeding the threshold is impressed only to the striped electrodes 4. This state is determined as the 2nd state. The 1st state is the state in which the orientation of the liquid crystal molecules is homogeneous and the transparent state in which incident light transmits through the liquid crystal as it is. On the other hand, the 2nd state is the state in which the incident light diffracts and scatters. The full surface erasing is, therefore, executed by using the 1st state and writing is executed in the 2nd state.