| 摘要 |
PURPOSE:To display a large picture with high density which is thermally written at a high speed by writing the picture by transparent picture elements while using light scattering state as a background. CONSTITUTION:A liquid crystal substance 26 has a spontaneous spiral array because it contains liquid crystal having a cholesteric phase, and the dielectric constant is positive in case of an electric field having low frequency less than fc and negative in case of an electric field having high frequency more than fc because it contains dielectric constant dispersion type nematic liquid crystal. The main component is a smectic liquid crystal having positive dielectric constant anisotropy. If a high frequency is applied to the liquid crystal, a light scattering state takes place and the state is accumulated also after removing the electric field. The optical scattering state is not changed even if low frequency electric field less than 10<5>V/cm is applied, but if laser light is irradiated under the electric field and the liquid crystal is transferred up to liquid phase, the smectic phase after removing the laser light is turned to a transparent state. The written picture can be erased by applying a high frequency and partial erasing is also available. |
