Reflective liquid crystal display and transmissive dye-doped liquid crystal display

摘要

An optical display employs a liquid crystal cell with a d&Dgr; n/. lambda. of approximately 0.2-0.8, allowing the cell's optical transmissivity to be modulated by an applied electric field through a dominant non-polarization rotation effect. For visible wavelengths, d. DELTA.n is approximately 0.1-0.4 microns, with a preferred value of about 0.25 microns. Applications include a reflective projection display in which input light is polarized at a greater than 0° and less than 90° angle, preferably about 20°, to the input LC directors of a twisted nematic cell; a reflective direct view system in which a quarter- wave plate is substituted for a polarization analyzer; and both a reflective and a transmissive guest-host system in which optical absorption by dye molecules is the dominant modulation mechanism.