PLZT ceramic numeric display devices

The longitudinal fringe-field electrooptic effect in slim-loop lead lanthanum zirconate titanate (PLZT) ceramics offers the best known possibility of using ferroelectric ceramics for low-voltage, high-contrast numeric and alphanumeric display devices. Such devices appear feasible using either transmitted or reflected ambient light. When using ceramics 75 μrn to 250 μm thick, ON-OFF contrast ratios exceeding 10 dB are obtained with electric fields of 8 kV/cm, and contrast ratios exceeding 20 dB are obtained at 16 kV/cm. These results imply that equally high contrast ratios may be achieved in very thin samples at comparable electric fields but at correspondingly lower applied voltages; e.g., 20-30 volts for a 10 dB contrast ratio with a 25 μm thick ceramic, and 40-60 volts for a 20 dB contrast ratio.