TFT-ADDRESSED CHOLESTERIC LIQUID-CRYSTAL PROJECTION DISPLAY

A TFT-addressing of Polymer-Stabilized Cholesteric Textures (PSCT) cel l has been accomplished with a novel mixture of polymer and liquid cry stal. To improve driving voltage and hysteresis width of the PSCT cell , we have investigated the effects of the molecular structure and morp hology of polymer matrix on the electro-optical properties. A Scanning Electron Microscopy (SEM) analysis showed that the polymer in the PSC T cell formed fibrillar aggregated beads with a sub-micron order diame ter. The distance between the neighboring fibrils directly affected th e electro-optical properties of the PSCT cell. By controlling the dist ance of the fibril with poly(4,4'-bis-acryloyloxy-diethylstilbene), PS CT cell demonstrates an excellent properties, i.e., driving voltage (V -10) of 7.1 V, a contrast ratio of 18, a hysteresis width of 0.4 V, an d a charge-holding ratio of 94%. An 8.9 inch color TFT-PSCT display pa nel was fabricated for overhead projection. The panel showed a light t ransmission 2.5 times as high as that of the ordinary TFT-TN (Twisted Nematic) display.