Light-Activated Liquid Crystal Light Valve for Projection Displays
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
It is well known that the liquid crystal used in the first-generation of light-activated light valves (LALV) was operated in the dynamic scattering (DS) mode. The second generation of these devices used the hybrid field effect of the liquid crystal (LC) (electric field- controlled birefringence (ECB)). The power consumption of the dynamic scattering of LC is relatively high (mW/cm2) as compared to the ECB mode of operation (mW/cm2). One of the advantages of ECB LALV is that it can be used for color displays by modulating the intensity of the input light and using a single cell only. It requires three cells for color displays using DS LALVs. In addition, the resistivity of the LC in the ECB LALV is high so that the rate of the charge leakage through the LC cell is small, resulting in better sensitivity and contrast.