GUEST-HOST LIGHT VALVE
Original Publication Date: 1985-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
An optically addressed liquid crystal light valve based on the guest-host effect is disclosed in the figure. Generally, in the absence of imaging light the electric field drops essentially across the photoconductor; however, when the photoconductor is imagewise exposed, the field drops imagewise across the liquid crystal film inducing optical changes which can be read-out with the aid of polarizers (twisted nematic effect). Between the photoconductor and the liquid crystal is in some cases an optical blocking layer to prevent the read-out light from interfering with the imaging light. In other cases, depending on the photoconductor, or the wavelength of read-out light used, a blocking layer is not required. See U.S. Patent No. 4,037,932.