Contrast improvement of transient nematic liquid crystal image bars by retardation compensation

The transient nematic liquid crystal image bar (TNLCIB) was developed for compact, low-cost printing applications. Switching of cells in the bar is through the electric-field-induced Frederiks transition. It uses a simple electronic driving circuit, requires only standard cell gap control technologies, and operates without temperature control devices over the range 20-80 degrees C. A description is given of how the contrast ratio of the device can be improved by the use of a compensator, and a simple analytic model for the compensated dark state is provided.<>