Optically Rewritable Liquid Crystal Display

This chapter focuses on the progress in developing bistable Optically Rewritable Liquid Crystal Display (ORW LCDs) based on photoalignment technology over the past few years. It reviews photoalignment technology, which is essential for understanding ORW technology. The chapter presents the features of ORW LCDs including rewriting speed, gray levels and full-color generation, and flexible demonstration. It focuses on a typical photoalignment material, namely, sulfonic azo-dye SD1. The front polarizer is still the main disadvantage for ORW LCDs since it has to be removed for each erasing and rewriting, which is inconvenient or impractical in most applications. Flexible flat panel display technologies offer many potential advantages, such as very thin profiles, lightweight, the ability to flex, curve, conform, and fold, etc. Indium tin oxide electrodes are also unnecessary for ORW LCDs in the absence of applied voltage.