We report a flexible bistable polymer dispersed smectic-A liquid crystal matrix display combining two advanced technologies developed by Kent State University and PolyDisplay ASA. The ion-doped smectic-A liquid crystal/polymer composite system produces lightweight, thin, and robust flexible displays with image memory, high contrast, wide viewing angle, and low power consumption.

We developed a composite system to produce robust bistable smectic-A ͑SmA͒ liquid crystal based flexible displays by encapsulating the liquid crystal material in a polymer wall structure. While keeping all the intrinsic bistable properties of the SmA material, the field-induced polymer walls bridge the two display substrates and bring significant advantages over the polymer dispersed liquid crystal structure. Here we analyze the performance of an encapsulated pixel and demonstrate superior electro-optical characteristics, high contrast ratio, and excellent sunlight readability.

The combination of two advanced technologies developed by Kent State University and TechnoDisplay ASA has resulted in the creation of high performance flexible bistable displays. While the bistable SmA (EASL DMD™) technology offers a more simplified display mode, long term stability, and an excellent contrast, the PDLC technology provides simplicity of manufacturing while maintaining the standard characteristics and strength of the display. Along with their lighter weight, the flexible display prototypes demonstrate high contrast ratio, excellent viewing angle characteristics, low power consumption, and a long lifetime.

The bistability, wide viewing angle, paper-like sunlight readability and outstanding transmission of displays based on the effect of electrically reversible memory in SmA LC fulfills the needs of certain application areas and opens new application possibilities. This paper focuses on the performance, manufacturing aspects and the current areas of SmA displays development. The simplicity of the display and its manufacturing has enabled PolyDisplay ASA to start commercialization of EASL DMD TM products based on SmA LC within a number of market segments.

Bistable electrically addressed smectic A liquid crystal (LC) cells with 6.5" diagonals have been prepared in monochrome and color. A process for converting the focal conic LC microstructure of filled cells into the homeotropic (transparent) texture is discussed. When driven to an opaque state, the LC scatters light, predominantly in a forward direction. This scattering of light allows for preparation of display modules with large viewing angles and excellent sunlight readability.