Charles M. Rankin

16.3: Development of a Flexible Electronic Display Using Photographic Technology

A bistable flexible electronic display has been developed based on photographic technology, processes, and materials. Using photographic film coating techniques, an aqueous cholesteric liquid crystal dispersion, a dielectric layer, and a dark layer were deposited onto patterned transparent conductors on a polymeric web. Second conductors were printed over the active display layers to complete display manufacture in a roll-to-roll process. Simple seven-segment displays and matrix displays have been generated using these techniques. The displays can use contact electronics to eliminate drive cost from the displays. Several prototype applications were demonstrated. Displays produced with these processes were low-cost, thin, flexible, passively driven, and retained an image without an applied electric field.

Single-substrate cholesteric liquid crystal displays by colloidal self-assembly

We report a single-substrate method for fabrication of reflective and bistable cholesteric liquid crystal displays on flexible substrates based on self-assembly of uniform droplets of liquid crystal in a polymer matrix to create a close-packed monolayer. The displays may be made on a large scale and exhibit switching voltages, brightness, and contrast approaching two-substrate methods such as the two-substrate polymerization-induced phase separation method.

6.1: Roll‐to‐Roll Manufacturing Considerations for Flexible, Cholesteric Liquid Crystal (ChLC) Display Media

Roll-to-roll methods and equipment to manufacture a bistable flexible electronic display have been developed. Displays produced with these processes are low-cost, thin, flexible, passively driven, and retain an image without an applied electric field. Using continuous coating techniques and equipment, an aqueous cholesteric liquid-crystal dispersion and a dark layer are deposited onto laser-etched patterned transparent conductors on a polymeric web. Second conductors are printed with a UV-curable polymer thick film ink over the active display layers, followed by slitting and chopping to complete the manufacture of display media in a full roll-to-roll process. Simple seven-segment and matrix displays can be generated using these techniques. This paper will focus on the manufacturing considerations for producing matrix display media.

Roll-to-roll manufacturing considerations for flexible, cholesteric liquid-crystal display (Ch-LCD) media

Abstract— Roll-to-roll methods and equipment to manufacture a bistable, passively driven display media on a flexible substrate have been developed. Using continuous coating techniques and equipment, cholesteric liquid-crystal droplets in a gelatin binder and a dark layer are simultaneously coated onto laser-etched-patterned transparent ITO conductors on a polymeric web. Second conductors are printed with a UV-curable polymer thick-film ink over the active display layers, followed by slitting and chopping to complete the manufacture of display media in a full roll-to-roll mode. Segmented- and matrix-display media can be generated using these techniques. This paper will focus on the manufacturing considerations for producing matrix-display media.

56.4: Cholesteric PDLC Displays with Low Driving Voltage

We present a new single-substrate approach for cholesteric polymer-dispersed liquid crystal (PDLC) displays that provides a uniform monolayer of liquid crystal domains over large areas. The monolayer structure, in combination with the most recent commercially available liquid crystal mixtures, enables the creation of flexible display devices with very low driving voltage.