Abstract: Charged particles suspended in a medium such as Fluorinert™ Electronic Liquid are used to electrophoretically control total internal reflection (TIR) at a retro-reflective surface formed on a high refractive index material. Prismatic structures redirect ambient light from an overhead light source toward a display image and then from the image to the region in front of the image, yielding a high contrast reflective display. A transparent planar waveguide front lights the display with sequential flashes of red, blue and green light to generate a full color display. TIR can also be controlled at retro-reflective surfaces by means of a vapor-liquid phase transition, or by changing the absorption coefficient of a material using electrical, chemical and/or electrochemical methods.

Abstract: A display device and method in which electrophoresis and/or dual prismatic surfaces are used to controllably frustrate total internal reflection at an interface between materials having different refractive indices. In one embodiment, an array of solid dielectric light fibers is surrounded by an electrophoretic medium such as acetonitrile. In the absence of electrophoretic activity, the fibers totally internally reflect light which passes into the fibers, and a reflector returns the light for diffuse emission through the fibers ends. If the fibers are subjected to electrophoretic activity their TIR capability is frustrated. A second embodiment redirects light through two prismatic surfaces in a manner which permits the TIR phenomenon to occur and to be controlled at a flat surface. A third embodiment uses both electrophoresis and dual prismatic surfaces to achieve gapless control of the TIR phenomenon at a flat surface.