Browse Prior Art Database

Original Publication Date: 1978-Oct-31
Included in the Prior Art Database: 2004-Mar-31

Publishing Venue

Xerox Disclosure Journal


• An electrophoretic display system is disclosed which utilizes • two immiscible phases. One phase is made of a finely divided pigment of high light scattering material, e.g., white rutile type TiO., pigment dispersed in a medium such as tricresyl • phosphatdt The second phase is a colored dye solution, e.g., a clear dark red solution formed by dissolving Amaplast Black BY in dodecane. The two phases, i.e., the pigment treated with tricresyl phosphate and the dye solution, are mixed to-gether and placed between transparent conductive electrodes. Upon application of electric field across the cell, the TiO pigment will migrate to one of the electrodes making tha electrode appear white. The appearance of the opposite electrode is black due to the combined effect on light of the highly light scattering Ti0-, and the absorption by the red dye solution of the light reflebted by the Ti02. A high contrast black and white image can thus be readily formed by using an imagewise electrical field. The system can be cycled for a relatively long period of time because the treatment for the pigment keeps the pigment from adsorbing the dye preserving the high contrast of the system.