Matrix addressed electrophoretic displays

Electrophoretic image displays (EPID) exhibit excellent optical characteristics, good response times, and low power consumption. However, there is no readily accessible voltage threshold in the optical response for an EPID device, and hence standard x-y addressing techniques are not applicable. This paper will describe a practical and reliable technique for providing such a threshold based upon the use of a control electrode. The control electrode design permits x-y addressing at I.C. compatible voltages, line at a time addressing rates of approximately 5 msec per line and high resolution (5 lines/mm). The design and fabrication of prototype 7×9 matrix alphanumeric devices will be described and preliminary performance characteristics will be presented.