Development of an electrophoretic image display

The purpose of this work is to develop a 350 x 600 element X-Y addressed electrophoretic image display (EPID). Devices with improved Mylar layers have been fabricated using the photolithographic masks designed for the 512 character display. This improvement was achieved by using a new system and better pressing blocks. The photolithographic processes and ion-beam milling of the aluminum consistently have given good results. Ion-beam milling of the Mylar requires further development to ensure complete removal of material from the wells without destruction of the underlying electrode. Those areas of the completed devices which operated demonstrated good contrast at 2 lp/mm with the expected drive voltages. The display driver was redesigned to use a new high-voltage shift register for the row and column drivers, and a multiplexer was added to permit future access to any pixel, thereby eliminating the constraints imposed by a character generator. Construction of the driver has begun, and the printed circuit board for mounting the display has been ordered. The system for depositing In2O3/SnO2 (ITO) transparent grid electrodes is in operation. Transparent conducting ITO films have been deposited on glass and Mylar. Additional work is required to establish the deposition parameters necessary for reproducibly obtaining the desired properties of ITO on Mylar.