Patent 7847254 was granted and assigned to NCR on December, 2010 by the United States Patent and Trademark Office.
A photoconductive device (2) comprises a plurality of photoconductive layers (6, 8, 10, 12), each photoconductive layer comprising photoconductive material (4) and a respective plurality of electrodes (16, 18), wherein the photoconductive layers (6, 8, 10, 12) are electrically connected together.