Image contrast in toner display based on an electrical movement of black and white charged particles has been improved. Two types of black and white particles charged different electric polarity are enclosed between a two transparent electrodes. The black and white solid images are displayed by the switch of polarity of applied voltage in toner display cell. The image contrast ratio of reflectance of white to black solid image has been increased when the new type of white and black toner particles are used in toner display cell.
Takashi Kitamura, Nobuhiro Mizuno, Sakiko Nakamura, Katsuyoshi Hoshino, "Improvement of Image Contrast in Toner Display" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP20), 2004, pp 1005 - 1007, https://doi.org/10.2352/ISSN.2169-4451.2004.20.1.art00105_2