A new toner display device using a conductive toner and charge transport layer has been developed. In this new toner display device, the toner movement is controlled by a switch of electric field polarity between two transparent electrodes. Two plates with the charge transport thin layer, CTL, are placed opposing each other, leaving a certain distance in between by using spacer. The charge transport materials are used as same as an organic photoreceptor in an electrophotography. The conductive toners on the CTL were charged by the hole injection from CTL to toner particles, and move to the front electrode. The toner particles are fixed on the front electrode due to the coulombic force between the toner and electrode across the CTL. The toner particles can be removed and moved toward to the back electrode by applying reverse electric field. The image can be recorded and erased easily by switching of electric field polarity.
Gugrae-Jo, Katsuhiko Sugawara, Katsuyoshi Hoshino, Takashi Kitamura, "New Toner Display Device Using Conductive Toner and Charge Transport Layer" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP15), 1999, pp 590 - 593, https://doi.org/10.2352/ISSN.2169-4451.1999.15.1.art00054_2