BICHARGEABLE ELECTROPHOTOGRAPHIC PAPER.

The photoconductor normally employed in making electrophotographic paper is zinc oxide, an n-type material. This means that it will accept negative but not positive charge. As a result, reversal prints normally require a different toner. There have been a variety of approaches to the solution of this problem. Zinc oxide photoconductive material has the binder is reported to effect a change in the photoconductive characteristics of zine oxide. Organic photoconductors have been used in place of zinc oxide. When doped, charging positively and negatively with equal facility becomes possible. Although a biochargeable photoconductor that fulfills both technical and practical developments has not yet been derived, advances in solid state physics suggest such a development in the near future.