An incremental charging method was used to investigate one source of electrostatically induced image defects that produce image ghosting and image spread or blurring. Experimental evidence shows that charge carriers accumulate at the photoconductor surface with each image exposure and that a double charge layer forms at the CTL surface in the exposed (imaged) portion of the OPC drum. These charge carriers are liberated by reversing the surface potential polarity and migrate toward the substrate. The freed positive carriers are neutralized within the charge generation layer by electrons that are injected from the substrate. The incremental charging method attempts experimentally to quantify the charge carrier density in the subsurface layer and to determine the charge neutralization site upon reverse photoconductor charge.