The toner charge-to-mass ratio (Q/M) and toner mass per unit area (M/A) on both the developing roll and organic photoconductor (OPC) drum in a nonmagnetic mono component contact development system were studied by adjusting the dc bias. The bias between the developing roll and toner-adding roll from −200 to 200 V (Vdr−Vtar), and the bias between the developing roll and doctor blade from −400 to 600 V (Vdr−Vb) were the ranges of interest. The development potential between the developing roll and the OPC drum was kept at a constant value of 220 V. The developing roll, 2.0 cm in diameter, is made of soft polyurethane with a bulk electrical resistivity of 1010Ω-cm. The OPC drum used here has a diameter of 3.0 cm. The average Q/M ratio of toner on the developing roll is larger than that on the OPC drum corresponding to each Vdr−Vb when Vdr−Vtar is changing from 0 to 200 V. The Q/M ratios are affected by Vdr−Vb more on the OPC drum than on the developing roll. M/A ratios on both the developing roll and the OPC drum increased linearly as Vdr−Vtar was increased from −100 to 50 V and were nearly constant (changing within 0.2 mg/cm2) under a constant Vdr−Vb of 200, 400, and 600 V as Vdr−Vtar increased from 100 to 200 V.
Juei Tsang Hsu, Yu Hsiu Chang, Ker Ming Liu, "The Effects of Q/M and M/A on a Nonmagnetic Monocomponent Contact Development System under Different DC Bias Voltages" in Journal of Imaging Science and Technology, 1996, pp 364 - 368, https://doi.org/10.2352/J.ImagingSci.Technol.1996.40.4.art00016