Intermittent DC bias charge roll with DC offset voltage

摘要

An apparatus and process for applying an electrical charge to a photoreceptor wherein a bias charge roll member is situated in contact or in close proximity with a surface of member to be charged such as a photoreceptor. The bias charge roll member is supplied with an electrical bias having a rectified AC waveform onto which a DC bias is superimposed after the waveform has been rectified. The result is the ability to raise the voltage potential of the photoreceptor with less pulse voltage and, more particularly, to increase the voltage potential of the photoreceptor along as if only DC voltage were applied far above what is possible in the prior art. Among the advantages of the invention is the ability to minimize photoreceptor wear at higher levels of photoreceptor charge since the DC-offset bias enables the second Paschen threshold to be avoided for higher levels of the photoreceptor charge.