APPLICATION OF PULSE BIAS ACROSS GAP BETWEEN DONOR AND IMAGED MEMBER

摘要

An apparatus for developing a latent xerographic image is disclosed. The development device comprises a toner supporting donor member adjacent, and in spaced relationship to, an image retaining member. Means are also provided to apply a pulsed electrical bias to the donor member to introduce an electrical field in the gap between the donor and image retaining member whereby the electroscopic particles are made more readily available to the charged image thereby resulting in fine image development. The pulse applied across the gap can be of two different frequencies to insure either good line copy quality or faithful tonal reproduction of an original. The instant donor development system enable reproduction of line and pictorial images.