Patent ID: 6049686
Filing Date: 2000-04-11
Classification: G03G

Abstract:
A developer unit for developing a latent image recorded on an image receiving member with marking particles, to form a developed image, comprising:a donor member, spaced from the image receiving member for, transporting marking particles to a development zone adjacent the image receiving member;an electrode positioned in the development zone between the image receiving member and the donor member;a voltage supply for electrically biasing said electrode during a developing operation with an alternating and direct current voltage to detach marking particles from said donor member, forming a cloud of marking particles in the development zone, and developing the latent image with marking particles from the cloud;means for clearing toner from the donor member during non-developing operations;means for adjusting said alternating current voltage bias and said direct current voltage bias such the electrode polarity is electrically repulsive to any properly charged toner on the donor roll surface, when said clearing means is enabled, said adjusting means adjusts said alternating current voltage bias between 25V and 100V, and said direct current bias between 0V and 100V.