NEGATIVE CORONA GENERATING DEVICE
Original Publication Date: 1990-Apr-30
Included in the Prior Art Database: 2004-Apr-05
Xerox Disclosure Journal
Certain difficulties have been observed in electrostatographic printing machines when using corona charging devices that produce a negative corona. It is believed that various nitrogen oxide species are produced by the corona and that these nitrogen oxide species are absorbed by solid surfaces. It is believed that these oxide species are adsorbed by the conductive shield which is typically aluminum as well as the housing of the corona generating device which is typically made from a structural plastic such as glass filled polycarbonate. It has been found that after such exposure when a machine is turned off for an extended period of time that the adsorbed nitrogen oxide species gradually are desorbed, that is the adsorption process is reversible. When operation of the machine is resumed a copy quality defect is observed in the prints produced in that a line image deletion or lower density image is formed across the width of the photoreceptor at that portion of its surface which was at rest opposite the corona generating device during the period of idleness. This difficulty may be avoided and/or controlled by coating those elements adjacent the corona generating device capable of adsorbing nitrogen oxide species with a substantially continuous thin conductive dry film of aluminum hydroxide containing from about 7 to 13 percent by weight graphite and about 3 to 10 percent by weight powdered nickel.