SYSTEM AND METHOD EMPLOYING PULSES TO REDUCE IMAGE ARTIFACTS
Original Publication Date: 1992-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
In ionographic devices such as those described in U.S. Patent No. 4,463,363 to Gundlach et al., an ion producing device generates ions to be directed to an imaging surface. Figure 1 illustrates the structure of an ionographic print head, 1010, including ion chamber 1012 and coronode 1014 supported within the chamber. Coronode controller 1200 supplies high voltage pulses, on the order of several thousand volts D.C., to coronode 1014. Reference potential source 1018, connected to the wall of chamber 1012, maintains head 1010 at voltage Vref. The corona discharge at coronode 1014 creates a source of ions (preferably positive) which are attracted to the chamber wall held at VH. Inlet channel 1020 delivers pressurized air into the chamber from a suitable source, 1022. Air flows out of ion chamber 1012 to the exterior of head 1010 through modulation channei 1024. As the air passes through chamber 1012, it carries ions into modulation channel 1024, past modulation bar 2028. Ions allowed to pass out of head 1010, through modulation channel 1024, are directed to charge receptor 1034. Subsequently, the ions come under the influence of conductive plate 1030 and a backing layer, which charge receptor dielectric surface 1031, where plate 1030 is slidingly connected via shoe 1032 to a voltage supply.