CONTACT IONOGRAPHY HEAD
Original Publication Date: 1995-Oct-31
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
Present ionographic writing devices employ fields to drive ions from the print head to a receiver, as for example, in U. S. Patent 4,763,141. These air gap type systems require tight tolerances. An improved ionographic writing device 10 is shown in the Figure that eliminates the previously required tight tolerances between the head and receiver because it operates in contact with a receiver. Here, the first slit-forming set of electrodes 12 and 13 (nearest coronode ll), pumps ions to the lower potential electrode set 18 and 20. The two sets of electrodes are separated by insulators 15 and 16. Either or both of these lower electrodes can be segmented to provide individual addressable elements. Voltage differences applied across the lower slit elements may be used to control ion writing on receiver 30. Insulating layers 19 and 22 of, for example, Teflon, are attached to the lower electrodes and ride on insulating surface 32 of receiver 30. Insulating surface 32 can be made of anodized aluminum. The dielectric surface of the receiver will not charge exchange with the insulating layer of the lower electrode set. Arcing from the lower reference electrodes to the receiver is prevented if a voltage less than the minimum Paschen breakdown (340v) is used. A very thin air bearing could be used instead of actual contact.