Browse Prior Art Database

Original Publication Date: 1977-Feb-28
Included in the Prior Art Database: 2004-Mar-29

Publishing Venue

Xerox Disclosure Journal


In an electrostatographic copier 10 in which imaging mater-ial is transferred from an image support surface 12 to an overlying copy sheet 26 in a transfer station 32 by elec-trical transfer charges, the variable leakage conduction of these transfer charges by the copy sheet away from the transfer area to contacting conductive sheet guide members 30, 42, etc., changes the available transfer field strength, thus affecting transfer efficiency and quality. Here the conductive members 30, 42 contacting the copy sheet 26 while it is in the transfer station are electrically con-nected to ground only through a high resistance 33, 35 whereby the transfer leakage currents through the paper provide a compensatory self-biasing floating voltage on the conductive guide surfaces which opposes these leakage currents. This voltage bias self-grounds through the re-sistor paths 33,35 when charged paper is not present. In the arrangement here 100 to 400 megohm resistances can suppress the leakage current, but much of the effect can be achieved by lower resistance values generating bias volt-