ACTIVE BIAS ELECTRODES FOR REDUCING ELECTRIC FIELDS UNDERNEATH PRINT HEADS IN ELECTROSTATIC MEDIA TRANSPORT

摘要

PROBLEM TO BE SOLVED: To provide a system for reducing adverse effect on ink injection caused by electric fields on the surface of media.SOLUTION: A system includes: one or more print heads 12 for depositing ink onto a media substrate 14; a media transport 10 for moving the media substrate along a media path to pass the one or more print heads; a conductive platen 22 contacting a media transport belt 16; an electric field reducer that includes an alternating current charge device 20 positioned upstream of the one or more print heads; and one or more electrically isolated bias electrodes 26 in registration with ink deposition areas 24 of the one or more print heads. When media are on the media transport belt, the electric field reducer and electrodes reduce the electric field on the surface of the media, thereby reducing printing defects.