Method to eliminate cross coupling between blackness points at printers and a device to perform the method

Method to improve the printing quality of electrographic printers of the type, where an information carrier is brought into electric cooperation with at least one screen or grid shaped electrode matrix, which by control in accordance to desired configuration of the pattern at least partially opens and closes passages through the matrix by galvanic connection of this to at least one voltage source, and that by thus opened passages electric fields are exposed for attraction of pigment particles towards the information carrier, which is locateable between said electrode matrix and a background electrode,

• characterized therein, that the background electrode which comprises galvanically separated electrodes (8) as well as electrodes (5) in the electrode matrix individually can be given a voltage to a voltage level which is optimal for the process at every moment of time of the developing process.