METHOD AND DEVICE FOR ADJUSTING TO A MINIMUM VALUE A TONER SUPPLY TO A DEVELOPING STATION OF AN ELECTROGRAPHIC PRINTING UNIT OR COPYING UNIT

摘要

The invention relates to electrographic printing units in which charge images of pictures that are to be printed are created upon an intermediate support and are inked with toner in a developing station. The supply of new toner into the developing station is controlled via a toner mark that is applied to the intermediate support. In order to prevent the support and toner from blending too long without new toner being added, a scenario that results in a deterioration of the printed image, the toner-conveying cycles are counted per unit of time. Should the number of toner-conveying cycles drop below a given value, a control mark that is greater than the toner mark is charged onto the intermediate support and inked in accordance with the measured toner concentration until the number of conveying cycles per unit of time once again exceeds said minimum value.