1316469 Electro-photography INTERNATIONAL BUSINESS MACHINES CORP 26 Oct 1970 [24 Nov 1969] 50721/70 Heading G2H [Also in Divison H1] A corona charging device for an earthed xerographic drum comprises charging wires 21 and auxiliary rod 30 electrodes alternately arranged in the same plane, the mountings for the charging and auxiliary electrodes being separable Fig. 2 (not shown). The charging and auxiliary electrodes may have diameters of 0.002 and 0.05 inch resp. The charging potential may be 6-8 kv. The auxiliary electrodes may have a potential of between earth potential and 25% of charging potential. A suppressor grid (42) Figs. 5 and 6 (not shown) may be situated between the charging/auxiliary electrodes and the drum.