Xerographic copying apparatus

Claim 1

APPARATUS FOR DEVELOPING AN ELECTROSTATIC LATENT IMAGE COMPRISING A CONDUCTIVE CYLINDER HAVING A PHOTOCONDUCTIVE INSULATING LAYER ON ITS CURVED SURFACE AND ROTATABLY MOUNTED ON ITS LONGITUDINAL AXIS, DRIVE MEANS TO ROTATE SAID CYLINDER AND, SEQUENTIALLY MOUNTED AROUND THE PERIPHERY OF SAID CYLINDER IN THE DIRECTION OF ROTATION, A HIGH VOLTAGE CHARGING MEANS, AN OPTICAL EXPOSURE STATION, A DEVELOPING STATION, A TRANSFER STATION AND A CLEANING STATION, SAID DEVELOPING STATION COMPRISING A SUPPORT WEB POSITIONED WITH ONE SURFACE ADAPTED TO BE BROUGHT INTO FIRM CONTACT WITH THE CURVED CYLINDRICAL SURFACE, MEANS TO PRESS ONE PORTION OF SAID SUPPORT WEB INTO CONTACT WITH SAID CURVED CYLINDRICAL SURFACE, DRIVE MEANS ADAPTED TO MOVE SAID SUPPORT WEB NON-SYNCHRONOUSLY RELATIVE TO SAID CYLINDER BUT IN THE SAME DIRECTION AS THE DIRECTION OF PERIPHERAL MOVEMENT OF SAID CYLINDER AT THE POINT OF CONTACT BETWEEN SAID WEB AND SAID CYLINDER, SO THAT SAID WEB MOVES RELATIVE TO SAID CYLINDER AND MEANS REMOVED FROM THE CYLINDRICAL SURFACE FOR APPLYING TO THE WEB SURFACE A RELATIVELY UNIFORM COATING OF FINELY-DIVIDED POWDERED MATERIAL CHARGED TO AN ELECTROSTATIC POTENTIAL SUFFICIENT TO CAUSE ADHERENCE OF SAID POWDER TO THE WEB SURFACE AND TO CAUSE SELECTIVE ADHERENCE OF SAID POWDER TO SAID CYLINDRICAL SURFACE IN CONFORMITY WITH ELECTROSTATIC CHARGES THEREON.