Electrostatic printing wherein screen carries powder between loading and printing points

Claim 1

IN AN ELECTROSTATIC PRINTING SYSTEM, A CONDUCTIVE APERTURED SCREEN HAVING A PRINTING SIDE AND A BACK SIDE WHICH IS OPPOSITE SAID PRINTING SURFACE, A MASKING MATERIAL BLOCKING A PORTION OF THE SCREEN APERTURES TO LEAVE THE REMAINING UNBLOCKED APERTURE ARRANGED IN THE FORM OF A DESIRED IMAGE, SAID MASKING MATERIAL EXTENDING BEYOND SAID PRINTING SIDE OF SAID SCREEN, MEANS ESTABLISHING A SCREEN LOADING LOCATION, MEANS ESTABLISHING A SCREEN UNTION, MEANS FOR RELATIVELY MOVING SAID SCREEN BETWEEN SAID SCREEN LOADING LOCATION AND SAID SCREEN UNLOADING LOCATION, SAID MEANS ESTABLISHING A SCREEN LOADING LOCATION INCLUDING A SOURCE OF ELECTROSCOPIC POWDER PARTICLES, EACH OF SAID POWDER PARTICLES BEING SMALLER THAN THE APERTURES OF SAID SCREEN, MEANS FOR TRANSFERRING POWDER FROM SAID SOURCE ONTO SAID PRINTING SIDE OF SAID SCREEN, CLEANING WIPER BLADE MEANS POSITIONED BETWEEN SAID SCREEN LOADING AND UNLOADING POSITION FOR REMOVING POWDER PARTICLES DEPOSITED OVER SAID SCREEN MASKING MATERIAL AT SAID SCREEN LOADING LOCATION, SAID MEANS ESTABLISHING SAID SCREEN UNLOADING LOCATION INCLUDING MEANS FOR ESTABLISHING AN ELECTRIC FIELD BETWEEN SAID SCREEN AND AN IMAGE RECEIVING OBJECT POSITIONED ADJACENT SAID PRINTING SIDE OF SAID SCREEN, AND PRINTING WIPER MEANS IN CONTACT WITH THE BACK SIDE OF SAID SCREEN, SAID PRINTING WIPER MEANS MECHANICALLY AGITATING AND WIPING THE BACK SIDE OF SAID SCREEN FOR MECHANICALLY DISLODGING THE POWDER PARTICLES ON SAID SCREEN INTO THE ELECTRIC FIELD BETWEEN SAID SCREEN AND AN IMAGE RECEIVING OBJECT TO BE MOVED TOWARD SAID IMAGE RECEIVING OBJECT UNDER THE INFLUENCE OF SAID ELECTRIC FIELD.