Powder feed for electrostatic printing system with an electric field free chamber

Claim 1

IN AN ELECTROSTATIC PRINTING SYSTEM OF THE TYPE WHEREIN THERE IS PROVIDED AN IMAGE ELECTRODE AND A BACK PLATE POSITIONED ADJACENT ONE SURFACE OF SAID IMAGE ELECTRODE FOR ESTABLISHING AN ELECTRIC FIELD THEREBETWEEN, AND ELECTROSCOPIC POWER PARTICLES ARE APPLIED TO THE OPPOSITE SURFACE OF SAID IMAGE ELECTRODE FOR PASSING THROUGH THE IMAGE APERTURES THERETHROUGH INTO SAID ELECTRIC FIELD, MEANS FOR APPLYING SAID POWDER PARTICLES TO SAID OPPOSITE SURFACE OF SAID IMAGE SCREEN COMPRISING CONDUCTIVE OPPOSITE DEFINING A POWER CLOUD CHAMBER, AN INPUT OPENING IN ONE WALL OF SAID POWDER CLOUD CHAMBER, AN OUTPUT OPENING IN A SECOND WALL OF SAID POWER CLOUD MEMBER OPPOSITE SAID ONE WALL, MEANS FOR APPLYING A POWDER CLOUD TO SAID INPUT OPENING OF SAID POWDER CLOUD CHAMBER TO TRAVERSE SAID POWDER CLOUD CHAMBER TO THE OUTPUT OPENING, AN OPENING IN A THIRD WALL OF SAID POWDER CLOUD CHAMBER WHICH IS ADJACENT TO SAID ONE AND SAID SECOND WALLS, A PLURALITY OF SPACED WIRE EXTENDING OVER SAID OPENING IN SAID THIRD WALL AND ELECTRICALLY CONNECTED TO SAID CHAMBER WALLS, MEANS FOR POSITIONING SAID POWDER CLOUD CHAMBER AND SAID SCREEN ADJACENT SAID OPPOSITE SURFACE OF SAID IMAGE SCREEN, AND MEANS FOR BIASING SAID PLURALITY OF SPACE WIRE RELATIVE TO SAID IMAGE SCREEEN FOR MOVING POWDER PARTICLES WHICH HAVE PASSED THROUGH SAID PLURALITY OF SPACED WIRES TOWARDS SAID OPPOSITE SURFACE OF SAID IMAGE SCREEN.