Electrostatic printing

Claim 1

THE METHOD OF PRODUCING A VISUAL REPRODUCTION OF A VISUAL OBJECT WHICH COMPRISES: PROVIDING A FIRST ASSEMBLY CONSTITUTING A LAYER OF ELECTRICALLY CONDUCTIVE MATERIAL AND A PHOTOCONDUCTIVE INSULATING LAYER OF MATERIAL HAVING A RESISTIVITY IN THE DARK OF AT LEAST 1012 OHM-CM. AND A RESISTIVITY WHEN EXPOSED TO LIGHT OF NOT MORE THAN 1010 OHM-C., DISPOSED THEREON AND SECURED THERETO AND A SEPARATE SECOND ASSEMBLY COMPRISING A LAYER OF ELECTRICALLY SEMICONDUCTIVE MATERIAL AND A SUPPORTING METAL LAYER SECURED THERETO AND LYING ALONG THE LAYER OF SEMICONDUCTIVE MATERIAL, THE RESISTANCE ACROSS SAID LAYER OF SEMICONDUCTIVE MATERIAL BEING BETWEEN ABOUT 107 AND 109 OHMS, SAID SEMICONDUCTIVE MATERIAL BEING SELECTED FROM MATERIALS WHICH ARE LESS INSULATING THAT THE MATERIAL OF THE PHOTOCONDUCTIVE INSULATING LAYER: DISPOSING SAID ASSEMBLIES IN INTIMATE RELATIONSHIP WITH THE SURFACE OF THE PHOTOCONDUCTIVE INSULATING LAYER OF THE FIRST ASSEMBLY IN PHYSICAL CONTACT WITH THE SURFACE OF THE ELECTRICALLY SEMICONDUCTIVE LAYER OF THE SECOND ASSEMBLY, APPLYING TO THE SUPPORTING METAL LAYER OF A D.C. ELECTRIC POTENTIAL WITH RESPECT TO THE LAYER OF ELECTRICALLY CONDUCTIVE MATERIAL WHEREBY CHARGE IS LEAKED FROM THE SOURCE OF POTENTIAL THROUGH THE AREA OF SAID PHYSICAL CONTACT TO THE PHOTOCONDUCTIVE INSULATING LAYER AND PROJECTING A LIGHT IMAGE OF SAID VISUAL OBJECT ONTO THE PHOTOCONDUCTIVE INSULATING LAYER THUS ESTABLISHING ON THE LAYER OF PHOTOCONDUCTIVE INSULATING MATERIAL AN ELECTROSTATIC REPRODUCTION OF SAID LIGHT IMAGE, SEPARATING THE PORTION OF THE FIRST ASSEMBLY BEARING THE ELECTROSTATIC REPRODUCTION OF THE OBJECT TO BE REPRODUCED FROM SAID SECOND ASSEMBLY AND APPLYING A DISPERSION OF CHARGED PARTICLES OF POWDERED MATERIAL TO THE SURFACE OF THE PHOTOCONDUCTIVE INSULATING MATERIAL BEARING THE ELECTROSTATIC REPRODUCTION OF THE IMAGE WITH THE RESULTANT FORMATION ON THE SAID SURFACE OF A POWDER DEPOSIT COMPRISING A VISUAL REPRODUCTION OF SAID LIGHT IMAGE.

Claim 2

THE METHOD OF PRODUCING A VISUAL REPRODUCTION OF A VISUAL OBJECT WHICH COMPRISES: PROVIDING A FIRST ASSEMBLY CONSTITUTING A LAYER OF ELECTRICALLY CONDUCTIVE MATERIAL AND A PHOTOCONDUCTIVE INSULATING LAYER OF MATERIAL HAVING A RESISTIVITY IN THE DARK OF AT LEAST 1012 OHM-CM. AND A RESISTIVITY WHEN EXPOSED TO LIGHT OF NOT MORE THAN 1010 OHM-C., DISPOSED THEREON AND SECURED THERETO AND A SEPARATE SECOND ASSEMBLY COMPRISING A LAYER OF ELECTRICALLY SEMICONDUCTIVE MATERIAL AND A SUPPORTING METAL LAYER SECURED THERETO AND LYING ALONG THE LAYER OF SEMICONDUCTIVE MATERIAL, THE RESISTANCE ACROSS SAID LAYER OF SEMICONDUCTIVE MATERIAL BEING BETWEEN ABOUT 107 AND 109 OHMS, SAID SEMICONDUCTIVE MATERIAL BEING SELECTED FROM MATERIALS WHICH ARE LESS INSULATING THAT THE MATERIAL OF THE PHOTOCONDUCTIVE INSULATING LAYER: DISPOSING SAID ASSEMBLIES IN INTIMATE RELATIONSHIP WITH THE SURFACE OF THE PHOTOCONDUCTIVE INSULATING LAYER OF THE FIRST ASSEMBLY IN PHYSICAL CONTACT WITH THE SURFACE OF THE ELECTRICALLY SEMICONDUCTIVE LAYER OF THE SECOND ASSEMBLY, APPLYING TO THE SUPPORTING METAL LAYER OF A D.C. ELECTRIC POTENTIAL WITH RESPECT TO THE LAYER OF ELECTRICALLY CONDUCTIVE MATERIAL WHEREBY CHARGE IS LEAKED FROM THE SOURCE OF POTENTIAL THROUGH THE AREA OF SAID PHYSICAL CONTACT TO THE PHOTOCONDUCTIVE INSULATING LAYER AND PROJECTING A LIGHT IMAGE OF SAID VISUAL OBJECT ONTO THE PHOTOCONDUCTIVE INSULATING LAYER THUS ESTABLISHING ON THE LAYER OF PHOTOCONDUCTIVE INSULATING MATERIAL AN ELECTROSTATIC REPRODUCTION OF SAID LIGHT IMAGE, SEPARATING THE PORTION OF THE FIRST ASSEMBLY BEARING THE ELECTROSTATIC REPRODUCTION OF THE OBJECT TO BE REPRODUCED FROM SAID SECOND ASSEMBLY AND APPLYING A DISPERSION OF CHARGED PARTICLES OF POWDERED MATERIAL TO THE SURFACE OF THE PHOTOCONDUCTIVE INSULATING MATERIAL BEARING THE ELECTROSTATIC REPRODUCTION OF THE IMAGE WITH THE RESULTANT FORMATION ON THE SAID SURFACE OF A POWDER DEPOSIT COMPRISING A VISUAL REPRODUCTION OF SAID LIGHT IMAGE.