Method for creating multiple electrostatic copies by persistent conductivity

Claim 1

AN ELECTROPHOTOGRAPHIC PROCESS FOR MAKING MULTIPLE COPIES FROM A SINGLE, REPETITIVELY REJUVENATED ELECTROSTATIC LATENT IMAGE RESIDING ON THE SURFACE OF AN ELECTROPHOTOGRAPHIC PLATE COMPRISING A PHOTOCONDUCTIVE INSULATING LAYER COATED ON A CONDUCTIVE SUBSTRATE, WHEREIN SAID LAYER EXHIBITS PERSISTENT CONDUCTIVITY SAID PROCESS COMPRISING THE STEPS OF: A. UNIFORMLY ELECTROSTATICALLY CHARGING THE EXPOSED SURFACE OF SAID LAYER IN THE ABSENCE OF ACTIVATING RADIATION TO A VOLTAGE OF A FIRST POLARITY TO CONDITION SAID LAYER BY RENDERING SAID LAYER UNIFORMLY NON-CONDUCTIVE, THEREBY CONVERTING ANY PRE-EXISTING CONDITION OF PERSISTENT CONDUCTIVITY IN NON-IMAGES AREAS TO A CONDITION OF NON-CONDUCTIVITY AND ALSO CONVERTING ANY PRE-EXISTING IMAGE PATTERN FROM ITS GIVEN POLARITY TO A CONDITION OF BEING INDISTINGUISHABLE FROM SAID PRE-EXISTING NON-IMAGE AREAS, B. UNIFORMLY ELECTROSTATICALLY CHARGING THE EXPOSED SURFACE OF SAID LAYER TO A VOLTAGE OF A SECOND BUT OPPOSITE POLARITY TO SENSITIZE SAID LAYER, SAID OPPOSITE POLARITY VOLTAGE BEING GREATER THAN ZERO AND APPROACHING THE CHARGE ACCEPTANCE POTENTIAL OF SAID LAYER, C. SUBJECTING SAID EXPOSED LAYER SURFACE TO AN ACTIVATING RADIATION IN IMAGEWISE CONFIGURATION CORRESPONDING AN IMAGE TO BE REPRODUCED TO REATE A VARYING PRESISTENT CONDUCTIVITY NON-IMAGE AREA IN CONTRAST TO SAID IMAGEWISE CONFIGURATION IN SAID LAYER, SAID PERSISTENT CONDUCTIVITY NON-IMAGE AREA OPERATING TO SELECTIVELY DISCHARGE SAID EXPOSED LAYER SURFACE AND THEREBY RESULT IN ELECTROSTATIC LATENT IMAGE, D. DEVELOPING SAID ELECTROSTATIC LATENT IMAGE WITH ELECTROSCOPIC MARKNG MATERIAL, E. TRANSFERRING SAID MARKING MATERIAL IN IMAGE FORMATION TO A FIRST COPY SHEET, F. REJUVENATING SAID ELECTROSTATIC LATENT IMAGE ON SAID EXPOSED LAYER SURFACE BY DEPOSITING THEREON ELECTROSTATIC CHARGES OF SAID SECOND SENSITIZING POLARITY, G. DEVELOPING SAID REJUVENATED ELECTROSTATIC LATENT IMAGE WITH ELECTROSCOPIC MARKING MATERIAL H. TRANSFERRING SAID MARKING MATERIAL IN IMAGE FORMATION TO A SECOND COPY SHEET, AND I. REPEATING SAID REJUVENATING DEVELOPING AND TRANSFERRING STEPS IN SEQUENCE TO PRODUCE FURTHER MULTIPLE COPIES FROM SAID ELECTROSTATIC LATENT IMAGE.