Electrical photography

Claim 1

A METHOD FOR REPRODUCTION OF A GRAPHIC ORIGINAL COMPRISING PROJECTING THE GRAPHIC ORIGINAL UPON A PHOTOCONDUCTIVE COPY-SHEET COMPRISING A METAL LAYER UPON WHICH HAS BEEN BONDED THERETO A PHOTOCONDUCTIVE LAYER CONTAINING A COMPOUND SELECTED FROM AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF BUISMUTH TRIOXIDE, TITANIUM DIOXIDE, BARIUM TITANTE AND LEAD OXIDE WHICH UNDERGOES A CHANGE IN COLOR UPON REACTION WHEN SUBJECTED TO A HIGH POTENTIAL NEGATIVE ION BOMBARDMENT CREATED BY A CORONA DISCGHARGE OF AT LEAST 10,000 VOLTS TO PRODUCE A DIFFERENTIAL CONDUCTIVE PATTERN COMPRISING RELATIVELY NON-CONDUCTIVE AND RELATIVELY CONDUCTIVE AREAS ON THE SURFACE THEREOF CORRESPONDING TO SAID GRAPHIC ORIGINAL, ESTABLISHING A HIGH POTENTIAL GRADIENT OF AT LEAST 10,000 VOLTS BETWEEN SAID COPYSHEET CONTAINING SAID DIFFERENTIAL CONDUCTIVE PATTERN AND A NEGATIVE CORONA ELECTRODE IN THE PRESENCE OF AN INOIZABLE ATMOSPHERE CONSISTING ESSENTIALLY OF NORMALLY GASEOIS MATERIAL, SAID ELECTRODE IN THE PRESENCE OF AN IONIZABLE FROM SAID COPY-SHEET THAT SUBSTANTIALLY THE UNTIRE CONDUCTIVE AREAS OF SAID COPY-SHEET ARE BOMBARDED WITH NEGTIVELY CHARGED NORMALLY GASEOUS IONS, AND CONTINUING SAID BOMBARDMENT OF SAID COPY-SHEET EITH SAID NEGATIVELY CHARGED NORMALLY GASEOUS IONS FOR SUFFICIENT LENGTH OF TIME TO PRODUCE A VISIBLE REPRODUCTION OF SAID GRAPHIC ORIGINAL UPON THE SURFACE OF SAID COPY-SHEET.

Claim 2

A METHOD FOR REPRODUCTION OF A GRAPHIC ORIGINAL COMPRISING PROJECTING THE GRAPHIC ORIGINAL UPON A PHOTOCONDUCTIVE COPY-SHEET COMPRISING A METAL LAYER UPON WHICH HAS BEEN BONDED THERETO A PHOTOCONDUCTIVE LAYER CONTAINING A COMPOUND SELECTED FROM AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF BUISMUTH TRIOXIDE, TITANIUM DIOXIDE, BARIUM TITANTE AND LEAD OXIDE WHICH UNDERGOES A CHANGE IN COLOR UPON REACTION WHEN SUBJECTED TO A HIGH POTENTIAL NEGATIVE ION BOMBARDMENT CREATED BY A CORONA DISCGHARGE OF AT LEAST 10,000 VOLTS TO PRODUCE A DIFFERENTIAL CONDUCTIVE PATTERN COMPRISING RELATIVELY NON-CONDUCTIVE AND RELATIVELY CONDUCTIVE AREAS ON THE SURFACE THEREOF CORRESPONDING TO SAID GRAPHIC ORIGINAL, ESTABLISHING A HIGH POTENTIAL GRADIENT OF AT LEAST 10,000 VOLTS BETWEEN SAID COPYSHEET CONTAINING SAID DIFFERENTIAL CONDUCTIVE PATTERN AND A NEGATIVE CORONA ELECTRODE IN THE PRESENCE OF AN INOIZABLE ATMOSPHERE CONSISTING ESSENTIALLY OF NORMALLY GASEOIS MATERIAL, SAID ELECTRODE IN THE PRESENCE OF AN IONIZABLE FROM SAID COPY-SHEET THAT SUBSTANTIALLY THE UNTIRE CONDUCTIVE AREAS OF SAID COPY-SHEET ARE BOMBARDED WITH NEGTIVELY CHARGED NORMALLY GASEOUS IONS, AND CONTINUING SAID BOMBARDMENT OF SAID COPY-SHEET EITH SAID NEGATIVELY CHARGED NORMALLY GASEOUS IONS FOR SUFFICIENT LENGTH OF TIME TO PRODUCE A VISIBLE REPRODUCTION OF SAID GRAPHIC ORIGINAL UPON THE SURFACE OF SAID COPY-SHEET.