Abstract:
IN THE PARTICULAR EMBODIMENTS OF THE INVENTION DESCRIBED HEREIN, ELECTROSTATIC CHARGE IMAGES ARE FORMED ON THE ADJACENT ENGAGING SURFACE OF A POTOCONDUCITVE INSULATING LAYER AND ANOTHER INSULATING LAYER BY OPTICAL EXPOSURE THROUGH THE PHOTOCONDUCTIVE INSULATING LAYER. IN ONE EMBODIMENT THE LAYERS ARE DISPOSED ON THE OUTSIDE SURFACES OF FIRST AND SECOND ROTATING DRUMS, RESPECTIVELY, AND A LIGHT SOURCE WITHIN ONE DRUM PROJECTS THE IMAGE OF AN ORIGINAL DISPOSED ON THE INNER SURFCE OF THE DRUM TO THE PHOTOCONDUCTIVE INSULATING LAYER DISPOSED ON THE OUTER SURFACE THEREOF. ELECTROSTTIC CHARGE IMAGES ARE PRODUCED ON THE DRUM SURFACES AS A RESULT OF A POTENTIAL DIFFERENCE APPLIED ACROSS THEM AND THE CHARGE IMAGES ARE MOVED BY DRUM ROTATION TO A DEVELOPMENT ZONE WHEREIN THE IMAGES ARE RENDERED VISIBLE BY LIQUID OR POWDERED DEVELOPER. IN ANOTHER EMBODIMENT THE ELECTROSTATIC CHARGE IMAGE IS TRANSFERRED FROM THE INSULATING DRUM TO A FURTHER INSULATING DRUM UPON WHICH IT IS MOVED THROUGH A DEVELOPMENT ZONE.