Method of electrophotographically manufacturing a television screen using hygroscopic material

Claim 1

A METHOD OF ELECTROPHOTOGRAPHICALLY MANUFACTURING A DISPLAY SCREEN OF A COLOR TELEVISION DISPLAY TUBE COMPRISING A SHADOW MASK AND A FACE PANEL, SAID METHOD COMPRISING THE STEP OF: A. PROVIDING SAID FACE PANEL COMPRISING A FIREABLE CONDUCTIVE LAYER DISPOSED THEREON AND A FIREABLE PHOTOCONDUCTIVE LAYER DISPOSED ON SAID CONDUCTIVE LAYER; B. PROVIDING FIRST PHOSPHOR PARTICLES COMPRISING AN OUTER LAYER OF A HYGROSCOPIC MATERIAL WHICH IS ELECTRICALLY CONDUCTIE IN A MOIST CONDITION; C. PROVIDING A FIRST PATTERN OF PHOSPHOR REGIONS AT SAID FACE PANEL BY UNIFORMLY ELECTROSTATICALLY CHARGING SAID PHOTOCONDUCTIVE LAYER AND SELECTIVELY DISCHARGING SAID PHOTOCONDUCTIVE LAYER BY EXPOSING SAID PHOTOCONDUCTIVE LAYER THROUGH A SHODOW MASK, THEREBY FORMING A LATENT CHARGE IMAGE WHICH COMPRISES CHARGES IN THE REGIONS CORRESPONDING TO THE SAID FIRST PATTERN AND THEN DEPOSITING ON THE SAID CHARGE IMAGE AND FROM AN INSULATING DEVELOPING LIQUID, FIRST PHOSPHOR PARTICLES CHARGED WITH OPPOSITE SPONDING TO THE SAIDLATENT CHARGE IMAGE; D. RENDERING SAID HYGROSCOPIC MATERIAL OF SAID FIRST PHOSPHOR PARTICLES IN A MOIST CONDITION; E. THEN REPEATING STEP (C) ABOVE WITH SECOND PHOSPHOR PARTICLES TO PROVIDE SECOND PHOSPHOR REGIONS AT SAID FACE PANEL; F. RENDERING SAID HYGROSCOPIC MATERIAL ON SAID FACE PANEL IN A DRY CONDITION; G. FOLLOWING STEP (F) PROVIDING A LIGHT-ABSORBING LSAYER BETWEEN SAID PHOSPHOR REGIONS BY UNIFORMLY ELECTROSTATICALLY CHARGING SAID PHOTOCONDUCTIVE LAYER WITH SAID PHOSPHOR REGIONS, SELECTIVELY DISCHARGING REGIONS OF SAID PHOTOCONDUCTIVE LAYER AND SAID DEPOSITED PHOSPHOR REGIONS BY UNIFORMLY EXPOSING SAID PHOTOCONDUCTIVE LAYER WITH THE SAID PHOSPHOR REGIONS, AND DEPOSING BETWEEN THE CHARGED PHOSPHOR REGIONS AND FROM AN INSULATING DEVELOPING LIQUID, LIGHT-ABSORBING PARTICLES CHARGED WITH THE SAME POLARITY AS SAID PHOTOCONDUCTIVE LAYER, AND H. FIRING THE FACE PANEL TO REMOVE SAID CONDUCTIVE LAYER AND SAID PHOTOCONDUCTIVE LAYER.

Claim 2

A METHOD OF ELECTROPHOTOGRAPHICALLY MANUFACTURING A DISPLAY SCREEN OF A COLOR TELEVISION DISPLAY TUBE COMPRISING A SHADOW MASK AND A FACE PANEL, SAID METHOD COMPRISING THE STEP OF: A. PROVIDING SAID FACE PANEL COMPRISING A FIREABLE CONDUCTIVE LAYER DISPOSED THEREON AND A FIREABLE PHOTOCONDUCTIVE LAYER DISPOSED ON SAID CONDUCTIVE LAYER; B. PROVIDING FIRST PHOSPHOR PARTICLES COMPRISING AN OUTER LAYER OF A HYGROSCOPIC MATERIAL WHICH IS ELECTRICALLY CONDUCTIE IN A MOIST CONDITION; C. PROVIDING A FIRST PATTERN OF PHOSPHOR REGIONS AT SAID FACE PANEL BY UNIFORMLY ELECTROSTATICALLY CHARGING SAID PHOTOCONDUCTIVE LAYER AND SELECTIVELY DISCHARGING SAID PHOTOCONDUCTIVE LAYER BY EXPOSING SAID PHOTOCONDUCTIVE LAYER THROUGH A SHODOW MASK, THEREBY FORMING A LATENT CHARGE IMAGE WHICH COMPRISES CHARGES IN THE REGIONS CORRESPONDING TO THE SAID FIRST PATTERN AND THEN DEPOSITING ON THE SAID CHARGE IMAGE AND FROM AN INSULATING DEVELOPING LIQUID, FIRST PHOSPHOR PARTICLES CHARGED WITH OPPOSITE SPONDING TO THE SAIDLATENT CHARGE IMAGE; D. RENDERING SAID HYGROSCOPIC MATERIAL OF SAID FIRST PHOSPHOR PARTICLES IN A MOIST CONDITION; E. THEN REPEATING STEP (C) ABOVE WITH SECOND PHOSPHOR PARTICLES TO PROVIDE SECOND PHOSPHOR REGIONS AT SAID FACE PANEL; F. RENDERING SAID HYGROSCOPIC MATERIAL ON SAID FACE PANEL IN A DRY CONDITION; G. FOLLOWING STEP (F) PROVIDING A LIGHT-ABSORBING LSAYER BETWEEN SAID PHOSPHOR REGIONS BY UNIFORMLY ELECTROSTATICALLY CHARGING SAID PHOTOCONDUCTIVE LAYER WITH SAID PHOSPHOR REGIONS, SELECTIVELY DISCHARGING REGIONS OF SAID PHOTOCONDUCTIVE LAYER AND SAID DEPOSITED PHOSPHOR REGIONS BY UNIFORMLY EXPOSING SAID PHOTOCONDUCTIVE LAYER WITH THE SAID PHOSPHOR REGIONS, AND DEPOSING BETWEEN THE CHARGED PHOSPHOR REGIONS AND FROM AN INSULATING DEVELOPING LIQUID, LIGHT-ABSORBING PARTICLES CHARGED WITH THE SAME POLARITY AS SAID PHOTOCONDUCTIVE LAYER, AND H. FIRING THE FACE PANEL TO REMOVE SAID CONDUCTIVE LAYER AND SAID PHOTOCONDUCTIVE LAYER.