Process for developing electrostatic images and apparatus therefor

Claim 1

AN IMPROVED XEROGRAPHIC DEVELOPING METHOD WHEREIN A POSITIVELY CHARGED SUSPENSION OF FINELY-DIVIDED CHARCOAL POWDER PARTICLES IS PRESENTED TO AN ELECTROSTATIC LATENT IMAGE-BEARING SURFACE, SAID METHOD COMPRISING FORMING A GAS SUSPENSION OF SAID FINELY-DIVIDED CHARCOAL, FORCING SAID GAS SUSPENSION THROUGH A CAPILLARY TURBULENCE ZONE AT A RATE OF FLOW THERETHROUGH SUFFICIENT TO ACHIEVE TURBULENT FLOW IN CONTRADISTINCTION TO LAMINAR FLOW WHEREBY THE SUSPENDED CHARCOAL PARTICLES ARE DEAGGLOMERATED AND ARE ELECTROSTATICALLY CHARGED TO A POSITIVE POLARITY BY CONTACT WITH THE WALLS OF THE CAPILLARY ZONE, SAID WALLS CONSISTING OF A MINERAL SELECTED FROM THE GROUP CONSISTING OF SOAPSTONE, MONTMORILLONITE, HALLOYSITE, BENTONITE, SPODUMENE, RED SANDSTONE, SERPENTINE, PYROPHYLLITE, OLIGOCLASE, GREY SANDSTONE, AND QUARTZOSE SANDSTONE OF THE ARGILLACEOUS TYPE AND PRESENTING THE SUSPENSION OF SAID POSITIVELY CHARGED CHARCOAL PARTICLES FROM SAID TURBULENT ZONE TO THE ELECTROSTATIC LATENT IMAGE-BEARING SURFACE.