Direct positive photographic emulsion

Claim 1

THE PROCESS FOR PRODUCING, IN THE ABSENCE OF GELATIN, SILVER HALIDE GRAINS IN A RELATIVELY PURE CONDITION FOR MIXING WITH GELATIN IN A RELATIVELY PURE CONDITION FOR SION, WHICH COMPRISES MIXING TOGETHER IN AN AQUEOUS SOLUTION A SOLUBLE SILVER HALIDE AN AMMONIUM HYWITH HALIDE TO FORM SILVER HALIDE AND AMMONIUM HYDROXIDE IN AN AMOUNT SUFFICIENT TO SOLUBILIZE THE SILVER PRESENT AS THE SILVER AMMONIA COMPLES AG(NH3)2OH, A HALIDE COMPOUND CAPABLE OF REACTING WITH SILVER TO PRODUCE SILVER HALIDE, THE SAID HALIDE COMPOUND BEING IN AN AMOUNT AT LEAST 40% GREATER THAN THE AMOUNT STOICHIOMETRICALLY REQUIRED TO PRECIPITATE SILVER HALIDE, AND AN ACCELERATOR SELECTED FROM THE GROUP CONSISTING OF THIOUREA, TANNIN AND CUPRIC OXIDE PROMOTING FORMATION OF SILVER HALIDE GRAINS, SAID SOLUTION COMPRISING OF THE SAID INGREDIENTS AND WATERS, THEREBY OBTAINING A PRECIPATE OF SILVER HALIDE GRAINS, SEPARATING THE GRAINS FROM THE RESIDUAL SOLUTION, AND THEN MIXING THE GRAINS WITH AN AQUEOUS GELATIN SOLUTION.