Direct-positive emulsion containing fogged, silver halide grains of silver iodide content
AssigneeAgfa-Gevaert
InventorsWilly J. Vanassche, Herman A. Pattyn, Erik Moisar, Sieghart Klotzer
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Abstract
Direct positive silver halide emulsions are provided which contain fogged silver halide grains the said grains being heterodisperse and containing silver iodide in an amount of more than 10 mole % and at most 20 mole % relative to the total amount of silver halide. The emulsions have increased sensitivity and reduced gradation which is suitable for continuous tone reproduction.
Claims14
Photographic material comprising at least one layer of a direct-positive radiation-sensitive emulsion containing fogged silver halide grains, wherein the silver halide grains are heterodisperse and irregular and have a grain size distribution so that at least 10% by weight of the silver halide grains have a diameter, which deviates for at least 40% from the mean grain diameter and wherein the silver halide of the grains has a silver iodide content of more than 10 mole % and at most about 20 mole % relative to the total amount of silver halide.
Method of producing direct-positive images, which comprises image-wise exposing and subsequently surface developing a direct-positive material containing fogged silver halide grains wherein the silver halide grains are heterodisperse and irregular and have a grain size distribution so that at least 10% by weight of the silver halide grains have a diameter, which deviates for at least 40% from the mean grain diameter and wherein the silver halide of the grains has a silver iodide content of more than 10 mole % and at most about 20 mole % relative to the total amount of silver halide.
Dependencies are inferred from the claim text.