Patent ID: 6387586
Filing Date: 2002-05-14
Classification: G03C

Abstract:
A high contrast radiographic silver halide film comprising a support having first and second major surfaces and that is capable of transmitting X-radiation,said film having disposed on said first major support surface, two or more hydrophilic colloid layers including first and second silver halide emulsion layers, and on said second major support surface, two or more hydrophilic colloid layers including third and fourth silver halide emulsion layers, said first and third silver halide emulsion layers being closer to the support than said second and fourth silver halide emulsion layers, respectively, each of said first, second, third and fourth silver halide emulsion layers comprising silver halide tabular grains that (a) have the same or different composition in each silver halide emulsion layer, (b) account for at least 50% of the total grain projected area within each silver halide emulsion layer, (c) have an average thickness of less than 0.3 &mgr;m, and (d) have an average aspect ratio of greater than 5, all hydrophilic layers of the film being fully forehardened and wet processing solution permeable for image formation within 45 seconds, said first and third silver halide emulsion layers comprising at least one particulate dye that is (a) capable of absorbing radiation to which said silver halide emulsions are sensitive, (b) present in an amount sufficient to reduce crossover to less than 15%, and (c) capable of being substantially decolorized during wet processing, said first and third silver halide emulsion layers also comprising a rhodium dopant for said tabular silver halide grains, said rhodium dopant being present in each silver halide emulsion layer in an amount, independently, of from about 1Ã—10âˆ’5 to about 5Ã—10âˆ’5 mole per mole of silver in each emulsion layer, the ratio of photographic speed of said first silver halide emulsion layer to said second silver halide emulsion layer and the ratio of said third silver halide emulsion layer to said fourth silver halide emulsion layer being independently greater than 0.3 logE, said film being capable of providing an image that has visually adaptive contrast and a peak gamma >3.1 while maintaining gammas >1.0 out into the toe of a D vs. logE sensitometric curve to a value of âˆ’0.9 logE.