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US 4,425,425 AGranted
Radiographic elements exhibiting reduced crossover
AssigneeEastman Kodak Company
InventorsThomas I. Abbott, Cynthia Jones
Life of this patent
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Abstract
Radiographic elements are disclosed comprised of first and second imaging portions separated by an interposed support capable of transmitting radiation to which the second imaging portion is responsive. At least the first imaging portion includes a silver halide emulsion in which high aspect ratio tabular silver halide grains are present. Spectral sensitizing dye is adsorbed to the surface of the tabular grains. Crossover can be improved in relation to the imaging characteristics.
Claims20
In a radiographic element comprised of
- first and second imaging means,
- at least said first imaging means including a silver halide emulsion comprised of a dispersing medium and radiation-sensitive silver halide grains, and
- a support interposed between said imaging means capable of transmitting radiation to which said second imaging means is responsive
- the improvement comprising said first imaging means containing
- tabular silver halide grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of greater than 8:1 accounting for at least 50 percent of the total projected area of said silver halide grains present in said silver halide emulsion and
- spectral sensitizing dye adsorbed to the surface of said tabular silver halide grains in an amount sufficient to substantially optimally sensitize said tabular grains.
3 more elements
In a radiographic element comprised of
- first and second silver halide emulsion layers each comprised of a dispersing medium and radiation-sensitive silver bromide or silver bromoiodide grains and
- a film support interposed between said emulsion layers capable of transmitting radiation to which said emulsion layers are responsive,
- the improvement comprising said emulsion layer containing
- substantially optimally chemically sensitized tabular silver bromide or silver bromoiodide grains having a thickness of less than 0.3 micron, a diameter of at least 0.6 micron, and an average aspect ratio of at least 12:1 accounting for at least 70 percent of the total projected area of said silver bromide or silver bromoiodide grains present in said silver halide emulsion layer and
- spectral sensitizing dye which exhibits a shift in hue as a function of adsorption being adsorbed to the surface of said tabular silver bromide or silver bromoiodide grains in an amount sufficient to substantially optimally sensitize said tabular grains.
2 more elements
In a radiographic element comprised of
- first and second silver halide emulsion layers each comprised of a dispersing medium and radiation-sensitive silver bromide or silver bromoiodide grains and
- a film support interposed between said emulsion layers capable of transmitting radiation to which said emulsion layers are responsive,
- the improvement comprising said emulsion layers containing
- substantially optimally chemically sensitized tabular silver bromide or silver bromoiodide grains having a thickness of less than 0.5 micron, a diameter of at least 0.6 micron, and an average aspect ratio of greater than 8:1 accounting for at least 50 percent of the total projected area of said silver bromide or silver bromoiodide grains present in said silver halide emulsion layers and
- blue spectral sensitizing dye which exhibits a shift in hue as a function of adsorption being adsorbed to the surface of said tabular silver bromide or silver bromoiodide grains in an amount sufficient to substantially optimally sensitize said tabular grains.
2 more elements
Dependencies are inferred from the claim text.