David Kevin Dumont

US Patent:

56121750, Mar 18, 1997

Filed:

Jan 26, 1996

Appl. No.:

8/592169

Inventors:

Lyn M. Eshelman - Penfield NY
Paul J. Madigan - Rochester NY
Joseph C. Deaton - Rochester NY
David A. Dumont - Rochester NY
Michael G. Antoniades - Rochester NY
Sharon G. Johnston - Rochester NY

Assignee:

Eastman Kodak Company - Rochester NY

International Classification:

G03K 1035

US Classification:

430567

Abstract:

A radiation-sensitive spectrally sensitized tabular grain emulsion is disclosed which exhibits improved speed and contrast. The tabular grains have {111} major faces, contain greater than 70 mole percent bromide and up to 10 mole percent iodide, based on silver, account for greater than 90 percent of total grain projected area, and have an average equivalent circular diameter of at least 3. 5. mu. m. The tabular grains have latent image forming chemical sensitization sites on their surfaces including epitaxially deposited silver halide protrusions of a face centered cubic rock salt crystal lattice structure forming epitaxial junctions with the tabular grains. The protrusions are restricted to those portions of the tabular grains located nearest peripheral edges of and accounting for less than 10 percent of the {111} major faces of the tabular grains, accounting for less than 5 percent of total silver forming the tabular grains and protrusions, containing a silver chloride concentration at least 10 mole percent higher than that of the tabular grains, and contain at least 1 mole percent iodide, based on silver in the protrusions.