The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 1998
Filed:
Jul. 09, 1996
Luc Renaud Gourlaouen, Givry, FR;
Gerard Amede Friour, Chalon-Sur-Saone, FR;
Pierre-Henri Jezequel, Givry, FR;
Frederic Xavier Jordi, Saint Vincent En Bresse, FR;
Jean-Pascal Francis Lebrat, Chalon-Sur-Saone, FR;
Eastman Kodak Company, Rochester, NY (US);
Abstract
A photosensitive emulsion is disclosed comprised of a dispersing medium and silver halide grains containing at least 80 mole percent bromide, based on silver, wherein at least 50% of the projected area of said silver halide grains is accounted for by tabular grains free of twin planes having {100} parallel major faces, said emulsion being chemically sensitized and having a reciprocity failure of less than 35 sensitivity units between exposures of respectively 10.sup.-5 seconds and 100 seconds. The emulsion can be employed as a latent image forming emulsion in a photographic element. The emulsion can be prepared by a process preparing a silver bromide photosensitive emulsion, comprising the following essential steps: (a) a nucleation step whereby a fine-grain emulsion with a pAg of between 4 and 6.5 and a pH of between 2 and 5 is precipitated, while maintaining, at the start of the nucleation and for a short time, a stoichiometric excess concentration of silver corresponding to a pAg of less than 5, and (b) a physical ripening step, at a pAg of between 8 and 9.5 and a pH of between 6 and 8.