Patents by Inventor Ann L. Verbeeck

Ann L. Verbeeck has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5601969
    Abstract: A method for the preparation of silver halide tabular emulsion grains, containing at least 75 % chloride, wherein at least 50 % of the total projected area of all the grains is provided by the tabular grains, and wherein the tabular grains exhibit an average aspect ratio of at least 5:1, an average thickness not greater than 0.5 micron and an average diameter of at least 0.6 micron. The method comprisespreparing a dispersion medium containing a gelatino-peptizer, and a compound ##STR1## wherein Z represents the atoms necessary to form a fused on aromatic carbocyclic or heterocyclic, unsubstituted or substituted ring, e.g., substituted with alkyl, alkenyl, aryl, alkoxy, hydroxy, mercapto, carboxy, amino or halogen, R is hydrogen or a substituent as defined for ring Z; n is 1 or 0, and Q represents carbon in which case n=1, or Q represents nitrogen, in which latter case n =0; in a concentration ranging from 10.sup.-4 to 10.sup.-2 molar. The pH of the medium is adjusted to between 5.0 and 9.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: February 11, 1997
    Assignee: Agfa-Gevaert, N.V.
    Inventor: Ann L. Verbeeck
  • Patent number: 5286621
    Abstract: A method is disclosed for the preparation of silver halide tabular emulsion grains, containing at least 75% chloride, wherein at least 50% of the total projected area of all the grains is provided by said tabular grains, and wherein said tabular grains exhibit an average aspect ratio of at least 5:1, an average thickness not greater than 0.5 micron and an average diameter of at least 0.6 micron, by a process comprising the following steps:(1) preparing a dispersion medium containing a gelatino-peptizer, and performing the precipitation of the silver halide grains under the following conditions:(a) the chloride ion concentration in the dispersion medium is lower than 0.15 molar at the start of the precipitation and remains lower than 0.15 molar during the whole precipitation, and pH is maintained between 5.0 and 9.
    Type: Grant
    Filed: August 26, 1992
    Date of Patent: February 15, 1994
    Assignee: Agfa-Gevaert, N.V.
    Inventor: Ann L. Verbeeck