Patents by Inventor Frederick Charles Derks

Frederick Charles Derks 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: 6291154
    Abstract: A silver halide photographic element, and a method of making such an element, comprising a tabular grain silver halide emulsion containing at least one green spectral sensitizing dye of formula I, and at least one green spectral sensitizing dye of formula II: wherein R1 and R2 may be the same or different and are selected from substituted or unsubstituted C1 or C2 alkyl, substituted or unsubstituted C1 or C2 alkoxy, halogen, substituted or unsubstituted amido, or carbamoyl or substituted or unsubstituted aryl, provided that R1 and R2 are not both aryl, and the benzo back rings may optionally be further substituted; X3 is a substituted or unsubstituted C1 to C3 alkyl or alkenyl; X1 and X2 are acid or acid salt substituted C1 to C6 alkyl or alkenyl which may be further substituted or unsubstituted; M+ is a positive ion as required to balance the charge; where R3 and R4 may be the same or different and represent substituted or unsubstituted alkyl or alkenyl of 1 to 4 c
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: September 18, 2001
    Assignee: Eastman Kodak Company
    Inventors: Anthony Adin, Frederick Charles Derks, Melvin Michael Kestner, Steven George Link
  • Patent number: 5965345
    Abstract: A method of sensitizing a silver halide emulsion comprises the steps of:a) forming a co-dispersion of a first sensitizing dye and a second sensitizing dye in an aqueous medium, wherein the peak absorptance of the second dye is at least 10 nm different from the peak absorptance of the first dye, and wherein the ratio of the first dye to the second dye is from about 0.1 to 20; andb) incorporating the resulting co-dispersion in a silver halide emulsion.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: October 12, 1999
    Assignee: Eastman Kodak Company
    Inventors: Steven George Link, John William Boettcher, Frederick Charles Derks, Heidi Melissa Viterise
  • Patent number: 5723280
    Abstract: A silver halide photographic element comprises a silver halide emulsion layer sensitized with a sensitizing dye of Formula I: ##STR1## wherein each of X.sub.1 and X.sub.2 is an oxygen atom, a sulfur atom, or a selenium atom, with the proviso that one of X.sub.1 and X.sub.2 is an oxygen atom and the other is a sulfur or selenium atom; V.sub.1 and V.sub.2 together or V.sub.2 and V.sub.3 together represent the atoms necessary to complete a fused benzene ring; each of V.sub.4 and V.sub.5 is independently a hydrogen or halogen atom, or an alkyl, alkoxy or aryl group; R.sub.1 is an acid substituted alkyl group; R.sub.2 is a 2-sulfoethyl group; and M is a counterion as necessary to balance the charge.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: March 3, 1998
    Assignee: Eastman Kodak Company
    Inventors: Steven George Link, James Kenneth Elwood, Frederick Charles Derks, Kenneth William Lowe