Patents by Inventor Gerald Allan Campbell

Gerald Allan Campbell 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: 4070189
    Abstract: Antistatic compositions comprising a highly crosslinked vinylbenzyl quaternary ammonium polymer and a hydrophobic binder are described. Elements, particularly photographic elements, having a layer of the antistatic compositions are also described. The compositions are characterized by a binder to antistatic polymer ratio of about 10:1 to 1:1. The compositions are highly conductive in thin layers and retain substantial conductivity at low relative humidity. Layers of the antistatic compositions are particularly useful for photographic elements because they can be contacted over a wide range of conditions with a hydrophilic layer without resulting in ferrotyping.
    Type: Grant
    Filed: October 4, 1976
    Date of Patent: January 24, 1978
    Assignee: Eastman Kodak Company
    Inventors: Richard Norman Kelley, Gerald Allan Campbell
  • Patent number: 4055429
    Abstract: A photographic element comprises a support, a silver halide emulsion layer and a layer containing a polymeric scavenger for development inhibitors. The movement of development inhibitor anions from layer to layer in a film, out of the film, or into the film from processing solutions, can be controlled by the presence of the polymeric scavenger layer.
    Type: Grant
    Filed: November 13, 1975
    Date of Patent: October 25, 1977
    Assignee: Eastman Kodak Company
    Inventors: Edmund Thompson Holmes, Gerald Allan Campbell