Patents by Inventor Roger H. Piggin

Roger H. Piggin 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: 6573021
    Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a combination of two or more hydrazide nucleating agents in the emulsion layer and/or a hydrophilic colloid layer, characterized in that the combination comprises a nucleating agent(s) of formulae (I) and/or (I) with a nucleator of formula (III), in which the nucleating agent of formula (I) comprises (a) two nicotinamide moieties, which may be the same or different, which are linked by a linking group, and (b) a hydrazide moiety linked to only one of those nicotinamide moieties; the nucleating agent of formula (II) comprises a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises a hydrazide moiety and a nicotinamide moiety; and the nucleating agent of formula (III) comprises an aryl sulfonamido aryl hydrazide.
    Type: Grant
    Filed: January 7, 2002
    Date of Patent: June 3, 2003
    Assignee: Eastman Kodak Company
    Inventors: Julie Baker, Ian Barford, Philip J. Coldrick, Dawn J. Jenkins, Roger H. Piggin
  • Publication number: 20020192589
    Abstract: The invention relates to an ultrahigh contrast photographic material comprising a support bearing a silver halide emulsion layer, containing a combination of two or more hydrazide nucleating agents in the emulsion layer and/or a hydrophilic colloid layer, characterized in that the combination comprises a nucleating agent(s) of formulae (I) and/or (I) with a nucleator of formula (III), in which the nucleating agent of formula (I) comprises (a) two nicotinamide moieties, which may be the same or different, which are linked by a linking group, and (b) a hydrazide moiety linked to only one of those nicotinamide moieties; the nucleating agent of formula (II) comprises a dimeric molecule comprising two monomers linked by a linking group, each monomer of which (a) may be the same or different and (b) comprises a hydrazide moiety and a nicotinamide moiety; and the nucleating agent of formula (III) comprises an aryl sulfonamido aryl hydrazide.
    Type: Application
    Filed: January 7, 2002
    Publication date: December 19, 2002
    Applicant: Eastman Kodak Company
    Inventors: Julie Baker, Ian Barford, Philip J. Coldrick, Dawn J. Jenkins, Roger H. Piggin
  • Patent number: 6187520
    Abstract: A high contrast photographic material free from nucleating agents comprising a support bearing a silver halide emulsion layer comprising silver halide grains and a hydrophilic colloid having a silver:hydrophilic colloid ratio above 1.9, and containing a density enhancing amine compound in the emulsion layer or an adjacent hydrophilic colloid layer wherein at least 60% of the silver halide grains are spectrally sensitized. A photographic image can be formed from the imagewise exposed material by a method comprising developing the exposed material for a time no longer than 25 seconds at a temperature no greater than 35° C.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: February 13, 2001
    Assignee: Eastman Kodak Company
    Inventors: Julia Pich, Roger H. Piggin, Mark L. Magill
  • Patent number: 5985509
    Abstract: A high contrast photographic material comprises a support bearing a silver halide emulsion layer. This material is free from nucleating agents and has a silver:gelatin ratio greater than 1. The emulsion layer comprises silver halide grains that are spectrally sensitized. Moreover, the material contains a density enhancing amine compound in the emulsion layer or in an adjacent hydrophilic colloid layer. The spectrally sensitized silver halide grains comprise one grain population sensitized to radiation of a particular wavelength region, and one or more additional grain populations sensitized to radiation of a different wavelength region.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: November 16, 1999
    Assignee: Eastman Kodak Company
    Inventors: Allison Hazel C. Dale, Roger H. Piggin
  • Patent number: 5589318
    Abstract: A high-contrast photographic material, adapted for use in the field of graphic arts, includes a hydrazide nucleating agent and comprises a silver halide emulsion layer containing silver halide grains which are spectrally sensitized with a non-desorbing sensitizing dye and silver halide grains which are not spectrally sensitized. Preferably, the photographic material also contains a booster compound which enables it to be processed in a developer having a pH of below 11.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: December 31, 1996
    Assignee: Eastman Kodak Company
    Inventors: Allison Hazel C. Dale, Roger H. Piggin, Richard A. Hallett, Paul R. McIntyre
  • Patent number: 5512415
    Abstract: A high-contrast photographic element, adapted for use in the field of graphic arts, includes a hydrazide nucleator and an amine booster and comprises a silver halide emulsion layer which is capable of forming a latent image under conditions of use and a second silver halide emulsion layer which is not capable of forming a latent image under conditions of use.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: April 30, 1996
    Assignee: Eastman Kodak Company
    Inventors: Allison H. C. Dale, Roger H. Piggin, Michael B. Ledger, David Beaumond
  • Patent number: 5061616
    Abstract: A process is disclosed for the preparation of a tabular grain silver bromoiodide emulsion in which silver bromoiodide laminae are formed on the major faces of the tabular grains. The sensitivity of the emulsion as a function of pressure applied is rendered more nearly constant by forming the silver bromoiodide laminae on the major faces of the tabular grains within a pAg and temperature range defined by Curve A in FIG. 1. The laminae are formed by first precipitating iodide as a silver salt at peripheral sites on the tabular grains and then precipitating silver bromoiodide onto the major faces of the host tabular grains with the primary source of iodide being the previously deposited iodide. The emulsions produced exhibit high sensitivity to exposing radiation and reduced sensitivity to localized pressure.
    Type: Grant
    Filed: October 4, 1989
    Date of Patent: October 29, 1991
    Assignee: Eastman Kodak Company
    Inventors: Roger H. Piggin, Philip J. Zola, Ming J. Lin
  • Patent number: 5061609
    Abstract: A process is disclosed for the preparation of a tabular grain silver bromoiodide emulsion in which silver bromoiodide laminae are formed on the major faces of the tabular grains. The sensitivity of the emulsion as a function of pressure applied is rendered more nearly constant by forming the silver bromoiodide laminae on the major faces of the tabular grains. The silver bromoiodide laminae are formed on the major faces of the tabular grains with an iodide content higher than that of the host emulsion, and thereafter, within the pAg and temperature boundaries defined by Curve A in FIG. 1, bromide is deposited as a silver salt with the addition of iodide being limited or absent.
    Type: Grant
    Filed: October 4, 1989
    Date of Patent: October 29, 1991
    Assignee: Eastman Kodak Company
    Inventors: Roger H. Piggin, Colin J. Bishop
  • Patent number: 4433048
    Abstract: Radiation-sensitive emulsions are disclosed comprised of a dispersing medium and silver bromoiodide grains. These emulsions contains tabular silver bromoiodide grains having a lower proportion of iodide in a central region than in a laterally displaced region, a thickness of less than 0.3 micron, and a diameter of at least 0.6 micron. These tubular grains exhibit an average aspect ratio of greater than 8:1 and account for at least 50 percent of the total projected area of the silver bromoiodide grains.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: February 21, 1984
    Assignee: Eastman Kodak Company
    Inventors: John C. Solberg, Roger H. Piggin, Herbert S. Wilgus