Patents by Inventor Kristen A. Hoff

Kristen A. Hoff 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).

  • Photohermographic emulsions having stable color forming developers
    Patent number: 4782010
    Abstract: The use of phenazine, phenoxazine and phenothiazine color forming developers in photothermographic dry silver emulsions provides a stable imaging system under both light and dark storage.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: November 1, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Roger A. Mader, David C. Weigel, Louis M. Leichter, Kristen A. Hoff
  • Barrier resin for photothermographic color separation
    Patent number: 4452883
    Abstract: A photothermographic color construction is disclosed, the construction having at least two color-forming layers comprising:a. a first, spectrally-sensitized, color-forming layer coated out of a solvent system selected from lower alkyl alcohols (up to 4 carbon atoms) ketones (up to 6 carbon atoms), aromatic hydrocarbons (up to 10 carbon atoms), or mixtures thereof,b. an upper, second, different, spectrally-sensitized color-forming layer coated out of a toluene or acetone solvent system, andc.
    Type: Grant
    Filed: May 17, 1983
    Date of Patent: June 5, 1984
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Robert A. Frenchik, Kristen A. Hoff