Patents by Inventor Rene Omer Duville

Rene Omer Duville 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: 4108661
    Abstract: A photographic material is described for making positive images by reversal processing, the material comprising a support and a silver halide Lippmann-emulsion layer the average silver halide grain-size of which is less than 100 nm wherein the grains have been chemically sensitized to fog so that a test portion of the emulsion when coated on a support at a coverage of silver halide corresponding to from about 3 g to about 7 g of silver nitrate per sq.m. gives a density between about 0.20 and about 0.70 upon development without exposure for 6 min at 20.degree. C in a developer of the composition:Hydroquinone: 16.5 gPotassium bromide: 1.7 gSodium salt of EDTA: 1.7 gPotassium metabisulphite: 40 g1-phenyl-5-mercaptotetrazole: 35 gSodium hydroxide and water to make: 1 liter at pH 11.
    Type: Grant
    Filed: December 3, 1976
    Date of Patent: August 22, 1978
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Willy Joseph Vanassche, Herman Adelbert Philippaerts, Rene Omer Duville, Francois Leon Schelfaut