Patents by Inventor Bernard D. Lea

Bernard D. Lea 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).

  • Dry silver photo-sensitive compositions
    Patent number: 4197131
    Abstract: Dry silver photo-sensitive compositions comprising an intimate mixture of a substantially light-insensitive silver compound which upon reduction gives a visible change and sufficient of a silver halide to catalyse said reduction to give a visible change in those areas where the silver halide has been exposed to light and when the mixture is heated in the presence of a reducing agent, and as a yellow acutance dye a 1-alkyl-4-nitro-methylene-quinolane, the alkyl substituent containing 1 to 4 carbon atoms.
    Type: Grant
    Filed: November 29, 1978
    Date of Patent: April 8, 1980
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bernard D. Lea, Jack E. Reece