Patents by Inventor Hubertus W. H. M. Roncken

Hubertus W. H. M. Roncken 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).

  • Indirect electrophotographic process with a nitro-phenolsultonephthalein
    Patent number: 4054450
    Abstract: Fading of the light-sensitivity of a dye-sensitized photoconductive layer used repeatedly for image formation in indirect electrophotographic copying is avoided by employing a photoconductive layer sensitized by a nitro-substituted dye such as a nitro-fluorescein or a nitro-phenolsulfonephthalein.
    Type: Grant
    Filed: June 27, 1974
    Date of Patent: October 18, 1977
    Assignee: Oce-van der Grinten N.V.
    Inventors: Bauke Schoustra, Hubertus W. H. M. Roncken
  • Dye sensitized photoconductive material
    Patent number: 3951655
    Abstract: Electrophotographic sheet material comprising a dye-sensitized photoconductive layer is made resistant to fading of its light-sensitivity by incorporating in the photoconductive layer a nitro-substituted xanthene dye, e.g. safrosin.
    Type: Grant
    Filed: June 27, 1974
    Date of Patent: April 20, 1976
    Assignee: Oce-van der Grinten N.V.
    Inventors: Bauke Schoustra, Hubertus W. H. M. Roncken