Patents by Inventor Paul J. H. Tummers

Paul J. H. Tummers 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: 4435493
    Abstract: A reusable electrophotographic element comprising a photoconductive layer containing sensitized zinc oxide particles and first and second binding agents that are incompatible is produced by employing as the first binding agent a macromolecular compound that has a higher affinity to zinc oxide than the second binding agent, is largely deposited on the zinc oxide, has an average molecular weight of at least 12,000 and is present in the photoconductive layer in an amount of 1.5 to 9% by weight calculated on the zinc oxide, with the second binding agent present in substantially larger amount. The photoconductive layer is formed of agglomerates of zinc oxide particles substantially enveloped in the first binding agent, which agglomerates have a diameter of between 2.5 and 6 .mu.m and are stuck together by portions of the second binding agent, thus providing a substantially porous photoconductive layer having a negative charge density of at most 1 m Coulomb per m.sup.2.
    Type: Grant
    Filed: December 10, 1981
    Date of Patent: March 6, 1984
    Assignee: Oce-Nederland B.V.
    Inventors: Jan A. de Putter, Paul J. H. Tummers