Patents Examined by Akim Ullah
  • Polyimide waveguides as optical sensors
    Patent number: 5094517
    Abstract: The invention relates to a polyimide waveguide which is used as an optical sensor for the quantitative determination of liquids in the vapor phase, as well as for the determination of NH.sub.3, "NH.sub.4 OH", NO.sub.2 and N.sub.2 O.sub.5. The polyimide waveguide is composed of a cover layer, one or two layers of a polyamide-imide or a perfluorinated polyimide and a substrate.
    Type: Grant
    Filed: August 10, 1990
    Date of Patent: March 10, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Hilmar Franke
  • Optical telephone wire
    Patent number: 4993795
    Abstract: An optical telephone wire comprising an optical conductor having a first covering of a circular cross-section and a messenger cable having a second covering of rectangular cross-section with one set of sides of the two sets of parallel sides of the second covering being longer than the diameter of the first convering and with the first and second coverings being integrally juxtaposed along their longitudinal axes so that spaces exist between the other set of sides of the second covering and the circular surface of the first covering.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: February 19, 1991
    Inventor: Masahiko Okura