Patents Assigned to Computrol Systems, Ltd.
  • Patent number: 4354099
    Abstract: An electronic identification system for reading a pre-defined identifier code. A preferred application provides a credit card sized "identifier" which includes an array of electrical inductors, some of which are electrically connected in a selected pattern to define the identifier code. The identifier may be positioned closely proximate to a substantially identical inductor array included in a "reader" so that each identifier inductor is centered over a corresponding reader inductor. An alternating current is applied to each reader inductor in turn to induce an electromagnetic field in the region surrounding the driven inductor. The electromagnetic field so produced induces a voltage across the identifier inductor centered over the driven reader inductor. If that identifier inductor is electrically connected to another identifier inductor(s) a current will flow in the other inductor(s) and a second electromagnetic field will be generated in the region(s) surrounding the connected inductor(s).
    Type: Grant
    Filed: June 20, 1980
    Date of Patent: October 12, 1982
    Assignee: Computrol Systems, Ltd.
    Inventors: David J. Rayment, Hendrik R. Kruger