Patents Assigned to Societe Pyral
  • Magnetic recording device for providing security related information
    Patent number: 4303949
    Abstract: A magnetic recording device for providing security related information includes a magnetic base carrier having substantially uniform thickness and zone of increased or decreased thickness on the base carrier forming thickness increments. The thickness increments impart different magnetic characteristics to the recording device to amplitude modulate a magnetic signal recorded thereon and thereby provide security related information. Processes for the preparation and application of such a device are also disclosed.
    Type: Grant
    Filed: July 31, 1979
    Date of Patent: December 1, 1981
    Assignee: Societe Pyral
    Inventor: Roland Peronnet