Patents by Inventor David Leslie Greenaway

David Leslie Greenaway 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).

  • Apparatus and method for producing an electrical signal responsive to handwriting characteristics
    Patent number: 4122435
    Abstract: The invention relates to a means and method for producing an electrical signal responsive to identifying characteristics of handwriting. The electrical signal is produced responsive to variations in writing pressure between a writing instrument and a ridged writing surface.
    Type: Grant
    Filed: October 11, 1977
    Date of Patent: October 24, 1978
    Assignee: LGZ Landis & GYR Zug Ag
    Inventor: David Leslie Greenaway
  • Multilayer identification card
    Patent number: 4119361
    Abstract: A multi-ply identification card for storage of machine-readable information includes optical markings disposed between protective layers. At least one of the protective layers can be penetrated by infrared light, and both are opaque to light of lesser wavelengths. The optical markings have a fine structure with at least 300 lines per mm and the protective layers are so connected to the optical markings that the markings are destroyed if one of the protective layers is removed.
    Type: Grant
    Filed: August 9, 1976
    Date of Patent: October 10, 1978
    Assignee: Landis & Gyr
    Inventor: David Leslie Greenaway