Patents by Inventor Martin R. Lambden

Martin R. Lambden 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: 4289925
    Abstract: Electrographic apparatus includes a transducer pad having a flexible membrane mounted over a base member with facing surfaces of the membrane and base member being electrically conductive and having electrical voltages applied thereto whereby to provide electrical signals representing the coordinates of a location at which pressure is applied to the flexible membrane locally by a pen or stylus, wherein in order to maintain an appropriate tension in the flexible membrane, the membrane is attached to and mounted on an outwardly tensioned rectangular frame member. The frame member may comprise separate frame elements and spring members forcing the elements away from one another. Alternatively, the frame member may be resilient and be inwardly compressed during the attaching thereto of the flexible membrane whereby the inherent resilience of the frame member subsequently tensions the flexible membrane.
    Type: Grant
    Filed: May 29, 1979
    Date of Patent: September 15, 1981
    Assignee: Quest Automation Limited
    Inventor: Martin R. Lambden
  • Patent number: 4129746
    Abstract: Electrographic apparatus, that is apparatus for obtaining electrical signals related to the movement of a point, such as a pen or stylus, over a pressure sensitive surface. The apparatus comprises a hand-supporting plate movable relative to the pressure sensitive surface to provide a convenient hand-rest during writing or drawing without the hand touching the pressure sensitive surface.
    Type: Grant
    Filed: May 2, 1977
    Date of Patent: December 12, 1978
    Assignee: Quest Automation Limited
    Inventor: Martin R. Lambden