Patents by Inventor Martin J. Walker

Martin J. Walker 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).

  • Micromachined devices having microbridge structure
    Patent number: 5942791
    Abstract: A method of fabricating a microbridge structure for a thermal detector array comprises growing a planarising layer on a substrate, growing a ferroelectric material layer on the planarising layer and then etching the planarising layer away, either wholly or partially, to leave a ferroelectric microbridge having a uniform thickness. The planarising layer may be a sacrificial layer or may comprise a sacrificial layer as well as other layers.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: August 24, 1999
    Assignee: GEC-Marconi Limited
    Inventors: Nicholas M Shorrocks, Martin J Walker, Ralph Nicklin, Andrew D Parsons
  • Communication apparatus for hostile environments
    Patent number: 4491699
    Abstract: A dual communication system is disclosed including a microphone for mounting for use by a wearer of a protective face mask, the output signal from the microphone being communicated to both a speaker system for local, audible broadcast and to a transmitter for remote broadcast by radio signal.
    Type: Grant
    Filed: April 15, 1981
    Date of Patent: January 1, 1985
    Assignee: NL Industries, Inc.
    Inventor: Martin J. Walker