Patents by Inventor William D. Westwood

William D. Westwood 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: 4969712
    Abstract: An edge emitting optoelectronic source is integrally formed on a surface of a semiconductor substrate. An optical waveguide is integrally formed on the same surface of the substrate adjacent to the source. The waveguide is aligned with the source for optical coupling of the source to the waveguide. The waveguide comprises an optical diverter for diverting at least a portion of any light propagating along the waveguide toward the source through a surface of the waveguide. An optoelectronic detector is secured to that surface of the waveguide through which light is diverted for receiving light diverted through that surface. The resulting optoelectronic apparatus is suitable for launching and detecting optical signals in large volume bidirectional optical fiber transmission systems.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: November 13, 1990
    Assignee: Northern Telecom Limited
    Inventors: William D. Westwood, Herman W. Willemsen, Michel I. Gallant, Richard P. Skillen
  • Patent number: 4528438
    Abstract: The end point in plasma etching is detected by monitoring the optical emission from the plasma, selecting a particular optical emission line and detecting a substantial variation in the intensity of the emission. This indicates a change in material being etched and thus the completion of etching of one material, or the beginning of etching of another material. It is also applicable to removing, or etching, photoresist material.
    Type: Grant
    Filed: January 7, 1983
    Date of Patent: July 9, 1985
    Assignee: Northern Telecom Limited
    Inventors: Robert G. Poulsen, Gerald M. Smith, William D. Westwood
  • Patent number: 4459739
    Abstract: A thin film transistor has a semiconductor layer, an insulating layer and source, drain and gate electrodes. The improvement comprises creating an enhanced conductivity layer in the semiconductor by ion implantation or diffusion on phased deposition. The benefits of the enhanced conductivity layer are that transistor action is obtained without the conventional annealing step and DC stability is much improved.
    Type: Grant
    Filed: December 13, 1982
    Date of Patent: July 17, 1984
    Assignee: Northern Telecom Limited
    Inventors: Frank R. Shepherd, William D. Westwood
  • Patent number: 4422090
    Abstract: A thin film transistor has a semiconductor layer, an insulating layer and source, drain and gate electrodes. The improvement comprises creating an enhanced conductivity layer in the semiconductor by ion implantation or diffusion on phased deposition. The benefits of the enhanced conductivity layer are that transistor action is obtained without the conventional annealing step and D.C. stability is much improved.
    Type: Grant
    Filed: May 26, 1981
    Date of Patent: December 20, 1983
    Assignee: Northern Telecom Limited
    Inventors: Frank R. Shepherd, William D. Westwood
  • Patent number: 4413883
    Abstract: A matrix multiplexed field effect display has switch devices at matrix crosspoints to provide a turn-on threshold for the field effect material. The switch devices are thin film metal-insulator-metal (MIM) switches. The display is operated at low current so that the MIM switches, which may be deposited on glass, do not degrade rapidly in use.
    Type: Grant
    Filed: December 3, 1980
    Date of Patent: November 8, 1983
    Assignee: Northern Telecom Limited
    Inventors: David R. Baraff, Nur M. Serinken, Richard W. Streater, Carla J. Miner, Robert J. Boynton, Blair K. MacLaurin, William D. Westwood
  • Patent number: 4392931
    Abstract: Using a sputter deposition system to reactively deposit a material such as an oxide, it is relatively easy to achieve either an oxygen-doped film with appreciable metallic content or an oxide film. However it is difficult with known systems to obtain an intermediate film having an accurately controlled resistivity, transparency, and composition, such films being of much use in semiconductor applications, in displays and in photovoltaic cells. It is now proposed that an apertured barrier be used to accurately fix the flow rate of target material to the substrate and in addition, that reactive gas flow be regulated and directed only to the immediate vicinity of the substrate. In this way the composition of the film can be accurately fixed. By establishing an r.f. field at the substrate, increased dissociation of the reactive gas can be achieved to render the gas more reactive and so enhance certain film properties such as transparency.
    Type: Grant
    Filed: March 31, 1981
    Date of Patent: July 12, 1983
    Assignee: Northern Telecom Limited
    Inventors: Shmuel Maniv, William D. Westwood
  • Patent number: 4366488
    Abstract: A terminal has a reciprocating print head bearing a series of linearly arranged, individually-magnetizable styli for printing on magnetic particle oriented paper. The terminal may be used as a printer, or as a display by combining the printer with an erasing head comprising a series of linearly arranged magnets which create a rotating magnetic field to erase the magnetic particle oriented paper when the erasing head is reciprocated. The print and erase heads are mounted on a common carriage. The terminal is cheap to manufacture and, if used as a printer, has the advantage of reusable paper. If used as a display, it required no refresh.
    Type: Grant
    Filed: April 2, 1980
    Date of Patent: December 28, 1982
    Assignee: Northern Telecom Limited
    Inventors: William D. Westwood, Steven Kos, Herman W. Willemsen
  • Patent number: 4275290
    Abstract: A thermally activated liquid ink printing head has a plurality of orifices in a wall of an ink reservoir, the ink retained in the orifices by surface tension. Electrical heating elements heat the ink in the orifices, the ink being caused to pass across to a paper sheet positioned adjacent to the orifices. The orifices may extend in a line across the head or may be in other predetermined patterns, such as for printing alpha-numerics a character at a time. The ink may be completely or partly vaporized. The heating current may flow through the ink.
    Type: Grant
    Filed: June 14, 1979
    Date of Patent: June 23, 1981
    Assignee: Northern Telecom Limited
    Inventors: Paolo Cielo, William D. Westwood
  • Patent number: 4166277
    Abstract: An electrostatic ink ejection printing head uses an ink reservoir having small holes in its wall, the ink retained within the holes by surface tension. An electrostatic field is produced at each hole, as required, to overcome the surface tension and cause the ink to move into contact with a paper sheet to produce a dot. The holes can be in any desired predetermined formation. An electrode can be positioned opposite each hole, the paper between electrode and hole, or an electrode can be formed around or on either side of each hole. The electrodes are pulsed as necessary.
    Type: Grant
    Filed: October 25, 1977
    Date of Patent: August 28, 1979
    Assignee: Northern Telecom Limited
    Inventors: Paolo Cielo, William D. Westwood
  • Patent number: 4164745
    Abstract: In a liquid ink printing system, ink is supplied to a reservoir at a constant pressure, and viscosity of ink in orifices in the reservoir wall is decreased by electrically heating the ink in the orifices. By this means the amount of ink deposited on a paper sheet moving past the orifices can be varied.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: August 14, 1979
    Assignee: Northern Telecom Limited
    Inventors: Paolo Cielo, William D. Westwood
  • Patent number: 4162502
    Abstract: A liquid ink printer uses electrostatic control of ink flow along paths defined by strips of hydrophilic material. The strips may be discontinuous, with a narrow gap across which ink is urged to flow by application of a voltage to an electrode, or a gate member may be pulled down onto a strip to prevent ink flow. In a further arrangement drops of ink are extracted from the ends of the strips and accelerated towards a printing position by an electrode pattern.
    Type: Grant
    Filed: May 5, 1978
    Date of Patent: July 24, 1979
    Assignee: Northern Telecom Limited
    Inventors: Paolo Cielo, William D. Westwood