Patents by Inventor Biswa N. Ganguly

Biswa N. Ganguly 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: 5811841
    Abstract: A high voltage high current semiconductor switching device in which the tendency to incur premature electrical breakdown through carrier channels formed slightly below the surface of the semiconductor material is avoided. This avoidance occurs through use of a current dispersing electrically insulating element added at one extremity of the switching device structure. The added current dispersing element may be in the form of a thin oxide layer added at the anode end of the device in the case of a silicon embodiment of the invention. Tunneling conduction is believed to occur in this silicon dioxide layer and such conduction has the effect of dispersing the current through the silicon over a cross-sectional area sufficiently large to prevent the current filamentation, localized heating, thermal runaway and self destruction sequence often encountered in previous arrangements of higher energy semiconductor switches.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: September 22, 1998
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Biswa N. Ganguly, Brian A. Hibbeln
  • Patent number: 4655608
    Abstract: A novel laser beam deflection system and method for temperature measurement of combustion flames of known composition is described which comprises a thin wire for placement at a predetermined location within the flame; a pulsed laser source for directing a pulsed beam onto the wire for heating the wire and immediately surrounding gases of the flame to produce an acoustic pulse in the flame; a pair of probe laser sources for directing parallel probe beams through the flame in predetermined spaced relationship to each other and to the wire, and a pair of detectors and associated electronics for detecting the respective deflections of the probe beams resulting from interactions with the pulse and measuring the time difference between respective deflections of the probe beams to determine the speed of the acoustic pulse through the flame and the temperature of the flame from the speed determination.
    Type: Grant
    Filed: October 24, 1985
    Date of Patent: April 7, 1987
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Larry P. Goss, Dennis F. Grosjean, Benjamin Sarka, Jr., Sigmund W. Kizirnis, Biswa N. Ganguly
  • Patent number: 4429322
    Abstract: Glass fibers having an etchable or leachable core are used to fabricate glass nozzle arrays. A plurality of fibers are aligned in spaced parallel relationship with one another, and their major longitudinal portions are encapsulated with either a resin material or solder glass to form a block of material. This block is sliced orthogonally to the longitudinal axes of the fibers to form thin sections of nozzle arrays. After lapping and polishing, the inner cores of the glass fibers are etched out to form orifices. The use of solid core glass fibers prevents the nozzles from filling or becoming clogged with debris and dust from preceding forming operations.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: January 31, 1984
    Assignee: Mead Corporation
    Inventors: John L. Dressler, Biswa N. Ganguly, Bertram VanBreemen
  • Patent number: 4278999
    Abstract: An image scanner for scanning a document along a plurality of scan lines and providing a plurality of print control signal pulses in response to the image density of the document along the scan lines includes a means for projecting a moving document image onto a focal plane and a sensor array positioned in the focal plane. The sensor array includes columns of sensors extending parallel to the direction of image movement and a shift register associated with each column for sensors for shifting electrical outputs from the sensors in the direction of image movement. In a line copy mode of operation, the electrical outputs are shifted at the same rate at the rate of movement of the image such that the given pixel on the image is scanned sequentially by each of the sensors in a column. The electrical outputs are compared with a predetermined reference label to produce a print control signal.
    Type: Grant
    Filed: September 12, 1979
    Date of Patent: July 14, 1981
    Assignee: The Mead Corporation
    Inventors: Biswa N. Ganguly, Suresh C. Paranjpe