Patents Assigned to Tracor Northern, Inc.
  • Patent number: 4863252
    Abstract: The objective lens in a confocal tandem scanning reflected light microscope is movable relative to the specimen stage by piezoelectric actuators controlled by a closed-loop feedback control system having eddy current sensors to detect lens position. Position control input is either manual or automatic.
    Type: Grant
    Filed: February 11, 1988
    Date of Patent: September 5, 1989
    Assignee: Tracor Northern, Inc.
    Inventors: Jon J. McCarthy, James F. Aeschbach
  • Patent number: 4802748
    Abstract: A Tandem Scanning Microscope is disclosed using a modified Nipkow disk design. With this scanning system, scanning is performed using many apertures at once and using one disk for both image and illumination scanning. The apertures in the disk are in an annular pattern of spiral arms. Each aperture is located along a spiral arm at the end of a radius vector. Relative aperture locations are established in accordance with a mathematical relationship.
    Type: Grant
    Filed: December 14, 1987
    Date of Patent: February 7, 1989
    Assignee: Tracor Northern, Inc.
    Inventors: Jon J. McCarthy, John D. Fairing, Jeffrey C. Buchholz
  • Patent number: 4288692
    Abstract: X-ray spectral data are normalized to beam current by basing data accumulations upon a fixed beam current integral rather than a fixed acquisition time. A current proportional to beam current is obtained from an aperture in an electron column instrument to provide a continuous monitor of beam current during data accumulation. The current is applied to a digital current integrator producing output pulses at a frequency proportional to the current. Connected to the digital current integrator is a one-shot producing a pulse of fixed width for each integrator pulse. The interval between one-shot pulses is defined as "delay time," and a signal representative of that time interval is produced and utilized to control the actual analysis time such that a prescribed beam current integral is obtained.
    Type: Grant
    Filed: August 6, 1979
    Date of Patent: September 8, 1981
    Assignee: Tracor Northern, Inc.
    Inventors: Frederick H. Schamber, Jon J. McCarthy