Patents by Inventor William W. Marshall

William W. Marshall 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: 4841404
    Abstract: An electrical circuit for providing electrical energy to an electric motor which operates a liquid pump. The motor and the pump are adapted to be submerged in the liquid which is pumped by the pump. The circuit disclosed herein senses the phase angle between the current and the voltage applied to the electric motor. When the phase angle indicates that the motor is operating without a load, the circuit deenergizes the electric motor. Thus, the motor and the liquid pump are protected against damage. Recognizing that harmonics may exist in the current flow through the motor, the circuit provides for obtaining a filtered signal proportional to the fundamental frequency of the current flowing through the motor. Thus, an accurate measurement of the loading of a motor is obtained. The circuitry of this invention also provides an accurate method of compensation for applied line voltage variations, so that a change in the applied line voltage does not produce a false indication that the motor loading has changed.
    Type: Grant
    Filed: October 7, 1987
    Date of Patent: June 20, 1989
    Assignee: Spring Valley Associates, Inc.
    Inventors: William W. Marshall, Lamar D. Springer
  • Patent number: 4817176
    Abstract: A method and apparatus for recognizing an unknown character, pattern, or indicia, or the like as being a particular one of a group of known reference characters, patterns, indicia, or the like. In the preferred embodiment, the system converts scanned and digitized MICR data and uses it to identify the character. The reference characters and the unknown character are Fourier Transformed and various corrections are made for eliminating the absolute amplitude difference from the recognition process, while simultaneously providing a method of correcting for position differences between the reference charcter and the unknown character. Provisions are made for weighting the phase differences proportional to the expected accuracy of the phase data to minimize the effects of noise on the measurement, and for combining the amplitude and phase data to define a single "best match" criteria for the unknown character.
    Type: Grant
    Filed: February 14, 1986
    Date of Patent: March 28, 1989
    Assignee: William F. McWhortor
    Inventors: William W. Marshall, William F. McWhortor
  • Patent number: 4424589
    Abstract: A flat bed scanner system for optically sensing a transparent original image and producing three channels of binary digital data representing the densities of the original image. Each channel produces data in response to one sensing color and sensing of the original image occurs by directing a focused image of a beam of white light onto and across the original image in a pattern of parallel scan lines there being a plurality of sensing positions along each scan line, and producing the digital output data in response to the modulated beam of light transmitted by the original image. There is an optical system which provides for the directing of the beam of white light across the original image and which directs the modulated beam onto sensors. The optical system includes color correction and field flattening of the beam of white light and provides a cylinder condenser lens for the modulated beam of white light.
    Type: Grant
    Filed: April 11, 1980
    Date of Patent: January 3, 1984
    Assignee: Coulter Systems Corporation
    Inventors: E. Raymond Thomas, Lysle D. Cahill, William W. Marshall, Luke L. Talley, John A. Lawson, Brian N. Wilcox