Patents by Inventor John S. Palfreeman

John S. Palfreeman 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).

  • Magnetic bubble display systems
    Patent number: 4123783
    Abstract: A display arrangement including a source of polarized radiation; a magnetic material capable of supporting magnetic bubble domains in the path of the polarized beam, for producing a modulated beam; a device for representing an image encoded signal by means of the magnetic bubble domains; and a display device in the path of the modulated polarized beam for providing a visual display of the encoded image.
    Type: Grant
    Filed: March 8, 1976
    Date of Patent: October 31, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Ronald F. Pearson, David E. Lacklison, George B. Scott, John S. Palfreeman
  • Electrical filters including coupled resonators
    Patent number: 4065735
    Abstract: A surface acoustic wave band-pass filter comprising a piezoelectric substrate having on one surface first and second SAW resonators tuned to the same frequency and coupled together. An input transducer is coupled to the first resonator and an output transducer is coupled to the second resonator. Each resonator is preferably formed by two spaced apart aligned grating reflectors and the two resonators are preferably coupled by an array of discrete parallel metallic strips extending between the two cavity resonators.
    Type: Grant
    Filed: January 12, 1976
    Date of Patent: December 27, 1977
    Assignee: U.S. Philips Corporation
    Inventors: John S. Palfreeman, Martin Redwood, Frederick W. Smith, Richard F. Mitchell