Patents by Inventor John D. Hakanson

John D. Hakanson 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).

  • Static reduction in magnetic record disk assemblies
    Patent number: 4722017
    Abstract: Triboelectric charging of magnetic record disk jackets causes static electricity to attract and hold foreign matter. This triboelectric charging can be reduced by the application of nonvolatile, non-integral, electrically conductive organic coatings on the surfaces of the jackets.
    Type: Grant
    Filed: January 9, 1986
    Date of Patent: January 26, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Wayne H. Vannet, John D. Hakanson, Gerald J. Niles
  • Static reduction in magnetic recording cassettes
    Patent number: 4570197
    Abstract: The provision of non-volatile, electrically conductive organic coatings to the surfaces of cassettes housing magnetic recording tape substantially reduces triboelectric charging.
    Type: Grant
    Filed: January 3, 1983
    Date of Patent: February 11, 1986
    Assignee: Minnesota Mining & Manufacturing Company
    Inventors: John D. Hakanson, Gerald J. Niles
  • Magnetic head cleaning tape and method
    Patent number: 3978520
    Abstract: Magnetic heads of color video tape recorder (vtr) machines are cleaned without harmful abrasion by means of a novel magnetic head cleaning tape carrying a color bar signal. Abrupt appearance of the color bar test pattern at the video monitor permits cessation of the cleaning operation immediately upon complete removal of foreign matter and without harmful abrasion of the heads.
    Type: Grant
    Filed: November 29, 1974
    Date of Patent: August 31, 1976
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: John V. Nowicki, John D. Hakanson