Patents by Inventor Stephen P. Birkeland

Stephen P. Birkeland 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).

  • Film supply cassette for camera processor
    Patent number: 4455076
    Abstract: A film supply cassette comprising a hub, axially spaced end flanges, a trailer secured to the hub having an opening to cooperate with a sensor, a length of light-sensitive film convolutely wound about said trailer, and a leader comprising a vapor coated polyethylene/polyester laminate bonded to paper and wrapped about the film between the flanges and being wider than the film.
    Type: Grant
    Filed: September 13, 1982
    Date of Patent: June 19, 1984
    Assignee: Minnesota Mining & Manufacturing Company
    Inventor: Stephen P. Birkeland
  • Semiconductive and sensitized photoconductive compositions
    Patent number: 4222902
    Abstract: Semiconductive compositions are produced by the inclusion of a particular class of dyes into a polymeric binder. When the binder is an organic photoconductive binder, the dyes act as exceptionally good sensitizers for the photoconductive material.
    Type: Grant
    Filed: November 3, 1978
    Date of Patent: September 16, 1980
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: William A. Huffman, Stephen P. Birkeland, Kevin P. O'Leary
  • Semiconductive and sensitized photoconductive compositions
    Patent number: 4134764
    Abstract: Semiconductive compositions are produced by the inclusion of a particular class of dyes into a polymeric binder. When the binder is an organic photoconductive binder, the dyes act as exceptionally good sensitizers for the photoconductive material.
    Type: Grant
    Filed: November 19, 1976
    Date of Patent: January 16, 1979
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: William A. Huffman, Stephen P. Birkeland, Kevin P. O'Leary
  • Semiconductive and sensitized photoconductive compositions
    Patent number: 4052209
    Abstract: Semiconductive compositions are produced by the inclusion of a particular class of dyes into a polymeric binder. When the binder is an organic photoconductive binder, the dyes act as exceptionally good sensitizers for the photoconductive material.
    Type: Grant
    Filed: March 7, 1975
    Date of Patent: October 4, 1977
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: William A. Huffman, Stephen P. Birkeland, Kevin P. O'Leary
  • Chemical container
    Patent number: D271113
    Type: Grant
    Filed: July 9, 1981
    Date of Patent: October 25, 1983
    Assignee: Minnesota Mining & Manufacturing Company
    Inventors: Stephen P. Birkeland, Noboru Sawamura