Patents by Inventor Thomas D. G. Hellings

Thomas D. G. Hellings 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).

  • Infra-red sensitizing dyes for silver halide
    Patent number: 5041550
    Abstract: Infra-red sensitizing dyes for silver halide having a nucleus of the general formula: ##STR1## in which Q represents Cl or Br,R.sup.3 represents an alkyl or substituted alkyl,n is 0, 1, 2 or 3,X is an anion of molecular weight up to 400 which may be incorporated in one R.sup.3 group.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: August 20, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bernard A. Lea, Ronald W. Burrows, Thomas D. G. Hellings, Charles G. Barlow, Ivan H. Skoog
  • Infra-red sensitising dyes for silver halide
    Patent number: 4959294
    Abstract: Infra-red sensitizing dyes for silver halide having a mucleus of the general formula: ##STR1## in which: Q represents Cl or Br,R.sup.3 represents an alkyl or substituted alkyl,n is 0, 1, 2 or 3,X is an anion of molecular weight up to 400 which may be incorporated in one R.sup.3 group.
    Type: Grant
    Filed: April 14, 1988
    Date of Patent: September 25, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bernard A. Lea, Ronald W. Burrows, Thomas D. G. Hellings, Charles G. Barlow, Ivan H. Skoog
  • Photographic materials and color proofing system
    Patent number: 4818663
    Abstract: A radiation-sensitive element suitable for the preparation of half-tone color proofs comprising a substrate bearing at least four separate positive acting imaging media coated thereon, said imaging media including:(1) an imaging medium capable of forming a yellow image upon imagewise exposure and processing,(2) an imaging medium capable fo forming a magenta image upon imagewise exposure and processing,(3) an imaging medium capable of forming a cyan image upon imagewise exposure and processing, and(4) an imaging medium capable of forming a black image or a balancing black image upon imagewise exposure and processing,each imaging medium (1), (2) and (3) having a maximum spectral sensitivity at a wavelength different from that of the maxiumu sensitivity of the other imaging medium of (1) to (3), the imaging medium (4) having spectral sensitivity at each of the wavelengths of the maximum sensitivity of the other imaging media.
    Type: Grant
    Filed: April 2, 1987
    Date of Patent: April 4, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Stephen R. Powers, Thomas D. G. Hellings