Patents by Inventor Bernard A. Lea

Bernard A. Lea 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: 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
  • 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
  • Patent number: 4857450
    Abstract: High contrast negative acting silver halide emulsions suitable for laser scanning applications comprising a Group VIII metal compound and one or more spectrally sensitizing dyes of the formula ##STR1## The emulsions have good long term stability and good sensitivity.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: August 15, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ronald W. Burrows, Keith A. Penfound, Bernard A. Lea
  • Patent number: 4835096
    Abstract: Photothermographic elements of the dry silver type may be sensitized to the infrared with sensitizing dyes of the formula: ##STR1## in which: R.sup.1 represents a lower alkyl group of from 1 to 5 carbon atoms andX.sup.- represents an anion.
    Type: Grant
    Filed: April 2, 1987
    Date of Patent: May 30, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Bernard A. Lea
  • Patent number: 4594312
    Abstract: Photothermographic elements containing heat bleachable acutance/antihalation dyes and thermographic elements employing heat bleachable dyes of the formula: ##STR1## in which: n is 2, 3, 4 or 5,at least one of R.sup.1 to R.sup.4 represent hydrogen and the remainder of R.sup.1 to R.sup.4 independently represent a hydrogen atom, an optionally substituted cycloalkyl group, an optionally substituted alkenyl group, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heterocyclic aromatic group, or R.sup.1 and R.sup.2 together or R.sup.3 and R.sup.4 together represent the necessary atoms selected from C, N, O and S to complete a non-aromatic type ring,X.sup..crclbar. is an anion.
    Type: Grant
    Filed: March 6, 1984
    Date of Patent: June 10, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Gebran J. Sabongi, Stephen S. C. Poon, Bernard A. Lea
  • Patent number: 4581325
    Abstract: A photographic element of the conventional wet processed type or of the dry silver type which includes an antihalation or acutance dye which absorbs in the near infrared and has a relatively low visible absorption while retaining a high extinction coefficient at .sub.max. The dye is of the general formula: ##STR1## in which: m+p=2,n is 0 or 1,s is 0 or 1,Z.sup.1 and Z.sup.2 independently represent the non-metallic atoms necessary to complete a heterocyclic nucleus of the type present in cyanine dyes,R.sup.1 and R.sup.2 independently represent an alkyl or substituted alkyl, alkenyl, substituted alkenyl or aralkyl group of up to 20 carbon atoms,R.sup.3 and R.sup.4 independently represent a hydrogen atom or an alkyl, substituted alkyl, alkenyl or substituted alkenyl group of up to 10 carbon atoms,R.sup.5, R.sup.6, R.sup.7 and R.sup.
    Type: Grant
    Filed: January 23, 1985
    Date of Patent: April 8, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jonathan P. Kitchin, Bernard A. Lea, Ronald W. Burrows
  • Patent number: 4283487
    Abstract: Images produced in photothermographic emulsions using silver halide as a light-sensitive material therein suffer from light scattering effects on the silver halide.Acutance dyes, many of which are novel, are disclosed which can absorb scattered light and which are bleached at the development temperature of the photothermographic composition.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: August 11, 1981
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Bernard A. Lea, Ronald W. Burrows
  • Patent number: 4153463
    Abstract: Magenta acutance dyes for photothermographic emulsions are disclosed.
    Type: Grant
    Filed: April 14, 1978
    Date of Patent: May 8, 1979
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Bernard A. Lea