Patents by Inventor Karl H. Drexhage

Karl H. Drexhage 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: 4524204
    Abstract: A process for replacing and recovering the anion of an acid-stable organic cationic salt comprises the steps of:(a) preparing a first dispersion or solution by combining(i) a first acid-stable, organic cationic salt having an anion,(ii) a water-immiscible organic solvent, and(iii) the acid of a solubilizing anion, thereby forming (1) a second organic cationic salt having said solubilizing anion, and (2) an acid of said anion of said first organic cationic salt, and (3) an excess, if any, of an acid of said solubilizing anion, said second organic cationic salt having a solubility in 2-ethoxyethanol:2-methoxyethyl acetate (1:1 by weight) at least 5 percent greater than said first organic cationic salt;(b) removing the acid formed in said first dispersion or solution by, at least once(i) mixing water with said first dispersion or solution to form a mixture comprising (1) said first dispersion or solution, and (2) a second solution comprising water, at least a portion of the acid formed in said first solution, an
    Type: Grant
    Filed: August 4, 1980
    Date of Patent: June 18, 1985
    Assignee: Eastman Kodak Company
    Inventor: Karl H. Drexhage
  • Patent number: 4416961
    Abstract: Color filter arrays for color imaging devices are disclosed. The arrays are formed in a single layer of a transparent binder containing at least one cationic photo-bleachable dye. The layer has a thickness less than 10 microns, and the dye is present in the layer in an amount sufficient to impart a density to the layer of at least about 0.5 in that portion of the spectrum in which it selectivity absorbs. A method of making the arrays is also disclosed which includes the steps of (1) forming a layer of a transparent binder containing the photo-bleachable dye or dyes and a sensitizer; (2) exposing the layer to a pattern which represents a set of filter elements so as to photo-bleach the photo-bleachable dye; and (3) fixing the layer by leaching the sensitizer from the layer. In particularly preferred embodiments, the dyes are chosen so that those which absorb at longer wavelengths have a lower bleaching efficiency than those which absorb at shorter wavelengths.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: November 22, 1983
    Assignee: Eastman Kodak Company
    Inventor: Karl H. Drexhage
  • Patent number: 4345011
    Abstract: Color filter arrays for color imaging devices are disclosed. The arrays are formed in a single layer of a transparent binder containing at least one cationic photo-bleachable dye. The layer has a thickness less than 10 microns, and the dye is present in the layer in an amount sufficient to impart a density to the layer of at least about 0.5 in that portion of the spectrum in which it selectively absorbs. A method of making the arrays is also disclosed which includes the steps of (1) forming a layer of a transparent binder containing the photo-bleachable dye or dyes and a sensitizer; (2) exposing the layer to a pattern which represents a set of filter elements so as to photo-bleach the photo-bleachable dye; and (3) fixing the layer by leaching the sensitizer from the layer. In particularly preferred embodiments, the dyes are chosen so that those which absorb at longer wavelengths have a lower bleaching efficiency than those which absorb at shorter wavelengths.
    Type: Grant
    Filed: September 11, 1980
    Date of Patent: August 17, 1982
    Assignee: Eastman Kodak Company
    Inventor: Karl H. Drexhage
  • Patent number: 4247799
    Abstract: Color filter arrays for color imaging devices are disclosed. The arrays are formed in a single layer of a transparent binder containing at least one cationic photo-bleachable dye. The layer has a thickness less than 10 microns, and the dye is present in the layer in an amount sufficient to impart a density to the layer of at least about 0.5 in that portion of the spectrum in which it selectively absorbs. A method of making the arrays is also disclosed which includes the steps of (1) forming a layer of a transparent binder containing the photo-bleachable dye or dyes and a sensitizer; (2) exposing the layer to a pattern which represents a set of filter elements so as to photo-bleach the photo-bleachable dye; and (3) fixing the layer by leaching the sensitizer from the layer. In particularly preferred embodiments, the dyes are chosen so that those which absorb at longer wavelengths have a lower bleaching efficiency than those which absorb at shorter wavelengths.
    Type: Grant
    Filed: January 30, 1978
    Date of Patent: January 27, 1981
    Assignee: Eastman Kodak Company
    Inventor: Karl H. Drexhage
  • Patent number: 4212519
    Abstract: Light-control devices of the type having field-orientable, light-control elements supported in a solid elastomeric matrix are constructed in a manner providing improved uniformity in light-control and, in image display uses, improved resolution and contrast. Features of the improved construction include predetermined physical characteristics such as size, shape and/or location of the light-control elements within the matrix. Various methods for achieving such constructions include the steps of forming the desired array of elements and disposing the array in the matrix with relative positions of the elements maintained.
    Type: Grant
    Filed: March 1, 1978
    Date of Patent: July 15, 1980
    Assignee: Eastman Kodak Company
    Inventors: Karl H. Drexhage, Joseph J. Wrobel