Patents by Inventor Ehrhard Hellmig

Ehrhard Hellmig 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).

  • Color correction of unwanted side densities in light-sensitive color photographic elements
    Patent number: 4036646
    Abstract: A color photographic material having three light-sensitive silver halide emulsion layers separately sensitized to different regions of the spectrum and containing an each colorless coupler for the production of partial color images, is partly fogged in one of said layers to produce on color development in unexposed areas a color fog with a density of between 0.25 and 0.75 suited to compensate for undesired side densities of the image dye in one or more of the other of said layers.
    Type: Grant
    Filed: March 4, 1975
    Date of Patent: July 19, 1977
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Ehrhard Hellmig, Erwin Ranz
  • Light-sensitive color photographic material with masking layer comprising spontaneously silver halide
    Patent number: 4023970
    Abstract: A light-sensitive color photographic material comprises four silver halide emulsion layer units, one for recording each of the yellow, magenta and cyan partial images and one which serves as a color correction layer. The latter mentioned silver halide emulsion layer is fogged, has a lower light-sensitivity than the light-sensitive partial image recording layer, and contains color couplers for producing a yellow to magenta masking image to compensate for the undesired side densities in at least two image recording layers.
    Type: Grant
    Filed: April 28, 1975
    Date of Patent: May 17, 1977
    Assignee: AGFA-Gevaert, A.G.
    Inventors: Ehrhard Hellmig, Erwin Ranz
  • Process for the production of negative continuous-tone images
    Patent number: 3977872
    Abstract: Negative continuous-tone images or continuous-tone separation records having standardized contrast are produced from originals which are differing in contrast by means of a photograhic material the silver halide emulsion of which has a characteristic curve with a sagging course defined below, whereby the part of characteristic curve which is utilized for the production of the continuous-tone negative depends on the contrast of the original.
    Type: Grant
    Filed: July 7, 1975
    Date of Patent: August 31, 1976
    Assignee: AGFA-Gevaert, A.G.
    Inventor: Ehrhard Hellmig