Patents by Inventor Herbert Mitzinger

Herbert Mitzinger 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: 5869224
    Abstract: In reversal processing, washing between the first development and the reversal bath can be avoided without any loss of photographic quality if the reversal bath is operated in countercurrent over at least two stages and hydroquinone sulfonic acid is used as the first developer.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: February 9, 1999
    Assignee: Agfa Gevaert Aktiengesellschaft
    Inventor: Herbert Mitzinger
  • Patent number: 5858631
    Abstract: The processing of exposed colour photographic materials by at least the steps of colour developing and bleach-fixing, with electrolytic desilvering of the spent bleach fixative solution, results in better utilisation of the processing chemicals and in a reduced amount of liquid to be disposed of, when bleach-fixing is effected in 2 steps, wherein a pH of .gtoreq.7.4 is set in the 1st step and a pH of .ltoreq.7 is set in the 2nd step, the bleach fixative from the 1st step is electrolytically desilvered and acid for maintaining the pH is fed to the 2nd step.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: January 12, 1999
    Assignee: Agfa Gevaert Aktiengesellschaft
    Inventors: Udo Quilitzsch, Herbert Mitzinger
  • Patent number: 5135841
    Abstract: Colored copies of outstanding quality are obtained from half tone originals by means of a color paper of extremely hard gradation if the silver halide emulsions of the color paper consists substantially of silver chloride and if, before the material is processed, a filtered, homogeneous exposure is carried out, extending from sub-threshold pre-exposure to an exposure which reduces the maximum color densities by 0.4 density units.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: August 4, 1992
    Assignee: Agfa Gevaert Aktiengesellschaft
    Inventors: Ubbo Wernicke, Herbert Mitzinger, Udo Quilitzsch
  • Patent number: 5006439
    Abstract: A photographic reversal process for the production of positive photographic images by imagewise exposure of the photosensitive material containing at least one silver halide emulsion layer, black-and-white first development of the material, chemical fogging, color development and bleaching, fixing, washing or stabilizing and drying, in which the material is transferred from the first development to the color development without any intermediate steps, such as intermediate washing or diffuse second exposure, the first development bath exclusively contains one or more N,N-dialkyl-p-phenylenediamine derivatives as developer and a tin(II) complex compound and is adjusted to a pH value of <8 and the color development bath likewise exclusively contains one or more N,N-dialkyl-p-phenylenediamine derivatives as developer and is adjusted to a pH value >10, requires considerably less time than the conventional process but produces equivalent results.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: April 9, 1991
    Assignee: Agfa-Gevaert Aktiengesellschaft
    Inventors: Ubbo Wernicke, Herbert Mitzinger
  • Patent number: 4997749
    Abstract: True-to-type development without any overflow is achieved with a developer solution system of a refill solution and--replenished therewith--a ready-to-use developer solution which contains the following constituents in the quantities indicated per liter aqueous solution and, optionally, other typical consituents:3-15 g of the following color developer compound ##STR1## or a corresponding quantity of salts thereof, 8-35 g PO.sub.4.sup.3 ions,at least 0.2 g antioxidant and2.1-4.2 g KBrand which is adjusted to a pH value of 10.5 to 12.5, the regeneration quota amounting to between 50 and 120 ml/m.sup.2 developed material and the refill solution containing the individual constituents in a such a concentration that, for the above-mentioned regeneration quota, the in-use developer solution always contains the constituents shown above in the quantities indicated.
    Type: Grant
    Filed: December 27, 1988
    Date of Patent: March 5, 1991
    Assignee: Agfa-Gevaert Aktiengesellschaft
    Inventors: Ubbo Wernicke, Herbert Mitzinger