Patents by Inventor Erhard Effer

Erhard Effer 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: 6171525
    Abstract: Disclosed is a process for the production of a photochromic object, composed of a polymer and containing at least one spirooxazin compound, having the following process steps: an acrylate monomer or a methacrylate monomer, respectively a mixture of a multiple thereof is utilized as the polymerizable monomer, the photochromic dyes as well as a polymerization initiator are mixed in the polymerizable monomer, the mixture yielded thereby is placed in a casting mold, polymerized and hardened. The present invention is distinguished by, in order to obtain a neutral gray, neutral brown or green photochromic tint of the polymerizable mixture, several photochromic dyes being added of which at least one is not a spirooxazin, and by the concentration of the spirooxazin compound(s) amounting to no more than 0.045 weight percent relative to the mass of the utilized monomer, and that of the polymerization initiator(s) amounting to more than 1 weight percent relative to the mass of the utilized monomer.
    Type: Grant
    Filed: January 12, 1998
    Date of Patent: January 9, 2001
    Assignee: Optische Werke G. Rodenstock
    Inventors: Erhard Effer, Manfred Melzig, Herbert Zinner, Herbert Schuster
  • Patent number: 5498686
    Abstract: An optically transparent photochromic plastic material is described which is comprised of materials with a sulphur content and which via polymerization processes contains photochromic organic compounds as solid ingredients, which possess at least two ring systems linked via carbon atom and whose photochromic tint is based on a reversible bond rupture to the spiro-C atom.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: March 12, 1996
    Assignee: Optische Werke G. Rodenstock
    Inventors: Erhard Effer, Manfred Melzig, Herbert Schuster, Guiseppe Martinuzzi
  • Patent number: 4852974
    Abstract: An anti-reflection film of several layers is described for an optical element consisting of an organic material with photochromic properties.The film according to the invention is characterized by the fact that the mean reflection of the film over the spectral range between 330 nm and 380 nm is less than 4% and the mean reflection over the range between 290 nm and 330 nm is greater than 15%. This reflection behavior serves to prevent the stimulation of the photochromic effect by light with too short a wavelength from reducing the useful life of the photochromic effect. In addition, a suitable choice of the reflection properties means that a deliberate stimulation of photochromic molecules situated in certain steric positions and so influence on the kinetics and color of the photochromic effect can be obtained.
    Type: Grant
    Filed: March 19, 1987
    Date of Patent: August 1, 1989
    Assignee: Optische Werke G. Rodenstock
    Inventors: Manfred Melzig, Erhard Effer