Patents Assigned to Patent-Treund-Gesellschaft F. Elektrische Gluehlampen mbH
  • Incandescent lamp
    Patent number: 6661164
    Abstract: The invention relates to an incandescent lamp whose lamp vessel (20) has an interference filter (30) with locally differing layer thickness for producing red light. The interference filter (30) has a second absorber layer and additional layers of low optical refraction and high optical refraction for reducing its transmission in the violet, blue and green spectral regions.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: December 9, 2003
    Assignee: Patent-Treund-Gesellschaft F. Elektrische Gluehlampen mbH
    Inventors: Juergen Ruemmelin, Reinhard Schaefer