Patents Assigned to Gundula Roth
  • Patent number: 7828993
    Abstract: A phosphor for converting ultraviolet light or blue light emitted from a light emitting element into a visible white radiation having a high level of color rendering properties, containing a light emitting component prepared from a solid system of an alkaline earth metal antimonate and a system derived from the solid system and exhibiting intrinsic photoemission, such as a fluoroantimonate, a light emitting component prepared from a manganese(IV)-activated antimonate, a titanate, silicate-germanate, and an aluminate, a light emitting component prepared from a europium-activated silicate-germanate or from a system containing a sensitizer selected from a group consisting of europium (II) and manganese (II) as a secondary activator and having an orange color or a dark red color in the spectrum range over 600 nm, or a light emitting component composed of a mixture of eight or less light emitting components having different emission bands and brought to a state of continuous emission of about 380 to 780 nm exhibit
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: November 9, 2010
    Assignees: Tovoda Gosei Co.. Ltd., Gundula Roth, Walter Tews
    Inventors: Gundula Roth, Walter Tews
  • Patent number: 6085971
    Abstract: The present invention relates to variously activated luminescent metaborates having luminescence properties improved in comparison with conventional luminescent substances. Moreover, the activated luminescent metaborates have outstanding stability under the influence of short-wave UV radiation so that they are preferably suitable for use in luminescent screens, in particular, low-pressure mercury vapor discharge lamps of all types and designs. The luminescent substances of the present invention are based on rare earth metal borates of the formula:(Y,La).sub.1-x-y-z Ce.sub.x Gd.sub.y Tb.sub.2 (Mg,Zn,Cd).sub.1-p Mn.sub.p B.sub.5-q-s (Al,Ga).sub.q (X).sub.s O.sub.10wherein X is Si, Ge, P, Zr, V, Nb, Ta, W or the sum of a plurality of the stated elements and p, q, s, x, y and z are alternatively .ltoreq.1.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: July 11, 2000
    Assignees: Walter Tews, Gundula Roth
    Inventors: Walter Tews, Gundula Roth, Ina Fethke