Patents Assigned to Kabushiki Kaisha Tokyo Kagaku Kenkyusho
  • Phosphor with afterglow characteristic
    Patent number: 5770111
    Abstract: A phosphor exhibiting afterglow more intensely and persistently than (Sr, Eu, Dy)O.Al.sub.2 O.sub.3 phosphors. The phoshor has a chemical composition comprising mainly an Eu.sup.2+ activated strontium aluminate phosphor substance as a matrix in which a part of the strontium (Sr) is substituted with at least one of Pb, Dy and Zn.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: June 23, 1998
    Assignee: Kabushiki Kaisha Tokyo Kagaku Kenkyusho
    Inventors: Hirofumi Moriyama, Tomofumi Moriyama, Teruo Goto