Patents Assigned to Research Development Company of Japan
  • Fluorescent substance and manufacturing method thereof
    Patent number: 5676882
    Abstract: A fluorescent substance of which main component is comprised from 32 mol % to 35 mol % of silicon element and from 68 mol % to 65 mol % of oxygen element, and in which includes from 10 ppm to 1 wt % of silicon carbide and silicon nitride as an activator. And, a manufacturing method of the fluorescent substance by hydrolyzing silicon alkoxide by using alkali or acid catalyzer under the presence of carbon, and by heat treating the obtained precursor at the temperature of 500.degree. C. to 900.degree. C.
    Type: Grant
    Filed: March 8, 1996
    Date of Patent: October 14, 1997
    Assignees: Toso Company, Ltd., Research Development Company of Japan
    Inventors: Nobusuke Yamada, Masahito Sano