Patents by Inventor Qingfen Hao

Qingfen Hao 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).

  • Long decay luminescent material
    Patent number: 5853614
    Abstract: Long decay luminescent materials having improved long decay time and improved high brightness is represented by the formula asSr.sub.0.9995 .about..sub.0.998 Eu.sub.0.0005 .about..sub.0.002)Al.sub.2 O.sub.4 .multidot.(Sr.sub.0.9995 .about..sub.0.998 Eu.sub.0.0005 .about..sub.0.002)O .multidot.n(Al.sub.1-a-b B.sub.b Dy.sub.a).sub.2 O.sub.3in it a=0.0005.about.0.0002, b=0.0001.about.0.35, n=1.about.8 and the method for manufacturing the long decay luminescent materials is characterized in heating the raw materials as SrCo.sub.3, .alpha. type alumina, .gamma. type alumina, boron-containing compound, Eu.sub.2 O.sub.3 and Dy.sub.2 O.sub.3 gradually from 400.degree. C. up to 1250.degree. C..about.1600.degree. C. during 7.about.10 hours, firing it at 1250.degree. C..about.1600.degree. C. for 3.about.5 hours and then cooing it gradually from 1250.degree. C..about.1600.degree. C. down to 200.degree. C. during 7.about.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: December 29, 1998
    Assignees: Beijing Hongye Coating Materials Company, Chemitech, Inc.
    Inventors: Qinglong Hao, Qian Xu, Jun Li, Pengcheng Li, Baochan Liu, Atsushi Ogura, Qingfen Hao