Patents by Inventor Oh Junrok

Oh Junrok 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).

  • Patent number: 6423247
    Abstract: A light-storing fluorescent pigment comprising a mother crystal and a rare earth element with which said mother crystal is doped, characterized in that said light-storing fluorescent pigment is produced by calcining a gel powder, as a starting material, obtained from an arbitrary combination of an alkoxide derivative, an organic acid salt, an inorganic acid salt, an oxide and a chloride of metal elements constituting said pigment by using a sol-gel method. A simplified production process can be used and the resulting light-storing fluorescent pigment has high crystal purity, is free from contamination with impurities and it is possible to easily control the particle diameter of the pigment.
    Type: Grant
    Filed: July 16, 1999
    Date of Patent: July 23, 2002
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Mizue Fukushima, Hiroshi Hirashima, Hiroaki Imai, Oh Junrok