Patents by Inventor Kotaro Koomoto

Kotaro Koomoto 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).

  • Fluorescent lamp containing a green emitting rare earth silicate coactivated phosphor
    Patent number: 4208611
    Abstract: A rare earth silicate phosphor co-activated by cerium and terbium which is expressed by the general structural formula:Ln.sub.2(1-x-y) O.sub.3.zSiO.sub.2 :Ce.sub.2x.Tb.sub.2ywhere:Ln is at least one rare earth element selected from the group consisting of yttrium, lanthanum, gadolinium and lutetium,x is 1.times.10.sup.-3 to 3.times.10.sup.-1 gram atom per gram atom of all the rare earth elements,y is 3.times.10.sup.-2 to 3.times.10.sup.-1 gram atom per gram atom of all the rare earth elements,z is 0.8 to 2.2 mol per mol of rare earth oxide,and the phosphor efficiently emits green rays when excited by ultraviolet rays.
    Type: Grant
    Filed: April 12, 1978
    Date of Patent: June 17, 1980
    Assignee: Tokyo Shibaura Electric Co., Ltd.
    Inventors: Minoru Watanabe, Toshio Nishimura, Tadao Omi, Kotaro Koomoto, Tomohiko Kobuya, Kenichi Shimizu