US 7,601,277 B2
	Fluorescent substance and light-emitting device using the same
Naomi Shida, Tokyo (Japan); Masaaki Tamatani, Fujisawa (Japan); Yoshihito Tsutsui, Chigasaki (Japan); Kazuaki Ootsuka, Yokosuka (Japan); and Ryosuke Hiramatsu, Kawasaki (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan); and Toshiba Materials Co., Ltd., Kanagawa (Japan)
Filed on Jan. 31, 2008, as Appl. No. 12/23,677.
Application 12/023677 is a continuation of application No. 11/249946, filed on Oct. 13, 2005, granted, now 7,468,147.
Claims priority of application No. 2004-303509 (JP), filed on Oct. 18, 2004.
Prior Publication US 2008/0283797 A1, Nov. 20, 2008
This patent is subject to a terminal disclaimer.
Int. Cl. C09K 11/55 (2006.01); C09K 11/59 (2006.01)

U.S. Cl. 252—301.4F  [428/404; 428/403; 428/405; 428/406; 428/407; 257/98; 313/503]

19 Claims

1. A fluorescent substance comprising an alkaline earth ortho-silicate, the fluorescent substance being a particle activated by Eu2+ and comprising at least one selected from the group consisting of La, Gd, Cs and K, the particle having a surface covering material on a surface.