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US 5,635,111 AGranted
Method of manufacturing a phosphor for use in an electroluminescent panel
AssigneeStanley Electric Co., Ltd.
InventorsKenichi Kawano, Mitsunori Harada, Takahiro Saida, Shuichi Taya, Shinichiro Seki, Kenichi Kondo
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Abstract
A phosphor for use in an electroluminescent panel is produced by firing a material primarily composed of powder of zinc sulfide, preferably with high-frequency induction heating, under a predetermined pressure in an atmosphere of a halogen gas as a coactivator. The phosphor thus produced is of good emission characteristics having minimum particle size and impurity concentration irregularities.
Claims3
A method of manufacturing phosphor, comprising the steps of:
- placing material comprising a mixture of zinc sulfide powder and copper sulfate powder into a heating vessel;
- placing the heating vessel into a fluid permeable storage body;
- placing the storage body into a reactor of an induction heating furnace;
- pressurizing nitrogen atmosphere of the reactor at a predetermined pressure, ranging from 10.sup.-3 Torr to 1140 Torr, when introducing the nitrogen gas;
- heating the mixed material at the predetermined pressure when introducing the nitrogen gas;
- introducing halogen gas into the reactor when reaching a predetermined temperature ranging from 550.degree. C. to 1200.degree. C.;
- and
- firing the mixture into an atmosphere of the nitrogen gas and the halogen gas as a coactivator, while keeping the interior of the reactor at the predetermined temperature and the predetermined pressure.
5 more elements
Dependencies are inferred from the claim text.