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Title:
FLUORESCENT LAMP
Document Type and Number:
Japanese Patent JPS61135042
Kind Code:
A
Abstract:

PURPOSE: To prevent any discoloration of a fluorescent lamp resulting from its prolonged lighting by coating the inner surface of a glass bulb with a fluorescent layer prepared from a mixture of a rare earth phosphor and β type calcium pyrophosphate having a particle size similar to that of the rare earth phosphor.

CONSTITUTION: First, strontium calcium chlorophosphate phosphor activated with europium, lanthanum phosphate phosphor activated with cerium and terbium and yttrium oxide phosphor activated with europium are mixed in a ratio of 2 to 4 to 4 to prepare a rear earth phosphor. Next, 100pts.wt. of the rare earth phosphor is mixed with 10W60pts.wt. of β type calcium pyrophosphate having a particle size similar to that of the rare earth phosphor. After that, the thus prepared mixture is applied to the inner surface of a glass bulb to form a fluorescent layer, thereby making a fluorescent lamp. The use of calcium pyrophosphate with β type crystalline structure prevents any undesirable discoloration from developing even when the lamp is lit over a long time. Besides, it is possible to achieve improved efficiency of applying the fluorescent layer.


Inventors:
URATA YOSHIZO
OSONO TORU
Application Number:
JP25809884A
Publication Date:
June 23, 1986
Filing Date:
December 05, 1984
Export Citation:
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Assignee:
NIPPON DENKI HOME ELECTRONICS
International Classes:
C09K11/02; H01J61/46; (IPC1-7): H01J61/46
Domestic Patent References:
JPS58218745A1983-12-20
JPS5289282A1977-07-26
JPS543160A1979-01-11