Low pressure mercury vapor fluorescent lamps
AssigneeKoninklijke Philips Electronics N.V.
InventorsA. Gary Sigai, Snehasish S. Ghosh, David Curtis Nesting, Brett A. Carter
Life of this patent
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Abstract
A low mercury consumption electric lamp is provided having a a layer of a luminescent material comprising a phosphor derived from a mixture of a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns; a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns; and fines of a warm-white calcium halophosphate phosphor, preferably having an average particle size of about 4.62.
Claims19
An electric lamp which comprises:
- a lamp envelope having an inner surface;
- means within the lamp envelope for generating ultraviolet radiation;
- and
- a layer of a luminescent material on said inner surface comprising a phosphor derived from a mixture of
- (1) a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns;
- (2) a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns;
- and
- (3) fines of a warm-white calcium halophosphate phosphor.
A low pressure low-mercury consumption mercury vapor fluorescent lamp, comprising:
- a. a tubular, light transmissive lamp envelope having opposing sealed ends, an inner tubular surface and enclosing a discharge space between said sealed ends with a volume;
- b. a filling of elemental mercury and a rare gas;
- c. a pair of discharge electrodes each arranged at a respective sealed end of said lamp envelope;
- d. means for connecting said discharge electrodes to a source of electric potential outside of said lamp envelope, whereby during lamp operation a gas discharge is maintained between said discharge electrodes, which gas discharge emits ultraviolet radiation;
- e. optionally, a first, light transmissive and ultraviolet radiation reflecting layer disposed adjacent said inner surface of said lamp envelope,
- f. a layer of a luminescent material comprising a phosphor derived from a mixture of
- (1) a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns;
- (2) a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns;
- and
- (3) fines of a warm-white calcium halophosphate phosphor, said phosphor mixture providing a cool-white color to the lamp.
A low-mercury consumption mercury vapor fluorescent lamp, comprising:
- a. a tubular, light transmissive lamp envelope having opposing sealed ends, an inner tubular surface and enclosing a discharge space between said sealed ends with a volume;
- b. a filling of elemental mercury and a rare gas;
- c. a pair of discharge electrodes each arranged at a respective sealed end of said lamp envelope;
- d. means for connecting said discharge electrodes to a source of electric potential outside of said lamp envelope, whereby during lamp operation a gas discharge is maintained between said discharge electrodes, which gas discharge emits ultraviolet radiation;
- e. optionally, a first, light transmissive and ultraviolet radiation reflecting layer disposed adjacent said inner surface of said lamp envelope;
- f. a layer of a luminescent material comprising a phosphor derived from a mixture of
- (1) about 18% by weight of a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns;
- (2) about 41% by weight of a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns;
- and
- (3) about 41% by weight of fines of a warm-white calcium halophosphate phosphor,
- said phosphor mixture providing a cool-white color to the lamp.
A phosphor blend for low-mercury consumption fluorescent lamps which comprises:
- (1) a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns;
- (2) a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns;
- and
- (3) fines of a warm-white calcium halophosphate phosphor.
A phosphor blend for low-mercury consumption fluorescent lamps which comprises:
- (1) about 18% by weight of a blue-halo calcium halophosphate phosphor having an average particle size within the range of about 6.6 to about 10 microns;
- (2) about 41% by weight of a calcium-yellow calcium halophosphate phosphor having an average particle size within the range of about 9.0 to about 13 microns;
- and
- (3) about 41% by weight of fines of a warm-white calcium halophosphate phosphor, said phosphor mixture providing a cool-white color to the lamp.
Dependencies are inferred from the claim text.