CA1065949A - Fluorescent lamp construction utilizing a mixture of two phospor materials - Google Patents
Fluorescent lamp construction utilizing a mixture of two phospor materialsInfo
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- CA1065949A CA1065949A CA262,312A CA262312A CA1065949A CA 1065949 A CA1065949 A CA 1065949A CA 262312 A CA262312 A CA 262312A CA 1065949 A CA1065949 A CA 1065949A
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Abstract
ABSTRACT OF THE DISCLOSURE
A fluorescent lamp construction uses a particular blended phosphor mixture to provide an efficient light source having good color rendition. The phosphor mixture uses a blend of a strontium-haloapatite phosphor with europium-activated yttrium oxide phosphor. The phosphor mixture produces light emission in a color temperature range from about 2,700°K to about 6,500°K with both a satisfactory color rendition and higher luminous efficiency than can be obtained with conventional phosphor mixtures.
The useful strontium-haloapatite phosphors include strontium blue halophosphate phosphor activated with antimony, strontium green halophosphate phosphor coactivated with antimony and man-ganese, and strontium yellow halophosphate phosphor which contains a still greater manganese activator level. The useful strontium-haloapatite phosphor have the general formula: Sr10-x-ySbxMny(PO4)6.A2 wherein A is a halide selected from F and C1 including combinations thereof, x is in the approximate range 0.04 to 0.15, and y is in the approximate range 0.01 to 0.42. The phosphor mixture contains approximately 75 to 85 weight percent of the strontium-haloapatite phosphor.
A fluorescent lamp construction uses a particular blended phosphor mixture to provide an efficient light source having good color rendition. The phosphor mixture uses a blend of a strontium-haloapatite phosphor with europium-activated yttrium oxide phosphor. The phosphor mixture produces light emission in a color temperature range from about 2,700°K to about 6,500°K with both a satisfactory color rendition and higher luminous efficiency than can be obtained with conventional phosphor mixtures.
The useful strontium-haloapatite phosphors include strontium blue halophosphate phosphor activated with antimony, strontium green halophosphate phosphor coactivated with antimony and man-ganese, and strontium yellow halophosphate phosphor which contains a still greater manganese activator level. The useful strontium-haloapatite phosphor have the general formula: Sr10-x-ySbxMny(PO4)6.A2 wherein A is a halide selected from F and C1 including combinations thereof, x is in the approximate range 0.04 to 0.15, and y is in the approximate range 0.01 to 0.42. The phosphor mixture contains approximately 75 to 85 weight percent of the strontium-haloapatite phosphor.
Description
~065~49 This invention relates generally to a low-pressure mercury vapor discharge lamp having a par-ticular type phosphor coating to emit white light when excited by the ultraviolet radiation generated from the mercury vapor discharge. More particularly, the present type lamp construction is intended for general illumination at a color temperature in the range
2,700 K - 6,500 K with a satisfactory color rendition and at higher emission e~ficiency than conventional deluxe-type fluorescent lamps.
The use of several luminescent materials in combination to produce a predetermined overall spectral energy distribution is well-known. It is also well-known to employ such material combinations as a blended mixture or as a plurality of two or more layers in which one layer generally further comprises a blend of the individual phosphors. Particularly well-known phosphor blends in the form of a single layer phosphor coating to produce white color emission include two component mixtures for deluxe cool-white and deluxe warm-white. These already well-known two component phosphor mixtures generally employ a manganese-activated or antimony-activated strontium haloapatite phosphor constituent including various combinations thereof. Conventiona] deluxe-type fluore-scent lamps represent a compromise between luminous efficiency (lumen output per watt input) and color rendition since better color rendition is usually achieved with a reduction of as much as 35 percent or more in luminous efficiency. A ~atisfactory color rendition for deluxe-type fluorescent lamps is approximately 80 or more as measured by the generally ~065949 accepted C.I.E. color rendering index. The color temperature of the emission in these lamps is also fixed at around 3,000K for the warm-white deluxe lamp, around 3,500K for the standard white deluxe lamp, around 4,200K for the cool-white deluxe lamp, and around 6,500K for the daylight deluxe lamp, as measured by the C.I.E. chromaticity x and y values.
A relatively recent fluorescent lamp de-velopment employs various rare earth oxide phosphorsexhibiting higher luminou# efficiency than the conventional phosphors to increase the overall eff-iciency of the phosphor combination. A rare earth oxide phosphor being employed in this manner is generally blended with two or more different phosphor materials to provide efficient composite emission.
In a different known embodiment, the relatively ex-pensive rare earth oxide phosphor material is employed as a separate top layer overlying a phosphor blend layer of less expensive phosphor~ to increase the absorption of ultraviolet radiation by the expensive material and thereby increa~e the composite emission.
Such a combination permits accomplishment of a predetermined spectral energy distribution utilizing le~s rare earth oxide phosphor material than would be the case if a single phosphor layer of the blended mixture were employed.
The present invention provides a particular combination of two different phosphor materials to achieve improved luminous efficiency at comparable color rendition in a deluxe-type fluorescent lamp.
More particularly, it has been found that a comb-~065~49 ination of a strontiumhaloapatite phosphor with europium-activated yttrium oxide phosphor produces the desired emission at a color temperature range from about 2,700K to about 6,500K with both a satis-factory color rendition and higher luminous efficiency than can be obtained with conventional phosphor blends. The particular strontiumhaloapatite phosphors which can be used in this manner are already well-known and the general class of such phosphor materials is described in U.S. Patent 2,488,733 to McKeag and Ranby dated November 22, 1969. The useful stron-tiumhaloapatite phosphors comprise strontium blue halophosphate phosphor utilizing antimony activated, strontium green halophosphate phosphor coactivated with antimony and manganese, and strontium yellow halophosphate phosphor which contains a still greater manganese activator level. The useful class of these phosphor materials can be represented by the following formula: Sr10_x_ySbxMny ( 4)6 2 in A is a halide ion selected from F and Cl including combinations thereof, x can be in the range from approximately 0.04-0.15 and y can range from approx-imatel~ 0.01-0.42. These phosphor materials can be prepared in conventional fashion by firing a mixture of SrH P04, SrC03, SrF2, MnCO3, and Sb203 from four to six hours at 1,100 C.
Useful europium-activated yttrium oxide phosphors in the practice of the present invention are also well-known as disclosed in the U.S. Patent
The use of several luminescent materials in combination to produce a predetermined overall spectral energy distribution is well-known. It is also well-known to employ such material combinations as a blended mixture or as a plurality of two or more layers in which one layer generally further comprises a blend of the individual phosphors. Particularly well-known phosphor blends in the form of a single layer phosphor coating to produce white color emission include two component mixtures for deluxe cool-white and deluxe warm-white. These already well-known two component phosphor mixtures generally employ a manganese-activated or antimony-activated strontium haloapatite phosphor constituent including various combinations thereof. Conventiona] deluxe-type fluore-scent lamps represent a compromise between luminous efficiency (lumen output per watt input) and color rendition since better color rendition is usually achieved with a reduction of as much as 35 percent or more in luminous efficiency. A ~atisfactory color rendition for deluxe-type fluorescent lamps is approximately 80 or more as measured by the generally ~065949 accepted C.I.E. color rendering index. The color temperature of the emission in these lamps is also fixed at around 3,000K for the warm-white deluxe lamp, around 3,500K for the standard white deluxe lamp, around 4,200K for the cool-white deluxe lamp, and around 6,500K for the daylight deluxe lamp, as measured by the C.I.E. chromaticity x and y values.
A relatively recent fluorescent lamp de-velopment employs various rare earth oxide phosphorsexhibiting higher luminou# efficiency than the conventional phosphors to increase the overall eff-iciency of the phosphor combination. A rare earth oxide phosphor being employed in this manner is generally blended with two or more different phosphor materials to provide efficient composite emission.
In a different known embodiment, the relatively ex-pensive rare earth oxide phosphor material is employed as a separate top layer overlying a phosphor blend layer of less expensive phosphor~ to increase the absorption of ultraviolet radiation by the expensive material and thereby increa~e the composite emission.
Such a combination permits accomplishment of a predetermined spectral energy distribution utilizing le~s rare earth oxide phosphor material than would be the case if a single phosphor layer of the blended mixture were employed.
The present invention provides a particular combination of two different phosphor materials to achieve improved luminous efficiency at comparable color rendition in a deluxe-type fluorescent lamp.
More particularly, it has been found that a comb-~065~49 ination of a strontiumhaloapatite phosphor with europium-activated yttrium oxide phosphor produces the desired emission at a color temperature range from about 2,700K to about 6,500K with both a satis-factory color rendition and higher luminous efficiency than can be obtained with conventional phosphor blends. The particular strontiumhaloapatite phosphors which can be used in this manner are already well-known and the general class of such phosphor materials is described in U.S. Patent 2,488,733 to McKeag and Ranby dated November 22, 1969. The useful stron-tiumhaloapatite phosphors comprise strontium blue halophosphate phosphor utilizing antimony activated, strontium green halophosphate phosphor coactivated with antimony and manganese, and strontium yellow halophosphate phosphor which contains a still greater manganese activator level. The useful class of these phosphor materials can be represented by the following formula: Sr10_x_ySbxMny ( 4)6 2 in A is a halide ion selected from F and Cl including combinations thereof, x can be in the range from approximately 0.04-0.15 and y can range from approx-imatel~ 0.01-0.42. These phosphor materials can be prepared in conventional fashion by firing a mixture of SrH P04, SrC03, SrF2, MnCO3, and Sb203 from four to six hours at 1,100 C.
Useful europium-activated yttrium oxide phosphors in the practice of the present invention are also well-known as disclosed in the U.S. Patent
3,301,791 to Brixner dated ~anuary 31, 1967. As will be further described in connection with the following preferred embodiments, the selection of ~065949 particular phosphor material constituents and the proportion of these phosphor constituents in a blended mixture i8 accomplished in a specific manner from the predetermined visible spectral energy dis-tribution desired as measured by the C.I.E.
chromaticity values.
Embodiments of the invention will now be described with references to the accompanying drawings in which:
FIG~ l is a perspective view partially broken away of a fluorescent lamp construction in accordance with the present invention;
FIG. 2 i~ a vi~ible emission curve for a blended phosphor mixture in accordance with the present invention7 and FIG. 3 is a C.I.E. chromaticity diagram including the black body locus line with corresponding color temperatures indicated thereon for various deluxe-type fluorescent lamp~.
The particular phosphor combination herein employed utilizes one phosphor constituent emitting relatively broad band emissions in the lower spectral region from approximately 4,500 Angstroms to 5,900 Angstroms along with a specific rare earth oxide phosphor constituent exhibiting narrow band emission in the spectral energy region from approximately 6,000 Angstroms to about 6,150 Angstroms for higher emission efficiency and satisfactory color rendition at the desired color temperature. By varying the weight ratio of these phosphor constituents in the blended mixture as hereinafter described in greater detail, it becomes possible to achieve the same 1065~49 approximate color temperature that is emitted by conventional deluxe-type fluorescent lamps. The im-provement in composite emission results from the relatively higher emission efficiency of the rare earth oxide phosphor compared with that for the tin-activated orthophosphate phosphor now used in said conventional lamps and the present phosphor combination has also been found to provide this benefit, with no appreciable decrease in lamp maintenance.
Referring to FIG. l, there is shown a fluorescent lamp l comprising an elongated soda-lime silicate glass bulb 2 with a circular cross section.
The discharge assembly in said lamp has the usual electrode structure 3 at each end supported by in-lead wires 4 and 5 which extend through a glass press seal 6 in a mount stem 7 to the contacts of a base 8 affixed at opposite ends of the lamp. The dis-charge-sustaining filling in the sealed glass tube is an inert gas such as argon or a mixture of argon and other gases at a low pressure in combination with a small quantity of mercury to provide the low vapor pressure manner of lamp operation. The inner surface of the glass bulb iB provided with a phosphor coating 9 which is applied extending substantially the full length of the bulb and around the bulb circumferential inner wall.
To better illustrate the improvement obtained in emission behavior for the above type lamp construction utilizing the present phosphor combination as a blended mixture, various -40-WT12 lamps were constructed for comparison with conventional deluxe-type fluorescent lamps now utilizing strontium blue ~L065~49 halophosphate or strontium green halophosphate with tin-activated strontium orthophosphate in approximately equal weight proportions. The conventional deluxe white lamps exhibited approximately 2,100 lumens value at 100 hours with a color temperature within the color oval shown in FIG. 3 while the present phosphor combination utilizing an approximate 80 parts strontium green halophosphate with 20 parts europium-activated yttrium oxide in the blended mixture achieved 2,750 lumens output at approximately the same color temperature. The present lamps further exhibited a 5-8 percent lumen depreciation after 1,400 hours of burning which i9 comparable ; to the maintenance performance of the conventional deluxe-type fluorescent lamps tested.
The particular emission spectrum for the above illustrated lamp construction of the present invention is shown in FIG. 2. It can be noted from said visible emission curve that broad band emission over the spectral region extending Erom approximately
chromaticity values.
Embodiments of the invention will now be described with references to the accompanying drawings in which:
FIG~ l is a perspective view partially broken away of a fluorescent lamp construction in accordance with the present invention;
FIG. 2 i~ a vi~ible emission curve for a blended phosphor mixture in accordance with the present invention7 and FIG. 3 is a C.I.E. chromaticity diagram including the black body locus line with corresponding color temperatures indicated thereon for various deluxe-type fluorescent lamp~.
The particular phosphor combination herein employed utilizes one phosphor constituent emitting relatively broad band emissions in the lower spectral region from approximately 4,500 Angstroms to 5,900 Angstroms along with a specific rare earth oxide phosphor constituent exhibiting narrow band emission in the spectral energy region from approximately 6,000 Angstroms to about 6,150 Angstroms for higher emission efficiency and satisfactory color rendition at the desired color temperature. By varying the weight ratio of these phosphor constituents in the blended mixture as hereinafter described in greater detail, it becomes possible to achieve the same 1065~49 approximate color temperature that is emitted by conventional deluxe-type fluorescent lamps. The im-provement in composite emission results from the relatively higher emission efficiency of the rare earth oxide phosphor compared with that for the tin-activated orthophosphate phosphor now used in said conventional lamps and the present phosphor combination has also been found to provide this benefit, with no appreciable decrease in lamp maintenance.
Referring to FIG. l, there is shown a fluorescent lamp l comprising an elongated soda-lime silicate glass bulb 2 with a circular cross section.
The discharge assembly in said lamp has the usual electrode structure 3 at each end supported by in-lead wires 4 and 5 which extend through a glass press seal 6 in a mount stem 7 to the contacts of a base 8 affixed at opposite ends of the lamp. The dis-charge-sustaining filling in the sealed glass tube is an inert gas such as argon or a mixture of argon and other gases at a low pressure in combination with a small quantity of mercury to provide the low vapor pressure manner of lamp operation. The inner surface of the glass bulb iB provided with a phosphor coating 9 which is applied extending substantially the full length of the bulb and around the bulb circumferential inner wall.
To better illustrate the improvement obtained in emission behavior for the above type lamp construction utilizing the present phosphor combination as a blended mixture, various -40-WT12 lamps were constructed for comparison with conventional deluxe-type fluorescent lamps now utilizing strontium blue ~L065~49 halophosphate or strontium green halophosphate with tin-activated strontium orthophosphate in approximately equal weight proportions. The conventional deluxe white lamps exhibited approximately 2,100 lumens value at 100 hours with a color temperature within the color oval shown in FIG. 3 while the present phosphor combination utilizing an approximate 80 parts strontium green halophosphate with 20 parts europium-activated yttrium oxide in the blended mixture achieved 2,750 lumens output at approximately the same color temperature. The present lamps further exhibited a 5-8 percent lumen depreciation after 1,400 hours of burning which i9 comparable ; to the maintenance performance of the conventional deluxe-type fluorescent lamps tested.
The particular emission spectrum for the above illustrated lamp construction of the present invention is shown in FIG. 2. It can be noted from said visible emission curve that broad band emission over the spectral region extending Erom approximately
4,500 Angstroms to 5,900 Angstroms wave length i8 attributable to the proportion of strontium green halophosphate phosphor in the blended mixture having a chemical composition which can be represented by the structural formula: Srg.71Sb.052Mn.17(PO4)6 ~
.93 SrF2. The portion of said emission curve extending from approximately 5,8G0 Angstroms to 6,200 Angstroms wave length is attributable to the proportion of rare earth oxide phosphor in the blended mixture, said phosphor having a chemical composition which can also be represented by the structural formula:
Eu3 :Y203. A color-rendering index value of 82 was ~o65949 obtained for said lamp construction as measured by the generally accepted C.I.E. method. The x and y chromaticity values for said lamp construction in accordance with a further well-known C.I,E. method were found to be x = 0.404 and y = 0.395. Said chromaticity values lie within the same color oval shown in FIG. 3 for conventional deluxe white lamp~.
Comparable results are obtained with a dif-ferent phosphor combination in accordance with the present invention to provide a warm-white deluxe color emission having a color point within or adjacent the color oval shown in FIG. 3 for conventional deluxe warm-white lamps. Specifically, a high efficiency strontium yellow halophosphate phosphor having the structural formula: Sr8 56Sb 035 Mn 33 (P04)6 . .93 SrF2 i8 blended with europium-activated yttrium oxide in the proportions to provide a desired color point adjacent the black body locus line. Said particular phosphor blend comprised approximately 83 parts of the strontium yellow halophosphate phosphor and 17 parts of the europium-activated yttrium oxide phosphor which resulted in a 100 hour lumen output value of 2,900 lumens when tested in 40-WT12 lamps.
The x and y chromaticity values achieved with said mixture were x = 0.445 and y = 0.415 which corresponded to a color point adjacent the desired color oval.
Another exemplary example in accordance with the present invention is provided to illustrate the results obtained with a particular phosphor combi-nation providing a cool-white deluxe color emission at a higher efficiency than can be obtained with conventional deluxe-type phosphor blends, More i065949 particularly, a mixture containing 80 parts of a strontium blue-green halophosphate phosphor coacti-vated with antimony and manganese having the structural formula: Sr~ 85 Sb 062 Mn,05 (P4)6 '94 2 20 parts europium-activated yttrium oxide phosphor provided composite emission within the standard color oval shown in FIG. 3 for conventional deluxe cool-white lamps. The x and y chromaticity values for said mixture measured x = 0~374 and y = 0.364 utilizing the same C.I.E. method of measurement. A 40-WT12 type fluorescent lamp using said phosphor blend produced a 100 hour lumen output value of approximately 2,650 lumens along with a 90 color rendering index value.
A still further exampie for a daylight deluxe fluorescent lamp in accordance with the present invention is provided having a composite emission color point within or adjacent the color oval shown in FIG. 3 for conventional deluxe daylight lamps. Accordingly, 84 parts strontium blue halo-pho~phate phosphor having the structural formula:
Sr8.88 sb~068 Mn,011 (P4)6 ~ .92 Sr F2 were blended with 16 parts of the europium-activated yttrium oxide phosphor and the 40-WT12 lamps coated with said blend exhibited a 100 hour lumen output value of 2,650 lumens with a 93 C.I.E. color rendering index value. The x and y chromaticity values obtained by the same C.I.E. method of measurement previously employed were x - .313 and y = .346.
An explanation of the manner in which the desired emission color point is obtained with the present phosphor combination is also shown in FIG. 3.
~65949 L~-6936 The straight solid line appearing on said graph represents the color points obtained by compositional variation of the strontiumholoapatite phosphor within the general range previously given. More particularly, one point illustrated on said straight line is the color point exhibited by the strontium blue halophosphate phosphor herein employed while the second point illustrated on said straight line represents the , color point exhibited by the hereinbefore disclosed strontium green halophosphate phosphor. The color point for the europium-activated yttrium oxide phosphor herein employed is also shown on said graph which permits a second straight dash line to be drawn between said color point and the particular point on the solid line representing the color point of the employed halophosphate phosphor. It will be noted for the particular illustration shown wherein the strontium green halophosphate phosphor is blended with said Y203 : Eu phosphor that the dash line intersects the standard color oval for conven-tional deluxe white lamps. Such intersection demon-strates that color points within a particular color oval can be obtained by varying the weight proportion of the component phosphor materials. In like manner, it will be evident that compasable color emission characteristics within the color ovals shown for deluxe warm-white, deluxe cool-white, and deluxe daylight lamps are obtained by varying the weight proportions in the phosphor combination and utilizing other strontiumhaloapatite phosphor materials as hereinbefore disclosed.
From the above preferred embodiments it is _g_ also evident that a particular two component phosphor combination has been provided which achieves sig-nificantly more light output than with current deluxe phosphor blends in fluorescent lamps. It will also be apparent, however, that some modification can be made in the illustrated embodiments by compositional variation of the phosphor constituents without departing from the true spirit and scope of this invention, For example, it is already known to incorporate cad-mium as well as other modifying metal ions in theparticular strontium halophosphate phosphors above illustrated without appreciable influence upon the otherwise desired emission response. Consequently, it is intended to limit the present invention only by the scope of the appended claims.
.93 SrF2. The portion of said emission curve extending from approximately 5,8G0 Angstroms to 6,200 Angstroms wave length is attributable to the proportion of rare earth oxide phosphor in the blended mixture, said phosphor having a chemical composition which can also be represented by the structural formula:
Eu3 :Y203. A color-rendering index value of 82 was ~o65949 obtained for said lamp construction as measured by the generally accepted C.I.E. method. The x and y chromaticity values for said lamp construction in accordance with a further well-known C.I,E. method were found to be x = 0.404 and y = 0.395. Said chromaticity values lie within the same color oval shown in FIG. 3 for conventional deluxe white lamp~.
Comparable results are obtained with a dif-ferent phosphor combination in accordance with the present invention to provide a warm-white deluxe color emission having a color point within or adjacent the color oval shown in FIG. 3 for conventional deluxe warm-white lamps. Specifically, a high efficiency strontium yellow halophosphate phosphor having the structural formula: Sr8 56Sb 035 Mn 33 (P04)6 . .93 SrF2 i8 blended with europium-activated yttrium oxide in the proportions to provide a desired color point adjacent the black body locus line. Said particular phosphor blend comprised approximately 83 parts of the strontium yellow halophosphate phosphor and 17 parts of the europium-activated yttrium oxide phosphor which resulted in a 100 hour lumen output value of 2,900 lumens when tested in 40-WT12 lamps.
The x and y chromaticity values achieved with said mixture were x = 0.445 and y = 0.415 which corresponded to a color point adjacent the desired color oval.
Another exemplary example in accordance with the present invention is provided to illustrate the results obtained with a particular phosphor combi-nation providing a cool-white deluxe color emission at a higher efficiency than can be obtained with conventional deluxe-type phosphor blends, More i065949 particularly, a mixture containing 80 parts of a strontium blue-green halophosphate phosphor coacti-vated with antimony and manganese having the structural formula: Sr~ 85 Sb 062 Mn,05 (P4)6 '94 2 20 parts europium-activated yttrium oxide phosphor provided composite emission within the standard color oval shown in FIG. 3 for conventional deluxe cool-white lamps. The x and y chromaticity values for said mixture measured x = 0~374 and y = 0.364 utilizing the same C.I.E. method of measurement. A 40-WT12 type fluorescent lamp using said phosphor blend produced a 100 hour lumen output value of approximately 2,650 lumens along with a 90 color rendering index value.
A still further exampie for a daylight deluxe fluorescent lamp in accordance with the present invention is provided having a composite emission color point within or adjacent the color oval shown in FIG. 3 for conventional deluxe daylight lamps. Accordingly, 84 parts strontium blue halo-pho~phate phosphor having the structural formula:
Sr8.88 sb~068 Mn,011 (P4)6 ~ .92 Sr F2 were blended with 16 parts of the europium-activated yttrium oxide phosphor and the 40-WT12 lamps coated with said blend exhibited a 100 hour lumen output value of 2,650 lumens with a 93 C.I.E. color rendering index value. The x and y chromaticity values obtained by the same C.I.E. method of measurement previously employed were x - .313 and y = .346.
An explanation of the manner in which the desired emission color point is obtained with the present phosphor combination is also shown in FIG. 3.
~65949 L~-6936 The straight solid line appearing on said graph represents the color points obtained by compositional variation of the strontiumholoapatite phosphor within the general range previously given. More particularly, one point illustrated on said straight line is the color point exhibited by the strontium blue halophosphate phosphor herein employed while the second point illustrated on said straight line represents the , color point exhibited by the hereinbefore disclosed strontium green halophosphate phosphor. The color point for the europium-activated yttrium oxide phosphor herein employed is also shown on said graph which permits a second straight dash line to be drawn between said color point and the particular point on the solid line representing the color point of the employed halophosphate phosphor. It will be noted for the particular illustration shown wherein the strontium green halophosphate phosphor is blended with said Y203 : Eu phosphor that the dash line intersects the standard color oval for conven-tional deluxe white lamps. Such intersection demon-strates that color points within a particular color oval can be obtained by varying the weight proportion of the component phosphor materials. In like manner, it will be evident that compasable color emission characteristics within the color ovals shown for deluxe warm-white, deluxe cool-white, and deluxe daylight lamps are obtained by varying the weight proportions in the phosphor combination and utilizing other strontiumhaloapatite phosphor materials as hereinbefore disclosed.
From the above preferred embodiments it is _g_ also evident that a particular two component phosphor combination has been provided which achieves sig-nificantly more light output than with current deluxe phosphor blends in fluorescent lamps. It will also be apparent, however, that some modification can be made in the illustrated embodiments by compositional variation of the phosphor constituents without departing from the true spirit and scope of this invention, For example, it is already known to incorporate cad-mium as well as other modifying metal ions in theparticular strontium halophosphate phosphors above illustrated without appreciable influence upon the otherwise desired emission response. Consequently, it is intended to limit the present invention only by the scope of the appended claims.
Claims (5)
1. In a fluorescent lamp which includes a tubular-shaped lamp glass envelope, an electrode structure at each end of said glass envelope, a mercury and inert gas filling within said glass envelope, and a phosphor coating on the interior surface of said glass envelope, the improvement which comprises using as said phosphor coating a blended phosphor mixture of a strontium-haloapatite phosphor with europium-activated yttrium oxide phosphor, said strontium-haloapatite phosphor having the general formula:
Sr10-x-y Sbx Mny (PO4)6. A2 wherein A is a halide selected from F and C1 including combinations thereof, x is in the approximate range 0.04 to 0.15, and y is in the approximate range 0.01 to 0.42, and said phosphor mixture containing approximately 75 to 85 weight percent of said strontium-haloapatite phosphor.
Sr10-x-y Sbx Mny (PO4)6. A2 wherein A is a halide selected from F and C1 including combinations thereof, x is in the approximate range 0.04 to 0.15, and y is in the approximate range 0.01 to 0.42, and said phosphor mixture containing approximately 75 to 85 weight percent of said strontium-haloapatite phosphor.
2. A lamp as in claim 1, wherein said phosphor mixture is in parts by weight approximately 80 parts strontium green halophosphate phosphor with approximately 20 parts europium-activated yttrium oxide phosphor.
3. A lamp as in claim 1, wherein said phosphor mixture is in parts by weight approximately 83 parts strontium yellow halophosphate phosphor with approximately 17 parts europium-activated yttrium oxide phosphor.
4. A lamp as in claim 1, wherein said phosphor mixture is in parts by weight approximately 80 parts strontium blue-green halophosphate phosphor with approximately 20 parts europium-activated yttrium oxide phosphor.
5. A lamp as in claim 1, wherein said phosphor mixture is in parts by weight approximately 84 parts strontium blue halophosphate phosphor with approximately 16 parts europium-activated yttrium oxide phosphor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA262,312A CA1065949A (en) | 1976-09-29 | 1976-09-29 | Fluorescent lamp construction utilizing a mixture of two phospor materials |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA262,312A CA1065949A (en) | 1976-09-29 | 1976-09-29 | Fluorescent lamp construction utilizing a mixture of two phospor materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1065949A true CA1065949A (en) | 1979-11-06 |
Family
ID=4106965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA262,312A Expired CA1065949A (en) | 1976-09-29 | 1976-09-29 | Fluorescent lamp construction utilizing a mixture of two phospor materials |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1065949A (en) |
-
1976
- 1976-09-29 CA CA262,312A patent/CA1065949A/en not_active Expired
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