US3602757A - Multiple-luminescent layer improved lumen maintenance combination - Google Patents

Multiple-luminescent layer improved lumen maintenance combination Download PDF

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Publication number
US3602757A
US3602757A US835006A US3602757DA US3602757A US 3602757 A US3602757 A US 3602757A US 835006 A US835006 A US 835006A US 3602757D A US3602757D A US 3602757DA US 3602757 A US3602757 A US 3602757A
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United States
Prior art keywords
layer
combination
maintenance
specified
luminescent
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Expired - Lifetime
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US835006A
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English (en)
Inventor
Anselm Wachtel
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Philips North America LLC
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Westinghouse Electric Corp
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Assigned to NORTH AMERICAN PHILIPS ELECTRIC CORP. reassignment NORTH AMERICAN PHILIPS ELECTRIC CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/38—Devices for influencing the colour or wavelength of the light
    • H01J61/42—Devices for influencing the colour or wavelength of the light by transforming the wavelength of the light by luminescence
    • H01J61/48—Separate coatings of different luminous materials
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/66—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing germanium, tin or lead
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7737—Phosphates
    • C09K11/7738—Phosphates with alkaline earth metals
    • C09K11/7739—Phosphates with alkaline earth metals with halogens
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7783—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals one of which being europium
    • C09K11/7784—Chalcogenides
    • C09K11/7787—Oxides

Definitions

  • WITNESSESI INVENTOR 9 Anselm Wochtel 2 av ATTORNEY MULTIPLE-LUMINESCENT LAYER IMPROVED LUMEN MAINTENANCE COMBINATION BACKGROUND OF THE INVENTION
  • This maintenance characteristic varies considerably. It is, of course, a necessity for a commercial lamp that the maintenance characteristic meet some minimum standard no matter how good the initial output may be.
  • the most important factor in phosphor maintenance in a mercury discharge combination is the amount of high energy, short wavelength radiations are impinging upon the phosphor layer.
  • the phosphor can also degenerate from direct bombardment of mercury ions.
  • the luminescent combination comprises a source of ultraviolet radiation, which radiation impinges -upon the plural luminescent coatings on a light transmissive substrate.
  • the high maintenance layer upon which the ultraviolet radiations directly impinge screen a portion of the high energy, short wavelength radiations from the one or more layers over which the high maintenance layer is disposed.
  • FIGURE is a view partly in section of a fluorescent lamp embodiment of the present invention.
  • a standard low-pressure mercury vapor discharge device which serves as a substrate for the luminescent layers or coatings l4, 16, which are disposed on the interior surface of the envelope 12.
  • the envelope 12 is typically formed of soda-lime glass.
  • the conductive leaddns 18 are hermetically sealed through the envelope and ter minate internally in the electrodes across which the discharge is maintained.
  • the lamp typically includes a discharge sustaining fill of mercury and an insert starting gas as is well known in the art.
  • the first luminescent layer 14 serves as the first layer on the envelope 12.
  • This first layer 14 is by way of example a blend of the compositions Sr .,(P0 Cl: Eu which is taught by copending application Ser. No. 768,455 filed Oct. 17, 1968, owned by the present assignee, and the luminescent composition comprising the fired reaction product of 1.7 moles Zn0, 0.3 mole MgF 0.6 mole 6e0 0.4 mole Si0,, and 0.03 mole MnC0 described in copending application Ser. No. 834,971, filed concurrently herewith and owned by the present assignee.
  • the phosphor preferably is stabilized by an addition of lead and arsenic.
  • the blend comprises about 8 percent by weight of the strontium chlorophosphate material, about 47 percent by weight of the zinc silicogermanate, and the remainder is a readily volatilized transport medium with a binder such as nitrocellulose.
  • a binder such as nitrocellulose.
  • a layer 14 of this blend is coated onto the glass substrate, and this luminescent layer for a conventional 48 inch long, T-l2 soda-lime glass envelope comprises about 1.38 grams of the strontium chlorophosphate phosphor thoroughly blended with about 7.46 grams of the zinc silicogermanate phosphor.
  • the combination is now ready for application of a second layer.
  • the second layer luminescent material which has a very good lumen maintenance characteristic, is for example, yttrium-europium oxide, which is a well known generally red emitting phosphor.
  • a phosphor paint is prepared which is approximately ll percent by weight of phosphor with the remainder comprising a properly viscous transport medium with ethylcellulose binder. The viscosity of the paint is readily adjustable.
  • a relatively thin relatively uniform top layer can now be applied over the first layer in a coating which for this size envelope comprises about 1 gram of the yttrium-europium oxide phosphor.
  • the average particle size of the phosphor material used for the top layer is preferably less than the average particle size of the phosphor used for the first layer to insure effective coverage and protection of the first layer luminescent material.
  • the coated envelopes are then heated to vaporize the transport medium and binders. The lamp manufacture can now be completed, forming a low-pressure mercury discharge fluorescent lamp.
  • the effectiveness of the present double layered lamp is demonstrated by considering the following experimental data.
  • the -hour lumen maintenance percentages for the phosphors described in the foregoing example practicing the present invention, measured when each phosphor was operated alone in a fluorescent lamp are respectively, about 67 percent for the strontium chlorophosphate, about 75 percent for the zinc-magnesium silicogermanate, and about 98 percent for the yttrium-europium oxide material.
  • the red, green, and blue lumen output figures for the lamp described above were obtained at 0-hour and lllhours using a Barnes calorimeter, which is a standard analytic tool.
  • This device utilizes specifically absorptive filters over a properly responsive photocell.
  • the filters are supplied by the Coming Glass Co. and the amber X, filter is designated CS 3l09, while the blue X, filter is CS 573.
  • the green lumen output is determined using what is termed a Y filter designated CS 4-107 by Corning, and the blue lumen output by using a Z filter which is designated CS 5-72.
  • the maintenance of red light output from 0 hours to 100 hours was about 92 percent, for green about 89 percent, and for blue about 88 percent, with the maintenance for the total visible lumen output being about 94 percent.
  • the red, green and blue lumen maintenance figures for 100 hours were respectively 94 percent, 94 percent, and 88 percent, with a total lamp maintenance of 97 percent.
  • the 100 hour lumen maintenance value is a standard reference measurement point used in the industry, since a substantial portion of the lumen loss occurs typically in this time period.
  • the first layer of luminescent material coated on the glass substrate is a blend of the green emitting manganese activated zinc silicate, and the red emitting cadmium borate, which are both characterized by poor maintenance.
  • the second layer is formed of barium titanium phosphate which has a very good lumen maintenance. The ratios of these phosphors can be readily adjusted to provide a lamp with a generally white light output. The maintenance of the zinc silicate and the cadmium borate are both improved by the protective layer of barium titanium phosphate.
  • the first layer comprises cool white halophosphate phosphor, which is activated by well known proportions of manganese and antimony and a second layer comprises yttrium-europium oxide phosphor.
  • the proportions of these phosphors used again is easily varied to vary the spectral energy distribution of the overall light output.
  • the overall lumen maintenance is improved because the very high maintenance yttrium-europium oxide phosphor absorbs a high proportion of the very short wavelength ultraviolet radiation.
  • Another very high maintenance phosphor which lends itself to use as the top layer in a blend lamp according to the present invention is manganese activated calcium gallate.
  • Other such compositions will be readily suggested to those skilled in the art.
  • the relative amounts of the particular luminescent materials utilized in the plurality of distinct luminescent layers can be adjusted to provide a predetermined resultant spectral energy distribution.
  • a discharge lamp comprising a source of ultraviolet radiations which are directed upon a luminescent coating disposed on the inner surface of a light transmitting envelope which surrounds said source of ultraviolet radiations, and said luminescent coating comprises a plurality of different luminescent materials, the improvement which comprises:
  • said luminescent coating is disposed on said envelope as a plurality of distinct superimposed layers of different luminescent materials, a first of said layers coated directly on said envelope and comprising luminescent material which under prolonged and unscreened excitation by said ultraviolet radiations emits visible radiations of a first predetermined color but with a relatively poor maintenance of fluorescent response;
  • said additional layer of luminescent material under prolonged and unscreened excitation by said ultraviolet radiations emits visible radiations of a different predetermined color and with a relatively good maintenance of fluorescent response, said additional luminescent material layer serving to screen said first luminescent material layer from direct irradiation by said ultraviolet radiations, whereby the maintenance of fluorescent response of said first luminescent material layer and of said discharge lamp are both improved and the stability of the color emission of said lamp is improved.
  • said source of ultraviolet radiations is a high pressure mercury discharge device having an outer envelope disposed about said discharge device, with said luminescent material layers being disposed on the interior wall surface of the outer envelope.
  • said first layer comprises a blend of lead and arsenic stabilized manganese-activated zinc silicogermanate and europium-activated strontium chlorophosphate
  • said additional layer comprises yttrium-europium oxide.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Luminescent Compositions (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
US835006A 1969-06-20 1969-06-20 Multiple-luminescent layer improved lumen maintenance combination Expired - Lifetime US3602757A (en)

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US83500669A 1969-06-20 1969-06-20

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US (1) US3602757A (enrdf_load_stackoverflow)
BE (1) BE752300A (enrdf_load_stackoverflow)
DE (1) DE2029302A1 (enrdf_load_stackoverflow)
NL (1) NL7008975A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3707641A (en) * 1970-12-22 1972-12-26 Westinghouse Electric Corp Discharge device which utilizes a mixture of two fluorescent materials
US3858082A (en) * 1970-12-10 1974-12-31 Westinghouse Electric Corp Warm white lamp with normal output and improved color rendition
US4070598A (en) * 1976-11-08 1978-01-24 General Electric Company Fluorescent lamp with second phosphor layer
US4079287A (en) * 1975-09-25 1978-03-14 General Electric Company Fluorescent lamp construction utilizing a mixture of two phosphor materials
FR2379161A2 (fr) * 1977-01-28 1978-08-25 Gen Electric Lampe fuorescente
FR2458896A1 (fr) * 1979-06-11 1981-01-02 Gte Prod Corp Lampe fluorescente ayant deux couches de luminophores
US4305019A (en) * 1979-12-31 1981-12-08 Westinghouse Electric Corp. Warm-white fluorescent lamp having good efficacy and color rendering and using special phosphor blend as separate undercoat
EP0042126A3 (en) * 1980-06-13 1982-09-15 Gte Products Corporation Fluorescent lamp having two phosphor layers
US4447756A (en) * 1980-04-08 1984-05-08 Tokyo Shibaura Denki Kabushiki Kaisha Fluorescent lamp with layer of plural phosphors having different particle sizes
US4914346A (en) * 1983-03-04 1990-04-03 Gte Products Corporation Lamp envelope having a luminescent material on the interior surface thereof, method of applying said material, and material to be applied
EP1174905A1 (en) * 2000-07-07 2002-01-23 Matsushita Electric Industrial Co., Ltd. Fluorescent lamp, high intensity discharge lamp and incandescent lamp with improved luminous efficiency
US20040095058A1 (en) * 2000-08-10 2004-05-20 Arunava Dutta Display device having reduced color shift during life

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3858082A (en) * 1970-12-10 1974-12-31 Westinghouse Electric Corp Warm white lamp with normal output and improved color rendition
US3707641A (en) * 1970-12-22 1972-12-26 Westinghouse Electric Corp Discharge device which utilizes a mixture of two fluorescent materials
US4079287A (en) * 1975-09-25 1978-03-14 General Electric Company Fluorescent lamp construction utilizing a mixture of two phosphor materials
US4070598A (en) * 1976-11-08 1978-01-24 General Electric Company Fluorescent lamp with second phosphor layer
FR2379161A2 (fr) * 1977-01-28 1978-08-25 Gen Electric Lampe fuorescente
US4431941A (en) * 1979-06-11 1984-02-14 Gte Products Corporation Fluorescent lamp having double phosphor layer
FR2458896A1 (fr) * 1979-06-11 1981-01-02 Gte Prod Corp Lampe fluorescente ayant deux couches de luminophores
US4305019A (en) * 1979-12-31 1981-12-08 Westinghouse Electric Corp. Warm-white fluorescent lamp having good efficacy and color rendering and using special phosphor blend as separate undercoat
US4447756A (en) * 1980-04-08 1984-05-08 Tokyo Shibaura Denki Kabushiki Kaisha Fluorescent lamp with layer of plural phosphors having different particle sizes
EP0042126A3 (en) * 1980-06-13 1982-09-15 Gte Products Corporation Fluorescent lamp having two phosphor layers
US4678966A (en) * 1980-06-13 1987-07-07 Gte Products Corporation Fluorescent lamp having two phosphor layers
US4914346A (en) * 1983-03-04 1990-04-03 Gte Products Corporation Lamp envelope having a luminescent material on the interior surface thereof, method of applying said material, and material to be applied
EP1174905A1 (en) * 2000-07-07 2002-01-23 Matsushita Electric Industrial Co., Ltd. Fluorescent lamp, high intensity discharge lamp and incandescent lamp with improved luminous efficiency
US20020070682A1 (en) * 2000-07-07 2002-06-13 Tomoko Atagi Fluorescent lamp and high intensity discharge lamp with improved luminous efficiency
US6906475B2 (en) 2000-07-07 2005-06-14 Matsushita Electric Industrial Co., Ltd. Fluorescent lamp and high intensity discharge lamp with improved luminous efficiency
US20040095058A1 (en) * 2000-08-10 2004-05-20 Arunava Dutta Display device having reduced color shift during life
US7030549B2 (en) * 2000-08-10 2006-04-18 Osram Sylvania Inc. Display device having reduced color shift during life

Also Published As

Publication number Publication date
DE2029302A1 (enrdf_load_stackoverflow) 1970-12-23
BE752300A (fr) 1970-12-01
NL7008975A (enrdf_load_stackoverflow) 1970-12-22

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AS Assignment

Owner name: NORTH AMERICAN PHILIPS ELECTRIC CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:004113/0393

Effective date: 19830316