US3814969A - Gas discharge tube with phosphor coating and elongate electrodes - Google Patents

Gas discharge tube with phosphor coating and elongate electrodes Download PDF

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Publication number
US3814969A
US3814969A US00299909A US29990972A US3814969A US 3814969 A US3814969 A US 3814969A US 00299909 A US00299909 A US 00299909A US 29990972 A US29990972 A US 29990972A US 3814969 A US3814969 A US 3814969A
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United States
Prior art keywords
neon
percent
electrodes
activated
gas discharge
Prior art date
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Expired - Lifetime
Application number
US00299909A
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English (en)
Inventor
K Ueda
M Sangen
S Kamiya
H Ohtsuka
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Panasonic Holdings Corp
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Matsushita Electronics Corp
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Filing date
Publication date
Priority claimed from JP46084834A external-priority patent/JPS5139472B2/ja
Priority claimed from JP46084833A external-priority patent/JPS5139471B2/ja
Application filed by Matsushita Electronics Corp filed Critical Matsushita Electronics Corp
Application granted granted Critical
Publication of US3814969A publication Critical patent/US3814969A/en
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    • 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
    • C09K11/664—Halogenides
    • 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
    • C09K11/59—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing silicon
    • 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
    • C09K11/74—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing arsenic, antimony or bismuth
    • 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
    • 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
    • C09K11/7766—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
    • C09K11/7776—Vanadates; Chromates; Molybdates; Tungstates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps

Definitions

  • a gas discharge tube which comprises a glass tube, acoating of phosphor applied to the inner walls of the glass tube, a pair of electrodes disposed in parallel to each other along the substantial length of the glass tube, and some amounts of mercury and a neon-argon gas mixture or a neon-helium-argon gas mixture.
  • the present invention relates to generally a glow lamp and more particularly an improvement of a glow lamp of the type consisting of a pair of parallel electrodes and inert gases sealed into a glass tube whereby the phosphor coating applied to the inner walls of the glass tube may emit the light of a desired color by the mercury glow discharge.
  • Glow lamps of the type comprising a glass tube and, a pair of parallel electrodes sealed in a neon atmosphere contained within the glass tube have been widely used as indicator lights because they may be readily operated by connecting them to the electrical supply circuit through a ballast resistor and the reduced power consumption does not result in a corresponding reduction of brightness.
  • the neon glow lamps have been also widely used because the glow discharge is readily produced in the sealed neon gas, and neon glow lamps in various shapes are available. However the neon glow lamp generally can emit only one color ranging in wavelength from 650 to 750 nanometers.
  • argon is generally sealed into a glass tube containing also some amount of mercury.
  • the brightness of light in the visible range emitted from argon gas is extremely weak so that only the light emitted from the phosphor is perceived by the eyes.
  • the mobility of mercury ions in argon gas is so small that when the length of a pair of electrodes sealed in the glass tube is long the light emission along the whole length of the electrodes becomes extremely difficult. As a result, the electrodes of the glow lamp of the type described are inevitably limited to a shorter length.
  • One of the objects of the present invention is therefore to overcome the defects and problems encountered in the prior art glow lamps.
  • Another object of the present invention is to provide a glow lamp which may emit the light along the whole length of the electrodes thereof with a high luminous efficiency when operated at a practical current.
  • another object of the present invention is to provide the composition of gases sealed into a glass tube which may uniformly produce the light along the whole length of a pair of electrodes longer than 30 millimeters in length disposed in parallel to each other in the glass tube of a glow tube of the type having the coating of phosphor applied to the inner walls thereof, the glow lamp being operated at a normal current.
  • the inventor made extensive studies and experiments and found out that the gas mixture sealed into glass tube preferably consists of 5 percent by volume of a neon and 95 60 percent by volume of argon or neon-helium-argon gas mixture with helium being less than one half by volume of neon in addition to some amount of mercury.
  • the single FIGURE is a schematic sectional view of a gas discharge tube in accordance with the present invention.
  • a glass tube I has an inner diameter ranging from four to 15 millimeters and a length depending upon that of a pair of electrodes 3 and 4 which are disposed in parallel with and spaced apart from each other by a predetermined distance within the glass tube 1.
  • the inner wall of the glass tube 1 is covered with a coating 2 of phosphor, and the pair of electrodes 3 and 4 are supported by insulating blocks 5 and 6 respectively and are connected at one ends to lead wires 9 and 10, respectively, which extend air-tightly through one end or base 7 of the glass tube I.
  • the glass tube 1 contains some amounts of mercury 8 and the argon-neon gas containing 5 30 percent by volume of neon or neon-helium-argon gas mixture containing 5 30 percent by volume of neon and helium less than one half by volume of neon.
  • the glass tube 1 has an inner diameter less than 4 millimeters, the diameter of electrodes becomes too small so that the surface load becomes too great, thus resulting in blackening of the inner walls within a considerably short service life.
  • the glass tube 1 has an inner diameter greater than 15 milli- ,meters, the distance from the electrodes to the phosphor coating becomes too great so that sufficient brightness cannot be attained.
  • the pair of electrodes 3 and 4 may be conventional ones made of nickel, nickel alloy or nickel-plated steel wires.
  • the spacing between the pair of electrodes 3 and 4 is determined depending upon a voltage impressed between them and is for example of the order of 0.7 millimeters when the voltage is 200 220 volts. In this case, the discharge starting voltage is about volts at room temperature.
  • the length of a pair of electrodes is dependent upon the purpose of use and determines the composition of gases sealed into the glass tube.
  • the insulating blocks 5 and 6 are used to hold the pair of electrodes'3 and 4 in parallel so that they may not contact to each other even under vibrations, and are made of ceramics such as steatite or mica. It is not necessary to support both ends of the pair of electrodes by the insulating blocks, and only one end of the pair of electrodes may be supported by the insulating blocks if so desired.
  • the gas discharge tube in accordance with the present invention may also use any phosphor used in conventional fluorescent lamps, and the phosphors which may be excited to emit the light of a narrow spectrum such as divalent europium activated phosphate alkaline earth metals, divalent manganese activated zinc silicate, trivalent'europium activated yttrium vanadate, trivalent dysprosium activated yttrium vanadate, tetravalent manganese activated magnesium arsenate and tetravalent manganese activated magnesium germafluoride are especially effective when used in the gas discharge lamps which are used as indicator lamps.
  • the phosphors which may be excited to emit the ultra-violet rays may be coated to a glass tube which may transmit the ultra-violet rays.
  • the amount of mercury sealed into the glass tube is not so critical, but it is preferable that the amount of mercury is not much greater than that which would just saturate the lamp when it is turned on, in order to avoid the short-circuiting the pair of electrodes.
  • composition of gases sealed into the glass tube is one of the fundamental conditions for attaining the uniform light emission of the glow lamp type with the construction described above.
  • the composition of gases must be selected depending upon the length of electrodes, and it is necessary to seal some amounts of gases to improve the mobility of mercury ions in order to attain the uniform glow discharge throughout the whole length of electrodes. The latter condition is especially important when the length of electrodes becomes longer.
  • the uniformity of mercury glow discharge around the electrodes as well as the mercuryand neon-glows were extensively investigated by the inventors by varying the ratio of neon to argon. It was found out that when the ratio of neon is in excess of 30 percent, red light excited by the neon glow discharge becomes stronger while light emitted from the phosphor which is excited by the mercury glow discharge becomes weak so that the colors of the light emitted by the phosphor and by the neon glow discharge are mixed.
  • the gas mixture consisting of 30 percent of neon and 70 percent of argon may produce a desired lamp color.
  • the ratio of neon may be decreased. Especially when the ratio of neon is less than 5 percent the lamp color is not substantially different from that of a gas discharge tube containing only argon. Therefore the lower limit of the ratio of neon is considered 5 percent.
  • the gas mixture consisting of 30 percent of neon and 70 percent of argon is not sufficient to improve the mobility of mercury ions, so that the light cannot be produced uniformly along the whole length of the electrodes.
  • Helium may be also used to improve the mobility of mercury ions, but the brightness of helium emission spectrum in the visible region is so weak that helium is sealed in a glow discharge tube containing the long electrodes so as to produce the light along the whole length of the electrodes.
  • the inventors found out that the use of the gas mixture consisting of helium and argon will cause considerable damages to the electrodes.
  • the inventors made extensive studies and experiments in order to find out the suitable ratio among neon, argon and helium which may overcome the above described defect. It was found out that when the amount of helium is less than one half of that of neon the damages to the electrodes may be considerably reduced.
  • the gas mixture consisting of neon, argon and helium in fact serves to reduce the current load which is required to produce the uniform glow discharge along the whole length of the electrodes.
  • the current load of 1.5 mA per 10 millimeters is required to produce the uniform glow discharge along the whole length of the electrodes, but in case of the gas mixture consisting of 30 percent of neon, 10 percent of helium and 60 percent of argon, the uniform glow discharge may be produced by the current load of only 0.8 mA per 10 mm of electrode. in the former case, blackening of the inner walls of the glass tube takes place within a very short time, but in the latter case blackening is not observed even after a long service time.
  • the composition of the gas mixture consisting of neon, helium and argon may be selected in various manners.
  • the gas mixture consisting of 30 percent of neon and percent of argon or 25 percent of neon, 5 percent of helium and 70 percent of argon may be used when the length of the electrodes is of the order of millimeters.
  • the composition of the gas mixture consisting of neon, helium and argon will not cause a great difference in light produced as far as the amount of helium is less than one half of that of neon.
  • EXAMPLE 1 The coating of divalent europium activated strontium pyrophosphate was applied to the inner wall of the glass tube of 7 mm in inner diameter and mm in length, the phosphor used being the blue light emission phosphor with the peak wavelength of 4.200 A.
  • the pair of manganese-nickel alloy electrodes of l millimeter in diameter and 80 mm in length were disposed in parallel with and spaced apart from each other by 0.7 mm in the glass tube which contained 8 mg of mercury and the gas mixture consisting of 25 percent by volume of neon and 75 percent of argon at a pressure of 40 mmHg.
  • the pair of electrodes were firmly inserted into the holes of the blocks made of steatite capable of withstanding the heat up to 1,200C. In order to degas the electrodes they were heated in the inert gas atmosphere at about 800C.
  • the gas discharge tube was turned on at the voltage of 200 AC volts and the current of 10 mA. Blue light emission was normal and the desired spectrum energy distribution was attained.
  • the lamp color was green.
  • the lamp color was red.
  • the phosphor coatings were magnesium germafluoride and dysprosium activated yttrium vanadate, the lamp colors were deep red and yellow, respectively.
  • EXAMPLE 2 The phosphor coating of divalent europium activated strontium pyrophosphate was applied to the inner wall of a glass tube of mm in inner diameter and 160 mm in length.
  • the phosphor is a blue-light-emission phosphor with the peak wavelength of 4,200 A.
  • a pair of manganese-nickel alloy electrodes one millimeter in diameter and 140 mm in length were disposed in the glass tube in parallel with and spaced apart from each other by 0.7 mm,'and the gas mixture consisting of 26 percent of neon, 8 percent of helium and 66 percent of argon and the amount of l5 mg of mercury were sealed in the glass tube under the pressure of 40 mmHg.
  • the pair of electrodes were firmly inserted into the holes of the blocks made from steatite capable of withstanding the heat up to l,200C, and were degased in the inert gas atmosphere at about 800C.
  • the gas discharge tube thus obtained was turned on atthe AC voltage of 200 volts and a current of 10 mA. Blue light emission was normal and the desired spectrum distribution was obtained without causing the damages to the electrodes.
  • a filling in said glass tube consisting of mercury and an inert gas mixture consisting of 5-30 percent neon, helium in an amount less than one half of said neon, and the remainder argon.
  • a gas discharge tube as defined in claim 1 wherein said coating of phosphor consists of one of divalent europium activated phosphate alkaline earth metals, divalent manganese activated zinc silicate, trivalent europium activated yttrium vanadate, trivalent dysprosium activated yttrium vanadate, tetravalent manganese activated magnesium arsenate and tetravalent manganese activated magnesium germafluoride.
  • a gas discharge tube as defined in claim 3 wherein said coating of phosphor consists of one of divalent europium activated phosphate alkaline earth metals, divalent manganese activated zinc silicate, trivalent europium activated yttrium vanadate, trivalent dysprosium activated yttrium vanadate, tetravalent manganese activated magnesium arsenate and tetravalent manganese activated magnesium germafluoride.
  • a gas discharge tube as defined in claim 5 wherein said coating of phosphor consists of one of divalent europium activated phosphate alkaline. earth metals, divalent manganese activated zinc silicate, trivalent europium activated yttrium vanadate, trivalent dysprosium activated yttrium vanadate, tetravalent manganese activated magnesium arsenate and tetravalent manganese activated magnesium germafluoride.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Discharge Lamp (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Luminescent Compositions (AREA)
US00299909A 1971-10-25 1972-10-24 Gas discharge tube with phosphor coating and elongate electrodes Expired - Lifetime US3814969A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP46084834A JPS5139472B2 (ja) 1971-10-25 1971-10-25
JP46084833A JPS5139471B2 (ja) 1971-10-25 1971-10-25

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US3814969A true US3814969A (en) 1974-06-04

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US (1) US3814969A (ja)
CA (1) CA959912A (ja)
FR (1) FR2158271B1 (ja)
GB (1) GB1411806A (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4039889A (en) * 1976-02-25 1977-08-02 General Electric Company Blue-white glow lamp
US5761024A (en) * 1994-11-24 1998-06-02 Yazaki Corporation Discharge tube

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1842525A (en) * 1930-05-06 1932-01-26 Heintz & Kaufman Ltd Glow lamp
US2018974A (en) * 1932-01-19 1935-10-29 Rodalite Company Inc Gas filled electric lamp
US2063580A (en) * 1932-07-26 1936-12-08 Sirian Lamp Co Discharge lamp for producing modulated light
US2298581A (en) * 1940-01-22 1942-10-13 Abadie Jean Baptiste Jo Marcel Luminescent lamp bulb
US2525624A (en) * 1946-03-13 1950-10-10 William F Stahl Glow lamp combination
US2713629A (en) * 1950-09-05 1955-07-19 Walter V Etzkorn Luminous bodies
US2945977A (en) * 1957-03-28 1960-07-19 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Fluorescent glow discharge lamp

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1842525A (en) * 1930-05-06 1932-01-26 Heintz & Kaufman Ltd Glow lamp
US2018974A (en) * 1932-01-19 1935-10-29 Rodalite Company Inc Gas filled electric lamp
US2063580A (en) * 1932-07-26 1936-12-08 Sirian Lamp Co Discharge lamp for producing modulated light
US2298581A (en) * 1940-01-22 1942-10-13 Abadie Jean Baptiste Jo Marcel Luminescent lamp bulb
US2525624A (en) * 1946-03-13 1950-10-10 William F Stahl Glow lamp combination
US2713629A (en) * 1950-09-05 1955-07-19 Walter V Etzkorn Luminous bodies
US2945977A (en) * 1957-03-28 1960-07-19 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Fluorescent glow discharge lamp

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4039889A (en) * 1976-02-25 1977-08-02 General Electric Company Blue-white glow lamp
US5761024A (en) * 1994-11-24 1998-06-02 Yazaki Corporation Discharge tube

Also Published As

Publication number Publication date
CA959912A (en) 1974-12-24
DE2252417B2 (de) 1975-11-06
GB1411806A (en) 1975-10-29
FR2158271B1 (ja) 1975-06-13
FR2158271A1 (ja) 1973-06-15
DE2252417A1 (de) 1973-05-10

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